feat: export failed downloads to TXT file

- Add Export button in queue when there are failed downloads
- Add auto-export setting in Download Settings
- Export includes track name, artist, Spotify/Deezer URL, and error message
- Clear Failed action in snackbar after export

CHANGELOG.md

@@ -1,5 +1,26 @@
 # Changelog
 
+## [3.3.5] - 2026-02-01
+
+Same as 3.3.1 but fixes crash issues caused by FFmpeg.
+
+### Added
+
+- **Export Failed Downloads**: Export failed downloads to TXT file for easy lookup on other platforms
+- **Auto-Export Setting**: Option to automatically export failed downloads when queue finishes
+
+### Fixed
+
+- **FFmpeg Crash**: Fixed crash issues during M4A to MP3/Opus conversion
+- **Service Selection Ignored**: Fixed bug where selecting Qobuz/Amazon from service picker was ignored and always used Tidal instead
+- **iOS iCloud Drive Permission Error**: Block iCloud Drive folder selection on iOS (Go backend cannot access iCloud due to sandboxing)
+
+### Changed
+
+- **Amazon Fallback Only**: Amazon Music is now grayed out in service picker and can only be used as fallback provider
+
+---
+
 ## [3.3.1] - 2026-02-01
 
 ### Added

android/app/proguard-rules.pro

@@ -28,6 +28,9 @@
 # FFmpeg Kit
 -keep class com.arthenica.ffmpegkit.** { *; }
 -keep class com.arthenica.smartexception.** { *; }
+# FFmpeg Kit (new fork package)
+-keep class com.antonkarpenko.ffmpegkit.** { *; }
+-keep class com.antonkarpenko.smartexception.** { *; }
 
 # Apache Tika (if used by FFmpeg)
 -dontwarn org.apache.tika.**

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

@@ -6,7 +6,6 @@ import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.embedding.engine.FlutterShellArgs
 import io.flutter.plugin.common.MethodChannel
-import io.flutter.plugins.GeneratedPluginRegistrant
 import gobackend.Gobackend
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -158,7 +157,6 @@ class MainActivity: FlutterActivity() {
 
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
-        GeneratedPluginRegistrant.registerWith(flutterEngine)
         
         MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler { call, result ->
             scope.launch {

go_backend/amazon.go

@@ -54,10 +54,7 @@ func NewAmazonDownloader() *AmazonDownloader {
 	return globalAmazonDownloader
 }
 
-// downloadFromAfkarXYZ downloads a track using AfkarXYZ API
-// Returns: downloadURL, fileName, error
 func (a *AmazonDownloader) downloadFromAfkarXYZ(amazonURL string) (string, string, error) {
-	// AfkarXYZ API endpoint
 	apiURL := "https://amazon.afkarxyz.fun/convert?url=" + url.QueryEscape(amazonURL)
 
 	GoLog("[Amazon] Fetching from AfkarXYZ API...\n")
@@ -98,7 +95,6 @@ func (a *AmazonDownloader) downloadFromAfkarXYZ(amazonURL string) (string, strin
 		fileName = "track.flac"
 	}
 
-	// Sanitize filename
 	reg := regexp.MustCompile(`[<>:"/\\|?*]`)
 	fileName = reg.ReplaceAllString(fileName, "")
 
@@ -110,7 +106,6 @@ func (a *AmazonDownloader) downloadFromAfkarXYZ(amazonURL string) (string, strin
 func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
 	ctx := context.Background()
 
-	// Initialize item progress (required for all downloads)
 	if itemID != "" {
 		StartItemProgress(itemID)
 		defer CompleteItemProgress(itemID)
@@ -162,7 +157,6 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 		written, err = io.Copy(bufWriter, resp.Body)
 	}
 
-	// Flush buffer before checking for errors
 	flushErr := bufWriter.Flush()
 	closeErr := out.Close()
 
@@ -182,7 +176,6 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
-	// Verify file size if Content-Length was provided
 	if expectedSize > 0 && written != expectedSize {
 		os.Remove(outputPath)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
@@ -206,7 +199,6 @@ type AmazonDownloadResult struct {
 	ISRC        string
 }
 
-// downloadFromAmazon uses AfkarXYZ API to download from Amazon Music
 func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	downloader := NewAmazonDownloader()
 
@@ -299,6 +291,10 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	existingMeta, metaErr := ReadMetadata(outputPath)
 	actualTrackNum := req.TrackNumber
 	actualDiscNum := req.DiscNumber
+	actualDate := req.ReleaseDate
+	actualAlbum := req.AlbumName
+	actualTitle := req.TrackName
+	actualArtist := req.ArtistName
 
 	if metaErr == nil && existingMeta != nil {
 		if existingMeta.TrackNumber > 0 && (req.TrackNumber == 0 || req.TrackNumber == 1) {
@@ -309,15 +305,24 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 			actualDiscNum = existingMeta.DiscNumber
 			GoLog("[Amazon] Using disc number from file: %d (request had: %d)\n", actualDiscNum, req.DiscNumber)
 		}
+		if existingMeta.Date != "" && req.ReleaseDate == "" {
+			actualDate = existingMeta.Date
+			GoLog("[Amazon] Using release date from file: %s\n", actualDate)
+		}
+		if existingMeta.Album != "" && req.AlbumName == "" {
+			actualAlbum = existingMeta.Album
+			GoLog("[Amazon] Using album from file: %s\n", actualAlbum)
+		}
+		GoLog("[Amazon] Existing metadata - Title: %s, Artist: %s, Album: %s, Date: %s\n",
+			existingMeta.Title, existingMeta.Artist, existingMeta.Album, existingMeta.Date)
 	}
 
-	// Embed metadata using Spotify data
 	metadata := Metadata{
-		Title:       req.TrackName,
+		Title:       actualTitle,
-		Artist:      req.ArtistName,
+		Artist:      actualArtist,
-		Album:       req.AlbumName,
+		Album:       actualAlbum,
 		AlbumArtist: req.AlbumArtist,
-		Date:        req.ReleaseDate,
+		Date:        actualDate,
 		TrackNumber: actualTrackNum,
 		TotalTracks: req.TotalTracks,
 		DiscNumber:  actualDiscNum,
@@ -327,11 +332,18 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 		Copyright:   req.Copyright,
 	}
 
-	// Use cover data from parallel fetch
 	var coverData []byte
-	if parallelResult != nil && parallelResult.CoverData != nil {
+	if parallelResult != nil && parallelResult.CoverData != nil && len(parallelResult.CoverData) > 0 {
 		coverData = parallelResult.CoverData
 		GoLog("[Amazon] Using parallel-fetched cover (%d bytes)\n", len(coverData))
+	} else {
+		existingCover, coverErr := ExtractCoverArt(outputPath)
+		if coverErr == nil && len(existingCover) > 0 {
+			coverData = existingCover
+			GoLog("[Amazon] Using existing cover from Amazon file (%d bytes)\n", len(coverData))
+		} else {
+			GoLog("[Amazon] No cover available (parallel fetch failed and no existing cover)\n")
+		}
 	}
 
 	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
@@ -341,7 +353,7 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
 		lyricsMode := req.LyricsMode
 		if lyricsMode == "" {
-			lyricsMode = "embed" // default
+			lyricsMode = "embed"
 		}
 
 		if lyricsMode == "external" || lyricsMode == "both" {

go_backend/deezer.go

@@ -55,7 +55,7 @@ func GetDeezerClient() *DeezerClient {
 type deezerTrack struct {
 	ID            int64             `json:"id"`
 	Title         string            `json:"title"`
-	Duration      int               `json:"duration"` // in seconds
+	Duration      int               `json:"duration"`
 	TrackPosition int               `json:"track_position"`
 	DiskNumber    int               `json:"disk_number"`
 	ISRC          string            `json:"isrc"`
@@ -121,7 +121,7 @@ func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
 		AlbumArtist: track.Artist.Name,
 		DurationMS:  track.Duration * 1000,
 		Images:      albumImage,
-		ReleaseDate: releaseDate, // Added this
+		ReleaseDate: releaseDate,
 		TrackNumber: track.TrackPosition,
 		DiscNumber:  track.DiskNumber,
 		ExternalURL: track.Link,
@@ -182,15 +182,12 @@ type deezerPlaylistFull struct {
 	} `json:"tracks"`
 }
 
-// NOTE: ISRC is NOT fetched during search for performance - use GetTrackISRC when needed for download
-// filter can be: "" (all), "track", "artist", "album", "playlist"
 func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit, artistLimit int, filter string) (*SearchAllResult, error) {
 	GoLog("[Deezer] SearchAll: query=%q, trackLimit=%d, artistLimit=%d, filter=%q\n", query, trackLimit, artistLimit, filter)
 
-	albumLimit := 5 // Same as artistLimit for consistency
+	albumLimit := 5
 	playlistLimit := 5
 
-	// When filter is specified, increase limits for that type only
 	if filter != "" {
 		switch filter {
 		case "track":
@@ -233,7 +230,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 		Playlists: make([]SearchPlaylistResult, 0, playlistLimit),
 	}
 
-	// Search tracks - NO ISRC fetch for performance
 	if trackLimit > 0 {
 		trackURL := fmt.Sprintf("%s/track?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), trackLimit)
 		GoLog("[Deezer] Fetching tracks from: %s\n", trackURL)
@@ -263,7 +259,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 		}
 	}
 
-	// Search artists
 	if artistLimit > 0 {
 		artistURL := fmt.Sprintf("%s/artist?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), artistLimit)
 		GoLog("[Deezer] Fetching artists from: %s\n", artistURL)
@@ -296,7 +291,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 		}
 	}
 
-	// Search albums
 	if albumLimit > 0 {
 		albumURL := fmt.Sprintf("%s/album?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), albumLimit)
 		GoLog("[Deezer] Fetching albums from: %s\n", albumURL)
@@ -358,7 +352,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 		}
 	}
 
-	// Search playlists
 	if playlistLimit > 0 {
 		playlistURL := fmt.Sprintf("%s/playlist?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), playlistLimit)
 		GoLog("[Deezer] Fetching playlists from: %s\n", playlistURL)
@@ -425,7 +418,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 	return result, nil
 }
 
-// GetTrack fetches a single track by Deezer ID
 func (c *DeezerClient) GetTrack(ctx context.Context, trackID string) (*TrackResponse, error) {
 	trackURL := fmt.Sprintf(deezerTrackURL, trackID)
 
@@ -439,7 +431,6 @@ func (c *DeezerClient) GetTrack(ctx context.Context, trackID string) (*TrackResp
 	}, nil
 }
 
-// ISRC is fetched in parallel for better performance
 func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResponsePayload, error) {
 	c.cacheMu.RLock()
 	if entry, ok := c.albumCache[albumID]; ok && !entry.isExpired() {
@@ -465,7 +456,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 		artistName = strings.Join(names, ", ")
 	}
 
-	// Extract genres as comma-separated string
 	var genres []string
 	for _, g := range album.Genres.Data {
 		if g.Name != "" {
@@ -481,14 +471,12 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 		Artists:     artistName,
 		ArtistId:    fmt.Sprintf("deezer:%d", album.Artist.ID),
 		Images:      albumImage,
-		Genre:       genreStr,    // From Deezer album
+		Genre:       genreStr,
-		Label:       album.Label, // From Deezer album
+		Label:       album.Label,
 	}
 
-	// Fetch all tracks with pagination (Deezer default limit is 25)
 	allTracks := album.Tracks.Data
 
-	// If album has more tracks than returned, fetch remaining pages
 	if album.NbTracks > len(allTracks) {
 		GoLog("[Deezer] Album has %d tracks but only got %d, fetching remaining...", album.NbTracks, len(allTracks))
 
@@ -523,7 +511,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 	isrcMap := c.fetchISRCsParallel(ctx, allTracks)
 
 	tracks := make([]AlbumTrackMetadata, 0, len(allTracks))
-	// Normalize record_type (Deezer uses "compile" instead of "compilation")
 	albumType := album.RecordType
 	if albumType == "compile" {
 		albumType = "compilation"
@@ -533,7 +520,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 		trackIDStr := fmt.Sprintf("%d", track.ID)
 		isrc := isrcMap[trackIDStr]
 
-		// Use track position from API, fallback to index+1 if not provided
 		trackNum := track.TrackPosition
 		if trackNum == 0 {
 			trackNum = i + 1
@@ -581,7 +567,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 	}
 	c.cacheMu.RUnlock()
 
-	// Fetch artist info
 	artistURL := fmt.Sprintf(deezerArtistURL, artistID)
 	var artist deezerArtistFull
 	if err := c.getJSON(ctx, artistURL, &artist); err != nil {
@@ -596,7 +581,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 		Popularity: 0,
 	}
 
-	// Fetch artist albums
 	albumsURL := fmt.Sprintf("%s/albums?limit=100", fmt.Sprintf(deezerArtistURL, artistID))
 	var albumsResp struct {
 		Data []struct {
@@ -608,7 +592,7 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 			CoverMedium string `json:"cover_medium"`
 			CoverBig    string `json:"cover_big"`
 			CoverXL     string `json:"cover_xl"`
-			RecordType  string `json:"record_type"` // album, single, ep, compile
+			RecordType  string `json:"record_type"`
 		} `json:"data"`
 	}
 
@@ -680,10 +664,8 @@ func (c *DeezerClient) GetPlaylist(ctx context.Context, playlistID string) (*Pla
 	info.Owner.Name = playlist.Title
 	info.Owner.Images = playlistImage
 
-	// Fetch all tracks with pagination (Deezer default limit is 25)
 	allTracks := playlist.Tracks.Data
 
-	// If playlist has more tracks than returned, fetch remaining pages
 	if playlist.NbTracks > len(allTracks) {
 		GoLog("[Deezer] Playlist has %d tracks but only got %d, fetching remaining...", playlist.NbTracks, len(allTracks))
 
@@ -789,7 +771,6 @@ func (c *DeezerClient) fetchFullTrack(ctx context.Context, trackID string) (*dee
 	return &track, nil
 }
 
-// fetchISRCsParallel fetches ISRCs for multiple tracks in parallel with caching
 func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTrack) map[string]string {
 	result := make(map[string]string, len(tracks))
 	var resultMu sync.Mutex
@@ -828,7 +809,6 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 		return result
 	}
 
-	// Use semaphore to limit concurrent requests
 	sem := make(chan struct{}, deezerMaxParallelISRC)
 	var wg sync.WaitGroup
 
@@ -850,7 +830,6 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 				return
 			}
 
-			// Store in result and cache
 			resultMu.Lock()
 			result[trackIDStr] = fullTrack.ISRC
 			resultMu.Unlock()
@@ -865,7 +844,6 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 	return result
 }
 
-// Use this when you need ISRC for download
 func (c *DeezerClient) GetTrackISRC(ctx context.Context, trackID string) (string, error) {
 	c.cacheMu.RLock()
 	if isrc, ok := c.isrcCache[trackID]; ok {
@@ -926,11 +904,10 @@ func (c *DeezerClient) getBestAlbumImage(album deezerAlbumFull) string {
 }
 
 type AlbumExtendedMetadata struct {
-	Genre string // Comma-separated list of genres
+	Genre string
-	Label string // Record label name
+	Label string
 }
 
-// Uses the album ID from a track to fetch extended metadata
 func (c *DeezerClient) GetAlbumExtendedMetadata(ctx context.Context, albumID string) (*AlbumExtendedMetadata, error) {
 	if albumID == "" {
 		return nil, fmt.Errorf("empty album ID")
@@ -975,7 +952,6 @@ func (c *DeezerClient) GetAlbumExtendedMetadata(ctx context.Context, albumID str
 	return result, nil
 }
 
-// GetTrackAlbumID fetches the album ID for a Deezer track
 func (c *DeezerClient) GetTrackAlbumID(ctx context.Context, trackID string) (string, error) {
 	trackURL := fmt.Sprintf(deezerTrackURL, trackID)
 
@@ -987,7 +963,6 @@ func (c *DeezerClient) GetTrackAlbumID(ctx context.Context, trackID string) (str
 	return fmt.Sprintf("%d", track.Album.ID), nil
 }
 
-// This is a convenience function that first gets the album ID, then fetches album metadata
 func (c *DeezerClient) GetExtendedMetadataByTrackID(ctx context.Context, trackID string) (*AlbumExtendedMetadata, error) {
 	albumID, err := c.GetTrackAlbumID(ctx, trackID)
 	if err != nil {
@@ -997,26 +972,22 @@ func (c *DeezerClient) GetExtendedMetadataByTrackID(ctx context.Context, trackID
 	return c.GetAlbumExtendedMetadata(ctx, albumID)
 }
 
-// GetExtendedMetadataByISRC searches for a track by ISRC and fetches extended metadata (genre, label)
 func (c *DeezerClient) GetExtendedMetadataByISRC(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
 	if isrc == "" {
 		return nil, fmt.Errorf("empty ISRC")
 	}
 
-	// First, search for track by ISRC
 	track, err := c.SearchByISRC(ctx, isrc)
 	if err != nil {
 		return nil, fmt.Errorf("failed to find track by ISRC: %w", err)
 	}
 
-	// SpotifyID contains "deezer:123" format, extract the ID
 	deezerID := strings.TrimPrefix(track.SpotifyID, "deezer:")
 
 	if deezerID == "" {
 		return nil, fmt.Errorf("track found but no Deezer ID")
 	}
 
-	// Then fetch extended metadata using the Deezer track ID
 	return c.GetExtendedMetadataByTrackID(ctx, deezerID)
 }
 
@@ -1046,7 +1017,6 @@ func (c *DeezerClient) getJSON(ctx context.Context, endpoint string, dst interfa
 	return json.Unmarshal(body, dst)
 }
 
-// parseDeezerURL is internal function, returns type and ID
 func parseDeezerURL(input string) (string, string, error) {
 	trimmed := strings.TrimSpace(input)
 	if trimmed == "" {

go_backend/duplicate.go

@@ -10,7 +10,6 @@ import (
 	"time"
 )
 
-// ISRCIndex holds a cached map of ISRC -> file path for fast duplicate checking
 type ISRCIndex struct {
 	index     map[string]string // ISRC (uppercase) -> file path
 	outputDir string
@@ -25,8 +24,6 @@ var (
 	isrcIndexTTL     = 5 * time.Minute
 )
 
-// GetISRCIndex returns or builds an ISRC index for the given directory
-// Uses per-directory mutex to prevent concurrent builds (race condition fix)
 func GetISRCIndex(outputDir string) *ISRCIndex {
 	// Fast path: check cache first
 	isrcIndexCacheMu.RLock()
@@ -56,7 +53,6 @@ func GetISRCIndex(outputDir string) *ISRCIndex {
 	return buildISRCIndex(outputDir)
 }
 
-// buildISRCIndex scans a directory and builds a map of ISRC -> file path
 func buildISRCIndex(outputDir string) *ISRCIndex {
 	idx := &ISRCIndex{
 		index:     make(map[string]string),
@@ -91,7 +87,7 @@ func buildISRCIndex(outputDir string) *ISRCIndex {
 		return nil
 	})
 
-	fmt.Printf("[ISRCIndex] Built index for %s: %d files in %v\n", 
+	fmt.Printf("[ISRCIndex] Built index for %s: %d files in %v\n",
 		outputDir, fileCount, time.Since(startTime).Round(time.Millisecond))
 
 	isrcIndexCacheMu.Lock()
@@ -113,7 +109,6 @@ func (idx *ISRCIndex) lookup(isrc string) (string, bool) {
 	return path, exists
 }
 
-// remove deletes an ISRC entry from the index (internal use)
 func (idx *ISRCIndex) remove(isrc string) {
 	if isrc == "" {
 		return
@@ -125,14 +120,11 @@ func (idx *ISRCIndex) remove(isrc string) {
 	delete(idx.index, strings.ToUpper(isrc))
 }
 
-// Lookup checks if an ISRC exists in the index (gomobile compatible)
-// Returns filepath if found, empty string if not found
 func (idx *ISRCIndex) Lookup(isrc string) (string, error) {
 	path, _ := idx.lookup(isrc)
 	return path, nil
 }
 
-// Add adds a new ISRC to the index (call after successful download)
 func (idx *ISRCIndex) Add(isrc, filePath string) {
 	if isrc == "" || filePath == "" {
 		return
@@ -144,15 +136,12 @@ func (idx *ISRCIndex) Add(isrc, filePath string) {
 	idx.index[strings.ToUpper(isrc)] = filePath
 }
 
-// InvalidateCache clears the ISRC index cache for a directory
 func InvalidateISRCCache(outputDir string) {
 	isrcIndexCacheMu.Lock()
 	delete(isrcIndexCache, outputDir)
 	isrcIndexCacheMu.Unlock()
 }
 
-// checkISRCExistsInternal checks if a file with the given ISRC exists (internal use)
-// Uses ISRC index for fast lookup
 func checkISRCExistsInternal(outputDir, isrc string) (string, bool) {
 	if isrc == "" || outputDir == "" {
 		return "", false
@@ -173,13 +162,11 @@ func checkISRCExistsInternal(outputDir, isrc string) (string, bool) {
 	return filePath, true
 }
 
-// CheckISRCExists is the exported version for gomobile (returns string, error)
 func CheckISRCExists(outputDir, isrc string) (string, error) {
 	filepath, _ := checkISRCExistsInternal(outputDir, isrc)
 	return filepath, nil
 }
 
-// CheckFileExists checks if a file with the given name exists
 func CheckFileExists(filePath string) bool {
 	info, err := os.Stat(filePath)
 	if err != nil {
@@ -188,7 +175,6 @@ func CheckFileExists(filePath string) bool {
 	return !info.IsDir() && info.Size() > 0
 }
 
-// FileExistenceResult represents the result of checking if a file exists
 type FileExistenceResult struct {
 	ISRC       string `json:"isrc"`
 	Exists     bool   `json:"exists"`
@@ -249,8 +235,6 @@ func CheckFilesExistParallel(outputDir string, tracksJSON string) (string, error
 	return string(resultJSON), nil
 }
 
-// PreBuildISRCIndex pre-builds the ISRC index for a directory
-// Call this when app starts or when entering album/playlist screen
 func PreBuildISRCIndex(outputDir string) error {
 	if outputDir == "" {
 		return fmt.Errorf("output directory is required")
@@ -260,7 +244,6 @@ func PreBuildISRCIndex(outputDir string) error {
 	return nil
 }
 
-// AddToISRCIndex adds a new file to the ISRC index after successful download
 func AddToISRCIndex(outputDir, isrc, filePath string) {
 	if outputDir == "" || isrc == "" || filePath == "" {
 		return

go_backend/exports.go

@@ -148,17 +148,16 @@ type DownloadRequest struct {
 	LyricsMode           string `json:"lyrics_mode,omitempty"`
 }
 
-// DownloadResponse represents the result of a download
 type DownloadResponse struct {
 	Success                bool   `json:"success"`
 	Message                string `json:"message"`
 	FilePath               string `json:"file_path,omitempty"`
 	Error                  string `json:"error,omitempty"`
-	ErrorType              string `json:"error_type,omitempty"` // "not_found", "rate_limit", "network", "unknown"
+	ErrorType              string `json:"error_type,omitempty"`
 	AlreadyExists          bool   `json:"already_exists,omitempty"`
 	ActualBitDepth         int    `json:"actual_bit_depth,omitempty"`
 	ActualSampleRate       int    `json:"actual_sample_rate,omitempty"`
-	Service                string `json:"service,omitempty"` // Actual service used (for fallback)
+	Service                string `json:"service,omitempty"`
 	Title                  string `json:"title,omitempty"`
 	Artist                 string `json:"artist,omitempty"`
 	Album                  string `json:"album,omitempty"`
@@ -172,6 +171,7 @@ type DownloadResponse struct {
 	Label                  string `json:"label,omitempty"`
 	Copyright              string `json:"copyright,omitempty"`
 	SkipMetadataEnrichment bool   `json:"skip_metadata_enrichment,omitempty"`
+	LyricsLRC              string `json:"lyrics_lrc,omitempty"`
 }
 
 type DownloadResult struct {
@@ -185,6 +185,7 @@ type DownloadResult struct {
 	TrackNumber int
 	DiscNumber  int
 	ISRC        string
+	LyricsLRC   string
 }
 
 func DownloadTrack(requestJSON string) (string, error) {
@@ -222,6 +223,7 @@ func DownloadTrack(requestJSON string) (string, error) {
 				TrackNumber: tidalResult.TrackNumber,
 				DiscNumber:  tidalResult.DiscNumber,
 				ISRC:        tidalResult.ISRC,
+				LyricsLRC:   tidalResult.LyricsLRC,
 			}
 		}
 		err = tidalErr
@@ -317,6 +319,7 @@ func DownloadTrack(requestJSON string) (string, error) {
 		TrackNumber:      result.TrackNumber,
 		DiscNumber:       result.DiscNumber,
 		ISRC:             result.ISRC,
+		LyricsLRC:        result.LyricsLRC,
 	}
 
 	jsonBytes, _ := json.Marshal(resp)
@@ -380,6 +383,7 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 					TrackNumber: tidalResult.TrackNumber,
 					DiscNumber:  tidalResult.DiscNumber,
 					ISRC:        tidalResult.ISRC,
+					LyricsLRC:   tidalResult.LyricsLRC,
 				}
 			} else if !errors.Is(tidalErr, ErrDownloadCancelled) {
 				GoLog("[DownloadWithFallback] Tidal error: %v\n", tidalErr)
@@ -452,6 +456,7 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 					TrackNumber:      result.TrackNumber,
 					DiscNumber:       result.DiscNumber,
 					ISRC:             result.ISRC,
+					LyricsLRC:        result.LyricsLRC,
 				}
 				jsonBytes, _ := json.Marshal(resp)
 				return string(jsonBytes), nil
@@ -480,6 +485,7 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 				TrackNumber:      result.TrackNumber,
 				DiscNumber:       result.DiscNumber,
 				ISRC:             result.ISRC,
+				LyricsLRC:        result.LyricsLRC,
 			}
 			jsonBytes, _ := json.Marshal(resp)
 			return string(jsonBytes), nil
@@ -631,14 +637,11 @@ func FetchLyrics(spotifyID, trackName, artistName string, durationMs int64) (str
 }
 
 func GetLyricsLRC(spotifyID, trackName, artistName string, filePath string, durationMs int64) (string, error) {
-	// If filePath is provided, ONLY check file - don't fallback to online
-	// This allows Flutter to distinguish between "from file" vs "from online"
 	if filePath != "" {
 		lyrics, err := ExtractLyrics(filePath)
 		if err == nil && lyrics != "" {
 			return lyrics, nil
 		}
-		// File has no lyrics - return empty, let Flutter call again without filePath
 		return "", nil
 	}
 
@@ -649,7 +652,6 @@ func GetLyricsLRC(spotifyID, trackName, artistName string, filePath string, dura
 		return "", err
 	}
 
-	// Return special marker for instrumental tracks
 	if lyricsData.Instrumental {
 		return "[instrumental:true]", nil
 	}
@@ -735,8 +737,6 @@ func SearchDeezerAll(query string, trackLimit, artistLimit int, filter string) (
 }
 
 // GetDeezerMetadata fetches metadata from Deezer URL or ID
-// resourceType: track, album, artist, playlist
-// resourceID: Deezer ID
 func GetDeezerMetadata(resourceType, resourceID string) (string, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
@@ -770,7 +770,6 @@ func GetDeezerMetadata(resourceType, resourceID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// ParseDeezerURLExport parses a Deezer URL and returns type and ID
 func ParseDeezerURLExport(url string) (string, error) {
 	resourceType, resourceID, err := parseDeezerURL(url)
 	if err != nil {
@@ -790,9 +789,6 @@ func ParseDeezerURLExport(url string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetDeezerExtendedMetadata fetches genre and label from Deezer album
-// trackID: Deezer track ID (will look up album ID from track)
-// Returns JSON with genre, label fields
 func GetDeezerExtendedMetadata(trackID string) (string, error) {
 	if trackID == "" {
 		return "", fmt.Errorf("empty track ID")
@@ -821,7 +817,6 @@ func GetDeezerExtendedMetadata(trackID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SearchDeezerByISRC searches for a track by ISRC on Deezer
 func SearchDeezerByISRC(isrc string) (string, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
@@ -949,9 +944,6 @@ func CheckAvailabilityFromDeezerID(deezerTrackID string) (string, error) {
 }
 
 // CheckAvailabilityByPlatformID checks track availability using any platform as source
-// platform: "spotify", "deezer", "tidal", "amazonMusic", "appleMusic", "youtube"
-// entityType: "song" or "album"
-// entityID: the ID on that platform
 func CheckAvailabilityByPlatformID(platform, entityType, entityID string) (string, error) {
 	client := NewSongLinkClient()
 	availability, err := client.CheckAvailabilityByPlatform(platform, entityType, entityID)
@@ -967,19 +959,16 @@ func CheckAvailabilityByPlatformID(platform, entityType, entityID string) (strin
 	return string(jsonBytes), nil
 }
 
-// GetSpotifyIDFromDeezerTrack converts a Deezer track ID to Spotify track ID
 func GetSpotifyIDFromDeezerTrack(deezerTrackID string) (string, error) {
 	client := NewSongLinkClient()
 	return client.GetSpotifyIDFromDeezer(deezerTrackID)
 }
 
-// GetTidalURLFromDeezerTrack converts a Deezer track ID to Tidal URL
 func GetTidalURLFromDeezerTrack(deezerTrackID string) (string, error) {
 	client := NewSongLinkClient()
 	return client.GetTidalURLFromDeezer(deezerTrackID)
 }
 
-// GetAmazonURLFromDeezerTrack converts a Deezer track ID to Amazon Music URL
 func GetAmazonURLFromDeezerTrack(deezerTrackID string) (string, error) {
 	client := NewSongLinkClient()
 	return client.GetAmazonURLFromDeezer(deezerTrackID)
@@ -1029,7 +1018,6 @@ func errorResponse(msg string) (string, error) {
 
