Merge branch 'main' of https://github.com/zarzet/SpotiFLAC-Mobile

- Fix Flutter logs not appearing in release mode by bypassing Logger package
- Add detailed logging for Deezer search API calls
- Replace music_note icon with app logo on home screen
- Remove shadow/border from logo in About and Home screens
- Align icon size (40x40) with avatar in About page for consistent layout

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,123 @@
+name: Bug Report
+description: Report a bug or unexpected behavior
+title: "[Bug]: "
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to report a bug! Please fill out the form below.
+
+  - type: checkboxes
+    id: checklist
+    attributes:
+      label: Checklist
+      description: Please confirm the following before submitting
+      options:
+        - label: I have searched existing issues and this bug hasn't been reported yet
+          required: true
+        - label: I am using the latest version of SpotiFLAC
+          required: true
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Bug Description
+      description: A clear and concise description of what the bug is
+      placeholder: Describe the bug...
+    validations:
+      required: true
+
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to Reproduce
+      description: Steps to reproduce the behavior
+      placeholder: |
+        1. Go to '...'
+        2. Click on '...'
+        3. See error
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected Behavior
+      description: What did you expect to happen?
+      placeholder: Describe what you expected...
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual Behavior
+      description: What actually happened?
+      placeholder: Describe what actually happened...
+    validations:
+      required: true
+
+  - type: input
+    id: version
+    attributes:
+      label: App Version
+      description: Which version of SpotiFLAC are you using? (Check in Settings > About)
+      placeholder: "e.g., v2.2.0"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform
+      description: Which platform are you using?
+      options:
+        - Android
+        - iOS
+    validations:
+      required: true
+
+  - type: input
+    id: device
+    attributes:
+      label: Device & OS Version
+      description: What device and OS version are you using?
+      placeholder: "e.g., Samsung Galaxy S24, Android 14"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: download-service
+    attributes:
+      label: Download Service
+      description: Which download service were you using when the bug occurred?
+      options:
+        - Tidal
+        - Qobuz
+        - Amazon Music
+        - Deezer (search only)
+        - Not applicable
+    validations:
+      required: true
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs / Screenshots
+      description: |
+        If applicable, add logs or screenshots to help explain your problem.
+        
+        **To get logs:**
+        1. Go to Settings > Options > Detailed Logging (turn ON)
+        2. Reproduce the bug
+        3. Go to Settings > Logs
+        4. Tap Share button to export logs
+      placeholder: Paste logs or drag & drop screenshots here...
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Any other context about the problem
+      placeholder: Add any other context...

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: README
+    url: https://github.com/zarzet/SpotiFLAC-Mobile#readme
+    about: Check the README for setup instructions and FAQ

.github/ISSUE_TEMPLATE/download_issue.yml

@@ -0,0 +1,111 @@
+name: Download Issue
+description: Report issues with downloading specific tracks or albums
+title: "[Download]: "
+labels: ["download-issue"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Having trouble downloading a specific track or album? Please provide details below.
+
+  - type: checkboxes
+    id: checklist
+    attributes:
+      label: Checklist
+      description: Please confirm the following before submitting
+      options:
+        - label: I have tried downloading with a different service (Tidal/Qobuz/Amazon)
+          required: true
+        - label: I am using the latest version of SpotiFLAC
+          required: true
+
+  - type: dropdown
+    id: issue-type
+    attributes:
+      label: Issue Type
+      description: What kind of download issue are you experiencing?
+      options:
+        - Track not found on service
+        - Wrong track downloaded
+        - Download fails/errors
+        - Metadata incorrect
+        - Audio quality issue
+        - Other
+    validations:
+      required: true
+
+  - type: input
+    id: spotify-url
+    attributes:
+      label: Spotify URL
+      description: The Spotify URL of the track/album you're trying to download
+      placeholder: "https://open.spotify.com/track/..."
+    validations:
+      required: true
+
+  - type: input
+    id: track-info
+    attributes:
+      label: Track Info
+      description: Artist name and track title
+      placeholder: "Artist - Track Title"
+    validations:
+      required: true
+
+  - type: dropdown
+    id: download-service
+    attributes:
+      label: Download Service
+      description: Which service did you try to download from?
+      options:
+        - Tidal
+        - Qobuz
+        - Amazon Music
+        - All services
+    validations:
+      required: true
+
+  - type: dropdown
+    id: search-service
+    attributes:
+      label: Search Service
+      description: Which search service are you using?
+      options:
+        - Spotify
+        - Deezer
+    validations:
+      required: true
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: Describe the issue in detail
+      placeholder: |
+        What happened? What did you expect?
+        If wrong track was downloaded, what track was downloaded instead?
+    validations:
+      required: true
+
+  - type: input
+    id: version
+    attributes:
+      label: App Version
+      description: Which version of SpotiFLAC are you using?
+      placeholder: "e.g., v2.2.0"
+    validations:
+      required: true
+
+  - type: textarea
+    id: screenshots
+    attributes:
+      label: Screenshots / Logs
+      description: |
+        If applicable, add screenshots or logs.
+        
+        **To get logs:**
+        1. Go to Settings > Options > Detailed Logging (turn ON)
+        2. Try downloading the track again
+        3. Go to Settings > Logs
+        4. Tap Share button to export logs
+      placeholder: Drag & drop screenshots or paste logs here...

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,66 @@
+name: Feature Request
+description: Suggest a new feature or improvement
+title: "[Feature]: "
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for suggesting a feature! Please fill out the form below.
+
+  - type: checkboxes
+    id: checklist
+    attributes:
+      label: Checklist
+      description: Please confirm the following before submitting
+      options:
+        - label: I have searched existing issues and this feature hasn't been requested yet
+          required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem / Motivation
+      description: Is your feature request related to a problem? Please describe.
+      placeholder: "A clear description of what the problem is. Ex: I'm always frustrated when..."
+    validations:
+      required: true
+
+  - type: textarea
+    id: solution
+    attributes:
+      label: Proposed Solution
+      description: Describe the solution you'd like
+      placeholder: A clear description of what you want to happen...
+    validations:
+      required: true
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives Considered
+      description: Describe any alternative solutions or features you've considered
+      placeholder: Other approaches you've thought about...
+
+  - type: dropdown
+    id: category
+    attributes:
+      label: Category
+      description: What category does this feature fall under?
+      options:
+        - UI/UX Improvement
+        - Download Feature
+        - New Service Integration
+        - Metadata/Tagging
+        - Performance
+        - Settings/Configuration
+        - Other
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Add any other context, mockups, or screenshots about the feature request
+      placeholder: Add any other context or screenshots...

.github/workflows/android-build.yml

@@ -1,75 +0,0 @@
-name: Android Build
-
-on:
-  push:
-    tags:
-      - 'v*'
-  workflow_dispatch:
-
-jobs:
-  build-android:
-    runs-on: ubuntu-latest
-    
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-
-      - name: Setup Java
-        uses: actions/setup-java@v4
-        with:
-          distribution: 'temurin'
-          java-version: '17'
-
-      - name: Setup Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: '1.21'
-          cache-dependency-path: go_backend/go.sum
-
-      - name: Install Android SDK & NDK
-        uses: android-actions/setup-android@v3
-
-      - name: Install gomobile
-        run: |
-          go install golang.org/x/mobile/cmd/gomobile@latest
-          gomobile init
-
-      - name: Build Go backend for Android
-        working-directory: go_backend
-        run: |
-          mkdir -p ../android/app/libs
-          gomobile bind -target=android -androidapi 24 -o ../android/app/libs/gobackend.aar .
-        env:
-          CGO_ENABLED: 1
-
-      - name: Setup Flutter
-        uses: subosito/flutter-action@v2
-        with:
-          channel: 'stable'
-          cache: true
-
-      - name: Get Flutter dependencies
-        run: flutter pub get
-
-      - name: Generate app icons
-        run: dart run flutter_launcher_icons
-
-      - name: Build APK (Release)
-        run: flutter build apk --release
-
-      - name: Build App Bundle (Release)
-        run: flutter build appbundle --release
-
-      - name: Upload APK artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: SpotiFLAC-Android-APK
-          path: build/app/outputs/flutter-apk/app-release.apk
-          retention-days: 30
-
-      - name: Upload AAB artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: SpotiFLAC-Android-AAB
-          path: build/app/outputs/bundle/release/app-release.aab
-          retention-days: 30

