chore: bump version to 4.1.3 (build 120)

- Fix M4A/ALAC scan silently failing on Samsung by adding proper fallback
  to scanFromFilename when ReadM4ATags fails (consistent with MP3/FLAC/Ogg)
- Propagate displayNameHint to all format scanners so fd numbers (214, 207)
  no longer appear as track names when /proc/self/fd/ paths are used
- Cache /proc/self/fd/ readability in Kotlin to skip failed attempts after
  first failure, reducing error log noise and improving scan speed on Samsung
- Fix Qobuz download returning wrong album cover when track exists on
  multiple albums by preferring req.CoverURL over API default
- Fix FFmpeg M4A metadata save failing with 'codec not currently supported
  in container' by forcing mp4 muxer instead of ipod when cover art present
- Clean up FLAC SAF temp file after metadata write-back (was leaking)
- Update LRC lyrics tag to credit Paxsenix API
- Remove log message truncation, defer to UI preview truncation instead

.fvmrc

@@ -1,3 +1,3 @@
 {
-  "flutter": "3.41.5"
+  "flutter": "3.41.4"
 }

.github/ISSUE_TEMPLATE/config.yml

@@ -4,5 +4,5 @@ contact_links:
     url: https://github.com/zarzet/SpotiFLAC-Mobile#readme
     about: Check the README for setup instructions and FAQ
   - name: Extension Development Guide
-    url: https://spotiflac.zarz.moe/docs
+    url: https://zarz.moe/docs
     about: Documentation for building SpotiFLAC extensions

.github/workflows/release.yml

@@ -71,7 +71,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v6
         with:
-          go-version: "1.25.8"
+          go-version: "1.25.7"
           cache-dependency-path: go_backend/go.sum
 
       # Cache Gradle for faster builds
@@ -93,12 +93,12 @@ jobs:
           # Accept licenses
           yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager --licenses || true
 
-          # Install NDK r29 (supports 16KB page size for Android 15+)
+          # Install NDK r27d LTS (required for 16KB page size support on Android 15+)
           # Platform android-36 and build-tools 36.0.0 for targetSdk 36 (Android 16)
-          $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;29.0.14206865" "platforms;android-36" "build-tools;36.0.0"
+          $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;27.3.13750724" "platforms;android-36" "build-tools;36.0.0"
 
           # Set NDK path
-          echo "ANDROID_NDK_HOME=$ANDROID_HOME/ndk/29.0.14206865" >> $GITHUB_ENV
+          echo "ANDROID_NDK_HOME=$ANDROID_HOME/ndk/27.3.13750724" >> $GITHUB_ENV
 
       - name: Install gomobile
         run: |
@@ -164,22 +164,17 @@ jobs:
           path: build/app/outputs/flutter-apk/SpotiFLAC-*.apk
 
   build-ios:
-    runs-on: macos-15
+    runs-on: macos-latest
     needs: get-version # Only depends on version, NOT android build!
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
 
-      - name: Select Xcode 26.1.1
-        run: |
-          sudo xcode-select -s /Applications/Xcode_26.1.1.app
-          xcodebuild -version
-
       - name: Setup Go
         uses: actions/setup-go@v6
         with:
-          go-version: "1.25.8"
+          go-version: "1.25.7"
           cache-dependency-path: go_backend/go.sum
 
       # Cache CocoaPods

.gitignore

@@ -77,7 +77,6 @@ flutter_*.log
 # Development tools
 tool/
 .claude/settings.local.json
-.playwright-mcp/
 
 # FVM Version Cache
 .fvm/

README.md

@@ -7,8 +7,8 @@
 </picture>
 
 <p align="center">
-  <a href="https://trendshift.io/repositories/25971" target="_blank">
-    <img src="https://trendshift.io/api/badge/repositories/25971" alt="spotiflacapp%2FSpotiFLAC-Mobile | Trendshift" width="250" height="55">
+  <a href="https://trendshift.io/repositories/17247">
+    <img src="https://trendshift.io/api/badge/repositories/17247" alt="zarzet%2FSpotiFLAC-Mobile | Trendshift" width="250" height="55">
   </a>
 </p>
 
@@ -166,21 +166,9 @@ Interested in contributing? Check out the [Contributing Guide](CONTRIBUTING.md)
 
 | | | | | |
 |---|---|---|---|---|
-| [MusicDL](https://www.musicdl.me) | [LRCLib](https://lrclib.net) | [Paxsenix](https://lyrics.paxsenix.org) | [Cobalt](https://cobalt.tools) | [Song.link](https://song.link) |
-| [IDHS](https://github.com/sjdonado/idonthavespotify) |  |  |  |  |
-
----
-
-## Disclaimer
-
-This repository and its contents are provided strictly for educational and research purposes. The software is provided "as-is" without warranty of any kind, express or implied, as stated in the [MIT License](LICENSE).
-
-- No copyrighted content is hosted, stored, mirrored, or distributed by this repository.
-- Users must ensure that their use of this software is properly authorized and complies with all applicable laws, regulations, and third-party terms of service.
-- This software is provided free of charge by the maintainer. If you paid a third party for access to this software in its original form from this repository, you may have been misled or scammed. Any redistribution or commercial use by third parties must comply with the terms of the repository license. No affiliation, endorsement, or support by the maintainer is implied unless explicitly stated in writing.
-- SpotiFLAC Mobile is an independent project. It is not affiliated with, endorsed by, or connected to any other project or version on other platforms that may share a similar name. The maintainer of this repository has no control over or responsibility for third-party projects.
-- The author(s) disclaim all liability for any direct, indirect, incidental, or consequential damages arising from the use or misuse of this software. Users assume all risk associated with its use.
-- If you are a copyright holder or authorized representative and believe this repository infringes upon your rights, please contact the maintainer with sufficient detail (including relevant URLs and proof of ownership). The matter will be promptly investigated and appropriate action will be taken, which may include removal of the referenced material.
+| [hifi-api](https://github.com/binimum/hifi-api) | [music.binimum.org](https://music.binimum.org) | [qqdl.site](https://qqdl.site) | [squid.wtf](https://squid.wtf) | [spotisaver.net](https://spotisaver.net) |
+| [dabmusic.xyz](https://dabmusic.xyz) | [AfkarXYZ](https://github.com/afkarxyz) | [LRCLib](https://lrclib.net) | [Paxsenix](https://lyrics.paxsenix.org) | [Cobalt](https://cobalt.tools) |
+| [qwkuns.me](https://qwkuns.me) | [SpotubeDL](https://spotubedl.com) | [Song.link](https://song.link) | [IDHS](https://github.com/sjdonado/idonthavespotify) | |
 
 > [!TIP]
 > **Star the repo** to get notified about all new releases directly from GitHub.

analysis_options.yaml

@@ -36,11 +36,7 @@ linter:
   rules:
     # avoid_print: false  # Uncomment to disable the `avoid_print` rule
     # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
-    always_declare_return_types: true
     avoid_dynamic_calls: true
-    avoid_types_as_parameter_names: true
-    strict_top_level_inference: true
-    type_annotate_public_apis: true
     cancel_subscriptions: true
     close_sinks: true
 

android/app/build.gradle.kts

@@ -20,10 +20,6 @@ android {
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
-    buildFeatures {
-        buildConfig = true
-    }
-
     compileOptions {
         isCoreLibraryDesugaringEnabled = true
         sourceCompatibility = JavaVersion.VERSION_17
@@ -61,18 +57,6 @@ android {
     }
 
     buildTypes {
-        getByName("debug") {
-            ndk {
-                debugSymbolLevel = "FULL"
-            }
-        }
-
-        getByName("profile") {
-            ndk {
-                debugSymbolLevel = "FULL"
-            }
-        }
-
         release {
             // For local builds: use release signing if key.properties exists
             // For CI builds: APK is signed by GitHub Action after build
@@ -87,9 +71,6 @@ android {
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
-            ndk {
-                debugSymbolLevel = "FULL"
-            }
         }
     }
     
@@ -123,6 +104,5 @@ dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.10.2")
     implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.10.0")
     implementation("androidx.documentfile:documentfile:1.1.0")
-    implementation("androidx.activity:activity-ktx:1.13.0")
-    implementation("com.antonkarpenko:ffmpeg-kit-full:2.1.0")
+    implementation("androidx.activity:activity-ktx:1.12.3")
 }

android/app/src/main/AndroidManifest.xml

@@ -18,7 +18,7 @@
     <uses-permission android:name="android.permission.WAKE_LOCK" />
 
     <application
-        android:label="SpotiFLAC Mobile"
+        android:label="SpotiFLAC"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher"
         android:usesCleartextTraffic="false"
@@ -86,20 +86,6 @@
                 <category android:name="android.intent.category.BROWSABLE" />
                 <data android:scheme="https" android:host="music.youtube.com" />
             </intent-filter>
-
-            <!-- Extension OAuth (PKCE) redirect: spotiflac://callback?code=...&state=<extension_id> -->
-            <intent-filter>
-                <action android:name="android.intent.action.VIEW" />
-                <category android:name="android.intent.category.DEFAULT" />
-                <category android:name="android.intent.category.BROWSABLE" />
-                <data android:scheme="spotiflac" android:host="callback" />
-            </intent-filter>
-            <intent-filter>
-                <action android:name="android.intent.action.VIEW" />
-                <category android:name="android.intent.category.DEFAULT" />
-                <category android:name="android.intent.category.BROWSABLE" />
-                <data android:scheme="spotiflac" android:host="spotify-callback" />
-            </intent-filter>
         </activity>
 
         <!-- Download Service -->
@@ -108,6 +94,24 @@
             android:exported="false"
             android:foregroundServiceType="dataSync" />
 
+        <!-- Audio playback service for media notification / background audio -->
+        <service
+            android:name="com.ryanheise.audioservice.AudioService"
+            android:exported="true"
+            android:foregroundServiceType="mediaPlayback">
+            <intent-filter>
+                <action android:name="android.media.browse.MediaBrowserService" />
+            </intent-filter>
+        </service>
+
+        <receiver
+            android:name="com.ryanheise.audioservice.MediaButtonReceiver"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MEDIA_BUTTON" />
+            </intent-filter>
+        </receiver>
+
         <!-- flutter_local_notifications receivers -->
         <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
         <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">

android/app/src/main/kotlin/com/zarz/spotiflac/MainActivity.kt

@@ -4,7 +4,6 @@ import android.app.Activity
 import android.content.Intent
 import android.net.Uri
 import android.os.Build
-import android.os.Bundle
 import androidx.activity.OnBackPressedCallback
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.documentfile.provider.DocumentFile
@@ -43,9 +42,6 @@ class MainActivity: FlutterFragmentActivity() {
         "com.zarz.spotiflac/library_scan_progress_stream"
     private val DOWNLOAD_PROGRESS_STREAM_POLLING_INTERVAL_MS = 1200L
     private val LIBRARY_SCAN_PROGRESS_STREAM_POLLING_INTERVAL_MS = 200L
-    private val MAX_SAF_DISPLAY_NAME_UTF8_BYTES = 180
-    private val LARGE_JSON_RESULT_FILE_KEY = "__json_file"
-    private val LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES = 256 * 1024
     private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
     private var pendingSafTreeResult: MethodChannel.Result? = null
     private val safScanLock = Any()
@@ -54,7 +50,6 @@ class MainActivity: FlutterFragmentActivity() {
     private var downloadProgressStreamJob: Job? = null
     private var downloadProgressEventSink: EventChannel.EventSink? = null
     private var lastDownloadProgressPayload: String? = null
-    private var lastDownloadProgressSeq = 0L
     private var libraryScanProgressStreamJob: Job? = null
     private var libraryScanProgressEventSink: EventChannel.EventSink? = null
     private var lastLibraryScanProgressPayload: String? = null
@@ -168,6 +163,10 @@ class MainActivity: FlutterFragmentActivity() {
             "sm-t225",
             "hammerhead",
         )
+        /**
+         * Check if device should use Skia instead of Impeller.
+         * Returns true for devices with old/problematic GPUs or old Android versions.
+         */
         private fun shouldDisableImpeller(): Boolean {
             val hardware = Build.HARDWARE.lowercase(Locale.ROOT)
             val board = Build.BOARD.lowercase(Locale.ROOT)
@@ -216,6 +215,7 @@ class MainActivity: FlutterFragmentActivity() {
         }
 
     /**
+     * Try to get GPU renderer string.
      * Note: This may return empty on some devices before OpenGL context is created.
      */
         private fun getGpuRenderer(): String {
@@ -303,7 +303,7 @@ class MainActivity: FlutterFragmentActivity() {
 
     private fun mimeTypeForExt(ext: String?): String {
         return when (normalizeExt(ext)) {
-            ".m4a", ".mp4" -> "audio/mp4"
+            ".m4a" -> "audio/mp4"
             ".mp3" -> "audio/mpeg"
             ".opus" -> "audio/ogg"
             ".flac" -> "audio/flac"
@@ -313,62 +313,7 @@ class MainActivity: FlutterFragmentActivity() {
     }
 
     private fun sanitizeFilename(name: String): String {
-        var sanitized = name
-            .replace("/", " ")
-            .replace(Regex("[\\\\:*?\"<>|]"), " ")
-            .filter { ch ->
-                val code = ch.code
-                !((code < 0x20 && ch != '\t' && ch != '\n' && ch != '\r') ||
-                    code == 0x7F ||
-                    (Character.isISOControl(ch) && ch != '\t' && ch != '\n' && ch != '\r'))
-            }
-            .trim()
-            .trim('.', ' ')
-
-        sanitized = sanitized
-            .replace(Regex("\\s+"), " ")
-            .replace(Regex("_+"), "_")
-            .trim('_', ' ')
-
-        sanitized = truncateSafDisplayName(sanitized, MAX_SAF_DISPLAY_NAME_UTF8_BYTES)
-        sanitized = sanitized.trim().trim('.', ' ').trim('_', ' ')
-        return if (sanitized.isBlank()) "Unknown" else sanitized
-    }
-
-    private fun truncateSafDisplayName(name: String, maxBytes: Int): String {
-        if (maxBytes <= 0 || name.toByteArray(Charsets.UTF_8).size <= maxBytes) return name
-
-        val dotIndex = name.lastIndexOf('.')
-        val ext = if (
-            dotIndex > 0 &&
-            dotIndex < name.length - 1 &&
-            name.length - dotIndex <= 10
-        ) {
-            name.substring(dotIndex)
-        } else {
-            ""
-        }
-        val stem = if (ext.isNotEmpty()) name.substring(0, dotIndex) else name
-        val maxStemBytes = (maxBytes - ext.toByteArray(Charsets.UTF_8).size).coerceAtLeast(1)
-        return truncateUtf8Bytes(stem, maxStemBytes).trim().trim('.', ' ').trim('_', ' ') + ext
-    }
-
-    private fun truncateUtf8Bytes(value: String, maxBytes: Int): String {
-        if (maxBytes <= 0 || value.toByteArray(Charsets.UTF_8).size <= maxBytes) return value
-
-        val builder = StringBuilder()
-        var usedBytes = 0
-        var index = 0
-        while (index < value.length) {
-            val codePoint = value.codePointAt(index)
-            val char = String(Character.toChars(codePoint))
-            val charBytes = char.toByteArray(Charsets.UTF_8).size
-            if (usedBytes + charBytes > maxBytes) break
-            builder.append(char)
-            usedBytes += charBytes
-            index += Character.charCount(codePoint)
-        }
-        return builder.toString()
+        return name.replace(Regex("[\\\\/:*?\"<>|]"), "_").trim()
     }
 
     private fun sanitizeRelativeDir(relativeDir: String): String {
@@ -428,43 +373,6 @@ class MainActivity: FlutterFragmentActivity() {
         return current
     }
 
-    private fun createOrReuseDocumentFile(
-        parent: DocumentFile,
-        mimeType: String,
-        fileName: String
-    ): DocumentFile? {
-        val safeFileName = sanitizeFilename(fileName)
-        if (safeFileName.isBlank()) return null
-
-        synchronized(safDirLock) {
-            val existing = parent.findFile(safeFileName)
-            if (existing != null && existing.isFile) {
-                return existing
-            }
-
-            val created = parent.createFile(mimeType, safeFileName) ?: return null
-            val createdName = created.name ?: safeFileName
-            if (createdName == safeFileName) {
-                return created
-            }
-
-            // SAF can auto-rename to "name (1)" when another writer wins the race
-            // between findFile() and createFile(). Prefer the exact sibling if it
-            // appeared, and discard the duplicate document we just created.
-            val winner = parent.findFile(safeFileName)
-            if (winner != null && winner.isFile) {
-                if (winner.uri != created.uri) {
-                    try {
-                        created.delete()
-                    } catch (_: Exception) {}
-                }
-                return winner
-            }
-
-            return created
-        }
-    }
-
     private fun resetSafScanProgress() {
         synchronized(safScanLock) {
             safScanProgress = SafScanProgress()
@@ -531,46 +439,17 @@ class MainActivity: FlutterFragmentActivity() {
         }
     }
 
-    private fun bridgeJsonResult(payload: String): Any {
-        if (payload.toByteArray(Charsets.UTF_8).size < LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES) {
-            return payload
-        }
-
-        return try {
-            val file = File(cacheDir, "bridge_json_${System.nanoTime()}.json")
-            file.writeText(payload, Charsets.UTF_8)
-            mapOf(LARGE_JSON_RESULT_FILE_KEY to file.absolutePath)
-        } catch (e: Exception) {
-            android.util.Log.w(
-                "SpotiFLAC",
-                "Failed to spill large bridge JSON result to file: ${e.message}",
-            )
-            payload
-        }
-    }
-
-    private fun updateDownloadProgressSeq(payload: String) {
-        try {
-            val seq = JSONObject(payload).optLong("seq", lastDownloadProgressSeq)
-            if (seq > lastDownloadProgressSeq) {
-                lastDownloadProgressSeq = seq
-            }
-        } catch (_: Exception) {}
-    }
-
     private fun startDownloadProgressStream(sink: EventChannel.EventSink) {
         stopDownloadProgressStream()
         downloadProgressEventSink = sink
         lastDownloadProgressPayload = null
-        lastDownloadProgressSeq = 0L
         downloadProgressStreamJob = scope.launch {
             while (isActive && downloadProgressEventSink === sink) {
                 try {
                     val payload = withContext(Dispatchers.IO) {
-                        Gobackend.getAllDownloadProgressDelta(lastDownloadProgressSeq)
+                        Gobackend.getAllDownloadProgress()
                     }
-                    if (payload.isNotEmpty() && payload != lastDownloadProgressPayload) {
-                        updateDownloadProgressSeq(payload)
+                    if (payload != lastDownloadProgressPayload) {
                         lastDownloadProgressPayload = payload
                         sink.success(parseJsonPayload(payload))
                     }
@@ -590,7 +469,6 @@ class MainActivity: FlutterFragmentActivity() {
         downloadProgressStreamJob = null
         downloadProgressEventSink = null
         lastDownloadProgressPayload = null
-        lastDownloadProgressSeq = 0L
     }
 
     private fun startLibraryScanProgressStream(sink: EventChannel.EventSink) {
@@ -637,17 +515,17 @@ class MainActivity: FlutterFragmentActivity() {
         lastLibraryScanProgressPayload = null
     }
 
-    private fun loadExistingFilesFromSnapshot(snapshotPath: String): MutableMap<String, Long> {
-        val result = mutableMapOf<String, Long>()
+    private fun loadExistingFilesJsonFromSnapshot(snapshotPath: String): String {
         if (snapshotPath.isBlank()) {
-            return result
+            return "{}"
         }
 
         val snapshotFile = File(snapshotPath)
         if (!snapshotFile.exists()) {
-            return result
+            return "{}"
         }
 
+        val result = JSONObject()
         snapshotFile.forEachLine { line ->
             if (line.isBlank()) return@forEachLine
             val separatorIndex = line.indexOf('\t')
@@ -657,10 +535,10 @@ class MainActivity: FlutterFragmentActivity() {
             val modTime = line.substring(0, separatorIndex).toLongOrNull() ?: 0L
             val filePath = line.substring(separatorIndex + 1)
             if (filePath.isNotEmpty()) {
-                result[filePath] = modTime
+                result.put(filePath, modTime)
             }
         }
-        return result
+        return result.toString()
     }
 
     private fun resolveSafFile(treeUriStr: String, relativeDir: String, fileName: String): String {
@@ -724,6 +602,16 @@ class MainActivity: FlutterFragmentActivity() {
         return obj.toString()
     }
 
+    private fun buildSafFileName(req: JSONObject, outputExt: String): String {
+        val provided = req.optString("saf_file_name", "")
+        if (provided.isNotBlank()) return sanitizeFilename(provided)
+
+        val trackName = req.optString("track_name", "track")
+        val artistName = req.optString("artist_name", "")
+        val baseName = if (artistName.isNotBlank()) "$artistName - $trackName" else trackName
+        return sanitizeFilename(baseName) + outputExt
+    }
+
     private fun errorJson(message: String): String {
         val obj = JSONObject()
         obj.put("success", false)
@@ -771,7 +659,6 @@ class MainActivity: FlutterFragmentActivity() {
     private fun extFromFileName(name: String): String {
         return when {
             name.endsWith(".m4a") -> ".m4a"
-            name.endsWith(".mp4") -> ".mp4"
             name.endsWith(".mp3") -> ".mp3"
             name.endsWith(".opus") -> ".opus"
             name.endsWith(".flac") -> ".flac"
@@ -1005,6 +892,95 @@ class MainActivity: FlutterFragmentActivity() {
         return true
     }
 
+    private fun handleSafDownload(requestJson: String, downloader: (String) -> String): String {
+        val req = JSONObject(requestJson)
+        val storageMode = req.optString("storage_mode", "")
+        val treeUriStr = req.optString("saf_tree_uri", "")
+        if (storageMode != "saf" || treeUriStr.isBlank()) {
+            return downloader(requestJson)
+        }
+
+        val treeUri = Uri.parse(treeUriStr)
+        val relativeDir = sanitizeRelativeDir(req.optString("saf_relative_dir", ""))
+        val outputExt = normalizeExt(req.optString("saf_output_ext", ""))
+        val mimeType = mimeTypeForExt(outputExt)
+        val fileName = buildSafFileName(req, outputExt)
+
+        val existingDir = findDocumentDir(treeUri, relativeDir)
+        if (existingDir != null) {
+            val existing = existingDir.findFile(fileName)
+            if (existing != null && existing.isFile && existing.length() > 0) {
+                val obj = JSONObject()
+                obj.put("success", true)
+                obj.put("message", "File already exists")
+                obj.put("file_path", existing.uri.toString())
+                obj.put("file_name", existing.name ?: fileName)
+                obj.put("already_exists", true)
+                return obj.toString()
+            }
+        }
+
+        val targetDir = ensureDocumentDir(treeUri, relativeDir)
+            ?: return errorJson("Failed to access SAF directory")
+
+        val existingFile = targetDir.findFile(fileName)
+        val document = existingFile ?: targetDir.createFile(mimeType, fileName)
+            ?: return errorJson("Failed to create SAF file")
+
+        val pfd = contentResolver.openFileDescriptor(document.uri, "rw")
+            ?: return errorJson("Failed to open SAF file")
+
+        var detachedFd: Int? = null
+        try {
+            // Prefer handing off a detached FD directly to Go.
+            // Some devices/providers reject re-opening /proc/self/fd/* with permission denied.
+            detachedFd = pfd.detachFd()
+            req.put("output_path", "")
+            req.put("output_fd", detachedFd)
+            req.put("output_ext", outputExt)
+            val response = downloader(req.toString())
+            val respObj = JSONObject(response)
+            if (respObj.optBoolean("success", false)) {
+                // Extension providers write to a local temp path instead of the SAF FD.
+                val goFilePath = respObj.optString("file_path", "")
+                if (goFilePath.isNotEmpty() &&
+                    !goFilePath.startsWith("content://") &&
+                    !goFilePath.startsWith("/proc/self/fd/")
+                ) {
+                    try {
+                        val srcFile = java.io.File(goFilePath)
+                        if (srcFile.exists() && srcFile.length() > 0) {
+                            contentResolver.openOutputStream(document.uri, "wt")?.use { output ->
+                                srcFile.inputStream().use { input ->
+                                    input.copyTo(output)
+                                }
+                            }
+                            srcFile.delete()
+                        }
+                    } catch (e: Exception) {
+                        android.util.Log.w("SpotiFLAC", "Failed to copy extension output to SAF: ${e.message}")
+                    }
+                }
+                respObj.put("file_path", document.uri.toString())
+                respObj.put("file_name", document.name ?: fileName)
+            } else {
+                document.delete()
+            }
+            return respObj.toString()
+        } catch (e: Exception) {
+            document.delete()
+            return errorJson("SAF download failed: ${e.message}")
+        } finally {
+            // If detachFd() failed before handoff, close original ParcelFileDescriptor.
+            // Otherwise Go owns the detached raw FD and is responsible for closing it.
+            if (detachedFd == null) {
+                try {
+                    pfd.close()
+                } catch (_: Exception) {}
+            }
+        }
+    }
+
     /**
      * Get the parent DocumentFile directory for a SAF document URI.
      * The child URI must be a tree-based document URI (e.g. from SAF tree scan).
@@ -1393,22 +1369,6 @@ class MainActivity: FlutterFragmentActivity() {
      * @return JSON object with new/changed files and removed URIs
      */
     private fun scanSafTreeIncremental(treeUriStr: String, existingFilesJson: String): String {
-        val existingFiles = mutableMapOf<String, Long>()
-        try {
-            val obj = JSONObject(existingFilesJson)
-            val keys = obj.keys()
-            while (keys.hasNext()) {
-                val key = keys.next()
-                existingFiles[key] = obj.optLong(key, 0)
-            }
-        } catch (_: Exception) {}
-        return scanSafTreeIncremental(treeUriStr, existingFiles)
-    }
-
-    private fun scanSafTreeIncremental(
-        treeUriStr: String,
-        existingFiles: Map<String, Long>,
-    ): String {
         if (treeUriStr.isBlank()) {
             val result = JSONObject()
             result.put("files", JSONArray())
@@ -1428,6 +1388,16 @@ class MainActivity: FlutterFragmentActivity() {
             return result.toString()
         }
 
+        val existingFiles = mutableMapOf<String, Long>()
+        try {
+            val obj = JSONObject(existingFilesJson)
+            val keys = obj.keys()
+            while (keys.hasNext()) {
+                val key = keys.next()
+                existingFiles[key] = obj.optLong(key, 0)
+            }
+        } catch (_: Exception) {}
+
         resetSafScanProgress()
         safScanCancel = false
         safScanActive = true
@@ -1966,54 +1936,9 @@ class MainActivity: FlutterFragmentActivity() {
     // We handle these URLs ourselves via receive_sharing_intent + ShareIntentService.
     override fun shouldHandleDeeplinking(): Boolean = false
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        handleExtensionOAuthIntent(intent)
-    }
-
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
         setIntent(intent)
-        handleExtensionOAuthIntent(intent)
-    }
-
-    /**
-     * Deliver Spotify (or other) OAuth authorization code to the extension runtime
-     * and run its token exchange (e.g. completeSpotifyLogin). State must be the extension id.
-     */
-    private fun handleExtensionOAuthIntent(intent: Intent?) {
-        val uri = intent?.data ?: return
-        if (!uri.scheme.equals("spotiflac", ignoreCase = true)) {
-            return
-        }
-        val host = (uri.host ?: "").lowercase(Locale.US)
-        val path = (uri.path ?: "").lowercase(Locale.US)
-        val isCallback =
-            host == "callback" ||
-                host == "spotify-callback" ||
-                path.contains("callback")
-        if (!isCallback) {
-            return
-        }
-        val code = uri.getQueryParameter("code")?.trim().orEmpty()
-        if (code.isEmpty()) {
-            return
-        }
-        val extId = uri.getQueryParameter("state")?.trim().orEmpty()
-        if (extId.isEmpty()) {
-            android.util.Log.w("SpotiFLAC", "Extension OAuth redirect missing state (extension id)")
-            return
-        }
-        intent.data = null
-        scope.launch(Dispatchers.IO) {
-            try {
-                Gobackend.setExtensionAuthCodeByID(extId, code)
-                val json = Gobackend.invokeExtensionActionJSON(extId, "completeSpotifyLogin")
-                android.util.Log.i("SpotiFLAC", "Extension OAuth complete for $extId: $json")
-            } catch (e: Exception) {
-                android.util.Log.w("SpotiFLAC", "Extension OAuth failed: ${e.message}")
-            }
-        }
     }
 
     override fun onDestroy() {
@@ -2029,7 +1954,6 @@ class MainActivity: FlutterFragmentActivity() {
 
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
-        Gobackend.setAppVersion(BuildConfig.VERSION_NAME)
 
         // Always-enabled back callback to ensure back presses reach Flutter.
         // Nested tab navigators can incorrectly set frameworkHandlesBack(false),
@@ -2103,7 +2027,7 @@ class MainActivity: FlutterFragmentActivity() {
                         "downloadByStrategy" -> {
                             val requestJson = call.arguments as String
                             val response = withContext(Dispatchers.IO) {
-                                SafDownloadHandler.handle(this@MainActivity, requestJson) { json ->
+                                handleSafDownload(requestJson) { json ->
                                     Gobackend.downloadByStrategy(json)
                                 }
                             }
@@ -2214,6 +2138,7 @@ class MainActivity: FlutterFragmentActivity() {
                                 result.error("saf_pending", "SAF picker already active", null)
                                 return@launch
                             }
+                            pendingSafTreeResult = result
                             val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
                             intent.addFlags(
                                 Intent.FLAG_GRANT_READ_URI_PERMISSION or
@@ -2221,24 +2146,7 @@ class MainActivity: FlutterFragmentActivity() {
                                     Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
                                     Intent.FLAG_GRANT_PREFIX_URI_PERMISSION
                             )
-                            val resolver = intent.resolveActivity(packageManager)
-                            if (resolver == null) {
-                                result.error("saf_unavailable", "No folder picker available on this device", null)
-                                return@launch
-                            }
-                            pendingSafTreeResult = result
-                            try {
-                                android.util.Log.i("SpotiFLAC", "Launching SAF picker via $resolver")
-                                safTreeLauncher.launch(intent)
-                            } catch (e: Exception) {
-                                pendingSafTreeResult = null
-                                android.util.Log.e("SpotiFLAC", "Failed to launch SAF picker: ${e.message}", e)
-                                result.error(
-                                    "saf_launch_failed",
-                                    e.message ?: "Failed to launch folder picker",
-                                    null
-                                )
-                            }
+                            safTreeLauncher.launch(intent)
                         }
                         "safExists" -> {
                             val uriStr = call.argument<String>("uri") ?: ""
@@ -2313,8 +2221,7 @@ class MainActivity: FlutterFragmentActivity() {
                                 val dir = ensureDocumentDir(Uri.parse(treeUriStr), relativeDir) ?: return@withContext null
                                 val existing = dir.findFile(fileName)
                                 val createdNew = existing == null
-                                val doc = createOrReuseDocumentFile(dir, mimeType, fileName)
-                                    ?: return@withContext null
+                                val doc = existing ?: dir.createFile(mimeType, fileName) ?: return@withContext null
                                 if (!writeUriFromPath(doc.uri, srcPath)) {
                                     if (createdNew) {
                                         doc.delete()
@@ -2477,41 +2384,6 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
-                        "rewriteSplitArtistTags" -> {
-                            val filePath = call.argument<String>("file_path") ?: ""
-                            val artist = call.argument<String>("artist") ?: ""
-                            val albumArtist = call.argument<String>("album_artist") ?: ""
-                            val response = withContext(Dispatchers.IO) {
-                                if (filePath.startsWith("content://")) {
-                                    val uri = Uri.parse(filePath)
-                                    val tempPath = copyUriToTemp(uri, ".flac")
-                                        ?: return@withContext errorJson("Failed to copy SAF file to temp")
-                                    try {
-                                        val raw = Gobackend.rewriteSplitArtistTagsExport(tempPath, artist, albumArtist)
-                                        val obj = JSONObject(raw)
-                                        if (!obj.optBoolean("success", false)) {
-                                            return@withContext raw
-                                        }
-
-                                        if (!writeUriFromPath(uri, tempPath)) {
-                                            return@withContext errorJson("Failed to write rewritten tags back to SAF file")
-                                        }
-
-                                        obj.put("file_path", filePath)
-                                        obj.toString()
-                                    } catch (e: Exception) {
-                                        errorJson("Failed to rewrite split artist tags in SAF file: ${e.message}")
-                                    } finally {
-                                        try {
-                                            File(tempPath).delete()
-                                        } catch (_: Exception) {}
-                                    }
-                                } else {
-                                    Gobackend.rewriteSplitArtistTagsExport(filePath, artist, albumArtist)
-                                }
-                            }
-                            result.success(response)
-                        }
                         "cleanupConnections" -> {
                             withContext(Dispatchers.IO) {
                                 Gobackend.cleanupConnections()
@@ -2644,27 +2516,12 @@ class MainActivity: FlutterFragmentActivity() {
                             val spotifyId = call.argument<String>("spotify_id") ?: ""
                             val durationMs = call.argument<Number>("duration_ms")?.toLong() ?: 0L
                             val outputPath = call.argument<String>("output_path") ?: ""
-                            val rawAudioFilePath = call.argument<String>("audio_file_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                var safAudioTemp: String? = null
                                 try {
-                                    // Resolve SAF content:// URI to a temp file the Go backend can read
-                                    val audioFilePath = if (rawAudioFilePath.startsWith("content://")) {
-                                        val uri = Uri.parse(rawAudioFilePath)
-                                        val tempPath = copyUriToTemp(uri)
-                                        safAudioTemp = tempPath
-                                        tempPath ?: ""
-                                    } else {
-                                        rawAudioFilePath
-                                    }
-                                    Gobackend.fetchAndSaveLyrics(trackName, artistName, spotifyId, durationMs, outputPath, audioFilePath)
+                                    Gobackend.fetchAndSaveLyrics(trackName, artistName, spotifyId, durationMs, outputPath)
                                     """{"success":true}"""
                                 } catch (e: Exception) {
                                     """{"success":false,"error":"${e.message?.replace("\"", "'")}"}"""
-                                } finally {
-                                    if (safAudioTemp != null) {
-                                        try { File(safAudioTemp).delete() } catch (_: Exception) {}
-                                    }
                                 }
                             }
                             result.success(response)
@@ -2784,47 +2641,15 @@ class MainActivity: FlutterFragmentActivity() {
                         "updateDownloadServiceProgress" -> {
                             val trackName = call.argument<String>("track_name") ?: ""
                             val artistName = call.argument<String>("artist_name") ?: ""
-                            val progress = (call.argument<Number>("progress") ?: 0).toLong()
-                            val total = (call.argument<Number>("total") ?: 0).toLong()
-                            val queueCount = (call.argument<Number>("queue_count") ?: 0).toInt()
-                            val status = call.argument<String>("status") ?: "downloading"
-                            DownloadService.updateProgress(this@MainActivity, trackName, artistName, progress, total, queueCount, status)
+                            val progress = call.argument<Long>("progress") ?: 0L
+                            val total = call.argument<Long>("total") ?: 0L
+                            val queueCount = call.argument<Int>("queue_count") ?: 0
+                            DownloadService.updateProgress(this@MainActivity, trackName, artistName, progress, total, queueCount)
                             result.success(null)
                         }
                         "isDownloadServiceRunning" -> {
                             result.success(DownloadService.isServiceRunning())
                         }
-                        "startNativeDownloadWorker" -> {
-                            val requestsJson = call.argument<String>("requests_json") ?: "[]"
-                            val settingsJson = call.argument<String>("settings_json") ?: "{}"
-                            val requestsPath = call.argument<String>("requests_path") ?: ""
-                            val settingsPath = call.argument<String>("settings_path") ?: ""
-                            if (requestsPath.isNotBlank()) {
-                                DownloadService.startNativeQueueFromFiles(
-                                    this@MainActivity,
-                                    requestsPath,
-                                    settingsPath
-                                )
-                            } else {
-                                DownloadService.startNativeQueue(this@MainActivity, requestsJson, settingsJson)
-                            }
-                            result.success(null)
-                        }
-                        "pauseNativeDownloadWorker" -> {
-                            DownloadService.pauseNativeQueue(this@MainActivity)
-                            result.success(null)
-                        }
-                        "resumeNativeDownloadWorker" -> {
-                            DownloadService.resumeNativeQueue(this@MainActivity)
-                            result.success(null)
-                        }
-                        "cancelNativeDownloadWorker" -> {
-                            DownloadService.cancelNativeQueue(this@MainActivity)
-                            result.success(null)
-                        }
-                        "getNativeDownloadWorkerSnapshot" -> {
-                            result.success(parseJsonPayload(DownloadService.getNativeWorkerSnapshot(this@MainActivity)))
-                        }
                         "preWarmTrackCache" -> {
                             val tracksJson = call.argument<String>("tracks") ?: "[]"
                             withContext(Dispatchers.IO) {
@@ -2844,6 +2669,36 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(null)
                         }
+                        "searchDeezerAll" -> {
+                            val query = call.argument<String>("query") ?: ""
+                            val trackLimit = call.argument<Int>("track_limit") ?: 15
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 2
+                            val filter = call.argument<String>("filter") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchDeezerAll(query, trackLimit.toLong(), artistLimit.toLong(), filter)
+                            }
+                            result.success(response)
+                        }
+                        "searchTidalAll" -> {
+                            val query = call.argument<String>("query") ?: ""
+                            val trackLimit = call.argument<Int>("track_limit") ?: 15
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 2
+                            val filter = call.argument<String>("filter") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchTidalAll(query, trackLimit.toLong(), artistLimit.toLong(), filter)
+                            }
+                            result.success(response)
+                        }
+                        "searchQobuzAll" -> {
+                            val query = call.argument<String>("query") ?: ""
+                            val trackLimit = call.argument<Int>("track_limit") ?: 15
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 2
+                            val filter = call.argument<String>("filter") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchQobuzAll(query, trackLimit.toLong(), artistLimit.toLong(), filter)
+                            }
+                            result.success(response)
+                        }
                         "getDeezerRelatedArtists" -> {
                             val artistId = call.argument<String>("artist_id") ?: ""
                             val limit = call.argument<Int>("limit") ?: 12
@@ -2852,20 +2707,62 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
-                        "getProviderMetadata" -> {
-                            val providerId = call.argument<String>("provider_id") ?: ""
+                        "getDeezerMetadata" -> {
                             val resourceType = call.argument<String>("resource_type") ?: ""
                             val resourceId = call.argument<String>("resource_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.getProviderMetadataJSON(providerId, resourceType, resourceId)
+                                Gobackend.getDeezerMetadata(resourceType, resourceId)
+                            }
+                            result.success(response)
+                        }
+                        "getQobuzMetadata" -> {
+                            val resourceType = call.argument<String>("resource_type") ?: ""
+                            val resourceId = call.argument<String>("resource_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getQobuzMetadata(resourceType, resourceId)
+                            }
+                            result.success(response)
+                        }
+                        "getTidalMetadata" -> {
+                            val resourceType = call.argument<String>("resource_type") ?: ""
+                            val resourceId = call.argument<String>("resource_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getTidalMetadata(resourceType, resourceId)
+                            }
+                            result.success(response)
+                        }
+                        "parseDeezerUrl" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.parseDeezerURLExport(url)
+                            }
+                            result.success(response)
+                        }
+                        "parseQobuzUrl" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.parseQobuzURLExport(url)
+                            }
+                            result.success(response)
+                        }
+                        "parseTidalUrl" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.parseTidalURLExport(url)
+                            }
+                            result.success(response)
+                        }
+                        "convertTidalToSpotifyDeezer" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.convertTidalToSpotifyDeezer(url)
                             }
                             result.success(response)
                         }
                         "searchDeezerByISRC" -> {
                             val isrc = call.argument<String>("isrc") ?: ""
-                            val itemId = call.argument<String>("item_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.searchDeezerByISRCForItemID(isrc, itemId)
+                                Gobackend.searchDeezerByISRC(isrc)
                             }
                             result.success(response)
                         }
@@ -3023,13 +2920,6 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
-                        "setDownloadFallbackExtensionIds" -> {
-                            val extensionIdsJson = call.argument<String>("extension_ids") ?: ""
-                            withContext(Dispatchers.IO) {
-                                Gobackend.setExtensionFallbackProviderIDsJSON(extensionIdsJson)
-                            }
-                            result.success(null)
-                        }
                         "setMetadataProviderPriority" -> {
                             val priorityJson = call.argument<String>("priority") ?: "[]"
                             withContext(Dispatchers.IO) {
@@ -3050,13 +2940,6 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
-                        "checkExtensionHealth" -> {
-                            val extensionId = call.argument<String>("extension_id") ?: ""
-                            val response = withContext(Dispatchers.IO) {
-                                Gobackend.checkExtensionHealthJSON(extensionId)
-                            }
-                            result.success(response)
-                        }
                         "setExtensionSettings" -> {
                             val extensionId = call.argument<String>("extension_id") ?: ""
                             val settingsJson = call.argument<String>("settings") ?: "{}"
@@ -3184,19 +3067,11 @@ class MainActivity: FlutterFragmentActivity() {
                             val extensionId = call.argument<String>("extension_id") ?: ""
                             val query = call.argument<String>("query") ?: ""
                             val optionsJson = call.argument<String>("options") ?: ""
-                            val requestId = call.argument<String>("request_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.customSearchWithExtensionJSONWithRequestID(extensionId, query, optionsJson, requestId)
+                                Gobackend.customSearchWithExtensionJSON(extensionId, query, optionsJson)
                             }
                             result.success(response)
                         }
-                        "cancelExtensionRequest" -> {
-                            val requestId = call.argument<String>("request_id") ?: ""
-                            withContext(Dispatchers.IO) {
-                                Gobackend.cancelExtensionRequestJSON(requestId)
-                            }
-                            result.success(null)
-                        }
                         "getSearchProviders" -> {
                             val response = withContext(Dispatchers.IO) {
                                 Gobackend.getSearchProvidersJSON()
@@ -3223,6 +3098,30 @@ class MainActivity: FlutterFragmentActivity() {
                             }
                             result.success(response)
                         }
+                        "getAlbumWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val albumId = call.argument<String>("album_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getAlbumWithExtensionJSON(extensionId, albumId)
+                            }
+                            result.success(response)
+                        }
+                        "getPlaylistWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val playlistId = call.argument<String>("playlist_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getPlaylistWithExtensionJSON(extensionId, playlistId)
+                            }
+                            result.success(response)
+                        }
+                        "getArtistWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val artistId = call.argument<String>("artist_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getArtistWithExtensionJSON(extensionId, artistId)
+                            }
+                            result.success(response)
+                        }
                         "runPostProcessing" -> {
                             val filePath = call.argument<String>("file_path") ?: ""
                             val metadataJson = call.argument<String>("metadata") ?: ""
@@ -3329,9 +3228,8 @@ class MainActivity: FlutterFragmentActivity() {
                         }
                         "getExtensionHomeFeed" -> {
                             val extensionId = call.argument<String>("extension_id") ?: ""
-                            val requestId = call.argument<String>("request_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.getExtensionHomeFeedJSONWithRequestID(extensionId, requestId)
+                                Gobackend.getExtensionHomeFeedJSON(extensionId)
                             }
                             result.success(response)
                         }
@@ -3353,7 +3251,7 @@ class MainActivity: FlutterFragmentActivity() {
                             val folderPath = call.argument<String>("folder_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                bridgeJsonResult(Gobackend.scanLibraryFolderJSON(folderPath))
+                                Gobackend.scanLibraryFolderJSON(folderPath)
                             }
                             result.success(response)
                         }
@@ -3362,9 +3260,7 @@ class MainActivity: FlutterFragmentActivity() {
                             val existingFiles = call.argument<String>("existing_files") ?: "{}"
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                bridgeJsonResult(
-                                    Gobackend.scanLibraryFolderIncrementalJSON(folderPath, existingFiles)
-                                )
+                                Gobackend.scanLibraryFolderIncrementalJSON(folderPath, existingFiles)
                             }
                             result.success(response)
                         }
@@ -3373,11 +3269,9 @@ class MainActivity: FlutterFragmentActivity() {
                             val snapshotPath = call.argument<String>("snapshot_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                bridgeJsonResult(
-                                    Gobackend.scanLibraryFolderIncrementalFromSnapshotJSON(
-                                        folderPath,
-                                        snapshotPath,
-                                    )
+                                Gobackend.scanLibraryFolderIncrementalFromSnapshotJSON(
+                                    folderPath,
+                                    snapshotPath,
                                 )
                             }
                             result.success(response)
@@ -3385,7 +3279,7 @@ class MainActivity: FlutterFragmentActivity() {
                         "scanSafTree" -> {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                bridgeJsonResult(scanSafTree(treeUri))
+                                scanSafTree(treeUri)
                             }
                             result.success(response)
                         }
@@ -3393,7 +3287,7 @@ class MainActivity: FlutterFragmentActivity() {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val existingFiles = call.argument<String>("existing_files") ?: "{}"
                             val response = withContext(Dispatchers.IO) {
-                                bridgeJsonResult(scanSafTreeIncremental(treeUri, existingFiles))
+                                scanSafTreeIncremental(treeUri, existingFiles)
                             }
                             result.success(response)
                         }
@@ -3401,9 +3295,9 @@ class MainActivity: FlutterFragmentActivity() {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val snapshotPath = call.argument<String>("snapshot_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                val existingFiles =
-                                    loadExistingFilesFromSnapshot(snapshotPath)
-                                bridgeJsonResult(scanSafTreeIncremental(treeUri, existingFiles))
+                                val existingFilesJson =
+                                    loadExistingFilesJsonFromSnapshot(snapshotPath)
+                                scanSafTreeIncremental(treeUri, existingFilesJson)
                             }
                             result.success(response)
                         }

android/app/src/main/kotlin/com/zarz/spotiflac/SafDownloadHandler.kt

@@ -1,477 +0,0 @@
-package com.zarz.spotiflac
-
-import android.content.Context
-import android.net.Uri
-import android.util.Log
-import androidx.documentfile.provider.DocumentFile
-import org.json.JSONObject
-import java.io.File
-import java.util.Locale
-
-/**
- * Shared SAF download wrapper for foreground activity calls and service-owned
- * native workers.
- */
-object SafDownloadHandler {
-    private val safDirLock = Any()
-    private const val MAX_SAF_DISPLAY_NAME_UTF8_BYTES = 180
-
-    fun handle(context: Context, requestJson: String, downloader: (String) -> String): String {
-        val req = JSONObject(requestJson)
-        val storageMode = req.optString("storage_mode", "")
-        val treeUriStr = req.optString("saf_tree_uri", "")
-        if (storageMode != "saf" || treeUriStr.isBlank()) {
-            return downloader(requestJson)
-        }
-
-        val treeUri = Uri.parse(treeUriStr)
-        val relativeDir = sanitizeRelativeDir(req.optString("saf_relative_dir", ""))
-        val outputExt = normalizeExt(req.optString("saf_output_ext", ""))
-        val mimeType = mimeTypeForExt(outputExt)
-        val fileName = buildSafFileName(req, outputExt)
-        val deferSafPublish = req.optBoolean("defer_saf_publish", false)
-        val useStagedOutput = req.optBoolean("stage_saf_output", false) && !deferSafPublish
-        val stagedFileName = if (useStagedOutput) buildStagedSafFileName(fileName, outputExt) else fileName
-        val staleStagedFileName = buildStagedSafFileName(fileName, outputExt)
-
-        val existingDir = findDocumentDir(context, treeUri, relativeDir)
-        if (existingDir != null) {
-            val existing = existingDir.findFile(fileName)
-            if (existing != null && existing.isFile && existing.length() > 0) {
-                if (useStagedOutput || deferSafPublish) {
-                    existingDir.findFile(staleStagedFileName)?.delete()
-                }
-                val obj = JSONObject()
-                obj.put("success", true)
-                obj.put("message", "File already exists")
-                obj.put("file_path", existing.uri.toString())
-                obj.put("file_name", existing.name ?: fileName)
-                obj.put("already_exists", true)
-                return obj.toString()
-            }
-        }
-
-        val targetDir = ensureDocumentDir(context, treeUri, relativeDir)
-            ?: return errorJson("Failed to access SAF directory")
-
-        if (deferSafPublish) {
-            targetDir.findFile(staleStagedFileName)?.delete()
-            val workingExt = outputExt.ifBlank { ".tmp" }
-            val workingFile = File.createTempFile("native_saf_work_", workingExt, context.cacheDir)
-            Log.i("SpotiFLAC", "SAF deferred native output: target=$fileName working=${workingFile.name}")
-            return try {
-                req.put("output_path", workingFile.absolutePath)
-                req.put("output_ext", outputExt)
-                req.remove("output_fd")
-                val response = downloader(req.toString())
-                val respObj = JSONObject(response)
-                if (respObj.optBoolean("success", false)) {
-                    val reportedPath = respObj.optString("file_path", "").trim()
-                    if (reportedPath.isEmpty() || reportedPath.startsWith("/proc/self/fd/")) {
-                        respObj.put("file_path", workingFile.absolutePath)
-                    } else if (reportedPath != workingFile.absolutePath) {
-                        workingFile.delete()
-                    }
-                    respObj.put("file_name", respObj.optString("file_name", "").ifBlank { fileName })
-                    respObj.put("saf_deferred_publish", true)
-                    respObj.put("saf_final_file_name", fileName)
-                    respObj.put("saf_relative_dir", relativeDir)
-                    respObj.put("saf_tree_uri", treeUriStr)
-                    respObj.put("saf_output_ext", outputExt)
-                    respObj.put("saf_final_mime_type", mimeType)
-                } else {
-                    workingFile.delete()
-                }
-                respObj.toString()
-            } catch (e: Exception) {
-                workingFile.delete()
-                errorJson("SAF deferred download failed: ${e.message}")
-            }
-        }
-
-        var document = createOrReuseDocumentFile(targetDir, mimeType, stagedFileName)
-            ?: return errorJson("Failed to create SAF file")
-
-        val pfd = context.contentResolver.openFileDescriptor(document.uri, "rw")
-            ?: return errorJson("Failed to open SAF file")
-
-        var detachedFd: Int? = null
-        try {
-            detachedFd = pfd.detachFd()
-            req.put("output_path", "")
-            req.put("output_fd", detachedFd)
-            req.put("output_ext", outputExt)
-            val response = downloader(req.toString())
-            val respObj = JSONObject(response)
-            if (respObj.optBoolean("success", false)) {
-                val goFilePath = respObj.optString("file_path", "")
-                if (goFilePath.isNotEmpty() &&
-                    !goFilePath.startsWith("content://") &&
-                    !goFilePath.startsWith("/proc/self/fd/")
-                ) {
-                    try {
-                        val srcFile = File(goFilePath)
-                        if (!srcFile.exists() || srcFile.length() <= 0) {
-                            throw IllegalStateException("extension output missing or empty: $goFilePath")
-                        }
-                        val actualExt = normalizeExt(srcFile.extension)
-                        if (actualExt.isNotBlank()) {
-                            respObj.put("actual_extension", actualExt)
-                        }
-                        if (actualExt.isNotBlank() && actualExt != outputExt) {
-                            val actualFileName = buildSafFileName(req, actualExt)
-                            val actualStagedFileName = if (useStagedOutput) {
-                                buildStagedSafFileName(actualFileName, actualExt)
-                            } else {
-                                actualFileName
-                            }
-                            val actualMimeType = mimeTypeForExt(actualExt)
-                            val replacement = createOrReuseDocumentFile(
-                                targetDir,
-                                actualMimeType,
-                                actualStagedFileName
-                            ) ?: throw IllegalStateException(
-                                "failed to create SAF output with actual extension"
-                            )
-                            if (replacement.uri != document.uri) {
-                                document.delete()
-                                document = replacement
-                            }
-                        }
-                        context.contentResolver.openOutputStream(document.uri, "wt")?.use { output ->
-                            srcFile.inputStream().use { input ->
-                                input.copyTo(output)
-                            }
-                        } ?: throw IllegalStateException("failed to open SAF output stream")
-                        srcFile.delete()
-                    } catch (e: Exception) {
-                        document.delete()
-                        android.util.Log.w(
-                            "SpotiFLAC",
-                            "Failed to copy extension output to SAF: ${e.message}"
-                        )
-                        return errorJson("Failed to copy extension output to SAF: ${e.message}")
-                    }
-                }
-                respObj.put("file_path", document.uri.toString())
-                respObj.put("file_name", document.name ?: fileName)
-                if (useStagedOutput) {
-                    respObj.put("saf_staged_output", true)
-                    respObj.put("saf_staged_file_name", document.name ?: stagedFileName)
-                }
-            } else {
-                document.delete()
-            }
-            return respObj.toString()
-        } catch (e: Exception) {
-            document.delete()
-            return errorJson("SAF download failed: ${e.message}")
-        } finally {
-            if (detachedFd == null) {
-                try {
-                    pfd.close()
-                } catch (_: Exception) {
-                }
-            }
-        }
-    }
-
-    fun copyContentUriToTemp(context: Context, uriStr: String): String? {
-        return try {
-            val uri = Uri.parse(uriStr)
-            val extension = DocumentFile.fromSingleUri(context, uri)
-                ?.name
-                ?.substringAfterLast('.', "")
-                ?.takeIf { it.isNotBlank() }
-                ?.let { ".$it" }
-                ?: ".tmp"
-            val temp = File.createTempFile("native_saf_", extension, context.cacheDir)
-            context.contentResolver.openInputStream(uri)?.use { input ->
-                temp.outputStream().use { output ->
-                    input.copyTo(output)
-                }
-            } ?: return null
-            temp.absolutePath
-        } catch (e: Exception) {
-            android.util.Log.w("SpotiFLAC", "Failed to copy SAF URI to temp: ${e.message}")
-            null
-        }
-    }
-
-    fun writeFileToSaf(
-        context: Context,
-        treeUriStr: String,
-        relativeDir: String,
-        fileName: String,
-        mimeType: String,
-        srcPath: String
-    ): String? {
-        var stagedDocument: DocumentFile? = null
-        return try {
-            val treeUri = Uri.parse(treeUriStr)
-            val targetDir = ensureDocumentDir(context, treeUri, relativeDir) ?: return null
-            val finalName = sanitizeFilename(fileName)
-            val ext = normalizeExt(finalName.substringAfterLast('.', ""))
-            val stagedName = buildStagedSafFileName(finalName, ext)
-            val document = createOrReuseDocumentFile(targetDir, mimeType, stagedName)
-                ?: return null
-            stagedDocument = document
-            val outputStream = context.contentResolver.openOutputStream(document.uri, "wt")
-            if (outputStream == null) {
-                document.delete()
-                stagedDocument = null
-                return null
-            }
-            outputStream.use { output ->
-                File(srcPath).inputStream().use { input ->
-                    input.copyTo(output)
-                }
-            }
-
-            val existingFinal = targetDir.findFile(finalName)
-            if (existingFinal != null && existingFinal.uri != document.uri) {
-                existingFinal.delete()
-            }
-            if (!document.renameTo(finalName)) {
-                document.delete()
-                return null
-            }
-            stagedDocument = null
-            targetDir.findFile(finalName)?.uri?.toString() ?: document.uri.toString()
-        } catch (e: Exception) {
-            stagedDocument?.delete()
-            android.util.Log.w("SpotiFLAC", "Failed to write file to SAF: ${e.message}")
-            null
-        }
-    }
-
-    fun deleteContentUri(context: Context, uriStr: String): Boolean {
-        return try {
-            DocumentFile.fromSingleUri(context, Uri.parse(uriStr))?.delete() == true
-        } catch (_: Exception) {
-            false
-        }
-    }
-
-    private fun normalizeExt(ext: String?): String {
-        if (ext.isNullOrBlank()) return ""
-        return if (ext.startsWith(".")) {
-            ext.lowercase(Locale.ROOT)
-        } else {
-            ".${ext.lowercase(Locale.ROOT)}"
-        }
-    }
-
-    private fun mimeTypeForExt(ext: String?): String {
-        return when (normalizeExt(ext)) {
-            ".m4a", ".mp4" -> "audio/mp4"
-            ".mp3" -> "audio/mpeg"
-            ".opus" -> "audio/ogg"
-            ".flac" -> "audio/flac"
-            ".lrc" -> "application/octet-stream"
-            else -> "application/octet-stream"
-        }
-    }
-
-    private fun forceFilenameExt(name: String, outputExt: String): String {
-        val normalizedExt = normalizeExt(outputExt)
-        if (normalizedExt.isBlank()) return sanitizeFilename(name)
-
-        val safeName = sanitizeFilename(name)
-        val lower = safeName.lowercase(Locale.ROOT)
-        val knownExts = listOf(".flac", ".m4a", ".mp4", ".mp3", ".opus", ".lrc")
-        for (knownExt in knownExts) {
-            if (lower.endsWith(knownExt)) {
-                return safeName.dropLast(knownExt.length) + normalizedExt
-            }
-        }
-        return safeName + normalizedExt
-    }
-
-    private fun buildStagedSafFileName(fileName: String, outputExt: String): String {
-        val safeName = sanitizeFilename(fileName)
-        val ext = normalizeExt(outputExt)
-        if (ext.isNotBlank() && safeName.lowercase(Locale.ROOT).endsWith(ext)) {
-            return safeName.dropLast(ext.length).trimEnd('.', ' ') + ".partial$ext"
-        }
-
-        val dot = safeName.lastIndexOf('.')
-        if (dot > 0 && dot < safeName.lastIndex) {
-            return safeName.substring(0, dot).trimEnd('.', ' ') +
-                ".partial" +
-                safeName.substring(dot)
-        }
-        return "$safeName.partial"
-    }
-
-    private fun sanitizeFilename(name: String): String {
-        var sanitized = name
-            .replace("/", " ")
-            .replace(Regex("[\\\\:*?\"<>|]"), " ")
-            .filter { ch ->
-                val code = ch.code
-                !((code < 0x20 && ch != '\t' && ch != '\n' && ch != '\r') ||
-                    code == 0x7F ||
-                    (Character.isISOControl(ch) && ch != '\t' && ch != '\n' && ch != '\r'))
-            }
-            .trim()
-            .trim('.', ' ')
-
-        sanitized = sanitized
-            .replace(Regex("\\s+"), " ")
-            .replace(Regex("_+"), "_")
-            .trim('_', ' ')
-
-        sanitized = truncateSafDisplayName(sanitized, MAX_SAF_DISPLAY_NAME_UTF8_BYTES)
-        sanitized = sanitized.trim().trim('.', ' ').trim('_', ' ')
-        return if (sanitized.isBlank()) "Unknown" else sanitized
-    }
-
-    private fun truncateSafDisplayName(name: String, maxBytes: Int): String {
-        if (maxBytes <= 0 || name.toByteArray(Charsets.UTF_8).size <= maxBytes) return name
-
-        val dotIndex = name.lastIndexOf('.')
-        val ext = if (
-            dotIndex > 0 &&
-            dotIndex < name.length - 1 &&
-            name.length - dotIndex <= 10
-        ) {
-            name.substring(dotIndex)
-        } else {
-            ""
-        }
-        val stem = if (ext.isNotEmpty()) name.substring(0, dotIndex) else name
-        val maxStemBytes = (maxBytes - ext.toByteArray(Charsets.UTF_8).size).coerceAtLeast(1)
-        return truncateUtf8Bytes(stem, maxStemBytes).trim().trim('.', ' ').trim('_', ' ') + ext
-    }
-
-    private fun truncateUtf8Bytes(value: String, maxBytes: Int): String {
-        if (maxBytes <= 0 || value.toByteArray(Charsets.UTF_8).size <= maxBytes) return value
-
-        val builder = StringBuilder()
-        var usedBytes = 0
-        var index = 0
-        while (index < value.length) {
-            val codePoint = value.codePointAt(index)
-            val char = String(Character.toChars(codePoint))
-            val charBytes = char.toByteArray(Charsets.UTF_8).size
-            if (usedBytes + charBytes > maxBytes) break
-            builder.append(char)
-            usedBytes += charBytes
-            index += Character.charCount(codePoint)
-        }
-        return builder.toString()
-    }
-
-    private fun sanitizeRelativeDir(relativeDir: String): String {
-        if (relativeDir.isBlank()) return ""
-        return relativeDir
-            .split("/")
-            .map { sanitizeFilename(it) }
-            .filter { it.isNotBlank() && it != "." && it != ".." }
-            .joinToString("/")
-    }
-
-    private fun ensureDocumentDir(
-        context: Context,
-        treeUri: Uri,
-        relativeDir: String
-    ): DocumentFile? {
-        val safeRelativeDir = sanitizeRelativeDir(relativeDir)
-        if (safeRelativeDir.isBlank()) {
-            return DocumentFile.fromTreeUri(context, treeUri)
-        }
-
-        synchronized(safDirLock) {
-            var current = DocumentFile.fromTreeUri(context, treeUri) ?: return null
-            val parts = safeRelativeDir.split("/").filter { it.isNotBlank() }
-            for (part in parts) {
-                val existing = current.findFile(part)
-                current = if (existing != null && existing.isDirectory) {
-                    existing
-                } else {
-                    val created = current.createDirectory(part) ?: return null
-                    val createdName = created.name ?: part
-                    if (createdName != part) {
-                        created.delete()
-                        current.findFile(part) ?: return null
-                    } else {
-                        created
-                    }
-                }
-            }
-            return current
-        }
-    }
-
-    private fun findDocumentDir(
-        context: Context,
-        treeUri: Uri,
-        relativeDir: String
-    ): DocumentFile? {
-        var current = DocumentFile.fromTreeUri(context, treeUri) ?: return null
-        val safeRelativeDir = sanitizeRelativeDir(relativeDir)
-        if (safeRelativeDir.isBlank()) return current
-
-        val parts = safeRelativeDir.split("/").filter { it.isNotBlank() }
-        for (part in parts) {
-            val existing = current.findFile(part)
-            if (existing == null || !existing.isDirectory) return null
-            current = existing
-        }
-        return current
-    }
-
-    private fun createOrReuseDocumentFile(
-        parent: DocumentFile,
-        mimeType: String,
-        fileName: String
-    ): DocumentFile? {
-        val safeFileName = sanitizeFilename(fileName)
-        if (safeFileName.isBlank()) return null
-
-        synchronized(safDirLock) {
-            val existing = parent.findFile(safeFileName)
-            if (existing != null && existing.isFile) {
-                return existing
-            }
-
-            val created = parent.createFile(mimeType, safeFileName) ?: return null
-            val createdName = created.name ?: safeFileName
-            if (createdName == safeFileName) {
-                return created
-            }
-
-            val winner = parent.findFile(safeFileName)
-            if (winner != null && winner.isFile) {
-                if (winner.uri != created.uri) {
-                    try {
-                        created.delete()
-                    } catch (_: Exception) {
-                    }
-                }
-                return winner
-            }
-
-            return created
-        }
-    }
-
-    private fun buildSafFileName(req: JSONObject, outputExt: String): String {
-        val provided = req.optString("saf_file_name", "")
-        if (provided.isNotBlank()) return forceFilenameExt(provided, outputExt)
-
-        val trackName = req.optString("track_name", "track")
-        val artistName = req.optString("artist_name", "")
-        val baseName = if (artistName.isNotBlank()) "$artistName - $trackName" else trackName
-        return forceFilenameExt(baseName, outputExt)
-    }
-
-    private fun errorJson(message: String): String {
-        val obj = JSONObject()
-        obj.put("success", false)
-        obj.put("error", message)
-        obj.put("message", message)
-        return obj.toString()
-    }
-}

android/app/src/main/res/drawable-v21/launch_background.xml

@@ -1,4 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
 </layer-list>

android/app/src/main/res/drawable/launch_background.xml

@@ -1,4 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:drawable="@android:color/white" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
 </layer-list>