 // ==================== EXTENSION SYSTEM ====================
 
-// InitExtensionSystem initializes the extension system with directories
 func InitExtensionSystem(extensionsDir, dataDir string) error {
 	manager := GetExtensionManager()
 	if err := manager.SetDirectories(extensionsDir, dataDir); err != nil {
@@ -1044,7 +1032,6 @@ func InitExtensionSystem(extensionsDir, dataDir string) error {
 	return nil
 }
 
-// LoadExtensionsFromDir loads all extensions from a directory
 func LoadExtensionsFromDir(dirPath string) (string, error) {
 	manager := GetExtensionManager()
 	loaded, errors := manager.LoadExtensionsFromDirectory(dirPath)
@@ -1066,7 +1053,6 @@ func LoadExtensionsFromDir(dirPath string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// LoadExtensionFromPath loads a single extension from a .spotiflac-ext file
 func LoadExtensionFromPath(filePath string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.LoadExtensionFromFile(filePath)
@@ -1096,19 +1082,16 @@ func LoadExtensionFromPath(filePath string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// UnloadExtensionByID unloads an extension
 func UnloadExtensionByID(extensionID string) error {
 	manager := GetExtensionManager()
 	return manager.UnloadExtension(extensionID)
 }
 
-// RemoveExtensionByID completely removes an extension (unload + delete files)
 func RemoveExtensionByID(extensionID string) error {
 	manager := GetExtensionManager()
 	return manager.RemoveExtension(extensionID)
 }
 
-// UpgradeExtensionFromPath upgrades an existing extension from a new package file
 func UpgradeExtensionFromPath(filePath string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.UpgradeExtension(filePath)
@@ -1137,25 +1120,21 @@ func UpgradeExtensionFromPath(filePath string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// CheckExtensionUpgradeFromPath checks if a package file is an upgrade for an existing extension
 func CheckExtensionUpgradeFromPath(filePath string) (string, error) {
 	manager := GetExtensionManager()
 	return manager.CheckExtensionUpgradeJSON(filePath)
 }
 
-// GetInstalledExtensions returns all installed extensions as JSON
 func GetInstalledExtensions() (string, error) {
 	manager := GetExtensionManager()
 	return manager.GetInstalledExtensionsJSON()
 }
 
-// SetExtensionEnabledByID enables or disables an extension
 func SetExtensionEnabledByID(extensionID string, enabled bool) error {
 	manager := GetExtensionManager()
 	return manager.SetExtensionEnabled(extensionID, enabled)
 }
 
-// SetProviderPriorityJSON sets the provider priority order from JSON array
 func SetProviderPriorityJSON(priorityJSON string) error {
 	var priority []string
 	if err := json.Unmarshal([]byte(priorityJSON), &priority); err != nil {
@@ -1166,7 +1145,6 @@ func SetProviderPriorityJSON(priorityJSON string) error {
 	return nil
 }
 
-// GetProviderPriorityJSON returns the provider priority order as JSON
 func GetProviderPriorityJSON() (string, error) {
 	priority := GetProviderPriority()
 	jsonBytes, err := json.Marshal(priority)
@@ -1176,7 +1154,6 @@ func GetProviderPriorityJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SetMetadataProviderPriorityJSON sets the metadata provider priority order from JSON array
 func SetMetadataProviderPriorityJSON(priorityJSON string) error {
 	var priority []string
 	if err := json.Unmarshal([]byte(priorityJSON), &priority); err != nil {
@@ -1187,7 +1164,6 @@ func SetMetadataProviderPriorityJSON(priorityJSON string) error {
 	return nil
 }
 
-// GetMetadataProviderPriorityJSON returns the metadata provider priority order as JSON
 func GetMetadataProviderPriorityJSON() (string, error) {
 	priority := GetMetadataProviderPriority()
 	jsonBytes, err := json.Marshal(priority)
@@ -1197,7 +1173,6 @@ func GetMetadataProviderPriorityJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetExtensionSettingsJSON returns settings for an extension as JSON
 func GetExtensionSettingsJSON(extensionID string) (string, error) {
 	store := GetExtensionSettingsStore()
 	settings := store.GetAll(extensionID)
@@ -1210,7 +1185,6 @@ func GetExtensionSettingsJSON(extensionID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SetExtensionSettingsJSON sets settings for an extension from JSON
 func SetExtensionSettingsJSON(extensionID, settingsJSON string) error {
 	var settings map[string]interface{}
 	if err := json.Unmarshal([]byte(settingsJSON), &settings); err != nil {
@@ -1226,7 +1200,6 @@ func SetExtensionSettingsJSON(extensionID, settingsJSON string) error {
 	return manager.InitializeExtension(extensionID, settings)
 }
 
-// SearchTracksWithExtensionsJSON searches all extension metadata providers
 func SearchTracksWithExtensionsJSON(query string, limit int) (string, error) {
 	manager := GetExtensionManager()
 	tracks, err := manager.SearchTracksWithExtensions(query, limit)
@@ -1242,7 +1215,6 @@ func SearchTracksWithExtensionsJSON(query string, limit int) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// DownloadWithExtensionsJSON downloads using extension providers with fallback
 func DownloadWithExtensionsJSON(requestJSON string) (string, error) {
 	var req DownloadRequest
 	if err := json.Unmarshal([]byte(requestJSON), &req); err != nil {
@@ -1262,14 +1234,11 @@ func DownloadWithExtensionsJSON(requestJSON string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// CleanupExtensions unloads all extensions gracefully
 func CleanupExtensions() {
 	manager := GetExtensionManager()
 	manager.UnloadAllExtensions()
 }
 
-// InvokeExtensionActionJSON invokes a custom action on an extension (e.g., button click handler)
-// actionName is the JS function name to call (e.g., "startLogin", "authenticate", etc.)
 func InvokeExtensionActionJSON(extensionID, actionName string) (string, error) {
 	manager := GetExtensionManager()
 	result, err := manager.InvokeAction(extensionID, actionName)
@@ -1285,7 +1254,6 @@ func InvokeExtensionActionJSON(extensionID, actionName string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetExtensionPendingAuthJSON returns pending auth request for an extension
 func GetExtensionPendingAuthJSON(extensionID string) (string, error) {
 	req := GetPendingAuthRequest(extensionID)
 	if req == nil {
@@ -1306,12 +1274,10 @@ func GetExtensionPendingAuthJSON(extensionID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SetExtensionAuthCodeByID sets auth code for an extension (called from Flutter after OAuth callback)
 func SetExtensionAuthCodeByID(extensionID, authCode string) {
 	SetExtensionAuthCode(extensionID, authCode)
 }
 
-// SetExtensionTokensByID sets tokens for an extension
 func SetExtensionTokensByID(extensionID, accessToken, refreshToken string, expiresIn int) {
 	var expiresAt time.Time
 	if expiresIn > 0 {
@@ -1320,12 +1286,10 @@ func SetExtensionTokensByID(extensionID, accessToken, refreshToken string, expir
 	SetExtensionTokens(extensionID, accessToken, refreshToken, expiresAt)
 }
 
-// ClearExtensionPendingAuthByID clears pending auth request for an extension
 func ClearExtensionPendingAuthByID(extensionID string) {
 	ClearPendingAuthRequest(extensionID)
 }
 
-// IsExtensionAuthenticatedByID checks if an extension is authenticated
 func IsExtensionAuthenticatedByID(extensionID string) bool {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
@@ -1342,7 +1306,6 @@ func IsExtensionAuthenticatedByID(extensionID string) bool {
 	return state.IsAuthenticated
 }
 
-// GetAllPendingAuthRequestsJSON returns all pending auth requests
 func GetAllPendingAuthRequestsJSON() (string, error) {
 	pendingAuthRequestsMu.RLock()
 	defer pendingAuthRequestsMu.RUnlock()
@@ -1386,12 +1349,10 @@ func GetPendingFFmpegCommandJSON(commandID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SetFFmpegCommandResultByID sets the result of an FFmpeg command
 func SetFFmpegCommandResultByID(commandID string, success bool, output, errorMsg string) {
 	SetFFmpegCommandResult(commandID, success, output, errorMsg)
 }
 
-// GetAllPendingFFmpegCommandsJSON returns all pending FFmpeg commands
 func GetAllPendingFFmpegCommandsJSON() (string, error) {
 	ffmpegCommandsMu.RLock()
 	defer ffmpegCommandsMu.RUnlock()
@@ -1417,8 +1378,6 @@ func GetAllPendingFFmpegCommandsJSON() (string, error) {
 
 // ==================== EXTENSION CUSTOM SEARCH ====================
 
-// EnrichTrackWithExtensionJSON enriches track metadata using the source extension
-// This is called lazily before download starts, allowing extension to fetch real ISRC etc.
 func EnrichTrackWithExtensionJSON(extensionID, trackJSON string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
@@ -1449,7 +1408,6 @@ func EnrichTrackWithExtensionJSON(extensionID, trackJSON string) (string, error)
 	return string(jsonBytes), nil
 }
 
-// CustomSearchWithExtensionJSON performs custom search using an extension
 func CustomSearchWithExtensionJSON(extensionID, query string, optionsJSON string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
@@ -1502,7 +1460,6 @@ func CustomSearchWithExtensionJSON(extensionID, query string, optionsJSON string
 	return string(jsonBytes), nil
 }
 
-// GetSearchProvidersJSON returns all extensions that provide custom search
 func GetSearchProvidersJSON() (string, error) {
 	manager := GetExtensionManager()
 	providers := manager.GetSearchProviders()
@@ -1666,8 +1623,6 @@ func HandleURLWithExtensionJSON(url string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// FindURLHandlerJSON finds an extension that can handle the given URL
-// Returns extension ID or empty string if none found
 func FindURLHandlerJSON(url string) string {
 	manager := GetExtensionManager()
 	handler := manager.FindURLHandler(url)
@@ -1677,7 +1632,6 @@ func FindURLHandlerJSON(url string) string {
 	return handler.extension.ID
 }
 
-// GetAlbumWithExtensionJSON gets album tracks using an extension
 func GetAlbumWithExtensionJSON(extensionID, albumID string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
@@ -1752,7 +1706,6 @@ func GetAlbumWithExtensionJSON(extensionID, albumID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetPlaylistWithExtensionJSON gets playlist tracks using an extension
 func GetPlaylistWithExtensionJSON(extensionID, playlistID string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
@@ -1844,7 +1797,6 @@ func GetPlaylistWithExtensionJSON(extensionID, playlistID string) (string, error
 	return string(jsonBytes), nil
 }
 
-// GetArtistWithExtensionJSON gets artist info and albums using an extension
 func GetArtistWithExtensionJSON(extensionID, artistID string) (string, error) {
 	manager := GetExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
@@ -1928,7 +1880,6 @@ func GetArtistWithExtensionJSON(extensionID, artistID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetURLHandlersJSON returns all extensions that handle custom URLs
 func GetURLHandlersJSON() (string, error) {
 	manager := GetExtensionManager()
 	handlers := manager.GetURLHandlers()
@@ -1972,7 +1923,6 @@ func RunPostProcessingJSON(filePath, metadataJSON string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetPostProcessingProvidersJSON returns all extensions that provide post-processing
 func GetPostProcessingProvidersJSON() (string, error) {
 	manager := GetExtensionManager()
 	providers := manager.GetPostProcessingProviders()
@@ -2005,13 +1955,11 @@ func GetPostProcessingProvidersJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// InitExtensionStoreJSON initializes the extension store with cache directory
 func InitExtensionStoreJSON(cacheDir string) error {
 	InitExtensionStore(cacheDir)
 	return nil
 }
 
-// GetStoreExtensionsJSON returns all extensions from the store with installation status
 func GetStoreExtensionsJSON(forceRefresh bool) (string, error) {
 	store := GetExtensionStore()
 	if store == nil {
@@ -2035,7 +1983,6 @@ func GetStoreExtensionsJSON(forceRefresh bool) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// SearchStoreExtensionsJSON searches extensions in the store
 func SearchStoreExtensionsJSON(query, category string) (string, error) {
 	store := GetExtensionStore()
 	if store == nil {
@@ -2055,7 +2002,6 @@ func SearchStoreExtensionsJSON(query, category string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetStoreCategoriesJSON returns all available categories
 func GetStoreCategoriesJSON() (string, error) {
 	store := GetExtensionStore()
 	if store == nil {
@@ -2071,8 +2017,6 @@ func GetStoreCategoriesJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// DownloadStoreExtensionJSON downloads an extension from the store
-// Returns the path to the downloaded file
 func DownloadStoreExtensionJSON(extensionID, destDir string) (string, error) {
 	store := GetExtensionStore()
 	if store == nil {
@@ -2088,7 +2032,6 @@ func DownloadStoreExtensionJSON(extensionID, destDir string) (string, error) {
 	return destPath, nil
 }
 
-// ClearStoreCacheJSON clears the store cache
 func ClearStoreCacheJSON() error {
 	store := GetExtensionStore()
 	if store == nil {
@@ -2139,12 +2082,10 @@ func callExtensionFunctionJSON(extensionID, functionName string, timeout time.Du
 	return string(jsonBytes), nil
 }
 
-// GetExtensionHomeFeedJSON calls getHomeFeed on any extension that supports it
 func GetExtensionHomeFeedJSON(extensionID string) (string, error) {
 	return callExtensionFunctionJSON(extensionID, "getHomeFeed", 60*time.Second)
 }
 
-// GetExtensionBrowseCategoriesJSON calls getBrowseCategories on any extension that supports it
 func GetExtensionBrowseCategoriesJSON(extensionID string) (string, error) {
 	return callExtensionFunctionJSON(extensionID, "getBrowseCategories", 30*time.Second)
 }

go_backend/extension_manager.go

@@ -55,7 +55,6 @@ type LoadedExtension struct {
 	IconPath  string             `json:"icon_path"`
 }
 
-// ExtensionManager manages all loaded extensions
 type ExtensionManager struct {
 	mu            sync.RWMutex
 	extensions    map[string]*LoadedExtension
@@ -283,7 +282,6 @@ func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
 	return nil
 }
 
-// UnloadExtension unloads an extension by ID
 func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -311,7 +309,6 @@ func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	return nil
 }
 
-// Returns error if extension not found (gomobile compatible)
 func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, error) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -323,7 +320,6 @@ func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, e
 	return ext, nil
 }
 
-// GetAllExtensions returns all loaded extensions
 func (m *ExtensionManager) GetAllExtensions() []*LoadedExtension {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -356,7 +352,6 @@ func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool)
 	return nil
 }
 
-// LoadExtensionsFromDirectory scans a directory and loads all valid extensions
 func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
 	var loaded []string
 	var errors []error
@@ -456,7 +451,6 @@ func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedEx
 	return ext, nil
 }
 
-// RemoveExtension completely removes an extension (unload + delete files)
 func (m *ExtensionManager) RemoveExtension(extensionID string) error {
 	ext, err := m.GetExtension(extensionID)
 	if err != nil {
@@ -637,8 +631,6 @@ type ExtensionUpgradeInfo struct {
 	IsInstalled    bool   `json:"is_installed"`
 }
 
-// checkExtensionUpgradeInternal checks if a package file is an upgrade for an existing extension
-// Internal function that returns struct
 func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
 	// Validate file extension
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
@@ -714,7 +706,6 @@ func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, e
 	return string(jsonBytes), nil
 }
 
-// GetInstalledExtensionsJSON returns all extensions as JSON for Flutter
 func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	extensions := m.GetAllExtensions()
 
@@ -809,8 +800,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// ==================== Extension Lifecycle ====================
-
 func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -923,7 +912,6 @@ func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	return nil
 }
 
-// UnloadAllExtensions unloads all extensions gracefully
 func (m *ExtensionManager) UnloadAllExtensions() {
 	m.mu.Lock()
 	extensionIDs := make([]string, 0, len(m.extensions))
@@ -940,7 +928,6 @@ func (m *ExtensionManager) UnloadAllExtensions() {
 	GoLog("[Extension] All extensions unloaded\n")
 }
 
-// The function is called as extension.<actionName>() and can return a result
 func (m *ExtensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()

go_backend/extension_manifest.go

@@ -7,7 +7,6 @@ import (
 	"strings"
 )
 
-// ExtensionType represents the type of extension
 type ExtensionType string
 
 const (
@@ -15,7 +14,6 @@ const (
 	ExtensionTypeDownloadProvider ExtensionType = "download_provider"
 )
 
-// SettingType represents the type of a setting field
 type SettingType string
 
 const (
@@ -26,14 +24,12 @@ const (
 	SettingTypeButton SettingType = "button" // Action button that calls a JS function
 )
 
-// ExtensionPermissions defines what resources an extension can access
 type ExtensionPermissions struct {
-	Network []string `json:"network"` // List of allowed domains
+	Network []string `json:"network"`
-	Storage bool     `json:"storage"` // Whether extension can use storage API
+	Storage bool     `json:"storage"`
-	File    bool     `json:"file"`    // Whether extension can use file API
+	File    bool     `json:"file"`
 }
 
-// ExtensionSetting defines a configurable setting for an extension
 type ExtensionSetting struct {
 	Key         string      `json:"key"`
 	Type        SettingType `json:"type"`
@@ -42,19 +38,17 @@ type ExtensionSetting struct {
 	Required    bool        `json:"required,omitempty"`
 	Secret      bool        `json:"secret,omitempty"`
 	Default     interface{} `json:"default,omitempty"`
-	Options     []string    `json:"options,omitempty"` // For select type
+	Options     []string    `json:"options,omitempty"`
-	Action      string      `json:"action,omitempty"`  // For button type: JS function name to call (e.g., "startLogin")
+	Action      string      `json:"action,omitempty"`
 }
 
-// QualityOption represents a quality option for download providers
 type QualityOption struct {
-	ID          string                   `json:"id"`                 // Unique identifier (e.g., "mp3_320", "opus_128")
+	ID          string                   `json:"id"`
-	Label       string                   `json:"label"`              // Display name (e.g., "MP3 320kbps")
+	Label       string                   `json:"label"`
-	Description string                   `json:"description"`        // Optional description (e.g., "Best quality MP3")
+	Description string                   `json:"description"`
-	Settings    []QualitySpecificSetting `json:"settings,omitempty"` // Quality-specific settings
+	Settings    []QualitySpecificSetting `json:"settings,omitempty"`
 }
 
-// QualitySpecificSetting represents a setting that's specific to a quality option
 type QualitySpecificSetting struct {
 	Key         string      `json:"key"`
 	Type        SettingType `json:"type"`
@@ -63,57 +57,50 @@ type QualitySpecificSetting struct {
 	Required    bool        `json:"required,omitempty"`
 	Secret      bool        `json:"secret,omitempty"`
 	Default     interface{} `json:"default,omitempty"`
-	Options     []string    `json:"options,omitempty"` // For select type
+	Options     []string    `json:"options,omitempty"`
 }
 
-// SearchFilter defines a filter option for search
 type SearchFilter struct {
-	ID    string `json:"id"`              // Filter identifier (e.g., "track", "album", "artist", "playlist")
+	ID    string `json:"id"`
-	Label string `json:"label,omitempty"` // Display label (e.g., "Songs", "Albums", "Artists", "Playlists")
+	Label string `json:"label,omitempty"`
-	Icon  string `json:"icon,omitempty"`  // Optional icon name
+	Icon  string `json:"icon,omitempty"`
 }
 
-// SearchBehaviorConfig defines custom search behavior for an extension
 type SearchBehaviorConfig struct {
-	Enabled         bool           `json:"enabled"`                   // Whether extension provides custom search
+	Enabled         bool           `json:"enabled"`
-	Placeholder     string         `json:"placeholder,omitempty"`     // Placeholder text for search box
+	Placeholder     string         `json:"placeholder,omitempty"`
-	Primary         bool           `json:"primary,omitempty"`         // If true, show as primary search tab
+	Primary         bool           `json:"primary,omitempty"`
-	Icon            string         `json:"icon,omitempty"`            // Icon for search tab
+	Icon            string         `json:"icon,omitempty"`
-	ThumbnailRatio  string         `json:"thumbnailRatio,omitempty"`  // Thumbnail aspect ratio: "square" (1:1), "wide" (16:9), "portrait" (2:3)
+	ThumbnailRatio  string         `json:"thumbnailRatio,omitempty"`
-	ThumbnailWidth  int            `json:"thumbnailWidth,omitempty"`  // Custom thumbnail width in pixels
+	ThumbnailWidth  int            `json:"thumbnailWidth,omitempty"`
-	ThumbnailHeight int            `json:"thumbnailHeight,omitempty"` // Custom thumbnail height in pixels
+	ThumbnailHeight int            `json:"thumbnailHeight,omitempty"`
-	Filters         []SearchFilter `json:"filters,omitempty"`         // Available search filters (e.g., track, album, artist, playlist)
+	Filters         []SearchFilter `json:"filters,omitempty"`
 }
 
-// URLHandlerConfig defines custom URL handling for an extension
 type URLHandlerConfig struct {
-	Enabled  bool     `json:"enabled"`            // Whether extension handles URLs
+	Enabled  bool     `json:"enabled"`
-	Patterns []string `json:"patterns,omitempty"` // URL patterns to match (e.g., "music.youtube.com", "soundcloud.com")
+	Patterns []string `json:"patterns,omitempty"`
 }
 
-// TrackMatchingConfig defines custom track matching behavior
 type TrackMatchingConfig struct {
-	CustomMatching    bool   `json:"customMatching"`              // Whether extension handles matching
+	CustomMatching    bool   `json:"customMatching"`
-	Strategy          string `json:"strategy,omitempty"`          // "isrc", "name", "duration", "custom"
+	Strategy          string `json:"strategy,omitempty"`
-	DurationTolerance int    `json:"durationTolerance,omitempty"` // Tolerance in seconds for duration matching
+	DurationTolerance int    `json:"durationTolerance,omitempty"`
 }
 
-// PostProcessingHook defines a post-processing hook
 type PostProcessingHook struct {
-	ID               string   `json:"id"`                         // Unique identifier
+	ID               string   `json:"id"`
-	Name             string   `json:"name"`                       // Display name
+	Name             string   `json:"name"`
-	Description      string   `json:"description,omitempty"`      // Description
+	Description      string   `json:"description,omitempty"`
-	DefaultEnabled   bool     `json:"defaultEnabled,omitempty"`   // Whether enabled by default
+	DefaultEnabled   bool     `json:"defaultEnabled,omitempty"`
-	SupportedFormats []string `json:"supportedFormats,omitempty"` // Supported file formats (e.g., ["flac", "mp3"])
+	SupportedFormats []string `json:"supportedFormats,omitempty"`
 }
 
-// PostProcessingConfig defines post-processing capabilities
 type PostProcessingConfig struct {
-	Enabled bool                 `json:"enabled"`         // Whether extension provides post-processing
+	Enabled bool                 `json:"enabled"`
-	Hooks   []PostProcessingHook `json:"hooks,omitempty"` // Available hooks
+	Hooks   []PostProcessingHook `json:"hooks,omitempty"`
 }
 
-// ExtensionManifest represents the manifest.json of an extension
 type ExtensionManifest struct {
 	Name                   string                 `json:"name"`
 	DisplayName            string                 `json:"displayName"`
@@ -121,22 +108,21 @@ type ExtensionManifest struct {
 	Author                 string                 `json:"author"`
 	Description            string                 `json:"description"`
 	Homepage               string                 `json:"homepage,omitempty"`
-	Icon                   string                 `json:"icon,omitempty"` // Icon filename (e.g., "icon.png")
+	Icon                   string                 `json:"icon,omitempty"`
 	Types                  []ExtensionType        `json:"type"`
 	Permissions            ExtensionPermissions   `json:"permissions"`
 	Settings               []ExtensionSetting     `json:"settings,omitempty"`
-	QualityOptions         []QualityOption        `json:"qualityOptions,omitempty"` // Custom quality options for download providers
+	QualityOptions         []QualityOption        `json:"qualityOptions,omitempty"`
 	MinAppVersion          string                 `json:"minAppVersion,omitempty"`
-	SkipMetadataEnrichment bool                   `json:"skipMetadataEnrichment,omitempty"` // If true, don't enrich metadata from Deezer/Spotify
+	SkipMetadataEnrichment bool                   `json:"skipMetadataEnrichment,omitempty"`
-	SkipBuiltInFallback    bool                   `json:"skipBuiltInFallback,omitempty"`    // If true, don't fallback to built-in providers (tidal/qobuz/amazon)
+	SkipBuiltInFallback    bool                   `json:"skipBuiltInFallback,omitempty"`
-	SearchBehavior         *SearchBehaviorConfig  `json:"searchBehavior,omitempty"`         // Custom search behavior
+	SearchBehavior         *SearchBehaviorConfig  `json:"searchBehavior,omitempty"`
-	URLHandler             *URLHandlerConfig      `json:"urlHandler,omitempty"`             // Custom URL handling
+	URLHandler             *URLHandlerConfig      `json:"urlHandler,omitempty"`
-	TrackMatching          *TrackMatchingConfig   `json:"trackMatching,omitempty"`          // Custom track matching
+	TrackMatching          *TrackMatchingConfig   `json:"trackMatching,omitempty"`
-	PostProcessing         *PostProcessingConfig  `json:"postProcessing,omitempty"`         // Post-processing hooks
+	PostProcessing         *PostProcessingConfig  `json:"postProcessing,omitempty"`
-	Capabilities           map[string]interface{} `json:"capabilities,omitempty"`           // Extension capabilities (homeFeed, browseCategories, etc.)
+	Capabilities           map[string]interface{} `json:"capabilities,omitempty"`
 }
 
-// ManifestValidationError represents a validation error in the manifest
 type ManifestValidationError struct {
 	Field   string
 	Message string
@@ -146,7 +132,6 @@ func (e *ManifestValidationError) Error() string {
 	return fmt.Sprintf("manifest validation error: %s - %s", e.Field, e.Message)
 }
 
-// ParseManifest parses and validates a manifest from JSON bytes
 func ParseManifest(data []byte) (*ExtensionManifest, error) {
 	var manifest ExtensionManifest
 	if err := json.Unmarshal(data, &manifest); err != nil {
@@ -225,7 +210,6 @@ func (m *ExtensionManifest) Validate() error {
 	return nil
 }
 
-// HasType checks if the extension has a specific type
 func (m *ExtensionManifest) HasType(t ExtensionType) bool {
 	for _, et := range m.Types {
 		if et == t {
@@ -235,17 +219,14 @@ func (m *ExtensionManifest) HasType(t ExtensionType) bool {
 	return false
 }
 
-// IsMetadataProvider returns true if extension provides metadata
 func (m *ExtensionManifest) IsMetadataProvider() bool {
 	return m.HasType(ExtensionTypeMetadataProvider)
 }
 
-// IsDownloadProvider returns true if extension provides downloads
 func (m *ExtensionManifest) IsDownloadProvider() bool {
 	return m.HasType(ExtensionTypeDownloadProvider)
 }
 
-// IsDomainAllowed checks if a domain is in the allowed network permissions
 func (m *ExtensionManifest) IsDomainAllowed(domain string) bool {
 	domain = strings.ToLower(strings.TrimSpace(domain))
 	for _, allowed := range m.Permissions.Network {
@@ -264,27 +245,22 @@ func (m *ExtensionManifest) IsDomainAllowed(domain string) bool {
 	return false
 }
 
-// HasCustomSearch returns true if extension provides custom search
 func (m *ExtensionManifest) HasCustomSearch() bool {
 	return m.SearchBehavior != nil && m.SearchBehavior.Enabled
 }
 
-// HasCustomMatching returns true if extension provides custom track matching
 func (m *ExtensionManifest) HasCustomMatching() bool {
 	return m.TrackMatching != nil && m.TrackMatching.CustomMatching
 }
 
-// HasPostProcessing returns true if extension provides post-processing
 func (m *ExtensionManifest) HasPostProcessing() bool {
 	return m.PostProcessing != nil && m.PostProcessing.Enabled
 }
 
-// HasURLHandler returns true if extension handles custom URLs
 func (m *ExtensionManifest) HasURLHandler() bool {
 	return m.URLHandler != nil && m.URLHandler.Enabled && len(m.URLHandler.Patterns) > 0
 }
 
-// MatchesURL checks if a URL matches any of the extension's URL patterns
 func (m *ExtensionManifest) MatchesURL(urlStr string) bool {
 	if !m.HasURLHandler() {
 		return false
@@ -301,7 +277,6 @@ func (m *ExtensionManifest) MatchesURL(urlStr string) bool {
 	return false
 }
 
-// GetPostProcessingHooks returns all post-processing hooks
 func (m *ExtensionManifest) GetPostProcessingHooks() []PostProcessingHook {
 	if m.PostProcessing == nil {
 		return nil
@@ -309,7 +284,6 @@ func (m *ExtensionManifest) GetPostProcessingHooks() []PostProcessingHook {
 	return m.PostProcessing.Hooks
 }
 
-// ToJSON serializes the manifest to JSON
 func (m *ExtensionManifest) ToJSON() ([]byte, error) {
 	return json.Marshal(m)
 }

go_backend/extension_providers.go

@@ -732,7 +732,7 @@ func GetMetadataProviderPriority() []string {
 // isBuiltInProvider checks if a provider ID is a built-in provider
 func isBuiltInProvider(providerID string) bool {
 	switch providerID {
-	case "tidal", "qobuz", "amazon":
+	case "tidal", "qobuz", "amazon", "deezer":
 		return true
 	default:
 		return false
@@ -748,6 +748,21 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 	priority := GetProviderPriority()
 	extManager := GetExtensionManager()
 