.github/workflows/auto-release.yml

@@ -1,69 +0,0 @@
-name: Auto Release on Version Bump
-
-on:
-  push:
-    branches: [main]
-    paths:
-      - 'pubspec.yaml'
-
-jobs:
-  check-version:
-    runs-on: ubuntu-latest
-    outputs:
-      version_changed: ${{ steps.check.outputs.changed }}
-      new_version: ${{ steps.check.outputs.version }}
-    
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 2
-
-      - name: Check if version changed
-        id: check
-        run: |
-          # Get current version
-          CURRENT_VERSION=$(grep '^version:' pubspec.yaml | sed 's/version: //' | cut -d'+' -f1)
-          
-          # Get previous version
-          git show HEAD~1:pubspec.yaml > /tmp/old_pubspec.yaml 2>/dev/null || echo "version: 0.0.0" > /tmp/old_pubspec.yaml
-          PREVIOUS_VERSION=$(grep '^version:' /tmp/old_pubspec.yaml | sed 's/version: //' | cut -d'+' -f1)
-          
-          echo "Current version: $CURRENT_VERSION"
-          echo "Previous version: $PREVIOUS_VERSION"
-          
-          if [ "$CURRENT_VERSION" != "$PREVIOUS_VERSION" ]; then
-            echo "Version changed!"
-            echo "changed=true" >> $GITHUB_OUTPUT
-            echo "version=v$CURRENT_VERSION" >> $GITHUB_OUTPUT
-          else
-            echo "Version unchanged"
-            echo "changed=false" >> $GITHUB_OUTPUT
-          fi
-
-  create-tag-and-trigger-release:
-    needs: check-version
-    if: needs.check-version.outputs.version_changed == 'true'
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-      actions: write
-    
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-
-      - name: Create and push tag
-        run: |
-          git config user.name "github-actions[bot]"
-          git config user.email "github-actions[bot]@users.noreply.github.com"
-          git tag ${{ needs.check-version.outputs.new_version }}
-          git push origin ${{ needs.check-version.outputs.new_version }}
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Trigger Release workflow
-        run: |
-          gh workflow run release.yml -f version=${{ needs.check-version.outputs.new_version }}
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/auto-tag.yml

@@ -0,0 +1,77 @@
+name: Auto Tag on Version Change
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'pubspec.yaml'
+
+jobs:
+  check-version:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 2  # Need previous commit to compare
+
+      - name: Get current version
+        id: current
+        run: |
+          VERSION=$(grep '^version:' pubspec.yaml | sed 's/version: //' | cut -d'+' -f1)
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "Current version: $VERSION"
+
+      - name: Get previous version
+        id: previous
+        run: |
+          git checkout HEAD~1 -- pubspec.yaml 2>/dev/null || echo "version: 0.0.0" > pubspec.yaml.old
+          if [ -f pubspec.yaml.old ]; then
+            VERSION=$(grep '^version:' pubspec.yaml.old | sed 's/version: //' | cut -d'+' -f1)
+          else
+            VERSION=$(grep '^version:' pubspec.yaml | sed 's/version: //' | cut -d'+' -f1)
+          fi
+          git checkout HEAD -- pubspec.yaml
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "Previous version: $VERSION"
+
+      - name: Check if version changed
+        id: check
+        run: |
+          CURRENT="${{ steps.current.outputs.version }}"
+          PREVIOUS="${{ steps.previous.outputs.version }}"
+          
+          if [ "$CURRENT" != "$PREVIOUS" ]; then
+            echo "Version changed from $PREVIOUS to $CURRENT"
+            echo "changed=true" >> $GITHUB_OUTPUT
+          else
+            echo "Version unchanged: $CURRENT"
+            echo "changed=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Check if tag exists
+        id: tag_exists
+        if: steps.check.outputs.changed == 'true'
+        run: |
+          TAG="v${{ steps.current.outputs.version }}"
+          if git ls-remote --tags origin | grep -q "refs/tags/$TAG"; then
+            echo "Tag $TAG already exists"
+            echo "exists=true" >> $GITHUB_OUTPUT
+          else
+            echo "Tag $TAG does not exist"
+            echo "exists=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Create and push tag
+        if: steps.check.outputs.changed == 'true' && steps.tag_exists.outputs.exists == 'false'
+        run: |
+          TAG="v${{ steps.current.outputs.version }}"
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git tag -a "$TAG" -m "Release $TAG"
+          git push origin "$TAG"
+          echo "Created and pushed tag: $TAG"

.github/workflows/ios-build.yml

@@ -1,118 +0,0 @@
-name: iOS Build
-
-on:
-  push:
-    tags:
-      - 'v*'
-  workflow_dispatch:
-
-jobs:
-  build-ios:
-    runs-on: macos-latest
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-
-      - name: Setup Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: '1.21'
-          cache-dependency-path: go_backend/go.sum
-
-      - name: Install gomobile
-        run: |
-          go install golang.org/x/mobile/cmd/gomobile@latest
-          gomobile init
-
-      - name: Build Go backend for iOS (XCFramework)
-        working-directory: go_backend
-        run: |
-          mkdir -p ../ios/Frameworks
-          gomobile bind -target=ios -o ../ios/Frameworks/Gobackend.xcframework .
-        env:
-          CGO_ENABLED: 1
-
-      - name: Verify XCFramework created
-        run: |
-          echo "=== Checking XCFramework ==="
-          ls -la ios/Frameworks/
-          ls -la ios/Frameworks/Gobackend.xcframework/ || (echo "ERROR: XCFramework not found!" && exit 1)
-
-      - name: Add XCFramework to Xcode project
-        run: |
-          # Install xcodeproj gem for modifying Xcode project
-          sudo gem install xcodeproj
-          
-          # Create Ruby script to add framework
-          cat > add_framework.rb << 'EOF'
-          require 'xcodeproj'
-          
-          project_path = 'ios/Runner.xcodeproj'
-          project = Xcodeproj::Project.open(project_path)
-          
-          # Get the main target
-          target = project.targets.find { |t| t.name == 'Runner' }
-          
-          # Get or create Frameworks group
-          frameworks_group = project.main_group.find_subpath('Frameworks', true)
-          frameworks_group ||= project.main_group.new_group('Frameworks')
-          
-          # Add XCFramework reference
-          framework_path = 'Frameworks/Gobackend.xcframework'
-          framework_ref = frameworks_group.new_file(framework_path, :project)
-          
-          # Add to frameworks build phase
-          frameworks_build_phase = target.frameworks_build_phase
-          frameworks_build_phase.add_file_reference(framework_ref)
-          
-          # Add to embed frameworks build phase
-          embed_phase = target.build_phases.find { |p| p.is_a?(Xcodeproj::Project::Object::PBXCopyFilesBuildPhase) && p.name == 'Embed Frameworks' }
-          if embed_phase
-            build_file = embed_phase.add_file_reference(framework_ref)
-            build_file.settings = { 'ATTRIBUTES' => ['CodeSignOnCopy', 'RemoveHeadersOnCopy'] }
-          end
-          
-          project.save
-          puts "Successfully added Gobackend.xcframework to Xcode project"
-          EOF
-          
-          ruby add_framework.rb
-
-      - name: Setup Flutter
-        uses: subosito/flutter-action@v2
-        with:
-          channel: 'stable'
-          cache: true
-
-      - name: Get Flutter dependencies
-        run: flutter pub get
-
-      - name: Generate app icons
-        run: dart run flutter_launcher_icons
-
-      - name: Build iOS (no codesign)
-        run: flutter build ios --release --no-codesign
-
-      - name: Create IPA (unsigned)
-        run: |
-          mkdir -p build/ios/ipa
-          cd build/ios/iphoneos
-          mkdir Payload
-          cp -r Runner.app Payload/
-          zip -r ../ipa/SpotiFLAC-unsigned.ipa Payload
-          rm -rf Payload
-
-      - name: Upload IPA artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: SpotiFLAC-iOS-unsigned
-          path: build/ios/ipa/SpotiFLAC-unsigned.ipa
-          retention-days: 30
-
-      - name: Upload XCFramework artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: Gobackend-XCFramework
-          path: ios/Frameworks/Gobackend.xcframework
-          retention-days: 30

.github/workflows/release.yml

@@ -3,13 +3,13 @@ name: Release
 on:
   push:
     tags:
-      - 'v*'
+      - "v*"
   workflow_dispatch:
     inputs:
       version:
-        description: 'Version tag (e.g., v1.0.0)'
+        description: "Version tag (e.g., v1.0.0)"
         required: true
-        default: 'v1.0.0'
+        default: "v1.0.0"
 
 jobs:
   # Get version first (quick job)
@@ -17,35 +17,61 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       version: ${{ steps.version.outputs.version }}
+      is_prerelease: ${{ steps.version.outputs.is_prerelease }}
     steps:
       - name: Get version
         id: version
         run: |
           if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
-            echo "version=${{ github.event.inputs.version }}" >> $GITHUB_OUTPUT
+            VERSION="${{ github.event.inputs.version }}"
           else
-            echo "version=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+            VERSION="${GITHUB_REF#refs/tags/}"
+          fi
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+
+          # Check if version contains -preview, -beta, -rc, or -alpha (NOT -hotfix)
+          VERSION_LOWER=$(echo "$VERSION" | tr '[:upper:]' '[:lower:]')
+          if [[ "$VERSION_LOWER" == *"-preview"* ]] || [[ "$VERSION_LOWER" == *"-beta"* ]] || [[ "$VERSION_LOWER" == *"-rc"* ]] || [[ "$VERSION_LOWER" == *"-alpha"* ]]; then
+            echo "is_prerelease=true" >> $GITHUB_OUTPUT
+            echo "Detected pre-release version: $VERSION"
+          else
+            echo "is_prerelease=false" >> $GITHUB_OUTPUT
+            echo "Detected stable version: $VERSION"
           fi
 