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -6,9 +6,4 @@
           android:drawable="@drawable/ic_launcher_foreground"
           android:inset="16%" />
   </foreground>
-  <monochrome>
-      <inset
-          android:drawable="@drawable/ic_launcher_monochrome"
-          android:inset="16%" />
-  </monochrome>
 </adaptive-icon>

android/app/src/main/res/values-night/styles.xml

@@ -1,8 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
     <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             the Flutter engine draws its first frame -->
         <item name="android:windowBackground">@drawable/launch_background</item>
     </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
     <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
         <item name="android:windowBackground">?android:colorBackground</item>
     </style>

android/app/src/main/res/values/styles.xml

@@ -1,8 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
     <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             the Flutter engine draws its first frame -->
         <item name="android:windowBackground">@drawable/launch_background</item>
     </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
     <style name="NormalTheme" parent="@android:style/Theme.Light.NoTitleBar">
         <item name="android:windowBackground">?android:colorBackground</item>
     </style>

android/gradle.properties

@@ -1,2 +1,2 @@
-org.gradle.jvmargs=-Xmx2g -XX:MaxMetaspaceSize=512m -XX:ReservedCodeCacheSize=256m -XX:+HeapDumpOnOutOfMemoryError
+org.gradle.jvmargs=-Xmx4G -XX:MaxMetaspaceSize=2G -XX:ReservedCodeCacheSize=256m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true

android/gradle/wrapper/gradle-wrapper.properties

@@ -1,9 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.0-all.zip
-networkTimeout=10000
-retries=0
-retryBackOffMs=500
-validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-all.zip

android/settings.gradle.kts

@@ -20,7 +20,7 @@ pluginManagement {
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.13.2" apply false
-    id("org.jetbrains.kotlin.android") version "2.3.21" apply false
+    id("org.jetbrains.kotlin.android") version "2.2.21" apply false
 }
 
 include(":app")

apps.json

@@ -1,18 +1,18 @@
 {
-  "name": "SpotiFLAC Mobile Source",
+  "name": "SpotiFLAC Source",
   "identifier": "com.zarzet.spotiflac.source",
   "subtitle": "FLAC Downloader for iOS",
   "apps": [
     {
-      "name": "SpotiFLAC Mobile",
+      "name": "SpotiFLAC",
       "bundleIdentifier": "com.zarzet.spotiflac",
       "developerName": "zarzet",
-      "version": "4.5.0",
-      "versionDate": "2026-05-06",
-      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v4.5.0/SpotiFLAC-v4.5.0-ios-unsigned.ipa",
-      "localizedDescription": "SpotiFLAC Mobile is written in Flutter. Download tracks in true FLAC from Tidal, Qobuz, & Amazon Music.",
+      "version": "3.9.0",
+      "versionDate": "2026-03-25",
+      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v3.9.0/SpotiFLAC-v3.9.0-ios-unsigned.ipa",
+      "localizedDescription": "Mobile version of SpotiFLAC written in Flutter. Download Tracks in true FLAC from Tidal, Qobuz, & Amazon Music.",
       "iconURL": "https://raw.githubusercontent.com/zarzet/SpotiFLAC-Mobile/main/assets/images/logo.png",
-      "size": 37191956
+      "size": 34477323
     }
   ]
 }

crowdin.yml

@@ -6,7 +6,6 @@ files:
         # Short codes for single-variant languages
         de: de
         es: es
-        es-ES: es_ES
         fr: fr
         hi: hi
         id: id
@@ -14,11 +13,7 @@ files:
         ko: ko
         nl: nl
         pt: pt
-        pt-PT: pt_PT
         ru: ru
-        tr: tr
-        uk: uk
-        zh: zh
         # Full codes for Chinese variants
         zh-CN: zh_CN
         zh-TW: zh_TW

go_backend/ape_tags.go

@@ -1,607 +0,0 @@
-package gobackend
-
-import (
-	"encoding/binary"
-	"fmt"
-	"io"
-	"os"
-	"strings"
-)
-
-// APEv2 tag format constants.
-const (
-	apeTagPreamble     = "APETAGEX"
-	apeTagHeaderSize   = 32
-	apeTagVersion2     = 2000
-	apeTagFlagHeader   = 1 << 29 // bit 29: this is the header, not the footer
-	apeTagFlagReadOnly = 1 << 0
-	// Item flags: bits 1-2 encode content type
-	apeItemFlagUTF8   = 0 << 1 // 00: UTF-8 text
-	apeItemFlagBinary = 1 << 1 // 01: binary data
-	apeItemFlagLink   = 2 << 1 // 10: external link
-)
-
-// APETagItem represents a single key-value item in an APEv2 tag.
-type APETagItem struct {
-	Key   string
-	Value string
-	Flags uint32
-}
-
-// APETag represents a complete APEv2 tag block.
-type APETag struct {
-	Version  uint32
-	Items    []APETagItem
-	ReadOnly bool
-}
-
-// ReadAPETags reads APEv2 tags from a file.
-// APEv2 tags are typically appended at the end of the file.
-// The layout is: [audio data] [APEv2 header (optional)] [items...] [APEv2 footer]
-// We locate the footer first (last 32 bytes), then read the tag block.
-func ReadAPETags(filePath string) (*APETag, error) {
-	f, err := os.Open(filePath)
-	if err != nil {
-		return nil, fmt.Errorf("failed to open file: %w", err)
-	}
-	defer f.Close()
-
-	fi, err := f.Stat()
-	if err != nil {
-		return nil, fmt.Errorf("failed to stat file: %w", err)
-	}
-	fileSize := fi.Size()
-
-	if fileSize < apeTagHeaderSize {
-		return nil, fmt.Errorf("file too small for APE tag")
-	}
-
-	// The footer is the last 32 bytes before any ID3v1 tag (128 bytes).
-	tag, err := readAPETagAtOffset(f, fileSize, fileSize-apeTagHeaderSize)
-	if err == nil {
-		return tag, nil
-	}
-
-	// Retry: skip ID3v1 tag (128 bytes) if present
-	if fileSize > apeTagHeaderSize+128 {
-		tag, err = readAPETagAtOffset(f, fileSize, fileSize-apeTagHeaderSize-128)
-		if err == nil {
-			return tag, nil
-		}
-	}
-
-	return nil, fmt.Errorf("no APEv2 tag found")
-}
-
-func readAPETagAtOffset(f *os.File, fileSize, footerOffset int64) (*APETag, error) {
-	if footerOffset < 0 || footerOffset+apeTagHeaderSize > fileSize {
-		return nil, fmt.Errorf("invalid footer offset")
-	}
-
-	footer := make([]byte, apeTagHeaderSize)
-	if _, err := f.ReadAt(footer, footerOffset); err != nil {
-		return nil, fmt.Errorf("failed to read APE footer: %w", err)
-	}
-
-	if string(footer[0:8]) != apeTagPreamble {
-		return nil, fmt.Errorf("APE preamble not found")
-	}
-
-	version := binary.LittleEndian.Uint32(footer[8:12])
-	tagSize := binary.LittleEndian.Uint32(footer[12:16]) // size of items + footer (32 bytes)
-	itemCount := binary.LittleEndian.Uint32(footer[16:20])
-	flags := binary.LittleEndian.Uint32(footer[20:24])
-
-	if version != apeTagVersion2 && version != 1000 {
-		return nil, fmt.Errorf("unsupported APE tag version: %d", version)
-	}
-	if tagSize < apeTagHeaderSize {
-		return nil, fmt.Errorf("APE tag size too small: %d", tagSize)
-	}
-	if itemCount > 1000 {
-		return nil, fmt.Errorf("APE tag item count too large: %d", itemCount)
-	}
-
-	// This should be the footer (bit 29 clear)
-	isHeader := (flags & apeTagFlagHeader) != 0
-	if isHeader {
-		return nil, fmt.Errorf("expected APE footer but found header")
-	}
-
-	// tagSize includes items + footer (32 bytes), but NOT the header.
-	itemsSize := int64(tagSize) - apeTagHeaderSize
-	if itemsSize < 0 {
-		return nil, fmt.Errorf("invalid APE tag: items size negative")
-	}
-
-	itemsOffset := footerOffset - itemsSize
-	if itemsOffset < 0 {
-		return nil, fmt.Errorf("APE tag items extend before file start")
-	}
-
-	itemsData := make([]byte, itemsSize)
-	if _, err := f.ReadAt(itemsData, itemsOffset); err != nil {
-		return nil, fmt.Errorf("failed to read APE items: %w", err)
-	}
-
-	items, err := parseAPEItems(itemsData, int(itemCount))
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse APE items: %w", err)
-	}
-
-	return &APETag{
-		Version:  version,
-		Items:    items,
-		ReadOnly: (flags & apeTagFlagReadOnly) != 0,
-	}, nil
-}
-
-func parseAPEItems(data []byte, count int) ([]APETagItem, error) {
-	items := make([]APETagItem, 0, count)
-	pos := 0
-
-	for i := 0; i < count && pos < len(data); i++ {
-		if pos+8 > len(data) {
-			break
-		}
-
-		valueSize := int(binary.LittleEndian.Uint32(data[pos : pos+4]))
-		itemFlags := binary.LittleEndian.Uint32(data[pos+4 : pos+8])
-		pos += 8
-
-		// Key is null-terminated ASCII (2-255 bytes, case-insensitive)
-		keyEnd := pos
-		for keyEnd < len(data) && data[keyEnd] != 0 {
-			keyEnd++
-		}
-		if keyEnd >= len(data) {
-			break
-		}
-
-		key := string(data[pos:keyEnd])
-		pos = keyEnd + 1
-
-		if pos+valueSize > len(data) {
-			break
-		}
-		value := string(data[pos : pos+valueSize])
-		pos += valueSize
-
-		items = append(items, APETagItem{
-			Key:   key,
-			Value: value,
-			Flags: itemFlags,
-		})
-	}
-
-	return items, nil
-}
-
-// WriteAPETags writes APEv2 tags to the end of a file.
-// If the file already has APEv2 tags, they are replaced.
-// The tag is written with both header and footer.
-func WriteAPETags(filePath string, tag *APETag) error {
-	existingSize, err := findExistingAPETagSize(filePath)
-	if err != nil {
-		return fmt.Errorf("failed to check existing APE tag: %w", err)
-	}
-
-	tagData, err := marshalAPETag(tag)
-	if err != nil {
-		return fmt.Errorf("failed to marshal APE tag: %w", err)
-	}
-
-	if existingSize > 0 {
-		fi, err := os.Stat(filePath)
-		if err != nil {
-			return fmt.Errorf("failed to stat file: %w", err)
-		}
-		newSize := fi.Size() - int64(existingSize)
-		if err := os.Truncate(filePath, newSize); err != nil {
-			return fmt.Errorf("failed to truncate existing APE tag: %w", err)
-		}
-	}
-
-	f, err := os.OpenFile(filePath, os.O_WRONLY|os.O_APPEND, 0644)
-	if err != nil {
-		return fmt.Errorf("failed to open file for writing: %w", err)
-	}
-	defer f.Close()
-
-	if _, err := f.Write(tagData); err != nil {
-		return fmt.Errorf("failed to write APE tag: %w", err)
-	}
-
-	return nil
-}
-
-// findExistingAPETagSize returns the total size of an existing APE tag
-// (header + items + footer) at the end of the file, or 0 if none exists.
-func findExistingAPETagSize(filePath string) (int64, error) {
-	f, err := os.Open(filePath)
-	if err != nil {
-		return 0, err
-	}
-	defer f.Close()
-
-	fi, err := f.Stat()
-	if err != nil {
-		return 0, err
-	}
-	fileSize := fi.Size()
-
-	offsets := []int64{fileSize - apeTagHeaderSize}
-	if fileSize > apeTagHeaderSize+128 {
-		offsets = append(offsets, fileSize-apeTagHeaderSize-128)
-	}
-
-	for _, offset := range offsets {
-		if offset < 0 {
-			continue
-		}
-		footer := make([]byte, apeTagHeaderSize)
-		if _, err := f.ReadAt(footer, offset); err != nil {
-			continue
-		}
-		if string(footer[0:8]) != apeTagPreamble {
-			continue
-		}
-
-		flags := binary.LittleEndian.Uint32(footer[20:24])
-		if (flags & apeTagFlagHeader) != 0 {
-			continue
-		}
-
-		tagSize := int64(binary.LittleEndian.Uint32(footer[12:16]))
-
-		hasHeader := (flags & (1 << 31)) != 0 // bit 31 = tag contains header
-		totalSize := tagSize
-		if hasHeader {
-			totalSize += apeTagHeaderSize
-		}
-
-		// Include any trailing data after the footer (e.g. ID3v1 128-byte tag).
-		// When truncating, we must remove the APE tag AND everything after it.
-		trailingBytes := fileSize - (offset + apeTagHeaderSize)
-		totalSize += trailingBytes
-
-		return totalSize, nil
-	}
-
-	return 0, nil
-}
-
-// marshalAPETag serializes an APETag into bytes (header + items + footer).
-func marshalAPETag(tag *APETag) ([]byte, error) {
-	if tag == nil || len(tag.Items) == 0 {
-		return nil, fmt.Errorf("empty APE tag")
-	}
-
-	var itemsData []byte
-	for _, item := range tag.Items {
-		keyBytes := []byte(item.Key)
-		valueBytes := []byte(item.Value)
-
-		// 4 bytes: value size (LE)
-		sizeBuf := make([]byte, 4)
-		binary.LittleEndian.PutUint32(sizeBuf, uint32(len(valueBytes)))
-
-		// 4 bytes: item flags (LE)
-		flagsBuf := make([]byte, 4)
-		binary.LittleEndian.PutUint32(flagsBuf, item.Flags)
-
-		itemsData = append(itemsData, sizeBuf...)
-		itemsData = append(itemsData, flagsBuf...)
-		itemsData = append(itemsData, keyBytes...)
-		itemsData = append(itemsData, 0)
-		itemsData = append(itemsData, valueBytes...)
-	}
-
-	// tagSize = items data + footer (32 bytes)
-	tagSize := uint32(len(itemsData) + apeTagHeaderSize)
-	itemCount := uint32(len(tag.Items))
-
-	version := uint32(apeTagVersion2)
-	if tag.Version != 0 {
-		version = tag.Version
-	}
-
-	// flags: bit 29 = 1 (is header), bit 31 = 1 (contains header)
-	headerFlags := uint32(apeTagFlagHeader | (1 << 31))
-	header := buildAPEHeaderFooter(version, tagSize, itemCount, headerFlags)
-
-	// flags: bit 29 = 0 (is footer), bit 31 = 1 (contains header)
-	footerFlags := uint32(1 << 31)
-	footer := buildAPEHeaderFooter(version, tagSize, itemCount, footerFlags)
-
-	// Final layout: header + items + footer
-	result := make([]byte, 0, len(header)+len(itemsData)+len(footer))
-	result = append(result, header...)
-	result = append(result, itemsData...)
-	result = append(result, footer...)
-
-	return result, nil
-}
-
-func buildAPEHeaderFooter(version, tagSize, itemCount, flags uint32) []byte {
-	buf := make([]byte, apeTagHeaderSize)
-	copy(buf[0:8], apeTagPreamble)
-	binary.LittleEndian.PutUint32(buf[8:12], version)
-	binary.LittleEndian.PutUint32(buf[12:16], tagSize)
-	binary.LittleEndian.PutUint32(buf[16:20], itemCount)
-	binary.LittleEndian.PutUint32(buf[20:24], flags)
-	// bytes 24-31 are reserved (zeros)
-	return buf
-}
-
-// APETagToAudioMetadata converts an APETag to our unified AudioMetadata struct.
-func APETagToAudioMetadata(tag *APETag) *AudioMetadata {
-	if tag == nil {
-		return nil
-	}
-
-	metadata := &AudioMetadata{}
-	for _, item := range tag.Items {
-		key := strings.ToUpper(strings.TrimSpace(item.Key))
-		value := strings.TrimSpace(item.Value)
-		if value == "" {
-			continue
-		}
-
-		switch key {
-		case "TITLE":
-			metadata.Title = value
-		case "ARTIST":
-			metadata.Artist = value
-		case "ALBUM":
-			metadata.Album = value
-		case "ALBUMARTIST", "ALBUM ARTIST":
-			metadata.AlbumArtist = value
-		case "GENRE":
-			metadata.Genre = value
-		case "YEAR":
-			metadata.Year = value
-		case "DATE":
-			metadata.Date = value
-		case "TRACK", "TRACKNUMBER":
-			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
-		case "DISC", "DISCNUMBER":
-			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
-		case "ISRC":
-			metadata.ISRC = value
-		case "LYRICS", "UNSYNCEDLYRICS":
-			if metadata.Lyrics == "" {
-				metadata.Lyrics = value
-			}
-		case "LABEL", "PUBLISHER":
-			metadata.Label = value
-		case "COPYRIGHT":
-			metadata.Copyright = value
-		case "COMPOSER":
-			metadata.Composer = value
-		case "COMMENT":
-			metadata.Comment = value
-		case "REPLAYGAIN_TRACK_GAIN":
-			metadata.ReplayGainTrackGain = value
-		case "REPLAYGAIN_TRACK_PEAK":
-			metadata.ReplayGainTrackPeak = value
-		case "REPLAYGAIN_ALBUM_GAIN":
-			metadata.ReplayGainAlbumGain = value
-		case "REPLAYGAIN_ALBUM_PEAK":
-			metadata.ReplayGainAlbumPeak = value
-		}
-	}
-
-	return metadata
-}
-
-// AudioMetadataToAPEItems converts metadata fields to APE tag items.
-func AudioMetadataToAPEItems(metadata *AudioMetadata) []APETagItem {
-	if metadata == nil {
-		return nil
-	}
-
-	var items []APETagItem
-	addItem := func(key, value string) {
-		if value != "" {
-			items = append(items, APETagItem{Key: key, Value: value})
-		}
-	}
-
-	addItem("Title", metadata.Title)
-	addItem("Artist", metadata.Artist)
-	addItem("Album", metadata.Album)
-	addItem("Album Artist", metadata.AlbumArtist)
-	addItem("Genre", metadata.Genre)
-	if metadata.Date != "" {
-		addItem("Year", metadata.Date)
-	} else if metadata.Year != "" {
-		addItem("Year", metadata.Year)
-	}
-	if metadata.TrackNumber > 0 {
-		addItem("Track", formatIndexValue(metadata.TrackNumber, metadata.TotalTracks))
-	}
-	if metadata.DiscNumber > 0 {
-		addItem("Disc", formatIndexValue(metadata.DiscNumber, metadata.TotalDiscs))
-	}
-	addItem("ISRC", metadata.ISRC)
-	addItem("Lyrics", metadata.Lyrics)
-	addItem("Label", metadata.Label)
-	addItem("Copyright", metadata.Copyright)
-	addItem("Composer", metadata.Composer)
-	addItem("Comment", metadata.Comment)
-	addItem("REPLAYGAIN_TRACK_GAIN", metadata.ReplayGainTrackGain)
-	addItem("REPLAYGAIN_TRACK_PEAK", metadata.ReplayGainTrackPeak)
-	addItem("REPLAYGAIN_ALBUM_GAIN", metadata.ReplayGainAlbumGain)
-	addItem("REPLAYGAIN_ALBUM_PEAK", metadata.ReplayGainAlbumPeak)
-
-	return items
-}
-
-// apeKeysFromFields builds a set of upper-case APE tag keys corresponding to
-// the metadata fields map sent by the editor.  This is used during merge to
-// ensure that even empty (cleared) fields override old values.
-func apeKeysFromFields(fields map[string]string) map[string]struct{} {
-	mapping := map[string]string{
-		"title":                 "TITLE",
-		"artist":                "ARTIST",
-		"album":                 "ALBUM",
-		"album_artist":          "ALBUM ARTIST",
-		"date":                  "DATE",
-		"genre":                 "GENRE",
-		"track_number":          "TRACK",
-		"disc_number":           "DISC",
-		"isrc":                  "ISRC",
-		"lyrics":                "LYRICS",
-		"label":                 "LABEL",
-		"copyright":             "COPYRIGHT",
-		"composer":              "COMPOSER",
-		"comment":               "COMMENT",
-		"replaygain_track_gain": "REPLAYGAIN_TRACK_GAIN",
-		"replaygain_track_peak": "REPLAYGAIN_TRACK_PEAK",
-		"replaygain_album_gain": "REPLAYGAIN_ALBUM_GAIN",
-		"replaygain_album_peak": "REPLAYGAIN_ALBUM_PEAK",
-	}
-	result := make(map[string]struct{})
-	for fk, apeKey := range mapping {
-		if _, present := fields[fk]; present {
-			result[strings.ToUpper(apeKey)] = struct{}{}
-		}
-	}
-	// Some fields have reader aliases that must also be cleared when the
-	// canonical key is updated (e.g. DATE writer ↔ DATE/YEAR reader,
-	// DISC ↔ DISCNUMBER, TRACK ↔ TRACKNUMBER, "ALBUM ARTIST" ↔ ALBUMARTIST,
-	// LABEL ↔ PUBLISHER, LYRICS ↔ UNSYNCEDLYRICS).
-	if _, present := fields["date"]; present {
-		result["DATE"] = struct{}{}
-	}
-	if _, present := fields["disc_number"]; present {
-		result["DISCNUMBER"] = struct{}{}
-	}
-	if _, present := fields["disc_total"]; present {
-		result["DISCNUMBER"] = struct{}{}
-	}
-	if _, present := fields["track_number"]; present {
-		result["TRACKNUMBER"] = struct{}{}
-	}
-	if _, present := fields["track_total"]; present {
-		result["TRACKNUMBER"] = struct{}{}
-	}
-	if _, present := fields["album_artist"]; present {
-		result["ALBUMARTIST"] = struct{}{}
-	}
-	if _, present := fields["label"]; present {
-		result["PUBLISHER"] = struct{}{}
-	}
-	if _, present := fields["lyrics"]; present {
-		result["UNSYNCEDLYRICS"] = struct{}{}
-	}
-	return result
-}
-
-// MergeAPEItems overlays newItems on top of existing items.
-// For each new item, if a matching key exists (case-insensitive) in existing,
-// it is replaced. New keys are appended. Existing items whose keys are NOT
-// in newItems are preserved (cover art, ReplayGain, custom tags, etc.).
-//
-// overrideKeys is an optional set of upper-case keys that should be removed
-// from existing even if they do not appear in newItems.  This handles field
-// deletion: the caller sends an empty value which is not serialized into
-// newItems, but the old value must still be dropped.
-func MergeAPEItems(existing, newItems []APETagItem, overrideKeys map[string]struct{}) []APETagItem {
-	combined := make(map[string]struct{}, len(newItems)+len(overrideKeys))
-	for k := range overrideKeys {
-		combined[strings.ToUpper(k)] = struct{}{}
-	}
-	for _, item := range newItems {
-		combined[strings.ToUpper(item.Key)] = struct{}{}
-	}
-
-	var merged []APETagItem
-	for _, item := range existing {
-		if _, overwritten := combined[strings.ToUpper(item.Key)]; !overwritten {
-			merged = append(merged, item)
-		}
-	}
-
-	merged = append(merged, newItems...)
-
-	return merged
-}
-
-// ReadAPETagsFromReader reads APEv2 tags from an io.ReaderAt + size.
-// This is useful for reading APE tags from files opened via SAF or other abstractions.
-func ReadAPETagsFromReader(r io.ReaderAt, fileSize int64) (*APETag, error) {
-	if fileSize < apeTagHeaderSize {
-		return nil, fmt.Errorf("file too small for APE tag")
-	}
-
-	footer := make([]byte, apeTagHeaderSize)
-	if _, err := r.ReadAt(footer, fileSize-apeTagHeaderSize); err != nil {
-		return nil, fmt.Errorf("failed to read APE footer: %w", err)
-	}
-
-	if string(footer[0:8]) == apeTagPreamble {
-		tag, err := parseAPETagFromFooter(r, fileSize, fileSize-apeTagHeaderSize, footer)
-		if err == nil {
-			return tag, nil
-		}
-	}
-
-	// Retry: skip ID3v1 tag (128 bytes)
-	if fileSize > apeTagHeaderSize+128 {
-		offset := fileSize - apeTagHeaderSize - 128
-		if _, err := r.ReadAt(footer, offset); err == nil {
-			if string(footer[0:8]) == apeTagPreamble {
-				tag, err := parseAPETagFromFooter(r, fileSize, offset, footer)
-				if err == nil {
-					return tag, nil
-				}
-			}
-		}
-	}
-
-	return nil, fmt.Errorf("no APEv2 tag found")
-}
-
-func parseAPETagFromFooter(r io.ReaderAt, fileSize, footerOffset int64, footer []byte) (*APETag, error) {
-	version := binary.LittleEndian.Uint32(footer[8:12])
-	tagSize := binary.LittleEndian.Uint32(footer[12:16])
-	itemCount := binary.LittleEndian.Uint32(footer[16:20])
-	flags := binary.LittleEndian.Uint32(footer[20:24])
-
-	if version != apeTagVersion2 && version != 1000 {
-		return nil, fmt.Errorf("unsupported APE tag version: %d", version)
-	}
-	if tagSize < apeTagHeaderSize {
-		return nil, fmt.Errorf("APE tag size too small: %d", tagSize)
-	}
-	if itemCount > 1000 {
-		return nil, fmt.Errorf("APE tag item count too large: %d", itemCount)
-	}
-	if (flags & apeTagFlagHeader) != 0 {
-		return nil, fmt.Errorf("expected footer, found header")
-	}
-
-	itemsSize := int64(tagSize) - apeTagHeaderSize
-	itemsOffset := footerOffset - itemsSize
-	if itemsOffset < 0 {
-		return nil, fmt.Errorf("APE items extend before file start")
-	}
-
-	itemsData := make([]byte, itemsSize)
-	if _, err := r.ReadAt(itemsData, itemsOffset); err != nil {
-		return nil, fmt.Errorf("failed to read APE items: %w", err)
-	}
-
-	items, err := parseAPEItems(itemsData, int(itemCount))
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse APE items: %w", err)
-	}
-
-	return &APETag{
-		Version:  version,
-		Items:    items,
-		ReadOnly: (flags & apeTagFlagReadOnly) != 0,
-	}, nil
-}

go_backend/ape_tags_supplement_test.go

@@ -1,121 +0,0 @@
-package gobackend
-
-import (
-	"bytes"
-	"os"
-	"path/filepath"
-	"testing"
-)
-
-func TestAPETagReadWriteMergeAndMetadataConversion(t *testing.T) {
-	dir := t.TempDir()
-	path := filepath.Join(dir, "sample.ape")
-	if err := os.WriteFile(path, []byte("audio-data"), 0600); err != nil {
-		t.Fatalf("write sample: %v", err)
-	}
-
-	metadata := &AudioMetadata{
-		Title:               "Song",
-		Artist:              "Artist",
-		Album:               "Album",
-		AlbumArtist:         "Album Artist",
-		Genre:               "Pop",
-		Date:                "2026",
-		TrackNumber:         3,
-		TotalTracks:         12,
-		DiscNumber:          1,
-		TotalDiscs:          2,
-		ISRC:                "USRC17607839",
-		Lyrics:              "lyrics",
-		Label:               "Label",
-		Copyright:           "Copyright",
-		Composer:            "Composer",
-		Comment:             "Comment",
-		ReplayGainTrackGain: "-6.50 dB",
-		ReplayGainTrackPeak: "0.98",
-		ReplayGainAlbumGain: "-5.00 dB",
-		ReplayGainAlbumPeak: "0.99",
-	}
-	items := AudioMetadataToAPEItems(metadata)
-	if len(items) == 0 {
-		t.Fatal("expected APE items")
-	}
-
-	tag := &APETag{Items: append(items, APETagItem{Key: "Custom", Value: "Keep"})}
-	if err := WriteAPETags(path, tag); err != nil {
-		t.Fatalf("WriteAPETags: %v", err)
-	}
-
-	readTag, err := ReadAPETags(path)
-	if err != nil {
-		t.Fatalf("ReadAPETags: %v", err)
-	}
-	if readTag.Version != apeTagVersion2 {
-		t.Fatalf("version = %d", readTag.Version)
-	}
-	readMetadata := APETagToAudioMetadata(readTag)
-	if readMetadata.Title != "Song" || readMetadata.TrackNumber != 3 || readMetadata.TotalTracks != 12 {
-		t.Fatalf("metadata = %#v", readMetadata)
-	}
-
-	readerTag, err := ReadAPETagsFromReader(bytes.NewReader(mustReadFile(t, path)), int64(len(mustReadFile(t, path))))
-	if err != nil {
-		t.Fatalf("ReadAPETagsFromReader: %v", err)
-	}
-	if len(readerTag.Items) != len(readTag.Items) {
-		t.Fatalf("reader items = %d, file items = %d", len(readerTag.Items), len(readTag.Items))
-	}
-
-	override := apeKeysFromFields(map[string]string{"title": "", "lyrics": "", "disc_total": ""})
-	merged := MergeAPEItems(readTag.Items, []APETagItem{{Key: "Title", Value: "New Song"}}, override)
-	mergedMeta := APETagToAudioMetadata(&APETag{Items: merged})
-	if mergedMeta.Title != "New Song" {
-		t.Fatalf("merged title = %q", mergedMeta.Title)
-	}
-	if mergedMeta.Lyrics != "" {
-		t.Fatalf("expected lyrics cleared, got %q", mergedMeta.Lyrics)
-	}
-
-	if err := WriteAPETags(path, &APETag{Items: []APETagItem{{Key: "Title", Value: "Replacement"}}}); err != nil {
-		t.Fatalf("replace APE tags: %v", err)
-	}
-	replaced, err := ReadAPETags(path)
-	if err != nil {
-		t.Fatalf("read replacement: %v", err)
-	}
-	if got := APETagToAudioMetadata(replaced).Title; got != "Replacement" {
-		t.Fatalf("replacement title = %q", got)
-	}
-
-	if _, err := marshalAPETag(nil); err == nil {
-		t.Fatal("expected empty tag error")
-	}
-	if _, err := ReadAPETags(filepath.Join(dir, "missing.ape")); err == nil {
-		t.Fatal("expected missing file error")
-	}
-	if _, err := ReadAPETagsFromReader(bytes.NewReader([]byte("short")), 5); err == nil {
-		t.Fatal("expected small reader error")
-	}
-}
-
-func TestAPETagInvalidFooterBranches(t *testing.T) {
-	footer := buildAPEHeaderFooter(9999, apeTagHeaderSize, 1, 0)
-	if _, err := parseAPETagFromFooter(bytes.NewReader(footer), int64(len(footer)), 0, footer); err == nil {
-		t.Fatal("expected unsupported version")
-	}
-
-	footer = buildAPEHeaderFooter(apeTagVersion2, apeTagHeaderSize-1, 1, 0)
-	if _, err := parseAPETagFromFooter(bytes.NewReader(footer), int64(len(footer)), 0, footer); err == nil {
-		t.Fatal("expected small tag size")
-	}
-
-	footer = buildAPEHeaderFooter(apeTagVersion2, apeTagHeaderSize, 1001, 0)
-	if _, err := parseAPETagFromFooter(bytes.NewReader(footer), int64(len(footer)), 0, footer); err == nil {
-		t.Fatal("expected too many items")
-	}
-
-	footer = buildAPEHeaderFooter(apeTagVersion2, apeTagHeaderSize, 1, apeTagFlagHeader)
-	if _, err := parseAPETagFromFooter(bytes.NewReader(footer), int64(len(footer)), 0, footer); err == nil {
-		t.Fatal("expected header flag error")
-	}
-}

go_backend/audio_metadata.go

@@ -21,20 +21,13 @@ type AudioMetadata struct {
 	Year        string
 	Date        string
 	TrackNumber int
-	TotalTracks int
 	DiscNumber  int
-	TotalDiscs  int
 	ISRC        string
 	Lyrics      string
 	Label       string
 	Copyright   string
 	Composer    string
 	Comment     string
-	// ReplayGain fields (text values, e.g. "-6.50 dB", "0.988831")
-	ReplayGainTrackGain string
-	ReplayGainTrackPeak string
-	ReplayGainAlbumGain string
-	ReplayGainAlbumPeak string
 }
 
 type MP3Quality struct {
@@ -175,9 +168,9 @@ func parseID3v22Frames(data []byte, metadata *AudioMetadata, tagUnsync bool) {
 		case "TCO":
 			metadata.Genre = cleanGenre(value)
 		case "TRK":
-			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
+			metadata.TrackNumber = parseTrackNumber(value)
 		case "TPA":
-			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
+			metadata.DiscNumber = parseTrackNumber(value)
 		case "TCM":
 			metadata.Composer = value
 		case "TPB":
@@ -294,9 +287,9 @@ func parseID3v23Frames(data []byte, metadata *AudioMetadata, version byte, tagUn
 		case "TCON":
 			metadata.Genre = cleanGenre(value)
 		case "TRCK":
-			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
+			metadata.TrackNumber = parseTrackNumber(value)
 		case "TPOS":
-			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
+			metadata.DiscNumber = parseTrackNumber(value)
 		case "TSRC":
 			metadata.ISRC = value
 		case "TCOM":
@@ -318,17 +311,6 @@ func parseID3v23Frames(data []byte, metadata *AudioMetadata, version byte, tagUn
 			if isLyricsDescription(desc) && userValue != "" && metadata.Lyrics == "" {
 				metadata.Lyrics = userValue
 			}
-			upperDesc := strings.ToUpper(desc)
-			switch upperDesc {
-			case "REPLAYGAIN_TRACK_GAIN":
-				metadata.ReplayGainTrackGain = userValue
-			case "REPLAYGAIN_TRACK_PEAK":
-				metadata.ReplayGainTrackPeak = userValue
-			case "REPLAYGAIN_ALBUM_GAIN":
-				metadata.ReplayGainAlbumGain = userValue
-			case "REPLAYGAIN_ALBUM_PEAK":
-				metadata.ReplayGainAlbumPeak = userValue
-			}
 		}
 
 		pos += 10 + frameSize
@@ -356,6 +338,7 @@ func readID3v1(file *os.File) (*AudioMetadata, error) {
 		Year:   strings.TrimRight(string(tag[93:97]), " \x00"),
 	}
 
+	// ID3v1.1 track number (if byte 125 is 0 and byte 126 is not)
 	if tag[125] == 0 && tag[126] != 0 {
 		metadata.TrackNumber = int(tag[126])
 	}
@@ -390,23 +373,27 @@ func extractTextFrame(data []byte) string {
 	}
 }
 
+// extractCommentFrame parses an ID3v2 COMM frame.
+// Format: encoding(1) + language(3) + description(null-terminated) + text
 func extractCommentFrame(data []byte) string {
 	if len(data) < 5 {
 		return ""
 	}
 	encoding := data[0]
+	// skip 3-byte language code
 	rest := data[4:]
 
+	// find null terminator separating description from text
 	var text []byte
 	switch encoding {
-	case 1, 2:
+	case 1, 2: // UTF-16 variants use double-null terminator
 		for i := 0; i+1 < len(rest); i += 2 {
 			if rest[i] == 0 && rest[i+1] == 0 {
 				text = rest[i+2:]
 				break
 			}
 		}
-	default:
+	default: // ISO-8859-1 or UTF-8
 		idx := bytes.IndexByte(rest, 0)
 		if idx >= 0 && idx+1 < len(rest) {
 			text = rest[idx+1:]
@@ -419,30 +406,33 @@ func extractCommentFrame(data []byte) string {
 		return ""
 	}
 
+	// re-prepend encoding byte so extractTextFrame can decode properly
 	framed := make([]byte, 1+len(text))
 	framed[0] = encoding
 	copy(framed[1:], text)
 	return extractTextFrame(framed)
 }
 
+// extractLyricsFrame parses ID3 unsynchronized lyrics frames (USLT/ULT).
+// Format: encoding(1) + language(3) + description(null-terminated) + lyrics text.
 func extractLyricsFrame(data []byte) string {
 	if len(data) < 5 {
 		return ""
 	}
 
 	encoding := data[0]
-	rest := data[4:]
+	rest := data[4:] // skip 3-byte language code
 
 	var text []byte
 	switch encoding {
-	case 1, 2:
+	case 1, 2: // UTF-16 variants use double-null terminator
 		for i := 0; i+1 < len(rest); i += 2 {
 			if rest[i] == 0 && rest[i+1] == 0 {
 				text = rest[i+2:]
 				break
 			}
 		}
-	default:
+	default: // ISO-8859-1 or UTF-8
 		idx := bytes.IndexByte(rest, 0)
 		if idx >= 0 && idx+1 < len(rest) {
 			text = rest[idx+1:]
@@ -461,6 +451,8 @@ func extractLyricsFrame(data []byte) string {
 	return extractTextFrame(framed)
 }
 
+// extractUserTextFrame parses ID3 TXXX/TXX user text frame:
+// encoding(1) + description + separator + value.
 func extractUserTextFrame(data []byte) (string, string) {
 	if len(data) < 2 {
 		return "", ""
@@ -471,7 +463,7 @@ func extractUserTextFrame(data []byte) (string, string) {
 
 	var descRaw, valueRaw []byte
 	switch encoding {
-	case 1, 2:
+	case 1, 2: // UTF-16 variants
 		for i := 0; i+1 < len(payload); i += 2 {
 			if payload[i] == 0 && payload[i+1] == 0 {
 				descRaw = payload[:i]
@@ -479,7 +471,7 @@ func extractUserTextFrame(data []byte) (string, string) {
 				break
 			}
 		}
-	default:
+	default: // ISO-8859-1 or UTF-8
 		idx := bytes.IndexByte(payload, 0)
 		if idx >= 0 {
 			descRaw = payload[:idx]
@@ -582,26 +574,12 @@ func cleanGenre(genre string) string {
 }
 
 func parseTrackNumber(s string) int {
-	num, _ := parseIndexPair(s)
-	return num
-}
-
-func parseIndexPair(s string) (int, int) {
 	s = strings.TrimSpace(s)
-	if s == "" {
-		return 0, 0
-	}
-
-	first := s
-	second := ""
 	if idx := strings.Index(s, "/"); idx > 0 {
-		first = s[:idx]
-		second = s[idx+1:]
+		s = s[:idx]
 	}
-
-	num, _ := strconv.Atoi(strings.TrimSpace(first))
-	total, _ := strconv.Atoi(strings.TrimSpace(second))
-	return num, total
+	num, _ := strconv.Atoi(s)
+	return num
 }
 
 func removeUnsync(data []byte) []byte {
@@ -687,6 +665,7 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 
 	file.Seek(audioStart, io.SeekStart)
 
+	// Find first valid MP3 frame sync
 	frameHeader := make([]byte, 4)
 	var frameStart int64 = -1
 	for i := 0; i < 10000; i++ {
@@ -713,6 +692,8 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 	sampleRateIdx := (frameHeader[2] >> 2) & 0x03
 	channelMode := (frameHeader[3] >> 6) & 0x03
 
+	// Sample rate tables: [version][index]
+	// version: 0=MPEG2.5, 1=reserved, 2=MPEG2, 3=MPEG1
 	sampleRates := [][]int{
 		{11025, 12000, 8000},
 		{0, 0, 0},
@@ -723,12 +704,15 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 		quality.SampleRate = sampleRates[version][sampleRateIdx]
 	}
 
+	// Bitrate tables for all MPEG versions and layers
+	// MPEG1 Layer III
 	if version == 3 && layer == 1 {
 		bitrates := []int{0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0}
 		if bitrateIdx < 16 {
 			quality.Bitrate = bitrates[bitrateIdx] * 1000
 		}
 	}
+	// MPEG2/2.5 Layer III
 	if (version == 0 || version == 2) && layer == 1 {
 		bitrates := []int{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0}
 		if bitrateIdx < 16 {
@@ -736,11 +720,14 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 		}
 	}
 
+	// Determine samples per frame for duration calculation
 	samplesPerFrame := 1152 // MPEG1 Layer III
 	if version == 0 || version == 2 {
 		samplesPerFrame = 576 // MPEG2/2.5 Layer III
 	}
 
+	// Try to read Xing/VBRI header from the first frame for VBR info
+	// Xing header offset depends on MPEG version and channel mode
 	var xingOffset int
 	if version == 3 { // MPEG1
 		if channelMode == 3 { // Mono
@@ -756,6 +743,7 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 		}
 	}
 
+	// Read enough of the first frame to find Xing/VBRI header
 	xingBuf := make([]byte, 200)
 	file.Seek(frameStart+4, io.SeekStart)
 	n, _ := io.ReadFull(file, xingBuf)
@@ -765,6 +753,7 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 	vbrBytes := int64(0)
 	isVBR := false
 
+	// Check for Xing/Info header
 	if xingOffset+8 <= n {
 		tag := string(xingBuf[xingOffset : xingOffset+4])
 		if tag == "Xing" || tag == "Info" {
@@ -783,6 +772,7 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 		}
 	}
 
+	// Check for VBRI header (always at offset 32 from frame start + 4)
 	if !isVBR && 36+26 <= n {
 		if string(xingBuf[32:36]) == "VBRI" {
 			vbrBytes = int64(binary.BigEndian.Uint32(xingBuf[36+6 : 36+10]))
@@ -794,9 +784,11 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 	}
 
 	if isVBR && vbrFrames > 0 && quality.SampleRate > 0 {
+		// Accurate duration from total frames
 		totalSamples := int64(vbrFrames) * int64(samplesPerFrame)
 		quality.Duration = int(totalSamples / int64(quality.SampleRate))
 
+		// Accurate average bitrate
 		if vbrBytes > 0 && quality.Duration > 0 {
 			quality.Bitrate = int(vbrBytes * 8 / int64(quality.Duration))
 		} else if quality.Duration > 0 {
@@ -804,6 +796,7 @@ func GetMP3Quality(filePath string) (*MP3Quality, error) {
 			quality.Bitrate = int(audioSize * 8 / int64(quality.Duration))
 		}
 	} else if quality.Bitrate > 0 {
+		// CBR fallback: estimate duration from file size and frame bitrate
 		audioSize := fileSize - audioStart - 128 // subtract possible ID3v1 tag
 		if audioSize > 0 {
 			quality.Duration = int(audioSize * 8 / int64(quality.Bitrate))
@@ -990,6 +983,7 @@ func parseVorbisComments(data []byte, metadata *AudioMetadata) {
 	artistValues := make([]string, 0, 1)
 	albumArtistValues := make([]string, 0, 1)
 
+	// Read vendor string length
 	var vendorLen uint32
 	if err := binary.Read(reader, binary.LittleEndian, &vendorLen); err != nil {
 		return
@@ -1018,6 +1012,8 @@ func parseVorbisComments(data []byte, metadata *AudioMetadata) {
 		if commentLen > remaining {
 			break
 		}
+		// Large comment entries are typically METADATA_BLOCK_PICTURE.
+		// Skip them so we can continue parsing normal text tags after/before.
 		if commentLen > 512*1024 {
 			reader.Seek(int64(commentLen), io.SeekCurrent)
 			continue
@@ -1053,9 +1049,9 @@ func parseVorbisComments(data []byte, metadata *AudioMetadata) {
 		case "GENRE":
 			metadata.Genre = value
 		case "TRACKNUMBER", "TRACK":
-			metadata.TrackNumber, metadata.TotalTracks = parseIndexPair(value)
+			metadata.TrackNumber = parseTrackNumber(value)
 		case "DISCNUMBER", "DISC":
-			metadata.DiscNumber, metadata.TotalDiscs = parseIndexPair(value)
+			metadata.DiscNumber = parseTrackNumber(value)
 		case "ISRC":
 			metadata.ISRC = value
 		case "COMPOSER":
@@ -1070,14 +1066,6 @@ func parseVorbisComments(data []byte, metadata *AudioMetadata) {
 			metadata.Label = value
 		case "COPYRIGHT":
 			metadata.Copyright = value
-		case "REPLAYGAIN_TRACK_GAIN":
-			metadata.ReplayGainTrackGain = value
-		case "REPLAYGAIN_TRACK_PEAK":
-			metadata.ReplayGainTrackPeak = value
-		case "REPLAYGAIN_ALBUM_GAIN":
-			metadata.ReplayGainAlbumGain = value
-		case "REPLAYGAIN_ALBUM_PEAK":
-			metadata.ReplayGainAlbumPeak = value
 		}
 	}
 
@@ -1135,6 +1123,7 @@ func GetOggQuality(filePath string) (*OggQuality, error) {
 		}
 	}
 
+	// Read granule position from the last Ogg page for accurate duration
 	stat, err := file.Stat()
 	if err != nil {
 		return quality, nil
@@ -1144,6 +1133,7 @@ func GetOggQuality(filePath string) (*OggQuality, error) {
 	granule := readLastOggGranulePosition(file, fileSize)
 	if granule > 0 {
 		if isOpus {
+			// Opus always uses 48kHz granule position internally
 			totalSamples := granule - int64(preSkip)
 			if totalSamples > 0 {
 				durationSec := float64(totalSamples) / 48000.0
@@ -1161,9 +1151,11 @@ func GetOggQuality(filePath string) (*OggQuality, error) {
 		}
 	}
 
+	// Fallback bitrate estimate if duration exists but bitrate couldn't be derived.
 	if quality.Bitrate <= 0 && quality.Duration > 0 {
 		quality.Bitrate = int(fileSize * 8 / int64(quality.Duration))
 	}
+	// Guard against obviously invalid values from corrupted/unreliable granule reads.
 	if quality.Duration > 24*60*60 {
 		quality.Duration = 0
 		quality.Bitrate = 0
@@ -1175,7 +1167,10 @@ func GetOggQuality(filePath string) (*OggQuality, error) {
 	return quality, nil
 }
 
+// readLastOggGranulePosition seeks to the end of the file and scans backwards
+// to find the last Ogg page, then reads its granule position (bytes 6-13).
 func readLastOggGranulePosition(file *os.File, fileSize int64) int64 {
+	// Read the last chunk of the file to find the last OggS sync
 	searchSize := int64(65536)
 	if searchSize > fileSize {
 		searchSize = fileSize
@@ -1199,6 +1194,7 @@ func readLastOggGranulePosition(file *os.File, fileSize int64) int64 {
 		if i+27 > n {
 			continue
 		}
+		// Validate minimal header fields to avoid false positives inside payload bytes.
 		version := buf[i+4]
 		headerType := buf[i+5]
 		if version != 0 || headerType > 0x07 {
@@ -1216,6 +1212,7 @@ func readLastOggGranulePosition(file *os.File, fileSize int64) int64 {
 		if i+headerLen+payloadLen > n {
 			continue
 		}
+		// Granule position is at bytes 6-13 of the Ogg page header (little-endian int64).
 		return int64(binary.LittleEndian.Uint64(buf[i+6 : i+14]))
 	}
 	return 0
@@ -1275,6 +1272,7 @@ func extractMP3CoverArt(filePath string) ([]byte, string, error) {
 		return nil, "", err
 	}
 
+	// Parse frames looking for APIC (Attached Picture)
 	pos := 0
 	var frameIDLen, headerLen int
 	if majorVersion == 2 {
@@ -1305,6 +1303,7 @@ func extractMP3CoverArt(filePath string) ([]byte, string, error) {
 			break
 		}
 
+		// Check for APIC (ID3v2.3/2.4) or PIC (ID3v2.2)
 		if (frameIDLen == 4 && frameID == "APIC") || (frameIDLen == 3 && frameID == "PIC") {
 			frameData := tagData[pos+headerLen : pos+headerLen+frameSize]
 			imageData, mimeType := parseAPICFrame(frameData, majorVersion)

go_backend/audio_metadata_supplement_test.go

@@ -1,482 +0,0 @@
-package gobackend
-
-import (
-	"bytes"
-	"encoding/base64"
-	"encoding/binary"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-func TestAudioMetadataID3ParsingBranches(t *testing.T) {
-	dir := t.TempDir()
-	path := filepath.Join(dir, "tagged.mp3")
-	tag := buildID3v23Tag(
-		id3TextFrame("TIT2", "Title"),
-		id3TextFrame("TPE1", "Artist"),
-		id3TextFrame("TPE2", "Album Artist"),
-		id3TextFrame("TALB", "Album"),
-		id3TextFrame("TDRC", "2026-05-04"),
-		id3TextFrame("TCON", "(13)Pop"),
-		id3TextFrame("TRCK", "4/12"),
-		id3TextFrame("TPOS", "1/2"),
-		id3TextFrame("TSRC", "USRC17607839"),
-		id3TextFrame("TCOM", "Composer"),
-		id3TextFrame("TPUB", "Label"),
-		id3TextFrame("TCOP", "Copyright"),
-		id3CommentFrame("COMM", "Comment"),
-		id3CommentFrame("USLT", "Lyrics"),
-		id3UserTextFrame("TXXX", "REPLAYGAIN_TRACK_GAIN", "-6.50 dB"),
-		id3UserTextFrame("TXXX", "REPLAYGAIN_TRACK_PEAK", "0.98"),
-	)
-	if err := os.WriteFile(path, append(tag, []byte("audio")...), 0600); err != nil {
-		t.Fatalf("write ID3v2: %v", err)
-	}
-
-	meta, err := ReadID3Tags(path)
-	if err != nil {
-		t.Fatalf("ReadID3Tags: %v", err)
-	}
-	if meta.Title != "Title" || meta.TrackNumber != 4 || meta.TotalTracks != 12 || meta.Genre != "Pop" {
-		t.Fatalf("metadata = %#v", meta)
-	}
-	if meta.Comment != "Comment" || meta.Lyrics != "Lyrics" || meta.ReplayGainTrackGain == "" {
-		t.Fatalf("metadata comments/lyrics/replaygain = %#v", meta)
-	}
-
-	id3v1Path := filepath.Join(dir, "id3v1.mp3")
-	if err := os.WriteFile(id3v1Path, append([]byte("audio"), buildID3v1Tag("V1 Title", "V1 Artist", "V1 Album", "1999", 7, 13)...), 0600); err != nil {
-		t.Fatalf("write ID3v1: %v", err)
-	}
-	v1, err := ReadID3Tags(id3v1Path)
-	if err != nil {
-		t.Fatalf("ReadID3Tags v1: %v", err)
-	}
-	if v1.Title != "V1 Title" || v1.Artist != "V1 Artist" || v1.Genre == "" {
-		t.Fatalf("v1 = %#v", v1)
-	}
-
-	v22Path := filepath.Join(dir, "id3v22.mp3")
-	v22 := buildID3v22Tag(
-		id3v22TextFrame("TT2", "V22 Title"),
-		id3v22TextFrame("TP1", "V22 Artist"),
-		id3v22TextFrame("TRK", "2/5"),
-		id3v22CommentFrame("ULT", "V22 Lyrics"),
-	)
-	if err := os.WriteFile(v22Path, append(v22, []byte("audio")...), 0600); err != nil {
-		t.Fatalf("write ID3v2.2: %v", err)
-	}
-	v22Meta, err := ReadID3Tags(v22Path)
-	if err != nil {
-		t.Fatalf("ReadID3Tags v2.2: %v", err)
-	}
-	if v22Meta.Title != "V22 Title" || v22Meta.Artist != "V22 Artist" || v22Meta.Lyrics != "V22 Lyrics" {
-		t.Fatalf("v22 = %#v", v22Meta)
-	}
-
-	if got := decodeUTF16([]byte{0xff, 0xfe, 'H', 0, 'i', 0}); got != "Hi" {
-		t.Fatalf("decodeUTF16 = %q", got)
-	}
-	if got := decodeUTF16BE([]byte{0, 'O', 0, 'K'}); got != "OK" {
-		t.Fatalf("decodeUTF16BE = %q", got)
-	}
-	if n, total := parseIndexPair(" 8 / 10 "); n != 8 || total != 10 {
-		t.Fatalf("parseIndexPair = %d/%d", n, total)
-	}
-	if got := parseTrackNumber("9/11"); got != 9 {
-		t.Fatalf("parseTrackNumber = %d", got)
-	}
-	if got := removeUnsync([]byte{0xff, 0x00, 0xe0}); !bytes.Equal(got, []byte{0xff, 0xe0}) {
-		t.Fatalf("removeUnsync = %#v", got)
-	}
-	if got := extendedHeaderSize([]byte{0, 0, 0, 6, 0, 0, 0, 0, 0, 0}, 3); got != 10 {
-		t.Fatalf("extendedHeaderSize = %d", got)
-	}
-	if got := syncsafeToInt([]byte{0, 0, 2, 0}); got != 256 {
-		t.Fatalf("syncsafe = %d", got)
-	}
-}
-
-func TestAudioMetadataCoverAndQualityHelpers(t *testing.T) {
-	png := []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0, 0, 0, 0}
-	if detectCoverMIME("cover.jpg", png) != "image/png" || detectCoverMIME("cover.webp", []byte("RIFFxxxxWEBPdata")) != "image/webp" {
-		t.Fatal("cover MIME detection mismatch")
-	}
-	if _, err := buildPictureBlock("", nil); err == nil {
-		t.Fatal("expected empty picture block error")
-	}
-
-	apic := append([]byte{3}, []byte("image/png\x00")...)
-	apic = append(apic, 3, 0)
-	apic = append(apic, png...)
-	image, mime := parseAPICFrame(apic, 3)
-	if mime != "image/png" || !bytes.Equal(image, png) {
-		t.Fatalf("APIC = %s/%v", mime, image)
-	}
-	pic := append([]byte{0}, []byte("PNG")...)
-	pic = append(pic, 3, 0)
-	pic = append(pic, png...)
-	image, mime = parseAPICFrame(pic, 2)
-	if mime != "image/png" || !bytes.Equal(image, png) {
-		t.Fatalf("PIC = %s/%v", mime, image)
-	}
-
-	frame := make([]byte, 10)
-	copy(frame[:4], "APIC")
-	binary.BigEndian.PutUint32(frame[4:8], uint32(len(apic)))
-	tag := append(frame, apic...)
-	header := []byte{'I', 'D', '3', 3, 0, 0, byte(len(tag) >> 21), byte(len(tag) >> 14), byte(len(tag) >> 7), byte(len(tag))}
-	mp3CoverPath := filepath.Join(t.TempDir(), "cover.mp3")
-	if err := os.WriteFile(mp3CoverPath, append(append(header, tag...), []byte("audio")...), 0600); err != nil {
-		t.Fatal(err)
-	}
-	extracted, extractedMIME, err := extractMP3CoverArt(mp3CoverPath)
-	if err != nil || extractedMIME != "image/png" || !bytes.Equal(extracted, png) {
-		t.Fatalf("extractMP3CoverArt = %s/%v/%v", extractedMIME, extracted, err)
-	}
-
-	var picture bytes.Buffer
-	binary.Write(&picture, binary.BigEndian, uint32(3))
-	binary.Write(&picture, binary.BigEndian, uint32(len("image/png")))
-	picture.WriteString("image/png")
-	binary.Write(&picture, binary.BigEndian, uint32(0))
-	binary.Write(&picture, binary.BigEndian, uint32(1))
-	binary.Write(&picture, binary.BigEndian, uint32(1))
-	binary.Write(&picture, binary.BigEndian, uint32(32))
-	binary.Write(&picture, binary.BigEndian, uint32(0))
-	binary.Write(&picture, binary.BigEndian, uint32(len(png)))
-	picture.Write(png)
-	flacImage, flacMIME := parseFLACPictureBlock(picture.Bytes())
-	if flacMIME != "image/png" || !bytes.Equal(flacImage, png) {
-		t.Fatalf("FLAC picture = %s/%v", flacMIME, flacImage)
-	}
-
-	comment := "METADATA_BLOCK_PICTURE=" + base64.StdEncoding.EncodeToString(picture.Bytes())
-	var vorbis bytes.Buffer
-	binary.Write(&vorbis, binary.LittleEndian, uint32(6))
-	vorbis.WriteString("vendor")
-	binary.Write(&vorbis, binary.LittleEndian, uint32(1))
-	binary.Write(&vorbis, binary.LittleEndian, uint32(len(comment)))
-	vorbis.WriteString(comment)
-	commentImage, commentMIME := extractPictureFromVorbisComments(vorbis.Bytes())
-	if commentMIME != "image/png" || !bytes.Equal(commentImage, png) {
-		t.Fatalf("vorbis picture = %s/%v", commentMIME, commentImage)
-	}
-	decoded := make([]byte, base64StdDecodeLen(len("SGV sbG8="))+4)
-	n, err := base64StdDecode(decoded, []byte("SGV sbG8="))
-	if err != nil || strings.TrimRight(string(decoded[:n]), "\x00") != "Hello" {
-		t.Fatalf("base64 decode = %q/%v", decoded[:n], err)
-	}
-
-	if detectOggStreamType([][]byte{[]byte("OpusHeadxxxx")}) != oggStreamOpus {
-		t.Fatal("expected opus stream")
-	}
-	if detectOggStreamType([][]byte{append([]byte{1}, []byte("vorbisxxxx")...)}) != oggStreamVorbis {
-		t.Fatal("expected vorbis stream")
-	}
-
-	mp3Path := filepath.Join(t.TempDir(), "quality.mp3")
-	audio := append([]byte{0xFF, 0xFB, 0x90, 0x64}, bytes.Repeat([]byte{0}, 2000)...)
-	if err := os.WriteFile(mp3Path, audio, 0600); err != nil {
-		t.Fatal(err)
-	}
-	quality, err := GetMP3Quality(mp3Path)
-	if err != nil || quality.SampleRate != 44100 || quality.Bitrate != 128000 {
-		t.Fatalf("MP3 quality = %#v/%v", quality, err)
-	}
-	if _, _, err := extractMP3CoverArt(filepath.Join(t.TempDir(), "missing.mp3")); err == nil {
-		t.Fatal("expected missing MP3 cover error")
-	}
-}
-
-func TestM4AMetadataAtomHelpers(t *testing.T) {
-	dir := t.TempDir()
-	path := filepath.Join(dir, "tagged.m4a")
-	cover := []byte{0xFF, 0xD8, 0xFF, 0x00}
-	ilstPayload := []byte{}
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9nam", "M4A Title")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9ART", "M4A Artist")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9alb", "M4A Album")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("aART", "Album Artist")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9day", "2026")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9gen", "Pop")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9wrt", "Composer")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9cmt", "[ti:Comment Lyrics]")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("cprt", "Copyright")...)
-	ilstPayload = append(ilstPayload, buildM4ATextTag("\xa9lyr", "[00:00.00]M4A Lyrics")...)
-	ilstPayload = append(ilstPayload, buildM4AIndexTag("trkn", 3, 12)...)
-	ilstPayload = append(ilstPayload, buildM4AIndexTag("disk", 1, 2)...)
-	ilstPayload = append(ilstPayload, buildM4AFreeformAtom("ISRC", "USRC17607839")...)
-	ilstPayload = append(ilstPayload, buildM4AFreeformAtom("LABEL", "Label")...)
-	ilstPayload = append(ilstPayload, buildM4AFreeformAtom("REPLAYGAIN_TRACK_GAIN", "-6.50 dB")...)
-	ilstPayload = append(ilstPayload, buildM4AAtom("covr", buildM4AAtom("data", append([]byte{0, 0, 0, 13, 0, 0, 0, 0}, cover...)))...)
-	fileData := buildM4AFileWithIlst(ilstPayload, true)
-	if err := os.WriteFile(path, fileData, 0600); err != nil {
-		t.Fatal(err)
-	}
-
-	meta, err := ReadM4ATags(path)
-	if err != nil {
-		t.Fatalf("ReadM4ATags: %v", err)
-	}
-	if meta.Title != "M4A Title" || meta.Artist != "M4A Artist" || meta.TrackNumber != 3 || meta.TotalTracks != 12 || meta.ISRC != "USRC17607839" {
-		t.Fatalf("M4A metadata = %#v", meta)
-	}
-	if lyrics, err := extractLyricsFromM4A(path); err != nil || !strings.Contains(lyrics, "M4A Lyrics") {
-		t.Fatalf("extractLyricsFromM4A = %q/%v", lyrics, err)
-	}
-	if image, err := extractCoverFromM4A(path); err != nil || !bytes.Equal(image, cover) {
-		t.Fatalf("extractCoverFromM4A = %#v/%v", image, err)
-	}
-	if pathInfo, err := func() (m4aMetadataPath, error) {
-		f, err := os.Open(path)
-		if err != nil {
-			return m4aMetadataPath{}, err
-		}
-		defer f.Close()
-		info, _ := f.Stat()
-		return findM4AMetadataPath(f, info.Size())
-	}(); err != nil || pathInfo.udta == nil {
-		t.Fatalf("findM4AMetadataPath = %#v/%v", pathInfo, err)
-	}
-	if err := EditM4AReplayGain(path, map[string]string{"replaygain_track_gain": "-5.00 dB", "replaygain_track_peak": "0.98"}); err != nil {
-		t.Fatalf("EditM4AReplayGain: %v", err)
-	}
-	edited, err := ReadM4ATags(path)
-	if err != nil || edited.ReplayGainTrackGain != "-5.00 dB" || edited.ReplayGainTrackPeak != "0.98" {
-		t.Fatalf("edited M4A = %#v/%v", edited, err)
-	}
-
-	noUdtaPath := filepath.Join(dir, "noudta.m4a")
-	if err := os.WriteFile(noUdtaPath, buildM4AFileWithIlst(buildM4ATextTag("\xa9nam", "No Udta"), false), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if meta, err := ReadM4ATags(noUdtaPath); err != nil || meta.Title != "No Udta" {
-		t.Fatalf("ReadM4ATags no udta = %#v/%v", meta, err)
-	}
-	if _, err := ReadM4ATags(filepath.Join(dir, "missing.m4a")); err == nil {
-		t.Fatal("expected missing M4A error")
-	}
-	emptyM4A := filepath.Join(dir, "empty.m4a")
-	if err := os.WriteFile(emptyM4A, buildM4AFileWithIlst(nil, true), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := ReadM4ATags(emptyM4A); err == nil {
-		t.Fatal("expected empty M4A tags error")
-	}
-	if _, err := extractCoverFromM4A(emptyM4A); err == nil {
-		t.Fatal("expected missing M4A cover error")
-	}
-	if _, err := extractLyricsFromM4A(emptyM4A); err == nil {
-		t.Fatal("expected missing M4A lyrics error")
-	}
-
-	sidecarAudio := filepath.Join(dir, "sidecar.mp3")
-	if err := os.WriteFile(sidecarAudio, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(dir, "sidecar.lrc"), []byte(" [00:00.00]Sidecar "), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if lyrics, err := extractLyricsFromSidecarLRC(sidecarAudio); err != nil || !strings.Contains(lyrics, "Sidecar") {
-		t.Fatalf("sidecar lyrics = %q/%v", lyrics, err)
-	}
-	if !looksLikeEmbeddedLyrics("[ti:Song]") || !looksLikeEmbeddedLyrics("[00:00.00]Line\n[00:01.00]Next") || looksLikeEmbeddedLyrics("plain") {
-		t.Fatal("embedded lyric heuristic mismatch")
-	}
-	if formatIndexValue(3, 12) != "3/12" || formatIndexValue(3, 0) != "3" || formatIndexValue(0, 12) != "" {
-		t.Fatal("formatIndexValue mismatch")
-	}
-	if parsePositiveInt(" 42 ") != 42 || parsePositiveInt("bad") != 0 {
-		t.Fatal("parsePositiveInt mismatch")
-	}
-	if !hasMapKey(map[string]string{"x": "y"}, "x") {
-		t.Fatal("expected map key")
-	}
-	if _, ok := parseReplayGainDb("-6.50 dB"); !ok {
-		t.Fatal("expected ReplayGain dB parse")
-	}
-	if _, ok := parseReplayGainPeak("0.98"); !ok {
-		t.Fatal("expected ReplayGain peak parse")
-	}
-	if norm := buildITunNORMTag("-6.50 dB", "0.98"); norm == "" {
-		t.Fatal("expected iTunNORM")
-	}
-	if fields := collectM4AReplayGainFields(map[string]string{"replaygain_track_gain": "-6 dB", "replaygain_track_peak": "0.9"}); fields["iTunNORM"] == "" {
-		t.Fatalf("ReplayGain fields = %#v", fields)
-	}
-
-	qualityPath := filepath.Join(dir, "quality.m4a")
-	mvhd := make([]byte, 20)
-	binary.BigEndian.PutUint32(mvhd[12:16], 1000)
-	binary.BigEndian.PutUint32(mvhd[16:20], 180000)
-	sampleEntry := make([]byte, 32)
-	copy(sampleEntry[0:4], "mp4a")
-	binary.BigEndian.PutUint16(sampleEntry[22:24], 24)
-	sampleEntry[28] = 0xAC
-	sampleEntry[29] = 0x44
-	qualityFile := append(buildM4AAtom("ftyp", []byte("M4A \x00\x00\x00\x00")), buildM4AAtom("moov", append(buildM4AAtom("mvhd", mvhd), sampleEntry...))...)
-	if err := os.WriteFile(qualityPath, qualityFile, 0600); err != nil {
-		t.Fatal(err)
-	}
-	if quality, err := GetM4AQuality(qualityPath); err != nil || quality.BitDepth != 24 || quality.SampleRate != 44100 || quality.Duration != 180 {
-		t.Fatalf("GetM4AQuality = %#v/%v", quality, err)
-	}
-	if quality, err := GetAudioQuality(qualityPath); err != nil || quality.SampleRate != 44100 {
-		t.Fatalf("GetAudioQuality M4A = %#v/%v", quality, err)
-	}
-	if _, _, ok := parseALACSpecificConfig(make([]byte, 4)); ok {
-		t.Fatal("short ALAC config should not parse")
-	}
-	alac := make([]byte, 24)
-	alac[5] = 16
-	binary.BigEndian.PutUint32(alac[20:24], 48000)
-	if depth, rate, ok := parseALACSpecificConfig(alac); !ok || depth != 16 || rate != 48000 {
-		t.Fatalf("ALAC config = %d/%d/%v", depth, rate, ok)
-	}
-}
-
-func TestOggMetadataQualityAndCoverHelpers(t *testing.T) {
-	dir := t.TempDir()
-	opusHead := make([]byte, 19)
-	copy(opusHead[0:8], "OpusHead")
-	binary.LittleEndian.PutUint16(opusHead[10:12], 312)
-	binary.LittleEndian.PutUint32(opusHead[12:16], 48000)
-
-	var comments bytes.Buffer
-	binary.Write(&comments, binary.LittleEndian, uint32(6))
-	comments.WriteString("vendor")
-	entries := []string{
-		"TITLE=Ogg Title",
-		"ARTIST=Artist",
-		"ALBUMARTIST=Album Artist",
-		"TRACKNUMBER=2/9",
-		"DISCNUMBER=1/2",
-		"LYRICS=[00:00.00]Ogg Lyrics",
-	}
-	binary.Write(&comments, binary.LittleEndian, uint32(len(entries)))
-	for _, entry := range entries {
-		binary.Write(&comments, binary.LittleEndian, uint32(len(entry)))
-		comments.WriteString(entry)
-	}
-	opusTags := append([]byte("OpusTags"), comments.Bytes()...)
-	oggPath := filepath.Join(dir, "tagged.opus")
-	oggData := append(buildOggPage(0x02, 0, opusHead), buildOggPage(0x00, 48000+312, opusTags)...)
-	if err := os.WriteFile(oggPath, oggData, 0600); err != nil {
-		t.Fatal(err)
-	}
-	quality, err := GetOggQuality(oggPath)
-	if err != nil || quality.SampleRate != 48000 || quality.Duration != 1 {
-		t.Fatalf("GetOggQuality = %#v/%v", quality, err)
-	}
-	meta, err := ReadOggVorbisComments(oggPath)
-	if err != nil || meta.Title != "Ogg Title" || meta.TrackNumber != 2 || meta.TotalTracks != 9 {
-		t.Fatalf("ReadOggVorbisComments = %#v/%v", meta, err)
-	}
-
-	picture := buildTestFLACPictureBlock([]byte{0x89, 0x50, 0x4E, 0x47}, "image/png")
-	pictureComment := "METADATA_BLOCK_PICTURE=" + base64.StdEncoding.EncodeToString(picture)
-	var coverComments bytes.Buffer
-	binary.Write(&coverComments, binary.LittleEndian, uint32(6))
-	coverComments.WriteString("vendor")
-	binary.Write(&coverComments, binary.LittleEndian, uint32(1))
-	binary.Write(&coverComments, binary.LittleEndian, uint32(len(pictureComment)))
-	coverComments.WriteString(pictureComment)
-	coverPath := filepath.Join(dir, "cover.opus")
-	coverData := append(buildOggPage(0x02, 0, opusHead), buildOggPage(0x00, 48000+312, append([]byte("OpusTags"), coverComments.Bytes()...))...)
-	if err := os.WriteFile(coverPath, coverData, 0600); err != nil {
-		t.Fatal(err)
-	}
-	if image, mime, err := extractOggCoverArt(coverPath); err != nil || mime != "image/png" || len(image) == 0 {
-		t.Fatalf("extractOggCoverArt = %s/%#v/%v", mime, image, err)
-	}
-	if image, mime, err := extractAnyCoverArtWithHint(coverPath, "cover.opus"); err != nil || mime != "image/png" || len(image) == 0 {
-		t.Fatalf("extractAnyCoverArtWithHint = %s/%#v/%v", mime, image, err)
-	}
-	if image, mime, err := extractAnyCoverArt(coverPath); err != nil || mime != "image/png" || len(image) == 0 {
-		t.Fatalf("extractAnyCoverArt = %s/%#v/%v", mime, image, err)
-	}
-	extractedCoverPath := filepath.Join(dir, "extracted.png")
-	if err := ExtractCoverToFile(coverPath, extractedCoverPath); err != nil {
-		t.Fatalf("ExtractCoverToFile = %v", err)
-	}
-	if data := mustReadFile(t, extractedCoverPath); len(data) == 0 {
-		t.Fatal("expected extracted cover data")
-	}
-	cachePath, err := SaveCoverToCacheWithHintAndKey(coverPath, "cover.opus", dir, "key")
-	if err != nil || cachePath == "" {
-		t.Fatalf("SaveCoverToCacheWithHintAndKey = %q/%v", cachePath, err)
-	}
-	cacheDir := filepath.Join(dir, "cache")
-	if path, err := SaveCoverToCache(coverPath, cacheDir); err != nil || !strings.HasSuffix(path, ".png") {
-		t.Fatalf("SaveCoverToCache = %q/%v", path, err)
-	}
-	if path, err := SaveCoverToCacheWithHint(coverPath, "cover.opus", cacheDir); err != nil || path == "" {
-		t.Fatalf("SaveCoverToCacheWithHint = %q/%v", path, err)
-	}
-	hitPath, err := SaveCoverToCache(coverPath, cacheDir)
-	if err != nil || hitPath == "" {
-		t.Fatalf("SaveCoverToCache cache hit = %q/%v", hitPath, err)
-	}
-	if _, err := SaveCoverToCacheWithHintAndKey(filepath.Join(dir, "missing.opus"), "missing.opus", dir, "missing"); err == nil {
-		t.Fatal("expected missing cover cache error")
-	}
-
-	badPath := filepath.Join(dir, "bad.ogg")
-	if err := os.WriteFile(badPath, []byte("bad"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := GetOggQuality(badPath); err == nil {
-		t.Fatal("expected invalid Ogg quality error")
-	}
-}
-
-func buildM4ADataPayload(payload []byte) []byte {
-	return append([]byte{0, 0, 0, 1, 0, 0, 0, 0}, payload...)
-}
-
-func buildM4ATextTag(atomType, value string) []byte {
-	return buildM4AAtom(atomType, buildM4AAtom("data", buildM4ADataPayload([]byte(value))))
-}
-
-func buildM4AIndexTag(atomType string, number, total int) []byte {
-	payload := []byte{0, 0, 0, byte(number), 0, byte(total), 0, 0}
-	return buildM4AAtom(atomType, buildM4AAtom("data", buildM4ADataPayload(payload)))
-}
-
-func buildM4AFileWithIlst(ilstPayload []byte, withUdta bool) []byte {
-	ilst := buildM4AAtom("ilst", ilstPayload)
-	meta := buildM4AAtom("meta", append([]byte{0, 0, 0, 0}, ilst...))
-	moovPayload := meta
-	if withUdta {
-		moovPayload = buildM4AAtom("udta", meta)
-	}
-	return append(buildM4AAtom("ftyp", []byte("M4A \x00\x00\x00\x00")), buildM4AAtom("moov", moovPayload)...)
-}
-
-func buildOggPage(headerType byte, granule uint64, packet []byte) []byte {
-	header := make([]byte, 27)
-	copy(header[0:4], "OggS")
-	header[4] = 0
-	header[5] = headerType
-	binary.LittleEndian.PutUint64(header[6:14], granule)
-	header[26] = 1
-	return append(append(header, byte(len(packet))), packet...)
-}
-
-func buildTestFLACPictureBlock(image []byte, mime string) []byte {
-	var picture bytes.Buffer
-	binary.Write(&picture, binary.BigEndian, uint32(3))
-	binary.Write(&picture, binary.BigEndian, uint32(len(mime)))
-	picture.WriteString(mime)
-	binary.Write(&picture, binary.BigEndian, uint32(0))
-	binary.Write(&picture, binary.BigEndian, uint32(1))
-	binary.Write(&picture, binary.BigEndian, uint32(1))
-	binary.Write(&picture, binary.BigEndian, uint32(32))
-	binary.Write(&picture, binary.BigEndian, uint32(0))
-	binary.Write(&picture, binary.BigEndian, uint32(len(image)))
-	picture.Write(image)
-	return picture.Bytes()
-}

go_backend/cancel.go

@@ -9,23 +9,14 @@ import (
 // ErrDownloadCancelled is returned when a download is cancelled by the user.
 var ErrDownloadCancelled = errors.New("download cancelled")
 
-// ErrExtensionRequestCancelled is returned when a UI-driven extension request
-// is superseded by a newer home/search request.
-var ErrExtensionRequestCancelled = errors.New("extension request cancelled")
-
 type cancelEntry struct {
-	ctx      context.Context
 	cancel   context.CancelFunc
 	canceled bool
-	refs     int
 }
 
 var (
 	cancelMu  sync.Mutex
 	cancelMap = make(map[string]*cancelEntry)
-
-	extensionRequestCancelMu  sync.Mutex
-	extensionRequestCancelMap = make(map[string]*cancelEntry)
 )
 
 func initDownloadCancel(itemID string) context.Context {
@@ -36,25 +27,10 @@ func initDownloadCancel(itemID string) context.Context {
 	cancelMu.Lock()
 	defer cancelMu.Unlock()
 