+	// If req.Service is a built-in provider, prioritize it first
+	// This handles user's explicit selection from the service picker
+	if req.Service != "" && isBuiltInProvider(req.Service) {
+		GoLog("[DownloadWithExtensionFallback] User selected service: %s, prioritizing it first\n", req.Service)
+		// Reorder priority to put req.Service first
+		newPriority := []string{req.Service}
+		for _, p := range priority {
+			if p != req.Service {
+				newPriority = append(newPriority, p)
+			}
+		}
+		priority = newPriority
+		GoLog("[DownloadWithExtensionFallback] New priority order: %v\n", priority)
+	}
+
 	var lastErr error
 	var skipBuiltIn bool // If source extension has skipBuiltInFallback, don't try built-in providers
 

go_backend/extension_runtime.go

@@ -23,9 +23,8 @@ type ExtensionAuthState struct {
 	RefreshToken    string
 	ExpiresAt       time.Time
 	IsAuthenticated bool
-	// PKCE support
+	PKCEVerifier    string
-	PKCEVerifier  string
+	PKCEChallenge   string
-	PKCEChallenge string
 }
 
 type PendingAuthRequest struct {
@@ -39,7 +38,6 @@ var (
 	pendingAuthRequestsMu sync.RWMutex
 )
 
-// GetPendingAuthRequest returns pending auth request for an extension (called from Flutter)
 func GetPendingAuthRequest(extensionID string) *PendingAuthRequest {
 	pendingAuthRequestsMu.RLock()
 	defer pendingAuthRequestsMu.RUnlock()
@@ -201,7 +199,6 @@ func (r *ExtensionRuntime) SetSettings(settings map[string]interface{}) {
 	r.settings = settings
 }
 
-// RegisterAPIs registers all sandboxed APIs to the Goja VM
 func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	r.vm = vm
 
@@ -212,7 +209,7 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	httpObj.Set("put", r.httpPut)
 	httpObj.Set("delete", r.httpDelete)
 	httpObj.Set("patch", r.httpPatch)
-	httpObj.Set("request", r.httpRequest) // Generic HTTP request (GET, POST, PUT, DELETE, etc.)
+	httpObj.Set("request", r.httpRequest)
 	httpObj.Set("clearCookies", r.httpClearCookies)
 	vm.Set("http", httpObj)
 
@@ -222,7 +219,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	storageObj.Set("remove", r.storageRemove)
 	vm.Set("storage", storageObj)
 
-	// Secure Credentials API (encrypted storage for sensitive data)
 	credentialsObj := vm.NewObject()
 	credentialsObj.Set("store", r.credentialsStore)
 	credentialsObj.Set("get", r.credentialsGet)
@@ -237,7 +233,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	authObj.Set("clearAuth", r.authClear)
 	authObj.Set("isAuthenticated", r.authIsAuthenticated)
 	authObj.Set("getTokens", r.authGetTokens)
-	// PKCE support
 	authObj.Set("generatePKCE", r.authGeneratePKCE)
 	authObj.Set("getPKCE", r.authGetPKCE)
 	authObj.Set("startOAuthWithPKCE", r.authStartOAuthWithPKCE)
@@ -279,14 +274,12 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	utilsObj.Set("hmacSHA1", r.hmacSHA1)
 	utilsObj.Set("parseJSON", r.parseJSON)
 	utilsObj.Set("stringifyJSON", r.stringifyJSON)
-	// Crypto utilities for developers
 	utilsObj.Set("encrypt", r.cryptoEncrypt)
 	utilsObj.Set("decrypt", r.cryptoDecrypt)
 	utilsObj.Set("generateKey", r.cryptoGenerateKey)
 	utilsObj.Set("randomUserAgent", r.randomUserAgent)
 	vm.Set("utils", utilsObj)
 
-	// Log object (already set in extension_manager.go, but we can enhance it)
 	logObj := vm.NewObject()
 	logObj.Set("debug", r.logDebug)
 	logObj.Set("info", r.logInfo)
@@ -298,10 +291,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	gobackendObj.Set("sanitizeFilename", r.sanitizeFilenameWrapper)
 	vm.Set("gobackend", gobackendObj)
 
-	// ==================== Browser-like Polyfills ====================
-	// These make porting browser/Node.js libraries easier
-
-	// Global fetch() - Promise-style HTTP API (browser-compatible)
 	vm.Set("fetch", r.fetchPolyfill)
 
 	vm.Set("atob", r.atobPolyfill)

go_backend/extension_runtime_auth.go

@@ -70,13 +70,11 @@ func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(state.AuthCode)
 }
 
-// authSetCode sets auth code and tokens (can be called by extension after token exchange)
 func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
 
-	// Can accept either just auth code or an object with tokens
 	arg := call.Arguments[0].Export()
 
 	extensionAuthStateMu.Lock()

go_backend/extension_runtime_file.go

@@ -15,7 +15,6 @@ import (
 
 // ==================== File API (Sandboxed) ====================
 
-// List of allowed directories for file operations (set by Go backend for download operations)
 var (
 	allowedDownloadDirs   []string
 	allowedDownloadDirsMu sync.RWMutex
@@ -49,9 +48,6 @@ func isPathInAllowedDirs(absPath string) bool {
 	return false
 }
 
-// validatePath checks if the path is within the extension's sandbox
-// Security: Absolute paths are BLOCKED unless they're in allowed download directories
-// Extensions should use relative paths for their own data storage
 func (r *ExtensionRuntime) validatePath(path string) (string, error) {
 	// Check if extension has file permission
 	if !r.manifest.Permissions.File {

go_backend/extension_runtime_http.go

@@ -14,14 +14,12 @@ import (
 
 // ==================== HTTP API (Sandboxed) ====================
 
-// HTTPResponse represents the response from an HTTP request
 type HTTPResponse struct {
 	StatusCode int               `json:"statusCode"`
 	Body       string            `json:"body"`
 	Headers    map[string]string `json:"headers"`
 }
 
-// validateDomain checks if the domain is allowed by the extension's permissions
 func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	parsed, err := url.Parse(urlStr)
 	if err != nil {
@@ -42,7 +40,6 @@ func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	return nil
 }
 
-// httpGet performs a GET request (sandboxed)
 func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -76,16 +73,14 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set default User-Agent if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -101,26 +96,24 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers (cookies, etc.)
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-// httpPost performs a POST request (sandboxed)
 func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -137,7 +130,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Get body if provided - support both string and object
 	var bodyStr string
 	if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 		bodyArg := call.Arguments[1].Export()
@@ -145,7 +137,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		case string:
 			bodyStr = v
 		case map[string]interface{}, []interface{}:
-			// Auto-stringify objects and arrays to JSON
 			jsonBytes, err := json.Marshal(v)
 			if err != nil {
 				return r.vm.ToValue(map[string]interface{}{
@@ -154,12 +145,10 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 			}
 			bodyStr = string(jsonBytes)
 		default:
-			// Fallback to string conversion
 			bodyStr = call.Arguments[1].String()
 		}
 	}
 
-	// Get headers if provided
 	headers := make(map[string]string)
 	if len(call.Arguments) > 2 && !goja.IsUndefined(call.Arguments[2]) && !goja.IsNull(call.Arguments[2]) {
 		headersObj := call.Arguments[2].Export()
@@ -177,11 +166,10 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set defaults if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
@@ -189,7 +177,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -205,19 +192,18 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
@@ -240,27 +226,22 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Default options
 	method := "GET"
 	var bodyStr string
 	headers := make(map[string]string)
 
-	// Parse options if provided
 	if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 		optionsObj := call.Arguments[1].Export()
 		if opts, ok := optionsObj.(map[string]interface{}); ok {
-			// Get method
 			if m, ok := opts["method"].(string); ok {
 				method = strings.ToUpper(m)
 			}
 
-			// Get body - support both string and object
 			if bodyArg, ok := opts["body"]; ok && bodyArg != nil {
 				switch v := bodyArg.(type) {
 				case string:
 					bodyStr = v
 				case map[string]interface{}, []interface{}:
-					// Auto-stringify objects and arrays to JSON
 					jsonBytes, err := json.Marshal(v)
 					if err != nil {
 						return r.vm.ToValue(map[string]interface{}{
@@ -273,7 +254,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 				}
 			}
 
-			// Get headers
 			if h, ok := opts["headers"].(map[string]interface{}); ok {
 				for k, v := range h {
 					headers[k] = fmt.Sprintf("%v", v)
@@ -282,7 +262,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		}
 	}
 
-	// Create request
 	var reqBody io.Reader
 	if bodyStr != "" {
 		reqBody = strings.NewReader(bodyStr)
@@ -295,11 +274,10 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set defaults if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
@@ -307,7 +285,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -323,20 +300,18 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
-	// Return response with helper properties
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
@@ -347,7 +322,6 @@ func (r *ExtensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PUT", call)
 }
 
-// httpDelete performs a DELETE request (shortcut for http.request with method: "DELETE")
 func (r *ExtensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("DELETE", call)
 }
@@ -356,8 +330,6 @@ func (r *ExtensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PATCH", call)
 }
 
-// httpMethodShortcut is a helper for PUT/DELETE/PATCH shortcuts
-// Signature: http.put(url, body, headers) / http.delete(url, headers) / http.patch(url, body, headers)
 func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -377,9 +349,7 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	var bodyStr string
 	headers := make(map[string]string)
 
-	// For DELETE, second arg is headers; for PUT/PATCH, second arg is body
 	if method == "DELETE" {
-		// http.delete(url, headers)
 		if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 			headersObj := call.Arguments[1].Export()
 			if h, ok := headersObj.(map[string]interface{}); ok {
@@ -389,7 +359,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 			}
 		}
 	} else {
-		// http.put(url, body, headers) / http.patch(url, body, headers)
 		if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 			bodyArg := call.Arguments[1].Export()
 			switch v := bodyArg.(type) {
@@ -418,7 +387,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		}
 	}
 
-	// Create request
 	var reqBody io.Reader
 	if bodyStr != "" {
 		reqBody = strings.NewReader(bodyStr)
@@ -431,7 +399,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
@@ -442,7 +409,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -458,7 +424,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		})
 	}
 
-	// Extract response headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {

go_backend/extension_runtime_storage.go

@@ -17,12 +17,10 @@ import (
 
 // ==================== Storage API ====================
 
-// getStoragePath returns the path to the extension's storage file
 func (r *ExtensionRuntime) getStoragePath() string {
 	return filepath.Join(r.dataDir, "storage.json")
 }
 
-// loadStorage loads the storage data from disk
 func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	storagePath := r.getStoragePath()
 	data, err := os.ReadFile(storagePath)
@@ -41,7 +39,6 @@ func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	return storage, nil
 }
 
-// saveStorage saves the storage data to disk
 func (r *ExtensionRuntime) saveStorage(storage map[string]interface{}) error {
 	storagePath := r.getStoragePath()
 	data, err := json.MarshalIndent(storage, "", "  ")
@@ -52,7 +49,6 @@ func (r *ExtensionRuntime) saveStorage(storage map[string]interface{}) error {
 	return os.WriteFile(storagePath, data, 0644)
 }
 
-// storageGet retrieves a value from storage
 func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -68,7 +64,6 @@ func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 
 	value, exists := storage[key]
 	if !exists {
-		// Return default value if provided
 		if len(call.Arguments) > 1 {
 			return call.Arguments[1]
 		}
@@ -78,7 +73,6 @@ func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-// storageSet stores a value in storage
 func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
@@ -103,7 +97,6 @@ func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-// storageRemove removes a value from storage
 func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -127,19 +120,14 @@ func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-// ==================== Credentials API (Encrypted Storage) ====================
-
-// getCredentialsPath returns the path to the extension's encrypted credentials file
 func (r *ExtensionRuntime) getCredentialsPath() string {
 	return filepath.Join(r.dataDir, ".credentials.enc")
 }
 
-// getSaltPath returns the path to the extension's encryption salt file
 func (r *ExtensionRuntime) getSaltPath() string {
 	return filepath.Join(r.dataDir, ".cred_salt")
 }
 
-// getOrCreateSalt gets existing salt or creates a new random one
 func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	saltPath := r.getSaltPath()
 
@@ -160,22 +148,17 @@ func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	return salt, nil
 }
 
-// getEncryptionKey derives an encryption key from extension ID + random salt
 func (r *ExtensionRuntime) getEncryptionKey() ([]byte, error) {
-	// Get or create per-installation random salt
 	salt, err := r.getOrCreateSalt()
 	if err != nil {
 		return nil, err
 	}
 
-	// Combine extension ID + random salt for key derivation
-	// This makes each installation unique, preventing mass decryption attacks
 	combined := append([]byte(r.extensionID), salt...)
 	hash := sha256.Sum256(combined)
 	return hash[:], nil
 }
 
-// loadCredentials loads and decrypts credentials from disk
 func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	credPath := r.getCredentialsPath()
 	data, err := os.ReadFile(credPath)
@@ -186,7 +169,6 @@ func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 		return nil, err
 	}
 
-	// Decrypt the data
 	key, err := r.getEncryptionKey()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get encryption key: %w", err)
@@ -204,7 +186,6 @@ func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	return creds, nil
 }
 
-// saveCredentials encrypts and saves credentials to disk
 func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	data, err := json.Marshal(creds)
 	if err != nil {
@@ -221,10 +202,9 @@ func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	}
 
 	credPath := r.getCredentialsPath()
-	return os.WriteFile(credPath, encrypted, 0600) // Restrictive permissions
+	return os.WriteFile(credPath, encrypted, 0600)
 }
 
-// credentialsStore stores an encrypted credential
 func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -260,7 +240,6 @@ func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// credentialsGet retrieves a decrypted credential
 func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -276,7 +255,6 @@ func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 
 	value, exists := creds[key]
 	if !exists {
-		// Return default value if provided
 		if len(call.Arguments) > 1 {
 			return call.Arguments[1]
 		}
@@ -286,7 +264,6 @@ func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-// credentialsRemove removes a credential
 func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -310,7 +287,6 @@ func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value
 	return r.vm.ToValue(true)
 }
 
-// credentialsHas checks if a credential exists
 func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -327,9 +303,6 @@ func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(exists)
 }
 
-// ==================== Crypto Utilities ====================
-
-// encryptAES encrypts data using AES-GCM
 func encryptAES(plaintext []byte, key []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {
@@ -350,7 +323,6 @@ func encryptAES(plaintext []byte, key []byte) ([]byte, error) {
 	return ciphertext, nil
 }
 
-// decryptAES decrypts data using AES-GCM
 func decryptAES(ciphertext []byte, key []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {

go_backend/extension_runtime_utils.go

@@ -19,7 +19,6 @@ import (
 
 // ==================== Utility Functions ====================
 
-// base64Encode encodes a string to base64
 func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -28,7 +27,6 @@ func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-// base64Decode decodes a base64 string
 func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -41,7 +39,6 @@ func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-// md5Hash computes MD5 hash of a string
 func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -51,7 +48,6 @@ func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-// sha256Hash computes SHA256 hash of a string
 func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -61,7 +57,6 @@ func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-// hmacSHA256 computes HMAC-SHA256 of a message with a key
 func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
@@ -74,7 +69,6 @@ func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(mac.Sum(nil)))
 }
 
-// hmacSHA256Base64 computes HMAC-SHA256 and returns base64 encoded result
 func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
@@ -87,9 +81,6 @@ func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString(mac.Sum(nil)))
 }
 
-// hmacSHA1 computes HMAC-SHA1 of a message with a key (for TOTP)
-// Arguments: message (string or array of bytes), key (string or array of bytes)
-// Returns: array of bytes (for TOTP dynamic truncation)
 func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue([]byte{})
@@ -142,7 +133,6 @@ func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(jsArray)
 }
 
-// parseJSON parses a JSON string
 func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -158,7 +148,6 @@ func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(result)
 }
 
-// stringifyJSON converts a value to JSON string
 func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -174,9 +163,6 @@ func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(data))
 }
 
-// ==================== Crypto Utilities for Extensions ====================
-
-// cryptoEncrypt encrypts a string using AES-GCM (for extension use)
 func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -188,7 +174,6 @@ func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	plaintext := call.Arguments[0].String()
 	keyStr := call.Arguments[1].String()
 
-	// Derive 32-byte key from provided key string
 	keyHash := sha256.Sum256([]byte(keyStr))
 
 	encrypted, err := encryptAES([]byte(plaintext), keyHash[:])
@@ -205,7 +190,6 @@ func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// cryptoDecrypt decrypts a string using AES-GCM (for extension use)
 func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -225,14 +209,13 @@ func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Derive 32-byte key from provided key string
 	keyHash := sha256.Sum256([]byte(keyStr))
 
 	decrypted, err := decryptAES(ciphertext, keyHash[:])
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
-			"error":   err.Error(),
+			"error":   "invalid base64 ciphertext",
 		})
 	}
 
@@ -242,9 +225,8 @@ func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// cryptoGenerateKey generates a random encryption key
 func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
-	length := 32 // Default 256-bit key
+	length := 32
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok {
 			length = int(l)
@@ -266,13 +248,10 @@ func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value
 	})
 }
 
-// randomUserAgent returns a random Chrome User-Agent string
 func (r *ExtensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(getRandomUserAgent())
 }
 
-// ==================== Logging Functions ====================
-
 func (r *ExtensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
 	GoLog("[Extension:%s:DEBUG] %s\n", r.extensionID, msg)
@@ -305,8 +284,6 @@ func (r *ExtensionRuntime) formatLogArgs(args []goja.Value) string {
 	return strings.Join(parts, " ")
 }
 
-// ==================== Go Backend Wrappers ====================
-
 func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -315,7 +292,6 @@ func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.
 	return r.vm.ToValue(sanitizeFilename(input))
 }
 
-// RegisterGoBackendAPIs adds more Go backend functions to the VM
 func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 	gobackendObj := vm.Get("gobackend")
 	if gobackendObj == nil || goja.IsUndefined(gobackendObj) {
@@ -325,7 +301,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 
 	obj := gobackendObj.(*goja.Object)
 
-	// Expose sanitizeFilename
 	obj.Set("sanitizeFilename", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 1 {
 			return vm.ToValue("")
@@ -333,7 +308,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 		return vm.ToValue(sanitizeFilename(call.Arguments[0].String()))
 	})
 
-	// Expose getAudioQuality
 	obj.Set("getAudioQuality", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 1 {
 			return vm.ToValue(map[string]interface{}{
@@ -356,7 +330,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 		})
 	})
 
-	// Expose buildFilename
 	obj.Set("buildFilename", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 2 {
 			return vm.ToValue("")
@@ -373,7 +346,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 		return vm.ToValue(buildFilenameFromTemplate(template, metadata))
 	})
 
-	// Expose getLocalTime - returns device local time info
 	obj.Set("getLocalTime", func(call goja.FunctionCall) goja.Value {
 		now := time.Now()
 		_, offsetSeconds := now.Zone()

go_backend/extension_settings.go

@@ -9,7 +9,6 @@ import (
 	"sync"
 )
 
-// ExtensionSettingsStore manages settings for all extensions
 type ExtensionSettingsStore struct {
 	mu       sync.RWMutex
 	dataDir  string
@@ -22,7 +21,6 @@ var (
 	globalSettingsStoreOnce sync.Once
 )
 
-// GetExtensionSettingsStore returns the global settings store
 func GetExtensionSettingsStore() *ExtensionSettingsStore {
 	globalSettingsStoreOnce.Do(func() {
 		globalSettingsStore = &ExtensionSettingsStore{
@@ -32,7 +30,6 @@ func GetExtensionSettingsStore() *ExtensionSettingsStore {
 	return globalSettingsStore
 }
 
-// SetDataDir sets the data directory for settings storage
 func (s *ExtensionSettingsStore) SetDataDir(dataDir string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -45,12 +42,10 @@ func (s *ExtensionSettingsStore) SetDataDir(dataDir string) error {
 	return s.loadAllSettings()
 }
 
-// getSettingsPath returns the path to an extension's settings file
 func (s *ExtensionSettingsStore) getSettingsPath(extensionID string) string {
 	return filepath.Join(s.dataDir, extensionID, "settings.json")
 }
 
-// loadAllSettings loads settings for all extensions from disk
 func (s *ExtensionSettingsStore) loadAllSettings() error {
 	entries, err := os.ReadDir(s.dataDir)
 	if err != nil {
@@ -75,7 +70,6 @@ func (s *ExtensionSettingsStore) loadAllSettings() error {
 	return nil
 }
 
-// loadSettings loads settings for a specific extension
 func (s *ExtensionSettingsStore) loadSettings(extensionID string) (map[string]interface{}, error) {
 	settingsPath := s.getSettingsPath(extensionID)
 	data, err := os.ReadFile(settingsPath)
@@ -94,7 +88,6 @@ func (s *ExtensionSettingsStore) loadSettings(extensionID string) (map[string]in
 	return settings, nil
 }
 
-// saveSettings saves settings for a specific extension
 func (s *ExtensionSettingsStore) saveSettings(extensionID string, settings map[string]interface{}) error {
 	settingsPath := s.getSettingsPath(extensionID)
 
@@ -111,8 +104,6 @@ func (s *ExtensionSettingsStore) saveSettings(extensionID string, settings map[s
 	return os.WriteFile(settingsPath, data, 0644)
 }
 
-// Get retrieves a setting value for an extension
-// Returns error if extension or key not found (gomobile compatible)
 func (s *ExtensionSettingsStore) Get(extensionID, key string) (interface{}, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -129,7 +120,6 @@ func (s *ExtensionSettingsStore) Get(extensionID, key string) (interface{}, erro
 	return value, nil
 }
 
-// GetAll retrieves all settings for an extension
 func (s *ExtensionSettingsStore) GetAll(extensionID string) map[string]interface{} {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -147,7 +137,6 @@ func (s *ExtensionSettingsStore) GetAll(extensionID string) map[string]interface
 	return result
 }
 
-// Set stores a setting value for an extension
 func (s *ExtensionSettingsStore) Set(extensionID, key string, value interface{}) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -161,7 +150,6 @@ func (s *ExtensionSettingsStore) Set(extensionID, key string, value interface{})
 	return s.saveSettings(extensionID, s.settings[extensionID])
 }
 
-// SetAll stores all settings for an extension
 func (s *ExtensionSettingsStore) SetAll(extensionID string, settings map[string]interface{}) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -172,7 +160,6 @@ func (s *ExtensionSettingsStore) SetAll(extensionID string, settings map[string]
 	return s.saveSettings(extensionID, settings)
 }
 
-// Remove removes a setting for an extension
 func (s *ExtensionSettingsStore) Remove(extensionID, key string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -188,7 +175,6 @@ func (s *ExtensionSettingsStore) Remove(extensionID, key string) error {
 	return s.saveSettings(extensionID, extSettings)
 }
 
-// RemoveAll removes all settings for an extension
 func (s *ExtensionSettingsStore) RemoveAll(extensionID string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -203,7 +189,6 @@ func (s *ExtensionSettingsStore) RemoveAll(extensionID string) error {
 	return nil
 }
 
-// GetAllExtensionSettings returns settings for all extensions as JSON
 func (s *ExtensionSettingsStore) GetAllExtensionSettingsJSON() (string, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()

go_backend/extension_store.go

@@ -20,28 +20,26 @@ const (
 	CategoryIntegration = "integration"
 )
 
-// StoreExtension represents an extension in the store
 type StoreExtension struct {
-	ID            string   `json:"id"`
+	ID               string   `json:"id"`
-	Name          string   `json:"name"`
+	Name             string   `json:"name"`
-	DisplayName   string   `json:"display_name,omitempty"`
+	DisplayName      string   `json:"display_name,omitempty"`
-	Version       string   `json:"version"`
+	Version          string   `json:"version"`
-	Author        string   `json:"author"`
+	Author           string   `json:"author"`
-	Description   string   `json:"description"`
+	Description      string   `json:"description"`
-	DownloadURL   string   `json:"download_url,omitempty"`
+	DownloadURL      string   `json:"download_url,omitempty"`
-	IconURL       string   `json:"icon_url,omitempty"`
+	IconURL          string   `json:"icon_url,omitempty"`
-	Category      string   `json:"category"`
+	Category         string   `json:"category"`
-	Tags          []string `json:"tags,omitempty"`
+	Tags             []string `json:"tags,omitempty"`
-	Downloads     int      `json:"downloads"`
+	Downloads        int      `json:"downloads"`
-	UpdatedAt     string   `json:"updated_at"`
+	UpdatedAt        string   `json:"updated_at"`
-	MinAppVersion string   `json:"min_app_version,omitempty"`
+	MinAppVersion    string   `json:"min_app_version,omitempty"`
-	DisplayNameAlt   string `json:"displayName,omitempty"`
+	DisplayNameAlt   string   `json:"displayName,omitempty"`
-	DownloadURLAlt   string `json:"downloadUrl,omitempty"`
+	DownloadURLAlt   string   `json:"downloadUrl,omitempty"`
-	IconURLAlt       string `json:"iconUrl,omitempty"`
+	IconURLAlt       string   `json:"iconUrl,omitempty"`
-	MinAppVersionAlt string `json:"minAppVersion,omitempty"`
+	MinAppVersionAlt string   `json:"minAppVersion,omitempty"`
 }
 
-// getDisplayName returns display name, falling back to name (private to avoid gomobile conflict)
 func (e *StoreExtension) getDisplayName() string {
 	if e.DisplayName != "" {
 		return e.DisplayName
@@ -52,7 +50,6 @@ func (e *StoreExtension) getDisplayName() string {
 	return e.Name
 }
 
-// getDownloadURL returns download URL from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getDownloadURL() string {
 	if e.DownloadURL != "" {
 		return e.DownloadURL
@@ -60,7 +57,6 @@ func (e *StoreExtension) getDownloadURL() string {
 	return e.DownloadURLAlt
 }
 
-// getIconURL returns icon URL from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getIconURL() string {
 	if e.IconURL != "" {
 		return e.IconURL
@@ -68,7 +64,6 @@ func (e *StoreExtension) getIconURL() string {
 	return e.IconURLAlt
 }
 
-// getMinAppVersion returns min app version from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getMinAppVersion() string {
 	if e.MinAppVersion != "" {
 		return e.MinAppVersion
@@ -76,7 +71,6 @@ func (e *StoreExtension) getMinAppVersion() string {
 	return e.MinAppVersionAlt
 }
 
-// StoreRegistry represents the extension registry
 type StoreRegistry struct {
 	Version    int              `json:"version"`
 	UpdatedAt  string           `json:"updated_at"`
@@ -103,7 +97,6 @@ type StoreExtensionResponse struct {
 	HasUpdate        bool     `json:"has_update"`
 }
 
-// ToResponse converts StoreExtension to normalized response
 func (e *StoreExtension) ToResponse() StoreExtensionResponse {
 	return StoreExtensionResponse{
 		ID:            e.ID,
@@ -122,7 +115,6 @@ func (e *StoreExtension) ToResponse() StoreExtensionResponse {
 	}
 }
 
-// ExtensionStore manages the extension store
 type ExtensionStore struct {
 	registryURL string
 	cacheDir    string
@@ -143,7 +135,6 @@ const (
 	cacheFileName      = "store_cache.json"
 )
 
-// InitExtensionStore initializes the extension store
 func InitExtensionStore(cacheDir string) *ExtensionStore {
 	extensionStoreMu.Lock()
 	defer extensionStoreMu.Unlock()
@@ -160,14 +151,12 @@ func InitExtensionStore(cacheDir string) *ExtensionStore {
 	return extensionStore
 }
 
-// GetExtensionStore returns the singleton store instance
 func GetExtensionStore() *ExtensionStore {
 	extensionStoreMu.Lock()
 	defer extensionStoreMu.Unlock()
 	return extensionStore
 }
 
-// loadDiskCache loads cached registry from disk
 func (s *ExtensionStore) loadDiskCache() {
 	if s.cacheDir == "" {
 		return
@@ -193,7 +182,6 @@ func (s *ExtensionStore) loadDiskCache() {
 	LogDebug("ExtensionStore", "Loaded %d extensions from disk cache", len(s.cache.Extensions))
 }
 
-// saveDiskCache saves registry to disk cache
 func (s *ExtensionStore) saveDiskCache() {
 	if s.cacheDir == "" || s.cache == nil {
 		return
@@ -216,7 +204,6 @@ func (s *ExtensionStore) saveDiskCache() {
 	os.WriteFile(cachePath, data, 0644)
 }
 
-// FetchRegistry fetches the extension registry from GitHub
 func (s *ExtensionStore) FetchRegistry(forceRefresh bool) (*StoreRegistry, error) {
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()
@@ -267,7 +254,6 @@ func (s *ExtensionStore) FetchRegistry(forceRefresh bool) (*StoreRegistry, error
 	return &registry, nil
 }
 
-// GetExtensionsWithStatus returns extensions with installation status
 func (s *ExtensionStore) GetExtensionsWithStatus() ([]StoreExtensionResponse, error) {
 	registry, err := s.FetchRegistry(false)
 	if err != nil {
@@ -299,7 +285,6 @@ func (s *ExtensionStore) GetExtensionsWithStatus() ([]StoreExtensionResponse, er
 	return result, nil
 }
 
-// DownloadExtension downloads an extension package to the specified path
 func (s *ExtensionStore) DownloadExtension(extensionID string, destPath string) error {
 	registry, err := s.FetchRegistry(false)
 	if err != nil {
@@ -347,7 +332,6 @@ func (s *ExtensionStore) DownloadExtension(extensionID string, destPath string)
 	return nil
 }
 
-// GetCategories returns all available categories
 func (s *ExtensionStore) GetCategories() []string {
 	return []string{
 		CategoryMetadata,
@@ -358,7 +342,6 @@ func (s *ExtensionStore) GetCategories() []string {
 	}
 }
 
-// SearchExtensions searches extensions by query
 func (s *ExtensionStore) SearchExtensions(query string, category string) ([]StoreExtensionResponse, error) {
 	extensions, err := s.GetExtensionsWithStatus()
 	if err != nil {
@@ -404,7 +387,6 @@ func (s *ExtensionStore) SearchExtensions(query string, category string) ([]Stor
 	return result, nil
 }
 
-// ClearCache clears the in-memory and disk cache
 func (s *ExtensionStore) ClearCache() {
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()

go_backend/httputil.go

@@ -15,9 +15,6 @@ import (
 	"time"
 )
 