   # Android and iOS build in PARALLEL
   build-android:
     runs-on: ubuntu-latest
     needs: get-version
-    
+
     steps:
+      - name: Free disk space
+        run: |
+          # Remove large unused tools (~15GB total)
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /opt/hostedtoolcache/CodeQL
+          sudo rm -rf /usr/local/share/boost
+          sudo rm -rf /usr/share/swift
+          sudo rm -rf /usr/local/.ghcup
+          # Clean docker images
+          sudo docker image prune --all --force
+          # Show available space
+          df -h
+
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Setup Java
         uses: actions/setup-java@v4
         with:
-          distribution: 'temurin'
-          java-version: '17'
+          distribution: "temurin"
+          java-version: "17"
 
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.21'
+          go-version: "1.21"
           cache-dependency-path: go_backend/go.sum
 
       # Cache Gradle for faster builds
@@ -59,7 +85,20 @@ jobs:
           restore-keys: gradle-${{ runner.os }}-
 
       - name: Install Android SDK & NDK
-        uses: android-actions/setup-android@v3
+        run: |
+          # Use pre-installed Android SDK on GitHub runners
+          echo "ANDROID_HOME=$ANDROID_HOME"
+          echo "ANDROID_SDK_ROOT=$ANDROID_SDK_ROOT"
+
+          # Accept licenses
+          yes | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager --licenses || true
+
+          # Install NDK r27d LTS (required for 16KB page size support on Android 15+)
+          # Platform android-36 and build-tools 36.0.0 for targetSdk 36 (Android 16)
+          $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;27.3.13750724" "platforms;android-36" "build-tools;36.0.0"
+
+          # Set NDK path
+          echo "ANDROID_NDK_HOME=$ANDROID_HOME/ndk/27.3.13750724" >> $GITHUB_ENV
 
       - name: Install gomobile
         run: |
@@ -77,7 +116,7 @@ jobs:
       - name: Setup Flutter
         uses: subosito/flutter-action@v2
         with:
-          channel: 'stable'
+          channel: "stable"
           cache: true
 
       - name: Get Flutter dependencies
@@ -86,16 +125,36 @@ jobs:
       - name: Generate app icons
         run: dart run flutter_launcher_icons
 
-      - name: Build APK (Release)
-        run: flutter build apk --release --split-per-abi
+      - name: Build APK (Release - unsigned)
+        run: |
+          flutter build apk --release --split-per-abi || true
+          # Verify APKs were created
+          ls -la build/app/outputs/flutter-apk/
+          if [ ! -f "build/app/outputs/flutter-apk/app-arm64-v8a-release.apk" ]; then
+            echo "ERROR: APK not found!"
+            exit 1
+          fi
+
+      - name: Sign APKs
+        uses: r0adkll/sign-android-release@v1
+        id: sign_arm64
+        with:
+          releaseDirectory: build/app/outputs/flutter-apk
+          signingKeyBase64: ${{ secrets.KEYSTORE_BASE64 }}
+          alias: ${{ secrets.KEY_ALIAS }}
+          keyStorePassword: ${{ secrets.KEYSTORE_PASSWORD }}
+          keyPassword: ${{ secrets.KEY_PASSWORD }}
+        env:
+          BUILD_TOOLS_VERSION: "36.0.0"
 
       - name: Rename APKs
         run: |
           VERSION=${{ needs.get-version.outputs.version }}
           cd build/app/outputs/flutter-apk
-          mv app-arm64-v8a-release.apk SpotiFLAC-${VERSION}-arm64.apk || true
-          mv app-armeabi-v7a-release.apk SpotiFLAC-${VERSION}-arm32.apk || true
-          mv app-release.apk SpotiFLAC-${VERSION}-universal.apk || true
+          # Signed files have -signed suffix
+          mv app-arm64-v8a-release-signed.apk SpotiFLAC-${VERSION}-arm64.apk || mv app-arm64-v8a-release.apk SpotiFLAC-${VERSION}-arm64.apk || true
+          mv app-armeabi-v7a-release-signed.apk SpotiFLAC-${VERSION}-arm32.apk || mv app-armeabi-v7a-release.apk SpotiFLAC-${VERSION}-arm32.apk || true
+          mv app-release-signed.apk SpotiFLAC-${VERSION}-universal.apk || mv app-release.apk SpotiFLAC-${VERSION}-universal.apk || true
           ls -la
 
       - name: Upload APK artifact
@@ -106,8 +165,8 @@ jobs:
 
   build-ios:
     runs-on: macos-latest
-    needs: get-version  # Only depends on version, NOT android build!
-    
+    needs: get-version # Only depends on version, NOT android build!
+
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -115,7 +174,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: '1.21'
+          go-version: "1.21"
           cache-dependency-path: go_backend/go.sum
 
       # Cache CocoaPods
@@ -143,53 +202,70 @@ jobs:
         run: |
           ls -la ios/Frameworks/
           ls -la ios/Frameworks/Gobackend.xcframework/ || (echo "ERROR: XCFramework not found!" && exit 1)
-          
+
       - name: Add XCFramework to Xcode project
         run: |
           # Install xcodeproj gem for modifying Xcode project
           sudo gem install xcodeproj
-          
+
           # Create Ruby script to add framework
           cat > add_framework.rb << 'EOF'
           require 'xcodeproj'
-          
+
           project_path = 'ios/Runner.xcodeproj'
           project = Xcodeproj::Project.open(project_path)
-          
+
           # Get the main target
           target = project.targets.find { |t| t.name == 'Runner' }
-          
+
           # Get or create Frameworks group
           frameworks_group = project.main_group.find_subpath('Frameworks', true)
           frameworks_group ||= project.main_group.new_group('Frameworks')
-          
+
           # Add XCFramework reference
           framework_path = 'Frameworks/Gobackend.xcframework'
           framework_ref = frameworks_group.new_file(framework_path, :project)
-          
+
           # Add to frameworks build phase
           frameworks_build_phase = target.frameworks_build_phase
           frameworks_build_phase.add_file_reference(framework_ref)
-          
+
           # Add to embed frameworks build phase
           embed_phase = target.build_phases.find { |p| p.is_a?(Xcodeproj::Project::Object::PBXCopyFilesBuildPhase) && p.name == 'Embed Frameworks' }
           if embed_phase
             build_file = embed_phase.add_file_reference(framework_ref)
             build_file.settings = { 'ATTRIBUTES' => ['CodeSignOnCopy', 'RemoveHeadersOnCopy'] }
           end
-          
+
           project.save
           puts "Successfully added Gobackend.xcframework to Xcode project"
           EOF
-          
+
           ruby add_framework.rb
 
       - name: Setup Flutter
         uses: subosito/flutter-action@v2
         with:
-          channel: 'stable'
+          channel: "stable"
           cache: true
 
+      # Swap pubspec for iOS build (includes ffmpeg_kit_flutter)
+      - name: Use iOS pubspec with FFmpeg plugin
+        run: |
+          cp pubspec.yaml pubspec_android_backup.yaml
+          cp pubspec_ios.yaml pubspec.yaml
+          echo "Swapped to iOS pubspec with ffmpeg_kit_flutter"
+
+      # Swap FFmpeg service for iOS
+      - name: Use iOS FFmpeg service
+        run: |
+          cp lib/services/ffmpeg_service.dart lib/services/ffmpeg_service_android.dart
+          cp build_assets/ffmpeg_service_ios.dart lib/services/ffmpeg_service.dart
+          # Update class name in the swapped file
+          sed -i '' 's/FFmpegServiceIOS/FFmpegService/g' lib/services/ffmpeg_service.dart
+          sed -i '' 's/FFmpegResultIOS/FFmpegResult/g' lib/services/ffmpeg_service.dart
+          echo "Swapped to iOS FFmpeg service"
+
       - name: Get Flutter dependencies
         run: flutter pub get
 
@@ -197,18 +273,44 @@ jobs:
         run: dart run flutter_launcher_icons
 
       - name: Build iOS (unsigned)
-        run: flutter build ios --release --no-codesign
+        run: |
+          # Build Flutter iOS without codesigning
+          flutter build ios --release --no-codesign --config-only
+
+          # Use xcodebuild with code signing disabled
+          cd ios
+          xcodebuild -workspace Runner.xcworkspace \
+            -scheme Runner \
+            -configuration Release \
+            -sdk iphoneos \
+            -destination 'generic/platform=iOS' \
+            -archivePath build/Runner.xcarchive \
+            archive \
+            CODE_SIGNING_ALLOWED=NO \
+            CODE_SIGNING_REQUIRED=NO \
+            CODE_SIGN_IDENTITY="" \
+            DEVELOPMENT_TEAM=""
 