-	if entry, ok := cancelMap[itemID]; ok {
-		if entry.ctx == nil {
-			ctx, cancel := context.WithCancel(context.Background())
-			entry.ctx = ctx
-			entry.cancel = cancel
-			if entry.canceled && entry.cancel != nil {
-				entry.cancel()
-			}
-		}
-		entry.refs++
-		return entry.ctx
-	}
-
 	ctx, cancel := context.WithCancel(context.Background())
 	cancelMap[itemID] = &cancelEntry{
-		ctx:      ctx,
 		cancel:   cancel,
 		canceled: false,
-		refs:     1,
 	}
 	return ctx
 }
@@ -97,86 +73,6 @@ func clearDownloadCancel(itemID string) {
 	}
 
 	cancelMu.Lock()
-	if entry, ok := cancelMap[itemID]; ok {
-		entry.refs--
-		if entry.refs <= 0 {
-			delete(cancelMap, itemID)
-		}
-	}
+	delete(cancelMap, itemID)
 	cancelMu.Unlock()
 }
-
-func initExtensionRequestCancel(requestID string) context.Context {
-	if requestID == "" {
-		return context.Background()
-	}
-
-	extensionRequestCancelMu.Lock()
-	defer extensionRequestCancelMu.Unlock()
-
-	if entry, ok := extensionRequestCancelMap[requestID]; ok {
-		if entry.ctx == nil {
-			ctx, cancel := context.WithCancel(context.Background())
-			entry.ctx = ctx
-			entry.cancel = cancel
-			if entry.canceled && entry.cancel != nil {
-				entry.cancel()
-			}
-		}
-		entry.refs++
-		return entry.ctx
-	}
-
-	ctx, cancel := context.WithCancel(context.Background())
-	extensionRequestCancelMap[requestID] = &cancelEntry{
-		ctx:      ctx,
-		cancel:   cancel,
-		canceled: false,
-		refs:     1,
-	}
-	return ctx
-}
-
-func cancelExtensionRequest(requestID string) {
-	if requestID == "" {
-		return
-	}
-
-	extensionRequestCancelMu.Lock()
-	if entry, ok := extensionRequestCancelMap[requestID]; ok {
-		entry.canceled = true
-		if entry.cancel != nil {
-			entry.cancel()
-		}
-	} else {
-		extensionRequestCancelMap[requestID] = &cancelEntry{canceled: true}
-	}
-	extensionRequestCancelMu.Unlock()
-}
-
-func isExtensionRequestCancelled(requestID string) bool {
-	if requestID == "" {
-		return false
-	}
-
-	extensionRequestCancelMu.Lock()
-	entry, ok := extensionRequestCancelMap[requestID]
-	canceled := ok && entry.canceled
-	extensionRequestCancelMu.Unlock()
-	return canceled
-}
-
-func clearExtensionRequestCancel(requestID string) {
-	if requestID == "" {
-		return
-	}
-
-	extensionRequestCancelMu.Lock()
-	if entry, ok := extensionRequestCancelMap[requestID]; ok {
-		entry.refs--
-		if entry.refs <= 0 {
-			delete(extensionRequestCancelMap, requestID)
-		}
-	}
-	extensionRequestCancelMu.Unlock()
-}

go_backend/cover.go

@@ -19,8 +19,6 @@ var deezerSizeRegex = regexp.MustCompile(`/(\d+)x(\d+)-\d+-\d+-\d+-\d+\.jpg$`)
 
 var tidalSizeRegex = regexp.MustCompile(`/\d+x\d+\.jpg$`)
 
-var qobuzSizeRegex = regexp.MustCompile(`_\d+\.jpg$`)
-
 func convertSmallToMedium(imageURL string) string {
 	if strings.Contains(imageURL, spotifySize300) {
 		return strings.Replace(imageURL, spotifySize300, spotifySize640, 1)
@@ -137,7 +135,7 @@ func upgradeQobuzCover(coverURL string) string {
 		return coverURL
 	}
 
-	upgraded := qobuzSizeRegex.ReplaceAllString(coverURL, "_max.jpg")
+	upgraded := qobuzImageSizeRe.ReplaceAllString(coverURL, "_max.jpg")
 	if upgraded != coverURL {
 		GoLog("[Cover] Qobuz: upgraded to max resolution")
 	}

go_backend/coverage_test_helpers_test.go

@@ -1,401 +0,0 @@
-package gobackend
-
-import (
-	"archive/zip"
-	"bytes"
-	"encoding/binary"
-	"encoding/json"
-	"fmt"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-func newTestLoadedExtension(t *testing.T, types ...ExtensionType) *loadedExtension {
-	t.Helper()
-	dir := t.TempDir()
-	if err := os.WriteFile(filepath.Join(dir, "index.js"), []byte(testExtensionJS), 0600); err != nil {
-		t.Fatalf("write index.js: %v", err)
-	}
-	return &loadedExtension{
-		ID: "coverage-ext",
-		Manifest: &ExtensionManifest{
-			Name:        "coverage-ext",
-			Description: "Coverage extension",
-			Version:     "1.0.0",
-			Types:       types,
-			Permissions: ExtensionPermissions{File: true, Network: []string{"example.test"}},
-			SearchBehavior: &SearchBehaviorConfig{
-				Enabled:     true,
-				Placeholder: "Search coverage",
-				Primary:     true,
-				Icon:        "search",
-			},
-			URLHandler:    &URLHandlerConfig{Enabled: true, Patterns: []string{"https://example.test/"}},
-			TrackMatching: &TrackMatchingConfig{CustomMatching: true},
-			PostProcessing: &PostProcessingConfig{
-				Enabled: true,
-				Hooks:   []PostProcessingHook{{ID: "hook", Name: "Hook", DefaultEnabled: true, SupportedFormats: []string{"flac"}}},
-			},
-		},
-		Enabled:   true,
-		SourceDir: dir,
-		DataDir:   t.TempDir(),
-	}
-}
-
-const testExtensionJS = `
-function track(id) {
-  return {
-    id: id,
-    name: "Track " + id,
-    artists: "Artist",
-    albumName: "Album",
-    albumArtist: "Album Artist",
-    durationMs: 180000,
-    coverUrl: "https://example.test/cover.jpg",
-    releaseDate: "2026-05-04",
-    trackNumber: 1,
-    totalTracks: 10,
-    discNumber: 1,
-    totalDiscs: 1,
-    isrc: "USRC17607839",
-    itemType: "track",
-    albumType: "album",
-    tidalId: "tidal-1",
-    qobuzId: "qobuz-1",
-    deezerId: "deezer-1",
-    spotifyId: "spotify:track:1",
-    externalLinks: { tidal: "https://tidal.example/1" },
-    label: "Label",
-    copyright: "Copyright",
-    genre: "Pop",
-    composer: "Composer",
-    audioQuality: "FLAC 24-bit",
-    audioModes: "DOLBY_ATMOS"
-  };
-}
-
-registerExtension({
-  searchTracks: function(query, limit) {
-    return { tracks: [track("search-1")], total: 1 };
-  },
-  customSearch: function(query, options) {
-    var t = track("custom-1");
-    t.name = "Custom " + query;
-    return [t];
-  },
-  getHomeFeed: function() {
-    return [{ id: "home-1", title: "Home", tracks: [track("home-track")] }];
-  },
-  getBrowseCategories: function() {
-    return [{ id: "cat-1", title: "Category" }];
-  },
-  getTrack: function(id) {
-    return track(id);
-  },
-  getAlbum: function(id) {
-    return {
-      id: id,
-      name: "Album " + id,
-      artists: "Artist",
-      artistId: "artist-1",
-      coverUrl: "https://example.test/album.jpg",
-      releaseDate: "2026-05-04",
-      totalTracks: 1,
-      albumType: "album",
-      tracks: [track("album-track")]
-    };
-  },
-  getPlaylist: function(id) {
-    return {
-      id: id,
-      name: "Playlist " + id,
-      artists: "Owner",
-      coverUrl: "https://example.test/playlist.jpg",
-      totalTracks: 1,
-      tracks: [track("playlist-track")]
-    };
-  },
-  getArtist: function(id) {
-    return {
-      id: id,
-      name: "Artist",
-      imageUrl: "https://example.test/artist.jpg",
-      headerImage: "https://example.test/header.jpg",
-      listeners: 123,
-      albums: [{ id: "album-1", name: "Album", artists: "Artist", totalTracks: 1 }],
-      releases: [{ id: "release-1", name: "Release", artists: "Artist", totalTracks: 1, tracks: [track("release-track")] }],
-      topTracks: [track("top-track")]
-    };
-  },
-  enrichTrack: function(input) {
-    var t = track(input.id || "enriched");
-    t.name = "Enriched";
-    return t;
-  },
-  checkAvailability: function(isrc, name, artist, ids) {
-    return { available: true, reason: "ok", trackId: "download-track", skipFallback: true };
-  },
-  getDownloadUrl: function(id, quality) {
-    return { url: "https://example.test/audio.flac", format: "flac", bitDepth: 24, sampleRate: 96000 };
-  },
-  download: function(id, quality, outputPath, onProgress) {
-    if (onProgress) onProgress(100);
-    return {
-      success: true,
-      filePath: "EXISTS:" + outputPath,
-      alreadyExists: false,
-      bitDepth: 24,
-      sampleRate: 96000,
-      title: "Downloaded",
-      artist: "Artist",
-      album: "Album",
-      albumArtist: "Album Artist",
-      trackNumber: 1,
-      totalTracks: 10,
-      discNumber: 1,
-      totalDiscs: 1,
-      releaseDate: "2026-05-04",
-      coverUrl: "https://example.test/cover.jpg",
-      isrc: "USRC17607839",
-      genre: "Pop",
-      label: "Label",
-      copyright: "Copyright",
-      composer: "Composer",
-      lyricsLrc: "[00:00.00]Hello",
-      decryptionKey: "001122",
-      decryption: { strategy: "mp4_decryption_key", options: { kid: "1" } }
-    };
-  },
-  fetchLyrics: function(name, artist, album, duration) {
-    return { syncType: "LINE_SYNCED", provider: "coverage-ext", lines: [{ startTimeMs: 0, endTimeMs: 1000, words: "Hello" }] };
-  },
-  handleUrl: function(url) {
-    return { type: "track", name: "Handled", coverUrl: "https://example.test/cover.jpg", track: track("url-track"), tracks: [track("url-track")], album: this.getAlbum("url-album"), artist: this.getArtist("url-artist") };
-  },
-  matchTrack: function(req) {
-    return { matched: true, trackId: "download-track", confidence: 0.95, reason: "exact" };
-  },
-  postProcess: function(path, req) {
-    return { success: true, newFilePath: path, bitDepth: 24, sampleRate: 96000 };
-  },
-  postProcessV2: function(input, metadata, hookId) {
-    return { success: true, newFilePath: input.path || input.uri, newFileUri: input.uri || "", bitDepth: 24, sampleRate: 96000 };
-  }
-});
-`
-
-func mustReadFile(t *testing.T, path string) []byte {
-	t.Helper()
-	data, err := os.ReadFile(path)
-	if err != nil {
-		t.Fatalf("read file: %v", err)
-	}
-	return data
-}
-
-func buildID3v23Tag(frames ...[]byte) []byte {
-	body := bytes.Join(frames, nil)
-	header := []byte{'I', 'D', '3', 3, 0, 0, 0, 0, 0, 0}
-	copy(header[6:10], syncsafeBytes(len(body)))
-	return append(header, body...)
-}
-
-func id3TextFrame(id, value string) []byte {
-	return id3v23Frame(id, append([]byte{3}, []byte(value)...))
-}
-
-func id3CommentFrame(id, value string) []byte {
-	payload := append([]byte{3, 'e', 'n', 'g', 0}, []byte(value)...)
-	return id3v23Frame(id, payload)
-}
-
-func id3UserTextFrame(id, desc, value string) []byte {
-	payload := append([]byte{3}, []byte(desc)...)
-	payload = append(payload, 0)
-	payload = append(payload, []byte(value)...)
-	return id3v23Frame(id, payload)
-}
-
-func id3v23Frame(id string, payload []byte) []byte {
-	frame := make([]byte, 10+len(payload))
-	copy(frame[0:4], id)
-	binary.BigEndian.PutUint32(frame[4:8], uint32(len(payload)))
-	copy(frame[10:], payload)
-	return frame
-}
-
-func buildID3v22Tag(frames ...[]byte) []byte {
-	body := bytes.Join(frames, nil)
-	header := []byte{'I', 'D', '3', 2, 0, 0, 0, 0, 0, 0}
-	copy(header[6:10], syncsafeBytes(len(body)))
-	return append(header, body...)
-}
-
-func id3v22TextFrame(id, value string) []byte {
-	return id3v22Frame(id, append([]byte{3}, []byte(value)...))
-}
-
-func id3v22CommentFrame(id, value string) []byte {
-	payload := append([]byte{3, 'e', 'n', 'g', 0}, []byte(value)...)
-	return id3v22Frame(id, payload)
-}
-
-func id3v22Frame(id string, payload []byte) []byte {
-	frame := make([]byte, 6+len(payload))
-	copy(frame[0:3], id)
-	size := len(payload)
-	frame[3] = byte(size >> 16)
-	frame[4] = byte(size >> 8)
-	frame[5] = byte(size)
-	copy(frame[6:], payload)
-	return frame
-}
-
-func syncsafeBytes(size int) []byte {
-	return []byte{
-		byte((size >> 21) & 0x7f),
-		byte((size >> 14) & 0x7f),
-		byte((size >> 7) & 0x7f),
-		byte(size & 0x7f),
-	}
-}
-
-func buildID3v1Tag(title, artist, album, year string, track, genre byte) []byte {
-	tag := make([]byte, 128)
-	copy(tag[0:3], "TAG")
-	copyPadded(tag[3:33], title)
-	copyPadded(tag[33:63], artist)
-	copyPadded(tag[63:93], album)
-	copyPadded(tag[93:97], year)
-	tag[125] = 0
-	tag[126] = track
-	tag[127] = genre
-	return tag
-}
-
-func copyPadded(dst []byte, value string) {
-	for i := range dst {
-		dst[i] = ' '
-	}
-	copy(dst, value)
-}
-
-func writeExportCueFixture(t *testing.T, dir string) (string, string) {
-	t.Helper()
-	audioPath := filepath.Join(dir, "exports.wav")
-	if err := os.WriteFile(audioPath, []byte("audio"), 0600); err != nil {
-		t.Fatalf("write export audio: %v", err)
-	}
-	cuePath := filepath.Join(dir, "exports.cue")
-	cue := "PERFORMER \"Artist\"\nTITLE \"Album\"\nFILE \"exports.wav\" WAVE\n  TRACK 01 AUDIO\n    TITLE \"Song\"\n    INDEX 01 00:00:00\n"
-	if err := os.WriteFile(cuePath, []byte(cue), 0600); err != nil {
-		t.Fatalf("write export cue: %v", err)
-	}
-	return cuePath, audioPath
-}
-
-func escapeJSONPath(path string) string {
-	data, _ := json.Marshal(path)
-	return strings.Trim(string(data), `"`)
-}
-
-func fakeDeezerResponse(path, rawQuery string) string {
-	switch {
-	case path == "/2.0/search/track":
-		if strings.Contains(rawQuery, "MISSING") {
-			return `{"data":[]}`
-		}
-		return `{"data":[` + fakeDeezerTrackJSON(101, true) + `]}`
-	case path == "/2.0/search/artist":
-		return `{"data":[{"id":301,"name":"Artist","picture_xl":"artist-xl","nb_fan":123}]}`
-	case path == "/2.0/search/album":
-		return `{"data":[{"id":201,"title":"Album","cover_xl":"album-xl","nb_tracks":2,"release_date":"2026-05-04","record_type":"compile","artist":{"id":301,"name":"Artist"}}]}`
-	case path == "/2.0/search/playlist":
-		return `{"data":[{"id":401,"title":"Playlist","picture_xl":"playlist-xl","nb_tracks":2,"user":{"name":"Owner"}}]}`
-	case path == "/2.0/track/101", path == "/2.0/track/isrc:USRC17607839":
-		return fakeDeezerTrackJSON(101, true)
-	case path == "/2.0/track/102":
-		return fakeDeezerTrackJSON(102, true)
-	case path == "/2.0/track/isrc:MISSING":
-		return `{"id":0}`
-	case path == "/2.0/album/201":
-		return `{"id":201,"title":"Album","cover_xl":"album-xl","release_date":"2026-05-04","nb_tracks":2,"record_type":"compile","label":"Label","copyright":"Copyright","genres":{"data":[{"name":"Pop"},{"name":"Dance"}]},"artist":{"id":301,"name":"Album Artist"},"contributors":[{"name":"Contributor A"},{"name":"Contributor B"}],"tracks":{"data":[` + fakeDeezerTrackJSON(101, true) + `,` + fakeDeezerTrackJSON(102, false) + `]}}`
-	case path == "/2.0/artist/301":
-		return `{"id":301,"name":"Artist","picture_xl":"artist-xl","nb_fan":123,"nb_album":1}`
-	case path == "/2.0/artist/301/albums":
-		return `{"data":[{"id":201,"title":"Album","release_date":"2026-05-04","nb_tracks":0,"cover_xl":"album-xl","record_type":"compile"}]}`
-	case path == "/2.0/artist/301/related":
-		return `{"data":[{"id":302,"name":"Related","picture_xl":"related-xl","nb_fan":10}]}`
-	case path == "/2.0/playlist/401":
-		return `{"id":401,"title":"Playlist","picture_xl":"playlist-xl","nb_tracks":2,"creator":{"name":"Owner"},"tracks":{"data":[` + fakeDeezerTrackJSON(101, true) + `,` + fakeDeezerTrackJSON(102, false) + `]}}`
-	default:
-		return ""
-	}
-}
-
-func fakeDeezerTrackJSON(id int, withISRC bool) string {
-	isrc := ""
-	if withISRC {
-		isrc = `,"isrc":"USRC17607839"`
-		if id == 102 {
-			isrc = `,"isrc":"USRC17607840"`
-		}
-	}
-	return fmt.Sprintf(`{"id":%d,"title":"Track %d","duration":180,"track_position":%d,"disk_number":1%s,"link":"https://deezer.test/track/%d","release_date":"2026-05-04","artist":{"id":301,"name":"Artist"},"contributors":[{"name":"Contributor A"},{"name":"Contributor B"}],"album":{"id":201,"title":"Album","cover_xl":"album-xl","release_date":"2026-05-04","record_type":"album"}}`, id, id, id-100, isrc, id)
-}
-
-func createTestExtensionPackage(t *testing.T, path, name, version, js string, extraFiles map[string]string) {
-	t.Helper()
-	out, err := os.Create(path)
-	if err != nil {
-		t.Fatalf("create extension package: %v", err)
-	}
-	defer out.Close()
-
-	zw := zip.NewWriter(out)
-	defer zw.Close()
-
-	manifest := fmt.Sprintf(`{
-		"name": %q,
-		"displayName": %q,
-		"version": %q,
-		"description": "Packaged test extension",
-		"type": ["metadata_provider", "download_provider", "lyrics_provider"],
-		"permissions": {"network": ["example.test"], "storage": true, "file": true},
-		"icon": "icon.png",
-		"settings": [{"key":"quality","type":"string","label":"Quality"}],
-		"qualityOptions": [{"id":"lossless","label":"Lossless","description":"Lossless"}],
-		"searchBehavior": {"enabled": true, "placeholder": "Search", "primary": true},
-		"urlHandler": {"enabled": true, "patterns": ["https://example.test/"]},
-		"trackMatching": {"customMatching": true},
-		"postProcessing": {"enabled": true, "hooks": [{"id":"hook","name":"Hook"}]},
-		"serviceHealth": [{"id":"main","url":"https://example.test/health"}],
-		"capabilities": {"homeFeed": true}
-	}`, name, name, version)
-
-	for fileName, content := range map[string]string{
-		"manifest.json": manifest,
-		"index.js":      js,
-		"icon.png":      "png",
-	} {
-		writer, err := zw.Create(fileName)
-		if err != nil {
-			t.Fatalf("zip create %s: %v", fileName, err)
-		}
-		if _, err := writer.Write([]byte(content)); err != nil {
-			t.Fatalf("zip write %s: %v", fileName, err)
-		}
-	}
-	for fileName, content := range extraFiles {
-		writer, err := zw.Create(fileName)
-		if err != nil {
-			t.Fatalf("zip create extra %s: %v", fileName, err)
-		}
-		if _, err := writer.Write([]byte(content)); err != nil {
-			t.Fatalf("zip write extra %s: %v", fileName, err)
-		}
-	}
-}

go_backend/cue_duplicate_supplement_test.go

@@ -1,171 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"testing"
-	"time"
-)
-
-func TestCueParserEndToEnd(t *testing.T) {
-	dir := t.TempDir()
-	audioPath := filepath.Join(dir, "album.wav")
-	if err := os.WriteFile(audioPath, []byte("audio"), 0600); err != nil {
-		t.Fatalf("write audio: %v", err)
-	}
-	cuePath := filepath.Join(dir, "album.cue")
-	cue := "\ufeffREM GENRE \"Pop\"\n" +
-		"REM DATE 2026\n" +
-		"REM COMMENT \"comment\"\n" +
-		"REM COMPOSER \"Album Composer\"\n" +
-		"PERFORMER \"Album Artist\"\n" +
-		"TITLE \"Album Title\"\n" +
-		"FILE \"album.wav\" WAVE\n" +
-		"  TRACK 01 AUDIO\n" +
-		"    TITLE \"First\"\n" +
-		"    PERFORMER \"Track Artist\"\n" +
-		"    ISRC USRC17607839\n" +
-		"    INDEX 01 00:00:00\n" +
-		"  TRACK 02 AUDIO\n" +
-		"    TITLE \"Second\"\n" +
-		"    SONGWRITER \"Track Composer\"\n" +
-		"    INDEX 00 03:00:00\n" +
-		"    INDEX 01 03:05:00\n"
-	if err := os.WriteFile(cuePath, []byte(cue), 0600); err != nil {
-		t.Fatalf("write cue: %v", err)
-	}
-
-	sheet, err := ParseCueFile(cuePath)
-	if err != nil {
-		t.Fatalf("ParseCueFile: %v", err)
-	}
-	if sheet.Performer != "Album Artist" || sheet.Title != "Album Title" || len(sheet.Tracks) != 2 {
-		t.Fatalf("sheet = %#v", sheet)
-	}
-	if got := parseCueTimestamp("01:02:37"); got <= 62 || got >= 63 {
-		t.Fatalf("timestamp = %f", got)
-	}
-	if got := formatCueTimestamp(3723.5); got != "01:02:03.500" {
-		t.Fatalf("format timestamp = %q", got)
-	}
-	if got := unquoteCue("  \"quoted\"  "); got != "quoted" {
-		t.Fatalf("unquote = %q", got)
-	}
-	fileName, fileType := parseCueFileLine("unquoted album.flac FLAC")
-	if fileName != "unquoted album.flac" || fileType != "FLAC" {
-		t.Fatalf("file line = %q/%q", fileName, fileType)
-	}
-
-	if resolved := ResolveCueAudioPath(cuePath, "album.flac"); resolved != audioPath {
-		t.Fatalf("resolved = %q want %q", resolved, audioPath)
-	}
-	info, err := BuildCueSplitInfo(cuePath, sheet, "")
-	if err != nil {
-		t.Fatalf("BuildCueSplitInfo: %v", err)
-	}
-	if info.Tracks[0].EndSec != 180 || info.Tracks[1].Composer != "Track Composer" {
-		t.Fatalf("split info = %#v", info.Tracks)
-	}
-
-	jsonText, err := ParseCueFileJSON(cuePath, "")
-	if err != nil {
-		t.Fatalf("ParseCueFileJSON: %v", err)
-	}
-	var decoded CueSplitInfo
-	if err := json.Unmarshal([]byte(jsonText), &decoded); err != nil {
-		t.Fatalf("decode cue json: %v", err)
-	}
-	if decoded.AudioPath != audioPath {
-		t.Fatalf("decoded audio path = %q", decoded.AudioPath)
-	}
-
-	results, err := ScanCueFileForLibraryExt(cuePath, "", "virtual/album.cue", 1234, "scan-time")
-	if err != nil {
-		t.Fatalf("ScanCueFileForLibraryExt: %v", err)
-	}
-	if len(results) != 2 || results[0].TrackName != "First" || results[0].Duration != 180 {
-		t.Fatalf("scan results = %#v", results)
-	}
-	if results[0].FilePath != "virtual/album.cue#track01" || results[0].Format != "cue+wav" {
-		t.Fatalf("scan path/format = %q/%q", results[0].FilePath, results[0].Format)
-	}
-
-	if _, err := ParseCueFile(filepath.Join(dir, "missing.cue")); err == nil {
-		t.Fatal("expected missing cue error")
-	}
-	emptyCue := filepath.Join(dir, "empty.cue")
-	if err := os.WriteFile(emptyCue, []byte("TITLE \"No tracks\""), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := ParseCueFile(emptyCue); err == nil {
-		t.Fatal("expected no tracks error")
-	}
-	missingDir := t.TempDir()
-	missingCuePath := filepath.Join(missingDir, "missing.cue")
-	if err := os.WriteFile(missingCuePath, []byte(cue), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := BuildCueSplitInfo(missingCuePath, &CueSheet{FileName: "missing.wav"}, ""); err == nil {
-		t.Fatal("expected missing audio error")
-	}
-	if _, err := resolveCueAudioPathForLibrary(cuePath, nil, ""); err == nil {
-		t.Fatal("expected nil sheet error")
-	}
-	if _, err := scanCueSheetForLibrary(cuePath, nil, audioPath, "", 0, "", ""); err == nil {
-		t.Fatal("expected nil scan sheet error")
-	}
-}
-
-func TestDuplicateIndexAndParallelExistence(t *testing.T) {
-	dir := t.TempDir()
-	filePath := filepath.Join(dir, "song.flac")
-	if err := os.WriteFile(filePath, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-
-	idx := &ISRCIndex{index: map[string]string{}, outputDir: dir, buildTime: time.Now()}
-	idx.Add("usrc17607839", filePath)
-	if got, ok := idx.lookup("USRC17607839"); !ok || got != filePath {
-		t.Fatalf("lookup = %q/%v", got, ok)
-	}
-	if got, err := idx.Lookup("usrc17607839"); err != nil || got != filePath {
-		t.Fatalf("Lookup = %q/%v", got, err)
-	}
-	idx.remove("usrc17607839")
-	if _, ok := idx.lookup("usrc17607839"); ok {
-		t.Fatal("expected removed ISRC")
-	}
-
-	isrcIndexCacheMu.Lock()
-	isrcIndexCache[dir] = idx
-	isrcIndexCacheMu.Unlock()
-	defer InvalidateISRCCache(dir)
-
-	AddToISRCIndex(dir, "USRC17607839", filePath)
-	if found, err := CheckISRCExists(dir, "USRC17607839"); err != nil || found != filePath {
-		t.Fatalf("CheckISRCExists = %q/%v", found, err)
-	}
-	if !CheckFileExists(filePath) || CheckFileExists(dir) || CheckFileExists(filepath.Join(dir, "missing.flac")) {
-		t.Fatal("unexpected file existence result")
-	}
-
-	tracksJSON := `[{"isrc":"USRC17607839","track_name":"Song","artist_name":"Artist"},{"isrc":"MISSING","track_name":"Other","artist_name":"Artist"}]`
-	resultJSON, err := CheckFilesExistParallel(dir, tracksJSON)
-	if err != nil {
-		t.Fatalf("CheckFilesExistParallel: %v", err)
-	}
-	var results []FileExistenceResult
-	if err := json.Unmarshal([]byte(resultJSON), &results); err != nil {
-		t.Fatalf("decode results: %v", err)
-	}
-	if !results[0].Exists || results[0].FilePath != filePath || results[1].Exists {
-		t.Fatalf("results = %#v", results)
-	}
-	if _, err := CheckFilesExistParallel(dir, `not-json`); err == nil {
-		t.Fatal("expected invalid json error")
-	}
-	if err := PreBuildISRCIndex(""); err == nil {
-		t.Fatal("expected empty dir error")
-	}
-}

go_backend/cue_parser.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 )
 
+// CueSheet represents a parsed .cue file
 type CueSheet struct {
 	Performer string     `json:"performer"`
 	Title     string     `json:"title"`
@@ -23,6 +24,7 @@ type CueSheet struct {
 	Tracks    []CueTrack `json:"tracks"`
 }
 
+// CueTrack represents a single track in a cue sheet
 type CueTrack struct {
 	Number    int     `json:"number"`
 	Title     string  `json:"title"`
@@ -33,6 +35,7 @@ type CueTrack struct {
 	PreGap    float64 `json:"pre_gap"`    // INDEX 00 in seconds (or -1 if not present)
 }
 
+// CueSplitInfo represents the information needed to split a CUE+audio file
 type CueSplitInfo struct {
 	CuePath   string          `json:"cue_path"`
 	AudioPath string          `json:"audio_path"`
@@ -43,6 +46,7 @@ type CueSplitInfo struct {
 	Tracks    []CueSplitTrack `json:"tracks"`
 }
 
+// CueSplitTrack has the FFmpeg split parameters for a single track
 type CueSplitTrack struct {
 	Number   int     `json:"number"`
 	Title    string  `json:"title"`
@@ -58,6 +62,7 @@ var (
 	reQuoted     = regexp.MustCompile(`"([^"]*)"`)
 )
 
+// ParseCueFile parses a .cue file and returns a CueSheet
 func ParseCueFile(cuePath string) (*CueSheet, error) {
 	f, err := os.Open(cuePath)
 	if err != nil {
@@ -197,6 +202,7 @@ func ParseCueFile(cuePath string) (*CueSheet, error) {
 	return sheet, nil
 }
 
+// parseCueTimestamp converts MM:SS:FF (frames at 75fps) to seconds
 func parseCueTimestamp(ts string) float64 {
 	parts := strings.Split(ts, ":")
 	if len(parts) != 3 {
@@ -210,6 +216,7 @@ func parseCueTimestamp(ts string) float64 {
 	return float64(minutes)*60 + float64(seconds) + float64(frames)/75.0
 }
 
+// formatCueTimestamp converts seconds to HH:MM:SS.mmm format for FFmpeg
 func formatCueTimestamp(seconds float64) string {
 	if seconds < 0 {
 		return "0"
@@ -220,6 +227,7 @@ func formatCueTimestamp(seconds float64) string {
 	return fmt.Sprintf("%02d:%02d:%06.3f", hours, mins, secs)
 }
 
+// unquoteCue removes surrounding quotes from a CUE value
 func unquoteCue(s string) string {
 	s = strings.TrimSpace(s)
 	if matches := reQuoted.FindStringSubmatch(s); len(matches) == 2 {
@@ -228,12 +236,14 @@ func unquoteCue(s string) string {
 	return s
 }
 
+// parseCueFileLine parses the FILE command's filename and type
 func parseCueFileLine(rest string) (string, string) {
 	rest = strings.TrimSpace(rest)
 
 	var filename, ftype string
 
 	if strings.HasPrefix(rest, "\"") {
+		// Quoted filename
 		endQuote := strings.Index(rest[1:], "\"")
 		if endQuote >= 0 {
 			filename = rest[1 : endQuote+1]
@@ -243,6 +253,7 @@ func parseCueFileLine(rest string) (string, string) {
 			filename = rest
 		}
 	} else {
+		// Unquoted filename - last word is the type
 		parts := strings.Fields(rest)
 		if len(parts) >= 2 {
 			ftype = parts[len(parts)-1]
@@ -255,14 +266,18 @@ func parseCueFileLine(rest string) (string, string) {
 	return filename, strings.TrimSpace(ftype)
 }
 
+// ResolveCueAudioPath finds the actual audio file referenced by a .cue sheet.
+// It checks relative to the cue file's directory.
 func ResolveCueAudioPath(cuePath string, cueFileName string) string {
 	cueDir := filepath.Dir(cuePath)
 
+	// 1. Try the exact filename from the .cue
 	candidate := filepath.Join(cueDir, cueFileName)
 	if _, err := os.Stat(candidate); err == nil {
 		return candidate
 	}
 
+	// 2. Try common case variations
 	baseName := strings.TrimSuffix(cueFileName, filepath.Ext(cueFileName))
 	commonExts := []string{".flac", ".wav", ".ape", ".mp3", ".ogg", ".wv", ".m4a"}
 	for _, ext := range commonExts {
@@ -270,12 +285,14 @@ func ResolveCueAudioPath(cuePath string, cueFileName string) string {
 		if _, err := os.Stat(candidate); err == nil {
 			return candidate
 		}
+		// Try uppercase ext
 		candidate = filepath.Join(cueDir, baseName+strings.ToUpper(ext))
 		if _, err := os.Stat(candidate); err == nil {
 			return candidate
 		}
 	}
 
+	// 3. Try to find any audio file with the same base name as the .cue file
 	cueBase := strings.TrimSuffix(filepath.Base(cuePath), filepath.Ext(cuePath))
 	for _, ext := range commonExts {
 		candidate = filepath.Join(cueDir, cueBase+ext)
@@ -284,6 +301,7 @@ func ResolveCueAudioPath(cuePath string, cueFileName string) string {
 		}
 	}
 
+	// 4. If there's only one audio file in the directory, use that
 	entries, err := os.ReadDir(cueDir)
 	if err == nil {
 		audioExts := map[string]bool{
@@ -308,9 +326,13 @@ func ResolveCueAudioPath(cuePath string, cueFileName string) string {
 	return ""
 }
 
+// BuildCueSplitInfo creates the split information from a parsed CUE sheet.
+// This is returned to the Dart side so FFmpeg can perform the splitting.
+// audioDir, if non-empty, overrides the directory for audio file resolution.
 func BuildCueSplitInfo(cuePath string, sheet *CueSheet, audioDir string) (*CueSplitInfo, error) {
 	resolveDir := cuePath
 	if audioDir != "" {
+		// Create a virtual path in audioDir so ResolveCueAudioPath looks there
 		resolveDir = filepath.Join(audioDir, filepath.Base(cuePath))
 	}
 	audioPath := ResolveCueAudioPath(resolveDir, sheet.FileName)
@@ -338,9 +360,11 @@ func BuildCueSplitInfo(cuePath string, sheet *CueSheet, audioDir string) (*CueSp
 			composer = sheet.Composer
 		}
 
+		// End time is the start of the next track, or -1 for the last track
 		endSec := float64(-1)
 		if i+1 < len(sheet.Tracks) {
 			nextTrack := sheet.Tracks[i+1]
+			// Use pre-gap of next track if available, otherwise its start time
 			if nextTrack.PreGap >= 0 {
 				endSec = nextTrack.PreGap
 			} else {
@@ -362,6 +386,11 @@ func BuildCueSplitInfo(cuePath string, sheet *CueSheet, audioDir string) (*CueSp
 	return info, nil
 }
 
+// ParseCueFileJSON parses a .cue file and returns JSON with split info.
+// This is the main entry point called from Dart via the platform bridge.
+// audioDir, if non-empty, overrides the directory used for resolving the
+// referenced audio file (useful when the .cue was copied to a temp dir
+// but the audio still lives in the original location, e.g. SAF).
 func ParseCueFileJSON(cuePath string, audioDir string) (string, error) {
 	sheet, err := ParseCueFile(cuePath)
 	if err != nil {
@@ -381,6 +410,9 @@ func ParseCueFileJSON(cuePath string, audioDir string) (string, error) {
 	return string(jsonBytes), nil
 }
 
+// ScanCueFileForLibrary parses a .cue file and returns multiple LibraryScanResult
+// entries, one per track. This is used by the library scanner to populate the
+// library with individual track entries from a single CUE+FLAC album.
 func ScanCueFileForLibrary(cuePath string, scanTime string) ([]LibraryScanResult, error) {
 	sheet, err := ParseCueFile(cuePath)
 	if err != nil {
@@ -393,6 +425,13 @@ func ScanCueFileForLibrary(cuePath string, scanTime string) ([]LibraryScanResult
 	return scanCueSheetForLibrary(cuePath, sheet, audioPath, "", 0, "", scanTime)
 }
 
+// ScanCueFileForLibraryExt is like ScanCueFileForLibrary but with extra parameters
+// for SAF (Storage Access Framework) scenarios:
+//   - audioDir: if non-empty, overrides the directory used to find the audio file
+//   - virtualPathPrefix: if non-empty, used instead of cuePath as the base for
+//     virtual file paths (e.g. a content:// URI). IDs are also based on this.
+//   - fileModTime: if > 0, used as the FileModTime for all results instead of
+//     stat-ing the cuePath on disk (useful when the real file lives behind SAF)
 func ScanCueFileForLibraryExt(cuePath, audioDir, virtualPathPrefix string, fileModTime int64, scanTime string) ([]LibraryScanResult, error) {
 	return ScanCueFileForLibraryExtWithCoverCacheKey(
 		cuePath,
@@ -444,6 +483,7 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 		return nil, fmt.Errorf("cue sheet is nil for %s", cuePath)
 	}
 
+	// Try to get quality info from the audio file
 	var bitDepth, sampleRate int
 	var totalDurationSec float64
 	audioExt := strings.ToLower(filepath.Ext(audioPath))
@@ -465,6 +505,7 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 		}
 	}
 
+	// Extract cover from audio file for all tracks
 	var coverPath string
 	libraryCoverCacheMu.RLock()
 	coverCacheDir := libraryCoverCacheDir
@@ -481,11 +522,13 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 		}
 	}
 
+	// Determine the base path for virtual paths and IDs
 	pathBase := cuePath
 	if virtualPathPrefix != "" {
 		pathBase = virtualPathPrefix
 	}
 
+	// Determine fileModTime
 	modTime := fileModTime
 	if modTime <= 0 {
 		if info, err := os.Stat(cuePath); err == nil {
@@ -513,11 +556,7 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 			album = "Unknown Album"
 		}
 
-		composer := track.Composer
-		if composer == "" {
-			composer = sheet.Composer
-		}
-
+		// Calculate duration for this track
 		var duration int
 		if i+1 < len(sheet.Tracks) {
 			nextStart := sheet.Tracks[i+1].StartTime
@@ -531,6 +570,9 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 
 		id := generateLibraryID(fmt.Sprintf("%s#track%d", pathBase, track.Number))
 
+		// Use a virtual file path that includes the track number to ensure
+		// uniqueness in the database (file_path has a UNIQUE constraint).
+		// Format: /path/to/album.cue#track01 or content://...album.cue#track01
 		virtualFilePath := fmt.Sprintf("%s#track%02d", pathBase, track.Number)
 
 		result := LibraryScanResult{
@@ -544,15 +586,12 @@ func scanCueSheetForLibrary(cuePath string, sheet *CueSheet, audioPath, virtualP
 			ScannedAt:   scanTime,
 			ISRC:        track.ISRC,
 			TrackNumber: track.Number,
-			TotalTracks: len(sheet.Tracks),
 			DiscNumber:  1,
-			TotalDiscs:  1,
 			Duration:    duration,
 			ReleaseDate: sheet.Date,
 			BitDepth:    bitDepth,
 			SampleRate:  sampleRate,
 			Genre:       sheet.Genre,
-			Composer:    composer,
 			Format:      "cue+" + strings.TrimPrefix(audioExt, "."),
 		}
 

go_backend/deezer.go

@@ -196,22 +196,15 @@ type deezerAlbumSimple struct {
 	RecordType  string `json:"record_type"`
 }
 
-// deezerTrackArtistDisplay returns the display artist string for a track,
-// preferring the Contributors list (comma-joined) when available, falling
-// back to the primary Artist.Name.
-func deezerTrackArtistDisplay(track deezerTrack) string {
+func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
+	artistName := track.Artist.Name
 	if len(track.Contributors) > 0 {
 		names := make([]string, len(track.Contributors))
 		for i, a := range track.Contributors {
 			names[i] = a.Name
 		}
-		return strings.Join(names, ", ")
+		artistName = strings.Join(names, ", ")
 	}
-	return track.Artist.Name
-}
-
-func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
-	artistName := deezerTrackArtistDisplay(track)
 
 	albumImage := track.Album.CoverXL
 	if albumImage == "" {
@@ -630,12 +623,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 	}
 
 	isrcMap := c.fetchISRCsParallel(ctx, allTracks)
-	totalDiscs := 0
-	for _, track := range allTracks {
-		if track.DiskNumber > totalDiscs {
-			totalDiscs = track.DiskNumber
-		}
-	}
 
 	tracks := make([]AlbumTrackMetadata, 0, len(allTracks))
 	albumType := album.RecordType
@@ -654,7 +641,7 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 
 		tracks = append(tracks, AlbumTrackMetadata{
 			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
-			Artists:     deezerTrackArtistDisplay(track),
+			Artists:     track.Artist.Name,
 			Name:        track.Title,
 			AlbumName:   album.Title,
 			AlbumArtist: artistName,
@@ -664,7 +651,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 			TrackNumber: trackNum,
 			TotalTracks: album.NbTracks,
 			DiscNumber:  track.DiskNumber,
-			TotalDiscs:  totalDiscs,
 			ExternalURL: track.Link,
 			ISRC:        isrc,
 			AlbumID:     fmt.Sprintf("deezer:%d", album.ID),
@@ -755,10 +741,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 				Artists:     artist.Name,
 			})
 		}
-
-		// The Deezer /artist/{id}/albums endpoint does not return nb_tracks.
-		// Fetch track counts in parallel from individual /album/{id} endpoints.
-		c.fetchAlbumTrackCounts(ctx, albums)
 	}
 
 	result := &ArtistResponsePayload{
@@ -778,63 +760,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 	return result, nil
 }
 
-// fetchAlbumTrackCounts fetches nb_tracks for each album in parallel using
-// individual /album/{id} calls, since the /artist/{id}/albums endpoint does
-// not include this field. Albums whose track count is already known (non-zero)
-// are skipped.
-func (c *DeezerClient) fetchAlbumTrackCounts(ctx context.Context, albums []ArtistAlbumMetadata) {
-	// Find albums that need track counts
-	type indexedID struct {
-		idx     int
-		albumID string
-	}
-	var toFetch []indexedID
-	for i, a := range albums {
-		if a.TotalTracks == 0 {
-			rawID := strings.TrimPrefix(a.ID, "deezer:")
-			if rawID != "" {
-				toFetch = append(toFetch, indexedID{idx: i, albumID: rawID})
-			}
-		}
-	}
-	if len(toFetch) == 0 {
-		return
-	}
-
-	const maxParallel = 10
-	sem := make(chan struct{}, maxParallel)
-	var mu sync.Mutex
-	var wg sync.WaitGroup
-
-	for _, item := range toFetch {
-		wg.Add(1)
-		go func(it indexedID) {
-			defer wg.Done()
-
-			select {
-			case sem <- struct{}{}:
-				defer func() { <-sem }()
-			case <-ctx.Done():
-				return
-			}
-
-			albumURL := fmt.Sprintf(deezerAlbumURL, it.albumID)
-			var resp struct {
-				NbTracks int `json:"nb_tracks"`
-			}
-			if err := c.getJSON(ctx, albumURL, &resp); err != nil {
-				return
-			}
-
-			mu.Lock()
-			albums[it.idx].TotalTracks = resp.NbTracks
-			mu.Unlock()
-		}(item)
-	}
-
-	wg.Wait()
-}
-
 func (c *DeezerClient) GetRelatedArtists(ctx context.Context, artistID string, limit int) ([]SearchArtistResult, error) {
 	normalizedArtistID := strings.TrimSpace(strings.TrimPrefix(artistID, "deezer:"))
 	if normalizedArtistID == "" {
@@ -967,7 +892,7 @@ func (c *DeezerClient) GetPlaylist(ctx context.Context, playlistID string) (*Pla
 
 		tracks = append(tracks, AlbumTrackMetadata{
 			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
-			Artists:     deezerTrackArtistDisplay(track),
+			Artists:     track.Artist.Name,
 			Name:        track.Title,
 			AlbumName:   track.Album.Title,
 			AlbumArtist: track.Artist.Name,

go_backend/deezer_download.go

@@ -0,0 +1,608 @@
+package gobackend
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const deezerYoinkifyURL = "https://yoinkify.lol/api/download"
+const deezerMusicDLURL = "https://www.musicdl.me/api/download"
+
+type YoinkifyRequest struct {
+	URL         string `json:"url"`
+	Format      string `json:"format"`
+	GenreSource string `json:"genreSource"`
+}
+
+type DeezerDownloadResult struct {
+	FilePath    string
+	BitDepth    int
+	SampleRate  int
+	Title       string
+	Artist      string
+	Album       string
+	ReleaseDate string
+	TrackNumber int
+	DiscNumber  int
+	ISRC        string
+	LyricsLRC   string
+}
+
+func resolveSpotifyURLForYoinkify(req DownloadRequest) (string, error) {
+	rawSpotify := strings.TrimSpace(req.SpotifyID)
+	if rawSpotify != "" {
+		if isLikelySpotifyTrackID(rawSpotify) {
+			return fmt.Sprintf("https://open.spotify.com/track/%s", rawSpotify), nil
+		}
+
+		if parsed, err := parseSpotifyURI(rawSpotify); err == nil && parsed.Type == "track" && parsed.ID != "" {
+			return fmt.Sprintf("https://open.spotify.com/track/%s", parsed.ID), nil
+		}
+	}
+
+	deezerID := strings.TrimSpace(req.DeezerID)
+	if deezerID == "" {
+		if prefixed, found := strings.CutPrefix(rawSpotify, "deezer:"); found {
+			deezerID = strings.TrimSpace(prefixed)
+		}
+	}
+
+	if deezerID != "" {
+		songlink := NewSongLinkClient()
+		spotifyID, err := songlink.GetSpotifyIDFromDeezer(deezerID)
+		if err != nil {
+			return "", fmt.Errorf("failed to map deezer:%s to Spotify ID: %w", deezerID, err)
+		}
+		spotifyID = strings.TrimSpace(spotifyID)
+		if spotifyID == "" {
+			return "", fmt.Errorf("SongLink returned empty Spotify ID for deezer:%s", deezerID)
+		}
+		return fmt.Sprintf("https://open.spotify.com/track/%s", spotifyID), nil
+	}
+
+	return "", fmt.Errorf("missing Spotify track ID for Deezer Yoinkify")
+}
+
+func isLikelySpotifyTrackID(value string) bool {
+	if len(value) != 22 {
+		return false
+	}
+	for _, r := range value {
+		switch {
+		case r >= 'A' && r <= 'Z':
+		case r >= 'a' && r <= 'z':
+		case r >= '0' && r <= '9':
+		default:
+			return false
+		}
+	}
+	return true
+}
+
+func (c *DeezerClient) DownloadFromYoinkify(spotifyURL, outputPath string, outputFD int, itemID string) error {
+	payload := YoinkifyRequest{
+		URL:         spotifyURL,
+		Format:      "flac",
+		GenreSource: "spotify",
+	}
+
+	jsonData, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("failed to encode Yoinkify request: %w", err)
+	}
+
+	ctx := context.Background()
+	if itemID != "" {
+		StartItemProgress(itemID)
+		defer CompleteItemProgress(itemID)
+		ctx = initDownloadCancel(itemID)
+		defer clearDownloadCancel(itemID)
+	}
+
+	if isDownloadCancelled(itemID) {
+		return ErrDownloadCancelled
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, deezerYoinkifyURL, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return fmt.Errorf("failed to create Yoinkify request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "*/*")
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	resp, err := GetDownloadClient().Do(req)
+	if err != nil {
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
+		return fmt.Errorf("failed to call Yoinkify: %w", err)
+	}
+	defer resp.Body.Close()
+
+	contentType := strings.ToLower(strings.TrimSpace(resp.Header.Get("Content-Type")))
+	if resp.StatusCode != http.StatusOK {
+		bodyBytes, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		bodyText := strings.TrimSpace(string(bodyBytes))
+		if bodyText != "" {
+			return fmt.Errorf("Yoinkify returned status %d: %s", resp.StatusCode, bodyText)
+		}
+		return fmt.Errorf("Yoinkify returned status %d", resp.StatusCode)
+	}
+
+	if strings.Contains(contentType, "application/json") {
+		bodyBytes, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		bodyText := strings.TrimSpace(string(bodyBytes))
+		if bodyText == "" {
+			bodyText = "empty JSON payload"
+		}
+		return fmt.Errorf("Yoinkify returned JSON instead of audio: %s", bodyText)
+	}
+
+	expectedSize := resp.ContentLength
+	if expectedSize > 0 && itemID != "" {
+		SetItemBytesTotal(itemID, expectedSize)
+	}
+
+	out, err := openOutputForWrite(outputPath, outputFD)
+	if err != nil {
+		return err
+	}
+
+	bufWriter := bufio.NewWriterSize(out, 256*1024)
+	var written int64
+	if itemID != "" {
+		pw := NewItemProgressWriter(bufWriter, itemID)
+		written, err = io.Copy(pw, resp.Body)
+	} else {
+		written, err = io.Copy(bufWriter, resp.Body)
+	}
+
+	flushErr := bufWriter.Flush()
+	closeErr := out.Close()
+
+	if err != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
+		return fmt.Errorf("download interrupted: %w", err)
+	}
+	if flushErr != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("failed to flush output: %w", flushErr)
+	}
+	if closeErr != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("failed to close output: %w", closeErr)
+	}
+
+	if expectedSize > 0 && written != expectedSize {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
+	}
+
+	GoLog("[Deezer] Downloaded via Yoinkify: %.2f MB\n", float64(written)/(1024*1024))
+	return nil
+}
+
+func resolveDeezerTrackURL(req DownloadRequest) (string, error) {
+	deezerID := strings.TrimSpace(req.DeezerID)
+	if deezerID == "" {
+		if prefixed, found := strings.CutPrefix(strings.TrimSpace(req.SpotifyID), "deezer:"); found {
+			deezerID = strings.TrimSpace(prefixed)
+		}
+	}
+	if deezerID != "" {
+		trackURL := fmt.Sprintf("https://www.deezer.com/track/%s", deezerID)
+		if err := verifyDeezerTrack(req, deezerID, false); err != nil {
+			GoLog("[Deezer] Direct ID %s verification failed: %v\n", deezerID, err)
+			// Don't reject direct IDs from request payload — they're presumably correct.
+		}
+		return trackURL, nil
+	}
+
+	// Try SongLink
+	spotifyID := strings.TrimSpace(req.SpotifyID)
+	if spotifyID != "" && isLikelySpotifyTrackID(spotifyID) {
+		songlink := NewSongLinkClient()
+		availability, err := songlink.CheckTrackAvailability(spotifyID, "")
+		if err == nil && availability.Deezer && availability.DeezerURL != "" {
+			resolvedID := extractDeezerIDFromURL(availability.DeezerURL)
+			if resolvedID != "" {
+				if verifyErr := verifyDeezerTrack(req, resolvedID, true); verifyErr != nil {
+					GoLog("[Deezer] SongLink ID %s rejected: %v\n", resolvedID, verifyErr)
+					// Fall through to ISRC search instead of using wrong track.
+				} else {
+					return availability.DeezerURL, nil
+				}
+			} else {
+				return availability.DeezerURL, nil
+			}
+		}
+	}
+
+	// Try ISRC
+	isrc := strings.TrimSpace(req.ISRC)
+	if isrc != "" {
+		ctx, cancel := context.WithTimeout(context.Background(), SongLinkTimeout)
+		defer cancel()
+		track, err := GetDeezerClient().SearchByISRC(ctx, isrc)
+		if err == nil && track != nil {
+			resolvedID := songLinkExtractDeezerTrackID(track)
+			if resolvedID != "" {
+				if verifyErr := verifyDeezerTrack(req, resolvedID, false); verifyErr != nil {
+					GoLog("[Deezer] ISRC-resolved ID %s rejected: %v\n", resolvedID, verifyErr)
+					return "", fmt.Errorf("deezer track resolved via ISRC does not match: %w", verifyErr)
+				}
+				return fmt.Sprintf("https://www.deezer.com/track/%s", resolvedID), nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("could not resolve Deezer track URL")
+}
+
+func verifyDeezerTrack(req DownloadRequest, deezerID string, skipNameVerification bool) error {
+	ctx, cancel := context.WithTimeout(context.Background(), SongLinkTimeout)
+	defer cancel()
+	trackResp, err := GetDeezerClient().GetTrack(ctx, deezerID)
+	if err != nil {
+		return nil // Can't verify — don't block the download.
+	}
+	resolved := resolvedTrackInfo{
+		Title:                trackResp.Track.Name,
+		ArtistName:           trackResp.Track.Artists,
+		ISRC:                 trackResp.Track.ISRC,
+		Duration:             trackResp.Track.DurationMS / 1000,
+		SkipNameVerification: skipNameVerification,
+	}
+	if !trackMatchesRequest(req, resolved, "Deezer") {
+		return fmt.Errorf("expected '%s - %s', got '%s - %s'",
+			req.ArtistName, req.TrackName, resolved.ArtistName, resolved.Title)
+	}
+	GoLog("[Deezer] Track %s verified: '%s - %s' ✓\n", deezerID, resolved.ArtistName, resolved.Title)
+	return nil
+}
+
+type deezerMusicDLRequest struct {
+	Platform string `json:"platform"`
+	URL      string `json:"url"`
+}
+
+func (c *DeezerClient) GetMusicDLDownloadURL(deezerTrackURL string) (string, error) {
+	payload := deezerMusicDLRequest{
+		Platform: "deezer",
+		URL:      deezerTrackURL,
+	}
+	jsonData, err := json.Marshal(payload)
+	if err != nil {
+		return "", fmt.Errorf("failed to encode MusicDL request: %w", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, deezerMusicDLURL, bytes.NewReader(jsonData))
+	if err != nil {
+		return "", fmt.Errorf("failed to create MusicDL request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Debug-Key", getQobuzDebugKey())
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("MusicDL request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 64*1024))
+	if err != nil {
+		return "", fmt.Errorf("failed to read MusicDL response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("MusicDL returned HTTP %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+
+	var raw map[string]any
+	if err := json.Unmarshal(body, &raw); err != nil {
+		return "", fmt.Errorf("invalid MusicDL JSON: %w", err)
+	}
+
+	if errMsg, ok := raw["error"].(string); ok && strings.TrimSpace(errMsg) != "" {
+		return "", fmt.Errorf("MusicDL error: %s", errMsg)
+	}
+
+	for _, key := range []string{"download_url", "url", "link"} {
+		if urlVal, ok := raw[key].(string); ok && strings.TrimSpace(urlVal) != "" {
+			return strings.TrimSpace(urlVal), nil
+		}
+	}
+	if data, ok := raw["data"].(map[string]any); ok {
+		for _, key := range []string{"download_url", "url", "link"} {
+			if urlVal, ok := data[key].(string); ok && strings.TrimSpace(urlVal) != "" {
+				return strings.TrimSpace(urlVal), nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("no download URL found in MusicDL response")
+}
+
+func (c *DeezerClient) DownloadFromMusicDL(deezerTrackURL, outputPath string, outputFD int, itemID string) error {
+	GoLog("[Deezer] Resolving download URL via MusicDL for: %s\n", deezerTrackURL)
+
+	downloadURL, err := c.GetMusicDLDownloadURL(deezerTrackURL)
+	if err != nil {
+		return err
+	}
+	GoLog("[Deezer] MusicDL returned download URL, starting download...\n")
+
+	ctx := context.Background()
+	if itemID != "" {
+		StartItemProgress(itemID)
+		defer CompleteItemProgress(itemID)
+		ctx = initDownloadCancel(itemID)
+		defer clearDownloadCancel(itemID)
+	}
+
+	if isDownloadCancelled(itemID) {
+		return ErrDownloadCancelled
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create download request: %w", err)
+	}
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	resp, err := GetDownloadClient().Do(req)
+	if err != nil {
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
+		return fmt.Errorf("download request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("download returned HTTP %d", resp.StatusCode)
+	}
+
+	expectedSize := resp.ContentLength
+	if expectedSize > 0 && itemID != "" {
+		SetItemBytesTotal(itemID, expectedSize)
+	}
+
+	out, err := openOutputForWrite(outputPath, outputFD)
+	if err != nil {
+		return err
+	}
+
+	bufWriter := bufio.NewWriterSize(out, 256*1024)
+	var written int64
+	if itemID != "" {
+		pw := NewItemProgressWriter(bufWriter, itemID)
+		written, err = io.Copy(pw, resp.Body)
+	} else {
+		written, err = io.Copy(bufWriter, resp.Body)
+	}
+
+	flushErr := bufWriter.Flush()
+	closeErr := out.Close()
+
+	if err != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
+		return fmt.Errorf("download interrupted: %w", err)
+	}
+	if flushErr != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("failed to flush output: %w", flushErr)
+	}
+	if closeErr != nil {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("failed to close output: %w", closeErr)
+	}
+
+	if expectedSize > 0 && written != expectedSize {
+		cleanupOutputOnError(outputPath, outputFD)
+		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
+	}
+
+	GoLog("[Deezer] Downloaded via MusicDL: %.2f MB\n", float64(written)/(1024*1024))
+	return nil
+}
+
+func downloadFromDeezer(req DownloadRequest) (DeezerDownloadResult, error) {
+	deezerClient := GetDeezerClient()
+	isSafOutput := isFDOutput(req.OutputFD) || strings.TrimSpace(req.OutputPath) != ""
+
+	if !isSafOutput {
+		if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
+			return DeezerDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
+		}
+	}
+
+	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
+		"title":  req.TrackName,
+		"artist": req.ArtistName,
+		"album":  req.AlbumName,
+		"track":  req.TrackNumber,
+		"year":   extractYear(req.ReleaseDate),
+		"date":   req.ReleaseDate,
+		"disc":   req.DiscNumber,
+	})
+
+	var outputPath string
+	if isSafOutput {
+		outputPath = strings.TrimSpace(req.OutputPath)
+		if outputPath == "" && isFDOutput(req.OutputFD) {
+			outputPath = fmt.Sprintf("/proc/self/fd/%d", req.OutputFD)
+		}
+	} else {
+		filename = sanitizeFilename(filename) + ".flac"
+		outputPath = filepath.Join(req.OutputDir, filename)
+		if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
+			return DeezerDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
+		}
+	}
+
+	var parallelResult *ParallelDownloadResult
+	parallelDone := make(chan struct{})
+	go func() {
+		defer close(parallelDone)
+		coverURL := req.CoverURL
+		embedLyrics := req.EmbedLyrics
+		if !req.EmbedMetadata {
+			coverURL = ""
+			embedLyrics = false
+		}
+		parallelResult = FetchCoverAndLyricsParallel(
+			coverURL,
+			req.EmbedMaxQualityCover,
+			req.SpotifyID,
+			req.TrackName,
+			req.ArtistName,
+			embedLyrics,
+			int64(req.DurationMS),
+		)
+	}()
+
+	// Try MusicDL first (better quality), fallback to Yoinkify
+	var downloadErr error
+	deezerTrackURL, deezerURLErr := resolveDeezerTrackURL(req)
+	if deezerURLErr == nil {
+		GoLog("[Deezer] Trying MusicDL for: %s\n", deezerTrackURL)
+		downloadErr = deezerClient.DownloadFromMusicDL(deezerTrackURL, outputPath, req.OutputFD, req.ItemID)
+		if downloadErr != nil {
+			if errors.Is(downloadErr, ErrDownloadCancelled) {
+				return DeezerDownloadResult{}, ErrDownloadCancelled
+			}
+			GoLog("[Deezer] MusicDL failed: %v, falling back to Yoinkify\n", downloadErr)
+		}
+	} else {
+		GoLog("[Deezer] Could not resolve Deezer URL: %v, using Yoinkify directly\n", deezerURLErr)
+	}
+
+	if downloadErr != nil || deezerURLErr != nil {
+		spotifyURL, err := resolveSpotifyURLForYoinkify(req)
+		if err != nil {
+			if deezerURLErr != nil {
+				return DeezerDownloadResult{}, fmt.Errorf(
+					"deezer download failed: direct Deezer resolution error: %v; Yoinkify fallback error: %w",
+					deezerURLErr,
+					err,
+				)
+			}
+			return DeezerDownloadResult{}, err
+		}
+		downloadErr = deezerClient.DownloadFromYoinkify(spotifyURL, outputPath, req.OutputFD, req.ItemID)
+		if downloadErr != nil {
+			if errors.Is(downloadErr, ErrDownloadCancelled) {
+				return DeezerDownloadResult{}, ErrDownloadCancelled
+			}
+			return DeezerDownloadResult{}, fmt.Errorf("deezer download failed (MusicDL + Yoinkify): %w", downloadErr)
+		}
+	}
+
+	<-parallelDone
+
+	if req.ItemID != "" {
+		SetItemProgress(req.ItemID, 1.0, 0, 0)
+		SetItemFinalizing(req.ItemID)
+	}
+
+	metadata := Metadata{
+		Title:         req.TrackName,
+		Artist:        req.ArtistName,
+		Album:         req.AlbumName,
+		AlbumArtist:   req.AlbumArtist,
+		ArtistTagMode: req.ArtistTagMode,
+		Date:          req.ReleaseDate,
+		TrackNumber:   req.TrackNumber,
+		TotalTracks:   req.TotalTracks,
+		DiscNumber:    req.DiscNumber,
+		ISRC:          req.ISRC,
+		Genre:         req.Genre,
+		Label:         req.Label,
+		Copyright:     req.Copyright,
+	}
+
+	var coverData []byte
+	if parallelResult != nil && parallelResult.CoverData != nil {
+		coverData = parallelResult.CoverData
+	}
+
+	if isSafOutput || !req.EmbedMetadata {
+		if !req.EmbedMetadata {
+			GoLog("[Deezer] Metadata embedding disabled by settings, skipping in-backend metadata/lyrics embedding\n")
+		} else {
+			GoLog("[Deezer] SAF output detected - skipping in-backend metadata/lyrics embedding (handled in Flutter)\n")
+		}
+	} else {
+		if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
+			GoLog("[Deezer] Warning: failed to embed metadata: %v\n", err)
+		}
+
+		if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+			lyricsMode := req.LyricsMode
+			if lyricsMode == "" {
+				lyricsMode = "embed"
+			}
+
+			if lyricsMode == "external" || lyricsMode == "both" {
+				if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
+					GoLog("[Deezer] Warning: failed to save LRC file: %v\n", lrcErr)
+				} else {
+					GoLog("[Deezer] LRC file saved: %s\n", lrcPath)
+				}
+			}
+
+			if lyricsMode == "embed" || lyricsMode == "both" {
+				if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+					GoLog("[Deezer] Warning: failed to embed lyrics: %v\n", embedErr)
+				}
+			}
+		}
+	}
+
+	if !isSafOutput {
+		AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
+	}
+
+	bitDepth, sampleRate := 0, 0
+	if quality, qErr := GetAudioQuality(outputPath); qErr == nil {
+		bitDepth = quality.BitDepth
+		sampleRate = quality.SampleRate
+	}
+
+	lyricsLRC := ""
+	if req.EmbedMetadata && req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+		lyricsLRC = parallelResult.LyricsLRC
+	}
+
+	return DeezerDownloadResult{
+		FilePath:    outputPath,
+		BitDepth:    bitDepth,
+		SampleRate:  sampleRate,
+		Title:       req.TrackName,
+		Artist:      req.ArtistName,
+		Album:       req.AlbumName,
+		ReleaseDate: req.ReleaseDate,
+		TrackNumber: req.TrackNumber,
+		DiscNumber:  req.DiscNumber,
+		ISRC:        req.ISRC,
+		LyricsLRC:   lyricsLRC,
+	}, nil
+}

go_backend/deezer_supplement_test.go

@@ -1,153 +0,0 @@
-package gobackend
-
-import (
-	"context"
-	"io"
-	"net/http"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestDeezerClientWithFakeHTTP(t *testing.T) {
-	client := &DeezerClient{
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			body := fakeDeezerResponse(req.URL.Path, req.URL.RawQuery)
-			status := http.StatusOK
-			if body == "" {
-				status = http.StatusNotFound
-				body = `{"error":"missing"}`
-			}
-			return &http.Response{
-				StatusCode: status,
-				Header:     make(http.Header),
-				Body:       io.NopCloser(strings.NewReader(body)),
-				Request:    req,
-			}, nil
-		})},
-		searchCache:          map[string]*cacheEntry{},
-		albumCache:           map[string]*cacheEntry{},
-		artistCache:          map[string]*cacheEntry{},
-		isrcCache:            map[string]string{},
-		cacheCleanupInterval: time.Millisecond,
-	}
-	ctx := context.Background()
-
-	search, err := client.SearchAll(ctx, "artist song", 2, 2, "")
-	if err != nil {
-		t.Fatalf("SearchAll: %v", err)
-	}
-	if len(search.Tracks) != 1 || len(search.Artists) != 1 || len(search.Albums) != 1 || len(search.Playlists) != 1 {
-		t.Fatalf("search = %#v", search)
-	}
-	cached, err := client.SearchAll(ctx, "artist song", 2, 2, "")
-	if err != nil || cached != search {
-		t.Fatalf("cached SearchAll = %#v/%v", cached, err)
-	}
-	if filtered, err := client.SearchAll(ctx, "artist song", 1, 1, "track"); err != nil || len(filtered.Tracks) != 1 || len(filtered.Artists) != 0 {
-		t.Fatalf("filtered search = %#v/%v", filtered, err)
-	}
-
-	track, err := client.GetTrack(ctx, "101")
-	if err != nil {
-		t.Fatalf("GetTrack: %v", err)
-	}
-	if track.Track.SpotifyID != "deezer:101" || track.Track.Artists != "Contributor A, Contributor B" {
-		t.Fatalf("track = %#v", track)
-	}
-
-	album, err := client.GetAlbum(ctx, "201")
-	if err != nil {
-		t.Fatalf("GetAlbum: %v", err)
-	}
-	if album.AlbumInfo.Name != "Album" || len(album.TrackList) != 2 || album.TrackList[1].ISRC == "" {
-		t.Fatalf("album = %#v", album)
-	}
-	if cachedAlbum, err := client.GetAlbum(ctx, "201"); err != nil || cachedAlbum != album {
-		t.Fatalf("cached album = %#v/%v", cachedAlbum, err)
-	}
-
-	artist, err := client.GetArtist(ctx, "301")
-	if err != nil {
-		t.Fatalf("GetArtist: %v", err)
-	}
-	if artist.ArtistInfo.Name != "Artist" || len(artist.Albums) != 1 || artist.Albums[0].TotalTracks == 0 {
-		t.Fatalf("artist = %#v", artist)
-	}
-	if cachedArtist, err := client.GetArtist(ctx, "301"); err != nil || cachedArtist != artist {
-		t.Fatalf("cached artist = %#v/%v", cachedArtist, err)
-	}
-
-	related, err := client.GetRelatedArtists(ctx, "deezer:301", 3)
-	if err != nil {
-		t.Fatalf("GetRelatedArtists: %v", err)
-	}
-	if len(related) != 1 || related[0].ID != "deezer:302" {
-		t.Fatalf("related = %#v", related)
-	}
-	if _, err := client.GetRelatedArtists(ctx, "", 0); err == nil {
-		t.Fatal("expected invalid related artist ID")
-	}
-
-	playlist, err := client.GetPlaylist(ctx, "401")
-	if err != nil {
-		t.Fatalf("GetPlaylist: %v", err)
-	}
-	if playlist.PlaylistInfo.Tracks.Total != 2 || len(playlist.TrackList) != 2 {
-		t.Fatalf("playlist = %#v", playlist)
-	}
-
-	byISRC, err := client.SearchByISRC(ctx, "USRC17607839")
-	if err != nil {
-		t.Fatalf("SearchByISRC: %v", err)
-	}
-	if byISRC.SpotifyID != "deezer:101" {
-		t.Fatalf("by ISRC = %#v", byISRC)
-	}
-	if _, err := client.SearchByISRC(ctx, "MISSING"); err == nil {
-		t.Fatal("expected missing ISRC error")
-	}
-
-	isrc, err := client.GetTrackISRC(ctx, "102")
-	if err != nil || isrc != "USRC17607840" {
-		t.Fatalf("GetTrackISRC = %q/%v", isrc, err)
-	}
-	albumID, err := client.GetTrackAlbumID(ctx, "101")
-	if err != nil || albumID != "201" {
-		t.Fatalf("GetTrackAlbumID = %q/%v", albumID, err)
-	}
-	extended, err := client.GetAlbumExtendedMetadata(ctx, "201")
-	if err != nil {
-		t.Fatalf("GetAlbumExtendedMetadata: %v", err)
-	}
-	if extended.Genre != "Pop, Dance" || extended.Label != "Label" {
-		t.Fatalf("extended = %#v", extended)
-	}
-	if byTrack, err := client.GetExtendedMetadataByTrackID(ctx, "101"); err != nil || byTrack.Label != "Label" {
-		t.Fatalf("metadata by track = %#v/%v", byTrack, err)
-	}
-	if byISRCMeta, err := client.GetExtendedMetadataByISRC(ctx, "USRC17607839"); err != nil || byISRCMeta.Label != "Label" {
-		t.Fatalf("metadata by isrc = %#v/%v", byISRCMeta, err)
-	}
-	if _, err := client.GetExtendedMetadataByISRC(ctx, ""); err == nil {
-		t.Fatal("expected empty ISRC metadata error")
-	}
-
-	if typ, id, err := parseDeezerURL("https://www.deezer.com/us/track/101"); err != nil || typ != "track" || id != "101" {
-		t.Fatalf("parseDeezerURL = %q/%q/%v", typ, id, err)
-	}
-	if _, _, err := parseDeezerURL("https://example.com/track/101"); err == nil {
-		t.Fatal("expected non-Deezer URL error")
-	}
-
-	client.cacheMu.Lock()
-	client.searchCache["expired"] = &cacheEntry{expiresAt: time.Now().Add(-time.Hour)}
-	client.searchCache["keep1"] = &cacheEntry{expiresAt: time.Now().Add(time.Hour)}
-	client.searchCache["keep2"] = &cacheEntry{expiresAt: time.Now().Add(2 * time.Hour)}
-	client.pruneExpiredCacheEntriesLocked(client.searchCache, time.Now())
-	client.trimCacheEntriesLocked(client.searchCache, 1)
-	client.isrcCache["1"] = "A"
-	client.isrcCache["2"] = "B"
-	client.trimStringCacheEntriesLocked(client.isrcCache, 1)
-	client.cacheMu.Unlock()
-}

go_backend/duplicate.go

@@ -25,6 +25,7 @@ var (
 )
 
 func GetISRCIndex(outputDir string) *ISRCIndex {
+	// Fast path: check cache first
 	isrcIndexCacheMu.RLock()
 	idx, exists := isrcIndexCache[outputDir]
 	isrcIndexCacheMu.RUnlock()
@@ -33,11 +34,13 @@ func GetISRCIndex(outputDir string) *ISRCIndex {
 		return idx
 	}
 