-// getRandomUserAgent generates a random Windows Chrome User-Agent string
-// Uses modern Chrome format with build and patch numbers
-// Windows 11 still reports as "Windows NT 10.0" for compatibility
 func getRandomUserAgent() string {
 	// Chrome version 120-145 (modern range)
 	chromeVersion := rand.Intn(26) + 120
@@ -38,10 +35,9 @@ const (
 	SongLinkTimeout   = 30 * time.Second
 	DefaultMaxRetries = 3
 	DefaultRetryDelay = 1 * time.Second
-	Second            = time.Second // Exported for use in other files
+	Second            = time.Second
 )
 
-// Shared transport with connection pooling to prevent TCP exhaustion
 var sharedTransport = &http.Transport{
 	DialContext: (&net.Dialer{
 		Timeout:   30 * time.Second,
@@ -85,7 +81,6 @@ func GetDownloadClient() *http.Client {
 	return downloadClient
 }
 
-// CloseIdleConnections closes idle connections in the shared transport
 func CloseIdleConnections() {
 	sharedTransport.CloseIdleConnections()
 }
@@ -117,9 +112,6 @@ func DefaultRetryConfig() RetryConfig {
 	}
 }
 
-// DoRequestWithRetry executes an HTTP request with retry logic and exponential backoff
-// Handles 429 (Too Many Requests) responses with Retry-After header
-// Also detects and logs ISP blocking
 func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConfig) (*http.Response, error) {
 	var lastErr error
 	delay := config.InitialDelay
@@ -149,12 +141,10 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			continue
 		}
 
-		// Success
 		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
 			return resp, nil
 		}
 
-		// Handle rate limiting (429)
 		if resp.StatusCode == 429 {
 			resp.Body.Close()
 			retryAfter := getRetryAfterDuration(resp)
@@ -194,7 +184,6 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			}
 		}
 
-		// Server errors (5xx) - retry
 		if resp.StatusCode >= 500 {
 			resp.Body.Close()
 			lastErr = fmt.Errorf("server error: HTTP %d", resp.StatusCode)
@@ -206,7 +195,6 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			continue
 		}
 
-		// Client errors (4xx except 429) - don't retry
 		return resp, nil
 	}
 
@@ -225,12 +213,10 @@ func getRetryAfterDuration(resp *http.Response) time.Duration {
 		return 60 * time.Second // Default wait time
 	}
 
-	// Try parsing as seconds
 	if seconds, err := strconv.Atoi(retryAfter); err == nil {
 		return time.Duration(seconds) * time.Second
 	}
 
-	// Try parsing as HTTP date
 	if t, err := http.ParseTime(retryAfter); err == nil {
 		duration := time.Until(t)
 		if duration > 0 {
@@ -241,8 +227,6 @@ func getRetryAfterDuration(resp *http.Response) time.Duration {
 	return 60 * time.Second // Default
 }
 
-// ReadResponseBody reads and returns the response body
-// Returns error if body is empty
 func ReadResponseBody(resp *http.Response) ([]byte, error) {
 	if resp == nil {
 		return nil, fmt.Errorf("response is nil")
@@ -272,14 +256,12 @@ func ValidateResponse(resp *http.Response) error {
 	return nil
 }
 
-// BuildErrorMessage creates a detailed error message for API failures
 func BuildErrorMessage(apiURL string, statusCode int, responsePreview string) string {
 	msg := fmt.Sprintf("API %s failed", apiURL)
 	if statusCode > 0 {
 		msg += fmt.Sprintf(" (HTTP %d)", statusCode)
 	}
 	if responsePreview != "" {
-		// Truncate preview if too long
 		if len(responsePreview) > 100 {
 			responsePreview = responsePreview[:100] + "..."
 		}
@@ -298,18 +280,14 @@ func (e *ISPBlockingError) Error() string {
 	return fmt.Sprintf("ISP blocking detected for %s: %s", e.Domain, e.Reason)
 }
 
-// IsISPBlocking checks if an error is likely caused by ISP blocking
-// Returns the ISPBlockingError if detected, nil otherwise
 func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 	if err == nil {
 		return nil
 	}
 
-	// Extract domain from URL
 	domain := extractDomain(requestURL)
 	errStr := strings.ToLower(err.Error())
 
-	// Check for DNS resolution failure (common ISP blocking method)
 	var dnsErr *net.DNSError
 	if errors.As(err, &dnsErr) {
 		if dnsErr.IsNotFound || dnsErr.IsTemporary {
@@ -321,11 +299,9 @@ func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 		}
 	}
 
-	// Check for connection refused (ISP firewall blocking)
 	var opErr *net.OpError
 	if errors.As(err, &opErr) {
 		if opErr.Op == "dial" {
-			// Check for specific syscall errors
 			var syscallErr syscall.Errno
 			if errors.As(opErr.Err, &syscallErr) {
 				switch syscallErr {
@@ -364,7 +340,6 @@ func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 		}
 	}
 
-	// Check for TLS handshake failure (ISP MITM or blocking HTTPS)
 	var tlsErr *tls.RecordHeaderError
 	if errors.As(err, &tlsErr) {
 		return &ISPBlockingError{
@@ -425,7 +400,6 @@ func extractDomain(rawURL string) string {
 
 	parsed, err := url.Parse(rawURL)
 	if err != nil {
-		// Try to extract domain manually
 		rawURL = strings.TrimPrefix(rawURL, "https://")
 		rawURL = strings.TrimPrefix(rawURL, "http://")
 		if idx := strings.Index(rawURL, "/"); idx > 0 {

go_backend/lyrics.go

@@ -238,12 +238,9 @@ func (c *LyricsClient) durationMatches(lrcDuration, targetDuration float64) bool
 	return diff <= durationToleranceSec
 }
 
-// durationSec: track duration in seconds for matching, use 0 to skip duration matching
 func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName string, durationSec float64) (*LyricsResponse, error) {
-	// Normalize artist name - take first artist before comma/semicolon for better matching
 	primaryArtist := normalizeArtistName(artistName)
 
-	// Check cache first (use original artist name for cache key)
 	if cached, found := globalLyricsCache.Get(artistName, trackName, durationSec); found {
 		fmt.Printf("[Lyrics] Cache hit for: %s - %s\n", artistName, trackName)
 		cachedCopy := *cached
@@ -254,12 +251,10 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 	var lyrics *LyricsResponse
 	var err error
 
-	// Helper to check if lyrics result is valid (has lines OR is instrumental)
 	isValidResult := func(l *LyricsResponse) bool {
 		return l != nil && (len(l.Lines) > 0 || l.Instrumental)
 	}
 
-	// Try exact match first with primary artist
 	lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, trackName)
 	if err == nil && isValidResult(lyrics) {
 		lyrics.Source = "LRCLIB"
@@ -267,7 +262,6 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 		return lyrics, nil
 	}
 
-	// Try with full artist name if different from primary
 	if primaryArtist != artistName {
 		lyrics, err = c.FetchLyricsWithMetadata(artistName, trackName)
 		if err == nil && isValidResult(lyrics) {
@@ -277,7 +271,6 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 		}
 	}
 
-	// Try with simplified track name
 	simplifiedTrack := simplifyTrackName(trackName)
 	if simplifiedTrack != trackName {
 		lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, simplifiedTrack)
@@ -288,7 +281,6 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 		}
 	}
 
-	// Search with duration matching (use primary artist for search)
 	query := primaryArtist + " " + trackName
 	lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
 	if err == nil && isValidResult(lyrics) {
@@ -297,7 +289,6 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 		return lyrics, nil
 	}
 
-	// Search with simplified name and duration matching
 	if simplifiedTrack != trackName {
 		query = primaryArtist + " " + simplifiedTrack
 		lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
@@ -393,32 +384,6 @@ func msToLRCTimestamp(ms int64) string {
 	return fmt.Sprintf("[%02d:%02d.%02d]", minutes, seconds, centiseconds)
 }
 
-// Use convertToLRCWithMetadata for full LRC with headers
-// Kept for potential future use
-// func convertToLRC(lyrics *LyricsResponse) string {
-// 	if lyrics == nil || len(lyrics.Lines) == 0 {
-// 		return ""
-// 	}
-//
-// 	var builder strings.Builder
-//
-// 	if lyrics.SyncType == "LINE_SYNCED" {
-// 		for _, line := range lyrics.Lines {
-// 			timestamp := msToLRCTimestamp(line.StartTimeMs)
-// 			builder.WriteString(timestamp)
-// 			builder.WriteString(line.Words)
-// 			builder.WriteString("\n")
-// 		}
-// 	} else {
-// 		for _, line := range lyrics.Lines {
-// 			builder.WriteString(line.Words)
-// 			builder.WriteString("\n")
-// 		}
-// 	}
-//
-// 	return builder.String()
-// }
-
 func convertToLRCWithMetadata(lyrics *LyricsResponse, trackName, artistName string) string {
 	if lyrics == nil || len(lyrics.Lines) == 0 {
 		return ""
@@ -480,11 +445,7 @@ func simplifyTrackName(name string) string {
 	return strings.TrimSpace(result)
 }
 
-// normalizeArtistName extracts the primary artist from multi-artist strings
-// e.g., "HOYO-MiX, AURORA" -> "HOYO-MiX"
-// e.g., "Artist1; Artist2" -> "Artist1"
 func normalizeArtistName(name string) string {
-	// Split by common separators: ", " or "; " or " & " or " feat. " or " ft. "
 	separators := []string{", ", "; ", " & ", " feat. ", " ft. ", " featuring ", " with "}
 
 	result := name

go_backend/metadata.go

@@ -238,7 +238,6 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 	return f.Save(filePath)
 }
 
-// ReadMetadata reads metadata from a FLAC file
 func ReadMetadata(filePath string) (*Metadata, error) {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -336,6 +335,39 @@ func fileExists(path string) bool {
 	return err == nil
 }
 
+func ExtractCoverArt(filePath string) ([]byte, error) {
+	f, err := flac.ParseFile(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse FLAC file: %w", err)
+	}
+
+	for _, meta := range f.Meta {
+		if meta.Type == flac.Picture {
+			pic, err := flacpicture.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				continue
+			}
+			if pic.PictureType == flacpicture.PictureTypeFrontCover && len(pic.ImageData) > 0 {
+				return pic.ImageData, nil
+			}
+		}
+	}
+
+	for _, meta := range f.Meta {
+		if meta.Type == flac.Picture {
+			pic, err := flacpicture.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				continue
+			}
+			if len(pic.ImageData) > 0 {
+				return pic.ImageData, nil
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("no cover art found in file")
+}
+
 func EmbedLyrics(filePath string, lyrics string) error {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -418,7 +450,6 @@ func EmbedGenreLabel(filePath string, genre, label string) error {
 	return f.Save(filePath)
 }
 
-// ExtractLyrics extracts embedded lyrics from a FLAC file
 func ExtractLyrics(filePath string) (string, error) {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -512,356 +543,6 @@ func GetAudioQuality(filePath string) (AudioQuality, error) {
 	return AudioQuality{}, fmt.Errorf("unsupported file format (not FLAC or M4A)")
 }
 
-// ========================================
-// M4A (MP4/AAC) Metadata Embedding
-// ========================================
-
-// EmbedM4AMetadata embeds metadata into an M4A file using iTunes-style atoms
-func EmbedM4AMetadata(filePath string, metadata Metadata, coverData []byte) error {
-	input, err := os.Open(filePath)
-	if err != nil {
-		return fmt.Errorf("failed to open M4A file: %w", err)
-	}
-	defer input.Close()
-
-	info, err := input.Stat()
-	if err != nil {
-		return fmt.Errorf("failed to stat M4A file: %w", err)
-	}
-	fileSize := info.Size()
-
-	moovHeader, moovFound, err := findAtomInRange(input, 0, fileSize, "moov", fileSize)
-	if err != nil {
-		return fmt.Errorf("failed to find moov atom: %w", err)
-	}
-	if !moovFound {
-		return fmt.Errorf("moov atom not found in M4A file")
-	}
-
-	moovContentStart := moovHeader.offset + moovHeader.headerSize
-	moovContentSize := moovHeader.size - moovHeader.headerSize
-
-	udtaHeader, udtaFound, err := findAtomInRange(input, moovContentStart, moovContentSize, "udta", fileSize)
-	if err != nil {
-		return fmt.Errorf("failed to locate udta atom: %w", err)
-	}
-
-	var metaHeader atomHeader
-	metaFound := false
-	if udtaFound {
-		udtaContentStart := udtaHeader.offset + udtaHeader.headerSize
-		udtaContentSize := udtaHeader.size - udtaHeader.headerSize
-		metaHeader, metaFound, err = findAtomInRange(input, udtaContentStart, udtaContentSize, "meta", fileSize)
-		if err != nil {
-			return fmt.Errorf("failed to locate meta atom: %w", err)
-		}
-	}
-
-	metaAtom := buildMetaAtom(metadata, coverData)
-	metaSize := int64(len(metaAtom))
-
-	var delta int64
-	var newUdtaSize int64
-	switch {
-	case udtaFound && metaFound:
-		delta = metaSize - metaHeader.size
-		newUdtaSize = udtaHeader.size + delta
-	case udtaFound && !metaFound:
-		delta = metaSize
-		newUdtaSize = udtaHeader.size + delta
-	case !udtaFound:
-		newUdtaSize = int64(8 + len(metaAtom))
-		delta = newUdtaSize
-	}
-
-	newMoovSize := moovHeader.size + delta
-	if moovHeader.headerSize == 8 && newMoovSize > int64(^uint32(0)) {
-		return fmt.Errorf("moov atom exceeds 32-bit size after update")
-	}
-	if udtaFound && udtaHeader.headerSize == 8 && newUdtaSize > int64(^uint32(0)) {
-		return fmt.Errorf("udta atom exceeds 32-bit size after update")
-	}
-	if !udtaFound && newUdtaSize > int64(^uint32(0)) {
-		return fmt.Errorf("udta atom exceeds 32-bit size after update")
-	}
-
-	tempPath := filePath + ".tmp"
-	output, err := os.OpenFile(tempPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
-	if err != nil {
-		return fmt.Errorf("failed to create temp file: %w", err)
-	}
-	cleanupTemp := true
-	defer func() {
-		_ = output.Close()
-		if cleanupTemp {
-			_ = os.Remove(tempPath)
-		}
-	}()
-
-	switch {
-	case udtaFound && metaFound:
-		if err := copyRange(output, input, 0, moovHeader.offset); err != nil {
-			return err
-		}
-		if err := writeAtomHeader(output, "moov", newMoovSize, moovHeader.headerSize); err != nil {
-			return err
-		}
-		if err := copyRange(output, input, moovHeader.offset+moovHeader.headerSize, udtaHeader.offset-(moovHeader.offset+moovHeader.headerSize)); err != nil {
-			return err
-		}
-		if err := writeAtomHeader(output, "udta", newUdtaSize, udtaHeader.headerSize); err != nil {
-			return err
-		}
-		if err := copyRange(output, input, udtaHeader.offset+udtaHeader.headerSize, metaHeader.offset-(udtaHeader.offset+udtaHeader.headerSize)); err != nil {
-			return err
-		}
-		if _, err := output.Write(metaAtom); err != nil {
-			return fmt.Errorf("failed to write meta atom: %w", err)
-		}
-		metaEnd := metaHeader.offset + metaHeader.size
-		if err := copyRange(output, input, metaEnd, fileSize-metaEnd); err != nil {
-			return err
-		}
-	case udtaFound && !metaFound:
-		if err := copyRange(output, input, 0, moovHeader.offset); err != nil {
-			return err
-		}
-		if err := writeAtomHeader(output, "moov", newMoovSize, moovHeader.headerSize); err != nil {
-			return err
-		}
-		if err := copyRange(output, input, moovHeader.offset+moovHeader.headerSize, udtaHeader.offset-(moovHeader.offset+moovHeader.headerSize)); err != nil {
-			return err
-		}
-		if err := writeAtomHeader(output, "udta", newUdtaSize, udtaHeader.headerSize); err != nil {
-			return err
-		}
-		insertPos := udtaHeader.offset + udtaHeader.size
-		if err := copyRange(output, input, udtaHeader.offset+udtaHeader.headerSize, insertPos-(udtaHeader.offset+udtaHeader.headerSize)); err != nil {
-			return err
-		}
-		if _, err := output.Write(metaAtom); err != nil {
-			return fmt.Errorf("failed to write meta atom: %w", err)
-		}
-		if err := copyRange(output, input, insertPos, fileSize-insertPos); err != nil {
-			return err
-		}
-	case !udtaFound:
-		newUdtaAtom := buildUdtaAtom(metaAtom)
-		if err := copyRange(output, input, 0, moovHeader.offset); err != nil {
-			return err
-		}
-		if err := writeAtomHeader(output, "moov", newMoovSize, moovHeader.headerSize); err != nil {
-			return err
-		}
-		moovEnd := moovHeader.offset + moovHeader.size
-		if err := copyRange(output, input, moovHeader.offset+moovHeader.headerSize, moovEnd-(moovHeader.offset+moovHeader.headerSize)); err != nil {
-			return err
-		}
-		if _, err := output.Write(newUdtaAtom); err != nil {
-			return fmt.Errorf("failed to write udta atom: %w", err)
-		}
-		if err := copyRange(output, input, moovEnd, fileSize-moovEnd); err != nil {
-			return err
-		}
-	}
-
-	if err := output.Close(); err != nil {
-		return fmt.Errorf("failed to close temp file: %w", err)
-	}
-
-	_ = input.Close()
-	if err := os.Remove(filePath); err != nil {
-		return fmt.Errorf("failed to replace original file: %w", err)
-	}
-	if err := os.Rename(tempPath, filePath); err != nil {
-		return fmt.Errorf("failed to move temp file: %w", err)
-	}
-	cleanupTemp = false
-
-	fmt.Printf("[M4A] Metadata embedded successfully\n")
-	return nil
-}
-
-// buildMetaAtom builds a complete meta atom with ilst containing metadata
-func buildMetaAtom(metadata Metadata, coverData []byte) []byte {
-	var ilst []byte
-
-	if metadata.Title != "" {
-		ilst = append(ilst, buildTextAtom("©nam", metadata.Title)...)
-	}
-
-	if metadata.Artist != "" {
-		ilst = append(ilst, buildTextAtom("©ART", metadata.Artist)...)
-	}
-
-	if metadata.Album != "" {
-		ilst = append(ilst, buildTextAtom("©alb", metadata.Album)...)
-	}
-
-	if metadata.AlbumArtist != "" {
-		ilst = append(ilst, buildTextAtom("aART", metadata.AlbumArtist)...)
-	}
-
-	if metadata.Date != "" {
-		ilst = append(ilst, buildTextAtom("©day", metadata.Date)...)
-	}
-
-	if metadata.TrackNumber > 0 {
-		ilst = append(ilst, buildTrackNumberAtom(metadata.TrackNumber, metadata.TotalTracks)...)
-	}
-
-	if metadata.DiscNumber > 0 {
-		ilst = append(ilst, buildDiscNumberAtom(metadata.DiscNumber, 0)...)
-	}
-
-	if metadata.Lyrics != "" {
-		ilst = append(ilst, buildTextAtom("©lyr", metadata.Lyrics)...)
-	}
-
-	if len(coverData) > 0 {
-		ilst = append(ilst, buildCoverAtom(coverData)...)
-	}
-
-	ilstSize := 8 + len(ilst)
-	ilstAtom := make([]byte, 4)
-	ilstAtom[0] = byte(ilstSize >> 24)
-	ilstAtom[1] = byte(ilstSize >> 16)
-	ilstAtom[2] = byte(ilstSize >> 8)
-	ilstAtom[3] = byte(ilstSize)
-	ilstAtom = append(ilstAtom, []byte("ilst")...)
-	ilstAtom = append(ilstAtom, ilst...)
-
-	hdlr := []byte{
-		0, 0, 0, 33, // size = 33
-		'h', 'd', 'l', 'r',
-		0, 0, 0, 0, // version + flags
-		0, 0, 0, 0, // predefined
-		'm', 'd', 'i', 'r', // handler type
-		'a', 'p', 'p', 'l', // manufacturer
-		0, 0, 0, 0, // component flags
-		0, 0, 0, 0, // component flags mask
-		0, // null terminator
-	}
-
-	metaContent := append([]byte{0, 0, 0, 0}, hdlr...) // version + flags + hdlr
-	metaContent = append(metaContent, ilstAtom...)
-
-	metaSize := 8 + len(metaContent)
-	metaAtom := make([]byte, 4)
-	metaAtom[0] = byte(metaSize >> 24)
-	metaAtom[1] = byte(metaSize >> 16)
-	metaAtom[2] = byte(metaSize >> 8)
-	metaAtom[3] = byte(metaSize)
-	metaAtom = append(metaAtom, []byte("meta")...)
-	metaAtom = append(metaAtom, metaContent...)
-
-	return metaAtom
-}
-
-func buildTextAtom(name, value string) []byte {
-	valueBytes := []byte(value)
-
-	dataSize := 16 + len(valueBytes)
-	dataAtom := make([]byte, 4)
-	dataAtom[0] = byte(dataSize >> 24)
-	dataAtom[1] = byte(dataSize >> 16)
-	dataAtom[2] = byte(dataSize >> 8)
-	dataAtom[3] = byte(dataSize)
-	dataAtom = append(dataAtom, []byte("data")...)
-	dataAtom = append(dataAtom, 0, 0, 0, 1) // type = UTF-8
-	dataAtom = append(dataAtom, 0, 0, 0, 0) // locale
-	dataAtom = append(dataAtom, valueBytes...)
-
-	atomSize := 8 + len(dataAtom)
-	atom := make([]byte, 4)
-	atom[0] = byte(atomSize >> 24)
-	atom[1] = byte(atomSize >> 16)
-	atom[2] = byte(atomSize >> 8)
-	atom[3] = byte(atomSize)
-	atom = append(atom, []byte(name)...)
-	atom = append(atom, dataAtom...)
-
-	return atom
-}
-
-// buildTrackNumberAtom builds trkn atom
-func buildTrackNumberAtom(track, total int) []byte {
-	dataAtom := []byte{
-		0, 0, 0, 24, // size
-		'd', 'a', 't', 'a',
-		0, 0, 0, 0, // type = implicit
-		0, 0, 0, 0, // locale
-		0, 0, // padding
-		byte(track >> 8), byte(track), // track number
-		byte(total >> 8), byte(total), // total tracks
-		0, 0, // padding
-	}
-
-	atomSize := 8 + len(dataAtom)
-	atom := make([]byte, 4)
-	atom[0] = byte(atomSize >> 24)
-	atom[1] = byte(atomSize >> 16)
-	atom[2] = byte(atomSize >> 8)
-	atom[3] = byte(atomSize)
-	atom = append(atom, []byte("trkn")...)
-	atom = append(atom, dataAtom...)
-
-	return atom
-}
-
-func buildDiscNumberAtom(disc, total int) []byte {
-	dataAtom := []byte{
-		0, 0, 0, 22, // size
-		'd', 'a', 't', 'a',
-		0, 0, 0, 0, // type = implicit
-		0, 0, 0, 0, // locale
-		0, 0, // padding
-		byte(disc >> 8), byte(disc), // disc number
-		byte(total >> 8), byte(total), // total discs
-	}
-
-	atomSize := 8 + len(dataAtom)
-	atom := make([]byte, 4)
-	atom[0] = byte(atomSize >> 24)
-	atom[1] = byte(atomSize >> 16)
-	atom[2] = byte(atomSize >> 8)
-	atom[3] = byte(atomSize)
-	atom = append(atom, []byte("disk")...)
-	atom = append(atom, dataAtom...)
-
-	return atom
-}
-
-// buildCoverAtom builds covr atom with image data
-func buildCoverAtom(coverData []byte) []byte {
-	imageType := byte(13)
-	if len(coverData) > 8 && coverData[0] == 0x89 && coverData[1] == 'P' && coverData[2] == 'N' && coverData[3] == 'G' {
-		imageType = 14
-	}
-
-	dataSize := 16 + len(coverData)
-	dataAtom := make([]byte, 4)
-	dataAtom[0] = byte(dataSize >> 24)
-	dataAtom[1] = byte(dataSize >> 16)
-	dataAtom[2] = byte(dataSize >> 8)
-	dataAtom[3] = byte(dataSize)
-	dataAtom = append(dataAtom, []byte("data")...)
-	dataAtom = append(dataAtom, 0, 0, 0, imageType)
-	dataAtom = append(dataAtom, 0, 0, 0, 0)
-	dataAtom = append(dataAtom, coverData...)
-
-	atomSize := 8 + len(dataAtom)
-	atom := make([]byte, 4)
-	atom[0] = byte(atomSize >> 24)
-	atom[1] = byte(atomSize >> 16)
-	atom[2] = byte(atomSize >> 8)
-	atom[3] = byte(atomSize)
-	atom = append(atom, []byte("covr")...)
-	atom = append(atom, dataAtom...)
-
-	return atom
-}
-
 func GetM4AQuality(filePath string) (AudioQuality, error) {
 	f, err := os.Open(filePath)
 	if err != nil {
@@ -974,52 +655,6 @@ func findAtomInRange(f *os.File, start, size int64, target string, fileSize int6
 	return atomHeader{}, false, nil
 }
 
-func writeAtomHeader(w io.Writer, typ string, size int64, headerSize int64) error {
-	if len(typ) != 4 {
-		return fmt.Errorf("invalid atom type: %s", typ)
-	}
-
-	if headerSize == 16 {
-		header := make([]byte, 16)
-		binary.BigEndian.PutUint32(header[0:4], 1)
-		copy(header[4:8], []byte(typ))
-		binary.BigEndian.PutUint64(header[8:16], uint64(size))
-		_, err := w.Write(header)
-		return err
-	}
-
-	if size > int64(^uint32(0)) {
-		return fmt.Errorf("atom size exceeds 32-bit for %s", typ)
-	}
-
-	header := make([]byte, 8)
-	binary.BigEndian.PutUint32(header[0:4], uint32(size))
-	copy(header[4:8], []byte(typ))
-	_, err := w.Write(header)
-	return err
-}
-
-func copyRange(dst io.Writer, src *os.File, offset, length int64) error {
-	if length <= 0 {
-		return nil
-	}
-	if _, err := src.Seek(offset, io.SeekStart); err != nil {
-		return fmt.Errorf("failed to seek source: %w", err)
-	}
-	if _, err := io.CopyN(dst, src, length); err != nil {
-		return fmt.Errorf("failed to copy data: %w", err)
-	}
-	return nil
-}
-
-func buildUdtaAtom(metaAtom []byte) []byte {
-	size := 8 + len(metaAtom)
-	header := make([]byte, 8)
-	binary.BigEndian.PutUint32(header[0:4], uint32(size))
-	copy(header[4:8], []byte("udta"))
-	return append(header, metaAtom...)
-}
-
 func findAudioSampleEntry(f *os.File, start, end, fileSize int64) (int64, string, error) {
 	const chunkSize = 64 * 1024
 	patternMP4A := []byte("mp4a")

go_backend/parallel.go

@@ -14,10 +14,9 @@ type TrackIDCacheEntry struct {
 }
 
 type TrackIDCache struct {
-	cache map[string]*TrackIDCacheEntry
+	cache           map[string]*TrackIDCacheEntry
-	mu    sync.RWMutex
+	mu              sync.RWMutex
-	ttl   time.Duration
+	ttl             time.Duration
-	// Cleanup is triggered on writes at a fixed interval to avoid unbounded growth.
 	lastCleanup     time.Time
 	cleanupInterval time.Duration
 }
@@ -52,7 +51,6 @@ func (c *TrackIDCache) Get(isrc string) *TrackIDCacheEntry {
 		return entry
 	}
 
-	// Lazily delete expired entry.
 	c.mu.Lock()
 	entry, exists = c.cache[isrc]
 	if exists && time.Now().After(entry.ExpiresAt) {
@@ -139,7 +137,6 @@ func (c *TrackIDCache) Size() int {
 	return len(c.cache)
 }
 
-// ParallelDownloadResult holds results from parallel operations
 type ParallelDownloadResult struct {
 	CoverData  []byte
 	LyricsData *LyricsResponse
@@ -164,14 +161,11 @@ func FetchCoverAndLyricsParallel(
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			fmt.Println("[Parallel] Starting cover download...")
 			data, err := downloadCoverToMemory(coverURL, maxQualityCover)
 			if err != nil {
 				result.CoverErr = err
-				fmt.Printf("[Parallel] Cover download failed: %v\n", err)
 			} else {
 				result.CoverData = data
-				fmt.Printf("[Parallel] Cover downloaded: %d bytes\n", len(data))
 			}
 		}()
 	}
@@ -180,20 +174,16 @@ func FetchCoverAndLyricsParallel(
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			fmt.Println("[Parallel] Starting lyrics fetch...")
 			client := NewLyricsClient()
 			durationSec := float64(durationMs) / 1000.0
 			lyrics, err := client.FetchLyricsAllSources(spotifyID, trackName, artistName, durationSec)
 			if err != nil {
 				result.LyricsErr = err
-				fmt.Printf("[Parallel] Lyrics fetch failed: %v\n", err)
 			} else if lyrics != nil && len(lyrics.Lines) > 0 {
 				result.LyricsData = lyrics
 				result.LyricsLRC = convertToLRCWithMetadata(lyrics, trackName, artistName)
-				fmt.Printf("[Parallel] Lyrics fetched: %d lines\n", len(lyrics.Lines))
 			} else {
 				result.LyricsErr = fmt.Errorf("no lyrics found")
-				fmt.Println("[Parallel] No lyrics found")
 			}
 		}()
 	}
@@ -206,8 +196,8 @@ type PreWarmCacheRequest struct {
 	ISRC       string
 	TrackName  string
 	ArtistName string
-	SpotifyID  string // Needed for Amazon (SongLink lookup)
+	SpotifyID  string
-	Service    string // "tidal", "qobuz", "amazon"
+	Service    string
 }
 
 func PreWarmTrackCache(requests []PreWarmCacheRequest) {
@@ -215,7 +205,6 @@ func PreWarmTrackCache(requests []PreWarmCacheRequest) {
 		return
 	}
 