       - name: Create IPA
         run: |
           VERSION=${{ needs.get-version.outputs.version }}
           mkdir -p build/ios/ipa
-          cd build/ios/iphoneos
+          cd ios/build/Runner.xcarchive/Products/Applications
           mkdir Payload
           cp -r Runner.app Payload/
-          zip -r ../ipa/SpotiFLAC-${VERSION}-ios-unsigned.ipa Payload
+          # Use absolute path to avoid relative path issues
+          zip -r $GITHUB_WORKSPACE/build/ios/ipa/SpotiFLAC-${VERSION}-ios-unsigned.ipa Payload
           rm -rf Payload
 
+      - name: Verify IPA created
+        run: |
+          ls -la build/ios/ipa/
+          VERSION=${{ needs.get-version.outputs.version }}
+          if [ ! -f "build/ios/ipa/SpotiFLAC-${VERSION}-ios-unsigned.ipa" ]; then
+            echo "ERROR: IPA not created!"
+            exit 1
+          fi
+
       - name: Upload IPA artifact
         uses: actions/upload-artifact@v4
         with:
@@ -220,8 +322,36 @@ jobs:
     needs: [get-version, build-android, build-ios]
     permissions:
       contents: write
-    
+
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Extract changelog for version
+        id: changelog
+        run: |
+          VERSION=${{ needs.get-version.outputs.version }}
+          VERSION_NUM=${VERSION#v}  # Remove 'v' prefix
+
+          echo "Looking for version: $VERSION_NUM"
+
+          # Extract changelog section for this version using sed
+          # Find the line with version, then print until next version header or end
+          CHANGELOG=$(sed -n "/^## \[$VERSION_NUM\]/,/^## \[/{ /^## \[$VERSION_NUM\]/d; /^## \[/d; p; }" CHANGELOG.md)
+
+          # If no changelog found, use default message
+          if [ -z "$CHANGELOG" ]; then
+            echo "No changelog found for version $VERSION_NUM"
+            CHANGELOG="See CHANGELOG.md for details."
+          else
+            echo "Found changelog content"
+          fi
+
+          # Save to file for multiline support
+          echo "$CHANGELOG" > /tmp/changelog.txt
+          echo "Extracted changelog:"
+          cat /tmp/changelog.txt
+
       - name: Download Android APK
         uses: actions/download-artifact@v4
         with:
@@ -234,26 +364,49 @@ jobs:
           name: ios-ipa
           path: ./release
 
+      - name: Prepare release body
+        run: |
+          VERSION=${{ needs.get-version.outputs.version }}
+          cat > /tmp/release_body.txt << 'HEADER'
+          ### What's New
+          HEADER
+
+          cat /tmp/changelog.txt >> /tmp/release_body.txt
+
+          REPO_OWNER="${{ github.repository_owner }}"
+          REPO_NAME="${{ github.event.repository.name }}"
+          
+          cat >> /tmp/release_body.txt << FOOTER
+
+          ---
+
+          ### Downloads
+
+          #### Android
+          - **arm64**: \`SpotiFLAC-${VERSION}-arm64.apk\` (recommended for modern devices)
+          - **arm32**: \`SpotiFLAC-${VERSION}-arm32.apk\` (older devices)
+
+          #### iOS
+          - **iOS**: \`SpotiFLAC-${VERSION}-ios-unsigned.ipa\` (sideload required)
+
+          ### Installation
+          **Android**: Enable "Install from unknown sources" and install the APK
+          **iOS**: Use AltStore, Sideloadly, or similar tools to sideload the IPA
+
+          ![arm64](https://img.shields.io/github/downloads/${REPO_OWNER}/${REPO_NAME}/${VERSION}/SpotiFLAC-${VERSION}-arm64.apk?style=flat-square&logo=android&label=arm64&color=3DDC84) ![arm32](https://img.shields.io/github/downloads/${REPO_OWNER}/${REPO_NAME}/${VERSION}/SpotiFLAC-${VERSION}-arm32.apk?style=flat-square&logo=android&label=arm32&color=3DDC84) ![iOS](https://img.shields.io/github/downloads/${REPO_OWNER}/${REPO_NAME}/${VERSION}/SpotiFLAC-${VERSION}-ios-unsigned.ipa?style=flat-square&logo=apple&label=iOS&color=0078D6)
+          FOOTER
+
+          echo "Release body:"
+          cat /tmp/release_body.txt
+
       - name: Create Release
         uses: softprops/action-gh-release@v1
         with:
           tag_name: ${{ needs.get-version.outputs.version }}
           name: SpotiFLAC ${{ needs.get-version.outputs.version }}
-          body: |
-            ## SpotiFLAC ${{ needs.get-version.outputs.version }}
-            
-            Download Spotify tracks in FLAC quality from Tidal, Qobuz & Amazon Music.
-            
-            ### Downloads
-            - **Android (arm64)**: `SpotiFLAC-${{ needs.get-version.outputs.version }}-arm64.apk` (recommended)
-            - **Android (arm32)**: `SpotiFLAC-${{ needs.get-version.outputs.version }}-arm32.apk` (older devices)
-            - **iOS**: `SpotiFLAC-${{ needs.get-version.outputs.version }}-ios-unsigned.ipa` (sideload required)
-            
-            ### Installation
-            **Android**: Enable "Install from unknown sources" and install the APK
-            **iOS**: Use AltStore, Sideloadly, or similar tools to sideload the IPA
+          body_path: /tmp/release_body.txt
           files: ./release/*
           draft: false
-          prerelease: false
+          prerelease: ${{ needs.get-version.outputs.is_prerelease == 'true' }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -7,8 +7,46 @@ Thumbs.db
 .vscode/
 *.iml
 
-# Kiro specs (optional - remove if you want to track specs)
-# .kiro/
+# Kiro specs (development only)
+.kiro/
 
-# Reference folder (if you don't want to include it)
-# referensi/
+# Reference folder (development only)
+referensi/
+
+# Old spotiflac_android folder (moved to root)
+spotiflac_android/
+
+# Flutter/Dart
+.dart_tool/
+.packages
+build/
+*.lock
+!pubspec.lock
+.flutter-plugins
+.flutter-plugins-dependencies
+.metadata
+*.apk
+
+# Go backend build artifacts
+go_backend/*.aar
+go_backend/*.jar
+go_backend/*.exe
+go_backend/*.xcframework/
+
+# Android
+android/.gradle/
+android/app/libs/gobackend.aar
+android/local.properties
+android/*.iml
+android/key.properties
+android/*.jks
+android/*.keystore
+android/app/*.jks
+
+# iOS
+ios/Frameworks/
+ios/Pods/
+ios/.symlinks/
+ios/Flutter/Flutter.framework/
+ios/Flutter/Flutter.podspec
+android/app/libs/gobackend-sources.jar

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 zarzet
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,4 +1,5 @@
 [![GitHub All Releases](https://img.shields.io/github/downloads/zarzet/SpotiFLAC-Mobile/total?style=for-the-badge)](https://github.com/zarzet/SpotiFLAC-Mobile/releases)
+[![VirusTotal](https://img.shields.io/badge/VirusTotal-Safe-brightgreen?style=for-the-badge&logo=virustotal)](https://www.virustotal.com/gui/file/09c6260e9ebaf2ff0d15f30deda939642f41887f11aad602ac697cb37fa0308c/)
 
 <div align="center">
 
@@ -16,19 +17,40 @@ Get Spotify tracks in true FLAC from Tidal, Qobuz & Amazon Music — no account
 ## Screenshots
 
 <p align="center">
-  <img src="docs/Screenshot_20260101-210622_SpotiFLAC.png" width="200" />
-  <img src="docs/Screenshot_20260101-210626_SpotiFLAC.png" width="200" />
-  <img src="docs/Screenshot_20260101-210633_SpotiFLAC.png" width="200" />
-  <img src="docs/Screenshot_20260101-210653_SpotiFLAC.png" width="200" />
+  <img src="assets/images/1.jpg?v=2" width="200" />
+  <img src="assets/images/2.jpg?v=2" width="200" />
+  <img src="assets/images/3.jpg?v=2" width="200" />
+  <img src="assets/images/4.jpg?v=2" width="200" />
 </p>
 
+## Metadata Source
+
+SpotiFLAC supports two metadata sources for searching tracks:
+
+| Source | Pros | Cons |
+|--------|------|------|
+| **Deezer** (Default) | No developer account needed, rate limit per user IP | Slightly less comprehensive catalog |
+| **Spotify** | More comprehensive catalog, better search results | Requires developer API credentials to avoid rate limiting |
+
+### Using Spotify
+To use Spotify as your search source without hitting rate limits:
+1. Create a Spotify Developer account at [developer.spotify.com](https://developer.spotify.com)
+2. Create an app to get your Client ID and Client Secret
+3. Go to **Settings > Options > Spotify API > Change from Deezer to Spotify > Input Custom Credentials**
+4. Enter your Client ID and Secret
+5. Change **Search Source** to Spotify
+
 ## Other project
 
 ### [SpotiFLAC (Desktop)](https://github.com/afkarxyz/SpotiFLAC)
 Get Spotify tracks in true FLAC from Tidal, Qobuz & Amazon Music for Windows, macOS & Linux
 
+[![Ko-fi](https://img.shields.io/badge/Ko--fi-Support%20Me-FF5E5B?style=for-the-badge&logo=ko-fi&logoColor=white)](https://ko-fi.com/zarzet)
+
 ## Disclaimer
 
+> **iOS Support**: This app is primarily tested on Android. iOS support is experimental and may have bugs — the developer is too poor to afford an iPhone for proper testing. If you encounter issues on iOS, please report them!
+
 This project is for **educational and private use only**. The developer does not condone or encourage copyright infringement.
 