+	// Use per-directory mutex to prevent multiple goroutines from building simultaneously
 	buildLock, _ := isrcBuildingMu.LoadOrStore(outputDir, &sync.Mutex{})
 	mu := buildLock.(*sync.Mutex)
 	mu.Lock()
 	defer mu.Unlock()
 
+	// Double-check cache after acquiring lock (another goroutine may have built it)
 	isrcIndexCacheMu.RLock()
 	idx, exists = isrcIndexCache[outputDir]
 	isrcIndexCacheMu.RUnlock()

go_backend/exports_extension_wrappers_supplement_test.go

@@ -1,83 +0,0 @@
-package gobackend
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-func TestExtensionPackageExportWrappers(t *testing.T) {
-	dir := t.TempDir()
-	extensionsDir := filepath.Join(dir, "extensions")
-	dataDir := filepath.Join(dir, "data")
-	if err := InitExtensionSystem(extensionsDir, dataDir); err != nil {
-		t.Fatalf("InitExtensionSystem: %v", err)
-	}
-	CleanupExtensions()
-	defer CleanupExtensions()
-
-	js := `
-registerExtension({
-  initialize: function(settings) { this.settings = settings || {}; },
-  cleanup: function() {},
-  doAction: function() { return { message: "wrapped", setting_updates: { quality: "lossless" } }; },
-  searchTracks: function() { return { tracks: [], total: 0 }; },
-  fetchLyrics: function() { return { syncType: "UNSYNCED", lines: [{ words: "hello" }] }; },
-  getDownloadUrl: function() { return { url: "https://example.test/a.flac" }; }
-});
-`
-	pkgV1 := filepath.Join(dir, "wrapper-ext-v1.spotiflac-ext")
-	pkgV2 := filepath.Join(dir, "wrapper-ext-v2.spotiflac-ext")
-	createTestExtensionPackage(t, pkgV1, "wrapper-ext", "1.0.0", js, nil)
-	createTestExtensionPackage(t, pkgV2, "wrapper-ext", "1.1.0", js, nil)
-
-	loadedJSON, err := LoadExtensionFromPath(pkgV1)
-	if err != nil || !strings.Contains(loadedJSON, "wrapper-ext") {
-		t.Fatalf("LoadExtensionFromPath = %q/%v", loadedJSON, err)
-	}
-	if installedJSON, err := GetInstalledExtensions(); err != nil || !strings.Contains(installedJSON, "wrapper-ext") {
-		t.Fatalf("GetInstalledExtensions = %q/%v", installedJSON, err)
-	}
-	if err := SetExtensionEnabledByID("wrapper-ext", true); err != nil {
-		t.Fatalf("SetExtensionEnabledByID true: %v", err)
-	}
-	if actionJSON, err := InvokeExtensionActionJSON("wrapper-ext", "doAction"); err != nil || !strings.Contains(actionJSON, "wrapped") {
-		t.Fatalf("InvokeExtensionActionJSON = %q/%v", actionJSON, err)
-	}
-	if upgradeJSON, err := CheckExtensionUpgradeFromPath(pkgV2); err != nil || !strings.Contains(upgradeJSON, `"can_upgrade":true`) {
-		t.Fatalf("CheckExtensionUpgradeFromPath = %q/%v", upgradeJSON, err)
-	}
-	if upgradedJSON, err := UpgradeExtensionFromPath(pkgV2); err != nil || !strings.Contains(upgradedJSON, "1.1.0") {
-		t.Fatalf("UpgradeExtensionFromPath = %q/%v", upgradedJSON, err)
-	}
-	if err := SetExtensionEnabledByID("wrapper-ext", false); err != nil {
-		t.Fatalf("SetExtensionEnabledByID false: %v", err)
-	}
-	if err := UnloadExtensionByID("wrapper-ext"); err != nil {
-		t.Fatalf("UnloadExtensionByID: %v", err)
-	}
-
-	dirExt := filepath.Join(extensionsDir, "wrapper-dir-ext")
-	if err := createDirectoryExtension(dirExt, "wrapper-dir-ext", "1.0.0"); err != nil {
-		t.Fatalf("create directory extension: %v", err)
-	}
-	if loadedDirJSON, err := LoadExtensionsFromDir(extensionsDir); err != nil || !strings.Contains(loadedDirJSON, "wrapper-dir-ext") {
-		t.Fatalf("LoadExtensionsFromDir = %q/%v", loadedDirJSON, err)
-	}
-	if err := RemoveExtensionByID("wrapper-dir-ext"); err != nil {
-		t.Fatalf("RemoveExtensionByID: %v", err)
-	}
-}
-
-func createDirectoryExtension(dir, name, version string) error {
-	if err := os.MkdirAll(dir, 0755); err != nil {
-		return err
-	}
-	manifest := fmt.Sprintf(`{"name":%q,"displayName":%q,"version":%q,"description":"Directory wrapper extension","type":["metadata_provider"],"permissions":{}}`, name, name, version)
-	if err := os.WriteFile(filepath.Join(dir, "manifest.json"), []byte(manifest), 0600); err != nil {
-		return err
-	}
-	return os.WriteFile(filepath.Join(dir, "index.js"), []byte(`registerExtension({searchTracks:function(){return {tracks:[], total:0};}});`), 0600)
-}

go_backend/exports_songlink_lyrics_supplement_test.go

@@ -1,158 +0,0 @@
-package gobackend
-
-import (
-	"context"
-	"io"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestLyricsExportWrappersWithoutNetwork(t *testing.T) {
-	dir := t.TempDir()
-	audioPath := filepath.Join(dir, "sidecar.mp3")
-	if err := os.WriteFile(audioPath, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(dir, "sidecar.lrc"), []byte("[00:00.00]Sidecar lyric"), 0600); err != nil {
-		t.Fatal(err)
-	}
-
-	if jsonText, err := FetchLyrics("spotify-1", "Song Instrumental", "Artist", 180000); err != nil || !strings.Contains(jsonText, `"instrumental":true`) {
-		t.Fatalf("FetchLyrics instrumental = %q/%v", jsonText, err)
-	}
-	if lrc, err := GetLyricsLRC("spotify-1", "Song Instrumental", "Artist", "", 180000); err != nil || lrc != "[instrumental:true]" {
-		t.Fatalf("GetLyricsLRC instrumental = %q/%v", lrc, err)
-	}
-	if jsonText, err := GetLyricsLRCWithSource("spotify-1", "Song Instrumental", "Artist", "", 180000); err != nil || !strings.Contains(jsonText, `"instrumental":true`) {
-		t.Fatalf("GetLyricsLRCWithSource instrumental = %q/%v", jsonText, err)
-	}
-	if lrc, err := GetLyricsLRC("", "", "", audioPath, 0); err != nil || !strings.Contains(lrc, "Sidecar lyric") {
-		t.Fatalf("GetLyricsLRC sidecar = %q/%v", lrc, err)
-	}
-	if jsonText, err := GetLyricsLRCWithSource("", "", "", audioPath, 0); err != nil || !strings.Contains(jsonText, "Sidecar lyric") {
-		t.Fatalf("GetLyricsLRCWithSource sidecar = %q/%v", jsonText, err)
-	}
-
-	outPath := filepath.Join(dir, "lyrics.lrc")
-	if err := FetchAndSaveLyrics("Song", "Artist", "", 0, outPath, audioPath); err != nil {
-		t.Fatalf("FetchAndSaveLyrics sidecar: %v", err)
-	}
-	if data := string(mustReadFile(t, outPath)); !strings.Contains(data, "Sidecar lyric") {
-		t.Fatalf("saved lyrics = %q", data)
-	}
-	if response, err := EmbedLyricsToFile(filepath.Join(dir, "not-flac.mp3"), "lyrics"); err != nil || !strings.Contains(response, `"success":false`) {
-		t.Fatalf("EmbedLyricsToFile error = %q/%v", response, err)
-	}
-	if response, err := RewriteSplitArtistTagsExport(filepath.Join(dir, "not-flac.mp3"), "A;B", "A"); err != nil || !strings.Contains(response, `"success":false`) {
-		t.Fatalf("RewriteSplitArtistTagsExport error = %q/%v", response, err)
-	}
-}
-
-func TestSongLinkExportWrappersWithFakeClient(t *testing.T) {
-	origClient := globalSongLinkClient
-	origRetryConfig := songLinkRetryConfig
-	origSearchByISRC := songLinkSearchByISRC
-	origCheckFromDeezer := songLinkCheckAvailabilityFromDeezer
-	defer func() {
-		globalSongLinkClient = origClient
-		songLinkRetryConfig = origRetryConfig
-		songLinkSearchByISRC = origSearchByISRC
-		songLinkCheckAvailabilityFromDeezer = origCheckFromDeezer
-		SetSongLinkNetworkOptions(false, false)
-	}()
-	songLinkRetryConfig = func() RetryConfig {
-		return RetryConfig{MaxRetries: 0, InitialDelay: 0, MaxDelay: 0, BackoffFactor: 1}
-	}
-	globalSongLinkClient = &SongLinkClient{client: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		var body string
-		if req.URL.Host == "api.zarz.moe" {
-			body = `{"success":true,"songUrls":{"Spotify":"https://open.spotify.com/track/spotify-1","Deezer":"https://www.deezer.com/track/101","Tidal":"https://listen.tidal.com/track/202","YouTube":"https://youtu.be/yt1","AmazonMusic":"https://music.amazon.com/tracks/amz1","Qobuz":"https://open.qobuz.com/track/303"}}`
-		} else if req.URL.Host == "api.song.link" {
-			body = `{"linksByPlatform":{"spotify":{"url":"https://open.spotify.com/track/spotify-1"},"deezer":{"url":"https://www.deezer.com/track/101"},"tidal":{"url":"https://listen.tidal.com/track/202"},"youtubeMusic":{"url":"https://music.youtube.com/watch?v=ytm1"},"amazonMusic":{"url":"https://music.amazon.com/tracks/amz1"},"qobuz":{"url":"https://open.qobuz.com/track/303"}}}`
-		} else {
-			t.Fatalf("unexpected SongLink request: %s", req.URL.String())
-		}
-		return &http.Response{StatusCode: http.StatusOK, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(body)), Request: req}, nil
-	})}}
-	songLinkClientOnce.Do(func() {})
-
-	SetSongLinkNetworkOptions(true, true)
-	if availabilityJSON, err := CheckAvailability("spotify-1", ""); err != nil || !strings.Contains(availabilityJSON, `"deezer_id":"101"`) {
-		t.Fatalf("CheckAvailability = %q/%v", availabilityJSON, err)
-	}
-	if availabilityJSON, err := CheckAvailabilityFromDeezerID("101"); err != nil || !strings.Contains(availabilityJSON, `"spotify_id":"spotify-1"`) {
-		t.Fatalf("CheckAvailabilityFromDeezerID = %q/%v", availabilityJSON, err)
-	}
-	if availabilityJSON, err := CheckAvailabilityByPlatformID("deezer", "song", "101"); err != nil || !strings.Contains(availabilityJSON, `"tidal_url"`) {
-		t.Fatalf("CheckAvailabilityByPlatformID = %q/%v", availabilityJSON, err)
-	}
-	if spotifyID, err := GetSpotifyIDFromDeezerTrack("101"); err != nil || spotifyID != "spotify-1" {
-		t.Fatalf("GetSpotifyIDFromDeezerTrack = %q/%v", spotifyID, err)
-	}
-	if tidalURL, err := GetTidalURLFromDeezerTrack("101"); err != nil || !strings.Contains(tidalURL, "tidal") {
-		t.Fatalf("GetTidalURLFromDeezerTrack = %q/%v", tidalURL, err)
-	}
-	if urls, err := NewSongLinkClient().GetStreamingURLs("spotify-1"); err != nil || urls["tidal"] == "" || urls["amazon"] == "" {
-		t.Fatalf("GetStreamingURLs = %#v/%v", urls, err)
-	}
-	if youtubeURL, err := NewSongLinkClient().GetYouTubeURLFromSpotify("spotify-1"); err != nil || !strings.Contains(youtubeURL, "youtu") {
-		t.Fatalf("GetYouTubeURLFromSpotify = %q/%v", youtubeURL, err)
-	}
-	if amazonURL, err := NewSongLinkClient().GetAmazonURLFromDeezer("101"); err != nil || !strings.Contains(amazonURL, "amazon") {
-		t.Fatalf("GetAmazonURLFromDeezer = %q/%v", amazonURL, err)
-	}
-	if youtubeURL, err := NewSongLinkClient().GetYouTubeURLFromDeezer("101"); err != nil || !strings.Contains(youtubeURL, "youtube") {
-		t.Fatalf("GetYouTubeURLFromDeezer = %q/%v", youtubeURL, err)
-	}
-	if deezerID, err := NewSongLinkClient().GetDeezerIDFromSpotify("spotify-1"); err != nil || deezerID != "101" {
-		t.Fatalf("GetDeezerIDFromSpotify = %q/%v", deezerID, err)
-	}
-	if album, err := NewSongLinkClient().CheckAlbumAvailability("album-1"); err != nil || !album.Deezer || album.DeezerID == "" {
-		t.Fatalf("CheckAlbumAvailability = %#v/%v", album, err)
-	}
-	if albumID, err := NewSongLinkClient().GetDeezerAlbumIDFromSpotify("album-1"); err != nil || albumID == "" {
-		t.Fatalf("GetDeezerAlbumIDFromSpotify = %q/%v", albumID, err)
-	}
-	if availability, err := NewSongLinkClient().CheckAvailabilityFromURL("https://www.deezer.com/track/101"); err != nil || !availability.Deezer {
-		t.Fatalf("CheckAvailabilityFromURL = %#v/%v", availability, err)
-	}
-
-	songLinkSearchByISRC = func(ctx context.Context, isrc string) (*TrackMetadata, error) {
-		return &TrackMetadata{SpotifyID: "deezer:101", ExternalURL: "https://www.deezer.com/track/101"}, nil
-	}
-	songLinkCheckAvailabilityFromDeezer = func(s *SongLinkClient, deezerTrackID string) (*TrackAvailability, error) {
-		return &TrackAvailability{SpotifyID: "spotify-1", Deezer: true, DeezerID: deezerTrackID}, nil
-	}
-	if availabilityJSON, err := CheckAvailability("", "USRC17607839"); err != nil || !strings.Contains(availabilityJSON, `"deezer_id":"101"`) {
-		t.Fatalf("CheckAvailability by ISRC = %q/%v", availabilityJSON, err)
-	}
-	if songLinkExtractDeezerTrackID(nil) != "" || songLinkExtractDeezerTrackID(&TrackMetadata{ExternalURL: "https://www.deezer.com/track/202"}) != "202" {
-		t.Fatal("songLinkExtractDeezerTrackID mismatch")
-	}
-
-	deezerClient = &DeezerClient{
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			body := fakeDeezerResponse(req.URL.Path, req.URL.RawQuery)
-			if body == "" {
-				body = `{"error":"missing"}`
-			}
-			return &http.Response{StatusCode: http.StatusOK, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(body)), Request: req}, nil
-		})},
-		searchCache:          map[string]*cacheEntry{},
-		albumCache:           map[string]*cacheEntry{},
-		artistCache:          map[string]*cacheEntry{},
-		isrcCache:            map[string]string{},
-		cacheCleanupInterval: time.Hour,
-	}
-	deezerClientOnce.Do(func() {})
-	if jsonText, err := ConvertSpotifyToDeezer("track", "spotify-1"); err != nil || !strings.Contains(jsonText, `"spotify_id":"deezer:101"`) {
-		t.Fatalf("ConvertSpotifyToDeezer track = %q/%v", jsonText, err)
-	}
-	if jsonText, err := ConvertSpotifyToDeezer("album", "album-1"); err != nil || jsonText == "" {
-		t.Fatalf("ConvertSpotifyToDeezer album = %q/%v", jsonText, err)
-	}
-}

go_backend/exports_supplement_test.go

@@ -1,412 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"io"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestExportsJSONWrappersAndExtensionManagerSurface(t *testing.T) {
-	dir := t.TempDir()
-	dataDir := filepath.Join(dir, "data")
-	extensionsDir := filepath.Join(dir, "extensions")
-	if err := InitExtensionSystem(extensionsDir, dataDir); err != nil {
-		t.Fatalf("InitExtensionSystem: %v", err)
-	}
-
-	ext := newTestLoadedExtension(t, ExtensionTypeMetadataProvider, ExtensionTypeDownloadProvider, ExtensionTypeLyricsProvider)
-	manager := getExtensionManager()
-	manager.mu.Lock()
-	if manager.extensions == nil {
-		manager.extensions = map[string]*loadedExtension{}
-	}
-	manager.extensions[ext.ID] = ext
-	manager.mu.Unlock()
-	defer func() {
-		manager.mu.Lock()
-		delete(manager.extensions, ext.ID)
-		manager.mu.Unlock()
-	}()
-
-	if response, err := DownloadTrack(`{}`); err != nil || !strings.Contains(response, "retired") {
-		t.Fatalf("DownloadTrack = %q/%v", response, err)
-	}
-	if response, err := DownloadByStrategy(`not-json`); err != nil || !strings.Contains(response, "Invalid request") {
-		t.Fatalf("DownloadByStrategy invalid = %q/%v", response, err)
-	}
-	if response, err := DownloadByStrategy(`{"use_extensions":false}`); err != nil || !strings.Contains(response, "disabled") {
-		t.Fatalf("DownloadByStrategy disabled = %q/%v", response, err)
-	}
-	if response, err := DownloadWithFallback(`{}`); err != nil || !strings.Contains(response, "retired") {
-		t.Fatalf("DownloadWithFallback = %q/%v", response, err)
-	}
-
-	InitItemProgress("item-1")
-	FinishItemProgress("item-1")
-	ClearItemProgress("item-1")
-	CancelDownload("item-1")
-	if GetDownloadProgress() == "" || GetAllDownloadProgress() == "" || GetAllDownloadProgressDelta(0) == "" {
-		t.Fatal("expected progress JSON")
-	}
-	CleanupConnections()
-
-	cuePath, audioPath := writeExportCueFixture(t, dir)
-	if jsonText, err := ParseCueSheet(cuePath, ""); err != nil {
-		t.Fatalf("ParseCueSheet = %q/%v", jsonText, err)
-	} else {
-		var parsed CueSplitInfo
-		if err := json.Unmarshal([]byte(jsonText), &parsed); err != nil {
-			t.Fatalf("decode ParseCueSheet: %v", err)
-		}
-		if parsed.AudioPath != audioPath {
-			t.Fatalf("ParseCueSheet audio path = %q want %q", parsed.AudioPath, audioPath)
-		}
-	}
-	if jsonText, err := ScanCueSheetForLibrary(cuePath, "", "virtual.cue", 111); err != nil || !strings.Contains(jsonText, "cue+wav") {
-		t.Fatalf("ScanCueSheetForLibrary = %q/%v", jsonText, err)
-	}
-	if jsonText, err := ScanCueSheetForLibraryWithCoverCacheKey(cuePath, "", "virtual.cue", 111, "cover-key"); err != nil || !strings.Contains(jsonText, "cue+wav") {
-		t.Fatalf("ScanCueSheetForLibraryWithCoverCacheKey = %q/%v", jsonText, err)
-	}
-
-	apePath := filepath.Join(dir, "edit.ape")
-	if err := os.WriteFile(apePath, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	editJSON := `{"title":"Edited","artist":"Artist","track_number":"1","track_total":"2","disc_number":"1","disc_total":"1"}`
-	if response, err := EditFileMetadata(apePath, editJSON); err != nil || !strings.Contains(response, "native_ape") {
-		t.Fatalf("EditFileMetadata ape = %q/%v", response, err)
-	}
-	if response, err := EditFileMetadata(filepath.Join(dir, "edit.mp3"), editJSON); err != nil || !strings.Contains(response, "ffmpeg") {
-		t.Fatalf("EditFileMetadata ffmpeg = %q/%v", response, err)
-	}
-	if _, err := EditFileMetadata(apePath, `not-json`); err == nil {
-		t.Fatal("expected invalid metadata JSON")
-	}
-	if !hasOnlyM4AReplayGainFields(map[string]string{"replaygain_track_gain": "-1 dB"}) {
-		t.Fatal("expected replaygain-only fields")
-	}
-	if hasOnlyM4AReplayGainFields(map[string]string{"title": "Song"}) {
-		t.Fatal("expected non-replaygain field rejection")
-	}
-
-	AllowDownloadDir(dir)
-	if err := SetDownloadDirectory(dir); err != nil {
-		t.Fatalf("SetDownloadDirectory: %v", err)
-	}
-	if duplicateJSON, err := CheckDuplicate(dir, ""); err != nil || !strings.Contains(duplicateJSON, "exists") {
-		t.Fatalf("CheckDuplicate = %q/%v", duplicateJSON, err)
-	}
-	if batchJSON, err := CheckDuplicatesBatch(dir, `[{"isrc":"","track_name":"Song","artist_name":"Artist"}]`); err != nil || !strings.Contains(batchJSON, "Song") {
-		t.Fatalf("CheckDuplicatesBatch = %q/%v", batchJSON, err)
-	}
-	_ = PreBuildDuplicateIndex(dir)
-	InvalidateDuplicateIndex(dir)
-	if filename, err := BuildFilename("{artist} - {title}", `{"artist":"A/B","title":"Song?"}`); err != nil || filename == "" {
-		t.Fatalf("BuildFilename = %q/%v", filename, err)
-	}
-	if _, err := BuildFilename("{title}", `not-json`); err == nil {
-		t.Fatal("expected BuildFilename JSON error")
-	}
-	if got := SanitizeFilename(`A/B:C*D?`); strings.ContainsAny(got, `/:*?`) {
-		t.Fatalf("SanitizeFilename = %q", got)
-	}
-
-	if response, err := PreWarmTrackCacheJSON(`not-json`); err != nil || !strings.Contains(response, "Invalid JSON") {
-		t.Fatalf("PreWarmTrackCacheJSON invalid = %q/%v", response, err)
-	}
-	if response, err := PreWarmTrackCacheJSON(`[{"isrc":"ISRC","track_name":"Song","artist_name":"Artist"}]`); err != nil || !strings.Contains(response, "success") {
-		t.Fatalf("PreWarmTrackCacheJSON = %q/%v", response, err)
-	}
-	if GetTrackCacheSize() != 0 {
-		t.Fatal("expected empty track cache")
-	}
-	ClearTrackIDCache()
-
-	if err := SetLyricsProvidersJSON(`["lrclib","apple_music"]`); err != nil {
-		t.Fatalf("SetLyricsProvidersJSON: %v", err)
-	}
-	if providers, err := GetLyricsProvidersJSON(); err != nil || !strings.Contains(providers, "lrclib") {
-		t.Fatalf("GetLyricsProvidersJSON = %q/%v", providers, err)
-	}
-	if available, err := GetAvailableLyricsProvidersJSON(); err != nil || available == "" {
-		t.Fatalf("GetAvailableLyricsProvidersJSON = %q/%v", available, err)
-	}
-	if err := SetLyricsFetchOptionsJSON(`{"include_translation_netease":true}`); err != nil {
-		t.Fatalf("SetLyricsFetchOptionsJSON: %v", err)
-	}
-	if opts, err := GetLyricsFetchOptionsJSON(); err != nil || opts == "" {
-		t.Fatalf("GetLyricsFetchOptionsJSON = %q/%v", opts, err)
-	}
-
-	if err := SetProviderPriorityJSON(`["coverage-ext"]`); err != nil {
-		t.Fatalf("SetProviderPriorityJSON: %v", err)
-	}
-	if jsonText, err := GetProviderPriorityJSON(); err != nil || !strings.Contains(jsonText, "coverage-ext") {
-		t.Fatalf("GetProviderPriorityJSON = %q/%v", jsonText, err)
-	}
-	if err := SetExtensionFallbackProviderIDsJSON(`["coverage-ext"]`); err != nil {
-		t.Fatalf("SetExtensionFallbackProviderIDsJSON: %v", err)
-	}
-	if jsonText, err := GetExtensionFallbackProviderIDsJSON(); err != nil || !strings.Contains(jsonText, "coverage-ext") {
-		t.Fatalf("GetExtensionFallbackProviderIDsJSON = %q/%v", jsonText, err)
-	}
-	if err := SetExtensionFallbackProviderIDsJSON(""); err != nil {
-		t.Fatalf("reset extension fallback IDs: %v", err)
-	}
-	if err := SetMetadataProviderPriorityJSON(`["coverage-ext"]`); err != nil {
-		t.Fatalf("SetMetadataProviderPriorityJSON: %v", err)
-	}
-	if jsonText, err := GetMetadataProviderPriorityJSON(); err != nil || !strings.Contains(jsonText, "coverage-ext") {
-		t.Fatalf("GetMetadataProviderPriorityJSON = %q/%v", jsonText, err)
-	}
-
-	if err := SetExtensionSettingsJSON(ext.ID, `{"quality":"lossless","_secret":"hidden"}`); err != nil {
-		t.Fatalf("SetExtensionSettingsJSON: %v", err)
-	}
-	if settingsJSON, err := GetExtensionSettingsJSON(ext.ID); err != nil || !strings.Contains(settingsJSON, "quality") {
-		t.Fatalf("GetExtensionSettingsJSON = %q/%v", settingsJSON, err)
-	}
-	if err := SetExtensionSettingsJSON(ext.ID, `not-json`); err == nil {
-		t.Fatal("expected settings JSON error")
-	}
-
-	if jsonText, err := SearchTracksWithExtensionsJSON("song", 5); err != nil || !strings.Contains(jsonText, "search-1") {
-		t.Fatalf("SearchTracksWithExtensionsJSON = %q/%v", jsonText, err)
-	}
-	if jsonText, err := SearchTracksWithMetadataProvidersJSON("song", 5, true); err != nil || !strings.Contains(jsonText, "search-1") {
-		t.Fatalf("SearchTracksWithMetadataProvidersJSON = %q/%v", jsonText, err)
-	}
-	if jsonText, err := GetProviderMetadataJSON(ext.ID, "track", "track-1"); err != nil || !strings.Contains(jsonText, "Track track-1") {
-		t.Fatalf("GetProviderMetadataJSON track = %q/%v", jsonText, err)
-	}
-	for _, resourceType := range []string{"album", "playlist", "artist"} {
-		if jsonText, err := GetProviderMetadataJSON(ext.ID, resourceType, resourceType+"-1"); err != nil || jsonText == "" {
-			t.Fatalf("GetProviderMetadataJSON %s = %q/%v", resourceType, jsonText, err)
-		}
-	}
-	if _, err := GetProviderMetadataJSON("", "track", "id"); err == nil {
-		t.Fatal("expected empty provider ID error")
-	}
-	if _, err := GetProviderMetadataJSON(ext.ID, "unsupported", "id"); err == nil {
-		t.Fatal("expected unsupported provider type")
-	}
-	if firstNonEmptyTrimmed(" ", " value ") != "value" {
-		t.Fatal("expected first trimmed value")
-	}
-	requestJSON := `{"use_extensions":true,"use_fallback":false,"service":"coverage-ext","source":"coverage-ext","track_name":"Song","artist_name":"Artist","album_name":"Album","output_dir":"` + escapeJSONPath(dir) + `","output_ext":".flac","quality":"LOSSLESS"}`
-	if jsonText, err := DownloadWithExtensionsJSON(requestJSON); err != nil || !strings.Contains(jsonText, "coverage-ext") {
-		t.Fatalf("DownloadWithExtensionsJSON = %q/%v", jsonText, err)
-	}
-	if _, err := DownloadWithExtensionsJSON(`not-json`); err == nil {
-		t.Fatal("expected DownloadWithExtensionsJSON JSON error")
-	}
-
-	SetExtensionAuthCodeByID(ext.ID, "code")
-	SetExtensionTokensByID(ext.ID, "access", "refresh", 60)
-	if !IsExtensionAuthenticatedByID(ext.ID) {
-		t.Fatal("expected authenticated extension")
-	}
-	if pending, err := GetExtensionPendingAuthJSON(ext.ID); err != nil || pending != "" {
-		t.Fatalf("GetExtensionPendingAuthJSON = %q/%v", pending, err)
-	}
-	ClearExtensionPendingAuthByID(ext.ID)
-	if all, err := GetAllPendingAuthRequestsJSON(); err != nil || all == "" {
-		t.Fatalf("GetAllPendingAuthRequestsJSON = %q/%v", all, err)
-	}
-
-	ffmpegCommandsMu.Lock()
-	ffmpegCommands["cmd-1"] = &FFmpegCommand{ExtensionID: ext.ID, Command: "ffmpeg -version", InputPath: "in", OutputPath: "out"}
-	ffmpegCommandsMu.Unlock()
-	if cmdJSON, err := GetPendingFFmpegCommandJSON("cmd-1"); err != nil || !strings.Contains(cmdJSON, "cmd-1") {
-		t.Fatalf("GetPendingFFmpegCommandJSON = %q/%v", cmdJSON, err)
-	}
-	if all, err := GetAllPendingFFmpegCommandsJSON(); err != nil || !strings.Contains(all, "cmd-1") {
-		t.Fatalf("GetAllPendingFFmpegCommandsJSON = %q/%v", all, err)
-	}
-	SetFFmpegCommandResultByID("cmd-1", true, "ok", "")
-	ClearFFmpegCommand("cmd-1")
-	if empty, err := GetPendingFFmpegCommandJSON("missing"); err != nil || empty != "" {
-		t.Fatalf("missing ffmpeg = %q/%v", empty, err)
-	}
-
-	enrichedJSON, err := EnrichTrackWithExtensionJSON(ext.ID, `{"id":"track-1","name":"Old","artists":"Artist"}`)
-	if err != nil || !strings.Contains(enrichedJSON, "Enriched") {
-		t.Fatalf("EnrichTrackWithExtensionJSON = %q/%v", enrichedJSON, err)
-	}
-	if sameJSON, err := EnrichTrackWithExtensionJSON("missing", `{"name":"Old"}`); err != nil || !strings.Contains(sameJSON, "Old") {
-		t.Fatalf("missing EnrichTrackWithExtensionJSON = %q/%v", sameJSON, err)
-	}
-
-	deezerClient = &DeezerClient{
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			body := fakeDeezerResponse(req.URL.Path, req.URL.RawQuery)
-			status := http.StatusOK
-			if body == "" {
-				status = http.StatusNotFound
-				body = `{"error":"missing"}`
-			}
-			return &http.Response{StatusCode: status, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(body)), Request: req}, nil
-		})},
-		searchCache:          map[string]*cacheEntry{},
-		albumCache:           map[string]*cacheEntry{},
-		artistCache:          map[string]*cacheEntry{},
-		isrcCache:            map[string]string{},
-		cacheCleanupInterval: time.Hour,
-	}
-	deezerClientOnce.Do(func() {})
-	for _, item := range []struct {
-		typ string
-		id  string
-	}{
-		{"track", "101"},
-		{"album", "201"},
-		{"artist", "301"},
-		{"playlist", "401"},
-	} {
-		if jsonText, err := GetDeezerMetadata(item.typ, item.id); err != nil || jsonText == "" {
-			t.Fatalf("GetDeezerMetadata %s = %q/%v", item.typ, jsonText, err)
-		}
-	}
-	if _, err := GetDeezerMetadata("bad", "1"); err == nil {
-		t.Fatal("expected unsupported Deezer metadata type")
-	}
-	if jsonText, err := GetDeezerRelatedArtists("301", 2); err != nil || !strings.Contains(jsonText, "Related") {
-		t.Fatalf("GetDeezerRelatedArtists = %q/%v", jsonText, err)
-	}
-	if jsonText, err := GetDeezerExtendedMetadata("101"); err != nil || !strings.Contains(jsonText, "Label") {
-		t.Fatalf("GetDeezerExtendedMetadata = %q/%v", jsonText, err)
-	}
-	if _, err := GetDeezerExtendedMetadata(""); err == nil {
-		t.Fatal("expected empty Deezer metadata ID error")
-	}
-	if jsonText, err := SearchDeezerByISRC("USRC17607839"); err != nil || !strings.Contains(jsonText, "deezer:101") {
-		t.Fatalf("SearchDeezerByISRC = %q/%v", jsonText, err)
-	}
-	if jsonText, err := SearchDeezerByISRCForItemID("USRC17607839", "item-isrc"); err != nil || !strings.Contains(jsonText, "deezer:101") {
-		t.Fatalf("SearchDeezerByISRCForItemID = %q/%v", jsonText, err)
-	}
-
-	customJSON, err := CustomSearchWithExtensionJSON(ext.ID, "needle", `{"filter":"tracks"}`)
-	if err != nil || !strings.Contains(customJSON, "Custom needle") {
-		t.Fatalf("CustomSearchWithExtensionJSON = %q/%v", customJSON, err)
-	}
-	if customJSON, err := CustomSearchWithExtensionJSONWithRequestID(ext.ID, "needle", `not-json`, "req-custom"); err != nil || !strings.Contains(customJSON, "custom-1") {
-		t.Fatalf("CustomSearchWithExtensionJSONWithRequestID = %q/%v", customJSON, err)
-	}
-	if providersJSON, err := GetSearchProvidersJSON(); err != nil || !strings.Contains(providersJSON, "coverage-ext") {
-		t.Fatalf("GetSearchProvidersJSON = %q/%v", providersJSON, err)
-	}
-	if found := FindURLHandlerJSON("https://example.test/track/1"); found != ext.ID {
-		t.Fatalf("FindURLHandlerJSON = %q", found)
-	}
-	if handlersJSON, err := GetURLHandlersJSON(); err != nil || !strings.Contains(handlersJSON, "coverage-ext") {
-		t.Fatalf("GetURLHandlersJSON = %q/%v", handlersJSON, err)
-	}
-	if handledJSON, err := HandleURLWithExtensionJSON("https://example.test/track/1"); err != nil || !strings.Contains(handledJSON, "url-track") {
-		t.Fatalf("HandleURLWithExtensionJSON = %q/%v", handledJSON, err)
-	}
-	if postJSON, err := RunPostProcessingJSON(filepath.Join(dir, "song.flac"), `{"title":"Song"}`); err != nil || !strings.Contains(postJSON, "success") {
-		t.Fatalf("RunPostProcessingJSON = %q/%v", postJSON, err)
-	}
-	v2Input := `{"path":"` + escapeJSONPath(filepath.Join(dir, "song.flac")) + `","uri":"content://song","name":"song.flac","mime_type":"audio/flac","size":10}`
-	if postJSON, err := RunPostProcessingV2JSON(v2Input, `not-json`); err != nil || !strings.Contains(postJSON, "success") {
-		t.Fatalf("RunPostProcessingV2JSON = %q/%v", postJSON, err)
-	}
-	if postProviders, err := GetPostProcessingProvidersJSON(); err != nil || !strings.Contains(postProviders, "hook") {
-		t.Fatalf("GetPostProcessingProvidersJSON = %q/%v", postProviders, err)
-	}
-	if feedJSON, err := GetExtensionHomeFeedJSON(ext.ID); err != nil || !strings.Contains(feedJSON, "home-1") {
-		t.Fatalf("GetExtensionHomeFeedJSON = %q/%v", feedJSON, err)
-	}
-	if feedJSON, err := GetExtensionHomeFeedJSONWithRequestID(ext.ID, "req-home"); err != nil || !strings.Contains(feedJSON, "home-1") {
-		t.Fatalf("GetExtensionHomeFeedJSONWithRequestID = %q/%v", feedJSON, err)
-	}
-	if categoriesJSON, err := GetExtensionBrowseCategoriesJSON(ext.ID); err != nil || !strings.Contains(categoriesJSON, "cat-1") {
-		t.Fatalf("GetExtensionBrowseCategoriesJSON = %q/%v", categoriesJSON, err)
-	}
-	CancelExtensionRequestJSON("req-home")
-
-	storeDir := filepath.Join(dir, "store")
-	if err := InitExtensionStoreJSON(storeDir); err != nil {
-		t.Fatalf("InitExtensionStoreJSON: %v", err)
-	}
-	if err := SetStoreRegistryURLJSON("https://registry.example.com/index.json"); err != nil {
-		t.Fatalf("SetStoreRegistryURLJSON: %v", err)
-	}
-	store := getExtensionStore()
-	store.cache = &storeRegistry{Extensions: []storeExtension{{
-		ID:          "coverage-ext",
-		Name:        "coverage-ext",
-		Version:     "1.0.0",
-		Description: "Coverage",
-		Category:    CategoryMetadata,
-		Tags:        []string{"metadata"},
-		DownloadURL: "https://registry.example.com/coverage.spotiflac-ext",
-	}}}
-	store.cacheTime = time.Now()
-	if registryURL, err := GetStoreRegistryURLJSON(); err != nil || registryURL == "" {
-		t.Fatalf("GetStoreRegistryURLJSON = %q/%v", registryURL, err)
-	}
-	if storeJSON, err := GetStoreExtensionsJSON(false); err != nil || !strings.Contains(storeJSON, "coverage-ext") {
-		t.Fatalf("GetStoreExtensionsJSON = %q/%v", storeJSON, err)
-	}
-	if storeJSON, err := SearchStoreExtensionsJSON("coverage", CategoryMetadata); err != nil || !strings.Contains(storeJSON, "coverage-ext") {
-		t.Fatalf("SearchStoreExtensionsJSON = %q/%v", storeJSON, err)
-	}
-	if catsJSON, err := GetStoreCategoriesJSON(); err != nil || !strings.Contains(catsJSON, "metadata") {
-		t.Fatalf("GetStoreCategoriesJSON = %q/%v", catsJSON, err)
-	}
-	if dest, err := buildStoreExtensionDestPath(dir, "coverage/ext"); err != nil || !strings.HasSuffix(dest, ".spotiflac-ext") {
-		t.Fatalf("buildStoreExtensionDestPath = %q/%v", dest, err)
-	}
-	if _, err := buildStoreExtensionDestPath(dir, " "); err == nil {
-		t.Fatal("expected invalid extension id")
-	}
-	if err := ClearStoreCacheJSON(); err != nil {
-		t.Fatalf("ClearStoreCacheJSON: %v", err)
-	}
-	if err := ClearStoreRegistryURLJSON(); err != nil {
-		t.Fatalf("ClearStoreRegistryURLJSON: %v", err)
-	}
-
-	SetLibraryCoverCacheDirJSON(filepath.Join(dir, "covers"))
-	libraryDir := filepath.Join(dir, "library")
-	if err := os.MkdirAll(libraryDir, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(libraryDir, "Artist - Song.mp3"), []byte("not mp3"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if scanJSON, err := ScanLibraryFolderJSON(libraryDir); err != nil || !strings.Contains(scanJSON, "Song") {
-		t.Fatalf("ScanLibraryFolderJSON = %q/%v", scanJSON, err)
-	}
-	if scanJSON, err := ScanLibraryFolderIncrementalJSON(libraryDir, `[]`); err != nil || !strings.Contains(scanJSON, "Song") {
-		t.Fatalf("ScanLibraryFolderIncrementalJSON = %q/%v", scanJSON, err)
-	}
-	snapshotPath := filepath.Join(dir, "snapshot.json")
-	if err := os.WriteFile(snapshotPath, []byte(`[]`), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if scanJSON, err := ScanLibraryFolderIncrementalFromSnapshotJSON(libraryDir, snapshotPath); err != nil || !strings.Contains(scanJSON, "Song") {
-		t.Fatalf("ScanLibraryFolderIncrementalFromSnapshotJSON = %q/%v", scanJSON, err)
-	}
-	if GetLibraryScanProgressJSON() == "" {
-		t.Fatal("expected scan progress JSON")
-	}
-	CancelLibraryScanJSON()
-	if metadataJSON, err := ReadAudioMetadataJSON(filepath.Join(libraryDir, "missing.mp3")); err != nil || metadataJSON == "" {
-		t.Fatalf("ReadAudioMetadataJSON = %q/%v", metadataJSON, err)
-	}
-	if metadataJSON, err := ReadAudioMetadataWithHintJSON(filepath.Join(libraryDir, "missing.mp3"), "Missing"); err != nil || metadataJSON == "" {
-		t.Fatalf("ReadAudioMetadataWithHintJSON = %q/%v", metadataJSON, err)
-	}
-	if metadataJSON, err := ReadAudioMetadataWithHintAndCoverCacheKeyJSON(filepath.Join(libraryDir, "missing.mp3"), "Missing", "key"); err != nil || metadataJSON == "" {
-		t.Fatalf("ReadAudioMetadataWithHintAndCoverCacheKeyJSON = %q/%v", metadataJSON, err)
-	}
-}

go_backend/exports_test.go

@@ -1,25 +1,6 @@
 package gobackend
 
-import (
-	"context"
-	"fmt"
-	"testing"
-)
-
-func TestSetExtensionFallbackProviderIDsJSONEmptyStringResetsDefault(t *testing.T) {
-	original := GetExtensionFallbackProviderIDs()
-	defer SetExtensionFallbackProviderIDs(original)
-
-	SetExtensionFallbackProviderIDs([]string{"custom-ext"})
-
-	if err := SetExtensionFallbackProviderIDsJSON(""); err != nil {
-		t.Fatalf("SetExtensionFallbackProviderIDsJSON returned error: %v", err)
-	}
-
-	if got := GetExtensionFallbackProviderIDs(); got != nil {
-		t.Fatalf("expected nil fallback provider list after reset, got %v", got)
-	}
-}
+import "testing"
 
 func TestBuildDownloadSuccessResponsePrefersRequestedAlbumMetadata(t *testing.T) {
 	req := DownloadRequest{
@@ -133,216 +114,6 @@ func TestBuildDownloadSuccessResponsePrefersProviderCoverURL(t *testing.T) {
 	}
 }
 
-func TestBuildDownloadSuccessResponseNormalizesDecryptionDescriptor(t *testing.T) {
-	req := DownloadRequest{
-		TrackName:  "Track",
-		ArtistName: "Artist",
-	}
-
-	result := DownloadResult{
-		Title:         "Track",
-		Artist:        "Artist",
-		DecryptionKey: "00112233",
-	}
-
-	resp := buildDownloadSuccessResponse(
-		req,
-		result,
-		"amazon",
-		"ok",
-		"/tmp/test.m4a",
-		false,
-	)
-
-	if resp.Decryption == nil {
-		t.Fatal("expected decryption descriptor to be present")
-	}
-	if resp.Decryption.Strategy != genericFFmpegMOVDecryptionStrategy {
-		t.Fatalf("strategy = %q", resp.Decryption.Strategy)
-	}
-	if resp.Decryption.Key != result.DecryptionKey {
-		t.Fatalf("key = %q, want %q", resp.Decryption.Key, result.DecryptionKey)
-	}
-}
-
-func TestFormatMusicBrainzGenrePrefersHighestCountTag(t *testing.T) {
-	got := formatMusicBrainzGenre([]musicBrainzTag{
-		{Name: "art pop", Count: 3},
-		{Name: "pop", Count: 8},
-		{Name: "dance pop", Count: 5},
-	})
-
-	if got != "Pop" {
-		t.Fatalf("genre = %q, want %q", got, "Pop")
-	}
-}
-
-func TestSelectMusicBrainzAlbumArtistPrefersMatchingRelease(t *testing.T) {
-	releases := []musicBrainzRelease{
-		{
-			Title: "Other Album",
-			ArtistCredit: []musicBrainzArtistCredit{
-				{Name: "Wrong Artist"},
-			},
-		},
-		{
-			Title: "Target Album",
-			ArtistCredit: []musicBrainzArtistCredit{
-				{Name: "Artist A", JoinPhrase: " & "},
-				{Name: "Artist B"},
-			},
-		},
-	}
-
-	got := selectMusicBrainzAlbumArtist(releases, "Target Album")
-	if got != "Artist A & Artist B" {
-		t.Fatalf("album artist = %q, want matching release artist credit", got)
-	}
-}
-
-func TestEnrichRequestExtendedMetadataUsesMusicBrainzAlbumArtist(t *testing.T) {
-	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
-	origMusicBrainzGenreFetcher := fetchMusicBrainzGenreByISRC
-	origMusicBrainzAlbumArtistFetcher := fetchMusicBrainzAlbumArtistByISRC
-	defer func() {
-		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
-		fetchMusicBrainzGenreByISRC = origMusicBrainzGenreFetcher
-		fetchMusicBrainzAlbumArtistByISRC = origMusicBrainzAlbumArtistFetcher
-	}()
-
-	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
-		return &AlbumExtendedMetadata{}, nil
-	}
-	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
-		return "", fmt.Errorf("no genre")
-	}
-	fetchMusicBrainzAlbumArtistByISRC = func(isrc string, albumName string) (string, error) {
-		if isrc != "TESTISRC" || albumName != "Target Album" {
-			t.Fatalf("unexpected MusicBrainz args: %q / %q", isrc, albumName)
-		}
-		return "MusicBrainz Album Artist", nil
-	}
-
-	req := DownloadRequest{
-		ISRC:       "TESTISRC",
-		ArtistName: "Track Artist",
-		AlbumName:  "Target Album",
-	}
-
-	enrichRequestExtendedMetadata(&req)
-
-	if req.AlbumArtist != "MusicBrainz Album Artist" {
-		t.Fatalf("album artist = %q, want MusicBrainz value", req.AlbumArtist)
-	}
-}
-
-func TestEnrichRequestExtendedMetadataDoesNotFallbackAlbumArtistToTrackArtist(t *testing.T) {
-	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
-	origMusicBrainzGenreFetcher := fetchMusicBrainzGenreByISRC
-	origMusicBrainzAlbumArtistFetcher := fetchMusicBrainzAlbumArtistByISRC
-	defer func() {
-		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
-		fetchMusicBrainzGenreByISRC = origMusicBrainzGenreFetcher
-		fetchMusicBrainzAlbumArtistByISRC = origMusicBrainzAlbumArtistFetcher
-	}()
-
-	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
-		return &AlbumExtendedMetadata{}, nil
-	}
-	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
-		return "", fmt.Errorf("no genre")
-	}
-	fetchMusicBrainzAlbumArtistByISRC = func(isrc string, albumName string) (string, error) {
-		return "", fmt.Errorf("no album artist")
-	}
-
-	req := DownloadRequest{
-		ISRC:       "TESTISRC",
-		ArtistName: "Track Artist",
-		AlbumName:  "Target Album",
-	}
-
-	enrichRequestExtendedMetadata(&req)
-
-	if req.AlbumArtist != "" {
-		t.Fatalf("album artist = %q, want empty when MusicBrainz has no value", req.AlbumArtist)
-	}
-}
-
-func TestEnrichExtraMetadataByISRCFallsBackToMusicBrainzGenre(t *testing.T) {
-	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
-	origMusicBrainzFetcher := fetchMusicBrainzGenreByISRC
-	defer func() {
-		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
-		fetchMusicBrainzGenreByISRC = origMusicBrainzFetcher
-	}()
-
-	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
-		return nil, nil
-	}
-	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
-		if isrc != "TEST123" {
-			t.Fatalf("unexpected isrc: %q", isrc)
-		}
-		return "Alternative Rock", nil
-	}
-
-	genre := ""
-	label := ""
-	copyright := ""
-	enrichExtraMetadataByISRC("DownloadWithFallback", "TEST123", &genre, &label, &copyright)
-
-	if genre != "Alternative Rock" {
-		t.Fatalf("genre = %q, want fallback genre", genre)
-	}
-	if label != "" {
-		t.Fatalf("label = %q, want empty", label)
-	}
-	if copyright != "" {
-		t.Fatalf("copyright = %q, want empty", copyright)
-	}
-}
-
-func TestEnrichExtraMetadataByISRCPrefersDeezerGenre(t *testing.T) {
-	origDeezerFetcher := fetchDeezerExtendedMetadataByISRC
-	origMusicBrainzFetcher := fetchMusicBrainzGenreByISRC
-	defer func() {
-		fetchDeezerExtendedMetadataByISRC = origDeezerFetcher
-		fetchMusicBrainzGenreByISRC = origMusicBrainzFetcher
-	}()
-
-	musicBrainzCalled := false
-	fetchDeezerExtendedMetadataByISRC = func(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
-		return &AlbumExtendedMetadata{
-			Genre:     "Synthpop",
-			Label:     "EMI",
-			Copyright: "(C) Test",
-		}, nil
-	}
-	fetchMusicBrainzGenreByISRC = func(isrc string) (string, error) {
-		musicBrainzCalled = true
-		return "Rock", nil
-	}
-
-	genre := ""
-	label := ""
-	copyright := ""
-	enrichExtraMetadataByISRC("DownloadWithFallback", "TEST456", &genre, &label, &copyright)
-
-	if genre != "Synthpop" {
-		t.Fatalf("genre = %q, want Deezer genre", genre)
-	}
-	if label != "EMI" {
-		t.Fatalf("label = %q, want Deezer label", label)
-	}
-	if copyright != "(C) Test" {
-		t.Fatalf("copyright = %q, want Deezer copyright", copyright)
-	}
-	if musicBrainzCalled {
-		t.Fatal("expected MusicBrainz not to be called when Deezer already provides genre")
-	}
-}
-
 func TestApplyReEnrichTrackMetadataPreservesExistingReleaseDateWhenCandidateMissing(t *testing.T) {
 	req := reEnrichRequest{
 		SpotifyID:   "spotify-track-id",
@@ -422,7 +193,7 @@ func TestBuildReEnrichFFmpegMetadataOmitsEmptyFields(t *testing.T) {
 		Copyright:   "",
 	}
 
-	metadata := buildReEnrichFFmpegMetadata(&req, "")
+	metadata := buildReEnrichFFmpegMetadata(req, "")
 
 	if metadata["TITLE"] != "Song" {
 		t.Fatalf("title = %q", metadata["TITLE"])
@@ -451,75 +222,3 @@ func TestBuildReEnrichFFmpegMetadataOmitsEmptyFields(t *testing.T) {
 		}
 	}
 }
-
-func TestBuildReEnrichSearchQuerySkipsPlaceholderArtist(t *testing.T) {
-	req := reEnrichRequest{
-		TrackName:  "Sign of the Times",
-		ArtistName: "Unknown Artist",
-		AlbumName:  "Harry Styles",
-	}
-
-	query := buildReEnrichSearchQuery(req)
-	if query != "Sign of the Times" {
-		t.Fatalf("query = %q", query)
-	}
-
-	req = reEnrichRequest{
-		TrackName:  "Unknown Title",
-		ArtistName: "Unknown Artist",
-		AlbumName:  "Harry Styles",
-	}
-	query = buildReEnrichSearchQuery(req)
-	if query != "Harry Styles" {
-		t.Fatalf("fallback album query = %q", query)
-	}
-}
-
-func TestApplyReEnrichTrackMetadataCopiesComposerAndTotals(t *testing.T) {
-	req := reEnrichRequest{}
-
-	applyReEnrichTrackMetadata(&req, ExtTrackMetadata{
-		Name:        "Resolved Song",
-		Artists:     "Resolved Artist",
-		TrackNumber: 7,
-		TotalTracks: 12,
-		DiscNumber:  2,
-		TotalDiscs:  3,
-		Composer:    "Composer",
-	})
-
-	if req.TrackNumber != 7 || req.TotalTracks != 12 {
-		t.Fatalf("track metadata = %d/%d", req.TrackNumber, req.TotalTracks)
-	}
-	if req.DiscNumber != 2 || req.TotalDiscs != 3 {
-		t.Fatalf("disc metadata = %d/%d", req.DiscNumber, req.TotalDiscs)
-	}
-	if req.TrackName != "Resolved Song" || req.ArtistName != "Resolved Artist" {
-		t.Fatalf("basic tags = %q / %q", req.TrackName, req.ArtistName)
-	}
-	if req.Composer != "Composer" {
-		t.Fatalf("composer = %q", req.Composer)
-	}
-}
-
-func TestBuildReEnrichFFmpegMetadataFormatsTotalsAndComposer(t *testing.T) {
-	req := reEnrichRequest{
-		TrackNumber: 7,
-		TotalTracks: 12,
-		DiscNumber:  2,
-		TotalDiscs:  3,
-		Composer:    "Composer",
-	}
-
-	metadata := buildReEnrichFFmpegMetadata(&req, "")
-
-	if metadata["TRACKNUMBER"] != "7/12" {
-		t.Fatalf("TRACKNUMBER = %q", metadata["TRACKNUMBER"])
-	}
-	if metadata["DISCNUMBER"] != "2/3" {
-		t.Fatalf("DISCNUMBER = %q", metadata["DISCNUMBER"])
-	}
-	if metadata["COMPOSER"] != "Composer" {
-		t.Fatalf("COMPOSER = %q", metadata["COMPOSER"])
-	}
-}

go_backend/extension_health.go

@@ -1,332 +0,0 @@
-package gobackend
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"io"
-	"net/http"
-	"net/url"
-	"strings"
-	"time"
-)
-
-const (
-	extensionHealthDefaultTimeout = 4 * time.Second
-	extensionHealthMaxBodyBytes   = 64 * 1024
-)
-
-type ExtensionHealthResult struct {
-	ExtensionID string                       `json:"extension_id"`
-	Status      string                       `json:"status"`
-	CheckedAt   string                       `json:"checked_at"`
-	Checks      []ExtensionHealthCheckResult `json:"checks"`
-}
-
-type ExtensionHealthCheckResult struct {
-	ID         string `json:"id"`
-	Label      string `json:"label,omitempty"`
-	URL        string `json:"url"`
-	Method     string `json:"method"`
-	ServiceKey string `json:"service_key,omitempty"`
-	Required   bool   `json:"required"`
-	Status     string `json:"status"`
-	HTTPStatus int    `json:"http_status,omitempty"`
-	LatencyMs  int64  `json:"latency_ms"`
-	Message    string `json:"message,omitempty"`
-	Error      string `json:"error,omitempty"`
-	CheckedAt  string `json:"checked_at"`
-}
-
-func CheckExtensionHealthJSON(extensionID string) (string, error) {
-	manager := getExtensionManager()
-	ext, err := manager.GetExtension(extensionID)
-	if err != nil {
-		return "", err
-	}
-
-	result := CheckExtensionHealth(ext)
-	bytes, err := json.Marshal(result)
-	if err != nil {
-		return "", err
-	}
-	return string(bytes), nil
-}
-
-func CheckExtensionHealth(ext *loadedExtension) ExtensionHealthResult {
-	now := time.Now().UTC().Format(time.RFC3339)
-	result := ExtensionHealthResult{
-		ExtensionID: "",
-		Status:      "unsupported",
-		CheckedAt:   now,
-		Checks:      []ExtensionHealthCheckResult{},
-	}
-	if ext == nil || ext.Manifest == nil {
-		result.Status = "offline"
-		return result
-	}
-
-	result.ExtensionID = ext.ID
-	checks := ext.Manifest.ServiceHealth
-	if len(checks) == 0 {
-		return result
-	}
-
-	result.Status = "online"
-	for _, check := range checks {
-		checkResult := runExtensionHealthCheck(ext.Manifest, check)
-		result.Checks = append(result.Checks, checkResult)
-
-		switch checkResult.Status {
-		case "offline":
-			if check.Required {
-				result.Status = "offline"
-			} else if result.Status == "online" {
-				result.Status = "degraded"
-			}
-		case "degraded":
-			if result.Status == "online" {
-				result.Status = "degraded"
-			}
-		case "unknown":
-			if result.Status == "online" {
-				result.Status = "unknown"
-			}
-		}
-	}
-
-	return result
-}
-
-func runExtensionHealthCheck(manifest *ExtensionManifest, check ExtensionHealthCheck) ExtensionHealthCheckResult {
-	method := strings.ToUpper(strings.TrimSpace(check.Method))
-	if method == "" {
-		method = http.MethodGet
-	}
-	now := time.Now().UTC().Format(time.RFC3339)
-	result := ExtensionHealthCheckResult{
-		ID:         check.ID,
-		Label:      check.Label,
-		URL:        check.URL,
-		Method:     method,
-		ServiceKey: strings.TrimSpace(check.ServiceKey),
-		Required:   check.Required,
-		Status:     "unknown",
-		CheckedAt:  now,
-	}
-
-	parsed, err := url.Parse(check.URL)
-	if err != nil {
-		result.Status = "offline"
-		result.Error = fmt.Sprintf("invalid health URL: %v", err)
-		return result
-	}
-	if parsed.Scheme != "https" {
-		result.Status = "offline"
-		result.Error = "health check must use https"
-		return result
-	}
-	host := parsed.Hostname()
-	if host == "" {
-		result.Status = "offline"
-		result.Error = "health check URL hostname is required"
-		return result
-	}
-	if isPrivateIP(host) {
-		result.Status = "offline"
-		result.Error = "private/local health check host is not allowed"
-		return result
-	}
-	if manifest == nil || !manifest.IsDomainAllowed(host) {
-		result.Status = "offline"
-		result.Error = fmt.Sprintf("health check host '%s' is not in extension network permissions", host)
-		return result
-	}
-	if method != http.MethodGet && method != http.MethodHead {
-		result.Status = "offline"
-		result.Error = "health check method must be GET or HEAD"
-		return result
-	}
-
-	timeout := extensionHealthDefaultTimeout
-	if check.TimeoutMs > 0 {
-		timeout = time.Duration(check.TimeoutMs) * time.Millisecond
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
-	defer cancel()
-
-	req, err := http.NewRequestWithContext(ctx, method, check.URL, nil)
-	if err != nil {
-		result.Status = "offline"
-		result.Error = err.Error()
-		return result
-	}
-	req.Header.Set("Accept", "application/json")
-	req.Header.Set("User-Agent", userAgentForURL(parsed))
-
-	start := time.Now()
-	resp, err := NewMetadataHTTPClient(timeout).Do(req)
-	result.LatencyMs = time.Since(start).Milliseconds()
-	if err != nil {
-		result.Status = "offline"
-		result.Error = err.Error()
-		return result
-	}
-	defer resp.Body.Close()
-
-	result.HTTPStatus = resp.StatusCode
-	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		result.Status = "offline"
-		result.Message = resp.Status
-		return result
-	}
-
-	if method == http.MethodHead {
-		result.Status = "online"
-		result.Message = resp.Status
-		return result
-	}
-
-	body, err := io.ReadAll(io.LimitReader(resp.Body, extensionHealthMaxBodyBytes))
-	if err != nil {
-		result.Status = "degraded"
-		result.Error = err.Error()
-		return result
-	}
-
-	status, message := classifyExtensionHealthBody(body, check.ServiceKey)
-	result.Status = status
-	if message == "" {
-		result.Message = resp.Status
-	} else {
-		result.Message = message
-	}
-	return result
-}
-
-func classifyExtensionHealthBody(body []byte, serviceKey string) (string, string) {
-	if len(strings.TrimSpace(string(body))) == 0 {
-		return "online", ""
-	}
-
-	var payload map[string]interface{}
-	if err := json.Unmarshal(body, &payload); err != nil {
-		return "online", ""
-	}
-
-	serviceKey = strings.TrimSpace(serviceKey)
-	if serviceKey != "" {
-		if status, message, ok := classifyExtensionHealthService(payload, serviceKey); ok {
-			return status, message
-		}
-	}
-
-	rawStatus, _ := payload["status"].(string)
-	normalized := strings.ToLower(strings.TrimSpace(rawStatus))
-	switch normalized {
-	case "", "ok", "up", "online", "healthy", "operational", "pass", "passing":
-		return "online", rawStatus
-	case "degraded", "partial", "warning", "warn":
-		return "degraded", rawStatus
-	case "down", "offline", "error", "failed", "fail", "unhealthy":
-		return "offline", rawStatus
-	default:
-		return "online", rawStatus
-	}
-}
-
-func classifyExtensionHealthService(payload map[string]interface{}, serviceKey string) (string, string, bool) {
-	rawServices, ok := payload["services"]
-	if !ok {
-		return "", "", false
-	}
-	services, ok := rawServices.(map[string]interface{})
-	if !ok {
-		return "", "", false
-	}
-	rawService, ok := services[serviceKey]
-	if !ok {
-		return "unknown", fmt.Sprintf("service '%s' not found", serviceKey), true
-	}
-	service, ok := rawService.(map[string]interface{})
-	if !ok {
-		return "unknown", fmt.Sprintf("service '%s' has invalid health payload", serviceKey), true
-	}
-
-	label, _ := service["label"].(string)
-	detail, _ := service["detail"].(string)
-	errText, _ := service["error"].(string)
-	messageParts := []string{}
-	if strings.TrimSpace(label) != "" {
-		messageParts = append(messageParts, strings.TrimSpace(label))
-	}
-	if strings.TrimSpace(detail) != "" {
-		messageParts = append(messageParts, strings.TrimSpace(detail))
-	}
-	if strings.TrimSpace(errText) != "" {
-		messageParts = append(messageParts, strings.TrimSpace(errText))
-	}
-
-	rawStatus, hasStatus := service["status"]
-	okValue, hasOK := service["ok"].(bool)
-	if statusCode, ok := healthNumber(rawStatus); ok {
-		if statusCode >= 200 && statusCode < 300 {
-			return "online", strings.Join(messageParts, ": "), true
-		}
-		if statusCode == http.StatusUnauthorized || statusCode == http.StatusForbidden {
-			return "degraded", strings.Join(messageParts, ": "), true
-		}
-		if statusCode == http.StatusInternalServerError && hasOK && okValue {
-			return "online", strings.Join(messageParts, ": "), true
-		}
-		return "offline", strings.Join(messageParts, ": "), true
-	}
-
-	if isExtensionHealthAuthRequired(detail) {
-		return "degraded", strings.Join(messageParts, ": "), true
-	}
-	if hasOK {
-		if okValue {
-			return "online", strings.Join(messageParts, ": "), true
-		}
-		return "offline", strings.Join(messageParts, ": "), true
-	}
-	if !hasStatus {
-		return "unknown", strings.Join(messageParts, ": "), true
-	}
-
-	statusString := strings.ToLower(strings.TrimSpace(fmt.Sprintf("%v", rawStatus)))
-	switch statusString {
-	case "ok", "up", "online", "healthy", "operational":
-		return "online", strings.Join(messageParts, ": "), true
-	case "degraded", "partial", "warning", "warn":
-		return "degraded", strings.Join(messageParts, ": "), true
-	case "down", "offline", "error", "failed", "fail", "unhealthy":
-		return "offline", strings.Join(messageParts, ": "), true
-	default:
-		return "unknown", strings.Join(messageParts, ": "), true
-	}
-}
-
-func isExtensionHealthAuthRequired(detail string) bool {
-	switch strings.ToLower(strings.TrimSpace(detail)) {
-	case "auth_required", "authorization_required", "login_required", "unauthorized":
-		return true
-	default:
-		return false
-	}
-}
-
-func healthNumber(value interface{}) (int, bool) {
-	switch v := value.(type) {
-	case float64:
-		return int(v), true
-	case int:
-		return v, true
-	case json.Number:
-		n, err := v.Int64()
-		return int(n), err == nil
-	default:
-		return 0, false
-	}
-}

go_backend/extension_health_misc_supplement_test.go

@@ -1,143 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"io"
-	"net/http"
-	"strings"
-	"testing"
-)
-
-func TestExtensionHealthClassificationAndValidation(t *testing.T) {
-	if status, msg := classifyExtensionHealthBody([]byte(`{"status":"degraded"}`), ""); status != "degraded" || msg != "degraded" {
-		t.Fatalf("status/message = %q/%q", status, msg)
-	}
-	if status, _ := classifyExtensionHealthBody([]byte(`not-json`), ""); status != "online" {
-		t.Fatalf("invalid JSON status = %q", status)
-	}
-	if status, msg := classifyExtensionHealthBody([]byte(`{"services":{"tidal":{"status":401,"label":"Tidal","detail":"auth_required"}}}`), "tidal"); status != "degraded" || !strings.Contains(msg, "Tidal") {
-		t.Fatalf("service status/message = %q/%q", status, msg)
-	}
-	if status, msg, ok := classifyExtensionHealthService(map[string]interface{}{"services": map[string]interface{}{}}, "missing"); !ok || status != "unknown" || !strings.Contains(msg, "missing") {
-		t.Fatalf("missing service = %q/%q/%v", status, msg, ok)
-	}
-	if n, ok := healthNumber(json.Number("503")); !ok || n != 503 {
-		t.Fatalf("health number = %d/%v", n, ok)
-	}
-	if !isExtensionHealthAuthRequired(" unauthorized ") {
-		t.Fatal("expected auth required")
-	}
-
-	if result := CheckExtensionHealth(nil); result.Status != "offline" {
-		t.Fatalf("nil health = %#v", result)
-	}
-	manifest := &ExtensionManifest{Permissions: ExtensionPermissions{Network: []string{"status.example.com"}}}
-	invalidURL := runExtensionHealthCheck(manifest, ExtensionHealthCheck{ID: "bad", URL: "://bad"})
-	if invalidURL.Status != "offline" {
-		t.Fatalf("invalid URL = %#v", invalidURL)
-	}
-	insecure := runExtensionHealthCheck(manifest, ExtensionHealthCheck{ID: "http", URL: "http://status.example.com"})
-	if insecure.Status != "offline" || !strings.Contains(insecure.Error, "https") {
-		t.Fatalf("insecure = %#v", insecure)
-	}
-	disallowedHost := runExtensionHealthCheck(manifest, ExtensionHealthCheck{ID: "host", URL: "https://other.example.com"})
-	if disallowedHost.Status != "offline" || !strings.Contains(disallowedHost.Error, "permissions") {
-		t.Fatalf("host = %#v", disallowedHost)
-	}
-	badMethod := runExtensionHealthCheck(manifest, ExtensionHealthCheck{ID: "method", URL: "https://status.example.com", Method: "POST"})
-	if badMethod.Status != "offline" || !strings.Contains(badMethod.Error, "method") {
-		t.Fatalf("method = %#v", badMethod)
-	}
-
-	ext := &loadedExtension{
-		ID: "health-ext",
-		Manifest: &ExtensionManifest{
-			ServiceHealth: []ExtensionHealthCheck{
-				{ID: "required", URL: "http://status.example.com", Required: true},
-				{ID: "optional", URL: "http://status.example.com", Required: false},
-			},
-		},
-	}
-	if result := CheckExtensionHealth(ext); result.Status != "offline" || len(result.Checks) != 2 {
-		t.Fatalf("extension health = %#v", result)
-	}
-}
-
-func TestCoverRomajiParallelAndIDHSHelpers(t *testing.T) {
-	spotify := "https://i.scdn.co/image/ab67616d00001e02abcdef"
-	if got := GetCoverFromSpotify(spotify, true); !strings.Contains(got, spotifySizeMax) {
-		t.Fatalf("spotify cover = %q", got)
-	}
-	if got := upgradeToMaxQuality("https://cdn-images.dzcdn.net/images/cover/abc/500x500-000000-80-0-0.jpg"); !strings.Contains(got, "1800x1800") {
-		t.Fatalf("deezer cover = %q", got)
-	}
-	if got := upgradeToMaxQuality("https://resources.tidal.com/images/id/320x320.jpg"); !strings.Contains(got, "origin.jpg") {
-		t.Fatalf("tidal cover = %q", got)
-	}
-	if got := upgradeToMaxQuality("https://static.qobuz.com/images/covers/ab/cd/foo_600.jpg"); !strings.Contains(got, "_max.jpg") {
-		t.Fatalf("qobuz cover = %q", got)
-	}
-	if data, err := downloadCoverToMemory("", false); err == nil || data != nil {
-		t.Fatalf("expected empty cover error")
-	}
-
-	if !ContainsJapanese("カタカナ") || ContainsJapanese("abc") {
-		t.Fatal("unexpected Japanese detection")
-	}
-	if got := JapaneseToRomaji("きゃット"); got != "kyatto" {
-		t.Fatalf("romaji = %q", got)
-	}
-	if got := BuildSearchQuery("きゃ! song", "アーティスト"); got != "atisuto kya song" {
-		t.Fatalf("query = %q", got)
-	}
-	if got := CleanToASCII("A, B. C!"); got != "A B C" {
-		t.Fatalf("ascii = %q", got)
-	}
-
-	if err := PreWarmCache(`not-json`); err == nil {
-		t.Fatal("expected prewarm JSON error")
-	}
-	if err := PreWarmCache(`[{"isrc":"ISRC","track_name":"Song","artist_name":"Artist","spotify_id":"sp","service":"tidal"}]`); err != nil {
-		t.Fatalf("PreWarmCache: %v", err)
-	}
-	if result := FetchCoverAndLyricsParallel("", false, "", "", "", false, 0); result == nil || result.CoverErr != nil || result.LyricsErr != nil {
-		t.Fatalf("parallel result = %#v", result)
-	}
-	if ClearTrackCache(); GetCacheSize() != 0 {
-		t.Fatal("expected empty cache size")
-	}
-
-	client := &IDHSClient{client: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		if req.Method != http.MethodPost {
-			t.Fatalf("method = %s", req.Method)
-		}
-		body := `{"id":"1","type":"song","title":"Song","links":[{"type":"tidal","url":"https://tidal.com/browse/track/7"},{"type":"deezer","url":"https://www.deezer.com/track/9"},{"type":"spotify","url":"https://open.spotify.com/track/abc"}]}`
-		return &http.Response{
-			StatusCode: 200,
-			Header:     make(http.Header),
-			Body:       io.NopCloser(strings.NewReader(body)),
-			Request:    req,
-		}, nil
-	})}}
-	availability, err := client.GetAvailabilityFromSpotify("spotify-track")
-	if err != nil {
-		t.Fatalf("GetAvailabilityFromSpotify: %v", err)
-	}
-	if !availability.Tidal || !availability.Deezer || availability.DeezerID != "9" {
-		t.Fatalf("spotify availability = %#v", availability)
-	}
-	deezerAvailability, err := client.GetAvailabilityFromDeezer("9")
-	if err != nil {
-		t.Fatalf("GetAvailabilityFromDeezer: %v", err)
-	}
-	if deezerAvailability.SpotifyID != "abc" || !deezerAvailability.Tidal {
-		t.Fatalf("deezer availability = %#v", deezerAvailability)
-	}
-
-	errorClient := &IDHSClient{client: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		return &http.Response{StatusCode: 429, Body: io.NopCloser(strings.NewReader("")), Request: req}, nil
-	})}}
-	if _, err := errorClient.Search("bad", nil); err == nil {
-		t.Fatal("expected rate limit error")
-	}
-}

go_backend/extension_manager.go

@@ -10,7 +10,6 @@ import (
 	"strconv"
 	"strings"
 	"sync"
-	"time"
 