-	fmt.Printf("[Cache] Pre-warming cache for %d tracks...\n", len(requests))
 	cache := GetTrackIDCache()
 
 	semaphore := make(chan struct{}, 3)
@@ -244,7 +233,6 @@ func PreWarmTrackCache(requests []PreWarmCacheRequest) {
 	}
 
 	wg.Wait()
-	fmt.Printf("[Cache] Pre-warm complete. Cache size: %d\n", cache.Size())
 }
 
 func preWarmTidalCache(isrc, _, _ string) {
@@ -252,7 +240,6 @@ func preWarmTidalCache(isrc, _, _ string) {
 	track, err := downloader.SearchTrackByISRC(isrc)
 	if err == nil && track != nil {
 		GetTrackIDCache().SetTidal(isrc, track.ID)
-		fmt.Printf("[Cache] Cached Tidal ID for ISRC %s: %d\n", isrc, track.ID)
 	}
 }
 
@@ -261,7 +248,6 @@ func preWarmQobuzCache(isrc string) {
 	track, err := downloader.SearchTrackByISRC(isrc)
 	if err == nil && track != nil {
 		GetTrackIDCache().SetQobuz(isrc, track.ID)
-		fmt.Printf("[Cache] Cached Qobuz ID for ISRC %s: %d\n", isrc, track.ID)
 	}
 }
 
@@ -270,7 +256,6 @@ func preWarmAmazonCache(isrc, spotifyID string) {
 	availability, err := client.CheckTrackAvailability(spotifyID, isrc)
 	if err == nil && availability != nil && availability.Amazon {
 		GetTrackIDCache().SetAmazon(isrc, availability.AmazonURL)
-		fmt.Printf("[Cache] Cached Amazon URL for ISRC %s\n", isrc)
 	}
 }
 
@@ -283,7 +268,6 @@ func PreWarmCache(tracksJSON string) error {
 
 func ClearTrackCache() {
 	GetTrackIDCache().Clear()
-	fmt.Println("[Cache] Track ID cache cleared")
 }
 
 func GetCacheSize() int {

go_backend/progress.go

@@ -78,7 +78,6 @@ func GetItemProgress(itemID string) string {
 	return "{}"
 }
 
-// StartItemProgress initializes progress tracking for an item
 func StartItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -93,7 +92,6 @@ func StartItemProgress(itemID string) {
 	}
 }
 
-// SetItemBytesTotal sets total bytes for an item
 func SetItemBytesTotal(itemID string, total int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -103,7 +101,6 @@ func SetItemBytesTotal(itemID string, total int64) {
 	}
 }
 
-// SetItemBytesReceived sets bytes received for an item
 func SetItemBytesReceived(itemID string, received int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -116,7 +113,6 @@ func SetItemBytesReceived(itemID string, received int64) {
 	}
 }
 
-// SetItemBytesReceivedWithSpeed sets bytes received and speed for an item
 func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps float64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -130,7 +126,6 @@ func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps floa
 	}
 }
 
-// CompleteItemProgress marks an item as complete
 func CompleteItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -142,7 +137,6 @@ func CompleteItemProgress(itemID string) {
 	}
 }
 
-// SetItemProgress sets progress for an item directly
 func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -158,7 +152,6 @@ func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal
 	}
 }
 
-// SetItemFinalizing marks an item as finalizing (embedding metadata)
 func SetItemFinalizing(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -169,7 +162,6 @@ func SetItemFinalizing(itemID string) {
 	}
 }
 
-// RemoveItemProgress removes progress tracking for an item
 func RemoveItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -177,7 +169,6 @@ func RemoveItemProgress(itemID string) {
 	delete(multiProgress.Items, itemID)
 }
 
-// ClearAllItemProgress clears all item progress
 func ClearAllItemProgress() {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -185,7 +176,6 @@ func ClearAllItemProgress() {
 	multiProgress.Items = make(map[string]*ItemProgress)
 }
 
-// setDownloadDir sets the default download directory
 func setDownloadDir(path string) error {
 	downloadDirMu.Lock()
 	defer downloadDirMu.Unlock()
@@ -193,7 +183,6 @@ func setDownloadDir(path string) error {
 	return nil
 }
 
-// ItemProgressWriter wraps io.Writer to track download progress for a specific item
 type ItemProgressWriter struct {
 	writer       interface{ Write([]byte) (int, error) }
 	itemID       string
@@ -206,7 +195,6 @@ type ItemProgressWriter struct {
 
 const progressUpdateThreshold = 64 * 1024 // Update progress every 64KB
 
-// NewItemProgressWriter creates a new progress writer for a specific item
 func NewItemProgressWriter(w interface{ Write([]byte) (int, error) }, itemID string) *ItemProgressWriter {
 	now := time.Now()
 	return &ItemProgressWriter{
@@ -220,7 +208,6 @@ func NewItemProgressWriter(w interface{ Write([]byte) (int, error) }, itemID str
 	}
 }
 
-// Write implements io.Writer with threshold-based progress updates and speed tracking
 func (pw *ItemProgressWriter) Write(p []byte) (int, error) {
 	if pw.itemID != "" && isDownloadCancelled(pw.itemID) {
 		return 0, ErrDownloadCancelled

go_backend/qobuz.go

@@ -52,12 +52,10 @@ func qobuzArtistsMatch(expectedArtist, foundArtist string) bool {
 	normExpected := strings.ToLower(strings.TrimSpace(expectedArtist))
 	normFound := strings.ToLower(strings.TrimSpace(foundArtist))
 
-	// Exact match
 	if normExpected == normFound {
 		return true
 	}
 
-	// Check if one contains the other
 	if strings.Contains(normExpected, normFound) || strings.Contains(normFound, normExpected) {
 		return true
 	}
@@ -112,24 +110,19 @@ func qobuzSplitArtists(artists string) []string {
 	return result
 }
 
-// qobuzSameWordsUnordered checks if two strings have the same words regardless of order
-// Useful for Japanese names: "Sawano Hiroyuki" vs "Hiroyuki Sawano"
 func qobuzSameWordsUnordered(a, b string) bool {
 	wordsA := strings.Fields(a)
 	wordsB := strings.Fields(b)
 
-	// Must have same number of words
 	if len(wordsA) != len(wordsB) || len(wordsA) == 0 {
 		return false
 	}
 
-	// Sort and compare
 	sortedA := make([]string, len(wordsA))
 	sortedB := make([]string, len(wordsB))
 	copy(sortedA, wordsA)
 	copy(sortedB, wordsB)
 
-	// Simple bubble sort (usually just 2-3 words)
 	for i := 0; i < len(sortedA)-1; i++ {
 		for j := i + 1; j < len(sortedA); j++ {
 			if sortedA[i] > sortedA[j] {
@@ -153,7 +146,6 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 	normExpected := strings.ToLower(strings.TrimSpace(expectedTitle))
 	normFound := strings.ToLower(strings.TrimSpace(foundTitle))
 
-	// Exact match
 	if normExpected == normFound {
 		return true
 	}
@@ -182,8 +174,6 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 		return true
 	}
 
-	// If scripts are TRULY different (Latin vs CJK/Arabic/Cyrillic), assume match (transliteration)
-	// Don't treat Latin Extended (Polish, French, etc.) as different script
 	expectedLatin := qobuzIsLatinScript(expectedTitle)
 	foundLatin := qobuzIsLatinScript(foundTitle)
 	if expectedLatin != foundLatin {
@@ -194,9 +184,7 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 	return false
 }
 
-// qobuzExtractCoreTitle extracts the main title before any parentheses or brackets
 func qobuzExtractCoreTitle(title string) string {
-	// Find first occurrence of ( or [
 	parenIdx := strings.Index(title, "(")
 	bracketIdx := strings.Index(title, "[")
 	dashIdx := strings.Index(title, " - ")
@@ -281,49 +269,28 @@ func qobuzCleanTitle(title string) string {
 	return strings.TrimSpace(cleaned)
 }
 
-// qobuzIsLatinScript checks if a string is primarily Latin script
-// Returns true for ASCII and Latin Extended characters (European languages)
-// Returns false for CJK, Arabic, Cyrillic, etc.
 func qobuzIsLatinScript(s string) bool {
 	for _, r := range s {
-		// Skip common punctuation and numbers
 		if r < 128 {
 			continue
 		}
-		// Latin Extended-A: U+0100 to U+017F (Polish, Czech, etc.)
+		if (r >= 0x0100 && r <= 0x024F) ||
-		// Latin Extended-B: U+0180 to U+024F
+			(r >= 0x1E00 && r <= 0x1EFF) ||
-		// Latin Extended Additional: U+1E00 to U+1EFF
+			(r >= 0x00C0 && r <= 0x00FF) {
-		// Latin Extended-C/D/E: various ranges
-		if (r >= 0x0100 && r <= 0x024F) || // Latin Extended A & B
-			(r >= 0x1E00 && r <= 0x1EFF) || // Latin Extended Additional
-			(r >= 0x00C0 && r <= 0x00FF) { // Latin-1 Supplement (accented chars)
 			continue
 		}
-		// CJK ranges - definitely different script
+		if (r >= 0x4E00 && r <= 0x9FFF) ||
-		if (r >= 0x4E00 && r <= 0x9FFF) || // CJK Unified Ideographs
+			(r >= 0x3040 && r <= 0x309F) ||
-			(r >= 0x3040 && r <= 0x309F) || // Hiragana
+			(r >= 0x30A0 && r <= 0x30FF) ||
-			(r >= 0x30A0 && r <= 0x30FF) || // Katakana
+			(r >= 0xAC00 && r <= 0xD7AF) ||
-			(r >= 0xAC00 && r <= 0xD7AF) || // Hangul (Korean)
+			(r >= 0x0600 && r <= 0x06FF) ||
-			(r >= 0x0600 && r <= 0x06FF) || // Arabic
+			(r >= 0x0400 && r <= 0x04FF) {
-			(r >= 0x0400 && r <= 0x04FF) { // Cyrillic
 			return false
 		}
 	}
 	return true
 }
 
-// qobuzIsASCIIString checks if a string contains only ASCII characters
-// Kept for potential future use
-// func qobuzIsASCIIString(s string) bool {
-// 	for _, r := range s {
-// 		if r > 127 {
-// 			return false
-// 		}
-// 	}
-// 	return true
-// }
-
-// containsQueryQobuz checks if a query already exists in the list
 func containsQueryQobuz(queries []string, query string) bool {
 	for _, q := range queries {
 		if q == query {
@@ -336,7 +303,7 @@ func containsQueryQobuz(queries []string, query string) bool {
 func NewQobuzDownloader() *QobuzDownloader {
 	qobuzDownloaderOnce.Do(func() {
 		globalQobuzDownloader = &QobuzDownloader{
-			client: NewHTTPClientWithTimeout(DefaultTimeout), // 60s timeout
+			client: NewHTTPClientWithTimeout(DefaultTimeout),
 			appID:  "798273057",
 		}
 	})
@@ -344,7 +311,6 @@ func NewQobuzDownloader() *QobuzDownloader {
 }
 
 func (q *QobuzDownloader) GetTrackByID(trackID int64) (*QobuzTrack, error) {
-	// Qobuz API: /track/get?track_id=XXX
 	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9nZXQ/dHJhY2tfaWQ9")
 	trackURL := fmt.Sprintf("%s%d&app_id=%s", string(apiBase), trackID, q.appID)
 
@@ -371,15 +337,11 @@ func (q *QobuzDownloader) GetTrackByID(trackID int64) (*QobuzTrack, error) {
 	return &track, nil
 }
 
-// GetAvailableAPIs returns list of available Qobuz APIs
-// Uses same APIs as PC version for compatibility
 func (q *QobuzDownloader) GetAvailableAPIs() []string {
-	// Same APIs as PC version (referensi/backend/qobuz.go)
-	// Primary: dab.yeet.su, Fallback: dabmusic.xyz, qobuz.squid.wtf
 	encodedAPIs := []string{
-		"ZGFiLnllZXQuc3UvYXBpL3N0cmVhbT90cmFja0lkPQ==",                 // dab.yeet.su/api/stream?trackId=
+		"ZGFiLnllZXQuc3UvYXBpL3N0cmVhbT90cmFja0lkPQ==",
-		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=",                 // dabmusic.xyz/api/stream?trackId=
+		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=",
-		"cW9idXouc3F1aWQud3RmL2FwaS9kb3dubG9hZC1tdXNpYz90cmFja19pZD0=", // qobuz.squid.wtf/api/download-music?track_id=
+		"cW9idXouc3F1aWQud3RmL2FwaS9kb3dubG9hZC1tdXNpYz90cmFja19pZD0=",
 	}
 
 	var apis []string
@@ -394,21 +356,19 @@ func (q *QobuzDownloader) GetAvailableAPIs() []string {
 	return apis
 }
 
-// mapJumoQuality maps Qobuz quality codes to Jumo format
 func mapJumoQuality(quality string) int {
 	switch quality {
 	case "6":
-		return 6 // 16-bit FLAC
+		return 6
 	case "7":
-		return 7 // 24-bit 96kHz
+		return 7
 	case "27":
-		return 27 // 24-bit 192kHz
+		return 27
 	default:
 		return 6
 	}
 }
 
-// decodeXOR decodes XOR-encoded response from Jumo API
 func decodeXOR(data []byte) string {
 	text := string(data)
 	runes := []rune(text)
@@ -420,12 +380,9 @@ func decodeXOR(data []byte) string {
 	return string(result)
 }
 
-// downloadFromJumo gets download URL from Jumo API (fallback)
 func (q *QobuzDownloader) downloadFromJumo(trackID int64, quality string) (string, error) {
 	formatID := mapJumoQuality(quality)
 	region := "US"
-
-	// Jumo API endpoint
 	jumoURL := fmt.Sprintf("https://jumo-dl.pages.dev/file?track_id=%d&format_id=%d&region=%s", trackID, formatID, region)
 
 	GoLog("[Qobuz] Trying Jumo API fallback...\n")
@@ -452,17 +409,13 @@ func (q *QobuzDownloader) downloadFromJumo(trackID int64, quality string) (strin
 	}
 
 	var result map[string]any
-
-	// Try parsing as plain JSON first
 	if err := json.Unmarshal(body, &result); err != nil {
-		// Try XOR decoding
 		decoded := decodeXOR(body)
 		if err := json.Unmarshal([]byte(decoded), &result); err != nil {
 			return "", fmt.Errorf("failed to parse Jumo response (plain or XOR): %w", err)
 		}
 	}
 
-	// Check for URL in various response formats
 	if urlVal, ok := result["url"].(string); ok && urlVal != "" {
 		GoLog("[Qobuz] Jumo API returned URL successfully\n")
 		return urlVal, nil
@@ -511,7 +464,6 @@ func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 		return nil, err
 	}
 
-	// Find exact ISRC match
 	for i := range result.Tracks.Items {
 		if result.Tracks.Items[i].ISRC == isrc {
 			return &result.Tracks.Items[i], nil
@@ -525,7 +477,6 @@ func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
 }
 
-// expectedDurationSec is the expected duration in seconds (0 to skip verification)
 func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDurationSec int) (*QobuzTrack, error) {
 	GoLog("[Qobuz] Searching by ISRC: %s\n", isrc)
 
@@ -558,7 +509,6 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 
 	GoLog("[Qobuz] ISRC search returned %d results\n", len(result.Tracks.Items))
 
-	// Find ISRC matches
 	var isrcMatches []*QobuzTrack
 	for i := range result.Tracks.Items {
 		if result.Tracks.Items[i].ISRC == isrc {
@@ -612,35 +562,26 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 	return q.SearchTrackByMetadataWithDuration(trackName, artistName, 0)
 }
 
-// Now includes romaji conversion for Japanese text (same as Tidal)
-// Also includes title verification to prevent wrong song downloads
 func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistName string, expectedDurationSec int) (*QobuzTrack, error) {
 	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
 
-	// Try multiple search strategies (same as Tidal/PC version)
 	queries := []string{}
 
-	// Strategy 1: Artist + Track name
 	if artistName != "" && trackName != "" {
 		queries = append(queries, artistName+" "+trackName)
 	}
 
-	// Strategy 2: Track name only
 	if trackName != "" {
 		queries = append(queries, trackName)
 	}
 
-	// Strategy 3: Romaji versions if Japanese detected
 	if ContainsJapanese(trackName) || ContainsJapanese(artistName) {
-		// Convert to romaji (hiragana/katakana only, kanji stays)
 		romajiTrack := JapaneseToRomaji(trackName)
 		romajiArtist := JapaneseToRomaji(artistName)
 
-		// Clean and remove ALL non-ASCII characters (including kanji)
 		cleanRomajiTrack := CleanToASCII(romajiTrack)
 		cleanRomajiArtist := CleanToASCII(romajiArtist)
 
-		// Artist + Track romaji (cleaned to ASCII only)
 		if cleanRomajiArtist != "" && cleanRomajiTrack != "" {
 			romajiQuery := cleanRomajiArtist + " " + cleanRomajiTrack
 			if !containsQueryQobuz(queries, romajiQuery) {
@@ -649,7 +590,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 			}
 		}
 
-		// Track romaji only (cleaned)
 		if cleanRomajiTrack != "" && cleanRomajiTrack != trackName {
 			if !containsQueryQobuz(queries, cleanRomajiTrack) {
 				queries = append(queries, cleanRomajiTrack)
@@ -657,7 +597,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		}
 	}
 
-	// Strategy 4: Artist only as last resort
 	if artistName != "" {
 		artistOnly := CleanToASCII(JapaneseToRomaji(artistName))
 		if artistOnly != "" && !containsQueryQobuz(queries, artistOnly) {
@@ -716,7 +655,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		return nil, fmt.Errorf("no tracks found for: %s - %s", artistName, trackName)
 	}
 
-	// Filter by title match first (NEW - like Tidal)
 	var titleMatches []*QobuzTrack
 	for i := range allTracks {
 		track := &allTracks[i]
@@ -727,7 +665,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 
 	GoLog("[Qobuz] Title matches: %d out of %d results\n", len(titleMatches), len(allTracks))
 
-	// If no title matches, log warning but continue with all tracks
 	tracksToCheck := titleMatches
 	if len(titleMatches) == 0 {
 		GoLog("[Qobuz] WARNING: No title matches for '%s', checking all %d results\n", trackName, len(allTracks))
@@ -736,7 +673,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		}
 	}
 
-	// If duration verification is requested
 	if expectedDurationSec > 0 {
 		var durationMatches []*QobuzTrack
 		for _, track := range tracksToCheck {
@@ -765,7 +701,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		return nil, fmt.Errorf("no tracks found with matching title and duration (expected '%s', %ds)", trackName, expectedDurationSec)
 	}
 
-	// No duration verification, return best quality from title matches
 	for _, track := range tracksToCheck {
 		if track.MaximumBitDepth >= 24 {
 			GoLog("[Qobuz] Match found: '%s' by '%s' (title verified, hi-res)\n",
@@ -783,7 +718,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 	return nil, fmt.Errorf("no matching track found for: %s - %s", artistName, trackName)
 }
 
-// qobuzAPIResult holds the result from a parallel API request
 type qobuzAPIResult struct {
 	apiURL      string
 	downloadURL string
@@ -801,7 +735,6 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 	resultChan := make(chan qobuzAPIResult, len(apis))
 	startTime := time.Now()
 
-	// Start all requests in parallel
 	for _, apiURL := range apis {
 		go func(api string) {
 			reqStart := time.Now()
@@ -834,13 +767,11 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 				return
 			}
 
-			// Check if response is HTML (error page)
 			if len(body) > 0 && body[0] == '<' {
 				resultChan <- qobuzAPIResult{apiURL: api, err: fmt.Errorf("received HTML instead of JSON"), duration: time.Since(reqStart)}
 				return
 			}
 
-			// Check for error in JSON response
 			var errorResp struct {
 				Error string `json:"error"`
 			}
@@ -866,7 +797,6 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 		}(apiURL)
 	}
 
-	// Collect results - return first success
 	var errors []string
 
 	for i := 0; i < len(apis); i++ {
@@ -874,7 +804,6 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 		if result.err == nil {
 			GoLog("[Qobuz] [Parallel] Got response from %s in %v\n", result.apiURL, result.duration)
 
-			// Drain remaining results to avoid goroutine leaks
 			go func(remaining int) {
 				for j := 0; j < remaining; j++ {
 					<-resultChan
@@ -906,14 +835,12 @@ func (q *QobuzDownloader) GetDownloadURL(trackID int64, quality string) (string,
 		return downloadURL, nil
 	}
 
-	// All standard APIs failed, try Jumo as fallback
 	GoLog("[Qobuz] Standard APIs failed, trying Jumo fallback...\n")
 	jumoURL, jumoErr := q.downloadFromJumo(trackID, quality)
 	if jumoErr == nil {
 		return jumoURL, nil
 	}
 
-	// If quality is 27 (hi-res), try fallback to lower quality
 	if quality == "27" {
 		GoLog("[Qobuz] Hi-res (27) failed, trying 24-bit (7)...\n")
 		jumoURL, jumoErr = q.downloadFromJumo(trackID, "7")
@@ -933,11 +860,9 @@ func (q *QobuzDownloader) GetDownloadURL(trackID int64, quality string) (string,
 	return "", fmt.Errorf("all Qobuz APIs and Jumo fallback failed: %w", err)
 }
 
-// DownloadFile downloads a file from URL with User-Agent and progress tracking
 func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
 	ctx := context.Background()
 
-	// Initialize item progress (required for all downloads)
 	if itemID != "" {
 		StartItemProgress(itemID)
 		defer CompleteItemProgress(itemID)
@@ -987,7 +912,6 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		written, err = io.Copy(bufWriter, resp.Body)
 	}
 
-	// Flush buffer before checking for errors
 	flushErr := bufWriter.Flush()
 	closeErr := out.Close()
 
@@ -1007,7 +931,6 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
-	// Verify file size if Content-Length was provided
 	if expectedSize > 0 && written != expectedSize {
 		os.Remove(outputPath)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
@@ -1055,11 +978,9 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		}
 	}
 
-	// OPTIMIZATION: Check cache first for track ID
 	if track == nil && req.ISRC != "" {
 		if cached := GetTrackIDCache().Get(req.ISRC); cached != nil && cached.QobuzTrackID > 0 {
 			GoLog("[Qobuz] Cache hit! Using cached track ID: %d\n", cached.QobuzTrackID)
-			// For Qobuz we need to search again to get full track info, but we can use the ID
 			track, err = downloader.SearchTrackByISRC(req.ISRC)
 			if err != nil {
 				GoLog("[Qobuz] Cache hit but search failed: %v\n", err)
@@ -1068,11 +989,9 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		}
 	}
 
-	// Strategy 1: Search by ISRC with duration verification
 	if track == nil && req.ISRC != "" {
 		GoLog("[Qobuz] Trying ISRC search: %s\n", req.ISRC)
 		track, err = downloader.SearchTrackByISRCWithDuration(req.ISRC, expectedDurationSec)
-		// Verify artist AND title
 		if track != nil {
 			if !qobuzArtistsMatch(req.ArtistName, track.Performer.Name) {
 				GoLog("[Qobuz] Artist mismatch from ISRC search: expected '%s', got '%s'. Rejecting.\n",
@@ -1086,10 +1005,8 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		}
 	}
 
-	// Strategy 2: Search by metadata with duration verification (includes title verification)
 	if track == nil {
 		track, err = downloader.SearchTrackByMetadataWithDuration(req.TrackName, req.ArtistName, expectedDurationSec)
-		// Verify artist (title already verified in SearchTrackByMetadataWithDuration)
 		if track != nil && !qobuzArtistsMatch(req.ArtistName, track.Performer.Name) {
 			GoLog("[Qobuz] Artist mismatch from metadata search: expected '%s', got '%s'. Rejecting.\n",
 				req.ArtistName, track.Performer.Name)
@@ -1105,7 +1022,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{}, fmt.Errorf("qobuz search failed: %s", errMsg)
 	}
 
-	// Log match found and cache the track ID
 	GoLog("[Qobuz] Match found: '%s' by '%s' (duration: %ds)\n", track.Title, track.Performer.Name, track.Duration)
 	if req.ISRC != "" {
 		GetTrackIDCache().SetQobuz(req.ISRC, track.ID)
@@ -1126,22 +1042,19 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
 
-	// Map quality from Tidal format to Qobuz format
+	qobuzQuality := "27"
-	// Tidal: LOSSLESS (16-bit), HI_RES (24-bit), HI_RES_LOSSLESS (24-bit hi-res)
-	// Qobuz: 5 (MP3 320), 6 (16-bit), 7 (24-bit 96kHz), 27 (24-bit 192kHz)
-	qobuzQuality := "27" // Default to highest quality
 	switch req.Quality {
 	case "LOSSLESS":
-		qobuzQuality = "6" // 16-bit FLAC
+		qobuzQuality = "6"
 	case "HI_RES":
-		qobuzQuality = "7" // 24-bit 96kHz
+		qobuzQuality = "7"
 	case "HI_RES_LOSSLESS":
-		qobuzQuality = "27" // 24-bit 192kHz
+		qobuzQuality = "27"
 	}
 	GoLog("[Qobuz] Using quality: %s (mapped from %s)\n", qobuzQuality, req.Quality)
 
 	actualBitDepth := track.MaximumBitDepth
-	actualSampleRate := int(track.MaximumSamplingRate * 1000) // Convert kHz to Hz
+	actualSampleRate := int(track.MaximumSamplingRate * 1000)
 	GoLog("[Qobuz] Actual quality: %d-bit/%.1fkHz\n", actualBitDepth, track.MaximumSamplingRate)
 
 	downloadURL, err := downloader.GetDownloadURL(track.ID, qobuzQuality)
@@ -1149,7 +1062,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{}, fmt.Errorf("failed to get download URL: %w", err)
 	}
 
-	// START PARALLEL: Fetch cover and lyrics while downloading audio
 	var parallelResult *ParallelDownloadResult
 	parallelDone := make(chan struct{})
 	go func() {
@@ -1165,7 +1077,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		)
 	}()
 
-	// Download audio file with item ID for progress tracking
 	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
 		if errors.Is(err, ErrDownloadCancelled) {
 			return QobuzDownloadResult{}, ErrDownloadCancelled
@@ -1173,7 +1084,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{}, fmt.Errorf("download failed: %w", err)
 	}
 
-	// Wait for parallel operations to complete
 	<-parallelDone
 
 	if req.ItemID != "" {
@@ -1186,7 +1096,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		albumName = req.AlbumName
 	}
 
-	// Use track number from request if available, otherwise from Qobuz API
 	actualTrackNumber := req.TrackNumber
 	if actualTrackNumber == 0 {
 		actualTrackNumber = track.TrackNumber
@@ -1196,15 +1105,15 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		Title:       track.Title,
 		Artist:      track.Performer.Name,
 		Album:       albumName,
-		AlbumArtist: req.AlbumArtist, // Qobuz track struct might not have this handy, keep req or check album struct
+		AlbumArtist: req.AlbumArtist,
 		Date:        track.Album.ReleaseDate,
 		TrackNumber: actualTrackNumber,
 		TotalTracks: req.TotalTracks,
-		DiscNumber:  req.DiscNumber, // QobuzTrack struct usually doesn't have disc info in simple search result
+		DiscNumber:  req.DiscNumber,
 		ISRC:        track.ISRC,
-		Genre:       req.Genre,     // From Deezer album metadata
+		Genre:       req.Genre,
-		Label:       req.Label,     // From Deezer album metadata
+		Label:       req.Label,
-		Copyright:   req.Copyright, // From Deezer album metadata
+		Copyright:   req.Copyright,
 	}
 
 	var coverData []byte
@@ -1244,7 +1153,6 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		fmt.Println("[Qobuz] No lyrics available from parallel fetch")
 	}
 
-	// Add to ISRC index for fast duplicate checking
 	AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
 
 	return QobuzDownloadResult{
@@ -1256,7 +1164,7 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		Album:       track.Album.Title,
 		ReleaseDate: track.Album.ReleaseDate,
 		TrackNumber: actualTrackNumber,
-		DiscNumber:  req.DiscNumber, // Qobuz track struct limitations
+		DiscNumber:  req.DiscNumber,
 		ISRC:        track.ISRC,
 	}, nil
 }

go_backend/songlink.go

@@ -43,33 +43,6 @@ func NewSongLinkClient() *SongLinkClient {
 }
 
 func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc string) (*TrackAvailability, error) {
-	if spotifyTrackID == "" {
-		return nil, fmt.Errorf("spotify track ID is empty")
-	}
-
-	// Try SongLink first
-	availability, err := s.checkTrackAvailabilitySongLink(spotifyTrackID)
-	if err != nil {
-		// Fallback to IDHS if SongLink fails
-		LogWarn("SongLink", "SongLink failed, trying IDHS fallback: %v", err)
-		idhsClient := NewIDHSClient()
-		availability, err = idhsClient.GetAvailabilityFromSpotify(spotifyTrackID)
-		if err != nil {
-			return nil, fmt.Errorf("both SongLink and IDHS failed: %w", err)
-		}
-		LogInfo("SongLink", "IDHS fallback successful for %s", spotifyTrackID)
-	}
-
-	// Check Qobuz availability separately via ISRC
-	if isrc != "" {
-		availability.Qobuz = checkQobuzAvailability(isrc)
-	}
-
-	return availability, nil
-}
-
-// checkTrackAvailabilitySongLink is the original SongLink implementation
-func (s *SongLinkClient) checkTrackAvailabilitySongLink(spotifyTrackID string) (*TrackAvailability, error) {
 	songLinkRateLimiter.WaitForSlot()
 
 	spotifyBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9vcGVuLnNwb3RpZnkuY29tL3RyYWNrLw==")
@@ -227,10 +200,8 @@ type AlbumAvailability struct {
 }
 
 func (s *SongLinkClient) CheckAlbumAvailability(spotifyAlbumID string) (*AlbumAvailability, error) {
-	// Use global rate limiter
 	songLinkRateLimiter.WaitForSlot()
 