 **SpotiFLAC** is a third-party tool and is not affiliated with, endorsed by, or connected to Spotify, Tidal, Qobuz, Amazon Music, or any other streaming service.

android/app/build.gradle.kts

@@ -1,3 +1,6 @@
+import java.util.Properties
+import java.io.FileInputStream
+
 plugins {
     id("com.android.application")
     id("kotlin-android")
@@ -5,6 +8,13 @@ plugins {
     id("dev.flutter.flutter-gradle-plugin")
 }
 
+// Load keystore properties for local builds
+val keystorePropertiesFile = rootProject.file("key.properties")
+val keystoreProperties = Properties()
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
+}
+
 android {
     namespace = "com.zarz.spotiflac"
     compileSdk = flutter.compileSdkVersion
@@ -22,16 +32,25 @@ android {
         }
     }
 
+    signingConfigs {
+        if (keystorePropertiesFile.exists()) {
+            create("release") {
+                keyAlias = keystoreProperties.getProperty("keyAlias")
+                keyPassword = keystoreProperties.getProperty("keyPassword")
+                storeFile = file(keystoreProperties.getProperty("storeFile"))
+                storePassword = keystoreProperties.getProperty("storePassword")
+            }
+        }
+    }
+
     defaultConfig {
         applicationId = "com.zarz.spotiflac"
         minSdk = flutter.minSdkVersion
-        targetSdk = 34
+        targetSdk = 36
         versionCode = flutter.versionCode
         versionName = flutter.versionName
         multiDexEnabled = true
         
-        // Only include arm64-v8a for smaller APK (most modern devices)
-        // Remove this line if you need to support older 32-bit devices
         ndk {
             abiFilters += listOf("arm64-v8a", "armeabi-v7a")
         }
@@ -39,8 +58,13 @@ android {
 
     buildTypes {
         release {
-            signingConfig = signingConfigs.getByName("debug")
-            // Enable code shrinking and resource shrinking
+            // For local builds: use release signing if key.properties exists
+            // For CI builds: APK is signed by GitHub Action after build
+            signingConfig = if (keystorePropertiesFile.exists()) {
+                signingConfigs.getByName("release")
+            } else {
+                signingConfigs.getByName("debug")
+            }
             isMinifyEnabled = true
             isShrinkResources = true
             proguardFiles(
@@ -72,8 +96,11 @@ repositories {
 }
 
 dependencies {
-    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.0.4")
-    implementation(files("libs/gobackend.aar"))
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
+    
+    // Include all AAR and JAR files from libs folder
+    implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar", "*.aar"))))
+    
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3")
     implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.7.0")
 }

android/app/proguard-rules.pro

@@ -6,6 +6,14 @@
 -keep class io.flutter.** { *; }
 -keep class io.flutter.plugins.** { *; }
 
+# Ignore missing Play Core classes (not used, but referenced by Flutter)
+-dontwarn com.google.android.play.core.splitcompat.**
+-dontwarn com.google.android.play.core.splitinstall.**
+-dontwarn com.google.android.play.core.tasks.**
+
+# Ignore missing javax.xml.stream (not used on Android)
+-dontwarn javax.xml.stream.**
+
 # Go backend (gobackend.aar)
 -keep class gobackend.** { *; }
 -keep class go.** { *; }
@@ -14,6 +22,9 @@
 -keep class com.arthenica.ffmpegkit.** { *; }
 -keep class com.arthenica.smartexception.** { *; }
 
+# Apache Tika (if used by FFmpeg)
+-dontwarn org.apache.tika.**
+
 # Keep native methods
 -keepclasseswithmembernames class * {
     native <methods>;

android/app/src/main/AndroidManifest.xml

@@ -4,26 +4,30 @@
     <!-- Permissions -->
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" 
-        android:maxSdkVersion="28" />
+        android:maxSdkVersion="29" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" 
         android:maxSdkVersion="32" />
+    <!-- For Android 11+ (API 30-32) - full storage access -->
+    <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
 
     <application
         android:label="SpotiFLAC"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher"
         android:requestLegacyExternalStorage="true"
-        android:usesCleartextTraffic="true">
+        android:usesCleartextTraffic="true"
+        android:enableOnBackInvokedCallback="true">
 
         <activity
             android:name=".MainActivity"
             android:exported="true"
-            android:launchMode="singleTop"
-            android:taskAffinity=""
+            android:launchMode="singleTask"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
@@ -76,6 +80,17 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+
+        <!-- FileProvider for APK installation -->
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileProvider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
     </application>
 
     <queries>

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

@@ -5,83 +5,227 @@ import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
 import android.app.Service
+import android.content.Context
 import android.content.Intent
 import android.os.Build
 import android.os.IBinder
+import android.os.PowerManager
 import androidx.core.app.NotificationCompat
 