 	"github.com/dop251/goja"
 )
@@ -44,12 +43,12 @@ func compareVersions(v1, v2 string) int {
 	return 0
 }
 
-type loadedExtension struct {
+type LoadedExtension struct {
 	ID          string             `json:"id"`
 	Manifest    *ExtensionManifest `json:"manifest"`
 	VM          *goja.Runtime      `json:"-"`
 	VMMu        sync.Mutex         `json:"-"`
-	runtime     *extensionRuntime
+	runtime     *ExtensionRuntime
 	initialized bool
 	Enabled     bool   `json:"enabled"`
 	Error       string `json:"error,omitempty"`
@@ -74,7 +73,7 @@ func getExtensionInitSettings(extensionID string) map[string]interface{} {
 	return filtered
 }
 
-func ensureRuntimeReadyLocked(ext *loadedExtension, applyStoredSettings bool) error {
+func ensureRuntimeReadyLocked(ext *LoadedExtension, applyStoredSettings bool) error {
 	if ext.VM == nil || ext.runtime == nil {
 		if err := initializeVMLocked(ext); err != nil {
 			ext.Error = err.Error()
@@ -101,14 +100,14 @@ func ensureRuntimeReadyLocked(ext *loadedExtension, applyStoredSettings bool) er
 	return nil
 }
 
-func (ext *loadedExtension) ensureRuntimeReady() error {
+func (ext *LoadedExtension) ensureRuntimeReady() error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 
 	return ensureRuntimeReadyLocked(ext, true)
 }
 
-func (ext *loadedExtension) lockReadyVM() (*goja.Runtime, error) {
+func (ext *LoadedExtension) lockReadyVM() (*goja.Runtime, error) {
 	ext.VMMu.Lock()
 	if err := ensureRuntimeReadyLocked(ext, true); err != nil {
 		ext.VMMu.Unlock()
@@ -117,28 +116,28 @@ func (ext *loadedExtension) lockReadyVM() (*goja.Runtime, error) {
 	return ext.VM, nil
 }
 
-type extensionManager struct {
+type ExtensionManager struct {
 	mu            sync.RWMutex
-	extensions    map[string]*loadedExtension
+	extensions    map[string]*LoadedExtension
 	extensionsDir string
 	dataDir       string
 }
 
 var (
-	globalExtManager     *extensionManager
+	globalExtManager     *ExtensionManager
 	globalExtManagerOnce sync.Once
 )
 
-func getExtensionManager() *extensionManager {
+func GetExtensionManager() *ExtensionManager {
 	globalExtManagerOnce.Do(func() {
-		globalExtManager = &extensionManager{
-			extensions: make(map[string]*loadedExtension),
+		globalExtManager = &ExtensionManager{
+			extensions: make(map[string]*LoadedExtension),
 		}
 	})
 	return globalExtManager
 }
 
-func (m *extensionManager) SetDirectories(extensionsDir, dataDir string) error {
+func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -155,14 +154,14 @@ func (m *extensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	return nil
 }
 
-func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtension, error) {
+func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtension, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
-		return nil, fmt.Errorf("invalid file format: please select a .spotiflac-ext file")
+		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
 
 	zipReader, err := zip.OpenReader(filePath)
 	if err != nil {
-		return nil, fmt.Errorf("cannot open extension file: the file may be corrupted or not a valid extension package")
+		return nil, fmt.Errorf("Cannot open extension file. The file may be corrupted or not a valid extension package")
 	}
 	defer zipReader.Close()
 
@@ -187,16 +186,16 @@ func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtens
 	}
 
 	if manifestData == nil {
-		return nil, fmt.Errorf("invalid extension package: manifest.json not found")
+		return nil, fmt.Errorf("Invalid extension package: manifest.json not found")
 	}
 
 	if !hasIndexJS {
-		return nil, fmt.Errorf("invalid extension package: index.js not found")
+		return nil, fmt.Errorf("Invalid extension package: index.js not found")
 	}
 
 	manifest, err := ParseManifest(manifestData)
 	if err != nil {
-		return nil, fmt.Errorf("invalid extension manifest: %w", err)
+		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
 	m.mu.RLock()
@@ -214,9 +213,9 @@ func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtens
 		if versionCompare > 0 {
 			return m.UpgradeExtension(filePath)
 		} else if versionCompare == 0 {
-			return nil, fmt.Errorf("extension '%s' v%s is already installed", existingDisplayName, existingVersion)
+			return nil, fmt.Errorf("Extension '%s' v%s is already installed", existingDisplayName, existingVersion)
 		} else {
-			return nil, fmt.Errorf("cannot downgrade '%s' from v%s to v%s", existingDisplayName, existingVersion, manifest.Version)
+			return nil, fmt.Errorf("Cannot downgrade '%s' from v%s to v%s", existingDisplayName, existingVersion, manifest.Version)
 		}
 	}
 
@@ -224,7 +223,7 @@ func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtens
 	defer m.mu.Unlock()
 
 	if _, exists := m.extensions[manifest.Name]; exists {
-		return nil, fmt.Errorf("extension '%s' was installed by another process", manifest.DisplayName)
+		return nil, fmt.Errorf("Extension '%s' was installed by another process", manifest.DisplayName)
 	}
 
 	extDir := filepath.Join(m.extensionsDir, manifest.Name)
@@ -273,7 +272,7 @@ func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtens
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
 		Enabled:   false, // New extensions start disabled
@@ -293,7 +292,7 @@ func (m *extensionManager) LoadExtensionFromFile(filePath string) (*loadedExtens
 	return ext, nil
 }
 
-func initializeVMLocked(ext *loadedExtension) error {
+func initializeVMLocked(ext *LoadedExtension) error {
 	ext.VM = nil
 	ext.runtime = nil
 	ext.initialized = false
@@ -306,7 +305,7 @@ func initializeVMLocked(ext *loadedExtension) error {
 		return fmt.Errorf("failed to read index.js: %w", err)
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 	ext.runtime = runtime
 	runtime.RegisterAPIs(vm)
 	runtime.RegisterGoBackendAPIs(vm)
@@ -343,90 +342,23 @@ func initializeVMLocked(ext *loadedExtension) error {
 	return nil
 }
 
-func newIsolatedExtensionRuntime(ext *loadedExtension) (*goja.Runtime, *extensionRuntime, error) {
-	vm := goja.New()
-
-	indexPath := filepath.Join(ext.SourceDir, "index.js")
-	jsCode, err := os.ReadFile(indexPath)
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed to read index.js: %w", err)
-	}
-
-	runtime := &extensionRuntime{
-		extensionID:       ext.ID,
-		manifest:          ext.Manifest,
-		settings:          make(map[string]interface{}),
-		cookieJar:         nil,
-		dataDir:           ext.DataDir,
-		vm:                vm,
-		storageFlushDelay: defaultStorageFlushDelay,
-	}
-	if ext.runtime != nil && ext.runtime.cookieJar != nil {
-		runtime.cookieJar = ext.runtime.cookieJar
-	} else {
-		jar, _ := newSimpleCookieJar()
-		runtime.cookieJar = jar
-	}
-	runtime.httpClient = newExtensionHTTPClient(ext, runtime.cookieJar, extensionHTTPTimeout(ext, 30*time.Second))
-	runtime.downloadClient = newExtensionHTTPClient(ext, runtime.cookieJar, DownloadTimeout)
-	runtime.RegisterAPIs(vm)
-	runtime.RegisterGoBackendAPIs(vm)
-
-	console := vm.NewObject()
-	console.Set("log", func(call goja.FunctionCall) goja.Value {
-		args := make([]interface{}, len(call.Arguments))
-		for i, arg := range call.Arguments {
-			args[i] = arg.Export()
-		}
-		GoLog("[Extension:%s] %v\n", ext.ID, args)
-		return goja.Undefined()
-	})
-	vm.Set("console", console)
-
-	var registeredExtension goja.Value
-	vm.Set("registerExtension", func(call goja.FunctionCall) goja.Value {
-		if len(call.Arguments) > 0 {
-			registeredExtension = call.Arguments[0]
-			vm.Set("extension", call.Arguments[0])
-		}
-		return goja.Undefined()
-	})
-
-	if _, err := vm.RunString(string(jsCode)); err != nil {
-		runtime.closeStorageFlusher()
-		return nil, nil, fmt.Errorf("failed to execute extension code: %w", err)
-	}
-
-	if registeredExtension == nil || goja.IsUndefined(registeredExtension) {
-		runtime.closeStorageFlusher()
-		return nil, nil, fmt.Errorf("extension did not call registerExtension()")
-	}
-
-	settings := getExtensionInitSettings(ext.ID)
-	if len(settings) > 0 {
-		if err := initializeExtensionRuntimeWithSettings(vm, ext.ID, settings); err != nil {
-			runtime.closeStorageFlusher()
-			return nil, nil, err
-		}
-	}
-
-	return vm, runtime, nil
-}
-
-func (m *extensionManager) initializeVM(ext *loadedExtension) error {
+func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 	return initializeVMLocked(ext)
 }
 
-func initializeExtensionRuntimeWithSettings(
-	vm *goja.Runtime,
-	extensionID string,
+func initializeExtensionWithSettingsLocked(
+	ext *LoadedExtension,
 	settings map[string]interface{},
 ) error {
+	if ext.VM == nil {
+		return fmt.Errorf("Extension failed to load. Please reinstall the extension")
+	}
+
 	settingsJSON, err := json.Marshal(settings)
 	if err != nil {
-		return fmt.Errorf("failed to save settings")
+		return fmt.Errorf("Failed to save settings")
 	}
 
 	script := fmt.Sprintf(`
@@ -444,9 +376,11 @@ func initializeExtensionRuntimeWithSettings(
 		})()
 	`, string(settingsJSON))
 
-	result, err := vm.RunString(script)
+	result, err := ext.VM.RunString(script)
 	if err != nil {
-		GoLog("[Extension] Initialize error for %s: %v\n", extensionID, err)
+		ext.Error = fmt.Sprintf("initialize failed: %v", err)
+		ext.Enabled = false
+		GoLog("[Extension] Initialize error for %s: %v\n", ext.ID, err)
 		return err
 	}
 
@@ -458,87 +392,61 @@ func initializeExtensionRuntimeWithSettings(
 				if e, ok := resultMap["error"].(string); ok {
 					errMsg = e
 				}
-				GoLog("[Extension] Initialize failed for %s: %s\n", extensionID, errMsg)
+				ext.Error = errMsg
+				ext.Enabled = false
+				GoLog("[Extension] Initialize failed for %s: %s\n", ext.ID, errMsg)
 				return fmt.Errorf("initialize failed: %s", errMsg)
 			}
 		}
 	}
 
-	return nil
-}
-
-func initializeExtensionWithSettingsLocked(
-	ext *loadedExtension,
-	settings map[string]interface{},
-) error {
-	if ext.VM == nil {
-		return fmt.Errorf("extension failed to load: please reinstall the extension")
-	}
-
-	if err := initializeExtensionRuntimeWithSettings(ext.VM, ext.ID, settings); err != nil {
-		ext.Error = err.Error()
-		ext.Enabled = false
-		return err
-	}
-
 	ext.initialized = true
 	GoLog("[Extension] Initialized %s\n", ext.ID)
 	return nil
 }
 
-func runCleanupLocked(ext *loadedExtension) error {
+func runCleanupLocked(ext *LoadedExtension) error {
 	if ext.VM != nil {
-		if err := runCleanupOnVM(ext.VM); err != nil {
+		script := `
+			(function() {
+				if (typeof extension !== 'undefined' && typeof extension.cleanup === 'function') {
+					try {
+						extension.cleanup();
+						return { success: true };
+					} catch (e) {
+						return { success: false, error: e.toString() };
+					}
+				}
+				return { success: true, message: 'no cleanup function' };
+			})()
+		`
+
+		result, err := ext.VM.RunString(script)
+		if err != nil {
 			return err
 		}
-		if ext.VM.Get("extension") != nil {
+
+		if result != nil && !goja.IsUndefined(result) {
+			exported := result.Export()
+			if resultMap, ok := exported.(map[string]interface{}); ok {
+				if success, ok := resultMap["success"].(bool); ok && !success {
+					errMsg := "unknown error"
+					if e, ok := resultMap["error"].(string); ok {
+						errMsg = e
+					}
+					return fmt.Errorf("cleanup failed: %s", errMsg)
+				}
+			}
+		}
+
+		if result != nil && !goja.IsUndefined(result) && !goja.IsNull(result) {
 			GoLog("[Extension] Cleanup called for %s\n", ext.ID)
 		}
 	}
 	return nil
 }
 
-func runCleanupOnVM(vm *goja.Runtime) error {
-	if vm == nil {
-		return nil
-	}
-
-	script := `
-		(function() {
-			if (typeof extension !== 'undefined' && typeof extension.cleanup === 'function') {
-				try {
-					extension.cleanup();
-					return { success: true };
-				} catch (e) {
-					return { success: false, error: e.toString() };
-				}
-			}
-			return { success: true, message: 'no cleanup function' };
-		})()
-	`
-
-	result, err := vm.RunString(script)
-	if err != nil {
-		return err
-	}
-
-	if result != nil && !goja.IsUndefined(result) {
-		exported := result.Export()
-		if resultMap, ok := exported.(map[string]interface{}); ok {
-			if success, ok := resultMap["success"].(bool); ok && !success {
-				errMsg := "unknown error"
-				if e, ok := resultMap["error"].(string); ok {
-					errMsg = e
-				}
-				return fmt.Errorf("cleanup failed: %s", errMsg)
-			}
-		}
-	}
-
-	return nil
-}
-
-func teardownVMLocked(ext *loadedExtension) {
+func teardownVMLocked(ext *LoadedExtension) {
 	if err := runCleanupLocked(ext); err != nil {
 		GoLog("[Extension] Error calling cleanup for %s: %v\n", ext.ID, err)
 	}
@@ -553,7 +461,7 @@ func teardownVMLocked(ext *loadedExtension) {
 	ext.initialized = false
 }
 
-func validateExtensionLoad(ext *loadedExtension) error {
+func validateExtensionLoad(ext *LoadedExtension) error {
 	ext.VMMu.Lock()
 	defer ext.VMMu.Unlock()
 
@@ -564,13 +472,13 @@ func validateExtensionLoad(ext *loadedExtension) error {
 	return nil
 }
 
-func (m *extensionManager) UnloadExtension(extensionID string) error {
+func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
 	ext, exists := m.extensions[extensionID]
 	if !exists {
-		return fmt.Errorf("extension not found")
+		return fmt.Errorf("Extension not found")
 	}
 
 	ext.VMMu.Lock()
@@ -583,35 +491,35 @@ func (m *extensionManager) UnloadExtension(extensionID string) error {
 	return nil
 }
 
-func (m *extensionManager) GetExtension(extensionID string) (*loadedExtension, error) {
+func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, error) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
 
 	ext, exists := m.extensions[extensionID]
 	if !exists {
-		return nil, fmt.Errorf("extension not found")
+		return nil, fmt.Errorf("Extension not found")
 	}
 	return ext, nil
 }
 
-func (m *extensionManager) GetAllExtensions() []*loadedExtension {
+func (m *ExtensionManager) GetAllExtensions() []*LoadedExtension {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
 
-	result := make([]*loadedExtension, 0, len(m.extensions))
+	result := make([]*LoadedExtension, 0, len(m.extensions))
 	for _, ext := range m.extensions {
 		result = append(result, ext)
 	}
 	return result
 }
 
-func (m *extensionManager) SetExtensionEnabled(extensionID string, enabled bool) error {
+func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
 	ext, exists := m.extensions[extensionID]
 	if !exists {
-		return fmt.Errorf("extension not found")
+		return fmt.Errorf("Extension not found")
 	}
 
 	if enabled {
@@ -639,7 +547,7 @@ func (m *extensionManager) SetExtensionEnabled(extensionID string, enabled bool)
 	return nil
 }
 
-func (m *extensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
+func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
 	var loaded []string
 	var errors []error
 
@@ -677,7 +585,7 @@ func (m *extensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string
 	return loaded, errors
 }
 
-func (m *extensionManager) loadExtensionFromDirectory(dirPath string) (*loadedExtension, error) {
+func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedExtension, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -689,12 +597,12 @@ func (m *extensionManager) loadExtensionFromDirectory(dirPath string) (*loadedEx
 
 	manifest, err := ParseManifest(manifestData)
 	if err != nil {
-		return nil, fmt.Errorf("invalid extension manifest: %w", err)
+		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
 	indexPath := filepath.Join(dirPath, "index.js")
 	if _, err := os.Stat(indexPath); os.IsNotExist(err) {
-		return nil, fmt.Errorf("extension is missing index.js file")
+		return nil, fmt.Errorf("Extension is missing index.js file")
 	}
 
 	if existing, exists := m.extensions[manifest.Name]; exists {
@@ -707,7 +615,7 @@ func (m *extensionManager) loadExtensionFromDirectory(dirPath string) (*loadedEx
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
 		Enabled:   false, // Will be restored from settings store
@@ -735,7 +643,7 @@ func (m *extensionManager) loadExtensionFromDirectory(dirPath string) (*loadedEx
 	return ext, nil
 }
 
-func (m *extensionManager) RemoveExtension(extensionID string) error {
+func (m *ExtensionManager) RemoveExtension(extensionID string) error {
 	ext, err := m.GetExtension(extensionID)
 	if err != nil {
 		return err
@@ -755,14 +663,14 @@ func (m *extensionManager) RemoveExtension(extensionID string) error {
 }
 
 // Only allows upgrades (new version > current version), not downgrades
-func (m *extensionManager) UpgradeExtension(filePath string) (*loadedExtension, error) {
+func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
-		return nil, fmt.Errorf("invalid file format: please select a .spotiflac-ext file")
+		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
 
 	zipReader, err := zip.OpenReader(filePath)
 	if err != nil {
-		return nil, fmt.Errorf("cannot open extension file: the file may be corrupted or not a valid extension package")
+		return nil, fmt.Errorf("Cannot open extension file. The file may be corrupted or not a valid extension package")
 	}
 	defer zipReader.Close()
 
@@ -787,16 +695,16 @@ func (m *extensionManager) UpgradeExtension(filePath string) (*loadedExtension,
 	}
 
 	if manifestData == nil {
-		return nil, fmt.Errorf("invalid extension package: manifest.json not found")
+		return nil, fmt.Errorf("Invalid extension package: manifest.json not found")
 	}
 
 	if !hasIndexJS {
-		return nil, fmt.Errorf("invalid extension package: index.js not found")
+		return nil, fmt.Errorf("Invalid extension package: index.js not found")
 	}
 
 	newManifest, err := ParseManifest(manifestData)
 	if err != nil {
-		return nil, fmt.Errorf("invalid extension manifest: %w", err)
+		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
 	m.mu.RLock()
@@ -804,15 +712,15 @@ func (m *extensionManager) UpgradeExtension(filePath string) (*loadedExtension,
 	m.mu.RUnlock()
 
 	if !exists {
-		return nil, fmt.Errorf("extension '%s' is not installed; use install instead of upgrade", newManifest.DisplayName)
+		return nil, fmt.Errorf("Extension '%s' is not installed. Use install instead of upgrade.", newManifest.DisplayName)
 	}
 
 	versionCompare := compareVersions(newManifest.Version, existing.Manifest.Version)
 	if versionCompare < 0 {
-		return nil, fmt.Errorf("cannot downgrade extension: current version: %s, new version: %s", existing.Manifest.Version, newManifest.Version)
+		return nil, fmt.Errorf("Cannot downgrade extension. Current version: %s, New version: %s", existing.Manifest.Version, newManifest.Version)
 	}
 	if versionCompare == 0 {
-		return nil, fmt.Errorf("extension is already at version %s", existing.Manifest.Version)
+		return nil, fmt.Errorf("Extension is already at version %s", existing.Manifest.Version)
 	}
 
 	GoLog("[Extension] Upgrading %s from v%s to v%s\n", newManifest.DisplayName, existing.Manifest.Version, newManifest.Version)
@@ -869,7 +777,7 @@ func (m *extensionManager) UpgradeExtension(filePath string) (*loadedExtension,
 		}
 	}
 
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID:        newManifest.Name,
 		Manifest:  newManifest,
 		Enabled:   wasEnabled, // Preserve enabled state from before upgrade
@@ -904,15 +812,15 @@ type ExtensionUpgradeInfo struct {
 	IsInstalled    bool   `json:"is_installed"`
 }
 
-func (m *extensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
+func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
-		return nil, fmt.Errorf("invalid file format: please select a .spotiflac-ext file")
+		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
 
 	zipReader, err := zip.OpenReader(filePath)
 
 	if err != nil {
-		return nil, fmt.Errorf("cannot open extension file")
+		return nil, fmt.Errorf("Cannot open extension file")
 	}
 	defer zipReader.Close()
 
@@ -939,7 +847,7 @@ func (m *extensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 
 	newManifest, err := ParseManifest(manifestData)
 	if err != nil {
-		return nil, fmt.Errorf("invalid manifest: %w", err)
+		return nil, fmt.Errorf("Invalid manifest: %w", err)
 	}
 
 	m.mu.RLock()
@@ -963,7 +871,7 @@ func (m *extensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 	return info, nil
 }
 
-func (m *extensionManager) CheckExtensionUpgradeJSON(filePath string) (string, error) {
+func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, error) {
 	info, err := m.checkExtensionUpgradeInternal(filePath)
 	if err != nil {
 		return "", err
@@ -977,7 +885,7 @@ func (m *extensionManager) CheckExtensionUpgradeJSON(filePath string) (string, e
 	return string(jsonBytes), nil
 }
 
-func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
+func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	extensions := m.GetAllExtensions()
 
 	type ExtensionInfo struct {
@@ -985,6 +893,7 @@ func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 		Name                   string                 `json:"name"`
 		DisplayName            string                 `json:"display_name"`
 		Version                string                 `json:"version"`
+		Author                 string                 `json:"author"`
 		Description            string                 `json:"description"`
 		Homepage               string                 `json:"homepage,omitempty"`
 		IconPath               string                 `json:"icon_path,omitempty"`
@@ -999,12 +908,9 @@ func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 		HasDownloadProvider    bool                   `json:"has_download_provider"`
 		HasLyricsProvider      bool                   `json:"has_lyrics_provider"`
 		SkipMetadataEnrichment bool                   `json:"skip_metadata_enrichment"`
-		SkipLyrics             bool                   `json:"skip_lyrics"`
-		StopProviderFallback   bool                   `json:"stop_provider_fallback"`
 		SearchBehavior         *SearchBehaviorConfig  `json:"search_behavior,omitempty"`
 		TrackMatching          *TrackMatchingConfig   `json:"track_matching,omitempty"`
 		PostProcessing         *PostProcessingConfig  `json:"post_processing,omitempty"`
-		ServiceHealth          []ExtensionHealthCheck `json:"service_health,omitempty"`
 		Capabilities           map[string]interface{} `json:"capabilities,omitempty"`
 	}
 
@@ -1044,6 +950,7 @@ func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 			Name:                   ext.Manifest.Name,
 			DisplayName:            ext.Manifest.DisplayName,
 			Version:                ext.Manifest.Version,
+			Author:                 ext.Manifest.Author,
 			Description:            ext.Manifest.Description,
 			Homepage:               ext.Manifest.Homepage,
 			IconPath:               iconPath,
@@ -1058,12 +965,9 @@ func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 			HasDownloadProvider:    ext.Manifest.IsDownloadProvider(),
 			HasLyricsProvider:      ext.Manifest.IsLyricsProvider(),
 			SkipMetadataEnrichment: ext.Manifest.SkipMetadataEnrichment,
-			SkipLyrics:             ext.Manifest.SkipLyrics,
-			StopProviderFallback:   ext.Manifest.StopsProviderFallback(),
 			SearchBehavior:         ext.Manifest.SearchBehavior,
 			TrackMatching:          ext.Manifest.TrackMatching,
 			PostProcessing:         ext.Manifest.PostProcessing,
-			ServiceHealth:          ext.Manifest.ServiceHealth,
 			Capabilities:           ext.Manifest.Capabilities,
 		}
 	}
@@ -1076,13 +980,13 @@ func (m *extensionManager) GetInstalledExtensionsJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-func (m *extensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
+func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
 	ext, exists := m.extensions[extensionID]
 	if !exists {
-		return fmt.Errorf("extension not found")
+		return fmt.Errorf("Extension not found")
 	}
 
 	ext.VMMu.Lock()
@@ -1094,13 +998,13 @@ func (m *extensionManager) InitializeExtension(extensionID string, settings map[
 	return initializeExtensionWithSettingsLocked(ext, settings)
 }
 
-func (m *extensionManager) CleanupExtension(extensionID string) error {
+func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
 	ext, exists := m.extensions[extensionID]
 	if !exists {
-		return fmt.Errorf("extension not found")
+		return fmt.Errorf("Extension not found")
 	}
 
 	if ext.VM == nil {
@@ -1116,7 +1020,7 @@ func (m *extensionManager) CleanupExtension(extensionID string) error {
 	return nil
 }
 
-func (m *extensionManager) UnloadAllExtensions() {
+func (m *ExtensionManager) UnloadAllExtensions() {
 	m.mu.Lock()
 	extensionIDs := make([]string, 0, len(m.extensions))
 	for id := range m.extensions {
@@ -1131,7 +1035,7 @@ func (m *extensionManager) UnloadAllExtensions() {
 	GoLog("[Extension] All extensions unloaded\n")
 }
 
-func (m *extensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
+func (m *ExtensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
@@ -1140,38 +1044,23 @@ func (m *extensionManager) InvokeAction(extensionID string, actionName string) (
 		return nil, fmt.Errorf("extension not found: %s", extensionID)
 	}
 
+	if err := ext.ensureRuntimeReady(); err != nil {
+		return nil, err
+	}
+
 	if !ext.Enabled {
 		return nil, fmt.Errorf("extension is disabled")
 	}
-	vm, err := ext.lockReadyVM()
-	if err != nil {
-		return nil, err
-	}
-	defer ext.VMMu.Unlock()
 
-	// Merge extension return values onto the top-level JSON object so Flutter can read
-	// message, open_auth_url, setting_updates without unwrapping a nested "result" key.
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.%s === 'function') {
 				try {
 					var result = extension.%s();
 					if (result && typeof result.then === 'function') {
+						// Handle promise - return pending status
 						return { success: true, pending: true, message: 'Action started' };
 					}
-					if (result !== null && result !== undefined && typeof result === 'object') {
-						var isArr = false;
-						if (typeof Array !== 'undefined' && Array.isArray) {
-							isArr = Array.isArray(result);
-						}
-						if (!isArr) {
-							var out = { success: true };
-							for (var k in result) {
-								out[k] = result[k];
-							}
-							return out;
-						}
-					}
 					return { success: true, result: result };
 				} catch (e) {
 					return { success: false, error: e.toString() };
@@ -1181,7 +1070,7 @@ func (m *extensionManager) InvokeAction(extensionID string, actionName string) (
 		})()
 	`, actionName, actionName, actionName)
 
-	result, err := RunWithTimeoutAndRecover(vm, script, DefaultJSTimeout)
+	result, err := RunWithTimeoutAndRecover(ext.VM, script, DefaultJSTimeout)
 	if err != nil {
 		GoLog("[Extension] InvokeAction error for %s.%s: %v\n", extensionID, actionName, err)
 		return nil, fmt.Errorf("action failed: %v", err)

go_backend/extension_manager_supplement_test.go

@@ -1,143 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-func TestExtensionManagerPackageLifecycle(t *testing.T) {
-	dir := t.TempDir()
-	extensionsDir := filepath.Join(dir, "extensions")
-	dataDir := filepath.Join(dir, "data")
-	manager := &extensionManager{extensions: map[string]*loadedExtension{}}
-	if err := manager.SetDirectories(extensionsDir, dataDir); err != nil {
-		t.Fatalf("SetDirectories: %v", err)
-	}
-	if err := GetExtensionSettingsStore().SetDataDir(dataDir); err != nil {
-		t.Fatalf("settings data dir: %v", err)
-	}
-
-	js := `
-var cleaned = false;
-registerExtension({
-  initialize: function(settings) { this.settings = settings || {}; },
-  cleanup: function() { cleaned = true; },
-  doAction: function() { return { message: "done", setting_updates: { quality: "lossless" } }; },
-  getHomeFeed: function() { return [{ id: "home", title: "Home" }]; },
-  getBrowseCategories: function() { return [{ id: "cat", title: "Category" }]; },
-  searchTracks: function() { return { tracks: [], total: 0 }; },
-  fetchLyrics: function() { return { syncType: "UNSYNCED", lines: [{ words: "hello" }] }; },
-  getDownloadUrl: function() { return { url: "https://example.test/a.flac" }; }
-});
-`
-	pkgV1 := filepath.Join(dir, "manager-ext-v1.spotiflac-ext")
-	createTestExtensionPackage(t, pkgV1, "manager-ext", "1.0.0", js, map[string]string{"../unsafe.txt": "skip"})
-	pkgV2 := filepath.Join(dir, "manager-ext-v2.spotiflac-ext")
-	createTestExtensionPackage(t, pkgV2, "manager-ext", "1.1.0", js, nil)
-
-	if compareVersions("v1.2.0", "1.1.9") <= 0 || compareVersions("1.0.0", "1.0") != 0 || compareVersions("1.0.0", "1.0.1") >= 0 {
-		t.Fatal("compareVersions mismatch")
-	}
-	if _, err := manager.LoadExtensionFromFile(filepath.Join(dir, "bad.txt")); err == nil {
-		t.Fatal("expected bad extension suffix error")
-	}
-	if _, err := manager.LoadExtensionFromFile(filepath.Join(dir, "missing.spotiflac-ext")); err == nil {
-		t.Fatal("expected invalid package error")
-	}
-
-	ext, err := manager.LoadExtensionFromFile(pkgV1)
-	if err != nil {
-		t.Fatalf("LoadExtensionFromFile: %v", err)
-	}
-	if ext.ID != "manager-ext" || ext.Enabled || ext.SourceDir == "" {
-		t.Fatalf("loaded extension = %#v", ext)
-	}
-	if _, err := os.Stat(filepath.Join(ext.SourceDir, "unsafe.txt")); err == nil {
-		t.Fatal("unsafe archive path should not be extracted")
-	}
-	if _, err := manager.LoadExtensionFromFile(pkgV1); err == nil {
-		t.Fatal("expected duplicate version error")
-	}
-
-	installedJSON, err := manager.GetInstalledExtensionsJSON()
-	if err != nil || !strings.Contains(installedJSON, "manager-ext") || !strings.Contains(installedJSON, "icon_path") {
-		t.Fatalf("GetInstalledExtensionsJSON = %q/%v", installedJSON, err)
-	}
-	var installed []map[string]interface{}
-	if err := json.Unmarshal([]byte(installedJSON), &installed); err != nil || len(installed) != 1 {
-		t.Fatalf("decode installed = %#v/%v", installed, err)
-	}
-
-	if err := GetExtensionSettingsStore().Set("manager-ext", "quality", "lossless"); err != nil {
-		t.Fatalf("settings Set: %v", err)
-	}
-	if err := manager.SetExtensionEnabled("manager-ext", true); err != nil {
-		t.Fatalf("enable extension: %v", err)
-	}
-	if !ext.Enabled || ext.VM == nil || !ext.initialized {
-		t.Fatalf("enabled extension = %#v", ext)
-	}
-	if err := manager.InitializeExtension("manager-ext", map[string]interface{}{"quality": "hires"}); err != nil {
-		t.Fatalf("InitializeExtension: %v", err)
-	}
-	action, err := manager.InvokeAction("manager-ext", "doAction")
-	if err != nil || action["success"] != true || action["message"] != "done" {
-		t.Fatalf("InvokeAction = %#v/%v", action, err)
-	}
-	if err := manager.CleanupExtension("manager-ext"); err != nil {
-		t.Fatalf("CleanupExtension: %v", err)
-	}
-	if err := manager.SetExtensionEnabled("manager-ext", false); err != nil {
-		t.Fatalf("disable extension: %v", err)
-	}
-	if ext.VM != nil || ext.initialized {
-		t.Fatalf("expected VM teardown, got %#v", ext)
-	}
-	if _, err := manager.InvokeAction("manager-ext", "doAction"); err == nil {
-		t.Fatal("expected disabled action error")
-	}
-
-	upgradeJSON, err := manager.CheckExtensionUpgradeJSON(pkgV2)
-	if err != nil || !strings.Contains(upgradeJSON, `"can_upgrade":true`) {
-		t.Fatalf("CheckExtensionUpgradeJSON = %q/%v", upgradeJSON, err)
-	}
-	upgraded, err := manager.UpgradeExtension(pkgV2)
-	if err != nil {
-		t.Fatalf("UpgradeExtension: %v", err)
-	}
-	if upgraded.Manifest.Version != "1.1.0" {
-		t.Fatalf("upgraded = %#v", upgraded.Manifest)
-	}
-	if _, err := manager.UpgradeExtension(pkgV1); err == nil {
-		t.Fatal("expected downgrade error")
-	}
-	if err := manager.RemoveExtension("manager-ext"); err != nil {
-		t.Fatalf("RemoveExtension: %v", err)
-	}
-	if _, err := manager.GetExtension("manager-ext"); err == nil {
-		t.Fatal("expected removed extension missing")
-	}
-
-	dirExt := filepath.Join(extensionsDir, "dir-ext")
-	if err := os.MkdirAll(dirExt, 0755); err != nil {
-		t.Fatal(err)
-	}
-	manifest := `{"name":"dir-ext","displayName":"dir-ext","version":"1.0.0","description":"Directory extension","type":["metadata_provider"],"permissions":{}}`
-	if err := os.WriteFile(filepath.Join(dirExt, "manifest.json"), []byte(manifest), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(dirExt, "index.js"), []byte(`registerExtension({searchTracks:function(){return {tracks:[], total:0};}});`), 0600); err != nil {
-		t.Fatal(err)
-	}
-	loaded, loadErrs := manager.LoadExtensionsFromDirectory(extensionsDir)
-	if len(loadErrs) != 0 || len(loaded) != 1 || loaded[0] != "dir-ext" {
-		t.Fatalf("LoadExtensionsFromDirectory = %#v/%#v", loaded, loadErrs)
-	}
-	manager.UnloadAllExtensions()
-	if len(manager.GetAllExtensions()) != 0 {
-		t.Fatal("expected all extensions unloaded")
-	}
-}

go_backend/extension_manifest.go

@@ -25,10 +25,9 @@ const (
 )
 
 type ExtensionPermissions struct {
-	Network   []string `json:"network"`
-	Storage   bool     `json:"storage"`
-	File      bool     `json:"file"`
-	AllowHTTP bool     `json:"allowHttp,omitempty"`
+	Network []string `json:"network"`
+	Storage bool     `json:"storage"`
+	File    bool     `json:"file"`
 }
 
 type ExtensionSetting struct {
@@ -102,21 +101,11 @@ type PostProcessingConfig struct {
 	Hooks   []PostProcessingHook `json:"hooks,omitempty"`
 }
 
-type ExtensionHealthCheck struct {
-	ID              string `json:"id"`
-	Label           string `json:"label,omitempty"`
-	URL             string `json:"url"`
-	Method          string `json:"method,omitempty"`
-	ServiceKey      string `json:"serviceKey,omitempty"`
-	TimeoutMs       int    `json:"timeoutMs,omitempty"`
-	CacheTTLSeconds int    `json:"cacheTtlSeconds,omitempty"`
-	Required        bool   `json:"required,omitempty"`
-}
-
 type ExtensionManifest struct {
 	Name                   string                 `json:"name"`
 	DisplayName            string                 `json:"displayName"`
 	Version                string                 `json:"version"`
+	Author                 string                 `json:"author"`
 	Description            string                 `json:"description"`
 	Homepage               string                 `json:"homepage,omitempty"`
 	Icon                   string                 `json:"icon,omitempty"`
@@ -126,14 +115,11 @@ type ExtensionManifest struct {
 	QualityOptions         []QualityOption        `json:"qualityOptions,omitempty"`
 	MinAppVersion          string                 `json:"minAppVersion,omitempty"`
 	SkipMetadataEnrichment bool                   `json:"skipMetadataEnrichment,omitempty"`
-	SkipLyrics             bool                   `json:"skipLyrics,omitempty"`
-	StopProviderFallback   bool                   `json:"stopProviderFallback,omitempty"`
 	SkipBuiltInFallback    bool                   `json:"skipBuiltInFallback,omitempty"`
 	SearchBehavior         *SearchBehaviorConfig  `json:"searchBehavior,omitempty"`
 	URLHandler             *URLHandlerConfig      `json:"urlHandler,omitempty"`
 	TrackMatching          *TrackMatchingConfig   `json:"trackMatching,omitempty"`
 	PostProcessing         *PostProcessingConfig  `json:"postProcessing,omitempty"`
-	ServiceHealth          []ExtensionHealthCheck `json:"serviceHealth,omitempty"`
 	Capabilities           map[string]interface{} `json:"capabilities,omitempty"`
 }
 
@@ -168,6 +154,10 @@ func (m *ExtensionManifest) Validate() error {
 		return &ManifestValidationError{Field: "version", Message: "version is required"}
 	}
 
+	if strings.TrimSpace(m.Author) == "" {
+		return &ManifestValidationError{Field: "author", Message: "author is required"}
+	}
+
 	if strings.TrimSpace(m.Description) == "" {
 		return &ManifestValidationError{Field: "description", Message: "description is required"}
 	}
@@ -216,28 +206,6 @@ func (m *ExtensionManifest) Validate() error {
 		}
 	}
 
-	for i, check := range m.ServiceHealth {
-		if strings.TrimSpace(check.ID) == "" {
-			return &ManifestValidationError{
-				Field:   fmt.Sprintf("serviceHealth[%d].id", i),
-				Message: "health check id is required",
-			}
-		}
-		if strings.TrimSpace(check.URL) == "" {
-			return &ManifestValidationError{
-				Field:   fmt.Sprintf("serviceHealth[%d].url", i),
-				Message: "health check url is required",
-			}
-		}
-		method := strings.ToUpper(strings.TrimSpace(check.Method))
-		if method != "" && method != "GET" && method != "HEAD" {
-			return &ManifestValidationError{
-				Field:   fmt.Sprintf("serviceHealth[%d].method", i),
-				Message: "health check method must be GET or HEAD",
-			}
-		}
-	}
-
 	return nil
 }
 
@@ -262,13 +230,6 @@ func (m *ExtensionManifest) IsLyricsProvider() bool {
 	return m.HasType(ExtensionTypeLyricsProvider)
 }
 
-func (m *ExtensionManifest) StopsProviderFallback() bool {
-	if m == nil {
-		return false
-	}
-	return m.StopProviderFallback || m.SkipBuiltInFallback
-}
-
 func (m *ExtensionManifest) IsDomainAllowed(domain string) bool {
 	domain = strings.ToLower(strings.TrimSpace(domain))
 	for _, allowed := range m.Permissions.Network {

go_backend/extension_perf.go

@@ -1,119 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"time"
-
-	"github.com/dop251/goja"
-)
-
-type extensionCallPerf struct {
-	extensionID  string
-	operation    string
-	startedAt    time.Time
-	initMs       float64
-	jsMs         float64
-	parseMs      float64
-	items        int
-	payloadBytes int
-}
-
-func newExtensionCallPerf(extensionID, operation string) *extensionCallPerf {
-	if !GetLogBuffer().IsLoggingEnabled() {
-		return nil
-	}
-	return &extensionCallPerf{
-		extensionID: extensionID,
-		operation:   operation,
-		startedAt:   time.Now(),
-	}
-}
-
-func extensionDurationMs(duration time.Duration) float64 {
-	return float64(duration.Microseconds()) / 1000.0
-}
-
-func (p *extensionCallPerf) recordInit(duration time.Duration) {
-	if p == nil {
-		return
-	}
-	p.initMs += extensionDurationMs(duration)
-}
-
-func (p *extensionCallPerf) recordJS(duration time.Duration) {
-	if p == nil {
-		return
-	}
-	p.jsMs += extensionDurationMs(duration)
-}
-
-func (p *extensionCallPerf) recordParse(duration time.Duration) {
-	if p == nil {
-		return
-	}
-	p.parseMs += extensionDurationMs(duration)
-}
-
-func (p *extensionCallPerf) recordPayload(value goja.Value) {
-	if p == nil || gojaValueIsEmpty(value) {
-		return
-	}
-	if payload, err := json.Marshal(value); err == nil {
-		p.payloadBytes = len(payload)
-	}
-}
-
-func (p *extensionCallPerf) setPayloadBytes(payloadBytes int) {
-	if p == nil {
-		return
-	}
-	p.payloadBytes = payloadBytes
-}
-
-func (p *extensionCallPerf) setItems(items int) {
-	if p == nil {
-		return
-	}
-	p.items = items
-}
-
-func (p *extensionCallPerf) finish() {
-	if p == nil {
-		return
-	}
-	LogDebug(
-		"ExtensionPerf",
-		"extension=%s op=%s totalMs=%.1f initMs=%.1f jsMs=%.1f parseMs=%.1f items=%d payloadBytes=%d",
-		p.extensionID,
-		p.operation,
-		extensionDurationMs(time.Since(p.startedAt)),
-		p.initMs,
-		p.jsMs,
-		p.parseMs,
-		p.items,
-		p.payloadBytes,
-	)
-}
-
-func countExtensionTopLevelItems(vm *goja.Runtime, value goja.Value) int {
-	if gojaValueIsEmpty(value) {
-		return 0
-	}
-
-	if length, err := gojaArrayLength(value, vm); err == nil && length > 0 {
-		return length
-	}
-
-	obj := value.ToObject(vm)
-	for _, key := range []string{"items", "tracks", "sections", "albums", "artists", "playlists", "results"} {
-		child := obj.Get(key)
-		if gojaValueIsEmpty(child) {
-			continue
-		}
-		if length, err := gojaArrayLength(child, vm); err == nil && length > 0 {
-			return length
-		}
-	}
-
-	return 1
-}

go_backend/extension_provider_supplement_test.go

@@ -1,164 +0,0 @@
-package gobackend
-
-import (
-	"path/filepath"
-	"testing"
-)
-
-func TestExtensionProviderWrapperFullSurface(t *testing.T) {
-	ext := newTestLoadedExtension(t, ExtensionTypeMetadataProvider, ExtensionTypeDownloadProvider, ExtensionTypeLyricsProvider)
-	provider := newExtensionProviderWrapper(ext)
-
-	search, err := provider.SearchTracks("query", 5)
-	if err != nil {
-		t.Fatalf("SearchTracks: %v", err)
-	}
-	if search.Total != 1 || search.Tracks[0].ProviderID != ext.ID || search.Tracks[0].ExternalLinks["tidal"] == "" {
-		t.Fatalf("search = %#v", search)
-	}
-
-	track, err := provider.GetTrack("track-1")
-	if err != nil {
-		t.Fatalf("GetTrack: %v", err)
-	}
-	if track.Name != "Track track-1" || track.ProviderID != ext.ID || track.AudioQuality == "" {
-		t.Fatalf("track = %#v", track)
-	}
-
-	album, err := provider.GetAlbum("album-1")
-	if err != nil {
-		t.Fatalf("GetAlbum: %v", err)
-	}
-	if album.ProviderID != ext.ID || len(album.Tracks) != 1 || album.Tracks[0].ProviderID != ext.ID {
-		t.Fatalf("album = %#v", album)
-	}
-
-	playlist, err := provider.GetPlaylist("playlist-1")
-	if err != nil {
-		t.Fatalf("GetPlaylist: %v", err)
-	}
-	if playlist.Name != "Playlist playlist-1" || playlist.ProviderID != ext.ID {
-		t.Fatalf("playlist = %#v", playlist)
-	}
-
-	artist, err := provider.GetArtist("artist-1")
-	if err != nil {
-		t.Fatalf("GetArtist: %v", err)
-	}
-	if artist.ProviderID != ext.ID || len(artist.Releases) != 1 || artist.Releases[0].ProviderID != ext.ID {
-		t.Fatalf("artist = %#v", artist)
-	}
-
-	enriched, err := provider.EnrichTrack(&ExtTrackMetadata{ID: "track-1", Name: "Old", ProviderID: ext.ID})
-	if err != nil {
-		t.Fatalf("EnrichTrack: %v", err)
-	}
-	if enriched.Name != "Enriched" || enriched.ProviderID != ext.ID {
-		t.Fatalf("enriched = %#v", enriched)
-	}
-
-	availability, err := provider.CheckAvailability("ISRC", "Song", "Artist", "spotify:1", "dz", "tidal", "qobuz")
-	if err != nil {
-		t.Fatalf("CheckAvailability: %v", err)
-	}
-	if !availability.Available || availability.TrackID != "download-track" || !availability.SkipFallback {
-		t.Fatalf("availability = %#v", availability)
-	}
-
-	downloadURL, err := provider.GetDownloadURL("track-1", "LOSSLESS")
-	if err != nil {
-		t.Fatalf("GetDownloadURL: %v", err)
-	}
-	if downloadURL.Format != "flac" || downloadURL.BitDepth != 24 || downloadURL.SampleRate != 96000 {
-		t.Fatalf("download URL = %#v", downloadURL)
-	}
-
-	progress := []int{}
-	download, err := provider.Download("track-1", "LOSSLESS", filepath.Join(t.TempDir(), "song.flac"), "", func(percent int) {
-		progress = append(progress, percent)
-	})
-	if err != nil {
-		t.Fatalf("Download: %v", err)
-	}
-	if !download.Success || download.Decryption == nil || download.DecryptionKey != "001122" || len(progress) != 1 || progress[0] != 100 {
-		t.Fatalf("download = %#v progress=%v", download, progress)
-	}
-
-	lyrics, err := provider.FetchLyrics("Song", "Artist", "Album", 180)
-	if err != nil {
-		t.Fatalf("GetLyrics: %v", err)
-	}
-	if lyrics.Provider != ext.ID || len(lyrics.Lines) != 1 || lyrics.Lines[0].Words != "Hello" {
-		t.Fatalf("lyrics = %#v", lyrics)
-	}
-
-	urlResult, err := provider.HandleURL("https://example.test/track/1")
-	if err != nil {
-		t.Fatalf("HandleURL: %v", err)
-	}
-	if urlResult.Track == nil || urlResult.Track.Name == "" || len(urlResult.Tracks) != 1 || urlResult.Album == nil || urlResult.Artist == nil {
-		t.Fatalf("url result = %#v", urlResult)
-	}
-
-	match, err := provider.MatchTrack(
-		map[string]interface{}{"name": "Song", "artists": "Artist"},
-		[]map[string]interface{}{{"id": "download-track", "name": "Song"}},
-	)
-	if err != nil {
-		t.Fatalf("MatchTrack: %v", err)
-	}
-	if !match.Matched || match.TrackID != "download-track" {
-		t.Fatalf("match = %#v", match)
-	}
-
-	post, err := provider.PostProcess(filepath.Join(t.TempDir(), "song.flac"), map[string]interface{}{"title": "Song"}, "hook")
-	if err != nil {
-		t.Fatalf("PostProcess: %v", err)
-	}
-	if !post.Success || post.BitDepth != 24 || post.SampleRate != 96000 {
-		t.Fatalf("post = %#v", post)
-	}
-}
-
-func TestExtensionProviderAndManagerSelectionHelpers(t *testing.T) {
-	manifest := &ExtensionManifest{Capabilities: map[string]interface{}{
-		"replacesBuiltInProviders": []interface{}{" Deezer ", 7, ""},
-	}}
-	if values := manifestCapabilityStringList(manifest, "replacesBuiltInProviders"); len(values) != 1 || values[0] != "deezer" {
-		t.Fatalf("capability list = %#v", values)
-	}
-	if !extensionReplacesBuiltInProvider(&loadedExtension{Manifest: manifest}, "deezer") || extensionReplacesBuiltInProvider(nil, "deezer") {
-		t.Fatal("extension replacement mismatch")
-	}
-	if trimKnownProviderPrefix("Deezer:101", "deezer") != "101" || trimKnownProviderPrefix("101", "deezer") != "101" {
-		t.Fatal("trimKnownProviderPrefix mismatch")
-	}
-	if metadataTrackDedupKey(ExtTrackMetadata{ISRC: "usrc"}) != "isrc:USRC" ||
-		metadataTrackDedupKey(ExtTrackMetadata{SpotifyID: "sp"}) != "spotify:sp" ||
-		metadataTrackDedupKey(ExtTrackMetadata{ProviderID: "p", ID: "1"}) != "p:1" {
-		t.Fatal("metadata dedup key mismatch")
-	}
-
-	manager := &extensionManager{extensions: map[string]*loadedExtension{}}
-	downloadExt := newTestLoadedExtension(t, ExtensionTypeDownloadProvider, ExtensionTypeMetadataProvider)
-	manager.extensions[downloadExt.ID] = downloadExt
-	if providers := manager.GetDownloadProviders(); len(providers) != 1 {
-		t.Fatalf("download providers = %#v", providers)
-	}
-	SetProviderPriority([]string{"deezer", "coverage-ext", "coverage-ext", " "})
-	if priority := GetProviderPriority(); len(priority) != 1 || priority[0] != "coverage-ext" {
-		t.Fatalf("provider priority = %#v", priority)
-	}
-	SetExtensionFallbackProviderIDs([]string{"a", "a", " ", "b"})
-	if ids := GetExtensionFallbackProviderIDs(); len(ids) != 2 || !isExtensionFallbackAllowed("a") || isExtensionFallbackAllowed("z") {
-		t.Fatalf("fallback ids = %#v", ids)
-	}
-	SetExtensionFallbackProviderIDs(nil)
-	if !isExtensionFallbackAllowed("z") {
-		t.Fatal("nil fallback list should allow all")
-	}
-	SetMetadataProviderPriority([]string{"spotify", "deezer", "coverage-ext", "coverage-ext"})
-	if priority := GetMetadataProviderPriority(); len(priority) != 1 || priority[0] != "coverage-ext" {
-		t.Fatalf("metadata priority = %#v", priority)
-	}
-}

go_backend/extension_providers_test.go

@@ -1,87 +1,14 @@
 package gobackend
 
-import (
-	"context"
-	"crypto/tls"
-	"errors"
-	"fmt"
-	"net"
-	"net/http"
-	"net/http/httptest"
-	"os"
-	"path/filepath"
-	"sync"
-	"testing"
-	"time"
+import "testing"
 
-	"github.com/dop251/goja"
-)
-
-func TestSetMetadataProviderPriorityStripsRetiredBuiltIns(t *testing.T) {
+func TestSetMetadataProviderPriorityAddsBuiltIns(t *testing.T) {
 	original := GetMetadataProviderPriority()
 	defer SetMetadataProviderPriority(original)
 
-	SetMetadataProviderPriority([]string{"qobuz"})
+	SetMetadataProviderPriority([]string{"tidal"})
 	got := GetMetadataProviderPriority()
-	if len(got) != 0 {
-		t.Fatalf("expected retired built-in qobuz to be stripped, got %v", got)
-	}
-}
-
-func TestSetExtensionFallbackProviderIDsDedupesExtensions(t *testing.T) {
-	original := GetExtensionFallbackProviderIDs()
-	defer SetExtensionFallbackProviderIDs(original)
-
-	SetExtensionFallbackProviderIDs([]string{"ext-a", "ext-a", " ext-b "})
-
-	got := GetExtensionFallbackProviderIDs()
-	want := []string{"ext-a", "ext-b"}
-	if len(got) != len(want) {
-		t.Fatalf("unexpected fallback provider length: got %v want %v", got, want)
-	}
-	for i := range want {
-		if got[i] != want[i] {
-			t.Fatalf("unexpected fallback provider at %d: got %v want %v", i, got, want)
-		}
-	}
-}
-
-func TestIsExtensionFallbackAllowedDefaultsToAllExtensions(t *testing.T) {
-	original := GetExtensionFallbackProviderIDs()
-	defer SetExtensionFallbackProviderIDs(original)
-
-	SetExtensionFallbackProviderIDs(nil)
-
-	if !isExtensionFallbackAllowed("custom-ext") {
-		t.Fatal("expected custom extension to be allowed when no fallback allowlist is configured")
-	}
-}
-
-func TestIsExtensionFallbackAllowedRespectsAllowlist(t *testing.T) {
-	original := GetExtensionFallbackProviderIDs()
-	defer SetExtensionFallbackProviderIDs(original)
-
-	SetExtensionFallbackProviderIDs([]string{"allowed-ext"})
-
-	if !isExtensionFallbackAllowed("allowed-ext") {
-		t.Fatal("expected explicitly allowed extension to be permitted")
-	}
-	if isExtensionFallbackAllowed("blocked-ext") {
-		t.Fatal("expected extension outside allowlist to be blocked")
-	}
-	if isExtensionFallbackAllowed("deezer") {
-		t.Fatal("expected retired Deezer downloader to respect extension fallback allowlist")
-	}
-}
-
-func TestSetProviderPriorityRemovesRetiredDeezerDownloader(t *testing.T) {
-	original := GetProviderPriority()
-	defer SetProviderPriority(original)
-
-	SetProviderPriority([]string{"deezer", "qobuz", "custom-ext"})
-
-	got := GetProviderPriority()
-	want := []string{"custom-ext"}
+	want := []string{"tidal", "deezer", "qobuz"}
 	if len(got) != len(want) {
 		t.Fatalf("unexpected priority length: got %v want %v", got, want)
 	}
@@ -92,538 +19,50 @@ func TestSetProviderPriorityRemovesRetiredDeezerDownloader(t *testing.T) {
 	}
 }
 
-func TestNormalizeDownloadDecryptionInfoPromotesLegacyKey(t *testing.T) {
-	normalized := normalizeDownloadDecryptionInfo(nil, " 001122 ")
-	if normalized == nil {
-		t.Fatal("expected legacy decryption key to produce normalized descriptor")
-	}
-	if normalized.Strategy != genericFFmpegMOVDecryptionStrategy {
-		t.Fatalf("strategy = %q", normalized.Strategy)
-	}
-	if normalized.Key != "001122" {
-		t.Fatalf("key = %q", normalized.Key)
-	}
-	if normalized.InputFormat != "mov" {
-		t.Fatalf("input format = %q", normalized.InputFormat)
-	}
-}
-
-func TestNormalizeDownloadDecryptionInfoCanonicalizesMovAliases(t *testing.T) {
-	normalized := normalizeDownloadDecryptionInfo(&DownloadDecryptionInfo{
-		Strategy:    "mp4_decryption_key",
-		Key:         "abcd",
-		InputFormat: "",
-	}, "")
-	if normalized == nil {
-		t.Fatal("expected descriptor to remain available")
-	}
-	if normalized.Strategy != genericFFmpegMOVDecryptionStrategy {
-		t.Fatalf("strategy = %q", normalized.Strategy)
-	}
-	if normalized.InputFormat != "mov" {
-		t.Fatalf("input format = %q", normalized.InputFormat)
-	}
-}
-
-func TestExtensionDownloadUsesIsolatedRuntimeForConcurrentCalls(t *testing.T) {
-	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		time.Sleep(500 * time.Millisecond)
-		_, _ = w.Write([]byte("ok"))
-	}))
-	defer server.Close()
-	setPrivateIPCache("download.test", false, time.Minute)
-
-	originalTransport := sharedTransport
-	testTransport := &http.Transport{
-		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-			return (&net.Dialer{}).DialContext(ctx, network, server.Listener.Addr().String())
-		},
-		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
-	}
-	sharedTransport = testTransport
+func TestSearchTracksWithMetadataProvidersUsesPriorityAndDedupes(t *testing.T) {
+	originalPriority := GetMetadataProviderPriority()
+	originalSearch := searchBuiltInMetadataTracksFunc
 	defer func() {
-		testTransport.CloseIdleConnections()
-		sharedTransport = originalTransport
+		SetMetadataProviderPriority(originalPriority)
+		searchBuiltInMetadataTracksFunc = originalSearch
 	}()
 
-	extDir := t.TempDir()
-	if err := os.WriteFile(filepath.Join(extDir, "index.js"), []byte(`
-		registerExtension({
-			download: function(trackID, quality, outputPath, onProgress) {
-				var result = file.download('https://download.test/' + trackID, outputPath, {
-					onProgress: function(written, total) {
-						if (onProgress) onProgress(50);
-					}
-				});
-				if (!result || !result.success) {
-					return {
-						success: false,
-						error_message: result && result.error ? result.error : 'download failed',
-						error_type: 'download_error'
-					};
-				}
-				if (onProgress) onProgress(100);
-				return { success: true, file_path: result.path };
-			}
-		});
-	`), 0600); err != nil {
-		t.Fatalf("write extension index: %v", err)
-	}
+	SetMetadataProviderPriority([]string{"qobuz", "tidal", "deezer"})
 
-	outputDir := t.TempDir()
-	SetAllowedDownloadDirs([]string{outputDir})
-	defer SetAllowedDownloadDirs(nil)
-
-	ext := &loadedExtension{
-		ID: "concurrent-download",
-		Manifest: &ExtensionManifest{
-			Name:        "concurrent-download",
-			Description: "Concurrent download test",
-			Version:     "1.0.0",
-			Types:       []ExtensionType{ExtensionTypeDownloadProvider},
-			Permissions: ExtensionPermissions{
-				Network: []string{"download.test"},
-				File:    true,
-			},
-		},
-		Enabled:   true,
-		SourceDir: extDir,
-		DataDir:   t.TempDir(),
-	}
-	provider := newExtensionProviderWrapper(ext)
-
-	start := time.Now()
-	var wg sync.WaitGroup
-	errs := make(chan error, 2)
-	for i := 0; i < 2; i++ {
-		i := i
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-			result, err := provider.Download(
-				fmt.Sprintf("track-%d", i),
-				"LOSSLESS",
-				filepath.Join(outputDir, fmt.Sprintf("track-%d.flac", i)),
-				"",
-				nil,
-			)
-			if err != nil {
-				errs <- err
-				return
-			}
-			if result == nil || !result.Success {
-				errs <- fmt.Errorf("download failed: %#v", result)
-			}
-		}()
-	}
-	wg.Wait()
-	close(errs)
-	for err := range errs {
-		if err != nil {
-			t.Fatal(err)
+	var calls []string
+	searchBuiltInMetadataTracksFunc = func(providerID, query string, limit int) ([]ExtTrackMetadata, error) {
+		calls = append(calls, providerID)
+		switch providerID {
+		case "qobuz":
+			return []ExtTrackMetadata{
+				{ProviderID: "qobuz", SpotifyID: "qobuz:1", ISRC: "AAA111", Name: "First"},
+			}, nil
+		case "tidal":
+			return []ExtTrackMetadata{
+				{ProviderID: "tidal", SpotifyID: "tidal:2", ISRC: "AAA111", Name: "Duplicate"},
+				{ProviderID: "tidal", SpotifyID: "tidal:3", ISRC: "BBB222", Name: "Second"},
+			}, nil
+		case "deezer":
+			return []ExtTrackMetadata{
+				{ProviderID: "deezer", SpotifyID: "deezer:4", ISRC: "CCC333", Name: "Third"},
+			}, nil
+		default:
+			return nil, nil
 		}
 	}
 