-	// Build API URL for album
 	spotifyBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9vcGVuLnNwb3RpZnkuY29tL2FsYnVtLw==")
 	spotifyURL := fmt.Sprintf("%s%s", string(spotifyBase), spotifyAlbumID)
 
@@ -301,10 +272,8 @@ func (s *SongLinkClient) CheckAvailabilityFromDeezer(deezerTrackID string) (*Tra
 		return nil, fmt.Errorf("deezer track ID is empty")
 	}
 
-	// Try SongLink first
 	availability, err := s.checkAvailabilityFromDeezerSongLink(deezerTrackID)
 	if err != nil {
-		// Fallback to IDHS if SongLink fails
 		LogWarn("SongLink", "SongLink failed for Deezer, trying IDHS fallback: %v", err)
 		idhsClient := NewIDHSClient()
 		availability, err = idhsClient.GetAvailabilityFromDeezer(deezerTrackID)
@@ -338,7 +307,6 @@ func (s *SongLinkClient) checkAvailabilityFromDeezerSongLink(deezerTrackID strin
 	}
 	defer resp.Body.Close()
 
-	// Handle specific error codes
 	if resp.StatusCode == 400 {
 		return nil, fmt.Errorf("track not found on SongLink (invalid Deezer ID)")
 	}
@@ -407,11 +375,8 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 		return nil, fmt.Errorf("%s ID is empty", platform)
 	}
 
-	// Use global rate limiter
 	songLinkRateLimiter.WaitForSlot()
 
-	// Build API URL using platform, type, and id parameters (as per API docs)
-	// https://api.song.link/v1-alpha.1/links?platform=deezer&type=song&id=123456
 	apiURL := fmt.Sprintf("https://api.song.link/v1-alpha.1/links?platform=%s&type=%s&id=%s&userCountry=US",
 		url.QueryEscape(platform),
 		url.QueryEscape(entityType),
@@ -429,7 +394,6 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 	}
 	defer resp.Body.Close()
 
-	// Handle specific error codes
 	if resp.StatusCode == 400 {
 		return nil, fmt.Errorf("track not found on SongLink (invalid %s ID)", platform)
 	}

go_backend/spotify.go

@@ -66,7 +66,6 @@ var (
 // ErrNoSpotifyCredentials is returned when Spotify credentials are not configured
 var ErrNoSpotifyCredentials = errors.New("Spotify credentials not configured. Please set your own Client ID and Secret in Settings, or use Deezer as metadata source (free, no credentials required)")
 
-// SetSpotifyCredentials sets custom Spotify API credentials
 func SetSpotifyCredentials(clientID, clientSecret string) {
 	credentialsMu.Lock()
 	defer credentialsMu.Unlock()
@@ -89,7 +88,6 @@ func HasSpotifyCredentials() bool {
 	return false
 }
 
-// getCredentials returns the current credentials or error if not configured
 func getCredentials() (string, string, error) {
 	credentialsMu.RLock()
 	defer credentialsMu.RUnlock()

go_backend/tidal.go

@@ -119,19 +119,18 @@ func NewTidalDownloader() *TidalDownloader {
 	return globalTidalDownloader
 }
 
-// GetAvailableAPIs returns list of available Tidal APIs
 func (t *TidalDownloader) GetAvailableAPIs() []string {
 	encodedAPIs := []string{
+		"dGlkYWwtYXBpLmJpbmltdW0ub3Jn",     // tidal-api.binimum.org (priority)
 		"dGlkYWwua2lub3BsdXMub25saW5l",     // tidal.kinoplus.online
-		"dGlkYWwtYXBpLmJpbmltdW0ub3Jn",     // tidal-api.binimum.org
 		"dHJpdG9uLnNxdWlkLnd0Zg==",         // triton.squid.wtf
-		"aGlmaS1vbmUuc3BvdGlzYXZlci5uZXQ=", // hifi-one.spotisaver.net
-		"aGlmaS10d28uc3BvdGlzYXZlci5uZXQ=", // hifi-two.spotisaver.net
 		"dm9nZWwucXFkbC5zaXRl",             // vogel.qqdl.site
 		"bWF1cy5xcWRsLnNpdGU=",             // maus.qqdl.site
 		"aHVuZC5xcWRsLnNpdGU=",             // hund.qqdl.site
 		"a2F0emUucXFkbC5zaXRl",             // katze.qqdl.site
 		"d29sZi5xcWRsLnNpdGU=",             // wolf.qqdl.site
+		"aGlmaS1vbmUuc3BvdGlzYXZlci5uZXQ=", // hifi-one.spotisaver.net
+		"aGlmaS10d28uc3BvdGlzYXZlci5uZXQ=", // hifi-two.spotisaver.net
 	}
 
 	var apis []string
@@ -251,7 +250,6 @@ func (t *TidalDownloader) GetTrackIDFromURL(tidalURL string) (int64, error) {
 	return trackID, nil
 }
 
-// GetTrackInfoByID gets track info by Tidal track ID
 func (t *TidalDownloader) GetTrackInfoByID(trackID int64) (*TidalTrack, error) {
 	token, err := t.GetAccessToken()
 	if err != nil {
@@ -797,7 +795,6 @@ func parseManifest(manifestB64 string) (directURL string, initURL string, mediaU
 	return "", initURL, mediaURLs, nil
 }
 
-// DownloadFile downloads a file from URL with progress tracking
 func (t *TidalDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
 	ctx := context.Background()
 
@@ -970,7 +967,15 @@ func (t *TidalDownloader) downloadFromManifest(ctx context.Context, manifestB64,
 		return nil
 	}
 
-	m4aPath := strings.TrimSuffix(outputPath, ".flac") + ".m4a"
+	// For DASH format, determine correct M4A path
+	// If outputPath already ends with .m4a, use it directly
+	// Otherwise, convert .flac to .m4a
+	var m4aPath string
+	if strings.HasSuffix(outputPath, ".m4a") {
+		m4aPath = outputPath
+	} else {
+		m4aPath = strings.TrimSuffix(outputPath, ".flac") + ".m4a"
+	}
 	GoLog("[Tidal] DASH format - downloading %d segments directly to: %s\n", len(mediaURLs), m4aPath)
 
 	out, err := os.Create(m4aPath)
@@ -1096,6 +1101,7 @@ type TidalDownloadResult struct {
 	TrackNumber int
 	DiscNumber  int
 	ISRC        string
+	LyricsLRC   string // LRC content for embedding in converted files
 }
 
 func artistsMatch(spotifyArtist, tidalArtist string) bool {
@@ -1106,7 +1112,6 @@ func artistsMatch(spotifyArtist, tidalArtist string) bool {
 		return true
 	}
 
-	// Check if one contains the other (for cases like "Artist" vs "Artist feat. Someone")
 	if strings.Contains(normSpotify, normTidal) || strings.Contains(normTidal, normSpotify) {
 		return true
 	}
@@ -1165,7 +1170,6 @@ func sameWordsUnordered(a, b string) bool {
 	wordsA := strings.Fields(a)
 	wordsB := strings.Fields(b)
 
-	// Must have same number of words
 	if len(wordsA) != len(wordsB) || len(wordsA) == 0 {
 		return false
 	}
@@ -1198,7 +1202,6 @@ func titlesMatch(expectedTitle, foundTitle string) bool {
 	normExpected := strings.ToLower(strings.TrimSpace(expectedTitle))
 	normFound := strings.ToLower(strings.TrimSpace(foundTitle))
 
-	// Exact match
 	if normExpected == normFound {
 		return true
 	}
@@ -1207,7 +1210,6 @@ func titlesMatch(expectedTitle, foundTitle string) bool {
 		return true
 	}
 
-	// Clean both titles and compare
 	cleanExpected := cleanTitle(normExpected)
 	cleanFound := cleanTitle(normFound)
 
@@ -1221,7 +1223,6 @@ func titlesMatch(expectedTitle, foundTitle string) bool {
 		}
 	}
 
-	// Extract core title (before any parentheses/brackets)
 	coreExpected := extractCoreTitle(normExpected)
 	coreFound := extractCoreTitle(normFound)
 
@@ -1229,7 +1230,6 @@ func titlesMatch(expectedTitle, foundTitle string) bool {
 		return true
 	}
 
-	// Don't treat Latin Extended (Polish, French, etc.) as different script
 	expectedLatin := isLatinScript(expectedTitle)
 	foundLatin := isLatinScript(foundTitle)
 	if expectedLatin != foundLatin {
@@ -1502,6 +1502,11 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		GetTrackIDCache().SetTidal(req.ISRC, track.ID)
 	}
 
+	quality := req.Quality
+	if quality == "" {
+		quality = "LOSSLESS"
+	}
+
 	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
 		"title":  req.TrackName,
 		"artist": req.ArtistName,
@@ -1510,15 +1515,26 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		"year":   extractYear(req.ReleaseDate),
 		"disc":   req.DiscNumber,
 	})
-	filename = sanitizeFilename(filename) + ".flac"
+
-	outputPath := filepath.Join(req.OutputDir, filename)
+	var outputPath string
+	var m4aPath string
+	if quality == "HIGH" {
+		filename = sanitizeFilename(filename) + ".m4a"
+		outputPath = filepath.Join(req.OutputDir, filename)
+		m4aPath = outputPath
+	} else {
+		filename = sanitizeFilename(filename) + ".flac"
+		outputPath = filepath.Join(req.OutputDir, filename)
+		m4aPath = strings.TrimSuffix(outputPath, ".flac") + ".m4a"
+	}
 
 	if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
 		return TidalDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
-	m4aPath := strings.TrimSuffix(outputPath, ".flac") + ".m4a"
+	if quality != "HIGH" {
-	if fileInfo, statErr := os.Stat(m4aPath); statErr == nil && fileInfo.Size() > 0 {
+		if fileInfo, statErr := os.Stat(m4aPath); statErr == nil && fileInfo.Size() > 0 {
-		return TidalDownloadResult{FilePath: "EXISTS:" + m4aPath}, nil
+			return TidalDownloadResult{FilePath: "EXISTS:" + m4aPath}, nil
+		}
 	}
 
 	tmpPath := outputPath + ".m4a.tmp"
@@ -1527,10 +1543,6 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		os.Remove(tmpPath)
 	}
 
-	quality := req.Quality
-	if quality == "" {
-		quality = "LOSSLESS"
-	}
 	GoLog("[Tidal] Using quality: %s\n", quality)
 
 	downloadInfo, err := downloader.GetDownloadURL(track.ID, quality)
@@ -1593,7 +1605,6 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		GoLog("[Tidal] Using release date from Tidal API: %s\n", releaseDate)
 	}
 
-	// Use track number from request if available, otherwise from Tidal API
 	actualTrackNumber := req.TrackNumber
 	actualDiscNumber := req.DiscNumber
 	if actualTrackNumber == 0 {
@@ -1656,15 +1667,52 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 			fmt.Println("[Tidal] No lyrics available from parallel fetch")
 		}
 	} else if strings.HasSuffix(actualOutputPath, ".m4a") {
-		fmt.Println("[Tidal] Skipping metadata embedding for M4A file (will be handled after FFmpeg conversion)")
+		if quality == "HIGH" {
+			GoLog("[Tidal] HIGH quality M4A - skipping metadata embedding (file from server is already valid)\n")
+
+			if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+				lyricsMode := req.LyricsMode
+				if lyricsMode == "" {
+					lyricsMode = "embed"
+				}
+
+				if lyricsMode == "external" || lyricsMode == "both" {
+					GoLog("[Tidal] Saving external LRC file for M4A (mode: %s)...\n", lyricsMode)
+					if lrcPath, lrcErr := SaveLRCFile(actualOutputPath, parallelResult.LyricsLRC); lrcErr != nil {
+						GoLog("[Tidal] Warning: failed to save LRC file: %v\n", lrcErr)
+					} else {
+						GoLog("[Tidal] LRC file saved: %s\n", lrcPath)
+					}
+				}
+			}
+		} else {
+			fmt.Println("[Tidal] Skipping metadata embedding for M4A file (will be handled after FFmpeg conversion)")
+		}
 	}
 
 	AddToISRCIndex(req.OutputDir, req.ISRC, actualOutputPath)
 
+	bitDepth := downloadInfo.BitDepth
+	sampleRate := downloadInfo.SampleRate
+	lyricsLRC := ""
+	if quality == "HIGH" {
+		bitDepth = 0
+		sampleRate = 44100
+		if parallelResult != nil && parallelResult.LyricsLRC != "" {
+			lyricsMode := req.LyricsMode
+			if lyricsMode == "" {
+				lyricsMode = "embed"
+			}
+			if lyricsMode == "embed" || lyricsMode == "both" {
+				lyricsLRC = parallelResult.LyricsLRC
+			}
+		}
+	}
+
 	return TidalDownloadResult{
 		FilePath:    actualOutputPath,
-		BitDepth:    downloadInfo.BitDepth,
+		BitDepth:    bitDepth,
-		SampleRate:  downloadInfo.SampleRate,
+		SampleRate:  sampleRate,
 		Title:       track.Title,
 		Artist:      track.Artist.Name,
 		Album:       track.Album.Title,
@@ -1672,5 +1720,6 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		TrackNumber: actualTrackNumber,
 		DiscNumber:  actualDiscNumber,
 		ISRC:        track.ISRC,
+		LyricsLRC:   lyricsLRC,
 	}, nil
 }

lib/constants/app_info.dart

@@ -1,8 +1,8 @@
 /// App version and info constants
 /// Update version here only - all other files will reference this
 class AppInfo {
-static const String version = '3.3.1';
+static const String version = '3.3.5';
-  static const String buildNumber = '68';
+  static const String buildNumber = '70';
   static const String fullVersion = '$version+$buildNumber';
   
   

lib/l10n/app_localizations.dart

@@ -1312,6 +1312,12 @@ abstract class AppLocalizations {
   /// **'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.'**
   String get setupIosEmptyFolderWarning;
 
+  /// Error when user selects iCloud Drive on iOS
+  ///
+  /// In en, this message translates to:
+  /// **'iCloud Drive is not supported. Please use the app Documents folder.'**
+  String get setupIcloudNotSupported;
+
   /// App tagline in setup
   ///
   /// In en, this message translates to:
@@ -3646,6 +3652,42 @@ abstract class AppLocalizations {
   /// **'Are you sure you want to clear all downloads?'**
   String get queueClearAllMessage;
 
+  /// Button - export failed downloads to TXT
+  ///
+  /// In en, this message translates to:
+  /// **'Export'**
+  String get queueExportFailed;
+
+  /// Success message after exporting failed downloads
+  ///
+  /// In en, this message translates to:
+  /// **'Failed downloads exported to TXT file'**
+  String get queueExportFailedSuccess;
+
+  /// Action to clear failed downloads after export
+  ///
+  /// In en, this message translates to:
+  /// **'Clear Failed'**
+  String get queueExportFailedClear;
+
+  /// Error message when export fails
+  ///
+  /// In en, this message translates to:
+  /// **'Failed to export downloads'**
+  String get queueExportFailedError;
+
+  /// Setting toggle for auto-export
+  ///
+  /// In en, this message translates to:
+  /// **'Auto-export failed downloads'**
+  String get settingsAutoExportFailed;
+
+  /// Subtitle for auto-export setting
+  ///
+  /// In en, this message translates to:
+  /// **'Save failed downloads to TXT file automatically'**
+  String get settingsAutoExportFailedSubtitle;
+
   /// Empty queue state title
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -698,6 +698,10 @@ class AppLocalizationsDe extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS-Einschränkung: Leere Ordner können nicht ausgewählt werden. Wählen Sie einen Ordner mit mindestens einer Datei.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Spotify Titel in FLAC herunterladen';
 
@@ -2001,6 +2005,26 @@ class AppLocalizationsDe extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_en.dart

@@ -684,6 +684,10 @@ class AppLocalizationsEn extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsEn extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_es.dart

@@ -684,6 +684,10 @@ class AppLocalizationsEs extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsEs extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_fr.dart

@@ -684,6 +684,10 @@ class AppLocalizationsFr extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsFr extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_hi.dart

@@ -684,6 +684,10 @@ class AppLocalizationsHi extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsHi extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_id.dart

@@ -689,6 +689,10 @@ class AppLocalizationsId extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'Batasan iOS: Folder kosong tidak dapat dipilih. Pilih folder dengan minimal satu file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Unduh lagu Spotify dalam format FLAC';
 
@@ -1999,6 +2003,26 @@ class AppLocalizationsId extends AppLocalizations {
   String get queueClearAllMessage =>
       'Apakah Anda yakin ingin menghapus semua unduhan?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'Tidak ada unduhan dalam antrian';
 

lib/l10n/app_localizations_ja.dart

@@ -679,6 +679,10 @@ class AppLocalizationsJa extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Spotify のトラックを FLAC でダウンロード';
 
@@ -1973,6 +1977,26 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get queueClearAllMessage => 'すべてのダウンロードを消去してもよろしいですか？';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'キューにダウンロードがありません';
 

lib/l10n/app_localizations_ko.dart

@@ -684,6 +684,10 @@ class AppLocalizationsKo extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsKo extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_nl.dart

@@ -684,6 +684,10 @@ class AppLocalizationsNl extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsNl extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_pt.dart

@@ -684,6 +684,10 @@ class AppLocalizationsPt extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsPt extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_ru.dart

@@ -702,6 +702,10 @@ class AppLocalizationsRu extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'Ограничение iOS: пустые папки не могут быть выбраны. Выберите папку, содержащую хотя бы один файл.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Скачать Spotify треки во FLAC';
 
@@ -2025,6 +2029,26 @@ class AppLocalizationsRu extends AppLocalizations {
   String get queueClearAllMessage =>
       'Вы уверены, что хотите очистить все загрузки?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'Нет загрузок в очереди';
 

lib/l10n/app_localizations_tr.dart

@@ -691,6 +691,10 @@ class AppLocalizationsTr extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS\'un sınırlaması: Boş klasörler seçilemiyor. İçinde en az bir dosya bulunan bir klasör seçin.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Spotify şarkılarını FLAC olarak indirin';
 
@@ -2001,6 +2005,26 @@ class AppLocalizationsTr extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/app_localizations_zh.dart

@@ -684,6 +684,10 @@ class AppLocalizationsZh extends AppLocalizations {
   String get setupIosEmptyFolderWarning =>
       'iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.';
 
+  @override
+  String get setupIcloudNotSupported =>
+      'iCloud Drive is not supported. Please use the app Documents folder.';
+
   @override
   String get setupDownloadInFlac => 'Download Spotify tracks in FLAC';
 
@@ -1986,6 +1990,26 @@ class AppLocalizationsZh extends AppLocalizations {
   String get queueClearAllMessage =>
       'Are you sure you want to clear all downloads?';
 
+  @override
+  String get queueExportFailed => 'Export';
+
+  @override
+  String get queueExportFailedSuccess =>
+      'Failed downloads exported to TXT file';
+
+  @override
+  String get queueExportFailedClear => 'Clear Failed';
+
+  @override
+  String get queueExportFailedError => 'Failed to export downloads';
+
+  @override
+  String get settingsAutoExportFailed => 'Auto-export failed downloads';
+
+  @override
+  String get settingsAutoExportFailedSubtitle =>
+      'Save failed downloads to TXT file automatically';
+
   @override
   String get queueEmpty => 'No downloads in queue';
 

lib/l10n/arb/app_en.arb

@@ -481,8 +481,10 @@
   "@setupChooseFromFiles": {"description": "iOS file picker option"},
   "setupChooseFromFilesSubtitle": "Select iCloud or other location",
   "@setupChooseFromFilesSubtitle": {"description": "Subtitle for file picker"},
-  "setupIosEmptyFolderWarning": "iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.",
+"setupIosEmptyFolderWarning": "iOS limitation: Empty folders cannot be selected. Choose a folder with at least one file.",
   "@setupIosEmptyFolderWarning": {"description": "iOS folder selection warning"},
+  "setupIcloudNotSupported": "iCloud Drive is not supported. Please use the app Documents folder.",
+  "@setupIcloudNotSupported": {"description": "Error when user selects iCloud Drive on iOS"},
   "setupDownloadInFlac": "Download Spotify tracks in FLAC",
   "@setupDownloadInFlac": {"description": "App tagline in setup"},
   "setupStepStorage": "Storage",
@@ -1458,10 +1460,22 @@
 
   "queueTitle": "Download Queue",
   "@queueTitle": {"description": "Queue screen title"},
-  "queueClearAll": "Clear All",
+"queueClearAll": "Clear All",
   "@queueClearAll": {"description": "Button - clear all queue items"},
   "queueClearAllMessage": "Are you sure you want to clear all downloads?",
   "@queueClearAllMessage": {"description": "Clear queue confirmation"},
+  "queueExportFailed": "Export",
+  "@queueExportFailed": {"description": "Button - export failed downloads to TXT"},
+  "queueExportFailedSuccess": "Failed downloads exported to TXT file",
+  "@queueExportFailedSuccess": {"description": "Success message after exporting failed downloads"},
+  "queueExportFailedClear": "Clear Failed",
+  "@queueExportFailedClear": {"description": "Action to clear failed downloads after export"},
+  "queueExportFailedError": "Failed to export downloads",
+  "@queueExportFailedError": {"description": "Error message when export fails"},
+  "settingsAutoExportFailed": "Auto-export failed downloads",
+  "@settingsAutoExportFailed": {"description": "Setting toggle for auto-export"},
+  "settingsAutoExportFailedSubtitle": "Save failed downloads to TXT file automatically",
+  "@settingsAutoExportFailedSubtitle": {"description": "Subtitle for auto-export setting"},
   "queueEmpty": "No downloads in queue",
   "@queueEmpty": {"description": "Empty queue state title"},
   "queueEmptySubtitle": "Add tracks from the home screen",

lib/main.dart

@@ -43,7 +43,6 @@ class _EagerInitializationState extends ConsumerState<_EagerInitialization> {
   void initState() {
     super.initState();
     _initializeExtensions();
-    // Trigger history provider initialization without subscribing to updates.
     ref.read(downloadHistoryProvider);
   }
 

lib/models/settings.dart

@@ -31,11 +31,10 @@ class AppSettings {
   final String albumFolderStructure;
   final bool showExtensionStore;
   final String locale;
-  final bool enableLossyOption;
-  final String lossyFormat;
-  final String lossyBitrate; // e.g., 'mp3_320', 'mp3_256', 'mp3_192', 'mp3_128', 'opus_128', 'opus_96', 'opus_64'
   final String lyricsMode;
+  final String tidalHighFormat; // Format for Tidal HIGH quality: 'mp3_320' or 'opus_128'
   final bool useAllFilesAccess; // Android 13+ only: enable MANAGE_EXTERNAL_STORAGE
+  final bool autoExportFailedDownloads; // Auto export failed downloads to TXT file
 
   const AppSettings({
     this.defaultService = 'tidal',
@@ -65,11 +64,10 @@ class AppSettings {
     this.albumFolderStructure = 'artist_album',
     this.showExtensionStore = true,
     this.locale = 'system',
-    this.enableLossyOption = false,
-    this.lossyFormat = 'mp3',
-    this.lossyBitrate = 'mp3_320',
     this.lyricsMode = 'embed',
+    this.tidalHighFormat = 'mp3_320',
     this.useAllFilesAccess = false,
+    this.autoExportFailedDownloads = false,
   });
 
   AppSettings copyWith({
@@ -101,11 +99,10 @@ class AppSettings {
     String? albumFolderStructure,
     bool? showExtensionStore,
     String? locale,
-    bool? enableLossyOption,
-    String? lossyFormat,
-    String? lossyBitrate,
     String? lyricsMode,
+    String? tidalHighFormat,
     bool? useAllFilesAccess,
+    bool? autoExportFailedDownloads,
   }) {
     return AppSettings(
       defaultService: defaultService ?? this.defaultService,
@@ -135,11 +132,10 @@ class AppSettings {
       albumFolderStructure: albumFolderStructure ?? this.albumFolderStructure,
       showExtensionStore: showExtensionStore ?? this.showExtensionStore,
       locale: locale ?? this.locale,
-      enableLossyOption: enableLossyOption ?? this.enableLossyOption,
-      lossyFormat: lossyFormat ?? this.lossyFormat,
-      lossyBitrate: lossyBitrate ?? this.lossyBitrate,
       lyricsMode: lyricsMode ?? this.lyricsMode,
+      tidalHighFormat: tidalHighFormat ?? this.tidalHighFormat,
       useAllFilesAccess: useAllFilesAccess ?? this.useAllFilesAccess,
+      autoExportFailedDownloads: autoExportFailedDownloads ?? this.autoExportFailedDownloads,
     );
   }
 

lib/models/settings.g.dart

@@ -36,11 +36,11 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
       json['albumFolderStructure'] as String? ?? 'artist_album',
   showExtensionStore: json['showExtensionStore'] as bool? ?? true,
   locale: json['locale'] as String? ?? 'system',
-  enableLossyOption: json['enableLossyOption'] as bool? ?? false,
-  lossyFormat: json['lossyFormat'] as String? ?? 'mp3',
-  lossyBitrate: json['lossyBitrate'] as String? ?? 'mp3_320',
   lyricsMode: json['lyricsMode'] as String? ?? 'embed',
+  tidalHighFormat: json['tidalHighFormat'] as String? ?? 'mp3_320',
   useAllFilesAccess: json['useAllFilesAccess'] as bool? ?? false,
+  autoExportFailedDownloads:
+      json['autoExportFailedDownloads'] as bool? ?? false,
 );
 
 Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
@@ -72,9 +72,8 @@ Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
       'albumFolderStructure': instance.albumFolderStructure,
       'showExtensionStore': instance.showExtensionStore,
       'locale': instance.locale,
-      'enableLossyOption': instance.enableLossyOption,
-      'lossyFormat': instance.lossyFormat,
-      'lossyBitrate': instance.lossyBitrate,
       'lyricsMode': instance.lyricsMode,
+      'tidalHighFormat': instance.tidalHighFormat,
       'useAllFilesAccess': instance.useAllFilesAccess,
+      'autoExportFailedDownloads': instance.autoExportFailedDownloads,
     };

lib/providers/download_queue_provider.dart

@@ -150,15 +150,12 @@ class DownloadHistoryState {
           .map((item) => MapEntry(item.isrc!, item)),
       );
 
-  /// O(1) check if spotify_id exists
   bool isDownloaded(String spotifyId) =>
       _downloadedSpotifyIds.contains(spotifyId);
-  
+
-  /// O(1) lookup by spotify_id
   DownloadHistoryItem? getBySpotifyId(String spotifyId) =>
       _bySpotifyId[spotifyId];
-  
+
-  /// O(1) lookup by ISRC
   DownloadHistoryItem? getByIsrc(String isrc) =>
       _byIsrc[isrc];
 
@@ -177,7 +174,6 @@ class DownloadHistoryNotifier extends Notifier<DownloadHistoryState> {
     return DownloadHistoryState();
   }
 
-  /// Synchronously schedule load - ensures it runs before any UI renders
   void _loadFromDatabaseSync() {
     if (_isLoaded) return;
     _isLoaded = true;
@@ -193,7 +189,6 @@ class DownloadHistoryNotifier extends Notifier<DownloadHistoryState> {
         _historyLog.i('Migrated history from SharedPreferences to SQLite');
       }
       
-      // Migrate iOS paths if container UUID changed after app update
       if (Platform.isIOS) {
         final pathsMigrated = await _db.migrateIosContainerPaths();
         if (pathsMigrated) {
@@ -264,12 +259,10 @@ class DownloadHistoryNotifier extends Notifier<DownloadHistoryState> {
     return state.getBySpotifyId(spotifyId);
   }
   
-  /// O(1) lookup by ISRC
   DownloadHistoryItem? getByIsrc(String isrc) {
     return state.getByIsrc(isrc);
   }
   
-  /// Async version with database lookup (for cases where in-memory might be stale)
   Future<DownloadHistoryItem?> getBySpotifyIdAsync(String spotifyId) async {
     final inMemory = state.getBySpotifyId(spotifyId);
     if (inMemory != null) return inMemory;
@@ -286,7 +279,6 @@ class DownloadHistoryNotifier extends Notifier<DownloadHistoryState> {
     });
   }
   
-  /// Get database stats for debugging
   Future<int> getDatabaseCount() async {
     return await _db.getCount();
   }
@@ -722,7 +714,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       final isSingle = track.isSingle;
       final artistName = _sanitizeFolderName(albumArtist);
       
-      // New option: Singles folder inside Artist folder
       if (albumFolderStructure == 'artist_album_singles') {
         if (isSingle) {
           final singlesPath = '$baseDir${Platform.pathSeparator}$artistName${Platform.pathSeparator}Singles';
@@ -736,7 +727,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         }
       }
       
-      // Existing behavior: Separate Albums/ and Singles/ at root
       if (isSingle) {
         final singlesPath = '$baseDir${Platform.pathSeparator}Singles';
         await _ensureDirExists(singlesPath, label: 'Singles folder');
@@ -804,7 +794,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         .trim();
   }
 
-  /// Extract year from release date (format: "2005-06-13" or "2005")
   String? _extractYear(String? releaseDate) {
     if (releaseDate == null || releaseDate.isEmpty) return null;
     final match = _yearRegex.firstMatch(releaseDate);
@@ -1023,12 +1012,74 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
     }
   }
 
-  void removeItem(String id) {
+void removeItem(String id) {
     final items = state.items.where((item) => item.id != id).toList();
     state = state.copyWith(items: items);
     _saveQueueToStorage();
   }
 