+/**
+ * Foreground service to keep downloads running when app is in background.
+ * This prevents Android from killing the download process or throttling network.
+ * 
+ * Note: Android 15+ (API 35+) has a 6-hour timeout for dataSync foreground services.
+ * The service will be stopped automatically after 6 hours of cumulative runtime in 24 hours.
+ */
 class DownloadService : Service() {
+    
     companion object {
-        const val CHANNEL_ID = "spotiflac_download_channel"
-        const val NOTIFICATION_ID = 1
-        const val ACTION_START = "com.zarz.spotiflac.START_DOWNLOAD"
-        const val ACTION_STOP = "com.zarz.spotiflac.STOP_DOWNLOAD"
+        private const val CHANNEL_ID = "download_channel"
+        private const val NOTIFICATION_ID = 1001
+        private const val WAKELOCK_TAG = "SpotiFLAC:DownloadWakeLock"
+        
+        const val ACTION_START = "com.zarz.spotiflac.action.START_DOWNLOAD"
+        const val ACTION_STOP = "com.zarz.spotiflac.action.STOP_DOWNLOAD"
+        const val ACTION_UPDATE_PROGRESS = "com.zarz.spotiflac.action.UPDATE_PROGRESS"
+        
+        const val EXTRA_TRACK_NAME = "track_name"
+        const val EXTRA_ARTIST_NAME = "artist_name"
+        const val EXTRA_PROGRESS = "progress"
+        const val EXTRA_TOTAL = "total"
+        const val EXTRA_QUEUE_COUNT = "queue_count"
+        
+        private var isRunning = false
+        
+        fun isServiceRunning(): Boolean = isRunning
+        
+        fun start(context: Context, trackName: String = "", artistName: String = "", queueCount: Int = 0) {
+            val intent = Intent(context, DownloadService::class.java).apply {
+                action = ACTION_START
+                putExtra(EXTRA_TRACK_NAME, trackName)
+                putExtra(EXTRA_ARTIST_NAME, artistName)
+                putExtra(EXTRA_QUEUE_COUNT, queueCount)
+            }
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                context.startForegroundService(intent)
+            } else {
+                context.startService(intent)
+            }
+        }
+        
+        fun stop(context: Context) {
+            val intent = Intent(context, DownloadService::class.java).apply {
+                action = ACTION_STOP
+            }
+            context.startService(intent)
+        }
+        
+        fun updateProgress(context: Context, trackName: String, artistName: String, progress: Long, total: Long, queueCount: Int) {
+            val intent = Intent(context, DownloadService::class.java).apply {
+                action = ACTION_UPDATE_PROGRESS
+                putExtra(EXTRA_TRACK_NAME, trackName)
+                putExtra(EXTRA_ARTIST_NAME, artistName)
+                putExtra(EXTRA_PROGRESS, progress)
+                putExtra(EXTRA_TOTAL, total)
+                putExtra(EXTRA_QUEUE_COUNT, queueCount)
+            }
+            context.startService(intent)
+        }
     }
-
+    
+    private var wakeLock: PowerManager.WakeLock? = null
+    private var currentTrackName = ""
+    private var currentArtistName = ""
+    private var queueCount = 0
+    
     override fun onCreate() {
         super.onCreate()
         createNotificationChannel()
     }
-
+    
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
         when (intent?.action) {
-            ACTION_START -> startForegroundService()
-            ACTION_STOP -> stopSelf()
+            ACTION_START -> {
+                currentTrackName = intent.getStringExtra(EXTRA_TRACK_NAME) ?: ""
+                currentArtistName = intent.getStringExtra(EXTRA_ARTIST_NAME) ?: ""
+                queueCount = intent.getIntExtra(EXTRA_QUEUE_COUNT, 0)
+                startForegroundService()
+            }
+            ACTION_STOP -> {
+                stopForegroundService()
+            }
+            ACTION_UPDATE_PROGRESS -> {
+                currentTrackName = intent.getStringExtra(EXTRA_TRACK_NAME) ?: currentTrackName
+                currentArtistName = intent.getStringExtra(EXTRA_ARTIST_NAME) ?: currentArtistName
+                val progress = intent.getLongExtra(EXTRA_PROGRESS, 0)
+                val total = intent.getLongExtra(EXTRA_TOTAL, 0)
+                queueCount = intent.getIntExtra(EXTRA_QUEUE_COUNT, queueCount)
+                updateNotification(progress, total)
+            }
         }
-        return START_NOT_STICKY
+        return START_STICKY
     }
-
+    
     override fun onBind(intent: Intent?): IBinder? = null
-
+    
+    /**
+     * Called when the foreground service timeout is reached (Android 15+, API 35+).
+     * dataSync services have a 6-hour limit in a 24-hour period.
+     * We must call stopSelf() within a few seconds to avoid a crash.
+     */
+    override fun onTimeout(startId: Int, fgsType: Int) {
+        // Log the timeout for debugging
+        android.util.Log.w("DownloadService", "Foreground service timeout reached (6 hours limit). Stopping service.")
+        
+        // Gracefully stop the service
+        stopForegroundService()
+    }
+    
     private fun createNotificationChannel() {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             val channel = NotificationChannel(
                 CHANNEL_ID,
-                "Download Progress",
+                "Download Service",
                 NotificationManager.IMPORTANCE_LOW
             ).apply {
-                description = "Shows download progress for SpotiFLAC"
+                description = "Shows download progress"
                 setShowBadge(false)
             }
             val manager = getSystemService(NotificationManager::class.java)
             manager.createNotificationChannel(channel)
         }
     }
-
+    
     private fun startForegroundService() {
-        val notification = createNotification("Downloading...", 0)
+        isRunning = true
+        
+        // Acquire wake lock to prevent CPU sleep
+        val powerManager = getSystemService(Context.POWER_SERVICE) as PowerManager
+        wakeLock = powerManager.newWakeLock(
+            PowerManager.PARTIAL_WAKE_LOCK,
+            WAKELOCK_TAG
+        ).apply {
+            acquire(60 * 60 * 1000L) // 1 hour max
+        }
+        
+        val notification = buildNotification(0, 0)
         startForeground(NOTIFICATION_ID, notification)
     }
-
-    fun updateProgress(trackName: String, progress: Int) {
-        val notification = createNotification(trackName, progress)
+    
+    private fun stopForegroundService() {
+        isRunning = false
+        wakeLock?.let {
+            if (it.isHeld) {
+                it.release()
+            }
+        }
+        wakeLock = null
+        stopForeground(STOP_FOREGROUND_REMOVE)
+        stopSelf()
+    }
+    
+    private fun updateNotification(progress: Long, total: Long) {
+        if (!isRunning) return
+        
+        val notification = buildNotification(progress, total)
         val manager = getSystemService(NotificationManager::class.java)
         manager.notify(NOTIFICATION_ID, notification)
     }
-
-    private fun createNotification(title: String, progress: Int): Notification {
-        val intent = Intent(this, MainActivity::class.java)
+    
+    private fun buildNotification(progress: Long, total: Long): Notification {
         val pendingIntent = PendingIntent.getActivity(
-            this, 0, intent,
+            this,
+            0,
+            Intent(this, MainActivity::class.java),
             PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
         )
-
-        val stopIntent = Intent(this, DownloadService::class.java).apply {
-            action = ACTION_STOP
+        
+        val title = if (queueCount > 1) {
+            "Downloading $queueCount tracks"
+        } else if (currentTrackName.isNotEmpty()) {
+            currentTrackName
+        } else {
+            "Downloading..."
         }
-        val stopPendingIntent = PendingIntent.getService(
-            this, 0, stopIntent,
-            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
-        )
-
-        return NotificationCompat.Builder(this, CHANNEL_ID)
-            .setContentTitle("SpotiFLAC")
-            .setContentText(title)
+        
+        val text = if (currentArtistName.isNotEmpty() && queueCount <= 1) {
+            currentArtistName
+        } else if (total > 0) {
+            val progressPercent = (progress * 100 / total).toInt()
+            val progressMB = progress / (1024.0 * 1024.0)
+            val totalMB = total / (1024.0 * 1024.0)
+            String.format("%.1f / %.1f MB (%d%%)", progressMB, totalMB, progressPercent)
+        } else {
+            "Preparing download..."
+        }
+        
+        val builder = NotificationCompat.Builder(this, CHANNEL_ID)
+            .setContentTitle(title)
+            .setContentText(text)
             .setSmallIcon(android.R.drawable.stat_sys_download)
-            .setProgress(100, progress, progress == 0)
-            .setOngoing(true)
             .setContentIntent(pendingIntent)
-            .addAction(android.R.drawable.ic_menu_close_clear_cancel, "Cancel", stopPendingIntent)
-            .build()
+            .setOngoing(true)
+            .setOnlyAlertOnce(true)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .setCategory(NotificationCompat.CATEGORY_PROGRESS)
+        
+        if (total > 0) {
+            builder.setProgress(100, (progress * 100 / total).toInt(), false)
+        } else {
+            builder.setProgress(0, 0, true)
+        }
+        
+        return builder.build()
+    }
+    
+    override fun onDestroy() {
+        isRunning = false
+        wakeLock?.let {
+            if (it.isHeld) {
+                it.release()
+            }
+        }
+        super.onDestroy()
     }
 }

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

@@ -1,9 +1,12 @@
 package com.zarz.spotiflac
 
+import android.content.Intent
 import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
 import gobackend.Gobackend
+import com.arthenica.ffmpegkit.FFmpegKit
+import com.arthenica.ffmpegkit.ReturnCode
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -12,8 +15,15 @@ import kotlinx.coroutines.withContext
 
 class MainActivity: FlutterActivity() {
     private val CHANNEL = "com.zarz.spotiflac/backend"
+    private val FFMPEG_CHANNEL = "com.zarz.spotiflac/ffmpeg"
     private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
 
+    override fun onNewIntent(intent: Intent) {
+        super.onNewIntent(intent)
+        // Update the intent so receive_sharing_intent can access the new data
+        setIntent(intent)
+    }
+
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
         