-	if elapsed := time.Since(start); elapsed >= 850*time.Millisecond {
-		t.Fatalf("expected same-extension downloads to overlap, elapsed %s", elapsed)
-	}
-}
-
-func TestBuildOutputPathAddsExplicitOutputDirToAllowedDirs(t *testing.T) {
-	SetAllowedDownloadDirs(nil)
-
-	outputDir := t.TempDir()
-	outputPath := buildOutputPath(DownloadRequest{
-		TrackName:      "Song",
-		ArtistName:     "Artist",
-		OutputDir:      outputDir,
-		OutputExt:      ".flac",
-		FilenameFormat: "",
-	})
-
-	if !isPathInAllowedDirs(outputPath) {
-		t.Fatalf("expected output path %q to be allowed", outputPath)
-	}
-}
-
-func TestBuildOutputPathForExtensionAddsExplicitOutputPathDirToAllowedDirs(t *testing.T) {
-	SetAllowedDownloadDirs(nil)
-
-	outputDir := t.TempDir()
-	outputPath := filepath.Join(outputDir, "custom.flac")
-	ext := &loadedExtension{DataDir: t.TempDir()}
-
-	resolved := buildOutputPathForExtension(DownloadRequest{
-		OutputPath: outputPath,
-	}, ext)
-
-	if resolved != outputPath {
-		t.Fatalf("resolved output path = %q", resolved)
-	}
-	if !isPathInAllowedDirs(outputPath) {
-		t.Fatalf("expected output path %q to be allowed", outputPath)
-	}
-}
-
-func TestBuildOutputPathForExtensionUsesTempDirForFDOutput(t *testing.T) {
-	SetAllowedDownloadDirs(nil)
-
-	ext := &loadedExtension{DataDir: t.TempDir()}
-	resolved := buildOutputPathForExtension(DownloadRequest{
-		TrackName:  "Song",
-		ArtistName: "Artist",
-		OutputDir:  filepath.Join("Artist", "Album"),
-		OutputFD:   123,
-		OutputExt:  ".flac",
-	}, ext)
-
-	expectedBase := filepath.Join(ext.DataDir, "downloads")
-	if !isPathWithinBase(expectedBase, resolved) {
-		t.Fatalf("expected SAF extension output under %q, got %q", expectedBase, resolved)
-	}
-	if !isPathInAllowedDirs(resolved) {
-		t.Fatalf("expected resolved output path %q to be allowed", resolved)
-	}
-}
-
-func TestShouldStopProviderFallback(t *testing.T) {
-	if shouldStopProviderFallback(nil) {
-		t.Fatal("nil availability should not stop fallback")
-	}
-	if shouldStopProviderFallback(&ExtAvailabilityResult{Available: false}) {
-		t.Fatal("availability without skip_fallback should not stop fallback")
-	}
-	if !shouldStopProviderFallback(&ExtAvailabilityResult{Available: false, SkipFallback: true}) {
-		t.Fatal("skip_fallback availability should stop fallback")
-	}
-}
-
-func TestBuildExtensionFallbackStoppedResponsePrefersAvailabilityReason(t *testing.T) {
-	resp := buildExtensionFallbackStoppedResponse("soundcloud", &ExtAvailabilityResult{
-		Reason:       "direct SoundCloud track ID",
-		SkipFallback: true,
-	}, errors.New("ignored"))
-
-	if resp.Service != "soundcloud" {
-		t.Fatalf("service = %q", resp.Service)
-	}
-	if resp.Error != "Fallback stopped by soundcloud: direct SoundCloud track ID" {
-		t.Fatalf("unexpected error message: %q", resp.Error)
-	}
-	if resp.ErrorType != "extension_error" {
-		t.Fatalf("error type = %q", resp.ErrorType)
-	}
-}
-
-func TestBuildExtensionFallbackStoppedResponseFallsBackToError(t *testing.T) {
-	resp := buildExtensionFallbackStoppedResponse("soundcloud", &ExtAvailabilityResult{
-		SkipFallback: true,
-	}, errors.New("lookup failed"))
-
-	if resp.Error != "Fallback stopped by soundcloud: lookup failed" {
-		t.Fatalf("unexpected error message: %q", resp.Error)
-	}
-}
-
-func TestShouldAbortCancelledFallbackWithCancelledError(t *testing.T) {
-	if !shouldAbortCancelledFallback("", ErrDownloadCancelled) {
-		t.Fatal("expected cancelled error to abort fallback")
-	}
-}
-
-func TestShouldAbortCancelledFallbackWithCancelledItemState(t *testing.T) {
-	const itemID = "cancelled-item"
-	initDownloadCancel(itemID)
-	defer clearDownloadCancel(itemID)
-
-	cancelDownload(itemID)
-
-	if !shouldAbortCancelledFallback(itemID, errors.New("generic failure")) {
-		t.Fatal("expected cancelled item state to abort fallback even for generic errors")
-	}
-}
-
-func TestCanEmbedGenreLabelRequiresExistingAbsoluteLocalFile(t *testing.T) {
-	tempFile := filepath.Join(t.TempDir(), "track.flac")
-	if err := os.WriteFile(tempFile, []byte("fLaC"), 0644); err != nil {
-		t.Fatalf("failed to create temp file: %v", err)
-	}
-	tempM4A := filepath.Join(t.TempDir(), "track.m4a")
-	if err := os.WriteFile(tempM4A, []byte("not-flac"), 0644); err != nil {
-		t.Fatalf("failed to create temp m4a file: %v", err)
-	}
-
-	if canEmbedGenreLabel("relative.flac") {
-		t.Fatal("expected relative path to be rejected")
-	}
-	if canEmbedGenreLabel("content://example") {
-		t.Fatal("expected content URI to be rejected")
-	}
-	if canEmbedGenreLabel(filepath.Join(t.TempDir(), "missing.flac")) {
-		t.Fatal("expected missing file to be rejected")
-	}
-	if canEmbedGenreLabel(tempM4A) {
-		t.Fatalf("expected non-FLAC file %q to be rejected", tempM4A)
-	}
-	if !canEmbedGenreLabel(tempFile) {
-		t.Fatalf("expected existing absolute file %q to be accepted", tempFile)
-	}
-}
-
-func TestSearchTracksWithMetadataProvidersIgnoresRetiredBuiltIns(t *testing.T) {
-	originalPriority := GetMetadataProviderPriority()
-	defer func() {
-		SetMetadataProviderPriority(originalPriority)
-	}()
-
-	SetMetadataProviderPriority([]string{"qobuz"})
-
-	manager := getExtensionManager()
+	manager := GetExtensionManager()
 	tracks, err := manager.SearchTracksWithMetadataProviders("query", 3, false)
 	if err != nil {
 		t.Fatalf("SearchTracksWithMetadataProviders returned error: %v", err)
 	}
-	if len(tracks) != 0 {
-		t.Fatalf("expected no tracks from retired built-in provider, got %+v", tracks)
-	}
-}
-
-func TestParseExtensionSearchResultAcceptsObjectAndArrayShapes(t *testing.T) {
-	vm := goja.New()
-	value, err := vm.RunString(`({
-		tracks: [{
-			id: "track-1",
-			name: "Song",
-			artists: "Artist",
-			album_name: "Album",
-			duration_ms: 123000,
-			cover_url: "https://img.test/cover.jpg",
-			external_links: { spotify: "spotify:track:1" },
-			audio_quality: "LOSSLESS"
-		}],
-		total: 9
-	})`)
-	if err != nil {
-		t.Fatalf("build object search result: %v", err)
-	}
-
-	result, err := parseExtensionSearchResult(vm, value)
-	if err != nil {
-		t.Fatalf("parse object search result: %v", err)
-	}
-	if result.Total != 9 || len(result.Tracks) != 1 {
-		t.Fatalf("unexpected object result: %+v", result)
-	}
-	track := result.Tracks[0]
-	if track.ID != "track-1" ||
-		track.AlbumName != "Album" ||
-		track.DurationMS != 123000 ||
-		track.CoverURL != "https://img.test/cover.jpg" ||
-		track.ExternalLinks["spotify"] != "spotify:track:1" ||
-		track.AudioQuality != "LOSSLESS" {
-		t.Fatalf("unexpected parsed track: %+v", track)
-	}
-
-	arrayValue, err := vm.RunString(`[
-		{id: "track-2", name: "Other Song", artists: "Other Artist", albumName: "Other Album", durationMs: 456000}
-	]`)
-	if err != nil {
-		t.Fatalf("build array search result: %v", err)
-	}
-
-	arrayResult, err := parseExtensionSearchResult(vm, arrayValue)
-	if err != nil {
-		t.Fatalf("parse array search result: %v", err)
-	}
-	if arrayResult.Total != 1 ||
-		len(arrayResult.Tracks) != 1 ||
-		arrayResult.Tracks[0].AlbumName != "Other Album" ||
-		arrayResult.Tracks[0].DurationMS != 456000 {
-		t.Fatalf("unexpected array result: %+v", arrayResult)
-	}
-}
-
-func TestParseExtensionMetadataAndDownloadResults(t *testing.T) {
-	vm := goja.New()
-	value, err := vm.RunString(`({
-		id: "album-1",
-		name: "Album",
-		artists: "Artist",
-		artistId: "artist-1",
-		coverUrl: "https://img.test/album.jpg",
-		releaseDate: "2024-02-03",
-		totalTracks: 2,
-		albumType: "album",
-		tracks: [
-			{id: "track-1", name: "Song 1", artists: "Artist", durationMs: 180000},
-			{id: "track-2", name: "Song 2", artists: "Artist", duration_ms: 181000}
-		]
-	})`)
-	if err != nil {
-		t.Fatalf("build album value: %v", err)
-	}
-
-	album, err := parseExtensionAlbumValue(vm, value)
-	if err != nil {
-		t.Fatalf("parse album: %v", err)
-	}
-	if album.ID != "album-1" ||
-		album.ArtistID != "artist-1" ||
-		album.CoverURL != "https://img.test/album.jpg" ||
-		album.TotalTracks != 2 ||
-		len(album.Tracks) != 2 ||
-		album.Tracks[0].DurationMS != 180000 ||
-		album.Tracks[1].DurationMS != 181000 {
-		t.Fatalf("unexpected album: %+v", album)
-	}
-
-	artistValue, err := vm.RunString(`({
-		id: "artist-1",
-		name: "Artist",
-		imageUrl: "https://img.test/artist.jpg",
-		headerImage: "https://img.test/header.jpg",
-		listeners: 1234,
-		albums: [{id: "album-1", name: "Album", tracks: [{id: "track-1", name: "Song"}]}],
-		releases: [{id: "single-1", name: "Single"}],
-		topTracks: [{id: "top-1", name: "Top Song"}]
-	})`)
-	if err != nil {
-		t.Fatalf("build artist value: %v", err)
-	}
-
-	artist, err := parseExtensionArtistValue(vm, artistValue)
-	if err != nil {
-		t.Fatalf("parse artist: %v", err)
-	}
-	if artist.ID != "artist-1" ||
-		artist.ImageURL != "https://img.test/artist.jpg" ||
-		artist.HeaderImage != "https://img.test/header.jpg" ||
-		artist.Listeners != 1234 ||
-		len(artist.Albums) != 1 ||
-		len(artist.Albums[0].Tracks) != 1 ||
-		len(artist.Releases) != 1 ||
-		len(artist.TopTracks) != 1 {
-		t.Fatalf("unexpected artist: %+v", artist)
-	}
-
-	downloadValue, err := vm.RunString(`({
-		success: true,
-		filePath: "/tmp/song.flac",
-		alreadyExists: true,
-		bitDepth: 24,
-		sampleRate: 96000,
-		title: "Song",
-		albumArtist: "Album Artist",
-		lyricsLrc: "[00:00.00]Line",
-		decryptionKey: "001122",
-		decryption: {
-			strategy: "mp4_decryption_key",
-			key: "001122",
-			inputFormat: "m4a",
-			options: { map: "0:a" }
-		}
-	})`)
-	if err != nil {
-		t.Fatalf("build download value: %v", err)
-	}
-
-	download := parseExtensionDownloadResultValue(vm, downloadValue)
-	if !download.Success ||
-		download.FilePath != "/tmp/song.flac" ||
-		!download.AlreadyExists ||
-		download.BitDepth != 24 ||
-		download.SampleRate != 96000 ||
-		download.AlbumArtist != "Album Artist" ||
-		download.LyricsLRC != "[00:00.00]Line" ||
-		download.Decryption == nil ||
-		download.Decryption.InputFormat != "m4a" ||
-		download.Decryption.Options["map"] != "0:a" {
-		t.Fatalf("unexpected download result: %+v", download)
-	}
-
-	availabilityValue, err := vm.RunString(`({ available: true, trackId: "track-1", skipFallback: true, reason: "direct" })`)
-	if err != nil {
-		t.Fatalf("build availability value: %v", err)
-	}
-	availability := parseExtensionAvailabilityValue(vm, availabilityValue)
-	if !availability.Available || availability.TrackID != "track-1" || !availability.SkipFallback || availability.Reason != "direct" {
-		t.Fatalf("unexpected availability: %+v", availability)
-	}
-}
-
-func TestParseExtensionURLHandleResult(t *testing.T) {
-	vm := goja.New()
-	value, err := vm.RunString(`({
-		type: "album",
-		name: "Shared Album",
-		coverUrl: "https://img.test/shared.jpg",
-		track: { id: "track-1", name: "Song" },
-		tracks: [{ id: "track-2", name: "Song 2" }],
-		album: { id: "album-1", name: "Album", tracks: [{ id: "track-3", name: "Song 3" }] },
-		artist: { id: "artist-1", name: "Artist", topTracks: [{ id: "track-4", name: "Song 4" }] }
-	})`)
-	if err != nil {
-		t.Fatalf("build URL handle value: %v", err)
-	}
-
-	result, err := parseExtensionURLHandleValue(vm, value)
-	if err != nil {
-		t.Fatalf("parse URL handle: %v", err)
-	}
-	if result.Type != "album" ||
-		result.CoverURL != "https://img.test/shared.jpg" ||
-		result.Track == nil ||
-		result.Track.ID != "track-1" ||
-		len(result.Tracks) != 1 ||
-		result.Album == nil ||
-		len(result.Album.Tracks) != 1 ||
-		result.Artist == nil ||
-		len(result.Artist.TopTracks) != 1 {
-		t.Fatalf("unexpected URL handle result: %+v", result)
-	}
-}
-
-func TestParseExtensionAuxiliaryResults(t *testing.T) {
-	vm := goja.New()
-
-	matchValue, err := vm.RunString(`({ matched: true, trackId: "track-1", confidence: 0.92, reason: "isrc" })`)
-	if err != nil {
-		t.Fatalf("build match value: %v", err)
-	}
-	match := parseExtensionMatchTrackValue(vm, matchValue)
-	if !match.Matched || match.TrackID != "track-1" || match.Confidence != 0.92 || match.Reason != "isrc" {
-		t.Fatalf("unexpected match result: %+v", match)
-	}
-
-	postValue, err := vm.RunString(`({ success: true, newFilePath: "/tmp/new.flac", newFileUri: "content://new", bitDepth: 24, sampleRate: 96000 })`)
-	if err != nil {
-		t.Fatalf("build post-process value: %v", err)
-	}
-	post := parseExtensionPostProcessValue(vm, postValue)
-	if !post.Success || post.NewFilePath != "/tmp/new.flac" || post.NewFileURI != "content://new" || post.BitDepth != 24 || post.SampleRate != 96000 {
-		t.Fatalf("unexpected post-process result: %+v", post)
-	}
-
-	lyricsValue, err := vm.RunString(`({
-		syncType: "LINE_SYNCED",
-		instrumental: false,
-		plainLyrics: "Line",
-		provider: "Lyrics Provider",
-		lines: [{ startTimeMs: 1000, words: "Line", endTimeMs: 2000 }]
-	})`)
-	if err != nil {
-		t.Fatalf("build lyrics value: %v", err)
-	}
-	lyrics, err := parseExtensionLyricsValue(vm, lyricsValue)
-	if err != nil {
-		t.Fatalf("parse lyrics: %v", err)
-	}
-	if lyrics.SyncType != "LINE_SYNCED" ||
-		lyrics.PlainLyrics != "Line" ||
-		lyrics.Provider != "Lyrics Provider" ||
-		len(lyrics.Lines) != 1 ||
-		lyrics.Lines[0].StartTimeMs != 1000 ||
-		lyrics.Lines[0].EndTimeMs != 2000 {
-		t.Fatalf("unexpected lyrics result: %+v", lyrics)
+	if len(tracks) != 3 {
+		t.Fatalf("unexpected track count: got %d want 3", len(tracks))
+	}
+	if tracks[0].ProviderID != "qobuz" || tracks[1].ProviderID != "tidal" || tracks[2].ProviderID != "deezer" {
+		t.Fatalf("unexpected track provider order: %+v", tracks)
+	}
+	if len(calls) != 3 || calls[0] != "qobuz" || calls[1] != "tidal" || calls[2] != "deezer" {
+		t.Fatalf("unexpected provider call order: %v", calls)
 	}
 }

go_backend/extension_runtime.go

@@ -5,7 +5,6 @@ import (
 	"net"
 	"net/http"
 	"net/url"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -81,7 +80,7 @@ func SetExtensionTokens(extensionID string, accessToken, refreshToken string, ex
 	state.IsAuthenticated = accessToken != ""
 }
 
-type extensionRuntime struct {
+type ExtensionRuntime struct {
 	extensionID    string
 	manifest       *ExtensionManifest
 	settings       map[string]interface{}
@@ -94,9 +93,6 @@ type extensionRuntime struct {
 	activeDownloadMu     sync.RWMutex
 	activeDownloadItemID string
 
-	activeRequestMu sync.RWMutex
-	activeRequestID string
-
 	storageMu      sync.RWMutex
 	storageCache   map[string]interface{}
 	storageLoaded  bool
@@ -127,10 +123,10 @@ var (
 	privateIPCacheMu sync.RWMutex
 )
 
-func newExtensionRuntime(ext *loadedExtension) *extensionRuntime {
+func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 	jar, _ := newSimpleCookieJar()
 
-	runtime := &extensionRuntime{
+	runtime := &ExtensionRuntime{
 		extensionID:       ext.ID,
 		manifest:          ext.Manifest,
 		settings:          make(map[string]interface{}),
@@ -140,114 +136,31 @@ func newExtensionRuntime(ext *loadedExtension) *extensionRuntime {
 		storageFlushDelay: defaultStorageFlushDelay,
 	}
 
-	runtime.httpClient = newExtensionHTTPClient(ext, jar, extensionHTTPTimeout(ext, 30*time.Second))
+	runtime.httpClient = newExtensionHTTPClient(ext, jar, 30*time.Second)
 	runtime.downloadClient = newExtensionHTTPClient(ext, jar, DownloadTimeout)
 
 	return runtime
 }
 
-func extensionHTTPTimeout(ext *loadedExtension, fallback time.Duration) time.Duration {
-	if ext == nil || ext.Manifest == nil || ext.Manifest.Capabilities == nil {
-		return fallback
-	}
-
-	raw, ok := ext.Manifest.Capabilities["networkTimeoutSeconds"]
-	if !ok {
-		return fallback
-	}
-
-	seconds := parseExtensionTimeoutSeconds(raw)
-	if seconds <= 0 {
-		return fallback
-	}
-
-	if seconds < 5 {
-		seconds = 5
-	}
-	if seconds > 300 {
-		seconds = 300
-	}
-
-	return time.Duration(seconds) * time.Second
-}
-
-func parseExtensionTimeoutSeconds(raw interface{}) int {
-	switch v := raw.(type) {
-	case int:
-		return v
-	case int32:
-		return int(v)
-	case int64:
-		return int(v)
-	case float32:
-		return int(v)
-	case float64:
-		return int(v)
-	case string:
-		parsed, err := strconv.Atoi(strings.TrimSpace(v))
-		if err != nil {
-			return 0
-		}
-		return parsed
-	default:
-		return 0
-	}
-}
-
-func (r *extensionRuntime) setActiveDownloadItemID(itemID string) {
+func (r *ExtensionRuntime) setActiveDownloadItemID(itemID string) {
 	r.activeDownloadMu.Lock()
 	defer r.activeDownloadMu.Unlock()
 	r.activeDownloadItemID = strings.TrimSpace(itemID)
 }
 
-func (r *extensionRuntime) clearActiveDownloadItemID() {
+func (r *ExtensionRuntime) clearActiveDownloadItemID() {
 	r.activeDownloadMu.Lock()
 	defer r.activeDownloadMu.Unlock()
 	r.activeDownloadItemID = ""
 }
 
-func (r *extensionRuntime) getActiveDownloadItemID() string {
+func (r *ExtensionRuntime) getActiveDownloadItemID() string {
 	r.activeDownloadMu.RLock()
 	defer r.activeDownloadMu.RUnlock()
 	return r.activeDownloadItemID
 }
 
-func (r *extensionRuntime) setActiveRequestID(requestID string) {
-	r.activeRequestMu.Lock()
-	defer r.activeRequestMu.Unlock()
-	r.activeRequestID = strings.TrimSpace(requestID)
-}
-
-func (r *extensionRuntime) clearActiveRequestID() {
-	r.activeRequestMu.Lock()
-	defer r.activeRequestMu.Unlock()
-	r.activeRequestID = ""
-}
-
-func (r *extensionRuntime) getActiveRequestID() string {
-	r.activeRequestMu.RLock()
-	defer r.activeRequestMu.RUnlock()
-	return r.activeRequestID
-}
-
-func (r *extensionRuntime) bindDownloadCancelContext(req *http.Request) *http.Request {
-	if req == nil {
-		return nil
-	}
-
-	itemID := r.getActiveDownloadItemID()
-	if itemID == "" {
-		requestID := r.getActiveRequestID()
-		if requestID == "" {
-			return req
-		}
-		return req.WithContext(initExtensionRequestCancel(requestID))
-	}
-
-	return req.WithContext(initDownloadCancel(itemID))
-}
-
-func newExtensionHTTPClient(ext *loadedExtension, jar http.CookieJar, timeout time.Duration) *http.Client {
+func newExtensionHTTPClient(ext *LoadedExtension, jar http.CookieJar, timeout time.Duration) *http.Client {
 	// Extension sandbox enforces HTTPS-only domains. Do not apply global
 	// allow_http scheme downgrade here, because some extension APIs (e.g.
 	// spotify-web) will redirect http -> https and can end up in 301 loops.
@@ -258,8 +171,7 @@ func newExtensionHTTPClient(ext *loadedExtension, jar http.CookieJar, timeout ti
 		Jar:       jar,
 	}
 	client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
-		if req.URL.Scheme != "https" &&
-			!(req.URL.Scheme == "http" && ext.Manifest.Permissions.AllowHTTP) {
+		if req.URL.Scheme != "https" {
 			GoLog("[Extension:%s] Redirect blocked: non-https scheme '%s'\n", ext.ID, req.URL.Scheme)
 			return fmt.Errorf("redirect blocked: only https is allowed")
 		}
@@ -417,11 +329,11 @@ func (j *simpleCookieJar) Cookies(u *url.URL) []*http.Cookie {
 	return j.cookies[u.Host]
 }
 
-func (r *extensionRuntime) SetSettings(settings map[string]interface{}) {
+func (r *ExtensionRuntime) SetSettings(settings map[string]interface{}) {
 	r.settings = settings
 }
 
-func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
+func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	r.vm = vm
 
 	httpObj := vm.NewObject()
@@ -465,9 +377,7 @@ func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	fileObj.Set("exists", r.fileExists)
 	fileObj.Set("delete", r.fileDelete)
 	fileObj.Set("read", r.fileRead)
-	fileObj.Set("readBytes", r.fileReadBytes)
 	fileObj.Set("write", r.fileWrite)
-	fileObj.Set("writeBytes", r.fileWriteBytes)
 	fileObj.Set("copy", r.fileCopy)
 	fileObj.Set("move", r.fileMove)
 	fileObj.Set("getSize", r.fileGetSize)
@@ -497,16 +407,8 @@ func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	utilsObj.Set("stringifyJSON", r.stringifyJSON)
 	utilsObj.Set("encrypt", r.cryptoEncrypt)
 	utilsObj.Set("decrypt", r.cryptoDecrypt)
-	utilsObj.Set("encryptBlockCipher", r.encryptBlockCipher)
-	utilsObj.Set("decryptBlockCipher", r.decryptBlockCipher)
 	utilsObj.Set("generateKey", r.cryptoGenerateKey)
 	utilsObj.Set("randomUserAgent", r.randomUserAgent)
-	utilsObj.Set("appVersion", r.appVersion)
-	utilsObj.Set("appUserAgent", r.appUserAgent)
-	utilsObj.Set("sleep", r.sleep)
-	utilsObj.Set("isDownloadCancelled", r.isDownloadCancelled)
-	utilsObj.Set("isRequestCancelled", r.isRequestCancelled)
-	utilsObj.Set("setDownloadStatus", r.setDownloadStatus)
 	vm.Set("utils", utilsObj)
 
 	logObj := vm.NewObject()

go_backend/extension_runtime_auth.go

@@ -52,7 +52,7 @@ func summarizeURLForLog(urlStr string) string {
 	return fmt.Sprintf("%s://%s%s", parsed.Scheme, parsed.Host, parsed.Path)
 }
 
-func (r *extensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -99,7 +99,7 @@ func (r *extensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -111,7 +111,7 @@ func (r *extensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(state.AuthCode)
 }
 
-func (r *extensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -149,7 +149,7 @@ func (r *extensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *extensionRuntime) authClear(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authClear(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.Lock()
 	delete(extensionAuthState, r.extensionID)
 	extensionAuthStateMu.Unlock()
@@ -162,7 +162,7 @@ func (r *extensionRuntime) authClear(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *extensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -178,7 +178,7 @@ func (r *extensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Valu
 	return r.vm.ToValue(state.IsAuthenticated)
 }
 
-func (r *extensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -201,6 +201,7 @@ func (r *extensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(result)
 }
 
+// Length should be between 43-128 characters (RFC 7636)
 func generatePKCEVerifier(length int) (string, error) {
 	if length < 43 {
 		length = 43
@@ -225,10 +226,11 @@ func generatePKCEVerifier(length int) (string, error) {
 
 func generatePKCEChallenge(verifier string) string {
 	hash := sha256.Sum256([]byte(verifier))
+	// Base64url encode without padding (RFC 7636)
 	return base64.RawURLEncoding.EncodeToString(hash[:])
 }
 
-func (r *extensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	length := 64
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok && l >= 43 && l <= 128 {
@@ -265,7 +267,7 @@ func (r *extensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
 
@@ -281,7 +283,8 @@ func (r *extensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.Value {
+// config: { authUrl, clientId, redirectUri, scope, extraParams }
+func (r *ExtensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -385,7 +388,8 @@ func (r *extensionRuntime) authStartOAuthWithPKCE(call goja.FunctionCall) goja.V
 	})
 }
 
-func (r *extensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja.Value {
+// config: { tokenUrl, clientId, redirectUri, code, extraParams }
+func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -458,10 +462,9 @@ func (r *extensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 			"error":   err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")
 
 	resp, err := r.httpClient.Do(req)
 	if err != nil {

go_backend/extension_runtime_binary.go

@@ -1,360 +0,0 @@
-package gobackend
-
-import (
-	"crypto/aes"
-	"crypto/cipher"
-	"encoding/base64"
-	"encoding/hex"
-	"fmt"
-	"strings"
-
-	"github.com/dop251/goja"
-	//lint:ignore SA1019 Blowfish is required for legacy extension crypto compatibility.
-	"golang.org/x/crypto/blowfish"
-)
-
-type runtimeBlockCipherOptions struct {
-	Algorithm      string
-	Mode           string
-	Key            []byte
-	IV             []byte
-	InputEncoding  string
-	OutputEncoding string
-	Padding        string
-}
-
-func parseRuntimeOptionsArgument(call goja.FunctionCall, index int) map[string]interface{} {
-	if len(call.Arguments) <= index {
-		return nil
-	}
-
-	value := call.Arguments[index]
-	if goja.IsUndefined(value) || goja.IsNull(value) {
-		return nil
-	}
-
-	exported := value.Export()
-	if options, ok := exported.(map[string]interface{}); ok {
-		return options
-	}
-	return nil
-}
-
-func runtimeOptionString(options map[string]interface{}, key, defaultValue string) string {
-	if options == nil {
-		return defaultValue
-	}
-	raw, ok := options[key]
-	if !ok || raw == nil {
-		return defaultValue
-	}
-	switch value := raw.(type) {
-	case string:
-		if trimmed := strings.TrimSpace(value); trimmed != "" {
-			return trimmed
-		}
-	case []byte:
-		if len(value) > 0 {
-			return string(value)
-		}
-	}
-	return defaultValue
-}
-
-func runtimeOptionBool(options map[string]interface{}, key string, defaultValue bool) bool {
-	if options == nil {
-		return defaultValue
-	}
-	raw, ok := options[key]
-	if !ok || raw == nil {
-		return defaultValue
-	}
-	switch value := raw.(type) {
-	case bool:
-		return value
-	case int:
-		return value != 0
-	case int64:
-		return value != 0
-	case float64:
-		return value != 0
-	case string:
-		switch strings.ToLower(strings.TrimSpace(value)) {
-		case "1", "true", "yes", "on":
-			return true
-		case "0", "false", "no", "off":
-			return false
-		}
-	}
-	return defaultValue
-}
-
-func runtimeOptionInt64(options map[string]interface{}, key string, defaultValue int64) int64 {
-	if options == nil {
-		return defaultValue
-	}
-	raw, ok := options[key]
-	if !ok || raw == nil {
-		return defaultValue
-	}
-	switch value := raw.(type) {
-	case int:
-		return int64(value)
-	case int32:
-		return int64(value)
-	case int64:
-		return value
-	case float32:
-		return int64(value)
-	case float64:
-		return int64(value)
-	case string:
-		value = strings.TrimSpace(value)
-		if value == "" {
-			return defaultValue
-		}
-		var parsed int64
-		if _, err := fmt.Sscanf(value, "%d", &parsed); err == nil {
-			return parsed
-		}
-	}
-	return defaultValue
-}
-
-func runtimeOptionHasKey(options map[string]interface{}, key string) bool {
-	if options == nil {
-		return false
-	}
-	_, exists := options[key]
-	return exists
-}
-
-func decodeRuntimeBytesString(input, encoding string) ([]byte, error) {
-	switch strings.ToLower(strings.TrimSpace(encoding)) {
-	case "", "utf8", "utf-8", "text":
-		return []byte(input), nil
-	case "base64":
-		decoded, err := base64.StdEncoding.DecodeString(strings.TrimSpace(input))
-		if err != nil {
-			return nil, fmt.Errorf("invalid base64 data: %w", err)
-		}
-		return decoded, nil
-	case "hex":
-		decoded, err := hex.DecodeString(strings.TrimSpace(input))
-		if err != nil {
-			return nil, fmt.Errorf("invalid hex data: %w", err)
-		}
-		return decoded, nil
-	default:
-		return nil, fmt.Errorf("unsupported byte encoding: %s", encoding)
-	}
-}
-
-func decodeRuntimeBytesValue(raw interface{}, encoding string) ([]byte, error) {
-	switch value := raw.(type) {
-	case string:
-		return decodeRuntimeBytesString(value, encoding)
-	case []byte:
-		cloned := make([]byte, len(value))
-		copy(cloned, value)
-		return cloned, nil
-	case []interface{}:
-		decoded := make([]byte, len(value))
-		for i, item := range value {
-			switch num := item.(type) {
-			case int:
-				decoded[i] = byte(num)
-			case int64:
-				decoded[i] = byte(num)
-			case float64:
-				decoded[i] = byte(int(num))
-			default:
-				return nil, fmt.Errorf("unsupported byte array item at index %d", i)
-			}
-		}
-		return decoded, nil
-	default:
-		return nil, fmt.Errorf("unsupported byte payload type")
-	}
-}
-
-func encodeRuntimeBytes(data []byte, encoding string) (string, error) {
-	switch strings.ToLower(strings.TrimSpace(encoding)) {
-	case "", "base64":
-		return base64.StdEncoding.EncodeToString(data), nil
-	case "hex":
-		return hex.EncodeToString(data), nil
-	case "utf8", "utf-8", "text":
-		return string(data), nil
-	default:
-		return "", fmt.Errorf("unsupported byte encoding: %s", encoding)
-	}
-}
-
-func parseRuntimeBlockCipherOptions(options map[string]interface{}) (*runtimeBlockCipherOptions, error) {
-	parsed := &runtimeBlockCipherOptions{
-		Algorithm:      strings.ToLower(runtimeOptionString(options, "algorithm", "")),
-		Mode:           strings.ToLower(runtimeOptionString(options, "mode", "cbc")),
-		InputEncoding:  strings.ToLower(runtimeOptionString(options, "inputEncoding", "base64")),
-		OutputEncoding: strings.ToLower(runtimeOptionString(options, "outputEncoding", "base64")),
-		Padding:        strings.ToLower(runtimeOptionString(options, "padding", "none")),
-	}
-	if parsed.Algorithm == "" {
-		return nil, fmt.Errorf("algorithm is required")
-	}
-	if parsed.Mode == "" {
-		return nil, fmt.Errorf("mode is required")
-	}
-
-	key, err := decodeRuntimeBytesString(runtimeOptionString(options, "key", ""), runtimeOptionString(options, "keyEncoding", "utf8"))
-	if err != nil {
-		return nil, fmt.Errorf("invalid key: %w", err)
-	}
-	if len(key) == 0 {
-		return nil, fmt.Errorf("key is required")
-	}
-	parsed.Key = key
-
-	iv, err := decodeRuntimeBytesString(runtimeOptionString(options, "iv", ""), runtimeOptionString(options, "ivEncoding", "utf8"))
-	if err != nil {
-		return nil, fmt.Errorf("invalid iv: %w", err)
-	}
-	parsed.IV = iv
-	return parsed, nil
-}
-
-func newRuntimeBlockCipher(options *runtimeBlockCipherOptions) (cipher.Block, error) {
-	switch options.Algorithm {
-	case "blowfish":
-		return blowfish.NewCipher(options.Key)
-	case "aes":
-		return aes.NewCipher(options.Key)
-	default:
-		return nil, fmt.Errorf("unsupported block cipher algorithm: %s", options.Algorithm)
-	}
-}
-
-func applyPKCS7Padding(data []byte, blockSize int) []byte {
-	padding := blockSize - (len(data) % blockSize)
-	if padding == 0 {
-		padding = blockSize
-	}
-	out := make([]byte, len(data)+padding)
-	copy(out, data)
-	for i := len(data); i < len(out); i++ {
-		out[i] = byte(padding)
-	}
-	return out
-}
-
-func removePKCS7Padding(data []byte, blockSize int) ([]byte, error) {
-	if len(data) == 0 || len(data)%blockSize != 0 {
-		return nil, fmt.Errorf("invalid padded payload length")
-	}
-	padding := int(data[len(data)-1])
-	if padding <= 0 || padding > blockSize || padding > len(data) {
-		return nil, fmt.Errorf("invalid PKCS7 padding")
-	}
-	for i := len(data) - padding; i < len(data); i++ {
-		if int(data[i]) != padding {
-			return nil, fmt.Errorf("invalid PKCS7 padding")
-		}
-	}
-	return data[:len(data)-padding], nil
-}
-
-func (r *extensionRuntime) transformBlockCipher(call goja.FunctionCall, decrypt bool) goja.Value {
-	if len(call.Arguments) < 2 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "data and options are required",
-		})
-	}
-
-	options := parseRuntimeOptionsArgument(call, 1)
-	parsedOptions, err := parseRuntimeBlockCipherOptions(options)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-	if parsedOptions.Mode != "cbc" {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("unsupported block cipher mode: %s", parsedOptions.Mode),
-		})
-	}
-
-	inputData, err := decodeRuntimeBytesValue(call.Arguments[0].Export(), parsedOptions.InputEncoding)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	block, err := newRuntimeBlockCipher(parsedOptions)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	if len(parsedOptions.IV) != block.BlockSize() {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("iv must be %d bytes for %s", block.BlockSize(), parsedOptions.Algorithm),
-		})
-	}
-
-	data := inputData
-	if !decrypt && parsedOptions.Padding == "pkcs7" {
-		data = applyPKCS7Padding(data, block.BlockSize())
-	}
-	if len(data)%block.BlockSize() != 0 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("input length must be a multiple of %d bytes", block.BlockSize()),
-		})
-	}
-
-	output := make([]byte, len(data))
-	if decrypt {
-		cipher.NewCBCDecrypter(block, parsedOptions.IV).CryptBlocks(output, data)
-		if parsedOptions.Padding == "pkcs7" {
-			output, err = removePKCS7Padding(output, block.BlockSize())
-			if err != nil {
-				return r.vm.ToValue(map[string]interface{}{
-					"success": false,
-					"error":   err.Error(),
-				})
-			}
-		}
-	} else {
-		cipher.NewCBCEncrypter(block, parsedOptions.IV).CryptBlocks(output, data)
-	}
-
-	encoded, err := encodeRuntimeBytes(output, parsedOptions.OutputEncoding)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	return r.vm.ToValue(map[string]interface{}{
-		"success":    true,
-		"data":       encoded,
-		"block_size": block.BlockSize(),
-	})
-}
-
-func (r *extensionRuntime) encryptBlockCipher(call goja.FunctionCall) goja.Value {
-	return r.transformBlockCipher(call, false)
-}
-
-func (r *extensionRuntime) decryptBlockCipher(call goja.FunctionCall) goja.Value {
-	return r.transformBlockCipher(call, true)
-}

go_backend/extension_runtime_binary_test.go

@@ -1,185 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"testing"
-
-	"github.com/dop251/goja"
-)
-
-func newBinaryTestRuntime(t *testing.T, withFilePermission bool) *goja.Runtime {
-	t.Helper()
-
-	ext := &loadedExtension{
-		ID: "binary-test-ext",
-		Manifest: &ExtensionManifest{
-			Name: "binary-test-ext",
-			Permissions: ExtensionPermissions{
-				File: withFilePermission,
-			},
-		},
-		DataDir: t.TempDir(),
-	}
-
-	runtime := newExtensionRuntime(ext)
-	vm := goja.New()
-	runtime.RegisterAPIs(vm)
-	return vm
-}
-
-func decodeJSONResult[T any](t *testing.T, value goja.Value) T {
-	t.Helper()
-
-	var decoded T
-	if err := json.Unmarshal([]byte(value.String()), &decoded); err != nil {
-		t.Fatalf("failed to decode JSON result: %v", err)
-	}
-	return decoded
-}
-
-func TestExtensionRuntime_FileByteAPIs(t *testing.T) {
-	vm := newBinaryTestRuntime(t, true)
-
-	result, err := vm.RunString(`
-		(function() {
-			var first = file.writeBytes("bytes.bin", "AAEC", {encoding: "base64", truncate: true});
-			if (!first.success) throw new Error(first.error);
-
-			var second = file.writeBytes("bytes.bin", "0304ff", {encoding: "hex", append: true});
-			if (!second.success) throw new Error(second.error);
-
-			var all = file.readBytes("bytes.bin", {encoding: "hex"});
-			if (!all.success) throw new Error(all.error);
-
-			var slice = file.readBytes("bytes.bin", {offset: 2, length: 2, encoding: "hex"});
-			if (!slice.success) throw new Error(slice.error);
-
-			var tail = file.readBytes("bytes.bin", {offset: 6, length: 4, encoding: "hex"});
-			if (!tail.success) throw new Error(tail.error);
-
-			return JSON.stringify({
-				all: all.data,
-				slice: slice.data,
-				size: all.size,
-				sliceBytes: slice.bytes_read,
-				sliceEof: slice.eof,
-				tailBytes: tail.bytes_read,
-				tailEof: tail.eof
-			});
-		})()
-	`)
-	if err != nil {
-		t.Fatalf("file byte APIs failed: %v", err)
-	}
-
-	decoded := decodeJSONResult[struct {
-		All        string `json:"all"`
-		Slice      string `json:"slice"`
-		Size       int64  `json:"size"`
-		SliceBytes int    `json:"sliceBytes"`
-		SliceEof   bool   `json:"sliceEof"`
-		TailBytes  int    `json:"tailBytes"`
-		TailEof    bool   `json:"tailEof"`
-	}](t, result)
-
-	if decoded.All != "0001020304ff" {
-		t.Fatalf("all = %q", decoded.All)
-	}
-	if decoded.Slice != "0203" {
-		t.Fatalf("slice = %q", decoded.Slice)
-	}
-	if decoded.Size != 6 {
-		t.Fatalf("size = %d", decoded.Size)
-	}
-	if decoded.SliceBytes != 2 {
-		t.Fatalf("slice bytes = %d", decoded.SliceBytes)
-	}
-	if decoded.SliceEof {
-		t.Fatal("slice should not be EOF")
-	}
-	if decoded.TailBytes != 0 || !decoded.TailEof {
-		t.Fatalf("tail read mismatch: bytes=%d eof=%v", decoded.TailBytes, decoded.TailEof)
-	}
-}
-
-func TestExtensionRuntime_BlockCipherCBCSupportsBlowfish(t *testing.T) {
-	vm := newBinaryTestRuntime(t, false)
-
-	result, err := vm.RunString(`
-		(function() {
-			var options = {
-				algorithm: "blowfish",
-				mode: "cbc",
-				key: "0123456789ABCDEFF0E1D2C3B4A59687",
-				keyEncoding: "hex",
-				iv: "0001020304050607",
-				ivEncoding: "hex",
-				inputEncoding: "hex",
-				outputEncoding: "hex",
-				padding: "none"
-			};
-			var enc = utils.encryptBlockCipher("00112233445566778899aabbccddeeff", options);
-			if (!enc.success) throw new Error(enc.error);
-			var dec = utils.decryptBlockCipher(enc.data, options);
-			if (!dec.success) throw new Error(dec.error);
-			return JSON.stringify({enc: enc.data, dec: dec.data});
-		})()
-	`)
-	if err != nil {
-		t.Fatalf("blowfish block cipher failed: %v", err)
-	}
-
-	decoded := decodeJSONResult[struct {
-		Enc string `json:"enc"`
-		Dec string `json:"dec"`
-	}](t, result)
-
-	if decoded.Dec != "00112233445566778899aabbccddeeff" {
-		t.Fatalf("dec = %q", decoded.Dec)
-	}
-	if decoded.Enc == decoded.Dec {
-		t.Fatal("expected ciphertext to differ from plaintext")
-	}
-}
-
-func TestExtensionRuntime_BlockCipherCBCSupportsAES(t *testing.T) {
-	vm := newBinaryTestRuntime(t, false)
-
-	result, err := vm.RunString(`
-		(function() {
-			var options = {
-				algorithm: "aes",
-				mode: "cbc",
-				key: "000102030405060708090a0b0c0d0e0f",
-				keyEncoding: "hex",
-				iv: "0f0e0d0c0b0a09080706050403020100",
-				ivEncoding: "hex",
-				inputEncoding: "utf8",
-				outputEncoding: "base64",
-				padding: "pkcs7"
-			};
-			var enc = utils.encryptBlockCipher("hello generic cbc", options);
-			if (!enc.success) throw new Error(enc.error);
-			var dec = utils.decryptBlockCipher(enc.data, {
-				algorithm: "aes",
-				mode: "cbc",
-				key: options.key,
-				keyEncoding: options.keyEncoding,
-				iv: options.iv,
-				ivEncoding: options.ivEncoding,
-				inputEncoding: "base64",
-				outputEncoding: "utf8",
-				padding: "pkcs7"
-			});
-			if (!dec.success) throw new Error(dec.error);
-			return dec.data;
-		})()
-	`)
-	if err != nil {
-		t.Fatalf("aes block cipher failed: %v", err)
-	}
-
-	if result.String() != "hello generic cbc" {
-		t.Fatalf("unexpected decrypted value: %q", result.String())
-	}
-}

go_backend/extension_runtime_ffmpeg.go

@@ -50,7 +50,7 @@ func ClearFFmpegCommand(commandID string) {
 	delete(ffmpegCommands, commandID)
 }
 
-func (r *extensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -107,7 +107,7 @@ func (r *extensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	}
 }
 
-func (r *extensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -134,7 +134,7 @@ func (r *extensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) ffmpegConvert(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) ffmpegConvert(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,

go_backend/extension_runtime_file.go

@@ -8,7 +8,6 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
-	"time"
 
 	"github.com/dop251/goja"
 )
@@ -72,7 +71,7 @@ func isPathWithinBase(baseDir, targetPath string) bool {
 	return true
 }
 
-func (r *extensionRuntime) validatePath(path string) (string, error) {
+func (r *ExtensionRuntime) validatePath(path string) (string, error) {
 	if !r.manifest.Permissions.File {
 		return "", fmt.Errorf("file access denied: extension does not have 'file' permission")
 	}
@@ -107,7 +106,7 @@ func (r *extensionRuntime) validatePath(path string) (string, error) {
 	return absPath, nil
 }
 
-func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -135,8 +134,6 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 
 	var onProgress goja.Callable
 	var headers map[string]string
-	var chunkedDownload bool
-	var chunkSize int64
 	if len(call.Arguments) > 2 && !goja.IsUndefined(call.Arguments[2]) && !goja.IsNull(call.Arguments[2]) {
 		optionsObj := call.Arguments[2].Export()
 		if opts, ok := optionsObj.(map[string]interface{}); ok {
@@ -151,30 +148,9 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 					onProgress = callable
 				}
 			}
-			if chunked, ok := opts["chunked"]; ok {
-				switch v := chunked.(type) {
-				case bool:
-					chunkedDownload = v
-				case int64:
-					if v > 0 {
-						chunkedDownload = true
-						chunkSize = v
-					}
-				case float64:
-					if v > 0 {
-						chunkedDownload = true
-						chunkSize = int64(v)
-					}
-				}
-			}
 		}
 	}
 
-	// Default chunk size: 1MB (YouTube CDN max without poToken)
-	if chunkedDownload && chunkSize <= 0 {
-		chunkSize = 1024 * 1024
-	}
-
 	dir := filepath.Dir(fullPath)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -183,20 +159,6 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	client := r.downloadClient
-	if client == nil {
-		client = r.httpClient
-	}
-
-	ua := appUserAgent()
-	if h, ok := headers["User-Agent"]; ok && h != "" {
-		ua = h
-	}
-
-	if chunkedDownload {
-		return r.fileDownloadChunked(client, urlStr, fullPath, headers, ua, chunkSize, onProgress)
-	}
-
 	req, err := http.NewRequest("GET", urlStr, nil)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -204,13 +166,17 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 			"error":   err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
 	if req.Header.Get("User-Agent") == "" {
-		req.Header.Set("User-Agent", appUserAgent())
+		req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")
+	}
+
+	client := r.downloadClient
+	if client == nil {
+		client = r.httpClient
 	}
 
 	resp, err := client.Do(req)
@@ -222,7 +188,7 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+	if resp.StatusCode != 200 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
 			"error":   fmt.Sprintf("HTTP error: %d", resp.StatusCode),
@@ -238,19 +204,14 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	}
 	defer out.Close()
 
-	activeItemID := r.getActiveDownloadItemID()
-	if activeItemID != "" {
-		SetItemDownloading(activeItemID)
-	}
-
 	contentLength := resp.ContentLength
-	shouldTrackItemBytes := activeItemID != "" && onProgress == nil
-	if shouldTrackItemBytes && contentLength > 0 {
+	activeItemID := r.getActiveDownloadItemID()
+	if activeItemID != "" && contentLength > 0 {
 		SetItemBytesTotal(activeItemID, contentLength)
 	}
 
 	var progressWriter interface{ Write([]byte) (int, error) } = out
-	if shouldTrackItemBytes {
+	if activeItemID != "" {
 		progressWriter = NewItemProgressWriter(out, activeItemID)
 	}
 
@@ -310,232 +271,7 @@ func (r *extensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileDownloadChunked downloads a URL using sequential Range requests.
-// This is needed for servers (like YouTube's googlevideo CDN) that reject
-// non-ranged or large-range requests with 403 and require small chunk downloads.
-func (r *extensionRuntime) fileDownloadChunked(client *http.Client, urlStr, fullPath string, headers map[string]string, ua string, chunkSize int64, onProgress goja.Callable) goja.Value {
-	// First, get the total content length with a small probe request
-	probeReq, err := http.NewRequest("GET", urlStr, nil)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("chunked: probe request error: %v", err),
-		})
-	}
-	probeReq = r.bindDownloadCancelContext(probeReq)
-	probeReq.Header.Set("User-Agent", ua)
-	for k, v := range headers {
-		if k != "Range" { // Don't copy any existing Range header
-			probeReq.Header.Set(k, v)
-		}
-	}
-	probeReq.Header.Set("Range", "bytes=0-1")
-
-	probeResp, err := client.Do(probeReq)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("chunked: probe error: %v", err),
-		})
-	}
-	io.Copy(io.Discard, probeResp.Body)
-	probeResp.Body.Close()
-
-	if probeResp.StatusCode != 206 && probeResp.StatusCode != 200 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("chunked: probe HTTP %d", probeResp.StatusCode),
-		})
-	}
-
-	// Parse Content-Range to get total size: "bytes 0-1/TOTAL"
-	var totalSize int64
-	contentRange := probeResp.Header.Get("Content-Range")
-	if contentRange != "" {
-		// Format: "bytes 0-1/12345"
-		if idx := strings.LastIndex(contentRange, "/"); idx >= 0 {
-			sizeStr := contentRange[idx+1:]
-			if sizeStr != "*" {
-				fmt.Sscanf(sizeStr, "%d", &totalSize)
-			}
-		}
-	}
-
-	if totalSize <= 0 {
-		// Fallback: try Content-Length from a HEAD-like approach
-		// If we can't determine size, download with unknown size
-		GoLog("[Extension:%s] Chunked download: unknown total size, will download until server says done\n", r.extensionID)
-	} else {
-		GoLog("[Extension:%s] Chunked download: total size %d bytes, chunk size %d\n", r.extensionID, totalSize, chunkSize)
-	}
-
-	out, err := os.Create(fullPath)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("failed to create file: %v", err),
-		})
-	}
-	defer out.Close()
-
-	activeItemID := r.getActiveDownloadItemID()
-	if activeItemID != "" {
-		SetItemDownloading(activeItemID)
-	}
-
-	shouldTrackItemBytes := activeItemID != "" && onProgress == nil
-	if shouldTrackItemBytes && totalSize > 0 {
-		SetItemBytesTotal(activeItemID, totalSize)
-	}
-
-	var progressWriter interface{ Write([]byte) (int, error) } = out
-	if shouldTrackItemBytes {
-		progressWriter = NewItemProgressWriter(out, activeItemID)
-	}
-
-	var totalWritten int64
-	buf := make([]byte, 32*1024)
-	maxRetries := 3
-
-	for offset := int64(0); totalSize <= 0 || offset < totalSize; {
-		end := offset + chunkSize - 1
-		if totalSize > 0 && end >= totalSize {
-			end = totalSize - 1
-		}
-
-		var chunkResp *http.Response
-		var chunkErr error
-
-		for retry := 0; retry < maxRetries; retry++ {
-			chunkReq, err := http.NewRequest("GET", urlStr, nil)
-			if err != nil {
-				return r.vm.ToValue(map[string]interface{}{
-					"success": false,
-					"error":   fmt.Sprintf("chunked: request error at offset %d: %v", offset, err),
-				})
-			}
-			chunkReq = r.bindDownloadCancelContext(chunkReq)
-			chunkReq.Header.Set("User-Agent", ua)
-			for k, v := range headers {
-				if k != "Range" {
-					chunkReq.Header.Set(k, v)
-				}
-			}
-			chunkReq.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", offset, end))
-
-			chunkResp, chunkErr = client.Do(chunkReq)
-			if chunkErr != nil {
-				if retry < maxRetries-1 {
-					time.Sleep(time.Duration(retry+1) * time.Second)
-					continue
-				}
-				return r.vm.ToValue(map[string]interface{}{
-					"success": false,
-					"error":   fmt.Sprintf("chunked: error at offset %d after %d retries: %v", offset, maxRetries, chunkErr),
-				})
-			}
-
-			if chunkResp.StatusCode == 206 || chunkResp.StatusCode == 200 {
-				break // Success
-			}
-
-			// Non-success status
-			io.Copy(io.Discard, chunkResp.Body)
-			chunkResp.Body.Close()
-
-			if chunkResp.StatusCode == 403 || chunkResp.StatusCode == 429 {
-				if retry < maxRetries-1 {
-					time.Sleep(time.Duration(retry+1) * 2 * time.Second)
-					continue
-				}
-			}
-
-			return r.vm.ToValue(map[string]interface{}{
-				"success": false,
-				"error":   fmt.Sprintf("chunked: HTTP %d at offset %d", chunkResp.StatusCode, offset),
-			})
-		}
-
-		// Read chunk body and write to file
-		chunkWritten := int64(0)
-		for {
-			nr, er := chunkResp.Body.Read(buf)
-			if nr > 0 {
-				nw, ew := progressWriter.Write(buf[0:nr])
-				if nw < 0 || nr < nw {
-					nw = 0
-					if ew == nil {
-						ew = fmt.Errorf("invalid write result")
-					}
-				}
-				chunkWritten += int64(nw)
-				totalWritten += int64(nw)
-				if ew != nil {
-					chunkResp.Body.Close()
-					if ew == ErrDownloadCancelled {
-						return r.vm.ToValue(map[string]interface{}{
-							"success": false,
-							"error":   "download cancelled",
-						})
-					}
-					return r.vm.ToValue(map[string]interface{}{
-						"success": false,
-						"error":   fmt.Sprintf("failed to write file: %v", ew),
-					})
-				}
-				if nr != nw {
-					chunkResp.Body.Close()
-					return r.vm.ToValue(map[string]interface{}{
-						"success": false,
-						"error":   "short write",
-					})
-				}
-
-				if onProgress != nil && totalSize > 0 {
-					_, _ = onProgress(goja.Undefined(), r.vm.ToValue(totalWritten), r.vm.ToValue(totalSize))
-				}
-			}
-			if er != nil {
-				if er != io.EOF {
-					chunkResp.Body.Close()
-					return r.vm.ToValue(map[string]interface{}{
-						"success": false,
-						"error":   fmt.Sprintf("failed to read chunk at offset %d: %v", offset, er),
-					})
-				}
-				break
-			}
-		}
-		chunkResp.Body.Close()
-
-		offset += chunkWritten
-
-		// If server returned 200 (full content) instead of 206, we're done
-		if chunkResp.StatusCode == 200 {
-			break
-		}
-
-		// If we got less data than expected and we know total size, check if done
-		if totalSize > 0 && offset >= totalSize {
-			break
-		}
-
-		// Unknown size: if we got less than chunk size, assume done
-		if totalSize <= 0 && chunkWritten < chunkSize {
-			break
-		}
-	}
-
-	GoLog("[Extension:%s] Chunked download complete: %d bytes to %s\n", r.extensionID, totalWritten, fullPath)
-
-	return r.vm.ToValue(map[string]interface{}{
-		"success": true,
-		"path":    fullPath,
-		"size":    totalWritten,
-	})
-}
-
-func (r *extensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -550,7 +286,7 @@ func (r *extensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(err == nil)
 }
 
-func (r *extensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -579,7 +315,7 @@ func (r *extensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -610,105 +346,7 @@ func (r *extensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) fileReadBytes(call goja.FunctionCall) goja.Value {
-	if len(call.Arguments) < 1 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "path is required",
-		})
-	}
-
-	path := call.Arguments[0].String()
-	fullPath, err := r.validatePath(path)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	options := parseRuntimeOptionsArgument(call, 1)
-	offset := runtimeOptionInt64(options, "offset", 0)
-	length := runtimeOptionInt64(options, "length", -1)
-	encoding := runtimeOptionString(options, "encoding", "base64")
-	if offset < 0 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "offset must be >= 0",
-		})
-	}
-
-	file, err := os.Open(fullPath)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-	defer file.Close()
-
-	info, err := file.Stat()
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	size := info.Size()
-	if offset > size {
-		offset = size
-	}
-	if _, err := file.Seek(offset, io.SeekStart); err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("failed to seek file: %v", err),
-		})
-	}
-
-	var data []byte
-	switch {
-	case length == 0:
-		data = []byte{}
-	case length > 0:
-		buf := make([]byte, int(length))
-		n, readErr := file.Read(buf)
-		if readErr != nil && readErr != io.EOF {
-			return r.vm.ToValue(map[string]interface{}{
-				"success": false,
-				"error":   fmt.Sprintf("failed to read file: %v", readErr),
-			})
-		}
-		data = buf[:n]
-	default:
-		data, err = io.ReadAll(file)
-		if err != nil {
-			return r.vm.ToValue(map[string]interface{}{
-				"success": false,
-				"error":   fmt.Sprintf("failed to read file: %v", err),
-			})
-		}
-	}
-
-	encoded, err := encodeRuntimeBytes(data, encoding)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	return r.vm.ToValue(map[string]interface{}{
-		"success":    true,
-		"data":       encoded,
-		"bytes_read": len(data),
-		"offset":     offset,
-		"size":       size,
-		"eof":        offset+int64(len(data)) >= size,
-	})
-}
-
-func (r *extensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -748,108 +386,7 @@ func (r *extensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) fileWriteBytes(call goja.FunctionCall) goja.Value {
-	if len(call.Arguments) < 2 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "path and data are required",
-		})
-	}
-
-	path := call.Arguments[0].String()
-	fullPath, err := r.validatePath(path)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	options := parseRuntimeOptionsArgument(call, 2)
-	appendMode := runtimeOptionBool(options, "append", false)
-	truncate := runtimeOptionBool(options, "truncate", false)
-	hasOffset := runtimeOptionHasKey(options, "offset")
-	offset := runtimeOptionInt64(options, "offset", 0)
-	encoding := runtimeOptionString(options, "encoding", "base64")
-
-	if appendMode && hasOffset {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "append and offset cannot be used together",
-		})
-	}
-	if offset < 0 {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   "offset must be >= 0",
-		})
-	}
-
-	data, err := decodeRuntimeBytesValue(call.Arguments[1].Export(), encoding)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	dir := filepath.Dir(fullPath)
-	if err := os.MkdirAll(dir, 0755); err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   fmt.Sprintf("failed to create directory: %v", err),
-		})
-	}
-
-	flags := os.O_CREATE | os.O_WRONLY
-	if appendMode {
-		flags |= os.O_APPEND
-	}
-	if truncate {
-		flags |= os.O_TRUNC
-	}
-
-	file, err := os.OpenFile(fullPath, flags, 0644)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-	defer file.Close()
-
-	if hasOffset && !appendMode {
-		if _, err := file.Seek(offset, io.SeekStart); err != nil {
-			return r.vm.ToValue(map[string]interface{}{
-				"success": false,
-				"error":   fmt.Sprintf("failed to seek file: %v", err),
-			})
-		}
-	}
-
-	written, err := file.Write(data)
-	if err != nil {
-		return r.vm.ToValue(map[string]interface{}{
-			"success": false,
-			"error":   err.Error(),
-		})
-	}
-
-	info, statErr := file.Stat()
-	size := int64(0)
-	if statErr == nil {
-		size = info.Size()
-	}
-
-	return r.vm.ToValue(map[string]interface{}{
-		"success":       true,
-		"path":          fullPath,
-		"bytes_written": written,
-		"size":          size,
-	})
-}
-
-func (r *extensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -922,7 +459,7 @@ func (r *extensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -970,7 +507,7 @@ func (r *extensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) fileGetSize(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) fileGetSize(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,

go_backend/extension_runtime_http.go

@@ -17,25 +17,7 @@ type HTTPResponse struct {
 	Headers    map[string]string `json:"headers"`
 }
 
-const maxExtensionHTTPResponseBytes = 16 << 20
-
-func readExtensionHTTPResponseBody(resp *http.Response) ([]byte, error) {
-	body, err := io.ReadAll(
-		io.LimitReader(resp.Body, maxExtensionHTTPResponseBytes+1),
-	)
-	if err != nil {
-		return nil, err
-	}
-	if len(body) > maxExtensionHTTPResponseBytes {
-		return nil, fmt.Errorf(
-			"response body exceeds %d byte limit; use file.download for large media",
-			maxExtensionHTTPResponseBytes,
-		)
-	}
-	return body, nil
-}
-
-func (r *extensionRuntime) validateDomain(urlStr string) error {
+func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	parsed, err := url.Parse(urlStr)
 	if err != nil {
 		return fmt.Errorf("invalid URL: %w", err)
@@ -44,8 +26,7 @@ func (r *extensionRuntime) validateDomain(urlStr string) error {
 	if parsed.Scheme == "" {
 		return fmt.Errorf("invalid URL: scheme is required")
 	}
-	if parsed.Scheme != "https" &&
-		!(parsed.Scheme == "http" && r.manifest.Permissions.AllowHTTP) {
+	if parsed.Scheme != "https" {
 		return fmt.Errorf("network access denied: only https is allowed")
 	}
 	if parsed.User != nil {
@@ -68,7 +49,7 @@ func (r *extensionRuntime) validateDomain(urlStr string) error {
 	return nil
 }
 
-func (r *extensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -100,7 +81,6 @@ func (r *extensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -118,7 +98,7 @@ func (r *extensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	body, err := readExtensionHTTPResponseBody(resp)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": err.Error(),
@@ -138,13 +118,12 @@ func (r *extensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		"statusCode": resp.StatusCode,
 		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
-		"url":        resp.Request.URL.String(),
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-func (r *extensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -195,7 +174,6 @@ func (r *extensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -216,7 +194,7 @@ func (r *extensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	body, err := readExtensionHTTPResponseBody(resp)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": err.Error(),
@@ -236,13 +214,12 @@ func (r *extensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		"statusCode": resp.StatusCode,
 		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
-		"url":        resp.Request.URL.String(),
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-func (r *extensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -305,7 +282,6 @@ func (r *extensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 			"error": err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -326,7 +302,7 @@ func (r *extensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	body, err := readExtensionHTTPResponseBody(resp)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": err.Error(),
@@ -346,25 +322,24 @@ func (r *extensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		"statusCode": resp.StatusCode,
 		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
-		"url":        resp.Request.URL.String(),
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-func (r *extensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PUT", call)
 }
 
-func (r *extensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("DELETE", call)
 }
 
-func (r *extensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PATCH", call)
 }
 
-func (r *extensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": "URL is required",
@@ -432,7 +407,6 @@ func (r *extensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 			"error": err.Error(),
 		})
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
@@ -452,7 +426,7 @@ func (r *extensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	}
 	defer resp.Body.Close()
 
-	body, err := readExtensionHTTPResponseBody(resp)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"error": err.Error(),
@@ -472,13 +446,12 @@ func (r *extensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		"statusCode": resp.StatusCode,
 		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
-		"url":        resp.Request.URL.String(),
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-func (r *extensionRuntime) httpClearCookies(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) httpClearCookies(call goja.FunctionCall) goja.Value {
 	if jar, ok := r.cookieJar.(*simpleCookieJar); ok {
 		jar.mu.Lock()
 		jar.cookies = make(map[string][]*http.Cookie)

go_backend/extension_runtime_matching.go

@@ -6,7 +6,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *extensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(0.0)
 	}
@@ -22,7 +22,7 @@ func (r *extensionRuntime) matchingCompareStrings(call goja.FunctionCall) goja.V
 	return r.vm.ToValue(similarity)
 }
 
-func (r *extensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
 	}
@@ -43,7 +43,7 @@ func (r *extensionRuntime) matchingCompareDuration(call goja.FunctionCall) goja.
 	return r.vm.ToValue(diff <= tolerance)
 }
 
-func (r *extensionRuntime) matchingNormalizeString(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) matchingNormalizeString(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}

go_backend/extension_runtime_polyfills.go

@@ -12,7 +12,11 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
+// These polyfills make porting browser/Node.js libraries easier
+// without compromising sandbox security.
+
+// Returns a Promise-like object with json(), text() methods.
+func (r *ExtensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.createFetchError("URL is required")
 	}
@@ -34,6 +38,7 @@ func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 				method = strings.ToUpper(m)
 			}
 
+			// Body - support string, object (auto-stringify), or nil
 			if bodyArg, ok := opts["body"]; ok && bodyArg != nil {
 				switch v := bodyArg.(type) {
 				case string:
@@ -69,13 +74,12 @@ func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	if err != nil {
 		return r.createFetchError(err.Error())
 	}
-	req = r.bindDownloadCancelContext(req)
 
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
 	if req.Header.Get("User-Agent") == "" {
-		req.Header.Set("User-Agent", appUserAgent())
+		req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")
 	}
 	if bodyStr != "" && req.Header.Get("Content-Type") == "" {
 		req.Header.Set("Content-Type", "application/json")
@@ -106,7 +110,7 @@ func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	responseObj.Set("status", resp.StatusCode)
 	responseObj.Set("statusText", http.StatusText(resp.StatusCode))
 	responseObj.Set("headers", respHeaders)
-	responseObj.Set("url", resp.Request.URL.String())
+	responseObj.Set("url", urlStr)
 
 	bodyString := string(body)
 
@@ -134,7 +138,7 @@ func (r *extensionRuntime) fetchPolyfill(call goja.FunctionCall) goja.Value {
 	return responseObj
 }
 
-func (r *extensionRuntime) createFetchError(message string) goja.Value {
+func (r *ExtensionRuntime) createFetchError(message string) goja.Value {
 	errorObj := r.vm.NewObject()
 	errorObj.Set("ok", false)
 	errorObj.Set("status", 0)
@@ -149,7 +153,7 @@ func (r *extensionRuntime) createFetchError(message string) goja.Value {
 	return errorObj
 }
 
-func (r *extensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -165,7 +169,7 @@ func (r *extensionRuntime) atobPolyfill(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-func (r *extensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -173,7 +177,7 @@ func (r *extensionRuntime) btoaPolyfill(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-func (r *extensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
+func (r *ExtensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
 	vm.Set("TextEncoder", func(call goja.ConstructorCall) *goja.Object {
 		encoder := call.This
 		encoder.Set("encoding", "utf-8")
@@ -193,6 +197,7 @@ func (r *extensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
 		})
 
 		encoder.Set("encodeInto", func(call goja.FunctionCall) goja.Value {
+			// Simplified implementation
 			if len(call.Arguments) < 2 {
 				return vm.ToValue(map[string]interface{}{"read": 0, "written": 0})
 			}
@@ -253,7 +258,7 @@ func (r *extensionRuntime) registerTextEncoderDecoder(vm *goja.Runtime) {
 	})
 }
 
-func (r *extensionRuntime) registerURLClass(vm *goja.Runtime) {
+func (r *ExtensionRuntime) registerURLClass(vm *goja.Runtime) {
 	vm.Set("URL", func(call goja.ConstructorCall) *goja.Object {
 		urlObj := call.This
 
@@ -417,7 +422,8 @@ func (r *extensionRuntime) registerURLClass(vm *goja.Runtime) {
 	})
 }
 
-func (r *extensionRuntime) registerJSONGlobal(vm *goja.Runtime) {
+// JSON is already built-in to Goja; this ensures a fallback exists.
+func (r *ExtensionRuntime) registerJSONGlobal(vm *goja.Runtime) {
 	jsonScript := `
 		if (typeof JSON === 'undefined') {
 			var JSON = {

go_backend/extension_runtime_storage.go

@@ -21,7 +21,7 @@ const (
 	storageFlushRetryDelay   = 2 * time.Second
 )
 
-func (r *extensionRuntime) getStoragePath() string {
+func (r *ExtensionRuntime) getStoragePath() string {
 	return filepath.Join(r.dataDir, "storage.json")
 }
 
@@ -36,7 +36,7 @@ func cloneInterfaceMap(src map[string]interface{}) map[string]interface{} {
 	return dst
 }
 
-func (r *extensionRuntime) ensureStorageLoaded() error {
+func (r *ExtensionRuntime) ensureStorageLoaded() error {
 	r.storageMu.RLock()
 	if r.storageLoaded {
 		r.storageMu.RUnlock()
@@ -74,7 +74,7 @@ func (r *extensionRuntime) ensureStorageLoaded() error {
 	return nil
 }
 
-func (r *extensionRuntime) loadStorage() (map[string]interface{}, error) {
+func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	if err := r.ensureStorageLoaded(); err != nil {
 		return nil, err
 	}
@@ -84,7 +84,7 @@ func (r *extensionRuntime) loadStorage() (map[string]interface{}, error) {
 	return cloneInterfaceMap(r.storageCache), nil
 }
 
-func (r *extensionRuntime) queueStorageFlushLocked(delay time.Duration) {
+func (r *ExtensionRuntime) queueStorageFlushLocked(delay time.Duration) {
 	if r.storageClosed {
 		return
 	}
@@ -94,7 +94,7 @@ func (r *extensionRuntime) queueStorageFlushLocked(delay time.Duration) {
 	r.storageTimer = time.AfterFunc(delay, r.flushStorageDirtyAsync)
 }
 
-func (r *extensionRuntime) persistStorageSnapshot(storage map[string]interface{}) error {
+func (r *ExtensionRuntime) persistStorageSnapshot(storage map[string]interface{}) error {
 	data, err := json.Marshal(storage)
 	if err != nil {
 		return err
@@ -106,13 +106,13 @@ func (r *extensionRuntime) persistStorageSnapshot(storage map[string]interface{}
 	return os.WriteFile(r.getStoragePath(), data, 0600)
 }
 
-func (r *extensionRuntime) flushStorageDirtyAsync() {
+func (r *ExtensionRuntime) flushStorageDirtyAsync() {
 	if err := r.flushStorageDirty(); err != nil {
 		GoLog("[Extension:%s] Storage flush error: %v\n", r.extensionID, err)
 	}
 }
 
-func (r *extensionRuntime) flushStorageDirty() error {
+func (r *ExtensionRuntime) flushStorageDirty() error {
 	r.storageMu.Lock()
 	if r.storageClosed {
 		r.storageTimer = nil
@@ -140,7 +140,7 @@ func (r *extensionRuntime) flushStorageDirty() error {
 	return nil
 }
 
-func (r *extensionRuntime) flushStorageNow() error {
+func (r *ExtensionRuntime) flushStorageNow() error {
 	r.storageMu.Lock()
 	if r.storageTimer != nil {
 		r.storageTimer.Stop()
@@ -157,7 +157,7 @@ func (r *extensionRuntime) flushStorageNow() error {
 	return r.persistStorageSnapshot(snapshot)
 }
 
-func (r *extensionRuntime) closeStorageFlusher() {
+func (r *ExtensionRuntime) closeStorageFlusher() {
 	r.storageMu.Lock()
 	r.storageClosed = true
 	r.storageDirty = false
@@ -168,7 +168,7 @@ func (r *extensionRuntime) closeStorageFlusher() {
 	r.storageMu.Unlock()
 }
 
-func (r *extensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -193,7 +193,7 @@ func (r *extensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-func (r *extensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
 	}
@@ -225,7 +225,7 @@ func (r *extensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *extensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -254,15 +254,15 @@ func (r *extensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-func (r *extensionRuntime) getCredentialsPath() string {
+func (r *ExtensionRuntime) getCredentialsPath() string {
 	return filepath.Join(r.dataDir, ".credentials.enc")
 }
 
-func (r *extensionRuntime) getSaltPath() string {
+func (r *ExtensionRuntime) getSaltPath() string {
 	return filepath.Join(r.dataDir, ".cred_salt")
 }
 
-func (r *extensionRuntime) getOrCreateSalt() ([]byte, error) {
+func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	saltPath := r.getSaltPath()
 
 	salt, err := os.ReadFile(saltPath)
@@ -282,7 +282,7 @@ func (r *extensionRuntime) getOrCreateSalt() ([]byte, error) {
 	return salt, nil
 }
 
-func (r *extensionRuntime) getEncryptionKey() ([]byte, error) {
+func (r *ExtensionRuntime) getEncryptionKey() ([]byte, error) {
 	salt, err := r.getOrCreateSalt()
 	if err != nil {
 		return nil, err
@@ -293,7 +293,7 @@ func (r *extensionRuntime) getEncryptionKey() ([]byte, error) {
 	return hash[:], nil
 }
 
-func (r *extensionRuntime) ensureCredentialsLoaded() error {
+func (r *ExtensionRuntime) ensureCredentialsLoaded() error {
 	r.credentialsMu.RLock()
 	if r.credentialsLoaded {
 		r.credentialsMu.RUnlock()
@@ -340,7 +340,17 @@ func (r *extensionRuntime) ensureCredentialsLoaded() error {
 	return nil
 }
 
-func (r *extensionRuntime) saveCredentials(creds map[string]interface{}) error {
+func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
+	if err := r.ensureCredentialsLoaded(); err != nil {
+		return nil, err
+	}
+
+	r.credentialsMu.RLock()
+	defer r.credentialsMu.RUnlock()
+	return cloneInterfaceMap(r.credentialsCache), nil
+}
+
+func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	data, err := json.Marshal(creds)
 	if err != nil {
 		return err
@@ -367,7 +377,7 @@ func (r *extensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	return nil
 }
 
-func (r *extensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -404,7 +414,7 @@ func (r *extensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -429,7 +439,7 @@ func (r *extensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-func (r *extensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
@@ -454,7 +464,7 @@ func (r *extensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value
 	return r.vm.ToValue(true)
 }
 
-func (r *extensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}

go_backend/extension_runtime_storage_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func setStorageValue(t *testing.T, runtime *extensionRuntime, key string, value interface{}) {
+func setStorageValue(t *testing.T, runtime *ExtensionRuntime, key string, value interface{}) {
 	t.Helper()
 	result := runtime.storageSet(goja.FunctionCall{
 		Arguments: []goja.Value{
@@ -39,7 +39,7 @@ func readStorageMap(t *testing.T, storagePath string) map[string]interface{} {
 }
 
 func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID: "storage-test",
 		Manifest: &ExtensionManifest{
 			Name: "storage-test",
@@ -47,7 +47,7 @@ func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 	runtime.storageFlushDelay = 25 * time.Millisecond
 	runtime.RegisterAPIs(goja.New())
 
@@ -86,7 +86,7 @@ func TestExtensionRuntimeStorage_DebouncedWriteCompactJSON(t *testing.T) {
 }
 
 func TestUnloadExtension_FlushesPendingStorage(t *testing.T) {
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID: "unload-storage-test",
 		Manifest: &ExtensionManifest{
 			Name: "unload-storage-test",
@@ -95,13 +95,13 @@ func TestUnloadExtension_FlushesPendingStorage(t *testing.T) {
 		VM:      goja.New(),
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 	runtime.storageFlushDelay = time.Hour
 	runtime.RegisterAPIs(ext.VM)
 	ext.runtime = runtime
 