+  /// Export failed downloads to a TXT file
+  /// Returns the file path if successful, null otherwise
+  Future<String?> exportFailedDownloads() async {
+    final failedItems = state.items
+        .where((item) => item.status == DownloadStatus.failed)
+        .toList();
+
+    if (failedItems.isEmpty) {
+      _log.d('No failed downloads to export');
+      return null;
+    }
+
+    try {
+      final buffer = StringBuffer();
+      buffer.writeln('# SpotiFLAC Failed Downloads');
+      buffer.writeln('# Exported: ${DateTime.now().toIso8601String()}');
+      buffer.writeln('# Total: ${failedItems.length} tracks');
+      buffer.writeln('#');
+      buffer.writeln('# Format: Track - Artist | Spotify URL | Error');
+      buffer.writeln('');
+
+      for (final item in failedItems) {
+        final track = item.track;
+        final spotifyUrl = track.id.startsWith('deezer:')
+            ? 'https://www.deezer.com/track/${track.id.substring(7)}'
+            : 'https://open.spotify.com/track/${track.id}';
+        final error = item.error ?? 'Unknown error';
+        buffer.writeln('${track.name} - ${track.artistName} | $spotifyUrl | $error');
+      }
+
+      // Save to download directory
+      String exportDir = state.outputDir;
+      if (exportDir.isEmpty) {
+        final dir = await getApplicationDocumentsDirectory();
+        exportDir = dir.path;
+      }
+
+      final timestamp = DateTime.now().toIso8601String().replaceAll(':', '-').split('.').first;
+      final fileName = 'failed_downloads_$timestamp.txt';
+      final filePath = '$exportDir/$fileName';
+
+      final file = File(filePath);
+      await file.writeAsString(buffer.toString());
+
+      _log.i('Exported ${failedItems.length} failed downloads to: $filePath');
+      return filePath;
+    } catch (e) {
+      _log.e('Failed to export failed downloads: $e');
+      return null;
+    }
+  }
+
+  /// Clear all failed downloads from queue
+  void clearFailedDownloads() {
+    final items = state.items
+        .where((item) => item.status != DownloadStatus.failed)
+        .toList();
+    state = state.copyWith(items: items);
+    _saveQueueToStorage();
+    _log.d('Cleared failed downloads from queue');
+  }
+
   Future<void> _runPostProcessingHooks(String filePath, Track track) async {
     try {
       final settings = ref.read(settingsProvider);
@@ -1075,7 +1126,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
     }
   }
 
-  /// Same logic as Go backend cover.go
   String _upgradeToMaxQualityCover(String coverUrl) {
     const spotifySize300 = 'ab67616d00001e02';
     const spotifySize640 = 'ab67616d0000b273';
@@ -1192,7 +1242,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           durationMs: durationMs,
         );
 
-        // Skip instrumental tracks (no lyrics to embed)
         if (lrcContent.isNotEmpty && lrcContent != '[instrumental:true]') {
           metadata['LYRICS'] = lrcContent;
           metadata['UNSYNCEDLYRICS'] = lrcContent;
@@ -1323,7 +1372,11 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
 
       _log.d('MP3 Metadata map content: $metadata');
 
-      if (settings.embedLyrics) {
+      final lyricsMode = settings.lyricsMode;
+      final shouldEmbed = lyricsMode == 'embed' || lyricsMode == 'both';
+      final shouldSaveExternal = lyricsMode == 'external' || lyricsMode == 'both';
+      
+      if (settings.embedLyrics && (shouldEmbed || shouldSaveExternal)) {
         try {
           final durationMs = track.duration * 1000;
           
@@ -1336,12 +1389,24 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           );
 
           if (lrcContent.isNotEmpty) {
-            metadata['LYRICS'] = lrcContent;
+            if (shouldEmbed) {
-            metadata['UNSYNCEDLYRICS'] = lrcContent;
+              metadata['LYRICS'] = lrcContent;
-            _log.d('Lyrics fetched for MP3 embedding (${lrcContent.length} chars)');
+              metadata['UNSYNCEDLYRICS'] = lrcContent;
+              _log.d('Lyrics fetched for MP3 embedding (${lrcContent.length} chars)');
+            }
+            
+            if (shouldSaveExternal) {
+              try {
+                final lrcPath = mp3Path.replaceAll(RegExp(r'\.mp3$', caseSensitive: false), '.lrc');
+                await File(lrcPath).writeAsString(lrcContent);
+                _log.d('External LRC file saved: $lrcPath');
+              } catch (e) {
+                _log.w('Failed to save external LRC file: $e');
+              }
+            }
           }
         } catch (e) {
-          _log.w('Failed to fetch lyrics for MP3 embedding: $e');
+          _log.w('Failed to fetch lyrics for MP3: $e');
         }
       }
 
@@ -1461,7 +1526,12 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
 
       _log.d('Opus Metadata map content: $metadata');
 
-      if (settings.embedLyrics) {
+      // Handle lyrics based on lyricsMode setting
+      final lyricsMode = settings.lyricsMode;
+      final shouldEmbed = lyricsMode == 'embed' || lyricsMode == 'both';
+      final shouldSaveExternal = lyricsMode == 'external' || lyricsMode == 'both';
+      
+      if (settings.embedLyrics && (shouldEmbed || shouldSaveExternal)) {
         try {
           final durationMs = track.duration * 1000;
           
@@ -1474,11 +1544,25 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           );
 
           if (lrcContent.isNotEmpty) {
-            metadata['LYRICS'] = lrcContent;
+            // Embed lyrics in file metadata if mode is 'embed' or 'both'
-            _log.d('Lyrics fetched for Opus embedding (${lrcContent.length} chars)');
+            if (shouldEmbed) {
+              metadata['LYRICS'] = lrcContent;
+              _log.d('Lyrics fetched for Opus embedding (${lrcContent.length} chars)');
+            }
+            
+            // Save external LRC file if mode is 'external' or 'both'
+            if (shouldSaveExternal) {
+              try {
+                final lrcPath = opusPath.replaceAll(RegExp(r'\.opus$', caseSensitive: false), '.lrc');
+                await File(lrcPath).writeAsString(lrcContent);
+                _log.d('External LRC file saved: $lrcPath');
+              } catch (e) {
+                _log.w('Failed to save external LRC file: $e');
+              }
+            }
           }
         } catch (e) {
-          _log.w('Failed to fetch lyrics for Opus embedding: $e');
+          _log.w('Failed to fetch lyrics for Opus: $e');
         }
       }
 
@@ -1542,11 +1626,28 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       }
     }
 
-    if (state.outputDir.isEmpty) {
+if (state.outputDir.isEmpty) {
       _log.d('Output dir empty, initializing...');
       await _initOutputDir();
     }
 
+    // iOS: Validate that outputDir is writable (not iCloud Drive which Go can't access)
+    if (Platform.isIOS && state.outputDir.isNotEmpty) {
+      final isICloudPath = state.outputDir.contains('Mobile Documents') ||
+          state.outputDir.contains('CloudDocs') ||
+          state.outputDir.contains('com~apple~CloudDocs');
+      if (isICloudPath) {
+        _log.w('iOS: iCloud Drive path detected, falling back to app Documents folder');
+        _log.w('Go backend cannot write to iCloud Drive due to iOS sandboxing');
+        final dir = await getApplicationDocumentsDirectory();
+        final musicDir = Directory('${dir.path}/SpotiFLAC');
+        if (!await musicDir.exists()) {
+          await musicDir.create(recursive: true);
+        }
+        state = state.copyWith(outputDir: musicDir.path);
+      }
+    }
+
     if (state.outputDir.isEmpty) {
       _log.d('Using fallback directory...');
       final dir = await getApplicationDocumentsDirectory();
@@ -1587,7 +1688,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       _downloadCount = 0;
     }
 
-    _log.i(
+_log.i(
       'Queue stats - completed: $_completedInSession, failed: $_failedInSession, totalAtStart: $_totalQueuedAtStart',
     );
     if (_totalQueuedAtStart > 0) {
@@ -1595,6 +1696,15 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         completedCount: _completedInSession,
         failedCount: _failedInSession,
       );
+
+      // Auto-export failed downloads if enabled
+      final settings = ref.read(settingsProvider);
+      if (settings.autoExportFailedDownloads && _failedInSession > 0) {
+        final exportPath = await exportFailedDownloads();
+        if (exportPath != null) {
+          _log.i('Auto-exported failed downloads to: $exportPath');
+        }
+      }
     }
 
     _log.i('Queue processing finished');
@@ -1804,12 +1914,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       );
 
       final quality = item.qualityOverride ?? state.audioQuality;
-      
-      // For LOSSY, we need to download FLAC first then convert
-      // Servers don't support lossy quality directly
-      final downloadQuality = quality == 'LOSSY' ? 'LOSSLESS' : quality;
 
-// Fetch extended metadata (genre, label) from Deezer if available
       String? genre;
       String? label;
       
@@ -1858,10 +1963,10 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       if (useExtensions) {
         _log.d('Using extension providers for download');
         _log.d(
-          'Quality: $quality${item.qualityOverride != null ? ' (override)' : ''}${quality == 'LOSSY' ? ' (downloading as LOSSLESS for conversion)' : ''}',
+          'Quality: $quality${item.qualityOverride != null ? ' (override)' : ''}',
         );
         _log.d('Output dir: $outputDir');
-        result = await PlatformBridge.downloadWithExtensions(
+result = await PlatformBridge.downloadWithExtensions(
           isrc: trackToDownload.isrc ?? '',
           spotifyId: trackToDownload.id,
           trackName: trackToDownload.name,
@@ -1871,7 +1976,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           coverUrl: trackToDownload.coverUrl,
           outputDir: outputDir,
           filenameFormat: state.filenameFormat,
-          quality: downloadQuality,
+          quality: quality,
           trackNumber: trackToDownload.trackNumber ?? 1,
           discNumber: trackToDownload.discNumber ?? 1,
           releaseDate: trackToDownload.releaseDate,
@@ -1881,11 +1986,12 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           genre: genre,
           label: label,
           lyricsMode: settings.lyricsMode,
+          preferredService: item.service,
         );
       } else if (state.autoFallback) {
         _log.d('Using auto-fallback mode');
         _log.d(
-          'Quality: $quality${item.qualityOverride != null ? ' (override)' : ''}${quality == 'LOSSY' ? ' (downloading as LOSSLESS for conversion)' : ''}',
+          'Quality: $quality${item.qualityOverride != null ? ' (override)' : ''}',
         );
         _log.d('Output dir: $outputDir');
         result = await PlatformBridge.downloadWithFallback(
@@ -1898,7 +2004,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           coverUrl: trackToDownload.coverUrl,
           outputDir: outputDir,
           filenameFormat: state.filenameFormat,
-          quality: downloadQuality,
+          quality: quality,
           trackNumber: trackToDownload.trackNumber ?? 1,
           discNumber: trackToDownload.discNumber ?? 1,
           releaseDate: trackToDownload.releaseDate,
@@ -1921,7 +2027,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           coverUrl: trackToDownload.coverUrl,
           outputDir: outputDir,
           filenameFormat: state.filenameFormat,
-          quality: downloadQuality,
+          quality: quality,
           trackNumber: trackToDownload.trackNumber ?? 1,
           discNumber: trackToDownload.discNumber ?? 1,
           releaseDate: trackToDownload.releaseDate,
@@ -1980,9 +2086,77 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         }
 
         if (filePath != null && filePath.endsWith('.m4a')) {
-          _log.d(
+          // For HIGH quality (Tidal AAC 320kbps), convert to MP3 or Opus
-            'M4A file detected (Hi-Res DASH stream), attempting conversion to FLAC...',
+          if (quality == 'HIGH') {
-          );
+            final tidalHighFormat = settings.tidalHighFormat;
+            _log.i('Tidal HIGH quality download, converting M4A to $tidalHighFormat...');
+            
+            try {
+              updateItemStatus(
+                item.id,
+                DownloadStatus.downloading,
+                progress: 0.95,
+              );
+              
+              // Convert M4A to the selected format
+              final format = tidalHighFormat.startsWith('opus') ? 'opus' : 'mp3';
+              final convertedPath = await FFmpegService.convertM4aToLossy(
+                filePath,
+                format: format,
+                bitrate: tidalHighFormat,
+                deleteOriginal: true,
+              );
+              
+              if (convertedPath != null) {
+                filePath = convertedPath;
+                final bitrateDisplay = tidalHighFormat.contains('_') 
+                    ? '${tidalHighFormat.split('_').last}kbps' 
+                    : '320kbps';
+                actualQuality = '${format.toUpperCase()} $bitrateDisplay';
+                _log.i('Successfully converted M4A to $format: $convertedPath');
+                
+                // Embed metadata
+                _log.i('Embedding metadata to $format...');
+                updateItemStatus(
+                  item.id,
+                  DownloadStatus.downloading,
+                  progress: 0.99,
+                );
+                
+                final backendGenre = result['genre'] as String?;
+                final backendLabel = result['label'] as String?;
+                final backendCopyright = result['copyright'] as String?;
+                
+                if (format == 'mp3') {
+                  await _embedMetadataToMp3(
+                    convertedPath, 
+                    trackToDownload,
+                    genre: backendGenre ?? genre,
+                    label: backendLabel ?? label,
+                    copyright: backendCopyright,
+                  );
+                } else {
+                  await _embedMetadataToOpus(
+                    convertedPath, 
+                    trackToDownload,
+                    genre: backendGenre ?? genre,
+                    label: backendLabel ?? label,
+                    copyright: backendCopyright,
+                  );
+                }
+                _log.d('Metadata embedded successfully');
+              } else {
+                _log.w('M4A to $format conversion failed, keeping M4A file');
+                actualQuality = 'AAC 320kbps';
+              }
+            } catch (e) {
+              _log.w('M4A conversion process failed: $e, keeping M4A file');
+              actualQuality = 'AAC 320kbps';
+            }
+          } else {
+            _log.d(
+              'M4A file detected (Hi-Res DASH stream), attempting conversion to FLAC...',
+            );
 
           try {
             final file = File(filePath);
@@ -2084,6 +2258,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           } catch (e) {
             _log.w('FFmpeg conversion process failed: $e, keeping M4A file');
           }
+          }
         }
 
         final itemAfterDownload = state.items.firstWhere(
@@ -2106,74 +2281,6 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           return;
         }
 
-        if (quality == 'LOSSY' && filePath != null && filePath.endsWith('.flac')) {
-          if (wasExisting) {
-            _log.i('Lossy requested but existing FLAC found - skipping conversion to preserve original file');
-          } else {
-            final lossyFormat = settings.lossyFormat;
-            final lossyBitrate = settings.lossyBitrate;
-            _log.i('Lossy quality selected, converting FLAC to $lossyFormat ($lossyBitrate)...');
-            updateItemStatus(
-              item.id,
-              DownloadStatus.downloading,
-              progress: 0.97,
-            );
-            
-            try {
-              final convertedPath = await FFmpegService.convertFlacToLossy(
-                filePath,
-                format: lossyFormat,
-                bitrate: lossyBitrate,
-                deleteOriginal: true,
-              );
-              
-              if (convertedPath != null) {
-                filePath = convertedPath;
-                // Extract bitrate for display (e.g., 'mp3_320' -> '320kbps')
-                final bitrateDisplay = lossyBitrate.contains('_') 
-                    ? '${lossyBitrate.split('_').last}kbps' 
-                    : (lossyFormat == 'opus' ? '128kbps' : '320kbps');
-                actualQuality = '${lossyFormat.toUpperCase()} $bitrateDisplay';
-                _log.i('Successfully converted to $lossyFormat ($bitrateDisplay): $convertedPath');
-                
-                // Embed metadata and cover for both MP3 and Opus
-                _log.i('Embedding metadata to $lossyFormat...');
-                updateItemStatus(
-                  item.id,
-                  DownloadStatus.downloading,
-                  progress: 0.99,
-                );
-                
-                final lossyBackendGenre = result['genre'] as String?;
-                final lossyBackendLabel = result['label'] as String?;
-                final lossyBackendCopyright = result['copyright'] as String?;
-                
-                if (lossyFormat == 'mp3') {
-                  await _embedMetadataToMp3(
-                    convertedPath, 
-                    trackToDownload,
-                    genre: lossyBackendGenre ?? genre,
-                    label: lossyBackendLabel ?? label,
-                    copyright: lossyBackendCopyright,
-                  );
-                } else if (lossyFormat == 'opus') {
-                  await _embedMetadataToOpus(
-                    convertedPath, 
-                    trackToDownload,
-                    genre: lossyBackendGenre ?? genre,
-                    label: lossyBackendLabel ?? label,
-                    copyright: lossyBackendCopyright,
-                  );
-                }
-              } else {
-                _log.w('$lossyFormat conversion failed, keeping FLAC file');
-              }
-            } catch (e) {
-              _log.e('Lossy conversion error: $e, keeping FLAC file');
-            }
-          }
-        }
-
         updateItemStatus(
           item.id,
           DownloadStatus.completed,

lib/providers/settings_provider.dart

@@ -231,31 +231,20 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
-  void setEnableLossyOption(bool enabled) {
+  void setTidalHighFormat(String format) {
-    state = state.copyWith(enableLossyOption: enabled);
+    state = state.copyWith(tidalHighFormat: format);
-    // If Lossy is disabled and current quality is LOSSY, reset to LOSSLESS
-    if (!enabled && state.audioQuality == 'LOSSY') {
-      state = state.copyWith(audioQuality: 'LOSSLESS');
-    }
     _saveSettings();
   }
 
-  void setLossyFormat(String format) {
+void setUseAllFilesAccess(bool enabled) {
-    state = state.copyWith(lossyFormat: format);
-    _saveSettings();
-  }
-
-  void setLossyBitrate(String bitrate) {
-    // Extract format from bitrate (e.g., 'mp3_320' -> 'mp3')
-    final format = bitrate.split('_').first;
-    state = state.copyWith(lossyBitrate: bitrate, lossyFormat: format);
-    _saveSettings();
-  }
-
-  void setUseAllFilesAccess(bool enabled) {
     state = state.copyWith(useAllFilesAccess: enabled);
     _saveSettings();
   }
+
+  void setAutoExportFailedDownloads(bool enabled) {
+    state = state.copyWith(autoExportFailedDownloads: enabled);
+    _saveSettings();
+  }
 }
 
 final settingsProvider = NotifierProvider<SettingsNotifier, AppSettings>(

lib/screens/album_screen.dart

@@ -80,7 +80,9 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen> {
     _scrollController.addListener(_onScroll);
     
     WidgetsBinding.instance.addPostFrameCallback((_) {
-      final providerId = widget.albumId.startsWith('deezer:') ? 'deezer' : 'spotify';
+      // Use extensionId if available, otherwise detect from albumId prefix
+      final providerId = widget.extensionId ?? 
+          (widget.albumId.startsWith('deezer:') ? 'deezer' : 'spotify');
       ref.read(recentAccessProvider.notifier).recordAlbumAccess(
         id: widget.albumId,
         name: widget.albumName,
@@ -90,10 +92,15 @@ class _AlbumScreenState extends ConsumerState<AlbumScreen> {
 );
     });
     
-    _tracks = widget.tracks ?? _AlbumCache.get(widget.albumId);
+    // Use provided tracks if not empty, otherwise try cache
+    if (widget.tracks != null && widget.tracks!.isNotEmpty) {
+      _tracks = widget.tracks;
+    } else {
+      _tracks = _AlbumCache.get(widget.albumId);
+    }
     _artistId = widget.artistId; // Use provided artist ID if available
     
-    if (_tracks == null) {
+    if (_tracks == null || _tracks!.isEmpty) {
       _fetchTracks();
     }
     

lib/screens/home_tab.dart

@@ -1887,12 +1887,6 @@ class _HomeTabState extends ConsumerState<HomeTab> with AutomaticKeepAliveClient
   void _navigateToSearchAlbum(SearchAlbum album) {
     ref.read(settingsProvider.notifier).setHasSearchedBefore();
     
-    // Extract the numeric ID from "deezer:123" format
-    String albumId = album.id;
-    if (albumId.startsWith('deezer:')) {
-      albumId = albumId.substring(7);
-    }
-    
     ref.read(recentAccessProvider.notifier).recordAlbumAccess(
       id: album.id,
       name: album.name,
@@ -1901,9 +1895,10 @@ class _HomeTabState extends ConsumerState<HomeTab> with AutomaticKeepAliveClient
       providerId: 'deezer',
     );
     
+    // Keep the full ID with prefix (e.g., "deezer:123") for AlbumScreen to detect source
     Navigator.push(context, MaterialPageRoute(
       builder: (context) => AlbumScreen(
-        albumId: albumId,
+        albumId: album.id,
         albumName: album.name,
         coverUrl: album.imageUrl,
         tracks: const [], // Will be fetched by AlbumScreen
@@ -1914,12 +1909,6 @@ class _HomeTabState extends ConsumerState<HomeTab> with AutomaticKeepAliveClient
   void _navigateToSearchPlaylist(SearchPlaylist playlist) {
     ref.read(settingsProvider.notifier).setHasSearchedBefore();
     
-    // Extract the numeric ID from "deezer:123" format
-    String playlistId = playlist.id;
-    if (playlistId.startsWith('deezer:')) {
-      playlistId = playlistId.substring(7);
-    }
-    
     ref.read(recentAccessProvider.notifier).recordPlaylistAccess(
       id: playlist.id,
       name: playlist.name,
@@ -1928,12 +1917,13 @@ class _HomeTabState extends ConsumerState<HomeTab> with AutomaticKeepAliveClient
       providerId: 'deezer',
     );
     
+    // Keep the full ID with prefix (e.g., "deezer:123") for PlaylistScreen to detect source
     Navigator.push(context, MaterialPageRoute(
       builder: (context) => PlaylistScreen(
         playlistName: playlist.name,
         coverUrl: playlist.imageUrl,
         tracks: const [], // Will be fetched
-        playlistId: playlistId,
+        playlistId: playlist.id,
       ),
     ));
   }

lib/screens/playlist_screen.dart

@@ -64,10 +64,17 @@ class _PlaylistScreenState extends ConsumerState<PlaylistScreen> {
     });
     
     try {
-      final result = await PlatformBridge.getDeezerMetadata('playlist', widget.playlistId!);
+      // Extract numeric ID from "deezer:123" format
+      String playlistId = widget.playlistId!;
+      if (playlistId.startsWith('deezer:')) {
+        playlistId = playlistId.substring(7);
+      }
+      
+      final result = await PlatformBridge.getDeezerMetadata('playlist', playlistId);
       if (!mounted) return;
       
-      final trackList = result['tracks'] as List<dynamic>? ?? [];
+      // Go backend returns 'track_list' not 'tracks'
+      final trackList = result['track_list'] as List<dynamic>? ?? [];
       final tracks = trackList.map((t) => _parseTrack(t as Map<String, dynamic>)).toList();
       
       setState(() {

lib/screens/queue_tab.dart

@@ -806,7 +806,9 @@ final queueItems = ref.watch(downloadQueueProvider.select((s) => s.items));
                             fontWeight: FontWeight.bold,
                           ),
                         ),
-                        const Spacer(),
+const Spacer(),
+                        _buildExportFailedButton(context, ref, colorScheme),
+                        const SizedBox(width: 4),
                         _buildPauseResumeButton(context, ref, colorScheme),
                         const SizedBox(width: 4),
                         _buildClearAllButton(context, ref, colorScheme),
@@ -1194,7 +1196,7 @@ if (queueItems.isEmpty &&
     );
   }
 
-  Widget _buildClearAllButton(
+Widget _buildClearAllButton(
     BuildContext context,
     WidgetRef ref,
     ColorScheme colorScheme,
@@ -1210,6 +1212,60 @@ if (queueItems.isEmpty &&
     );
   }
 
+  Widget _buildExportFailedButton(
+    BuildContext context,
+    WidgetRef ref,
+    ColorScheme colorScheme,
+  ) {
+    final queueState = ref.watch(downloadQueueProvider);
+    final failedCount = queueState.failedCount;
+
+    if (failedCount == 0) {
+      return const SizedBox.shrink();
+    }
+
+    return TextButton.icon(
+      onPressed: () => _exportFailedDownloads(context, ref),
+      icon: const Icon(Icons.file_download, size: 18),
+      label: Text(context.l10n.queueExportFailed),
+      style: TextButton.styleFrom(
+        visualDensity: VisualDensity.compact,
+        foregroundColor: colorScheme.tertiary,
+      ),
+    );
+  }
+
+  Future<void> _exportFailedDownloads(
+    BuildContext context,
+    WidgetRef ref,
+  ) async {
+    final filePath = await ref.read(downloadQueueProvider.notifier).exportFailedDownloads();
+    
+    if (!context.mounted) return;
+    
+    if (filePath != null) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text(context.l10n.queueExportFailedSuccess),
+          action: SnackBarAction(
+            label: context.l10n.queueExportFailedClear,
+            onPressed: () {
+              ref.read(downloadQueueProvider.notifier).clearFailedDownloads();
+            },
+          ),
+          duration: const Duration(seconds: 5),
+        ),
+      );
+    } else {
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text(context.l10n.queueExportFailedError),
+          backgroundColor: Theme.of(context).colorScheme.error,
+        ),
+      );
+    }
+  }
+
   Future<void> _showClearAllDialog(
     BuildContext context,
     WidgetRef ref,

lib/screens/settings/download_settings_page.dart

@@ -94,6 +94,7 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
     final topPadding = MediaQuery.of(context).padding.top;
     
     final isBuiltInService = _builtInServices.contains(settings.defaultService);
+    final isTidalService = settings.defaultService == 'tidal';
 
     return PopScope(
       canPop: true,
@@ -173,24 +174,6 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                         .read(settingsProvider.notifier)
                         .setAskQualityBeforeDownload(value),
                   ),
-                  SettingsSwitchItem(
-                    icon: Icons.audiotrack,
-                    title: context.l10n.enableLossyOption,
-                    subtitle: settings.enableLossyOption
-                        ? context.l10n.enableLossyOptionSubtitleOn
-                        : context.l10n.enableLossyOptionSubtitleOff,
-                    value: settings.enableLossyOption,
-                    onChanged: (value) => ref
-                        .read(settingsProvider.notifier)
-                        .setEnableLossyOption(value),
-                  ),
-                  if (settings.enableLossyOption)
-                    SettingsItem(
-                      icon: Icons.tune,
-                      title: context.l10n.lossyFormat,
-                      subtitle: _getLossyBitrateLabel(settings.lossyBitrate),
-                      onTap: () => _showLossyBitratePicker(context, ref, settings.lossyBitrate),
-                    ),
                   if (!settings.askQualityBeforeDownload && isBuiltInService) ...[
                     _QualityOption(
                       title: context.l10n.qualityFlacLossless,
@@ -215,18 +198,25 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                       onTap: () => ref
                           .read(settingsProvider.notifier)
                           .setAudioQuality('HI_RES_LOSSLESS'),
-                      showDivider: settings.enableLossyOption,
+                      showDivider: isTidalService,
                     ),
-                    if (settings.enableLossyOption)
+                    // Lossy 320kbps option (Tidal only) - downloads M4A, converts to MP3/Opus
+                    if (isTidalService)
                       _QualityOption(
-                        title: context.l10n.qualityLossy,
+                        title: 'Lossy 320kbps',
-                        subtitle: settings.lossyFormat == 'opus' 
+                        subtitle: _getTidalHighFormatLabel(settings.tidalHighFormat),
-                            ? context.l10n.qualityLossyOpusSubtitle
+                        isSelected: settings.audioQuality == 'HIGH',
-                            : context.l10n.qualityLossyMp3Subtitle,
-                        isSelected: settings.audioQuality == 'LOSSY',
                         onTap: () => ref
                             .read(settingsProvider.notifier)
-                            .setAudioQuality('LOSSY'),
+                            .setAudioQuality('HIGH'),
+                        showDivider: false,
+                      ),
+                    if (isTidalService && settings.audioQuality == 'HIGH')
+                      SettingsItem(
+                        icon: Icons.tune,
+                        title: 'Lossy Format',
+                        subtitle: _getTidalHighFormatLabel(settings.tidalHighFormat),
+                        onTap: () => _showTidalHighFormatPicker(context, ref, settings.tidalHighFormat),
                         showDivider: false,
                       ),
                   ],
@@ -395,7 +385,27 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                   ),
                 ),
               ),
-            ],
+],
+
+            const SliverToBoxAdapter(child: SizedBox(height: 16)),
+            
+            // Auto Export Failed Downloads
+            SliverToBoxAdapter(
+              child: SettingsGroup(
+                children: [
+                  SettingsSwitchItem(
+                    icon: Icons.file_download_outlined,
+                    title: context.l10n.settingsAutoExportFailed,
+                    subtitle: context.l10n.settingsAutoExportFailedSubtitle,
+                    value: settings.autoExportFailedDownloads,
+                    onChanged: (value) {
+                      ref.read(settingsProvider.notifier).setAutoExportFailedDownloads(value);
+                    },
+                    showDivider: false,
+                  ),
+                ],
+              ),
+            ),
 
             const SliverToBoxAdapter(child: SizedBox(height: 32)),
           ],
@@ -712,7 +722,7 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                 if (ctx.mounted) Navigator.pop(ctx);
               },
             ),
-            ListTile(
+ListTile(
               leading: Icon(Icons.cloud, color: colorScheme.onSurfaceVariant),
               title: Text(context.l10n.setupChooseFromFiles),
               subtitle: Text(context.l10n.setupChooseFromFilesSubtitle),
@@ -721,6 +731,24 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                 // Note: iOS requires folder to have at least one file to be selectable
                 final result = await FilePicker.platform.getDirectoryPath();
                 if (result != null) {
+                  // iOS: Check if user selected iCloud Drive (not accessible by Go backend)
+                  if (Platform.isIOS) {
+                    final isICloudPath = result.contains('Mobile Documents') ||
+                        result.contains('CloudDocs') ||
+                        result.contains('com~apple~CloudDocs');
+                    if (isICloudPath) {
+                      if (ctx.mounted) {
+                        ScaffoldMessenger.of(ctx).showSnackBar(
+                          SnackBar(
+                            content: Text(context.l10n.setupIcloudNotSupported),
+                            backgroundColor: Theme.of(ctx).colorScheme.error,
+                            duration: const Duration(seconds: 4),
+                          ),
+                        );
+                      }
+                      return;
+                    }
+                  }
                   ref
                       .read(settingsProvider.notifier)
                       .setDownloadDirectory(result);
@@ -858,28 +886,18 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
     );
   }
 