@@ -43,6 +53,15 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "searchSpotifyAll" -> {
+                            val query = call.argument<String>("query") ?: ""
+                            val trackLimit = call.argument<Int>("track_limit") ?: 15
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 3
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchSpotifyAll(query, trackLimit.toLong(), artistLimit.toLong())
+                            }
+                            result.success(response)
+                        }
                         "checkAvailability" -> {
                             val spotifyId = call.argument<String>("spotify_id") ?: ""
                             val isrc = call.argument<String>("isrc") ?: ""
@@ -71,6 +90,33 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "getAllDownloadProgress" -> {
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getAllDownloadProgress()
+                            }
+                            result.success(response)
+                        }
+                        "initItemProgress" -> {
+                            val itemId = call.argument<String>("item_id") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.initItemProgress(itemId)
+                            }
+                            result.success(null)
+                        }
+                        "finishItemProgress" -> {
+                            val itemId = call.argument<String>("item_id") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.finishItemProgress(itemId)
+                            }
+                            result.success(null)
+                        }
+                        "clearItemProgress" -> {
+                            val itemId = call.argument<String>("item_id") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.clearItemProgress(itemId)
+                            }
+                            result.success(null)
+                        }
                         "setDownloadDirectory" -> {
                             val path = call.argument<String>("path") ?: ""
                             withContext(Dispatchers.IO) {
@@ -114,8 +160,9 @@ class MainActivity: FlutterActivity() {
                             val spotifyId = call.argument<String>("spotify_id") ?: ""
                             val trackName = call.argument<String>("track_name") ?: ""
                             val artistName = call.argument<String>("artist_name") ?: ""
+                            val filePath = call.argument<String>("file_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.getLyricsLRC(spotifyId, trackName, artistName)
+                                Gobackend.getLyricsLRC(spotifyId, trackName, artistName, filePath)
                             }
                             result.success(response)
                         }
@@ -133,6 +180,143 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(null)
                         }
+                        "readFileMetadata" -> {
+                            val filePath = call.argument<String>("file_path") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.readFileMetadata(filePath)
+                            }
+                            result.success(response)
+                        }
+                        "startDownloadService" -> {
+                            val trackName = call.argument<String>("track_name") ?: ""
+                            val artistName = call.argument<String>("artist_name") ?: ""
+                            val queueCount = call.argument<Int>("queue_count") ?: 0
+                            DownloadService.start(this@MainActivity, trackName, artistName, queueCount)
+                            result.success(null)
+                        }
+                        "stopDownloadService" -> {
+                            DownloadService.stop(this@MainActivity)
+                            result.success(null)
+                        }
+                        "updateDownloadServiceProgress" -> {
+                            val trackName = call.argument<String>("track_name") ?: ""
+                            val artistName = call.argument<String>("artist_name") ?: ""
+                            val progress = call.argument<Long>("progress") ?: 0L
+                            val total = call.argument<Long>("total") ?: 0L
+                            val queueCount = call.argument<Int>("queue_count") ?: 0
+                            DownloadService.updateProgress(this@MainActivity, trackName, artistName, progress, total, queueCount)
+                            result.success(null)
+                        }
+                        "isDownloadServiceRunning" -> {
+                            result.success(DownloadService.isServiceRunning())
+                        }
+                        "setSpotifyCredentials" -> {
+                            val clientId = call.argument<String>("client_id") ?: ""
+                            val clientSecret = call.argument<String>("client_secret") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.setSpotifyAPICredentials(clientId, clientSecret)
+                            }
+                            result.success(null)
+                        }
+                        "preWarmTrackCache" -> {
+                            val tracksJson = call.argument<String>("tracks") ?: "[]"
+                            withContext(Dispatchers.IO) {
+                                Gobackend.preWarmTrackCacheJSON(tracksJson)
+                            }
+                            result.success(null)
+                        }
+                        "getTrackCacheSize" -> {
+                            val size = withContext(Dispatchers.IO) {
+                                Gobackend.getTrackCacheSize()
+                            }
+                            result.success(size.toInt())
+                        }
+                        "clearTrackCache" -> {
+                            withContext(Dispatchers.IO) {
+                                Gobackend.clearTrackIDCache()
+                            }
+                            result.success(null)
+                        }
+                        // Deezer API methods
+                        "searchDeezerAll" -> {
+                            val query = call.argument<String>("query") ?: ""
+                            val trackLimit = call.argument<Int>("track_limit") ?: 15
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 3
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchDeezerAll(query, trackLimit.toLong(), artistLimit.toLong())
+                            }
+                            result.success(response)
+                        }
+                        "getDeezerMetadata" -> {
+                            val resourceType = call.argument<String>("resource_type") ?: ""
+                            val resourceId = call.argument<String>("resource_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getDeezerMetadata(resourceType, resourceId)
+                            }
+                            result.success(response)
+                        }
+                        "parseDeezerUrl" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.parseDeezerURLExport(url)
+                            }
+                            result.success(response)
+                        }
+                        "searchDeezerByISRC" -> {
+                            val isrc = call.argument<String>("isrc") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.searchDeezerByISRC(isrc)
+                            }
+                            result.success(response)
+                        }
+                        "convertSpotifyToDeezer" -> {
+                            val resourceType = call.argument<String>("resource_type") ?: ""
+                            val spotifyId = call.argument<String>("spotify_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.convertSpotifyToDeezer(resourceType, spotifyId)
+                            }
+                            result.success(response)
+                        }
+                        "getSpotifyMetadataWithFallback" -> {
+                            val url = call.argument<String>("url") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getSpotifyMetadataWithDeezerFallback(url)
+                            }
+                            result.success(response)
+                        }
+                        // Log methods
+                        "getLogs" -> {
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getLogs()
+                            }
+                            result.success(response)
+                        }
+                        "getLogsSince" -> {
+                            val index = call.argument<Int>("index") ?: 0
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getLogsSince(index.toLong())
+                            }
+                            result.success(response)
+                        }
+                        "clearLogs" -> {
+                            withContext(Dispatchers.IO) {
+                                Gobackend.clearLogs()
+                            }
+                            result.success(null)
+                        }
+                        "getLogCount" -> {
+                            val count = withContext(Dispatchers.IO) {
+                                Gobackend.getLogCount()
+                            }
+                            result.success(count.toInt())
+                        }
+                        "setLoggingEnabled" -> {
+                            val enabled = call.argument<Boolean>("enabled") ?: false
+                            withContext(Dispatchers.IO) {
+                                Gobackend.setLoggingEnabled(enabled)
+                            }
+                            result.success(null)
+                        }
                         else -> result.notImplemented()
                     }
                 } catch (e: Exception) {
@@ -140,5 +324,37 @@ class MainActivity: FlutterActivity() {
                 }
             }
         }
+        
+        // FFmpeg method channel
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, FFMPEG_CHANNEL).setMethodCallHandler { call, result ->
+            scope.launch {
+                try {
+                    when (call.method) {
+                        "execute" -> {
+                            val command = call.argument<String>("command") ?: ""
+                            val session = withContext(Dispatchers.IO) {
+                                FFmpegKit.execute(command)
+                            }
+                            val returnCode = session.returnCode
+                            val output = session.output ?: ""
+                            result.success(mapOf(
+                                "success" to ReturnCode.isSuccess(returnCode),
+                                "returnCode" to (returnCode?.value ?: -1),
+                                "output" to output
+                            ))
+                        }
+                        "getVersion" -> {
+                            val session = withContext(Dispatchers.IO) {
+                                FFmpegKit.execute("-version")
+                            }
+                            result.success(session.output ?: "unknown")
+                        }
+                        else -> result.notImplemented()
+                    }
+                } catch (e: Exception) {
+                    result.error("FFMPEG_ERROR", e.message, null)
+                }
+            }
+        }
     }
 }

android/app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <external-files-path name="external_files" path="." />
+    <cache-path name="cache" path="." />
+    <files-path name="files" path="." />
+</paths>

android/build.gradle.kts

@@ -10,10 +10,19 @@ subprojects {
         if (project.hasProperty("android")) {
             project.extensions.configure<com.android.build.gradle.BaseExtension>("android") {
                 compileOptions {
+                    isCoreLibraryDesugaringEnabled = true
                     sourceCompatibility = JavaVersion.VERSION_17
                     targetCompatibility = JavaVersion.VERSION_17
                 }
+                
+                // Enable multidex for all subprojects
+                defaultConfig {
+                    multiDexEnabled = true
+                }
             }
+            
+            // Add desugaring dependency to all Android subprojects
+            project.dependencies.add("coreLibraryDesugaring", "com.android.tools:desugar_jdk_libs:2.1.4")
         }
         
         tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {

android/settings.gradle.kts

@@ -20,7 +20,7 @@ pluginManagement {
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.11.1" apply false
-    id("org.jetbrains.kotlin.android") version "2.2.20" apply false
+    id("org.jetbrains.kotlin.android") version "2.3.0" apply false
 }
 
 include(":app")