-	manager := &extensionManager{
-		extensions: map[string]*loadedExtension{
+	manager := &ExtensionManager{
+		extensions: map[string]*LoadedExtension{
 			ext.ID: ext,
 		},
 	}

go_backend/extension_runtime_supplement_test.go

@@ -1,747 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"fmt"
-	"io"
-	"net/http"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-	"time"
-
-	"github.com/dop251/goja"
-)
-
-func TestExtensionRuntimeAuthAndPolyfills(t *testing.T) {
-	vm := goja.New()
-	runtime := &extensionRuntime{
-		extensionID: "auth-ext",
-		manifest: &ExtensionManifest{
-			Name:        "auth-ext",
-			Description: "Auth extension",
-			Version:     "1.0.0",
-			Permissions: ExtensionPermissions{
-				Network: []string{"auth.example.com", "token.example.com", "api.example.com"},
-			},
-		},
-		settings: map[string]interface{}{},
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			switch req.URL.Host {
-			case "token.example.com":
-				return &http.Response{
-					StatusCode: 200,
-					Header:     make(http.Header),
-					Body:       io.NopCloser(strings.NewReader(`{"access_token":"access","refresh_token":"refresh","expires_in":3600}`)),
-					Request:    req,
-				}, nil
-			case "api.example.com":
-				return &http.Response{
-					StatusCode: 200,
-					Header:     http.Header{"X-Test": []string{"yes"}},
-					Body:       io.NopCloser(strings.NewReader(`{"ok":true,"items":[1,2]}`)),
-					Request:    req,
-				}, nil
-			default:
-				return &http.Response{StatusCode: 404, Body: io.NopCloser(strings.NewReader(`{}`)), Request: req}, nil
-			}
-		})},
-		vm: vm,
-	}
-
-	if err := validateExtensionAuthURL("https://user:pass@auth.example.com/login"); err == nil {
-		t.Fatal("expected embedded credential error")
-	}
-	if err := validateExtensionAuthURL("http://auth.example.com/login"); err == nil {
-		t.Fatal("expected non-https auth URL error")
-	}
-	if got := summarizeURLForLog("https://auth.example.com/login?token=secret"); got != "https://auth.example.com/login" {
-		t.Fatalf("summary = %q", got)
-	}
-
-	openResult := runtime.authOpenUrl(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("https://auth.example.com/login"),
-		vm.ToValue("app://callback"),
-	}}).Export().(map[string]interface{})
-	if openResult["success"] != true {
-		t.Fatalf("authOpenUrl = %#v", openResult)
-	}
-	if pending := GetPendingAuthRequest("auth-ext"); pending == nil || pending.AuthURL == "" {
-		t.Fatalf("pending auth = %#v", pending)
-	}
-	if code := runtime.authGetCode(goja.FunctionCall{}); !goja.IsUndefined(code) {
-		t.Fatalf("expected undefined code, got %v", code)
-	}
-	if ok := runtime.authSetCode(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(map[string]interface{}{"code": "abc", "access_token": "access", "refresh_token": "refresh", "expires_in": float64(60)})}}); !ok.ToBoolean() {
-		t.Fatal("authSetCode returned false")
-	}
-	if code := runtime.authGetCode(goja.FunctionCall{}).String(); code != "abc" {
-		t.Fatalf("code = %q", code)
-	}
-	if !runtime.authIsAuthenticated(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("expected authenticated runtime")
-	}
-	tokens := runtime.authGetTokens(goja.FunctionCall{}).Export().(map[string]interface{})
-	if tokens["access_token"] != "access" {
-		t.Fatalf("tokens = %#v", tokens)
-	}
-
-	pkce := runtime.authGeneratePKCE(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(float64(50))}}).Export().(map[string]interface{})
-	if pkce["method"] != "S256" || pkce["verifier"] == "" || pkce["challenge"] == "" {
-		t.Fatalf("pkce = %#v", pkce)
-	}
-	if current := runtime.authGetPKCE(goja.FunctionCall{}).Export().(map[string]interface{}); current["verifier"] == "" {
-		t.Fatalf("current pkce = %#v", current)
-	}
-	oauthConfig := map[string]interface{}{
-		"authUrl":     "https://auth.example.com/oauth",
-		"clientId":    "client",
-		"redirectUri": "app://callback",
-		"scope":       "read",
-		"extraParams": map[string]interface{}{"prompt": "login"},
-	}
-	oauth := runtime.authStartOAuthWithPKCE(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(oauthConfig)}}).Export().(map[string]interface{})
-	if oauth["success"] != true || !strings.Contains(oauth["authUrl"].(string), "code_challenge") {
-		t.Fatalf("oauth = %#v", oauth)
-	}
-	tokenConfig := map[string]interface{}{
-		"tokenUrl":    "https://token.example.com/token",
-		"clientId":    "client",
-		"redirectUri": "app://callback",
-		"code":        "abc",
-	}
-	token := runtime.authExchangeCodeWithPKCE(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(tokenConfig)}}).Export().(map[string]interface{})
-	if token["success"] != true || token["access_token"] != "access" {
-		t.Fatalf("token = %#v", token)
-	}
-
-	runtime.registerTextEncoderDecoder(vm)
-	runtime.registerURLClass(vm)
-	runtime.registerJSONGlobal(vm)
-	vm.Set("fetch", func(call goja.FunctionCall) goja.Value {
-		return runtime.fetchPolyfill(call)
-	})
-	vm.Set("atob", func(call goja.FunctionCall) goja.Value {
-		return runtime.atobPolyfill(call)
-	})
-	vm.Set("btoa", func(call goja.FunctionCall) goja.Value {
-		return runtime.btoaPolyfill(call)
-	})
-
-	value, err := vm.RunString(`
-		var encoded = btoa("hello");
-		var decoded = atob(encoded);
-		var te = new TextEncoder();
-		var bytes = te.encode("hi");
-		var into = te.encodeInto("hi", []);
-		var td = new TextDecoder();
-		var text = td.decode(bytes);
-		var url = new URL("/path?a=1&a=2#frag", "https://api.example.com/base");
-		var params = new URLSearchParams("?x=1");
-		params.append("x", "2");
-		params.set("y", "3");
-		var response = fetch("https://api.example.com/data", {method: "POST", body: {q: "x"}, headers: {"X-Client": "test"}});
-		JSON.stringify({
-			encoded: encoded,
-			decoded: decoded,
-			text: text,
-			read: into.read,
-			host: url.hostname,
-			first: url.searchParams.get("a"),
-			all: url.searchParams.getAll("a").length,
-			params: params.toString(),
-			ok: response.ok,
-			status: response.status,
-			jsonOk: response.json().ok,
-			bufferLen: response.arrayBuffer().length
-		});
-	`)
-	if err != nil {
-		t.Fatalf("polyfill script: %v", err)
-	}
-	var result map[string]interface{}
-	if err := json.Unmarshal([]byte(value.String()), &result); err != nil {
-		t.Fatalf("decode polyfill result: %v", err)
-	}
-	if result["decoded"] != "hello" || result["host"] != "api.example.com" || result["ok"] != true {
-		t.Fatalf("polyfill result = %#v", result)
-	}
-
-	blocked := runtime.fetchPolyfill(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("https://blocked.example.com")}}).ToObject(vm)
-	if blocked.Get("ok").ToBoolean() {
-		t.Fatal("expected blocked fetch")
-	}
-	runtime.authClear(goja.FunctionCall{})
-	if runtime.authIsAuthenticated(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("expected auth cleared")
-	}
-}
-
-func TestExtensionStoreSettingsAndRuntimeStorage(t *testing.T) {
-	dir := t.TempDir()
-	store := &extensionStore{
-		registryURL: "https://registry.example.com/registry.json",
-		cacheDir:    dir,
-		cacheTTL:    time.Hour,
-		cache: &storeRegistry{
-			Version:   1,
-			UpdatedAt: "2026-05-04",
-			Extensions: []storeExtension{
-				{
-					ID:               "coverage-ext",
-					Name:             "coverage-ext",
-					DisplayNameAlt:   "Coverage Extension",
-					Version:          "2.0.0",
-					Description:      "Metadata and lyrics provider",
-					DownloadURLAlt:   "https://registry.example.com/coverage.spotiflac-ext",
-					IconURLAlt:       "https://registry.example.com/icon.png",
-					Category:         CategoryMetadata,
-					Tags:             []string{"metadata", "lyrics"},
-					Downloads:        10,
-					UpdatedAt:        "2026-05-04",
-					MinAppVersionAlt: "4.5.0",
-				},
-				{
-					ID:          "utility-ext",
-					Name:        "utility-ext",
-					Version:     "1.0.0",
-					Description: "Utility",
-					DownloadURL: "https://registry.example.com/utility.spotiflac-ext",
-					Category:    CategoryUtility,
-					UpdatedAt:   "2026-05-04",
-				},
-			},
-		},
-		cacheTime: time.Now(),
-	}
-	store.saveDiskCache()
-	loadedStore := &extensionStore{cacheDir: dir}
-	loadedStore.loadDiskCache()
-	if loadedStore.cache == nil || len(loadedStore.cache.Extensions) != 2 {
-		t.Fatalf("loaded cache = %#v", loadedStore.cache)
-	}
-	if got := store.getRegistryURL(); got != "https://registry.example.com/registry.json" {
-		t.Fatalf("registry URL = %q", got)
-	}
-	store.setRegistryURL("https://registry.example.com/new.json")
-	if store.cache != nil {
-		t.Fatal("expected cache reset after registry URL change")
-	}
-	store.cache = loadedStore.cache
-	store.cacheTime = time.Now()
-
-	manager := getExtensionManager()
-	manager.mu.Lock()
-	if manager.extensions == nil {
-		manager.extensions = map[string]*loadedExtension{}
-	}
-	manager.extensions["coverage-ext"] = &loadedExtension{
-		ID: "coverage-ext",
-		Manifest: &ExtensionManifest{
-			Name:        "coverage-ext",
-			DisplayName: "Coverage Extension",
-			Version:     "1.0.0",
-			Description: "Installed",
-			Types:       []ExtensionType{ExtensionTypeMetadataProvider},
-		},
-		Enabled: true,
-	}
-	manager.mu.Unlock()
-	defer func() {
-		manager.mu.Lock()
-		delete(manager.extensions, "coverage-ext")
-		manager.mu.Unlock()
-	}()
-
-	extensions, err := store.getExtensionsWithStatus(false)
-	if err != nil {
-		t.Fatalf("getExtensionsWithStatus: %v", err)
-	}
-	if len(extensions) != 2 || !extensions[0].IsInstalled || !extensions[0].HasUpdate {
-		t.Fatalf("extensions = %#v", extensions)
-	}
-	found, err := store.searchExtensions("lyrics", CategoryMetadata)
-	if err != nil || len(found) != 1 || found[0].ID != "coverage-ext" {
-		t.Fatalf("search = %#v/%v", found, err)
-	}
-	all, err := store.searchExtensions("", "")
-	if err != nil || len(all) != 2 {
-		t.Fatalf("all search = %#v/%v", all, err)
-	}
-	if cats := store.getCategories(); len(cats) != 5 {
-		t.Fatalf("categories = %#v", cats)
-	}
-	if !containsIgnoreCase("Hello Metadata", "metadata") || findSubstring("abcdef", "cd") != 2 || containsStr("abc", "z") {
-		t.Fatal("string helper mismatch")
-	}
-	if err := requireHTTPSURL("http://example.com", "registry"); err == nil {
-		t.Fatal("expected HTTPS validation error")
-	}
-	if _, err := resolveRegistryURL(""); err == nil {
-		t.Fatal("expected empty registry URL error")
-	}
-	if resolved, err := resolveRegistryURL("http://github.com/owner/repo"); err != nil || !strings.Contains(resolved, "raw.githubusercontent.com/owner/repo") {
-		t.Fatalf("resolved registry = %q/%v", resolved, err)
-	}
-	store.clearCache()
-	if store.cache != nil {
-		t.Fatal("expected cleared store cache")
-	}
-
-	settingsStore := &ExtensionSettingsStore{settings: map[string]map[string]interface{}{}}
-	if err := settingsStore.SetDataDir(filepath.Join(dir, "settings")); err != nil {
-		t.Fatalf("SetDataDir: %v", err)
-	}
-	if err := settingsStore.Set("ext", "quality", "lossless"); err != nil {
-		t.Fatalf("settings Set: %v", err)
-	}
-	if value, err := settingsStore.Get("ext", "quality"); err != nil || value != "lossless" {
-		t.Fatalf("settings Get = %#v/%v", value, err)
-	}
-	if _, err := settingsStore.Get("ext", "missing"); err == nil {
-		t.Fatal("expected missing setting error")
-	}
-	if err := settingsStore.SetAll("ext", map[string]interface{}{"a": float64(1), "_secret": "hidden"}); err != nil {
-		t.Fatalf("settings SetAll: %v", err)
-	}
-	if all := settingsStore.GetAll("ext"); all["a"] != float64(1) {
-		t.Fatalf("settings all = %#v", all)
-	}
-	if err := settingsStore.Remove("ext", "a"); err != nil {
-		t.Fatalf("settings Remove: %v", err)
-	}
-	if err := settingsStore.RemoveAll("ext"); err != nil {
-		t.Fatalf("settings RemoveAll: %v", err)
-	}
-	if jsonText, err := settingsStore.GetAllExtensionSettingsJSON(); err != nil || jsonText == "" {
-		t.Fatalf("settings JSON = %q/%v", jsonText, err)
-	}
-	reloaded := &ExtensionSettingsStore{settings: map[string]map[string]interface{}{}}
-	if err := reloaded.SetDataDir(settingsStore.dataDir); err != nil {
-		t.Fatalf("reload settings: %v", err)
-	}
-
-	vm := goja.New()
-	runtime := &extensionRuntime{
-		extensionID:       "storage-ext",
-		dataDir:           filepath.Join(dir, "runtime"),
-		vm:                vm,
-		storageFlushDelay: time.Hour,
-	}
-	if err := os.MkdirAll(runtime.dataDir, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if got := runtime.storageGet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("missing"), vm.ToValue("fallback")}}).String(); got != "fallback" {
-		t.Fatalf("storage fallback = %q", got)
-	}
-	if ok := runtime.storageSet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("key"), vm.ToValue(map[string]interface{}{"nested": "value"})}}); !ok.ToBoolean() {
-		t.Fatal("storageSet false")
-	}
-	if ok := runtime.storageSet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("key"), vm.ToValue(map[string]interface{}{"nested": "value"})}}); !ok.ToBoolean() {
-		t.Fatal("storageSet equal false")
-	}
-	loaded, err := runtime.loadStorage()
-	if err != nil || loaded["key"] == nil {
-		t.Fatalf("loadStorage = %#v/%v", loaded, err)
-	}
-	if err := runtime.flushStorageNow(); err != nil {
-		t.Fatalf("flushStorageNow: %v", err)
-	}
-	if ok := runtime.storageRemove(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("key")}}); !ok.ToBoolean() {
-		t.Fatal("storageRemove false")
-	}
-	runtime.closeStorageFlusher()
-	if ok := runtime.storageSet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("after_close"), vm.ToValue("x")}}); ok.ToBoolean() {
-		t.Fatal("expected storageSet false after close")
-	}
-
-	credRuntime := &extensionRuntime{
-		extensionID: "cred-ext",
-		dataDir:     filepath.Join(dir, "creds"),
-		vm:          vm,
-	}
-	if err := os.MkdirAll(credRuntime.dataDir, 0755); err != nil {
-		t.Fatal(err)
-	}
-	if result := credRuntime.credentialsStore(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("token"), vm.ToValue("secret")}}).Export().(map[string]interface{}); result["success"] != true {
-		t.Fatalf("credentialsStore = %#v", result)
-	}
-	if got := credRuntime.credentialsGet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("token")}}).String(); got != "secret" {
-		t.Fatalf("credential = %q", got)
-	}
-	if !credRuntime.credentialsHas(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("token")}}).ToBoolean() {
-		t.Fatal("expected credential")
-	}
-	if ok := credRuntime.credentialsRemove(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("token")}}); !ok.ToBoolean() {
-		t.Fatal("credentialsRemove false")
-	}
-	if credRuntime.credentialsHas(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("token")}}).ToBoolean() {
-		t.Fatal("expected credential removed")
-	}
-	key, err := credRuntime.getEncryptionKey()
-	if err != nil {
-		t.Fatalf("getEncryptionKey: %v", err)
-	}
-	encrypted, err := encryptAES([]byte("plain"), key)
-	if err != nil {
-		t.Fatalf("encryptAES: %v", err)
-	}
-	decrypted, err := decryptAES(encrypted, key)
-	if err != nil || string(decrypted) != "plain" {
-		t.Fatalf("decryptAES = %q/%v", decrypted, err)
-	}
-	if _, err := decryptAES([]byte("short"), key); err == nil {
-		t.Fatal("expected short ciphertext error")
-	}
-}
-
-func TestExtensionRuntimeHTTPMatchingAndMetadataHelpers(t *testing.T) {
-	vm := goja.New()
-	jar, _ := newSimpleCookieJar()
-	runtime := &extensionRuntime{
-		extensionID: "http-ext",
-		manifest: &ExtensionManifest{
-			Name:        "http-ext",
-			Description: "HTTP extension",
-			Version:     "1.0.0",
-			Permissions: ExtensionPermissions{
-				Network: []string{"api.example.com"},
-			},
-		},
-		vm:        vm,
-		cookieJar: jar,
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			var body []byte
-			if req.Body != nil {
-				body, _ = io.ReadAll(req.Body)
-			}
-			header := make(http.Header)
-			header.Set("X-Method", req.Method)
-			if req.URL.Path == "/huge" {
-				return &http.Response{StatusCode: 200, Header: header, Body: io.NopCloser(io.LimitReader(strings.NewReader(strings.Repeat("x", maxExtensionHTTPResponseBytes+2)), maxExtensionHTTPResponseBytes+2)), Request: req}, nil
-			}
-			return &http.Response{
-				StatusCode: 201,
-				Header:     header,
-				Body:       io.NopCloser(strings.NewReader(req.Method + ":" + string(body))),
-				Request:    req,
-			}, nil
-		})},
-	}
-
-	if err := runtime.validateDomain("https://api.example.com/path"); err != nil {
-		t.Fatalf("validateDomain allowed: %v", err)
-	}
-	for _, rawURL := range []string{"notaurl", "http://api.example.com", "https://user:pass@api.example.com", "https://127.0.0.1/x", "https://blocked.example.com/x"} {
-		if err := runtime.validateDomain(rawURL); err == nil {
-			t.Fatalf("expected domain validation error for %s", rawURL)
-		}
-	}
-	if got := runtime.httpGet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("https://api.example.com/get"), vm.ToValue(map[string]interface{}{"X-Test": "yes"})}}).Export().(map[string]interface{}); got["status"] != 201 || !strings.Contains(got["body"].(string), "GET") {
-		t.Fatalf("httpGet = %#v", got)
-	}
-	if got := runtime.httpPost(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("https://api.example.com/post"), vm.ToValue(map[string]interface{}{"a": "b"})}}).Export().(map[string]interface{}); !strings.Contains(got["body"].(string), "POST") {
-		t.Fatalf("httpPost = %#v", got)
-	}
-	requestOptions := map[string]interface{}{"method": "patch", "body": []interface{}{"x"}, "headers": map[string]interface{}{"X-Req": "1"}}
-	if got := runtime.httpRequest(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("https://api.example.com/request"), vm.ToValue(requestOptions)}}).Export().(map[string]interface{}); !strings.Contains(got["body"].(string), "PATCH") {
-		t.Fatalf("httpRequest = %#v", got)
-	}
-	for _, method := range []struct {
-		name string
-		call func(goja.FunctionCall) goja.Value
-		args []goja.Value
-	}{
-		{name: "PUT", call: runtime.httpPut, args: []goja.Value{vm.ToValue("https://api.example.com/put"), vm.ToValue("body")}},
-		{name: "DELETE", call: runtime.httpDelete, args: []goja.Value{vm.ToValue("https://api.example.com/delete"), vm.ToValue(map[string]interface{}{"X-Delete": "1"})}},
-		{name: "PATCH", call: runtime.httpPatch, args: []goja.Value{vm.ToValue("https://api.example.com/patch"), vm.ToValue(map[string]interface{}{"p": "q"})}},
-	} {
-		if got := method.call(goja.FunctionCall{Arguments: method.args}).Export().(map[string]interface{}); !strings.Contains(got["body"].(string), method.name) {
-			t.Fatalf("%s = %#v", method.name, got)
-		}
-	}
-	if got := runtime.httpGet(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("https://api.example.com/huge")}}).Export().(map[string]interface{}); !strings.Contains(got["error"].(string), "exceeds") {
-		t.Fatalf("huge response = %#v", got)
-	}
-	if !runtime.httpClearCookies(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("expected cookies cleared")
-	}
-
-	if runtime.matchingCompareStrings(goja.FunctionCall{}).ToFloat() != 0 {
-		t.Fatal("missing string compare args should be zero")
-	}
-	if runtime.matchingCompareStrings(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("Song"), vm.ToValue("song")}}).ToFloat() != 1 {
-		t.Fatal("expected exact string similarity")
-	}
-	if runtime.matchingCompareDuration(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(180000), vm.ToValue(182000)}}).ToBoolean() != true {
-		t.Fatal("expected duration match")
-	}
-	if runtime.matchingNormalizeString(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("Song (Remastered) feat. Guest!")}}).String() != "song" {
-		t.Fatalf("normalized = %q", runtime.matchingNormalizeString(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("Song (Remastered) feat. Guest!")}}).String())
-	}
-
-	if formatMusicBrainzGenre([]musicBrainzTag{{Count: 1, Name: "rock"}, {Count: 5, Name: "electronic"}, {Count: 10, Name: "rock"}}) != "Electronic" {
-		t.Fatal("unexpected genre selection")
-	}
-	credits := []musicBrainzArtistCredit{{Name: "A", JoinPhrase: " & "}, {Name: "B"}}
-	if formatMusicBrainzArtistCredit(credits) != "A & B" {
-		t.Fatal("artist credit format mismatch")
-	}
-	releases := []musicBrainzRelease{
-		{Title: "Other", ArtistCredit: []musicBrainzArtistCredit{{Name: "Fallback"}}},
-		{Title: "Album", ArtistCredit: credits},
-	}
-	if selectMusicBrainzAlbumArtist(releases, "Album") != "A & B" || selectMusicBrainzAlbumArtist(releases, "") != "Fallback" {
-		t.Fatal("album artist selection mismatch")
-	}
-}
-
-func TestExtensionRuntimeFileAPIs(t *testing.T) {
-	vm := goja.New()
-	dir := t.TempDir()
-	SetAllowedDownloadDirs(nil)
-	defer SetAllowedDownloadDirs(nil)
-
-	fileBody := "chunk"
-	runtime := &extensionRuntime{
-		extensionID: "file-ext",
-		manifest: &ExtensionManifest{
-			Name:        "file-ext",
-			Description: "File extension",
-			Version:     "1.0.0",
-			Permissions: ExtensionPermissions{
-				File:    true,
-				Network: []string{"files.example.com"},
-			},
-		},
-		dataDir: dir,
-		vm:      vm,
-		httpClient: &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-			if req.Header.Get("Range") == "" {
-				body := "downloaded"
-				return &http.Response{
-					StatusCode:    200,
-					Header:        make(http.Header),
-					Body:          io.NopCloser(strings.NewReader(body)),
-					ContentLength: int64(len(body)),
-					Request:       req,
-				}, nil
-			}
-			rangeHeader := req.Header.Get("Range")
-			start, end := 0, len(fileBody)-1
-			if _, err := fmt.Sscanf(rangeHeader, "bytes=%d-%d", &start, &end); err != nil {
-				start, end = 0, 1
-			}
-			if start < 0 {
-				start = 0
-			}
-			if end >= len(fileBody) {
-				end = len(fileBody) - 1
-			}
-			if start > len(fileBody) {
-				start = len(fileBody)
-			}
-			body := fileBody[start : end+1]
-			header := http.Header{"Content-Range": []string{fmt.Sprintf("bytes %d-%d/%d", start, end, len(fileBody))}}
-			return &http.Response{StatusCode: 206, Header: header, Body: io.NopCloser(strings.NewReader(body)), Request: req}, nil
-		})},
-	}
-	runtime.downloadClient = runtime.httpClient
-
-	if _, err := (&extensionRuntime{manifest: &ExtensionManifest{}}).validatePath("x"); err == nil {
-		t.Fatal("expected file permission error")
-	}
-	if _, err := runtime.validatePath("../escape.txt"); err == nil {
-		t.Fatal("expected sandbox escape error")
-	}
-	AddAllowedDownloadDir(dir)
-	absolutePath := filepath.Join(dir, "allowed.txt")
-	if got, err := runtime.validatePath(absolutePath); err != nil || got != absolutePath {
-		t.Fatalf("absolute validatePath = %q/%v", got, err)
-	}
-
-	write := runtime.fileWrite(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/a.txt"), vm.ToValue("hello")}}).Export().(map[string]interface{})
-	if write["success"] != true {
-		t.Fatalf("fileWrite = %#v", write)
-	}
-	if !runtime.fileExists(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/a.txt")}}).ToBoolean() {
-		t.Fatal("expected written file to exist")
-	}
-	read := runtime.fileRead(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/a.txt")}}).Export().(map[string]interface{})
-	if read["data"] != "hello" {
-		t.Fatalf("fileRead = %#v", read)
-	}
-
-	writeBytes := runtime.fileWriteBytes(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("nested/bytes.bin"),
-		vm.ToValue("4869"),
-		vm.ToValue(map[string]interface{}{"encoding": "hex", "truncate": true}),
-	}}).Export().(map[string]interface{})
-	if writeBytes["success"] != true {
-		t.Fatalf("fileWriteBytes = %#v", writeBytes)
-	}
-	appendBytes := runtime.fileWriteBytes(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("nested/bytes.bin"),
-		vm.ToValue([]interface{}{float64('!')}),
-		vm.ToValue(map[string]interface{}{"append": true}),
-	}}).Export().(map[string]interface{})
-	if appendBytes["success"] != true {
-		t.Fatalf("append fileWriteBytes = %#v", appendBytes)
-	}
-	readBytes := runtime.fileReadBytes(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("nested/bytes.bin"),
-		vm.ToValue(map[string]interface{}{"encoding": "text", "offset": float64(1), "length": float64(2)}),
-	}}).Export().(map[string]interface{})
-	if readBytes["data"] != "i!" || readBytes["bytes_read"] != 2 {
-		t.Fatalf("fileReadBytes = %#v", readBytes)
-	}
-	if bad := runtime.fileWriteBytes(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("nested/bad.bin"),
-		vm.ToValue("x"),
-		vm.ToValue(map[string]interface{}{"append": true, "offset": float64(1)}),
-	}}).Export().(map[string]interface{}); bad["success"] != false {
-		t.Fatalf("expected append+offset failure, got %#v", bad)
-	}
-	if bad := runtime.fileReadBytes(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("nested/bytes.bin"),
-		vm.ToValue(map[string]interface{}{"encoding": "bad"}),
-	}}).Export().(map[string]interface{}); bad["success"] != false {
-		t.Fatalf("expected bad encoding failure, got %#v", bad)
-	}
-
-	copyResult := runtime.fileCopy(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/bytes.bin"), vm.ToValue("nested/copy.bin")}}).Export().(map[string]interface{})
-	if copyResult["success"] != true {
-		t.Fatalf("fileCopy = %#v", copyResult)
-	}
-	moveResult := runtime.fileMove(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/copy.bin"), vm.ToValue("nested/moved.bin")}}).Export().(map[string]interface{})
-	if moveResult["success"] != true {
-		t.Fatalf("fileMove = %#v", moveResult)
-	}
-	sizeResult := runtime.fileGetSize(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/moved.bin")}}).Export().(map[string]interface{})
-	if sizeResult["success"] != true || sizeResult["size"] != int64(3) {
-		t.Fatalf("fileGetSize = %#v", sizeResult)
-	}
-	deleteResult := runtime.fileDelete(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("nested/moved.bin")}}).Export().(map[string]interface{})
-	if deleteResult["success"] != true {
-		t.Fatalf("fileDelete = %#v", deleteResult)
-	}
-
-	download := runtime.fileDownload(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("https://files.example.com/file"),
-		vm.ToValue("downloads/file.bin"),
-	}}).Export().(map[string]interface{})
-	if download["success"] != true {
-		t.Fatalf("fileDownload = %#v", download)
-	}
-	if data, err := os.ReadFile(filepath.Join(dir, "downloads/file.bin")); err != nil || string(data) != "downloaded" {
-		t.Fatalf("downloaded data = %q/%v", data, err)
-	}
-
-	chunked := runtime.fileDownload(goja.FunctionCall{Arguments: []goja.Value{
-		vm.ToValue("https://files.example.com/chunk"),
-		vm.ToValue("downloads/chunk.bin"),
-		vm.ToValue(map[string]interface{}{"chunked": float64(2), "headers": map[string]interface{}{"X-Test": "yes"}}),
-	}}).Export().(map[string]interface{})
-	if chunked["success"] != true {
-		t.Fatalf("chunked fileDownload = %#v", chunked)
-	}
-	if data, err := os.ReadFile(filepath.Join(dir, "downloads/chunk.bin")); err != nil || string(data) != fileBody {
-		t.Fatalf("chunked data = %q/%v", data, err)
-	}
-
-	if missing := runtime.fileDownload(goja.FunctionCall{}).Export().(map[string]interface{}); missing["success"] != false {
-		t.Fatalf("expected missing download args error, got %#v", missing)
-	}
-}
-
-func TestExtensionRuntimeUtilityAPIs(t *testing.T) {
-	vm := goja.New()
-	runtime := &extensionRuntime{extensionID: "utils-ext", vm: vm}
-
-	if runtime.sha256Hash(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("abc")}}).String() == "" {
-		t.Fatal("expected sha256")
-	}
-	if runtime.hmacSHA256(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("msg"), vm.ToValue("key")}}).String() == "" {
-		t.Fatal("expected hmac sha256")
-	}
-	if runtime.hmacSHA256Base64(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("msg"), vm.ToValue("key")}}).String() == "" {
-		t.Fatal("expected hmac sha256 base64")
-	}
-	if value := runtime.hmacSHA1(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue([]interface{}{float64(1), float64(2)}), vm.ToValue([]interface{}{float64(3)})}}); len(value.Export().([]interface{})) == 0 {
-		t.Fatal("expected hmac sha1 bytes")
-	}
-	if !goja.IsUndefined(runtime.parseJSON(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(`{bad`)}})) {
-		t.Fatal("expected invalid JSON to return undefined")
-	}
-	parsed := runtime.parseJSON(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(`{"ok":true}`)}}).Export().(map[string]interface{})
-	if parsed["ok"] != true {
-		t.Fatalf("parseJSON = %#v", parsed)
-	}
-	if text := runtime.stringifyJSON(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(map[string]interface{}{"ok": true})}}).String(); !strings.Contains(text, "ok") {
-		t.Fatalf("stringifyJSON = %q", text)
-	}
-	encrypted := runtime.cryptoEncrypt(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("plain"), vm.ToValue("secret")}}).Export().(map[string]interface{})
-	if encrypted["success"] != true || encrypted["data"] == "" {
-		t.Fatalf("cryptoEncrypt = %#v", encrypted)
-	}
-	decrypted := runtime.cryptoDecrypt(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(encrypted["data"]), vm.ToValue("secret")}}).Export().(map[string]interface{})
-	if decrypted["success"] != true || decrypted["data"] != "plain" {
-		t.Fatalf("cryptoDecrypt = %#v", decrypted)
-	}
-	if bad := runtime.cryptoDecrypt(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("bad"), vm.ToValue("secret")}}).Export().(map[string]interface{}); bad["success"] != false {
-		t.Fatalf("expected bad decrypt failure, got %#v", bad)
-	}
-	key := runtime.cryptoGenerateKey(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(float64(8))}}).Export().(map[string]interface{})
-	if key["success"] != true || key["key"] == "" || key["hex"] == "" {
-		t.Fatalf("cryptoGenerateKey = %#v", key)
-	}
-	if runtime.randomUserAgent(goja.FunctionCall{}).String() == "" || runtime.appUserAgent(goja.FunctionCall{}).String() == "" {
-		t.Fatal("expected user agents")
-	}
-	SetAppVersion("9.9.9")
-	if runtime.appVersion(goja.FunctionCall{}).String() != "9.9.9" {
-		t.Fatal("appVersion mismatch")
-	}
-	if !runtime.sleep(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(float64(0))}}).ToBoolean() {
-		t.Fatal("zero sleep should succeed")
-	}
-
-	itemID := "utils-item"
-	runtime.setActiveDownloadItemID(itemID)
-	initDownloadCancel(itemID)
-	if runtime.isDownloadCancelled(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("item should not be cancelled yet")
-	}
-	runtime.setDownloadStatus(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue(itemProgressStatusDownloading)}})
-	cancelDownload(itemID)
-	if !runtime.isDownloadCancelled(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("item should be cancelled")
-	}
-	clearDownloadCancel(itemID)
-	runtime.clearActiveDownloadItemID()
-
-	requestID := "utils-request"
-	runtime.setActiveRequestID(requestID)
-	initExtensionRequestCancel(requestID)
-	if runtime.isRequestCancelled(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("request should not be cancelled yet")
-	}
-	cancelExtensionRequest(requestID)
-	if !runtime.isRequestCancelled(goja.FunctionCall{}).ToBoolean() {
-		t.Fatal("request should be cancelled")
-	}
-	clearExtensionRequestCancel(requestID)
-	runtime.clearActiveRequestID()
-
-	if msg := runtime.formatLogArgs([]goja.Value{vm.ToValue("a"), vm.ToValue(1)}); msg != "a 1" {
-		t.Fatalf("formatLogArgs = %q", msg)
-	}
-	runtime.logDebug(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("debug")}})
-	runtime.logInfo(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("info")}})
-	runtime.logWarn(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("warn")}})
-	runtime.logError(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("error")}})
-	if clean := runtime.sanitizeFilenameWrapper(goja.FunctionCall{Arguments: []goja.Value{vm.ToValue("A/B?")}}).String(); strings.ContainsAny(clean, "/?") {
-		t.Fatalf("sanitize wrapper = %q", clean)
-	}
-}

go_backend/extension_runtime_utils.go

@@ -16,7 +16,7 @@ import (
 	"github.com/dop251/goja"
 )
 
-func (r *extensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -24,7 +24,7 @@ func (r *extensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-func (r *extensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -36,7 +36,7 @@ func (r *extensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-func (r *extensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -45,7 +45,7 @@ func (r *extensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-func (r *extensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -54,7 +54,7 @@ func (r *extensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-func (r *extensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
 	}
@@ -66,7 +66,7 @@ func (r *extensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(mac.Sum(nil)))
 }
 
-func (r *extensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
 	}
@@ -78,7 +78,7 @@ func (r *extensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString(mac.Sum(nil)))
 }
 
-func (r *extensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue([]byte{})
 	}
@@ -130,7 +130,7 @@ func (r *extensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(jsArray)
 }
 
-func (r *extensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
 	}
@@ -145,7 +145,7 @@ func (r *extensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(result)
 }
 
-func (r *extensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -160,7 +160,7 @@ func (r *extensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(data))
 }
 
-func (r *extensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -187,7 +187,7 @@ func (r *extensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -222,7 +222,7 @@ func (r *extensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-func (r *extensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
 	length := 32
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok {
@@ -245,125 +245,35 @@ func (r *extensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value
 	})
 }
 
-func (r *extensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(getRandomUserAgent())
 }
 
-func (r *extensionRuntime) appVersion(call goja.FunctionCall) goja.Value {
-	return r.vm.ToValue(GetAppVersion())
-}
-
-func (r *extensionRuntime) appUserAgent(call goja.FunctionCall) goja.Value {
-	return r.vm.ToValue(appUserAgent())
-}
-
-func (r *extensionRuntime) sleep(call goja.FunctionCall) goja.Value {
-	if len(call.Arguments) < 1 {
-		return r.vm.ToValue(true)
-	}
-
-	sleepMs := 0
-	switch value := call.Arguments[0].Export().(type) {
-	case int64:
-		sleepMs = int(value)
-	case int32:
-		sleepMs = int(value)
-	case int:
-		sleepMs = value
-	case float64:
-		sleepMs = int(value)
-	default:
-		sleepMs = 0
-	}
-
-	if sleepMs <= 0 {
-		return r.vm.ToValue(true)
-	}
-	if sleepMs > 5*60*1000 {
-		sleepMs = 5 * 60 * 1000
-	}
-
-	itemID := r.getActiveDownloadItemID()
-	deadline := time.Now().Add(time.Duration(sleepMs) * time.Millisecond)
-
-	for {
-		if itemID != "" && isDownloadCancelled(itemID) {
-			return r.vm.ToValue(false)
-		}
-
-		remaining := time.Until(deadline)
-		if remaining <= 0 {
-			return r.vm.ToValue(true)
-		}
-
-		step := 100 * time.Millisecond
-		if remaining < step {
-			step = remaining
-		}
-		time.Sleep(step)
-	}
-}
-
-func (r *extensionRuntime) isDownloadCancelled(call goja.FunctionCall) goja.Value {
-	itemID := r.getActiveDownloadItemID()
-	if itemID == "" {
-		return r.vm.ToValue(false)
-	}
-	return r.vm.ToValue(isDownloadCancelled(itemID))
-}
-
-func (r *extensionRuntime) isRequestCancelled(call goja.FunctionCall) goja.Value {
-	requestID := r.getActiveRequestID()
-	if requestID == "" {
-		return r.vm.ToValue(false)
-	}
-	return r.vm.ToValue(isExtensionRequestCancelled(requestID))
-}
-
-func (r *extensionRuntime) setDownloadStatus(call goja.FunctionCall) goja.Value {
-	itemID := r.getActiveDownloadItemID()
-	if itemID == "" || len(call.Arguments) < 1 {
-		return goja.Undefined()
-	}
-
-	status := strings.ToLower(strings.TrimSpace(call.Arguments[0].String()))
-	switch status {
-	case itemProgressStatusPreparing:
-		SetItemPreparing(itemID)
-	case itemProgressStatusDownloading:
-		SetItemDownloading(itemID)
-	case itemProgressStatusFinalizing:
-		SetItemFinalizing(itemID)
-	}
-
-	return goja.Undefined()
-}
-
-func (r *extensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:DEBUG] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *extensionRuntime) logInfo(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) logInfo(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:INFO] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *extensionRuntime) logWarn(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) logWarn(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:WARN] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *extensionRuntime) logError(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) logError(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:ERROR] %s\n", r.extensionID, msg)
 	return goja.Undefined()
 }
 
-func (r *extensionRuntime) formatLogArgs(args []goja.Value) string {
+func (r *ExtensionRuntime) formatLogArgs(args []goja.Value) string {
 	parts := make([]string, len(args))
 	for i, arg := range args {
 		parts[i] = fmt.Sprintf("%v", arg.Export())
@@ -371,7 +281,7 @@ func (r *extensionRuntime) formatLogArgs(args []goja.Value) string {
 	return strings.Join(parts, " ")
 }
 
-func (r *extensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
+func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
 	}
@@ -379,7 +289,7 @@ func (r *extensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.
 	return r.vm.ToValue(sanitizeFilename(input))
 }
 
-func (r *extensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
+func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 	gobackendObj := vm.Get("gobackend")
 	if gobackendObj == nil || goja.IsUndefined(gobackendObj) {
 		gobackendObj = vm.NewObject()
@@ -414,82 +324,6 @@ func (r *extensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 			"bitDepth":     quality.BitDepth,
 			"sampleRate":   quality.SampleRate,
 			"totalSamples": quality.TotalSamples,
-			"duration":     quality.Duration,
-		})
-	})
-
-	obj.Set("getLyricsLRC", func(call goja.FunctionCall) goja.Value {
-		if len(call.Arguments) < 3 {
-			return vm.ToValue(map[string]interface{}{
-				"error": "spotifyID, trackName, and artistName are required",
-			})
-		}
-
-		spotifyID := strings.TrimSpace(call.Arguments[0].String())
-		trackName := strings.TrimSpace(call.Arguments[1].String())
-		artistName := strings.TrimSpace(call.Arguments[2].String())
-		filePath := ""
-		if len(call.Arguments) > 3 && !goja.IsUndefined(call.Arguments[3]) && !goja.IsNull(call.Arguments[3]) {
-			filePath = strings.TrimSpace(call.Arguments[3].String())
-		}
-		var durationMs int64
-		if len(call.Arguments) > 4 && !goja.IsUndefined(call.Arguments[4]) && !goja.IsNull(call.Arguments[4]) {
-			durationMs = call.Arguments[4].ToInteger()
-		}
-
-		lyrics, err := GetLyricsLRC(spotifyID, trackName, artistName, filePath, durationMs)
-		if err != nil {
-			return vm.ToValue(map[string]interface{}{
-				"error": err.Error(),
-			})
-		}
-
-		return vm.ToValue(map[string]interface{}{
-			"lyrics": lyrics,
-		})
-	})
-
-	obj.Set("checkISRCExists", func(call goja.FunctionCall) goja.Value {
-		if len(call.Arguments) < 2 {
-			return vm.ToValue(map[string]interface{}{
-				"error": "outputDir and isrc are required",
-			})
-		}
-
-		outputDir := strings.TrimSpace(call.Arguments[0].String())
-		isrc := strings.TrimSpace(call.Arguments[1].String())
-		if outputDir == "" || isrc == "" {
-			return vm.ToValue(map[string]interface{}{
-				"error": "outputDir and isrc are required",
-			})
-		}
-
-		filePath, exists := checkISRCExistsInternal(outputDir, isrc)
-		return vm.ToValue(map[string]interface{}{
-			"exists":   exists,
-			"filePath": filePath,
-		})
-	})
-
-	obj.Set("addToISRCIndex", func(call goja.FunctionCall) goja.Value {
-		if len(call.Arguments) < 3 {
-			return vm.ToValue(map[string]interface{}{
-				"error": "outputDir, isrc, and filePath are required",
-			})
-		}
-
-		outputDir := strings.TrimSpace(call.Arguments[0].String())
-		isrc := strings.TrimSpace(call.Arguments[1].String())
-		filePath := strings.TrimSpace(call.Arguments[2].String())
-		if outputDir == "" || isrc == "" || filePath == "" {
-			return vm.ToValue(map[string]interface{}{
-				"error": "outputDir, isrc, and filePath are required",
-			})
-		}
-
-		AddToISRCIndex(outputDir, isrc, filePath)
-		return vm.ToValue(map[string]interface{}{
-			"success": true,
 		})
 	})
 

go_backend/extension_store.go

@@ -26,6 +26,7 @@ type storeExtension struct {
 	Name             string   `json:"name"`
 	DisplayName      string   `json:"display_name,omitempty"`
 	Version          string   `json:"version"`
+	Author           string   `json:"author"`
 	Description      string   `json:"description"`
 	DownloadURL      string   `json:"download_url,omitempty"`
 	IconURL          string   `json:"icon_url,omitempty"`
@@ -82,6 +83,7 @@ type storeExtensionResponse struct {
 	Name             string   `json:"name"`
 	DisplayName      string   `json:"display_name"`
 	Version          string   `json:"version"`
+	Author           string   `json:"author"`
 	Description      string   `json:"description"`
 	DownloadURL      string   `json:"download_url"`
 	IconURL          string   `json:"icon_url,omitempty"`
@@ -101,6 +103,7 @@ func (e *storeExtension) toResponse() storeExtensionResponse {
 		Name:          e.Name,
 		DisplayName:   e.getDisplayName(),
 		Version:       e.Version,
+		Author:        e.Author,
 		Description:   e.Description,
 		DownloadURL:   e.getDownloadURL(),
 		IconURL:       e.getIconURL(),
@@ -142,7 +145,7 @@ func initExtensionStore(cacheDir string) *extensionStore {
 
 	if globalExtensionStore == nil {
 		globalExtensionStore = &extensionStore{
-			registryURL: "",
+			registryURL: "", // No default - user must provide a registry URL
 			cacheDir:    cacheDir,
 			cacheTTL:    cacheTTL,
 		}
@@ -151,6 +154,8 @@ func initExtensionStore(cacheDir string) *extensionStore {
 	return globalExtensionStore
 }
 
+// SetRegistryURL updates the registry URL and clears the in-memory cache
+// so the next fetch will use the new URL. Disk cache is also cleared.
 func (s *extensionStore) setRegistryURL(registryURL string) {
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()
@@ -163,6 +168,7 @@ func (s *extensionStore) setRegistryURL(registryURL string) {
 	s.cache = nil
 	s.cacheTime = time.Time{}
 
+	// Clear disk cache since it's from a different registry
 	if s.cacheDir != "" {
 		cachePath := filepath.Join(s.cacheDir, cacheFileName)
 		os.Remove(cachePath)
@@ -171,6 +177,7 @@ func (s *extensionStore) setRegistryURL(registryURL string) {
 	LogInfo("ExtensionStore", "Registry URL updated to: %s", registryURL)
 }
 
+// GetRegistryURL returns the currently configured registry URL.
 func (s *extensionStore) getRegistryURL() string {
 	s.cacheMu.RLock()
 	defer s.cacheMu.RUnlock()
@@ -250,17 +257,7 @@ func (s *extensionStore) fetchRegistry(forceRefresh bool) (*storeRegistry, error
 	LogInfo("ExtensionStore", "Fetching registry from %s", s.registryURL)
 
 	client := NewHTTPClientWithTimeout(30 * time.Second)
-	req, err := http.NewRequest(http.MethodGet, s.registryURL, nil)
-	if err != nil {
-		if s.cache != nil {
-			LogWarn("ExtensionStore", "Failed to build registry request, using cached registry: %v", err)
-			return s.cache, nil
-		}
-		return nil, fmt.Errorf("failed to build registry request: %w", err)
-	}
-	req.Header.Set("Cache-Control", "no-cache")
-	req.Header.Set("Pragma", "no-cache")
-	resp, err := client.Do(req)
+	resp, err := client.Get(s.registryURL)
 	if err != nil {
 		if s.cache != nil {
 			LogWarn("ExtensionStore", "Network error, using cached registry: %v", err)
@@ -302,7 +299,7 @@ func (s *extensionStore) getExtensionsWithStatus(forceRefresh bool) ([]storeExte
 		return nil, err
 	}
 
-	manager := getExtensionManager()
+	manager := GetExtensionManager()
 	installed := make(map[string]string) // id -> version
 
 	if manager != nil {
@@ -355,13 +352,7 @@ func (s *extensionStore) downloadExtension(extensionID string, destPath string)
 	LogInfo("ExtensionStore", "Downloading %s from %s", ext.getDisplayName(), ext.getDownloadURL())
 
 	client := NewHTTPClientWithTimeout(5 * time.Minute)
-	req, err := http.NewRequest(http.MethodGet, ext.getDownloadURL(), nil)
-	if err != nil {
-		return fmt.Errorf("failed to build download request: %w", err)
-	}
-	req.Header.Set("Cache-Control", "no-cache")
-	req.Header.Set("Pragma", "no-cache")
-	resp, err := client.Do(req)
+	resp, err := client.Get(ext.getDownloadURL())
 	if err != nil {
 		return fmt.Errorf("failed to download: %w", err)
 	}
@@ -387,22 +378,32 @@ func (s *extensionStore) downloadExtension(extensionID string, destPath string)
 	return nil
 }
 
+// ResolveRegistryURL normalises a user-supplied URL into a direct registry.json URL.
+//
+// Accepted formats:
+//   - https://raw.githubusercontent.com/owner/repo/<branch>/registry.json  → returned as-is
+//   - https://github.com/owner/repo  (with optional trailing path / .git)  → resolved via
+//     the GitHub API to discover the default branch, then converted to the raw URL
+//   - Any other HTTPS URL  → returned as-is (assumed to be a direct link)
 func resolveRegistryURL(input string) (string, error) {
 	input = strings.TrimSpace(input)
 	if input == "" {
 		return "", fmt.Errorf("registry URL is empty")
 	}
 
+	// Already a fully-qualified raw URL – keep it.
 	if strings.Contains(input, "raw.githubusercontent.com") {
 		return input, nil
 	}
 
 	const ghPrefix = "https://github.com/"
 	if !strings.HasPrefix(input, ghPrefix) {
+		// Also accept http:// and upgrade silently.
 		const ghPrefixHTTP = "http://github.com/"
 		if strings.HasPrefix(input, ghPrefixHTTP) {
 			input = "https://github.com/" + input[len(ghPrefixHTTP):]
 		} else {
+			// Not a GitHub URL – return as-is.
 			return input, nil
 		}
 	}
@@ -422,6 +423,8 @@ func resolveRegistryURL(input string) (string, error) {
 	return resolved, nil
 }
 
+// resolveGitHubDefaultBranch calls the GitHub API to discover the repository's
+// default branch.  Falls back to "main" on any error.
 func resolveGitHubDefaultBranch(owner, repo string) string {
 	apiURL := fmt.Sprintf("https://api.github.com/repos/%s/%s", owner, repo)
 	client := NewHTTPClientWithTimeout(10 * time.Second)
@@ -494,7 +497,8 @@ func (s *extensionStore) searchExtensions(query string, category string) ([]stor
 		if query != "" {
 			if !containsIgnoreCase(ext.Name, queryLower) &&
 				!containsIgnoreCase(ext.DisplayName, queryLower) &&
-				!containsIgnoreCase(ext.Description, queryLower) {
+				!containsIgnoreCase(ext.Description, queryLower) &&
+				!containsIgnoreCase(ext.Author, queryLower) {
 				found := false
 				for _, tag := range ext.Tags {
 					if containsIgnoreCase(tag, queryLower) {

go_backend/extension_test.go

@@ -1,12 +1,8 @@
 package gobackend
 
 import (
-	"context"
-	"errors"
-	"net/http"
 	"path/filepath"
 	"testing"
-	"time"
 
 	"github.com/dop251/goja"
 )
@@ -16,6 +12,7 @@ func TestParseManifest_Valid(t *testing.T) {
 		"name": "test-provider",
 		"displayName": "Test Provider",
 		"version": "1.0.0",
+		"author": "Test Author",
 		"description": "A test extension",
 		"type": ["metadata_provider"],
 		"permissions": {
@@ -46,26 +43,10 @@ func TestParseManifest_Valid(t *testing.T) {
 	}
 }
 
-func TestExtensionManifestStopsProviderFallback(t *testing.T) {
-	modernManifest := &ExtensionManifest{StopProviderFallback: true}
-	if !modernManifest.StopsProviderFallback() {
-		t.Fatal("expected stopProviderFallback to stop provider fallback")
-	}
-
-	legacyManifest := &ExtensionManifest{SkipBuiltInFallback: true}
-	if !legacyManifest.StopsProviderFallback() {
-		t.Fatal("expected legacy skipBuiltInFallback to stop provider fallback")
-	}
-
-	defaultManifest := &ExtensionManifest{}
-	if defaultManifest.StopsProviderFallback() {
-		t.Fatal("expected default manifest to allow provider fallback")
-	}
-}
-
 func TestParseManifest_MissingName(t *testing.T) {
 	invalidManifest := `{
 		"version": "1.0.0",
+		"author": "Test Author",
 		"description": "A test extension",
 		"type": ["metadata_provider"]
 	}`
@@ -80,6 +61,7 @@ func TestParseManifest_MissingType(t *testing.T) {
 	invalidManifest := `{
 		"name": "test-provider",
 		"version": "1.0.0",
+		"author": "Test Author",
 		"description": "A test extension"
 	}`
 
@@ -116,7 +98,8 @@ func TestIsDomainAllowed(t *testing.T) {
 }
 
 func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
-	ext := &loadedExtension{
+	// Create a mock extension with limited network permissions
+	ext := &LoadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -127,7 +110,7 @@ func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 
 	if err := runtime.validateDomain("https://api.allowed.com/path"); err != nil {
 		t.Errorf("Expected api.allowed.com to be allowed, got error: %v", err)
@@ -144,21 +127,12 @@ func TestExtensionRuntime_NetworkSandbox(t *testing.T) {
 	if err := runtime.validateDomain("https://notallowed.com/path"); err == nil {
 		t.Error("Expected notallowed.com to be denied")
 	}
-
-	if err := runtime.validateDomain("http://api.allowed.com/path"); err == nil {
-		t.Error("Expected http URL to be denied without allowHttp")
-	}
-
-	ext.Manifest.Permissions.AllowHTTP = true
-	if err := runtime.validateDomain("http://api.allowed.com/path"); err != nil {
-		t.Errorf("Expected http URL to be allowed with allowHttp, got error: %v", err)
-	}
 }
 
 func TestExtensionRuntime_FileSandbox(t *testing.T) {
 	tempDir := t.TempDir()
 
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -169,7 +143,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		DataDir: tempDir,
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 
 	validPath, err := runtime.validatePath("test.txt")
 	if err != nil {
@@ -203,7 +177,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		t.Error("Expected absolute path to be blocked")
 	}
 
-	extNoFile := &loadedExtension{
+	extNoFile := &LoadedExtension{
 		ID: "test-ext-no-file",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext-no-file",
@@ -213,7 +187,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 		},
 		DataDir: tempDir,
 	}
-	runtimeNoFile := newExtensionRuntime(extNoFile)
+	runtimeNoFile := NewExtensionRuntime(extNoFile)
 	_, err = runtimeNoFile.validatePath("test.txt")
 	if err == nil {
 		t.Error("Expected file access to be denied without file permission")
@@ -221,7 +195,7 @@ func TestExtensionRuntime_FileSandbox(t *testing.T) {
 }
 
 func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
-	ext := &loadedExtension{
+	ext := &LoadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -229,7 +203,7 @@ func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 	vm := goja.New()
 	runtime.RegisterAPIs(vm)
 
@@ -261,177 +235,15 @@ func TestExtensionRuntime_UtilityFunctions(t *testing.T) {
 	if err != nil {
 		t.Fatalf("stringifyJSON failed: %v", err)
 	}
+	// JSON output may vary in order, just check it's valid
 	if result.String() == "" {
 		t.Error("Expected non-empty JSON string")
 	}
-
-	result, err = vm.RunString(`utils.sleep(1)`)
-	if err != nil {
-		t.Fatalf("sleep failed: %v", err)
-	}
-	if !result.ToBoolean() {
-		t.Error("Expected sleep to complete successfully")
-	}
-
-	runtime.setActiveDownloadItemID("test-item")
-	cancelDownload("test-item")
-	t.Cleanup(func() {
-		clearDownloadCancel("test-item")
-		runtime.clearActiveDownloadItemID()
-	})
-
-	result, err = vm.RunString(`utils.isDownloadCancelled()`)
-	if err != nil {
-		t.Fatalf("isDownloadCancelled failed: %v", err)
-	}
-	if !result.ToBoolean() {
-		t.Error("Expected active download cancellation to be visible to JS")
-	}
-
-	SetAppVersion("4.2.2")
-	t.Cleanup(func() {
-		SetAppVersion("")
-	})
-
-	result, err = vm.RunString(`utils.appVersion()`)
-	if err != nil {
-		t.Fatalf("appVersion failed: %v", err)
-	}
-	if got := result.String(); got != "4.2.2" {
-		t.Fatalf("Expected appVersion 4.2.2, got %q", got)
-	}
-
-	result, err = vm.RunString(`utils.appUserAgent()`)
-	if err != nil {
-		t.Fatalf("appUserAgent failed: %v", err)
-	}
-	if got := result.String(); got != "SpotiFLAC-Mobile/4.2.2" {
-		t.Fatalf("Expected appUserAgent SpotiFLAC-Mobile/4.2.2, got %q", got)
-	}
-
-	result, err = vm.RunString(`utils.sleep(50)`)
-	if err != nil {
-		t.Fatalf("cancel-aware sleep failed: %v", err)
-	}
-	if result.ToBoolean() {
-		t.Error("Expected sleep to abort when download is cancelled")
-	}
-}
-
-func TestExtensionRuntime_BindDownloadCancelContext(t *testing.T) {
-	ext := &loadedExtension{
-		ID: "test-ext",
-		Manifest: &ExtensionManifest{
-			Name: "test-ext",
-		},
-		DataDir: t.TempDir(),
-	}
-
-	runtime := newExtensionRuntime(ext)
-	runtime.setActiveDownloadItemID("test-item")
-	t.Cleanup(func() {
-		clearDownloadCancel("test-item")
-		runtime.clearActiveDownloadItemID()
-	})
-
-	req, err := http.NewRequest("GET", "https://api.example.com/test", nil)
-	if err != nil {
-		t.Fatalf("NewRequest failed: %v", err)
-	}
-
-	req = runtime.bindDownloadCancelContext(req)
-	cancelDownload("test-item")
-
-	select {
-	case <-req.Context().Done():
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("Expected bound request context to be cancelled")
-	}
-
-	if req.Context().Err() == nil {
-		t.Fatal("Expected request context error after cancellation")
-	}
-}
-
-func TestExtensionRuntime_BindDownloadCancelContextPreservesPreCancelledState(t *testing.T) {
-	ext := &loadedExtension{
-		ID: "test-ext",
-		Manifest: &ExtensionManifest{
-			Name: "test-ext",
-		},
-		DataDir: t.TempDir(),
-	}
-
-	runtime := newExtensionRuntime(ext)
-	runtime.setActiveDownloadItemID("test-item")
-	cancelDownload("test-item")
-	t.Cleanup(func() {
-		clearDownloadCancel("test-item")
-		runtime.clearActiveDownloadItemID()
-	})
-
-	req, err := http.NewRequest("GET", "https://api.example.com/test", nil)
-	if err != nil {
-		t.Fatalf("NewRequest failed: %v", err)
-	}
-
-	req = runtime.bindDownloadCancelContext(req)
-
-	select {
-	case <-req.Context().Done():
-	case <-time.After(500 * time.Millisecond):
-		t.Fatal("Expected pre-cancelled request context to stay cancelled")
-	}
-
-	if req.Context().Err() == nil {
-		t.Fatal("Expected request context error for pre-cancelled item")
-	}
-}
-
-func TestRunWithTimeoutContextCancelsExecution(t *testing.T) {
-	vm := goja.New()
-	ctx, cancel := context.WithCancel(context.Background())
-	cancel()
-
-	_, err := RunWithTimeoutContextAndRecover(ctx, vm, `while (true) {}`, 5*time.Second)
-	if !errors.Is(err, ErrExtensionRequestCancelled) {
-		t.Fatalf("expected extension request cancellation, got %v", err)
-	}
-}
-
-func TestExtensionRuntime_BindExtensionRequestCancelContext(t *testing.T) {
-	ext := &loadedExtension{
-		ID: "test-ext",
-		Manifest: &ExtensionManifest{
-			Name: "test-ext",
-		},
-		DataDir: t.TempDir(),
-	}
-	runtime := newExtensionRuntime(ext)
-
-	const requestID = "test-extension-request"
-	clearExtensionRequestCancel(requestID)
-	defer clearExtensionRequestCancel(requestID)
-
-	runtime.setActiveRequestID(requestID)
-	defer runtime.clearActiveRequestID()
-
-	req, err := http.NewRequest(http.MethodGet, "https://example.com", nil)
-	if err != nil {
-		t.Fatalf("new request: %v", err)
-	}
-	req = runtime.bindDownloadCancelContext(req)
-
-	cancelExtensionRequest(requestID)
-	select {
-	case <-req.Context().Done():
-	case <-time.After(time.Second):
-		t.Fatal("expected request context to be cancelled")
-	}
 }
 
 func TestExtensionRuntime_SSRFProtection(t *testing.T) {
-	ext := &loadedExtension{
+	// Create extension with limited network permissions
+	ext := &LoadedExtension{
 		ID: "test-ext",
 		Manifest: &ExtensionManifest{
 			Name: "test-ext",
@@ -442,7 +254,7 @@ func TestExtensionRuntime_SSRFProtection(t *testing.T) {
 		DataDir: t.TempDir(),
 	}
 
-	runtime := newExtensionRuntime(ext)
+	runtime := NewExtensionRuntime(ext)
 
 	privateIPs := []string{
 		"http://localhost/admin",

go_backend/extension_timeout.go

@@ -20,22 +20,11 @@ func (e *JSExecutionError) Error() string {
 }
 
 func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
-	return RunWithTimeoutContext(context.Background(), vm, script, timeout)
-}
-
-func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
-	if vm == nil {
-		return nil, fmt.Errorf("extension runtime unavailable")
-	}
-
 	if timeout <= 0 {
 		timeout = DefaultJSTimeout
 	}
 
-	if ctx == nil {
-		ctx = context.Background()
-	}
-	ctx, cancel := context.WithTimeout(ctx, timeout)
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
 	type result struct {
@@ -60,7 +49,7 @@ func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string,
 						IsTimeout: true,
 					}}
 				} else {
-					GoLog("[extensionRuntime] panic during JS execution: %v\n%s\n", r, string(debug.Stack()))
+					GoLog("[ExtensionRuntime] panic during JS execution: %v\n%s\n", r, string(debug.Stack()))
 					resultCh <- result{nil, fmt.Errorf("panic during execution: %v", r)}
 				}
 			}
@@ -74,27 +63,14 @@ func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string,
 	case res := <-resultCh:
 		return res.value, res.err
 	case <-ctx.Done():
-		cancelled := ctx.Err() == context.Canceled
 		interruptMu.Lock()
 		interrupted = true
 		interruptMu.Unlock()
 
-		if cancelled {
-			vm.Interrupt("extension request cancelled")
-		} else {
-			vm.Interrupt("execution timeout")
-		}
+		vm.Interrupt("execution timeout")
 
-		// MUST wait for the goroutine to finish before returning.
-		// The Goja VM is NOT thread-safe — if we return while the goroutine
-		// is still executing JS (e.g. blocked on an HTTP call), the next
-		// caller will access the VM concurrently and crash with a nil
-		// pointer dereference.
 		select {
 		case res := <-resultCh:
-			if cancelled {
-				return nil, ErrExtensionRequestCancelled
-			}
 			if res.err != nil {
 				return nil, res.err
 			}
@@ -102,13 +78,7 @@ func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string,
 				Message:   "execution timeout exceeded",
 				IsTimeout: true,
 			}
-		case <-time.After(60 * time.Second):
-			// Goroutine is truly stuck (e.g. HTTP read with no timeout).
-			// Log a warning — the VM should NOT be reused after this.
-			GoLog("[extensionRuntime] WARNING: JS goroutine did not exit within 60s after interrupt, VM may be unsafe\n")
-			if cancelled {
-				return nil, ErrExtensionRequestCancelled
-			}
+		case <-time.After(1 * time.Second):
 			return nil, &JSExecutionError{
 				Message:   "execution timeout exceeded (force)",
 				IsTimeout: true,
@@ -120,15 +90,10 @@ func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string,
 // RunWithTimeoutAndRecover runs JS with timeout and clears interrupt state after
 // This should be used when you want to continue using the VM after a timeout
 func RunWithTimeoutAndRecover(vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
-	return RunWithTimeoutContextAndRecover(context.Background(), vm, script, timeout)
-}
+	result, err := RunWithTimeout(vm, script, timeout)
 
-func RunWithTimeoutContextAndRecover(ctx context.Context, vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
-	result, err := RunWithTimeoutContext(ctx, vm, script, timeout)
-
-	if vm != nil {
-		vm.ClearInterrupt()
-	}
+	// Clear any interrupt state so VM can be reused
+	vm.ClearInterrupt()
 
 	return result, err
 }

go_backend/filename.go

@@ -6,8 +6,6 @@ import (
 	"strconv"
 	"strings"
 	"time"
-	"unicode"
-	"unicode/utf8"
 )
 
 var (
@@ -19,66 +17,24 @@ var (
 )
 
 func sanitizeFilename(filename string) string {
-	sanitized := strings.ReplaceAll(filename, "/", " ")
-	sanitized = invalidChars.ReplaceAllString(sanitized, " ")
+	sanitized := invalidChars.ReplaceAllString(filename, "_")
 
-	var builder strings.Builder
-	for _, r := range sanitized {
-		if r < 0x20 && r != 0x09 && r != 0x0A && r != 0x0D {
-			continue
-		}
-		if r == 0x7F {
-			continue
-		}
-		if unicode.IsControl(r) && r != 0x09 && r != 0x0A && r != 0x0D {
-			continue
-		}
-		builder.WriteRune(r)
-	}
-
-	sanitized = builder.String()
 	sanitized = strings.TrimSpace(sanitized)
-	sanitized = strings.Trim(sanitized, ". ")
-	sanitized = strings.Join(strings.Fields(sanitized), " ")
-	sanitized = multiUnderscore.ReplaceAllString(sanitized, "_")
-	sanitized = strings.Trim(sanitized, "_ ")
+	sanitized = strings.Trim(sanitized, ".")
 