-  String _getLossyBitrateLabel(String bitrate) {
+  String _getTidalHighFormatLabel(String format) {
-    switch (bitrate) {
+    switch (format) {
       case 'mp3_320':
-        return 'MP3 320kbps (Best)';
+        return 'MP3 320kbps';
-      case 'mp3_256':
-        return 'MP3 256kbps';
-      case 'mp3_192':
-        return 'MP3 192kbps';
-      case 'mp3_128':
-        return 'MP3 128kbps';
       case 'opus_128':
-        return 'Opus 128kbps (Best)';
+        return 'Opus 128kbps';
-      case 'opus_96':
-        return 'Opus 96kbps';
-      case 'opus_64':
-        return 'Opus 64kbps';
       default:
         return 'MP3 320kbps';
     }
   }
 
-  void _showLossyBitratePicker(
+  void _showTidalHighFormatPicker(
     BuildContext context,
     WidgetRef ref,
     String current,
@@ -888,130 +906,54 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
     showModalBottomSheet(
       context: context,
       backgroundColor: colorScheme.surfaceContainerHigh,
-      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
       ),
       builder: (context) => SafeArea(
-        child: SingleChildScrollView(
+        child: Column(
-          child: Column(
+          mainAxisSize: MainAxisSize.min,
-            mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
-            crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
-            children: [
+            Padding(
-              Padding(
+              padding: const EdgeInsets.fromLTRB(24, 24, 24, 8),
-                padding: const EdgeInsets.fromLTRB(24, 24, 24, 8),
+              child: Text(
-                child: Text(
+                'Lossy 320kbps Format',
-                  context.l10n.lossyFormat,
+                style: Theme.of(
-                  style: Theme.of(
+                  context,
-                    context,
+                ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
-                  ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(24, 0, 24, 16),
+              child: Text(
+                'Choose the output format for Tidal 320kbps lossy downloads. The original AAC stream will be converted to your selected format.',
+                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                  color: colorScheme.onSurfaceVariant,
                 ),
               ),
-              Padding(
+            ),
-                padding: const EdgeInsets.fromLTRB(24, 0, 24, 16),
+            ListTile(
-                child: Text(
+              leading: const Icon(Icons.audiotrack),
-                  context.l10n.lossyFormatDescription,
+              title: const Text('MP3 320kbps'),
-                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+              subtitle: const Text('Best compatibility, ~10MB per track'),
-                    color: colorScheme.onSurfaceVariant,
+              trailing: current == 'mp3_320' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                  ),
+              onTap: () {
-                ),
+                ref.read(settingsProvider.notifier).setTidalHighFormat('mp3_320');
-              ),
+                Navigator.pop(context);
-              // MP3 Section
+              },
-              Padding(
+            ),
-                padding: const EdgeInsets.fromLTRB(24, 8, 24, 4),
+            ListTile(
-                child: Text(
+              leading: const Icon(Icons.graphic_eq),
-                  'MP3',
+              title: const Text('Opus 128kbps'),
-                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
+              subtitle: const Text('Modern codec, ~4MB per track'),
-                    color: colorScheme.primary,
+              trailing: current == 'opus_128' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                    fontWeight: FontWeight.bold,
+              onTap: () {
-                  ),
+                ref.read(settingsProvider.notifier).setTidalHighFormat('opus_128');
-                ),
+                Navigator.pop(context);
-              ),
+              },
-              ListTile(
+            ),
-                leading: const Icon(Icons.audiotrack),
+            const SizedBox(height: 16),
-                title: const Text('320kbps'),
+          ],
-                subtitle: const Text('Best quality, larger files'),
-                trailing: current == 'mp3_320' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('mp3_320');
-                  Navigator.pop(context);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.audiotrack),
-                title: const Text('256kbps'),
-                subtitle: const Text('High quality'),
-                trailing: current == 'mp3_256' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('mp3_256');
-                  Navigator.pop(context);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.audiotrack),
-                title: const Text('192kbps'),
-                subtitle: const Text('Good quality'),
-                trailing: current == 'mp3_192' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('mp3_192');
-                  Navigator.pop(context);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.audiotrack),
-                title: const Text('128kbps'),
-                subtitle: const Text('Smaller files'),
-                trailing: current == 'mp3_128' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('mp3_128');
-                  Navigator.pop(context);
-                },
-              ),
-              const Divider(indent: 24, endIndent: 24),
-              // Opus Section
-              Padding(
-                padding: const EdgeInsets.fromLTRB(24, 8, 24, 4),
-                child: Text(
-                  'Opus',
-                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
-                    color: colorScheme.primary,
-                    fontWeight: FontWeight.bold,
-                  ),
-                ),
-              ),
-              ListTile(
-                leading: const Icon(Icons.graphic_eq),
-                title: const Text('128kbps'),
-                subtitle: const Text('Best quality, efficient codec'),
-                trailing: current == 'opus_128' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('opus_128');
-                  Navigator.pop(context);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.graphic_eq),
-                title: const Text('96kbps'),
-                subtitle: const Text('Good quality'),
-                trailing: current == 'opus_96' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('opus_96');
-                  Navigator.pop(context);
-                },
-              ),
-              ListTile(
-                leading: const Icon(Icons.graphic_eq),
-                title: const Text('64kbps'),
-                subtitle: const Text('Smallest files'),
-                trailing: current == 'opus_64' ? Icon(Icons.check, color: colorScheme.primary) : null,
-                onTap: () {
-                  ref.read(settingsProvider.notifier).setLossyBitrate('opus_64');
-                  Navigator.pop(context);
-                },
-              ),
-              const SizedBox(height: 16),
-            ],
-          ),
         ),
       ),
     );

lib/services/ffmpeg_service.dart

@@ -9,8 +9,6 @@ import 'package:spotiflac_android/utils/logger.dart';
 
 final _log = AppLogger('FFmpeg');
 
-/// FFmpeg service for audio conversion and remuxing
-/// Uses ffmpeg_kit_flutter_new_audio plugin
 class FFmpegService {
   static Future<FFmpegResult> _execute(String command) async {
     try {
@@ -48,6 +46,47 @@ class FFmpegService {
     return null;
   }
 
+  static Future<String?> convertM4aToLossy(
+    String inputPath, {
+    required String format,
+    String? bitrate,
+    bool deleteOriginal = true,
+  }) async {
+    String bitrateValue = format == 'opus' ? '128k' : '320k';
+    if (bitrate != null && bitrate.contains('_')) {
+      final parts = bitrate.split('_');
+      if (parts.length == 2) {
+        bitrateValue = '${parts[1]}k';
+      }
+    }
+    
+    final extension = format == 'opus' ? '.opus' : '.mp3';
+    final outputPath = inputPath.replaceAll('.m4a', extension);
+    
+    String command;
+    if (format == 'opus') {
+      command =
+          '-i "$inputPath" -codec:a libopus -b:a $bitrateValue -vbr on -compression_level 10 -map 0:a "$outputPath" -y';
+    } else {
+      command =
+          '-i "$inputPath" -codec:a libmp3lame -b:a $bitrateValue -map 0:a -id3v2_version 3 "$outputPath" -y';
+    }
+
+    final result = await _execute(command);
+
+    if (result.success) {
+      if (deleteOriginal) {
+        try {
+          await File(inputPath).delete();
+        } catch (_) {}
+      }
+      return outputPath;
+    }
+
+    _log.e('M4A to $format conversion failed: ${result.output}');
+    return null;
+  }
+
   static Future<String?> convertFlacToMp3(
     String inputPath, {
     String bitrate = '320k',
@@ -80,7 +119,6 @@ class FFmpegService {
   }) async {
     final outputPath = inputPath.replaceAll('.flac', '.opus');
 
-    // Opus in OGG container with VBR
     final command =
         '-i "$inputPath" -codec:a libopus -b:a $bitrate -vbr on -compression_level 10 -map 0:a -map_metadata 0 "$outputPath" -y';
 
@@ -99,17 +137,13 @@ class FFmpegService {
     return null;
   }
 
-  /// Convert FLAC to lossy format based on format parameter
-  /// format: 'mp3' or 'opus'
-  /// bitrate: e.g., 'mp3_320', 'opus_128' - extracts the kbps value
   static Future<String?> convertFlacToLossy(
     String inputPath, {
     required String format,
     String? bitrate,
     bool deleteOriginal = true,
   }) async {
-    // Extract bitrate value from format like 'mp3_320' -> '320k'
+    String bitrateValue = '320k';
-    String bitrateValue = '320k'; // default for mp3
     if (bitrate != null && bitrate.contains('_')) {
       final parts = bitrate.split('_');
       if (parts.length == 2) {
@@ -338,8 +372,6 @@ class FFmpegService {
     return null;
   }
 
-  /// Embed metadata to Opus file
-  /// Uses METADATA_BLOCK_PICTURE tag for cover art (OGG/Vorbis standard)
   static Future<String?> embedMetadataToOpus({
     required String opusPath,
     String? coverPath,
@@ -354,7 +386,6 @@ class FFmpegService {
     cmdBuffer.write('-map 0:a ');
     cmdBuffer.write('-c:a copy ');
     
-    // Embed metadata tags (Vorbis comments)
     if (metadata != null) {
       metadata.forEach((key, value) {
         final sanitizedValue = value.replaceAll('"', '\\"');
@@ -362,12 +393,10 @@ class FFmpegService {
       });
     }
     
-    // Embed cover art using METADATA_BLOCK_PICTURE
     if (coverPath != null) {
       try {
         final pictureBlock = await _createMetadataBlockPicture(coverPath);
         if (pictureBlock != null) {
-          // Escape special characters for shell
           final escapedBlock = pictureBlock.replaceAll('"', '\\"');
           cmdBuffer.write('-metadata METADATA_BLOCK_PICTURE="$escapedBlock" ');
           _log.d('Created METADATA_BLOCK_PICTURE for Opus (${pictureBlock.length} chars)');
@@ -424,19 +453,6 @@ class FFmpegService {
     return null;
   }
 
-  /// Create METADATA_BLOCK_PICTURE base64 string for OGG/Opus cover art
-  /// Format follows FLAC picture block specification:
-  /// - 4 bytes: picture type (3 = front cover)
-  /// - 4 bytes: MIME type length
-  /// - n bytes: MIME type string
-  /// - 4 bytes: description length
-  /// - n bytes: description string
-  /// - 4 bytes: width
-  /// - 4 bytes: height
-  /// - 4 bytes: color depth
-  /// - 4 bytes: colors used (0 for non-indexed)
-  /// - 4 bytes: picture data length
-  /// - n bytes: picture data
   static Future<String?> _createMetadataBlockPicture(String imagePath) async {
     try {
       final file = File(imagePath);
@@ -447,7 +463,6 @@ class FFmpegService {
       
       final imageData = await file.readAsBytes();
       
-      // Detect MIME type from file extension or magic bytes
       String mimeType;
       if (imagePath.toLowerCase().endsWith('.png')) {
         mimeType = 'image/png';
@@ -455,7 +470,6 @@ class FFmpegService {
                  imagePath.toLowerCase().endsWith('.jpeg')) {
         mimeType = 'image/jpeg';
       } else {
-        // Check magic bytes
         if (imageData.length >= 8 && 
             imageData[0] == 0x89 && imageData[1] == 0x50 && 
             imageData[2] == 0x4E && imageData[3] == 0x47) {
@@ -464,75 +478,61 @@ class FFmpegService {
                    imageData[0] == 0xFF && imageData[1] == 0xD8) {
           mimeType = 'image/jpeg';
         } else {
-          mimeType = 'image/jpeg'; // Default to JPEG
+          mimeType = 'image/jpeg';
         }
       }
       
       final mimeBytes = utf8.encode(mimeType);
-      const description = ''; // Empty description
+      const description = '';
       final descBytes = utf8.encode(description);
       
-      // Build the FLAC picture block
-      // Total size: 4 + 4 + mimeLen + 4 + descLen + 4 + 4 + 4 + 4 + 4 + imageLen
       final blockSize = 4 + 4 + mimeBytes.length + 4 + descBytes.length + 
                         4 + 4 + 4 + 4 + 4 + imageData.length;
       
       final buffer = ByteData(blockSize);
       var offset = 0;
       
-      // Picture type: 3 = Front cover
       buffer.setUint32(offset, 3, Endian.big);
       offset += 4;
       
-      // MIME type length
       buffer.setUint32(offset, mimeBytes.length, Endian.big);
       offset += 4;
       
-      // MIME type string
       final blockBytes = Uint8List(blockSize);
       blockBytes.setRange(0, offset, buffer.buffer.asUint8List());
       blockBytes.setRange(offset, offset + mimeBytes.length, mimeBytes);
       offset += mimeBytes.length;
       
-      // Description length
       final tempBuffer = ByteData(4);
       tempBuffer.setUint32(0, descBytes.length, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Description string
       blockBytes.setRange(offset, offset + descBytes.length, descBytes);
       offset += descBytes.length;
       
-      // Width (0 = unknown)
       tempBuffer.setUint32(0, 0, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Height (0 = unknown)
       tempBuffer.setUint32(0, 0, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Color depth (0 = unknown)
       tempBuffer.setUint32(0, 0, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Colors used (0 for non-indexed)
       tempBuffer.setUint32(0, 0, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Picture data length
       tempBuffer.setUint32(0, imageData.length, Endian.big);
       blockBytes.setRange(offset, offset + 4, tempBuffer.buffer.asUint8List());
       offset += 4;
       
-      // Picture data
       blockBytes.setRange(offset, offset + imageData.length, imageData);
       
-      // Base64 encode the entire block
       final base64String = base64Encode(blockBytes);
       
       return base64String;
@@ -549,7 +549,6 @@ class FFmpegService {
       final key = entry.key.toUpperCase();
       final value = entry.value;
       
-      // Map Vorbis comments to ID3v2 frame names
       switch (key) {
         case 'TITLE':
           id3Map['title'] = value;
@@ -583,7 +582,6 @@ class FFmpegService {
           id3Map['lyrics'] = value;
           break;
         default:
-          // Pass through other tags as-is
           id3Map[key.toLowerCase()] = value;
       }
     }

lib/services/platform_bridge.dart

@@ -323,7 +323,6 @@ class PlatformBridge {
     });
   }
 
-  /// Returns true if credentials are available (custom or env vars)
   static Future<bool> hasSpotifyCredentials() async {
     final result = await _channel.invokeMethod('hasSpotifyCredentials');
     return result as bool;
@@ -410,7 +409,6 @@ class PlatformBridge {
     return logs.map((e) => e as Map<String, dynamic>).toList();
   }
 
-  /// Get logs since a specific index (for incremental updates)
   static Future<Map<String, dynamic>> getGoLogsSince(int index) async {
     final result = await _channel.invokeMethod('getLogsSince', {'index': index});
     return jsonDecode(result as String) as Map<String, dynamic>;
@@ -561,7 +559,7 @@ class PlatformBridge {
     return list.map((e) => e as Map<String, dynamic>).toList();
   }
 
-  static Future<Map<String, dynamic>> downloadWithExtensions({
+static Future<Map<String, dynamic>> downloadWithExtensions({
     required String isrc,
     required String spotifyId,
     required String trackName,
@@ -584,8 +582,9 @@ class PlatformBridge {
     String? genre,
     String? label,
     String lyricsMode = 'embed',
+    String? preferredService,
   }) async {
-    _log.i('downloadWithExtensions: "$trackName" by $artistName${source != null ? ' (source: $source)' : ''}');
+    _log.i('downloadWithExtensions: "$trackName" by $artistName${source != null ? ' (source: $source)' : ''}${preferredService != null ? ' (service: $preferredService)' : ''}');
     final request = jsonEncode({
       'isrc': isrc,
       'spotify_id': spotifyId,
@@ -609,6 +608,7 @@ class PlatformBridge {
       'genre': genre ?? '',
       'label': label ?? '',
       'lyrics_mode': lyricsMode,
+      'service': preferredService ?? '',
     });
     
     final result = await _channel.invokeMethod('downloadWithExtensions', request);
@@ -795,7 +795,6 @@ class PlatformBridge {
     }
   }
 
-  /// Get extension home feed
   static Future<Map<String, dynamic>?> getExtensionHomeFeed(String extensionId) async {
     try {
       final result = await _channel.invokeMethod('getExtensionHomeFeed', {
@@ -809,7 +808,6 @@ class PlatformBridge {
     }
   }
 
-  /// Get extension browse categories
   static Future<Map<String, dynamic>?> getExtensionBrowseCategories(String extensionId) async {
     try {
       final result = await _channel.invokeMethod('getExtensionBrowseCategories', {

lib/utils/logger.dart

@@ -10,7 +10,7 @@ class LogEntry {
   final String tag;
   final String message;
   final String? error;
-  final bool isFromGo; // Track if this log came from Go backend
+  final bool isFromGo;
 
   LogEntry({
     required this.timestamp,
@@ -47,8 +47,6 @@ class LogBuffer extends ChangeNotifier {
   Timer? _goLogTimer;
   int _lastGoLogIndex = 0;
   
-  /// Whether logging is enabled (controlled by settings)
-  /// User must enable "Detailed Logging" in settings to capture logs
   static bool _loggingEnabled = false;
   static bool get loggingEnabled => _loggingEnabled;
   static set loggingEnabled(bool value) {
@@ -64,7 +62,6 @@ class LogBuffer extends ChangeNotifier {
   int get length => _entries.length;
 
   void add(LogEntry entry) {
-    // Skip adding if logging is disabled (except for errors which are always logged)
     if (!_loggingEnabled && entry.level != 'ERROR' && entry.level != 'FATAL') {
       return;
     }
@@ -76,7 +73,6 @@ class LogBuffer extends ChangeNotifier {
     notifyListeners();
   }
 
-  /// Start polling Go backend logs
   void startGoLogPolling() {
     _goLogTimer?.cancel();
     _goLogTimer = Timer.periodic(const Duration(milliseconds: 500), (_) async {
@@ -84,13 +80,11 @@ class LogBuffer extends ChangeNotifier {
     });
   }
 
-  /// Stop polling Go backend logs
   void stopGoLogPolling() {
     _goLogTimer?.cancel();
     _goLogTimer = null;
   }
 
-  /// Fetch logs from Go backend since last index
   Future<void> _fetchGoLogs() async {
     try {
       final result = await PlatformBridge.getGoLogsSince(_lastGoLogIndex);
@@ -103,7 +97,6 @@ class LogBuffer extends ChangeNotifier {
         final tag = log['tag'] as String? ?? 'Go';
         final message = log['message'] as String? ?? '';
         
-        // Parse timestamp (format: "15:04:05.000")
         DateTime parsedTime = DateTime.now();
         if (timestamp.isNotEmpty) {
           try {
@@ -221,7 +214,6 @@ class BufferedOutput extends LogOutput {
   }
 }
 
-/// Global logger instance for the app
 final log = Logger(
   printer: PrettyPrinter(
     methodCount: 0,

lib/widgets/download_service_picker.dart

@@ -10,11 +10,15 @@ class BuiltInService {
   final String id;
   final String label;
   final List<QualityOption> qualityOptions;
+  final bool isDisabled; // If true, service is grayed out (fallback only)
+  final String? disabledReason;
 
   const BuiltInService({
     required this.id,
     required this.label,
     required this.qualityOptions,
+    this.isDisabled = false,
+    this.disabledReason,
   });
 }
 
@@ -27,6 +31,7 @@ const _builtInServices = [
       QualityOption(id: 'LOSSLESS', label: 'FLAC Lossless', description: '16-bit / 44.1kHz'),
       QualityOption(id: 'HI_RES', label: 'Hi-Res FLAC', description: '24-bit / up to 96kHz'),
       QualityOption(id: 'HI_RES_LOSSLESS', label: 'Hi-Res FLAC Max', description: '24-bit / up to 192kHz'),
+      QualityOption(id: 'HIGH', label: 'Lossy 320kbps', description: 'MP3 or Opus (smaller files)'),
     ],
   ),
   BuiltInService(
@@ -46,16 +51,11 @@ const _builtInServices = [
       QualityOption(id: 'HI_RES', label: 'Hi-Res FLAC', description: '24-bit / up to 96kHz'),
       QualityOption(id: 'HI_RES_LOSSLESS', label: 'Hi-Res FLAC Max', description: '24-bit / up to 192kHz'),
     ],
+    isDisabled: true,
+    disabledReason: 'Fallback only',
   ),
 ];
 
-/// Lossy quality option (shown when enabled in settings)
-const _lossyQualityOption = QualityOption(
-  id: 'LOSSY',
-  label: 'Lossy',
-  description: 'MP3 320kbps or Opus 128kbps',
-);
-
 /// A reusable widget for selecting download service (built-in + extensions)
 class DownloadServicePicker extends ConsumerStatefulWidget {
   final String? trackName;
@@ -112,34 +112,21 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
 
   /// Get quality options for the selected service
   List<QualityOption> _getQualityOptions() {
-    final settings = ref.read(settingsProvider);
     final builtIn = _builtInServices.where((s) => s.id == _selectedService).firstOrNull;
     if (builtIn != null) {
-      // Add Lossy option if enabled in settings
-      if (settings.enableLossyOption) {
-        return [...builtIn.qualityOptions, _lossyQualityOption];
-      }
       return builtIn.qualityOptions;
     }
 
     final extensionState = ref.read(extensionProvider);
     final ext = extensionState.extensions.where((e) => e.id == _selectedService).firstOrNull;
     if (ext != null && ext.qualityOptions.isNotEmpty) {
-      // Add Lossy option for extensions too if enabled
-      if (settings.enableLossyOption) {
-        return [...ext.qualityOptions, _lossyQualityOption];
-      }
       return ext.qualityOptions;
     }
 
     // Default fallback options
-    final defaultOptions = [
+    return [
       const QualityOption(id: 'DEFAULT', label: 'Default Quality', description: 'Best available'),
     ];
-    if (settings.enableLossyOption) {
-      return [...defaultOptions, _lossyQualityOption];
-    }
-    return defaultOptions;
   }
 
   @override
@@ -188,7 +175,7 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
               ),
             ),
 
-            Padding(
+Padding(
               padding: const EdgeInsets.symmetric(horizontal: 20),
               child: Wrap(
                 spacing: 8,
@@ -196,9 +183,14 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
                 children: [
                   for (final service in _builtInServices)
                     _ServiceChip(
-                      label: service.label,
+                      label: service.isDisabled 
+                          ? '${service.label} (${service.disabledReason})'
+                          : service.label,
                       isSelected: _selectedService == service.id,
-                      onTap: () => setState(() => _selectedService = service.id),
+                      isDisabled: service.isDisabled,
+                      onTap: service.isDisabled 
+                          ? null 
+                          : () => setState(() => _selectedService = service.id),
                     ),
                   for (final ext in downloadExtensions)
                     _ServiceChip(
@@ -237,8 +229,13 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
                 subtitle: quality.description ?? '',
                 icon: _getQualityIcon(quality.id),
                 onTap: () {
-                  Navigator.pop(context);
+                  // For Tidal HIGH quality, show format picker first
-                  widget.onSelect(quality.id, _selectedService);
+                  if (_selectedService == 'tidal' && quality.id == 'HIGH') {
+                    _showLossyFormatPicker(context);
+                  } else {
+                    Navigator.pop(context);
+                    widget.onSelect(quality.id, _selectedService);
+                  }
                 },
               ),
 
@@ -257,9 +254,10 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
         return Icons.high_quality;
       case 'LOSSLESS':
         return Icons.music_note;
+      case 'HIGH':
+        return Icons.aod;
       case 'MP3_320':
       case 'MP3':
-      case 'LOSSY':
         return Icons.audiotrack;
       case 'OPUS':
       case 'OPUS_128':
@@ -268,6 +266,102 @@ class _DownloadServicePickerState extends ConsumerState<DownloadServicePicker> {
         return Icons.music_note;
     }
   }
+
+  void _showLossyFormatPicker(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+    final settings = ref.read(settingsProvider);
+    final currentFormat = settings.tidalHighFormat;
+
+    showModalBottomSheet(
+      context: context,
+      backgroundColor: colorScheme.surfaceContainerHigh,
+      shape: const RoundedRectangleBorder(
+        borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
+      ),
+      builder: (modalContext) => SafeArea(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            const SizedBox(height: 8),
+            Center(
+              child: Container(
+                width: 40,
+                height: 4,
+                decoration: BoxDecoration(
+                  color: colorScheme.onSurfaceVariant.withValues(alpha: 0.4),
+                  borderRadius: BorderRadius.circular(2),
+                ),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(24, 16, 24, 8),
+              child: Text(
+                'Select Lossy Format',
+                style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                  fontWeight: FontWeight.bold,
+                ),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(24, 0, 24, 16),
+              child: Text(
+                'Choose output format for 320kbps lossy download',
+                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                  color: colorScheme.onSurfaceVariant,
+                ),
+              ),
+            ),
+            ListTile(
+              contentPadding: const EdgeInsets.symmetric(horizontal: 24),
+              leading: Container(
+                padding: const EdgeInsets.all(10),
+                decoration: BoxDecoration(
+                  color: colorScheme.primaryContainer,
+                  borderRadius: BorderRadius.circular(12),
+                ),
+                child: Icon(Icons.audiotrack, color: colorScheme.onPrimaryContainer, size: 20),
+              ),
+              title: const Text('MP3 320kbps'),
+              subtitle: const Text('Best compatibility, ~10MB per track'),
+              trailing: currentFormat == 'mp3_320'
+                  ? Icon(Icons.check_circle, color: colorScheme.primary)
+                  : null,
+              onTap: () {
+                ref.read(settingsProvider.notifier).setTidalHighFormat('mp3_320');
+                Navigator.pop(modalContext); // Close format picker
+                Navigator.pop(context); // Close service picker
+                widget.onSelect('HIGH', _selectedService);
+              },
+            ),
+            ListTile(
+              contentPadding: const EdgeInsets.symmetric(horizontal: 24),
+              leading: Container(
+                padding: const EdgeInsets.all(10),
+                decoration: BoxDecoration(
+                  color: colorScheme.primaryContainer,
+                  borderRadius: BorderRadius.circular(12),
+                ),
+                child: Icon(Icons.graphic_eq, color: colorScheme.onPrimaryContainer, size: 20),
+              ),
+              title: const Text('Opus 128kbps'),
+              subtitle: const Text('Modern codec, ~4MB per track'),
+              trailing: currentFormat == 'opus_128'
+                  ? Icon(Icons.check_circle, color: colorScheme.primary)
+                  : null,
+              onTap: () {
+                ref.read(settingsProvider.notifier).setTidalHighFormat('opus_128');
+                Navigator.pop(modalContext); // Close format picker
+                Navigator.pop(context); // Close service picker
+                widget.onSelect('HIGH', _selectedService);
+              },
+            ),
+            const SizedBox(height: 16),
+          ],
+        ),
+      ),
+    );
+  }
 }
 
 
@@ -309,26 +403,32 @@ class _QualityOption extends StatelessWidget {
 class _ServiceChip extends StatelessWidget {
   final String label;
   final bool isSelected;
-  final VoidCallback onTap;
+  final VoidCallback? onTap;
   final String? iconPath;
+  final bool isDisabled;
 
   const _ServiceChip({
     required this.label,
     required this.isSelected,
     required this.onTap,
     this.iconPath,
+    this.isDisabled = false,
   });
 
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
     return GestureDetector(
-      onTap: onTap,
+      onTap: isDisabled ? null : onTap,
       child: AnimatedContainer(
         duration: const Duration(milliseconds: 200),
         padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
         decoration: BoxDecoration(
-          color: isSelected ? colorScheme.primaryContainer : colorScheme.surfaceContainerHighest,
+          color: isDisabled 
+              ? colorScheme.surfaceContainerHighest.withValues(alpha: 0.5)
+              : isSelected 
+                  ? colorScheme.primaryContainer 
+                  : colorScheme.surfaceContainerHighest,
           borderRadius: BorderRadius.circular(12),
           border: isSelected ? null : Border.all(color: colorScheme.outlineVariant.withValues(alpha: 0.5)),
         ),
@@ -346,7 +446,11 @@ class _ServiceChip extends StatelessWidget {
                   errorBuilder: (context, error, stackTrace) => Icon(
                     Icons.extension,
                     size: 18,
-                    color: isSelected ? colorScheme.onPrimaryContainer : colorScheme.onSurfaceVariant,
+                    color: isDisabled 
+                        ? colorScheme.onSurfaceVariant.withValues(alpha: 0.4)
+                        : isSelected 
+                            ? colorScheme.onPrimaryContainer 
+                            : colorScheme.onSurfaceVariant,
                   ),
                 ),
               ),
@@ -356,7 +460,11 @@ class _ServiceChip extends StatelessWidget {
               label,
               style: TextStyle(
                 fontWeight: isSelected ? FontWeight.w600 : FontWeight.normal,
-                color: isSelected ? colorScheme.onPrimaryContainer : colorScheme.onSurfaceVariant,
+                color: isDisabled 
+                    ? colorScheme.onSurfaceVariant.withValues(alpha: 0.4)
+                    : isSelected 
+                        ? colorScheme.onPrimaryContainer 
+                        : colorScheme.onSurfaceVariant,
               ),
             ),
           ],

pubspec.yaml

@@ -1,7 +1,7 @@
 name: spotiflac_android
 description: Download Spotify tracks in FLAC from Tidal, Qobuz & Amazon Music
 publish_to: "none"
-version: 3.3.1+68
+version: 3.3.5+70
 
 environment:
   sdk: ^3.10.0