-	if !utf8.ValidString(sanitized) {
-		sanitized = strings.ToValidUTF8(sanitized, "_")
-	}
+	sanitized = multiUnderscore.ReplaceAllString(sanitized, "_")
 
 	if len(sanitized) > 200 {
-		sanitized = truncateUTF8Bytes(sanitized, 200)
-		sanitized = strings.TrimSpace(strings.Trim(sanitized, ". "))
-		sanitized = strings.Trim(sanitized, "_ ")
+		sanitized = sanitized[:200]
 	}
 
 	if sanitized == "" {
-		return "Unknown"
+		sanitized = "untitled"
 	}
 
 	return sanitized
 }
 
-func truncateUTF8Bytes(value string, maxBytes int) string {
-	if maxBytes <= 0 || len(value) <= maxBytes {
-		return value
-	}
-
-	used := 0
-	for i, r := range value {
-		runeLen := utf8.RuneLen(r)
-		if runeLen < 0 {
-			runeLen = len(string(r))
-		}
-		if used+runeLen > maxBytes {
-			return value[:i]
-		}
-		used += runeLen
-	}
-	return value
-}
-
 func buildFilenameFromTemplate(template string, metadata map[string]interface{}) string {
 	if template == "" {
 		template = "{artist} - {title}"

go_backend/filename_test.go

@@ -1,10 +1,6 @@
 package gobackend
 
-import (
-	"strings"
-	"testing"
-	"unicode/utf8"
-)
+import "testing"
 
 func TestBuildFilenameFromTemplate_WithRawTrackAndDisc(t *testing.T) {
 	metadata := map[string]interface{}{
@@ -87,28 +83,3 @@ func TestBuildFilenameFromTemplate_DateStrftimeFormattingWithYearOnly(t *testing
 		t.Fatalf("expected %q, got %q", expected, formatted)
 	}
 }
-
-func TestSanitizeFilenameMatchesDesktopSpacingBehavior(t *testing.T) {
-	got := sanitizeFilename(`  "Text In Quotes"?%* / Demo  `)
-	want := "Text In Quotes % Demo"
-	if got != want {
-		t.Fatalf("expected %q, got %q", want, got)
-	}
-}
-
-func TestSanitizeFilenameFallsBackToUnknownWhenEmpty(t *testing.T) {
-	got := sanitizeFilename(`<>:"/\|?*`)
-	if got != "Unknown" {
-		t.Fatalf("expected %q, got %q", "Unknown", got)
-	}
-}
-
-func TestSanitizeFilenameTruncatesWithoutSplittingUTF8(t *testing.T) {
-	got := sanitizeFilename(strings.Repeat("あ", 80))
-	if !utf8.ValidString(got) {
-		t.Fatalf("sanitizeFilename returned invalid UTF-8: %q", got)
-	}
-	if len(got) > 200 {
-		t.Fatalf("sanitizeFilename length = %d, want <= 200", len(got))
-	}
-}

go_backend/go.mod

@@ -2,28 +2,28 @@ module github.com/zarz/spotiflac_android/go_backend
 
 go 1.25.0
 
-toolchain go1.25.9
+toolchain go1.25.7
 
 require (
-	github.com/dop251/goja v0.0.0-20260311135729-065cd970411c
+	github.com/dop251/goja v0.0.0-20260216154549-8b74ce4618c5
 	github.com/go-flac/flacpicture/v2 v2.0.2
 	github.com/go-flac/flacvorbis/v2 v2.0.2
 	github.com/go-flac/go-flac/v2 v2.0.4
 	github.com/refraction-networking/utls v1.8.2
-	golang.org/x/crypto v0.50.0
-	golang.org/x/mobile v0.0.0-20260410095206-2cfb76559b7b
-	golang.org/x/net v0.53.0
-	golang.org/x/text v0.36.0
+	golang.org/x/mobile v0.0.0-20260211191516-dcd2a3258864
+	golang.org/x/net v0.50.0
+	golang.org/x/text v0.34.0
 )
 
 require (
-	github.com/andybalholm/brotli v1.2.0 // indirect
-	github.com/dlclark/regexp2 v1.11.5 // indirect
-	github.com/go-sourcemap/sourcemap v2.1.4+incompatible // indirect
-	github.com/google/pprof v0.0.0-20260302011040-a15ffb7f9dcc // indirect
-	github.com/klauspost/compress v1.18.5 // indirect
-	golang.org/x/mod v0.35.0 // indirect
-	golang.org/x/sync v0.20.0 // indirect
-	golang.org/x/sys v0.43.0 // indirect
-	golang.org/x/tools v0.44.0 // indirect
+	github.com/andybalholm/brotli v1.0.6 // indirect
+	github.com/dlclark/regexp2 v1.11.4 // indirect
+	github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect
+	github.com/google/pprof v0.0.0-20230207041349-798e818bf904 // indirect
+	github.com/klauspost/compress v1.17.4 // indirect
+	golang.org/x/crypto v0.48.0 // indirect
+	golang.org/x/mod v0.33.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/tools v0.42.0 // indirect
 )

go_backend/go.sum

@@ -1,51 +1,49 @@
 github.com/Masterminds/semver/v3 v3.2.1 h1:RN9w6+7QoMeJVGyfmbcgs28Br8cvmnucEXnY0rYXWg0=
 github.com/Masterminds/semver/v3 v3.2.1/go.mod h1:qvl/7zhW3nngYb5+80sSMF+FG2BjYrf8m9wsX0PNOMQ=
-github.com/andybalholm/brotli v1.2.0 h1:ukwgCxwYrmACq68yiUqwIWnGY0cTPox/M94sVwToPjQ=
-github.com/andybalholm/brotli v1.2.0/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
+github.com/andybalholm/brotli v1.0.6 h1:Yf9fFpf49Zrxb9NlQaluyE92/+X7UVHlhMNJN2sxfOI=
+github.com/andybalholm/brotli v1.0.6/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dlclark/regexp2 v1.11.5 h1:Q/sSnsKerHeCkc/jSTNq1oCm7KiVgUMZRDUoRu0JQZQ=
-github.com/dlclark/regexp2 v1.11.5/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
-github.com/dop251/goja v0.0.0-20260311135729-065cd970411c h1:OcLmPfx1T1RmZVHHFwWMPaZDdRf0DBMZOFMVWJa7Pdk=
-github.com/dop251/goja v0.0.0-20260311135729-065cd970411c/go.mod h1:MxLav0peU43GgvwVgNbLAj1s/bSGboKkhuULvq/7hx4=
+github.com/dlclark/regexp2 v1.11.4 h1:rPYF9/LECdNymJufQKmri9gV604RvvABwgOA8un7yAo=
+github.com/dlclark/regexp2 v1.11.4/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dop251/goja v0.0.0-20260216154549-8b74ce4618c5 h1:QckvTXtu55YMopmVeDrPQ/r+T6xjw8KMCmE3UgUldkw=
+github.com/dop251/goja v0.0.0-20260216154549-8b74ce4618c5/go.mod h1:MxLav0peU43GgvwVgNbLAj1s/bSGboKkhuULvq/7hx4=
 github.com/go-flac/flacpicture/v2 v2.0.2 h1:HCaJIVZpxnpdWs6G3ECEVRelzqS5xOi1Ba1AGmtXbzE=
 github.com/go-flac/flacpicture/v2 v2.0.2/go.mod h1:DMZBPWPAmdLqNhqFSy5ZBs9wyBzOekXutGfP7/TFCuo=
 github.com/go-flac/flacvorbis/v2 v2.0.2 h1:xCL3OhxrxWkHrbWUBvGNe+6FQ03yLmBbz0v5z4V2PoQ=
 github.com/go-flac/flacvorbis/v2 v2.0.2/go.mod h1:SwTB5gs13VaM/N7rstwPoUsPibiMKklgwybYP9dYo2g=
 github.com/go-flac/go-flac/v2 v2.0.4 h1:atf/kFa8U9idtkA//NO22XGr+MzQLeXZecnmP9sYBf0=
 github.com/go-flac/go-flac/v2 v2.0.4/go.mod h1:sYOlTKxutMW0RDYF+KlD6Zn+VOCZlIFQG/r/usPveCs=
-github.com/go-sourcemap/sourcemap v2.1.4+incompatible h1:a+iTbH5auLKxaNwQFg0B+TCYl6lbukKPc7b5x0n1s6Q=
-github.com/go-sourcemap/sourcemap v2.1.4+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyLFfuisuzeidWPMPWmECqU=
+github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/pprof v0.0.0-20260302011040-a15ffb7f9dcc h1:VBbFa1lDYWEeV5FZKUiYKYT0VxCp9twUmmaq9eb8sXw=
-github.com/google/pprof v0.0.0-20260302011040-a15ffb7f9dcc/go.mod h1:MxpfABSjhmINe3F1It9d+8exIHFvUqtLIRCdOGNXqiI=
-github.com/klauspost/compress v1.18.5 h1:/h1gH5Ce+VWNLSWqPzOVn6XBO+vJbCNGvjoaGBFW2IE=
-github.com/klauspost/compress v1.18.5/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
+github.com/google/pprof v0.0.0-20230207041349-798e818bf904 h1:4/hN5RUoecvl+RmJRE2YxKWtnnQls6rQjjW5oV7qg2U=
+github.com/google/pprof v0.0.0-20230207041349-798e818bf904/go.mod h1:uglQLonpP8qtYCYyzA+8c/9qtqgA3qsXGYqCPKARAFg=
+github.com/klauspost/compress v1.17.4 h1:Ej5ixsIri7BrIjBkRZLTo6ghwrEtHFk7ijlczPW4fZ4=
+github.com/klauspost/compress v1.17.4/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/refraction-networking/utls v1.8.2 h1:j4Q1gJj0xngdeH+Ox/qND11aEfhpgoEvV+S9iJ2IdQo=
 github.com/refraction-networking/utls v1.8.2/go.mod h1:jkSOEkLqn+S/jtpEHPOsVv/4V4EVnelwbMQl4vCWXAM=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
-github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
-golang.org/x/crypto v0.50.0 h1:zO47/JPrL6vsNkINmLoo/PH1gcxpls50DNogFvB5ZGI=
-golang.org/x/crypto v0.50.0/go.mod h1:3muZ7vA7PBCE6xgPX7nkzzjiUq87kRItoJQM1Yo8S+Q=
-golang.org/x/mobile v0.0.0-20260410095206-2cfb76559b7b h1:Qt2eaXcZ8x20iAcoZ6AceeMMtnjuPHvC51KRCH1DKSQ=
-golang.org/x/mobile v0.0.0-20260410095206-2cfb76559b7b/go.mod h1:5Fu78lew5ucMXt8w2KYcwvxu2rkC/liHzUvaoiI+H/M=
-golang.org/x/mod v0.35.0 h1:Ww1D637e6Pg+Zb2KrWfHQUnH2dQRLBQyAtpr/haaJeM=
-golang.org/x/mod v0.35.0/go.mod h1:+GwiRhIInF8wPm+4AoT6L0FA1QWAad3OMdTRx4tFYlU=
-golang.org/x/net v0.53.0 h1:d+qAbo5L0orcWAr0a9JweQpjXF19LMXJE8Ey7hwOdUA=
-golang.org/x/net v0.53.0/go.mod h1:JvMuJH7rrdiCfbeHoo3fCQU24Lf5JJwT9W3sJFulfgs=
-golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
-golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
-golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
-golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
-golang.org/x/tools v0.44.0 h1:UP4ajHPIcuMjT1GqzDWRlalUEoY+uzoZKnhOjbIPD2c=
-golang.org/x/tools v0.44.0/go.mod h1:KA0AfVErSdxRZIsOVipbv3rQhVXTnlU6UhKxHd1seDI=
+golang.org/x/crypto v0.48.0 h1:/VRzVqiRSggnhY7gNRxPauEQ5Drw9haKdM0jqfcCFts=
+golang.org/x/crypto v0.48.0/go.mod h1:r0kV5h3qnFPlQnBSrULhlsRfryS2pmewsg+XfMgkVos=
+golang.org/x/mobile v0.0.0-20260211191516-dcd2a3258864 h1:cTVynMSsMYgbUrtia2HB1jrhdUwQNtQti91vUCyjMp4=
+golang.org/x/mobile v0.0.0-20260211191516-dcd2a3258864/go.mod h1:4OGHIUSBiIqyFAQDaX1tpY0BVnO20DvNDeATBu8aeFQ=
+golang.org/x/mod v0.33.0 h1:tHFzIWbBifEmbwtGz65eaWyGiGZatSrT9prnU8DbVL8=
+golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
+golang.org/x/net v0.50.0 h1:ucWh9eiCGyDR3vtzso0WMQinm2Dnt8cFMuQa9K33J60=
+golang.org/x/net v0.50.0/go.mod h1:UgoSli3F/pBgdJBHCTc+tp3gmrU4XswgGRgtnwWTfyM=
+golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
+golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
+golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
+golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

go_backend/httputil.go

@@ -16,19 +16,6 @@ import (
 	"time"
 )
 
-func userAgentForURL(u *url.URL) string {
-	if u == nil {
-		return getRandomUserAgent()
-	}
-
-	host := strings.ToLower(strings.TrimSpace(u.Hostname()))
-	if host == "api.zarz.moe" {
-		return appUserAgent()
-	}
-
-	return getRandomUserAgent()
-}
-
 func getRandomUserAgent() string {
 	chromeVersion := rand.Intn(26) + 120
 	chromeBuild := rand.Intn(1500) + 6000
@@ -79,6 +66,9 @@ var sharedTransport = &http.Transport{
 	DisableCompression:    true,
 }
 
+// metadataTransport is a separate transport for metadata API calls (Deezer, Spotify, SongLink).
+// Isolated from download traffic so that download failures cannot poison
+// the connection pool used by metadata enrichment.
 var metadataTransport = &http.Transport{
 	DialContext: (&net.Dialer{
 		Timeout:   30 * time.Second,
@@ -114,6 +104,8 @@ func NewHTTPClientWithTimeout(timeout time.Duration) *http.Client {
 	}
 }
 
+// NewMetadataHTTPClient creates an HTTP client using the isolated metadata transport.
+// Use this for API calls that should not be affected by download traffic.
 func NewMetadataHTTPClient(timeout time.Duration) *http.Client {
 	return &http.Client{
 		Transport: newCompatibilityTransport(metadataTransport),
@@ -237,8 +229,9 @@ func cloneRequestWithHTTPScheme(req *http.Request, scheme string) (*http.Request
 	return reqCopy, nil
 }
 
+// Also checks for ISP blocking on errors
 func DoRequestWithUserAgent(client *http.Client, req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", userAgentForURL(req.URL))
+	req.Header.Set("User-Agent", getRandomUserAgent())
 	resp, err := client.Do(req)
 	if err != nil {
 		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
@@ -246,6 +239,7 @@ func DoRequestWithUserAgent(client *http.Client, req *http.Request) (*http.Respo
 	return resp, err
 }
 
+// RetryConfig holds configuration for retry logic
 type RetryConfig struct {
 	MaxRetries    int
 	InitialDelay  time.Duration
@@ -268,7 +262,7 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 
 	for attempt := 0; attempt <= config.MaxRetries; attempt++ {
 		reqCopy := req.Clone(req.Context())
-		reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
+		reqCopy.Header.Set("User-Agent", getRandomUserAgent())
 
 		resp, err := client.Do(reqCopy)
 		if err != nil {

go_backend/httputil_ios.go

@@ -6,12 +6,19 @@ import (
 	"net/http"
 )
 
+// iOS version: uTLS is not supported on iOS due to cgo DNS resolver issues
+// Fall back to standard HTTP client
+
+// GetCloudflareBypassClient returns the standard HTTP client on iOS
+// uTLS is not available on iOS due to cgo DNS resolver compatibility issues
 func GetCloudflareBypassClient() *http.Client {
 	return sharedClient
 }
 
+// DoRequestWithCloudflareBypass on iOS just uses the standard client
+// uTLS Chrome fingerprint bypass is not available on iOS
 func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", userAgentForURL(req.URL))
+	req.Header.Set("User-Agent", getRandomUserAgent())
 	resp, err := sharedClient.Do(req)
 	if err != nil {
 		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")

go_backend/httputil_supplement_test.go

@@ -1,158 +0,0 @@
-package gobackend
-
-import (
-	"errors"
-	"io"
-	"net/http"
-	"net/url"
-	"strings"
-	"testing"
-	"time"
-)
-
-func TestHTTPUtilityHelpers(t *testing.T) {
-	SetAppVersion("7.0.0")
-	apiURL := mustParseURL(t, "https://api.zarz.moe/test")
-	if ua := userAgentForURL(apiURL); !strings.Contains(ua, "7.0.0") {
-		t.Fatalf("api user agent = %q", ua)
-	}
-	if userAgentForURL(nil) == "" || userAgentForURL(mustParseURL(t, "https://example.com")) == "" {
-		t.Fatal("expected fallback user agent")
-	}
-	if NewHTTPClientWithTimeout(time.Second).Timeout != time.Second || NewMetadataHTTPClient(time.Second).Timeout != time.Second {
-		t.Fatal("client timeout mismatch")
-	}
-	if GetSharedClient() == nil || GetDownloadClient() == nil {
-		t.Fatal("expected shared clients")
-	}
-	SetNetworkCompatibilityOptions(true, true)
-	if opts := GetNetworkCompatibilityOptions(); !opts.AllowHTTP || !opts.InsecureTLS {
-		t.Fatalf("network opts = %#v", opts)
-	}
-	SetNetworkCompatibilityOptions(false, false)
-	if !canFallbackToHTTP(&http.Request{Method: http.MethodGet}) {
-		t.Fatal("GET should fallback")
-	}
-	if canFallbackToHTTP(&http.Request{Method: http.MethodPost}) {
-		t.Fatal("POST without GetBody should not fallback")
-	}
-	req, _ := http.NewRequest(http.MethodPost, "https://example.com/path", strings.NewReader("body"))
-	req.GetBody = func() (io.ReadCloser, error) { return io.NopCloser(strings.NewReader("body")), nil }
-	cloned, err := cloneRequestWithHTTPScheme(req, "http")
-	if err != nil || cloned.URL.Scheme != "http" || cloned.Body == nil {
-		t.Fatalf("cloneRequestWithHTTPScheme = %#v/%v", cloned, err)
-	}
-
-	client := &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		if req.Header.Get("User-Agent") == "" {
-			t.Fatal("missing User-Agent")
-		}
-		return &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader("ok")), Request: req}, nil
-	})}
-	resp, err := DoRequestWithUserAgent(client, mustNewRequest(t, "https://example.com/ok"))
-	if err != nil || resp.StatusCode != 200 {
-		t.Fatalf("DoRequestWithUserAgent = %#v/%v", resp, err)
-	}
-	resp.Body.Close()
-
-	attempts := 0
-	retryClient := &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		attempts++
-		switch attempts {
-		case 1:
-			return &http.Response{StatusCode: 500, Body: io.NopCloser(strings.NewReader("server")), Request: req}, nil
-		case 2:
-			return &http.Response{StatusCode: 429, Header: http.Header{"Retry-After": []string{"0"}}, Body: io.NopCloser(strings.NewReader("rate")), Request: req}, nil
-		default:
-			return &http.Response{StatusCode: 204, Body: io.NopCloser(strings.NewReader("")), Request: req}, nil
-		}
-	})}
-	resp, err = DoRequestWithRetry(retryClient, mustNewRequest(t, "https://example.com/retry"), RetryConfig{MaxRetries: 3, InitialDelay: 0, MaxDelay: time.Millisecond, BackoffFactor: 2})
-	if err != nil || resp.StatusCode != 204 || attempts != 3 {
-		t.Fatalf("DoRequestWithRetry = %#v/%v attempts=%d", resp, err, attempts)
-	}
-	resp.Body.Close()
-	blockingClient := &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
-		return &http.Response{StatusCode: 403, Body: io.NopCloser(strings.NewReader("access denied by region")), Request: req}, nil
-	})}
-	if _, err := DoRequestWithRetry(blockingClient, mustNewRequest(t, "https://blocked.example.com"), RetryConfig{MaxRetries: 0}); err == nil {
-		t.Fatal("expected blocking retry error")
-	}
-
-	if _, err := ReadResponseBody(nil); err == nil {
-		t.Fatal("expected nil response body error")
-	}
-	if _, err := ReadResponseBody(&http.Response{Body: io.NopCloser(strings.NewReader(""))}); err == nil {
-		t.Fatal("expected empty response body error")
-	}
-	if body, err := ReadResponseBody(&http.Response{Body: io.NopCloser(strings.NewReader("ok"))}); err != nil || string(body) != "ok" {
-		t.Fatalf("ReadResponseBody = %q/%v", body, err)
-	}
-	if err := ValidateResponse(nil); err == nil {
-		t.Fatal("expected nil response validation error")
-	}
-	if err := ValidateResponse(&http.Response{StatusCode: 404, Status: "404 Not Found"}); err == nil {
-		t.Fatal("expected bad status validation error")
-	}
-	if err := ValidateResponse(&http.Response{StatusCode: 200}); err != nil {
-		t.Fatalf("ValidateResponse: %v", err)
-	}
-	if msg := BuildErrorMessage("api", 500, strings.Repeat("x", 120)); !strings.Contains(msg, "...") {
-		t.Fatalf("BuildErrorMessage = %q", msg)
-	}
-	if calculateNextDelay(10*time.Millisecond, RetryConfig{BackoffFactor: 3, MaxDelay: 20 * time.Millisecond}) != 20*time.Millisecond {
-		t.Fatal("calculateNextDelay mismatch")
-	}
-	if getRetryAfterDuration(&http.Response{Header: http.Header{"Retry-After": []string{"bad"}}}) != 0 {
-		t.Fatal("invalid retry-after should be zero")
-	}
-	if isp := IsISPBlocking(errors.New("connection reset by peer"), "https://example.com/x"); isp == nil || !strings.Contains(isp.Error(), "example.com") {
-		t.Fatalf("IsISPBlocking = %#v", isp)
-	}
-	if !CheckAndLogISPBlocking(errors.New("i/o timeout"), "https://timeout.example/x", "test") {
-		t.Fatal("expected logged ISP blocking")
-	}
-	if wrapped := WrapErrorWithISPCheck(errors.New("connection refused"), "https://refused.example/x", "test"); wrapped == nil || !strings.Contains(wrapped.Error(), "ISP blocking") {
-		t.Fatalf("WrapErrorWithISPCheck = %v", wrapped)
-	}
-	if WrapErrorWithISPCheck(nil, "", "test") != nil {
-		t.Fatal("nil wrap should stay nil")
-	}
-	if extractDomain("https://example.com/path") != "example.com" || extractDomain("bad://") != "unknown" || extractDomain("") != "unknown" {
-		t.Fatal("extractDomain mismatch")
-	}
-}
-
-func TestRateLimiterHelpers(t *testing.T) {
-	limiter := NewRateLimiter(1, time.Hour)
-	if limiter.Available() != 1 {
-		t.Fatalf("available = %d", limiter.Available())
-	}
-	if !limiter.TryAcquire() || limiter.TryAcquire() {
-		t.Fatal("TryAcquire mismatch")
-	}
-	if limiter.Available() != 0 {
-		t.Fatalf("available after acquire = %d", limiter.Available())
-	}
-	if GetSongLinkRateLimiter() == nil {
-		t.Fatal("expected global limiter")
-	}
-}
-
-func mustNewRequest(t *testing.T, rawURL string) *http.Request {
-	t.Helper()
-	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return req
-}
-
-func mustParseURL(t *testing.T, rawURL string) *url.URL {
-	t.Helper()
-	parsed, err := url.Parse(rawURL)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return parsed
-}

go_backend/httputil_utls.go

@@ -10,13 +10,18 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"sync"
 
 	utls "github.com/refraction-networking/utls"
 	"golang.org/x/net/http2"
 )
 
+// uTLS transport that mimics Chrome's TLS fingerprint to bypass Cloudflare
+// Uses HTTP/2 for optimal performance as uTLS works best with HTTP/2
 type utlsTransport struct {
-	dialer *net.Dialer
+	dialer       *net.Dialer
+	mu           sync.Mutex
+	h2Transports map[string]*http2.Transport
 }
 
 func newUTLSTransport() *utlsTransport {
@@ -25,6 +30,7 @@ func newUTLSTransport() *utlsTransport {
 			Timeout:   30 * Second,
 			KeepAlive: 30 * Second,
 		},
+		h2Transports: make(map[string]*http2.Transport),
 	}
 }
 
@@ -92,12 +98,17 @@ var cloudflareBypassClient = &http.Client{
 	Timeout:   DefaultTimeout,
 }
 
+// GetCloudflareBypassClient returns an HTTP client that mimics Chrome's TLS fingerprint
+// Use this when requests are blocked by Cloudflare (common when using VPN)
 func GetCloudflareBypassClient() *http.Client {
 	return cloudflareBypassClient
 }
 
+// DoRequestWithCloudflareBypass attempts request with standard client first,
+// then retries with uTLS Chrome fingerprint if Cloudflare blocks it.
+// This is useful when using VPN as Cloudflare detects Go's default TLS fingerprint.
 func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
-	req.Header.Set("User-Agent", userAgentForURL(req.URL))
+	req.Header.Set("User-Agent", getRandomUserAgent())
 
 	resp, err := sharedClient.Do(req)
 	if err == nil {
@@ -125,12 +136,13 @@ func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
 					LogDebug("HTTP", "Cloudflare detected, retrying with Chrome TLS fingerprint...")
 
 					reqCopy := req.Clone(req.Context())
-					reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
+					reqCopy.Header.Set("User-Agent", getRandomUserAgent())
 
 					return cloudflareBypassClient.Do(reqCopy)
 				}
 			}
 
+			// Not Cloudflare, return original response (recreate body)
 			return &http.Response{
 				Status:     resp.Status,
 				StatusCode: resp.StatusCode,
@@ -151,7 +163,7 @@ func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
 		LogDebug("HTTP", "TLS error detected, retrying with Chrome TLS fingerprint: %v", err)
 
 		reqCopy := req.Clone(req.Context())
-		reqCopy.Header.Set("User-Agent", userAgentForURL(reqCopy.URL))
+		reqCopy.Header.Set("User-Agent", getRandomUserAgent())
 
 		return cloudflareBypassClient.Do(reqCopy)
 	}

go_backend/idhs.go

@@ -10,6 +10,8 @@ import (
 	"time"
 )
 
+// IDHSClient is a client for I Don't Have Spotify API
+// Used as fallback when SongLink fails or is rate limited
 type IDHSClient struct {
 	client *http.Client
 }
@@ -53,6 +55,7 @@ func NewIDHSClient() *IDHSClient {
 	return globalIDHSClient
 }
 
+// Search converts a music link to links on other platforms
 func (c *IDHSClient) Search(link string, adapters []string) (*IDHSSearchResponse, error) {
 	idhsRateLimiter.WaitForSlot()
 
@@ -106,6 +109,7 @@ func (c *IDHSClient) Search(link string, adapters []string) (*IDHSSearchResponse
 	return &result, nil
 }
 
+// GetAvailabilityFromSpotify checks track availability using IDHS as fallback
 func (c *IDHSClient) GetAvailabilityFromSpotify(spotifyTrackID string) (*TrackAvailability, error) {
 	spotifyURL := fmt.Sprintf("https://open.spotify.com/track/%s", spotifyTrackID)
 

go_backend/library_scan.go

@@ -24,18 +24,13 @@ type LibraryScanResult struct {
 	FileModTime          int64  `json:"fileModTime,omitempty"` // Unix timestamp in milliseconds
 	ISRC                 string `json:"isrc,omitempty"`
 	TrackNumber          int    `json:"trackNumber,omitempty"`
-	TotalTracks          int    `json:"totalTracks,omitempty"`
 	DiscNumber           int    `json:"discNumber,omitempty"`
-	TotalDiscs           int    `json:"totalDiscs,omitempty"`
 	Duration             int    `json:"duration,omitempty"`
 	ReleaseDate          string `json:"releaseDate,omitempty"`
 	BitDepth             int    `json:"bitDepth,omitempty"`
 	SampleRate           int    `json:"sampleRate,omitempty"`
 	Bitrate              int    `json:"bitrate,omitempty"` // kbps, for lossy formats (MP3, Opus, Vorbis)
 	Genre                string `json:"genre,omitempty"`
-	Composer             string `json:"composer,omitempty"`
-	Label                string `json:"label,omitempty"`
-	Copyright            string `json:"copyright,omitempty"`
 	Format               string `json:"format,omitempty"`
 	MetadataFromFilename bool   `json:"metadataFromFilename,omitempty"`
 }
@@ -71,9 +66,6 @@ var supportedAudioFormats = map[string]bool{
 	".mp3":  true,
 	".opus": true,
 	".ogg":  true,
-	".ape":  true,
-	".wv":   true,
-	".mpc":  true,
 	".cue":  true,
 }
 
@@ -90,7 +82,7 @@ type scannedCueFileInfo struct {
 func collectLibraryAudioFiles(folderPath string, cancelCh <-chan struct{}) ([]libraryAudioFileInfo, error) {
 	var files []libraryAudioFileInfo
 
-	err := filepath.WalkDir(folderPath, func(path string, entry os.DirEntry, err error) error {
+	err := filepath.Walk(folderPath, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return nil
 		}
@@ -101,7 +93,7 @@ func collectLibraryAudioFiles(folderPath string, cancelCh <-chan struct{}) ([]li
 		default:
 		}
 
-		if entry.IsDir() {
+		if info.IsDir() {
 			return nil
 		}
 
@@ -110,11 +102,6 @@ func collectLibraryAudioFiles(folderPath string, cancelCh <-chan struct{}) ([]li
 			return nil
 		}
 
-		info, err := entry.Info()
-		if err != nil {
-			return nil
-		}
-
 		files = append(files, libraryAudioFileInfo{
 			path:    path,
 			modTime: info.ModTime().UnixMilli(),
@@ -183,9 +170,11 @@ func ScanLibraryFolder(folderPath string) (string, error) {
 	scanTime := time.Now().UTC().Format(time.RFC3339)
 	errorCount := 0
 
+	// Track audio files referenced by .cue sheets to avoid duplicates
 	cueReferencedAudioFiles := make(map[string]bool)
 	parsedCueFiles := make(map[string]scannedCueFileInfo)
 
+	// First pass: scan .cue files to collect referenced audio paths
 	for _, fileInfo := range audioFileInfos {
 		filePath := fileInfo.path
 		ext := strings.ToLower(filepath.Ext(filePath))
@@ -220,6 +209,7 @@ func ScanLibraryFolder(folderPath string) (string, error) {
 
 		ext := strings.ToLower(filepath.Ext(filePath))
 
+		// Handle .cue files: produce multiple track results
 		if ext == ".cue" {
 			var cueResults []LibraryScanResult
 			cueInfo, ok := parsedCueFiles[filePath]
@@ -276,10 +266,18 @@ func ScanLibraryFolder(folderPath string) (string, error) {
 	return string(jsonBytes), nil
 }
 
+func scanAudioFile(filePath, scanTime string) (*LibraryScanResult, error) {
+	return scanAudioFileWithKnownModTimeAndDisplayName(filePath, "", scanTime, 0)
+}
+
 func scanAudioFileWithKnownModTime(filePath, scanTime string, knownModTime int64) (*LibraryScanResult, error) {
 	return scanAudioFileWithKnownModTimeAndDisplayNameAndCoverCacheKey(filePath, "", "", scanTime, knownModTime)
 }
 
+func scanAudioFileWithKnownModTimeAndDisplayName(filePath, displayNameHint, scanTime string, knownModTime int64) (*LibraryScanResult, error) {
+	return scanAudioFileWithKnownModTimeAndDisplayNameAndCoverCacheKey(filePath, displayNameHint, "", scanTime, knownModTime)
+}
+
 func scanAudioFileWithKnownModTimeAndDisplayNameAndCoverCacheKey(filePath, displayNameHint, coverCacheKey, scanTime string, knownModTime int64) (*LibraryScanResult, error) {
 	ext := resolveLibraryAudioExt(filePath, displayNameHint)
 
@@ -320,8 +318,6 @@ func scanAudioFileWithKnownModTimeAndDisplayNameAndCoverCacheKey(filePath, displ
 		return scanMP3File(filePath, result, displayNameHint)
 	case ".opus", ".ogg":
 		return scanOggFile(filePath, result, displayNameHint)
-	case ".ape", ".wv", ".mpc":
-		return scanAPEFile(filePath, result, displayNameHint)
 	default:
 		return scanFromFilename(filePath, displayNameHint, result)
 	}
@@ -367,14 +363,9 @@ func scanFLACFile(filePath string, result *LibraryScanResult, displayNameHint st
 	result.AlbumArtist = metadata.AlbumArtist
 	result.ISRC = metadata.ISRC
 	result.TrackNumber = metadata.TrackNumber
-	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
-	result.TotalDiscs = metadata.TotalDiscs
 	result.ReleaseDate = metadata.Date
 	result.Genre = metadata.Genre
-	result.Composer = metadata.Composer
-	result.Label = metadata.Label
-	result.Copyright = metadata.Copyright
 
 	quality, err := GetAudioQuality(filePath)
 	if err == nil {
@@ -404,17 +395,12 @@ func scanM4AFile(filePath string, result *LibraryScanResult, displayNameHint str
 		result.AlbumArtist = metadata.AlbumArtist
 		result.ISRC = metadata.ISRC
 		result.TrackNumber = metadata.TrackNumber
-		result.TotalTracks = metadata.TotalTracks
 		result.DiscNumber = metadata.DiscNumber
-		result.TotalDiscs = metadata.TotalDiscs
 		result.ReleaseDate = metadata.Date
 		if result.ReleaseDate == "" {
 			result.ReleaseDate = metadata.Year
 		}
 		result.Genre = metadata.Genre
-		result.Composer = metadata.Composer
-		result.Label = metadata.Label
-		result.Copyright = metadata.Copyright
 	}
 
 	quality, err := GetM4AQuality(filePath)
@@ -439,9 +425,7 @@ func scanMP3File(filePath string, result *LibraryScanResult, displayNameHint str
 	result.AlbumName = metadata.Album
 	result.AlbumArtist = metadata.AlbumArtist
 	result.TrackNumber = metadata.TrackNumber
-	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
-	result.TotalDiscs = metadata.TotalDiscs
 	result.Genre = metadata.Genre
 	if metadata.Date != "" {
 		result.ReleaseDate = metadata.Date
@@ -449,9 +433,6 @@ func scanMP3File(filePath string, result *LibraryScanResult, displayNameHint str
 		result.ReleaseDate = metadata.Year
 	}
 	result.ISRC = metadata.ISRC
-	result.Composer = metadata.Composer
-	result.Label = metadata.Label
-	result.Copyright = metadata.Copyright
 
 	quality, err := GetMP3Quality(filePath)
 	if err == nil {
@@ -481,14 +462,9 @@ func scanOggFile(filePath string, result *LibraryScanResult, displayNameHint str
 	result.AlbumArtist = metadata.AlbumArtist
 	result.ISRC = metadata.ISRC
 	result.TrackNumber = metadata.TrackNumber
-	result.TotalTracks = metadata.TotalTracks
 	result.DiscNumber = metadata.DiscNumber
-	result.TotalDiscs = metadata.TotalDiscs
 	result.Genre = metadata.Genre
 	result.ReleaseDate = metadata.Date
-	result.Composer = metadata.Composer
-	result.Label = metadata.Label
-	result.Copyright = metadata.Copyright
 
 	quality, err := GetOggQuality(filePath)
 	if err == nil {
@@ -505,42 +481,6 @@ func scanOggFile(filePath string, result *LibraryScanResult, displayNameHint str
 	return result, nil
 }
 
-func scanAPEFile(filePath string, result *LibraryScanResult, displayNameHint string) (*LibraryScanResult, error) {
-	tag, err := ReadAPETags(filePath)
-	if err != nil {
-		GoLog("[LibraryScan] APE tag read error for %s: %v\n", filePath, err)
-		return scanFromFilename(filePath, displayNameHint, result)
-	}
-
-	metadata := APETagToAudioMetadata(tag)
-	if metadata == nil {
-		return scanFromFilename(filePath, displayNameHint, result)
-	}
-
-	result.TrackName = metadata.Title
-	result.ArtistName = metadata.Artist
-	result.AlbumName = metadata.Album
-	result.AlbumArtist = metadata.AlbumArtist
-	result.ISRC = metadata.ISRC
-	result.TrackNumber = metadata.TrackNumber
-	result.TotalTracks = metadata.TotalTracks
-	result.DiscNumber = metadata.DiscNumber
-	result.TotalDiscs = metadata.TotalDiscs
-	result.Genre = metadata.Genre
-	if metadata.Date != "" {
-		result.ReleaseDate = metadata.Date
-	} else {
-		result.ReleaseDate = metadata.Year
-	}
-	result.Composer = metadata.Composer
-	result.Label = metadata.Label
-	result.Copyright = metadata.Copyright
-
-	applyDefaultLibraryMetadata(filePath, displayNameHint, result)
-
-	return result, nil
-}
-
 func scanFromFilename(filePath, displayNameHint string, result *LibraryScanResult) (*LibraryScanResult, error) {
 	result.MetadataFromFilename = true
 	nameSource := libraryDisplayNameOrPath(filePath, displayNameHint)
@@ -887,6 +827,9 @@ func scanLibraryFolderIncrementalWithExistingFiles(folderPath string, existingFi
 	return string(jsonBytes), nil
 }
 
+// ScanLibraryFolderIncremental performs an incremental scan of the library folder
+// existingFilesJSON is a JSON object mapping filePath -> modTime (unix millis)
+// Only files that are new or have changed modification time will be scanned
 func ScanLibraryFolderIncremental(folderPath, existingFilesJSON string) (string, error) {
 	existingFiles := make(map[string]int64)
 	if existingFilesJSON != "" && existingFilesJSON != "{}" {

go_backend/library_scan_supplement_test.go

@@ -1,150 +0,0 @@
-package gobackend
-
-import (
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-)
-
-func TestLibraryScanFullIncrementalAndMetadataFallbacks(t *testing.T) {
-	dir := t.TempDir()
-	albumDir := filepath.Join(dir, "Album")
-	if err := os.MkdirAll(albumDir, 0755); err != nil {
-		t.Fatal(err)
-	}
-	mp3Path := filepath.Join(albumDir, "Artist - Song.mp3")
-	if err := os.WriteFile(mp3Path, []byte("not really mp3"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	numberedPath := filepath.Join(albumDir, "01 - Intro.ogg")
-	if err := os.WriteFile(numberedPath, []byte("not really ogg"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	apePath := filepath.Join(albumDir, "tagged.ape")
-	if err := os.WriteFile(apePath, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if err := WriteAPETags(apePath, &APETag{Items: AudioMetadataToAPEItems(&AudioMetadata{
-		Title:       "Tagged",
-		Artist:      "APE Artist",
-		Album:       "APE Album",
-		TrackNumber: 2,
-		TotalTracks: 3,
-		Date:        "2026",
-		Genre:       "Pop",
-		Composer:    "Composer",
-	})}); err != nil {
-		t.Fatalf("write ape tags: %v", err)
-	}
-	cuePath, _ := writeExportCueFixture(t, albumDir)
-	if err := os.WriteFile(filepath.Join(albumDir, "ignored.txt"), []byte("ignore"), 0600); err != nil {
-		t.Fatal(err)
-	}
-
-	files, err := collectLibraryAudioFiles(dir, make(chan struct{}))
-	if err != nil {
-		t.Fatalf("collectLibraryAudioFiles: %v", err)
-	}
-	if len(files) < 4 {
-		t.Fatalf("files = %#v", files)
-	}
-	cancelCh := make(chan struct{})
-	close(cancelCh)
-	if _, err := collectLibraryAudioFiles(dir, cancelCh); err == nil {
-		t.Fatal("expected cancelled collect")
-	}
-
-	jsonText, err := ScanLibraryFolder(dir)
-	if err != nil {
-		t.Fatalf("ScanLibraryFolder: %v", err)
-	}
-	var results []LibraryScanResult
-	if err := json.Unmarshal([]byte(jsonText), &results); err != nil {
-		t.Fatalf("decode scan results: %v", err)
-	}
-	if len(results) < 4 {
-		t.Fatalf("scan results = %#v", results)
-	}
-	foundTagged := false
-	for _, result := range results {
-		if result.FilePath == apePath {
-			foundTagged = result.TrackName == "Tagged" && result.ArtistName == "APE Artist"
-		}
-	}
-	if !foundTagged {
-		t.Fatalf("tagged APE not found in %#v", results)
-	}
-	if progress := GetLibraryScanProgress(); !strings.Contains(progress, `"IsComplete":true`) && !strings.Contains(progress, `"is_complete":true`) {
-		t.Fatalf("progress = %s", progress)
-	}
-
-	metaJSON, err := ReadAudioMetadataWithDisplayName(mp3Path, "Display Artist - Display Song.mp3")
-	if err != nil {
-		t.Fatalf("ReadAudioMetadataWithDisplayName: %v", err)
-	}
-	if !strings.Contains(metaJSON, "Display Song") {
-		t.Fatalf("metadata json = %s", metaJSON)
-	}
-	noExtPath := filepath.Join(albumDir, "noext")
-	if err := os.WriteFile(noExtPath, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	noExtJSON, err := ReadAudioMetadataWithDisplayNameAndCoverCacheKey(noExtPath, "Artist - No Ext.mp3", "cache-key")
-	if err != nil {
-		t.Fatalf("ReadAudioMetadataWithDisplayNameAndCoverCacheKey: %v", err)
-	}
-	if !strings.Contains(noExtJSON, "No Ext") {
-		t.Fatalf("no ext metadata = %s", noExtJSON)
-	}
-
-	existing := map[string]int64{}
-	for _, file := range files {
-		existing[file.path] = file.modTime
-	}
-	if info, err := os.Stat(cuePath); err == nil {
-		existing[cuePath+"#track01"] = info.ModTime().UnixMilli()
-	}
-	incJSON, err := scanLibraryFolderIncrementalWithExistingFiles(dir, existing)
-	if err != nil {
-		t.Fatalf("incremental existing: %v", err)
-	}
-	var inc IncrementalScanResult
-	if err := json.Unmarshal([]byte(incJSON), &inc); err != nil {
-		t.Fatalf("decode incremental: %v", err)
-	}
-	if inc.SkippedCount == 0 {
-		t.Fatalf("incremental = %#v", inc)
-	}
-	if _, err := ScanLibraryFolderIncremental("", "{}"); err == nil {
-		t.Fatal("expected empty incremental folder error")
-	}
-	if incJSON, err := ScanLibraryFolderIncremental(dir, `not-json`); err != nil || incJSON == "" {
-		t.Fatalf("incremental invalid existing JSON = %q/%v", incJSON, err)
-	}
-
-	snapshot := filepath.Join(dir, "snapshot.txt")
-	if err := os.WriteFile(snapshot, []byte("bad\n123\t"+mp3Path+"\nnotint\tpath\n999\t"+filepath.Join(dir, "deleted.mp3")+"\n"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	fromSnapshot, err := ScanLibraryFolderIncrementalFromSnapshot(dir, snapshot)
-	if err != nil {
-		t.Fatalf("snapshot incremental: %v", err)
-	}
-	if !strings.Contains(fromSnapshot, "deleted.mp3") {
-		t.Fatalf("snapshot result = %s", fromSnapshot)
-	}
-	if _, err := ScanLibraryFolder(""); err == nil {
-		t.Fatal("expected empty folder scan error")
-	}
-	fileInsteadOfFolder := filepath.Join(dir, "file.flac")
-	if err := os.WriteFile(fileInsteadOfFolder, []byte("audio"), 0600); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := ScanLibraryFolder(fileInsteadOfFolder); err == nil {
-		t.Fatal("expected not folder error")
-	}
-	CancelLibraryScan()
-	SetLibraryCoverCacheDir("")
-}

go_backend/log_progress_timeout_supplement_test.go

@@ -1,123 +0,0 @@
-package gobackend
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"strings"
-	"testing"
-	"time"
-
-	"github.com/dop251/goja"
-)
-
-func TestLogBufferExportedHelpersAndRedaction(t *testing.T) {
-	ClearLogs()
-	SetLoggingEnabled(false)
-	LogInfo("test", "ignored access_token=secret")
-	LogError("test", "Authorization: Bearer secret-token api_key=value")
-	if GetLogCount() != 1 {
-		t.Fatalf("disabled logging should keep errors only, got %d", GetLogCount())
-	}
-
-	SetLoggingEnabled(true)
-	defer SetLoggingEnabled(false)
-	LogDebug("debug", "client_secret=secret")
-	LogWarn("warn", "warning password=secret")
-	GoLog("[GoTag] success token=abc")
-
-	var entries []LogEntry
-	if err := json.Unmarshal([]byte(GetLogs()), &entries); err != nil {
-		t.Fatalf("GetLogs JSON: %v", err)
-	}
-	if len(entries) < 4 {
-		t.Fatalf("expected log entries, got %#v", entries)
-	}
-	for _, entry := range entries {
-		if strings.Contains(entry.Message, "secret-token") || strings.Contains(entry.Message, "api_key=value") || strings.Contains(entry.Message, "password=secret") {
-			t.Fatalf("log was not redacted: %#v", entry)
-		}
-	}
-
-	sinceJSON := GetLogsSince(1)
-	if !strings.Contains(sinceJSON, `"next_index"`) || !strings.Contains(sinceJSON, `"logs"`) {
-		t.Fatalf("GetLogsSince = %q", sinceJSON)
-	}
-	if emptyJSON := GetLogsSince(999); !strings.Contains(emptyJSON, `"logs":[]`) {
-		t.Fatalf("GetLogsSince empty = %q", emptyJSON)
-	}
-	if negativeJSON := GetLogsSince(-5); !strings.Contains(negativeJSON, `"logs"`) {
-		t.Fatalf("GetLogsSince negative = %q", negativeJSON)
-	}
-
-	ClearLogs()
-	if GetLogCount() != 0 || GetLogs() != "[]" {
-		t.Fatalf("logs were not cleared: count=%d logs=%s", GetLogCount(), GetLogs())
-	}
-}
-
-func TestProgressItemHelpersAndWriter(t *testing.T) {
-	ClearAllItemProgress()
-	itemID := "progress-writer"
-	StartItemProgress(itemID)
-	SetItemBytesTotal(itemID, int64(progressUpdateThreshold*2))
-	SetItemBytesReceived(itemID, int64(progressUpdateThreshold))
-
-	progressJSON := GetItemProgress(itemID)
-	if !strings.Contains(progressJSON, `"bytes_received":131072`) || !strings.Contains(progressJSON, `"progress":0.5`) {
-		t.Fatalf("GetItemProgress = %q", progressJSON)
-	}
-	if missing := GetItemProgress("missing"); missing != "{}" {
-		t.Fatalf("missing progress = %q", missing)
-	}
-
-	var out bytes.Buffer
-	writer := NewItemProgressWriter(&out, itemID)
-	payload := bytes.Repeat([]byte("x"), progressUpdateThreshold+1)
-	n, err := writer.Write(payload)
-	if err != nil || n != len(payload) {
-		t.Fatalf("progress writer = %d/%v", n, err)
-	}
-	if out.Len() != len(payload) {
-		t.Fatalf("writer output length = %d", out.Len())
-	}
-	if progressJSON = GetItemProgress(itemID); !strings.Contains(progressJSON, `"bytes_received":131073`) {
-		t.Fatalf("progress after writer = %q", progressJSON)
-	}
-
-	cancelDownload(itemID)
-	defer clearDownloadCancel(itemID)
-	n, err = writer.Write([]byte("cancelled"))
-	if n != 0 || !errors.Is(err, ErrDownloadCancelled) {
-		t.Fatalf("cancelled writer = %d/%v", n, err)
-	}
-
-	ClearAllItemProgress()
-}
-
-func TestRunWithTimeoutBranches(t *testing.T) {
-	if _, err := RunWithTimeout(nil, "1 + 1", time.Millisecond); err == nil {
-		t.Fatal("expected nil VM error")
-	}
-
-	vm := goja.New()
-	value, err := RunWithTimeout(vm, "1 + 2", time.Second)
-	if err != nil || value.ToInteger() != 3 {
-		t.Fatalf("RunWithTimeout success = %v/%v", value, err)
-	}
-
-	timeoutVM := goja.New()
-	_, err = RunWithTimeoutAndRecover(timeoutVM, "for (;;) {}", 10*time.Millisecond)
-	if err == nil {
-		t.Fatal("expected timeout error")
-	}
-	if !IsTimeoutError(&JSExecutionError{Message: "timeout", IsTimeout: true}) {
-		t.Fatal("JSExecutionError should be recognized as timeout")
-	}
-	if IsTimeoutError(errors.New("plain")) {
-		t.Fatal("plain error should not be timeout")
-	}
-	if (&JSExecutionError{Message: "boom"}).Error() != "boom" {
-		t.Fatal("JSExecutionError Error mismatch")
-	}
-}

go_backend/logbuffer.go

@@ -51,7 +51,7 @@ func GetLogBuffer() *LogBuffer {
 		globalLogBuffer = &LogBuffer{
 			entries:        make([]LogEntry, 0, defaultLogBufferSize),
 			maxSize:        defaultLogBufferSize,
-			loggingEnabled: false,
+			loggingEnabled: false, // Default: disabled for performance (user can enable in settings)
 		}
 	})
 	return globalLogBuffer
@@ -145,10 +145,13 @@ func LogError(tag, format string, args ...interface{}) {
 	GetLogBuffer().Add("ERROR", tag, fmt.Sprintf(format, args...))
 }
 
+// GoLog is a drop-in replacement for fmt.Printf that also logs to buffer
+// It parses the tag from the format string if it starts with [Tag]
 func GoLog(format string, args ...interface{}) {
 	message := fmt.Sprintf(format, args...)
 	message = strings.TrimSuffix(message, "\n")
 
+	// Extract tag from message if present (e.g., "[Tidal] message")
 	tag := "Go"
 	level := "INFO"
 
@@ -160,6 +163,7 @@ func GoLog(format string, args ...interface{}) {
 		}
 	}
 
+	// Determine level from message content
 	msgLower := strings.ToLower(message)
 	if strings.Contains(msgLower, "error") || strings.Contains(msgLower, "failed") {
 		level = "ERROR"

go_backend/lyrics.go

@@ -3,6 +3,7 @@ package gobackend
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"math"
 	"net/http"
 	"net/url"
@@ -20,7 +21,9 @@ const (
 	durationToleranceSec = 10.0
 )
 
+// Lyrics provider names (used in settings and cascade ordering)
 const (
+	LyricsProviderSpotifyAPI = "spotify_api"
 	LyricsProviderLRCLIB     = "lrclib"
 	LyricsProviderNetease    = "netease"
 	LyricsProviderMusixmatch = "musixmatch"
@@ -28,42 +31,28 @@ const (
 	LyricsProviderQQMusic    = "qqmusic"
 )
 
+// DefaultLyricsProviders is the default cascade order for lyrics fetching.
+// LRCLIB first (no proxy dependency), then the others.
 var DefaultLyricsProviders = []string{
 	LyricsProviderLRCLIB,
+	LyricsProviderSpotifyAPI,
+	LyricsProviderMusixmatch,
+	LyricsProviderNetease,
 	LyricsProviderAppleMusic,
+	LyricsProviderQQMusic,
 }
 
 var (
 	lyricsProvidersMu sync.RWMutex
 	lyricsProviders   []string // ordered list of enabled providers
-	appVersionMu      sync.RWMutex
-	appVersion        string
 )
 
-func SetAppVersion(version string) {
-	normalized := strings.TrimSpace(version)
-
-	appVersionMu.Lock()
-	defer appVersionMu.Unlock()
-	appVersion = normalized
-}
-
-func GetAppVersion() string {
-	appVersionMu.RLock()
-	defer appVersionMu.RUnlock()
-	return appVersion
-}
-
-func appUserAgent() string {
-	version := GetAppVersion()
-
-	if version == "" {
-		return "SpotiFLAC-Mobile"
-	}
-
-	return "SpotiFLAC-Mobile/" + version
-}
+var (
+	spotifyLyricsRateLimitMu    sync.RWMutex
+	spotifyLyricsRateLimitedTil time.Time
+)
 
+// LyricsFetchOptions controls optional provider-specific enhancements.
 type LyricsFetchOptions struct {
 	IncludeTranslationNetease  bool   `json:"include_translation_netease"`
 	IncludeRomanizationNetease bool   `json:"include_romanization_netease"`
@@ -78,13 +67,13 @@ var defaultLyricsFetchOptions = LyricsFetchOptions{
 	MusixmatchLanguage:         "",
 }
 
-var instrumentalTrackPattern = regexp.MustCompile(`(?i)(?:^|[\s\[(\-])(?:instrumental|inst\.?)(?:[\s\])]|$)`)
-
 var (
 	lyricsFetchOptionsMu sync.RWMutex
 	lyricsFetchOptions   = defaultLyricsFetchOptions
 )
 
+// SetLyricsProviderOrder sets the ordered list of lyrics providers to try.
+// Providers not in the list are disabled. An empty list resets to defaults.
 func SetLyricsProviderOrder(providers []string) {
 	lyricsProvidersMu.Lock()
 	defer lyricsProvidersMu.Unlock()
@@ -95,6 +84,7 @@ func SetLyricsProviderOrder(providers []string) {
 	}
 
 	validNames := map[string]bool{
+		LyricsProviderSpotifyAPI: true,
 		LyricsProviderLRCLIB:     true,
 		LyricsProviderNetease:    true,
 		LyricsProviderMusixmatch: true,
@@ -129,6 +119,7 @@ func GetLyricsProviderOrder() []string {
 
 func GetAvailableLyricsProviders() []map[string]interface{} {
 	return []map[string]interface{}{
+		{"id": LyricsProviderSpotifyAPI, "name": "Spotify Lyrics API", "has_proxy_dependency": true, "description": "Spotify-sourced lyrics via Paxsenix"},
 		{"id": LyricsProviderLRCLIB, "name": "LRCLIB", "has_proxy_dependency": false, "description": "Open-source synced lyrics database"},
 		{"id": LyricsProviderNetease, "name": "Netease", "has_proxy_dependency": true, "description": "NetEase Cloud Music lyrics via Paxsenix"},
 		{"id": LyricsProviderMusixmatch, "name": "Musixmatch", "has_proxy_dependency": true, "description": "Musixmatch lyrics via Paxsenix"},
@@ -258,6 +249,18 @@ type LRCLibResponse struct {
 	SyncedLyrics string  `json:"syncedLyrics"`
 }
 
+type SpotifyLyricsLine struct {
+	TimeTag string `json:"timeTag"`
+	Words   string `json:"words"`
+}
+
+type SpotifyLyricsAPIResponse struct {
+	Error    bool                `json:"error"`
+	Message  string              `json:"message"`
+	SyncType string              `json:"syncType"`
+	Lines    []SpotifyLyricsLine `json:"lines"`
+}
+
 type LyricsLine struct {
 	StartTimeMs int64  `json:"startTimeMs"`
 	Words       string `json:"words"`
@@ -365,6 +368,214 @@ func (c *LyricsClient) FetchLyricsFromLRCLibSearch(query string, durationSec flo
 	return c.parseLRCLibResponse(&results[0]), nil
 }
 
+func parseSpotifyLyricsTimeTagToMs(tag string) int64 {
+	raw := strings.TrimSpace(tag)
+	raw = strings.TrimPrefix(raw, "[")
+	raw = strings.TrimSuffix(raw, "]")
+	if raw == "" {
+		return 0
+	}
+
+	if ms, err := strconv.ParseInt(raw, 10, 64); err == nil {
+		return ms
+	}
+
+	re := regexp.MustCompile(`^(\d{1,2}):(\d{2})\.(\d{1,3})$`)
+	matches := re.FindStringSubmatch(raw)
+	if len(matches) != 4 {
+		return 0
+	}
+
+	minutes, _ := strconv.ParseInt(matches[1], 10, 64)
+	seconds, _ := strconv.ParseInt(matches[2], 10, 64)
+	fraction := matches[3]
+	fractionInt, _ := strconv.ParseInt(fraction, 10, 64)
+	if len(fraction) == 2 {
+		fractionInt *= 10
+	} else if len(fraction) == 1 {
+		fractionInt *= 100
+	}
+	return minutes*60*1000 + seconds*1000 + fractionInt
+}
+
+func getSpotifyLyricsRateLimitUntil() time.Time {
+	spotifyLyricsRateLimitMu.RLock()
+	defer spotifyLyricsRateLimitMu.RUnlock()
+	return spotifyLyricsRateLimitedTil
+}
+
+func setSpotifyLyricsRateLimitUntil(until time.Time) {
+	spotifyLyricsRateLimitMu.Lock()
+	spotifyLyricsRateLimitedTil = until
+	spotifyLyricsRateLimitMu.Unlock()
+}
+
+func parseSpotifyRetryAfter(retryAfter string, now time.Time) time.Time {
+	raw := strings.TrimSpace(retryAfter)
+	if raw == "" {
+		return now.Add(10 * time.Minute)
+	}
+
+	if sec, err := strconv.Atoi(raw); err == nil && sec > 0 {
+		return now.Add(time.Duration(sec) * time.Second)
+	}
+
+	if when, err := http.ParseTime(raw); err == nil && when.After(now) {
+		return when
+	}
+
+	return now.Add(10 * time.Minute)
+}
+
+func buildSpotifyLyricsResponse(lines []LyricsLine, syncType, plainLyrics string) (*LyricsResponse, error) {
+	if len(lines) == 0 {
+		return nil, fmt.Errorf("Spotify Lyrics API returned empty lines")
+	}
+	if syncType == "" {
+		if len(lines) > 0 && lines[0].StartTimeMs > 0 {
+			syncType = "LINE_SYNCED"
+		} else {
+			syncType = "UNSYNCED"
+		}
+	}
+	return &LyricsResponse{
+		Lines:        lines,
+		SyncType:     syncType,
+		Instrumental: false,
+		PlainLyrics:  plainLyrics,
+		Provider:     "Spotify Lyrics API",
+		Source:       "Spotify Lyrics API",
+	}, nil
+}
+
+func plainLyricsFromTimedLines(lines []LyricsLine) string {
+	parts := make([]string, 0, len(lines))
+	for _, line := range lines {
+		words := strings.TrimSpace(line.Words)
+		if words == "" {
+			continue
+		}
+		parts = append(parts, words)
+	}
+	return strings.Join(parts, "\n")
+}
+
+func parseSpotifyLyricsResponseBody(body []byte) (*LyricsResponse, error) {
+	var lrcPayload string
+	if err := json.Unmarshal(body, &lrcPayload); err == nil {
+		trimmed := strings.TrimSpace(lrcPayload)
+		if trimmed == "" {
+			return nil, fmt.Errorf("Spotify Lyrics API returned empty payload")
+		}
+
+		lines := parseSyncedLyrics(trimmed)
+		if len(lines) > 0 {
+			return buildSpotifyLyricsResponse(lines, "LINE_SYNCED", plainLyricsFromTimedLines(lines))
+		}
+
+		plainLines := plainTextLyricsLines(trimmed)
+		return buildSpotifyLyricsResponse(plainLines, "UNSYNCED", trimmed)
+	}
+
+	var apiResp SpotifyLyricsAPIResponse
+	if err := json.Unmarshal(body, &apiResp); err != nil {
+		return nil, fmt.Errorf("failed to parse Spotify Lyrics API response: %w", err)
+	}
+
+	if apiResp.Error {
+		msg := strings.TrimSpace(apiResp.Message)
+		if msg == "" {
+			msg = "Spotify Lyrics API returned error"
+		}
+		return nil, fmt.Errorf("%s", msg)
+	}
+
+	lines := make([]LyricsLine, 0, len(apiResp.Lines))
+	for _, line := range apiResp.Lines {
+		words := strings.TrimSpace(line.Words)
+		if words == "" {
+			continue
+		}
+		startMs := parseSpotifyLyricsTimeTagToMs(line.TimeTag)
+		lines = append(lines, LyricsLine{
+			StartTimeMs: startMs,
+			Words:       words,
+			EndTimeMs:   0,
+		})
+	}
+
+	for i := 0; i < len(lines)-1; i++ {
+		nextStart := lines[i+1].StartTimeMs
+		if nextStart > lines[i].StartTimeMs {
+			lines[i].EndTimeMs = nextStart
+		}
+	}
+	if len(lines) > 0 {
+		last := len(lines) - 1
+		if lines[last].EndTimeMs == 0 {
+			lines[last].EndTimeMs = lines[last].StartTimeMs + 5000
+		}
+	}
+
+	return buildSpotifyLyricsResponse(lines, apiResp.SyncType, plainLyricsFromTimedLines(lines))
+}
+
+func (c *LyricsClient) FetchLyricsFromSpotifyAPI(spotifyID string) (*LyricsResponse, error) {
+	now := time.Now()
+	if limitedUntil := getSpotifyLyricsRateLimitUntil(); limitedUntil.After(now) {
+		waitFor := int(math.Ceil(limitedUntil.Sub(now).Seconds()))
+		return nil, fmt.Errorf(
+			"Spotify Lyrics API cooldown active (%ds remaining after previous 429)",
+			waitFor,
+		)
+	}
+
+	spotifyID = strings.TrimSpace(spotifyID)
+	if spotifyID == "" {
+		return nil, fmt.Errorf("spotify ID is empty")
+	}
+	if parsed, err := parseSpotifyURI(spotifyID); err == nil && parsed.Type == "track" && parsed.ID != "" {
+		spotifyID = parsed.ID
+	}
+
+	apiURL := fmt.Sprintf("https://lyrics.paxsenix.org/spotify/lyrics?id=%s", url.QueryEscape(spotifyID))
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch from Spotify Lyrics API: %w", err)
+	}
+	defer resp.Body.Close()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read Spotify Lyrics API response: %w", err)
+	}
+
+	if resp.StatusCode != 200 {
+		if resp.StatusCode == http.StatusTooManyRequests {
+			retryUntil := parseSpotifyRetryAfter(resp.Header.Get("Retry-After"), now)
+			setSpotifyLyricsRateLimitUntil(retryUntil)
+		}
+		var payload map[string]interface{}
+		if err := json.Unmarshal(bodyBytes, &payload); err == nil {
+			if msg, ok := payload["message"].(string); ok && strings.TrimSpace(msg) != "" {
+				return nil, fmt.Errorf("Spotify Lyrics API returned status %d: %s", resp.StatusCode, strings.TrimSpace(msg))
+			}
+			if msg, ok := payload["error"].(string); ok && strings.TrimSpace(msg) != "" {
+				return nil, fmt.Errorf("Spotify Lyrics API returned status %d: %s", resp.StatusCode, strings.TrimSpace(msg))
+			}
+		}
+		return nil, fmt.Errorf("Spotify Lyrics API returned status %d", resp.StatusCode)
+	}
+
+	return parseSpotifyLyricsResponseBody(bodyBytes)
+}
+
 func (c *LyricsClient) findBestMatch(results []LRCLibResponse, targetDurationSec float64) *LRCLibResponse {
 	var bestSynced *LRCLibResponse
 	var bestPlain *LRCLibResponse
@@ -389,18 +600,6 @@ func (c *LyricsClient) findBestMatch(results []LRCLibResponse, targetDurationSec
 	return bestPlain
 }
 
-func plainLyricsFromTimedLines(lines []LyricsLine) string {
-	parts := make([]string, 0, len(lines))
-	for _, line := range lines {
-		words := strings.TrimSpace(line.Words)
-		if words == "" {
-			continue
-		}
-		parts = append(parts, words)
-	}
-	return strings.Join(parts, "\n")
-}
-
 func (c *LyricsClient) durationMatches(lrcDuration, targetDuration float64) bool {
 	diff := math.Abs(lrcDuration - targetDuration)
 	return diff <= durationToleranceSec
@@ -410,18 +609,8 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 	primaryArtist := normalizeArtistName(artistName)
 	fetchOptions := GetLyricsFetchOptions()
 
-	if isLikelyInstrumentalTrack(trackName) {
-		GoLog("[Lyrics] Track marked instrumental by title heuristic, skipping lyrics search: %s - %s\n", artistName, trackName)
-		instrumental := &LyricsResponse{
-			Instrumental: true,
-			Source:       "Heuristic: Instrumental",
-		}
-		globalLyricsCache.Set(artistName, trackName, durationSec, instrumental)
-		return instrumental, nil
-	}
-
-	extManager := getExtensionManager()
-	var extensionProviders []*extensionProviderWrapper
+	extManager := GetExtensionManager()
+	var extensionProviders []*ExtensionProviderWrapper
 	if extManager != nil {
 		extensionProviders = extManager.GetLyricsProviders()
 	}
@@ -480,6 +669,9 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 		var err error
 
 		switch providerName {
+		case LyricsProviderSpotifyAPI:
+			lyrics, err = c.FetchLyricsFromSpotifyAPI(spotifyID)
+
 		case LyricsProviderLRCLIB:
 			lyrics, err = c.tryLRCLIB(primaryArtist, artistName, trackName, simplifiedTrack, durationSec)
 
@@ -561,16 +753,19 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 	return nil, fmt.Errorf("lyrics not found from any source")
 }
 
+// tryLRCLIB attempts all LRCLIB search strategies (exact match, simplified, search).
 func (c *LyricsClient) tryLRCLIB(primaryArtist, artistName, trackName, simplifiedTrack string, durationSec float64) (*LyricsResponse, error) {
 	var lyrics *LyricsResponse
 	var err error
 
+	// 1. Exact match with primary artist
 	lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, trackName)
 	if err == nil && lyrics != nil && (len(lyrics.Lines) > 0 || lyrics.Instrumental) {
 		lyrics.Source = "LRCLIB"
 		return lyrics, nil
 	}
 
+	// 2. Exact match with full artist name
 	if primaryArtist != artistName {
 		lyrics, err = c.FetchLyricsWithMetadata(artistName, trackName)
 		if err == nil && lyrics != nil && (len(lyrics.Lines) > 0 || lyrics.Instrumental) {
@@ -579,6 +774,7 @@ func (c *LyricsClient) tryLRCLIB(primaryArtist, artistName, trackName, simplifie
 		}
 	}
 
+	// 3. Simplified track name
 	if simplifiedTrack != trackName {
 		lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, simplifiedTrack)
 		if err == nil && lyrics != nil && (len(lyrics.Lines) > 0 || lyrics.Instrumental) {
@@ -587,6 +783,7 @@ func (c *LyricsClient) tryLRCLIB(primaryArtist, artistName, trackName, simplifie
 		}
 	}
 
+	// 4. Search by query
 	query := primaryArtist + " " + trackName
 	lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
 	if err == nil && lyrics != nil && (len(lyrics.Lines) > 0 || lyrics.Instrumental) {
@@ -594,6 +791,7 @@ func (c *LyricsClient) tryLRCLIB(primaryArtist, artistName, trackName, simplifie
 		return lyrics, nil
 	}
 
+	// 5. Search with simplified track name
 	if simplifiedTrack != trackName {
 		query = primaryArtist + " " + simplifiedTrack
 		lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
@@ -711,6 +909,8 @@ func lyricsHasUsableText(lyrics *LyricsResponse) bool {
 	return false
 }
 
+// detectLyricsErrorPayload extracts human-readable error messages from
+// JSON payloads returned by lyrics proxies when no lyric is available.
 func detectLyricsErrorPayload(raw string) (string, bool) {
 	trimmed := strings.TrimSpace(raw)
 	if trimmed == "" || !strings.HasPrefix(trimmed, "{") {
@@ -835,6 +1035,8 @@ func simplifyTrackName(name string) string {
 		return result
 	}
 
+	// Add a loose fallback form for provider queries where punctuation
+	// and separators differ (e.g. "/" vs "_" vs spaces).
 	if loose := normalizeLooseTitle(result); loose != "" {
 		return loose
 	}
@@ -856,15 +1058,6 @@ func normalizeArtistName(name string) string {
 	return strings.TrimSpace(result)
 }
 
-func isLikelyInstrumentalTrack(name string) bool {
-	trimmed := strings.TrimSpace(name)
-	if trimmed == "" {
-		return false
-	}
-
-	return instrumentalTrackPattern.MatchString(trimmed)
-}
-
 func SaveLRCFile(audioFilePath, lrcContent string) (string, error) {
 	if lrcContent == "" {
 		return "", fmt.Errorf("empty LRC content")

go_backend/lyrics_apple.go

@@ -11,6 +11,8 @@ import (
 	"time"
 )
 
+// AppleMusicClient fetches lyrics from Apple Music.
+// Uses Paxsenix endpoints for search and lyrics.
 type AppleMusicClient struct {
 	httpClient *http.Client
 }
@@ -23,6 +25,7 @@ type appleMusicSearchResult struct {
 	Duration   int    `json:"duration"`
 }
 
+// PaxResponse represents the lyrics proxy response for word-by-word / line lyrics
 type paxResponse struct {
 	Type    string      `json:"type"`    // "Syllable" or "Line"
 	Content []paxLyrics `json:"content"` // List of lyric lines
@@ -100,6 +103,7 @@ func selectBestAppleMusicSearchResult(results []appleMusicSearchResult, trackNam
 	return &results[bestIndex]
 }
 
+// SearchSong searches for a song on Apple Music and returns its ID.
 func (c *AppleMusicClient) SearchSong(trackName, artistName string, durationSec float64) (string, error) {
 	query := trackName + " " + artistName
 	if strings.TrimSpace(query) == "" {
@@ -114,7 +118,7 @@ func (c *AppleMusicClient) SearchSong(trackName, artistName string, durationSec
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
 
-	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("User-Agent", getRandomUserAgent())
 	req.Header.Set("Accept", "application/json")
 
 	resp, err := c.httpClient.Do(req)
@@ -140,6 +144,7 @@ func (c *AppleMusicClient) SearchSong(trackName, artistName string, durationSec
 	return strings.TrimSpace(best.ID), nil
 }
 
+// FetchLyricsByID fetches lyrics from the paxsenix proxy using Apple Music song ID.
 func (c *AppleMusicClient) FetchLyricsByID(songID string) (string, error) {
 	lyricsURL := fmt.Sprintf("https://lyrics.paxsenix.org/apple-music/lyrics?id=%s", songID)
 
@@ -147,8 +152,7 @@ func (c *AppleMusicClient) FetchLyricsByID(songID string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
-	req.Header.Set("User-Agent", appUserAgent())
-	req.Header.Set("Accept", "application/json")
+	req.Header.Set("User-Agent", getRandomUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
@@ -248,6 +252,7 @@ func formatPaxContent(lyricsType string, content []paxLyrics, multiPersonWordByW
 	return strings.TrimSpace(sb.String())
 }
 
+// FetchLyrics searches Apple Music and returns parsed LyricsResponse.
 func (c *AppleMusicClient) FetchLyrics(
 	trackName,
 	artistName string,
@@ -267,8 +272,10 @@ func (c *AppleMusicClient) FetchLyrics(
 		return nil, fmt.Errorf("apple music proxy returned non-lyric payload: %s", errMsg)
 	}
 
+	// Try to parse as pax format (word-by-word or line)
 	lrcText, err := formatPaxLyricsToLRC(rawLyrics, multiPersonWordByWord)
 	if err != nil {
+		// If pax parsing fails, try to parse as direct LRC text
 		lrcText = rawLyrics
 	}
 
@@ -282,6 +289,7 @@ func (c *AppleMusicClient) FetchLyrics(
 		}, nil
 	}
 
+	// Fall back to plain text if no timestamps found
 	resultLines := plainTextLyricsLines(lrcText)
 
 	if len(resultLines) > 0 {

go_backend/lyrics_musixmatch.go

@@ -11,11 +11,39 @@ import (
 	"time"
 )
 
+// MusixmatchClient fetches lyrics from Musixmatch via a proxy server.
+// The proxy handles Musixmatch authentication internally.
 type MusixmatchClient struct {
 	httpClient *http.Client
 	baseURL    string
 }
 
+type musixmatchSearchResponse struct {
+	ID                 int64                     `json:"id"`
+	SongName           string                    `json:"songName"`
+	ArtistName         string                    `json:"artistName"`
+	AlbumName          string                    `json:"albumName"`
+	Artwork            string                    `json:"artwork"`
+	ReleaseDate        string                    `json:"releaseDate"`
+	Duration           int                       `json:"duration"`
+	URL                string                    `json:"url"`
+	AlbumID            int64                     `json:"albumId"`
+	HasSyncedLyrics    bool                      `json:"hasSyncedLyrics"`
+	HasUnsyncedLyrics  bool                      `json:"hasUnsyncedLyrics"`
+	AvailableLanguages []string                  `json:"availableLanguages"`
+	OriginalLanguage   string                    `json:"originalLanguage"`
+	SyncedLyrics       *musixmatchLyricsResponse `json:"syncedLyrics"`
+	UnsyncedLyrics     *musixmatchLyricsResponse `json:"unsyncedLyrics"`
+}
+
+type musixmatchLyricsResponse struct {
+	ID          int64  `json:"id"`
+	Duration    int    `json:"duration"`
+	Language    string `json:"language"`
+	UpdatedTime string `json:"updatedTime"`
+	Lyrics      string `json:"lyrics"`
+}
+
 func NewMusixmatchClient() *MusixmatchClient {
 	return &MusixmatchClient{
 		httpClient: NewMetadataHTTPClient(15 * time.Second),
@@ -46,7 +74,7 @@ func (c *MusixmatchClient) fetchLyricsPayload(trackName, artistName string, dura
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
 	req.Header.Set("Accept", "application/json")
-	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("User-Agent", getRandomUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
@@ -86,6 +114,7 @@ func (c *MusixmatchClient) fetchLyricsPayload(trackName, artistName string, dura
 	return "", fmt.Errorf("failed to decode musixmatch response")
 }
 
+// FetchLyricsInLanguage retrieves lyrics from Musixmatch for a specific language code.
 func (c *MusixmatchClient) FetchLyricsInLanguage(trackName, artistName string, durationSec float64, language string) (*LyricsResponse, error) {
 	lang := strings.ToLower(strings.TrimSpace(language))
 	if lang == "" {
@@ -122,6 +151,7 @@ func (c *MusixmatchClient) FetchLyricsInLanguage(trackName, artistName string, d
 	return nil, fmt.Errorf("no lyrics found on musixmatch for language %s", lang)
 }
 
+// FetchLyrics searches Musixmatch and returns parsed LyricsResponse.
 func (c *MusixmatchClient) FetchLyrics(trackName, artistName string, durationSec float64, preferredLanguage string) (*LyricsResponse, error) {
 	if preferred := strings.ToLower(strings.TrimSpace(preferredLanguage)); preferred != "" {
 		localized, localizedErr := c.FetchLyricsInLanguage(trackName, artistName, durationSec, preferred)

go_backend/lyrics_netease.go

@@ -9,6 +9,7 @@ import (
 	"time"
 )
 
+// NeteaseClient fetches lyrics through Paxsenix's NetEase endpoints.
 type NeteaseClient struct {
 	httpClient *http.Client
 }
@@ -50,6 +51,7 @@ func NewNeteaseClient() *NeteaseClient {
 	}
 }
 
+// SearchSong searches for a song on Netease and returns the song ID.
 func (c *NeteaseClient) SearchSong(trackName, artistName string) (int64, error) {
 	query := trackName + " " + artistName
 	if strings.TrimSpace(query) == "" {
@@ -70,7 +72,7 @@ func (c *NeteaseClient) SearchSong(trackName, artistName string) (int64, error)
 	for k, v := range neteaseHeaders {
 		req.Header.Set(k, v)
 	}
-	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("User-Agent", getRandomUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
@@ -94,6 +96,7 @@ func (c *NeteaseClient) SearchSong(trackName, artistName string) (int64, error)
 	return searchResp.Result.Songs[0].ID, nil
 }
 
+// FetchLyricsByID fetches synced lyrics for a given Netease song ID.
 func (c *NeteaseClient) FetchLyricsByID(songID int64, includeTranslation, includeRomanization bool) (string, error) {
 	lyricsURL := "https://lyrics.paxsenix.org/netease/lyrics"
 	params := url.Values{}
@@ -109,7 +112,7 @@ func (c *NeteaseClient) FetchLyricsByID(songID int64, includeTranslation, includ
 	for k, v := range neteaseHeaders {
 		req.Header.Set(k, v)
 	}
-	req.Header.Set("User-Agent", appUserAgent())
+	req.Header.Set("User-Agent", getRandomUserAgent())
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
@@ -143,6 +146,7 @@ func (c *NeteaseClient) FetchLyricsByID(songID int64, includeTranslation, includ
 	return lyric, nil
 }
 
+// FetchLyrics searches for a track and returns parsed LyricsResponse.
 func (c *NeteaseClient) FetchLyrics(
 	trackName,
 	artistName string,
@@ -162,6 +166,7 @@ func (c *NeteaseClient) FetchLyrics(
 
 	lines := parseSyncedLyrics(lrcText)
 	if len(lines) == 0 {
+		// May be plain text lyrics without timestamps
 		plainLines := strings.Split(lrcText, "\n")
 		for _, line := range plainLines {
 			trimmed := strings.TrimSpace(line)