build_assets/ffmpeg_service_ios.dart

@@ -0,0 +1,208 @@
+import 'dart:io';
+import 'package:ffmpeg_kit_flutter_new_audio/ffmpeg_kit.dart';
+import 'package:ffmpeg_kit_flutter_new_audio/return_code.dart';
+import 'package:spotiflac_android/utils/logger.dart';
+
+final _log = AppLogger('FFmpeg');
+
+/// FFmpeg service for iOS using ffmpeg_kit_flutter plugin
+class FFmpegServiceIOS {
+  /// Execute FFmpeg command and return result
+  static Future<FFmpegResultIOS> _execute(String command) async {
+    try {
+      final session = await FFmpegKit.execute(command);
+      final returnCode = await session.getReturnCode();
+      final output = await session.getOutput() ?? '';
+      return FFmpegResultIOS(
+        success: ReturnCode.isSuccess(returnCode),
+        returnCode: returnCode?.getValue() ?? -1,
+        output: output,
+      );
+    } catch (e) {
+      _log.e('FFmpeg execute error: $e');
+      return FFmpegResultIOS(success: false, returnCode: -1, output: e.toString());
+    }
+  }
+
+  /// Convert M4A (DASH segments) to FLAC
+  static Future<String?> convertM4aToFlac(String inputPath) async {
+    final outputPath = inputPath.replaceAll('.m4a', '.flac');
+    final command = '-i "$inputPath" -c:a flac -compression_level 8 "$outputPath" -y';
+    final result = await _execute(command);
+
+    if (result.success) {
+      try {
+        await File(inputPath).delete();
+      } catch (_) {}
+      return outputPath;
+    }
+
+    _log.e('M4A to FLAC conversion failed: ${result.output}');
+    return null;
+  }
+
+  /// Convert FLAC to MP3
+  static Future<String?> convertFlacToMp3(String inputPath, {String bitrate = '320k'}) async {
+    final dir = File(inputPath).parent.path;
+    final baseName = inputPath.split(Platform.pathSeparator).last.replaceAll('.flac', '');
+    final outputDir = '$dir${Platform.pathSeparator}MP3';
+    await Directory(outputDir).create(recursive: true);
+    final outputPath = '$outputDir${Platform.pathSeparator}$baseName.mp3';
+
+    final command = '-i "$inputPath" -codec:a libmp3lame -b:a $bitrate -map 0:a -map_metadata 0 -id3v2_version 3 "$outputPath" -y';
+    final result = await _execute(command);
+
+    if (result.success) return outputPath;
+    _log.e('FLAC to MP3 conversion failed: ${result.output}');
+    return null;
+  }
+
+  /// Convert FLAC to M4A
+  static Future<String?> convertFlacToM4a(String inputPath, {String codec = 'aac', String bitrate = '256k'}) async {
+    final dir = File(inputPath).parent.path;
+    final baseName = inputPath.split(Platform.pathSeparator).last.replaceAll('.flac', '');
+    final outputDir = '$dir${Platform.pathSeparator}M4A';
+    await Directory(outputDir).create(recursive: true);
+    final outputPath = '$outputDir${Platform.pathSeparator}$baseName.m4a';
+
+    String command;
+    if (codec == 'alac') {
+      command = '-i "$inputPath" -codec:a alac -map 0:a -map_metadata 0 "$outputPath" -y';
+    } else {
+      command = '-i "$inputPath" -codec:a aac -b:a $bitrate -map 0:a -map_metadata 0 "$outputPath" -y';
+    }
+
+    final result = await _execute(command);
+    if (result.success) return outputPath;
+    _log.e('FLAC to M4A conversion failed: ${result.output}');
+    return null;
+  }
+
+  /// Embed cover art to FLAC file
+  static Future<String?> embedCover(String flacPath, String coverPath) async {
+    final tempOutput = '$flacPath.tmp';
+    final command = '-i "$flacPath" -i "$coverPath" -map 0:a -map 1:0 -c copy -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (front)" -disposition:v attached_pic "$tempOutput" -y';
+
+    final result = await _execute(command);
+
+    if (result.success) {
+      try {
+        await File(flacPath).delete();
+        await File(tempOutput).rename(flacPath);
+        return flacPath;
+      } catch (e) {
+        _log.e('Failed to replace file after cover embed: $e');
+        return null;
+      }
+    }
+
+    try {
+      final tempFile = File(tempOutput);
+      if (await tempFile.exists()) await tempFile.delete();
+    } catch (_) {}
+
+    _log.e('Cover embed failed: ${result.output}');
+    return null;
+  }
+
+  /// Embed metadata and cover art to FLAC file
+  /// Returns the file path on success, null on failure
+  static Future<String?> embedMetadata({
+    required String flacPath,
+    String? coverPath,
+    Map<String, String>? metadata,
+  }) async {
+    final tempOutput = '$flacPath.tmp';
+    
+    // Construct command
+    final StringBuffer cmdBuffer = StringBuffer();
+    cmdBuffer.write('-i "$flacPath" ');
+    
+    // Add cover input if available
+    if (coverPath != null) {
+      cmdBuffer.write('-i "$coverPath" ');
+    }
+    
+    // Map audio stream
+    cmdBuffer.write('-map 0:a ');
+    
+    // Map cover stream if available
+    if (coverPath != null) {
+      cmdBuffer.write('-map 1:0 ');
+      cmdBuffer.write('-c:v copy ');
+      cmdBuffer.write('-disposition:v attached_pic ');
+      cmdBuffer.write('-metadata:s:v title="Album cover" ');
+      cmdBuffer.write('-metadata:s:v comment="Cover (front)" ');
+    }
+    
+    // Copy audio codec (don't re-encode)
+    cmdBuffer.write('-c:a copy ');
+    
+    // Add text metadata
+    if (metadata != null) {
+      metadata.forEach((key, value) {
+        // Sanitize value: escape double quotes
+        final sanitizedValue = value.replaceAll('"', '\\"');
+        cmdBuffer.write('-metadata $key="$sanitizedValue" ');
+      });
+    }
+    
+    cmdBuffer.write('"$tempOutput" -y');
+    
+    final command = cmdBuffer.toString();
+    _log.d('Executing FFmpeg command: $command');
+
+    final result = await _execute(command);
+
+    if (result.success) {
+      try {
+        await File(flacPath).delete();
+        await File(tempOutput).rename(flacPath);
+        return flacPath;
+      } catch (e) {
+        _log.e('Failed to replace file after metadata embed: $e');
+        return null;
+      }
+    }
+
+    // Clean up temp file if exists
+    try {
+      final tempFile = File(tempOutput);
+      if (await tempFile.exists()) {
+        await tempFile.delete();
+      }
+    } catch (_) {}
+
+    _log.e('Metadata/Cover embed failed: ${result.output}');
+    return null;
+  }
+
+  /// Check if FFmpeg is available
+  static Future<bool> isAvailable() async {
+    try {
+      final session = await FFmpegKit.execute('-version');
+      final returnCode = await session.getReturnCode();
+      return ReturnCode.isSuccess(returnCode);
+    } catch (e) {
+      return false;
+    }
+  }
+
+  /// Get FFmpeg version info
+  static Future<String?> getVersion() async {
+    try {
+      final session = await FFmpegKit.execute('-version');
+      return await session.getOutput();
+    } catch (e) {
+      return null;
+    }
+  }
+}
+
+class FFmpegResultIOS {
+  final bool success;
+  final int returnCode;
+  final String output;
+
+  FFmpegResultIOS({required this.success, required this.returnCode, required this.output});
+}

devtools_options.yaml

@@ -0,0 +1,3 @@
+description: This file stores settings for Dart & Flutter DevTools.
+documentation: https://docs.flutter.dev/tools/devtools/extensions#configure-extension-enablement-states
+extensions:

go_backend/amazon.go

@@ -1,6 +1,7 @@
 package gobackend
 
 import (
+	"bufio"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@@ -10,15 +11,26 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"time"
 )
 
 // AmazonDownloader handles Amazon Music downloads using DoubleDouble service (same as PC)
 type AmazonDownloader struct {
-	client  *http.Client
-	regions []string // us, eu regions for DoubleDouble service
+	client           *http.Client
+	regions          []string  // us, eu regions for DoubleDouble service
+	lastAPICallTime  time.Time // Rate limiting: track last API call
+	apiCallCount     int       // Rate limiting: counter per minute
+	apiCallResetTime time.Time // Rate limiting: reset time
 }
 
+var (
+	// Global Amazon downloader instance for connection reuse
+	globalAmazonDownloader *AmazonDownloader
+	amazonDownloaderOnce   sync.Once
+	amazonRateLimitMu      sync.Mutex // Mutex for rate limiting
+)
+
 // DoubleDoubleSubmitResponse is the response from DoubleDouble submit endpoint
 type DoubleDoubleSubmitResponse struct {
 	Success bool   `json:"success"`
@@ -36,12 +48,114 @@ type DoubleDoubleStatusResponse struct {
 	} `json:"current"`
 }
 
-// NewAmazonDownloader creates a new Amazon downloader using DoubleDouble service
-func NewAmazonDownloader() *AmazonDownloader {
-	return &AmazonDownloader{
-		client:  NewHTTPClientWithTimeout(120 * time.Second), // 120s timeout like PC
-		regions: []string{"us", "eu"},                        // Same regions as PC
+// amazonArtistsMatch checks if the artist names are similar enough
+func amazonArtistsMatch(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
+	}
+
+	// Check first artist (before comma or feat)
+	expectedFirst := strings.Split(normExpected, ",")[0]
+	expectedFirst = strings.Split(expectedFirst, " feat")[0]
+	expectedFirst = strings.Split(expectedFirst, " ft.")[0]
+	expectedFirst = strings.TrimSpace(expectedFirst)
+
+	foundFirst := strings.Split(normFound, ",")[0]
+	foundFirst = strings.Split(foundFirst, " feat")[0]
+	foundFirst = strings.Split(foundFirst, " ft.")[0]
+	foundFirst = strings.TrimSpace(foundFirst)
+
+	if expectedFirst == foundFirst {
+		return true
+	}
+
+	// Check if first artist is contained in the other
+	if strings.Contains(expectedFirst, foundFirst) || strings.Contains(foundFirst, expectedFirst) {
+		return true
+	}
+
+	// If scripts are different (one is ASCII, one is non-ASCII like Japanese/Chinese/Korean),
+	// assume they're the same artist with different transliteration
+	expectedASCII := amazonIsASCIIString(expectedArtist)
+	foundASCII := amazonIsASCIIString(foundArtist)
+	if expectedASCII != foundASCII {
+		GoLog("[Amazon] Artist names in different scripts, assuming match: '%s' vs '%s'\n", expectedArtist, foundArtist)
+		return true
+	}
+
+	return false
+}
+
+// amazonIsASCIIString checks if a string contains only ASCII characters
+func amazonIsASCIIString(s string) bool {
+	for _, r := range s {
+		if r > 127 {
+			return false
+		}
+	}
+	return true
+}
+
+// NewAmazonDownloader creates a new Amazon downloader (returns singleton for connection reuse)
+func NewAmazonDownloader() *AmazonDownloader {
+	amazonDownloaderOnce.Do(func() {
+		globalAmazonDownloader = &AmazonDownloader{
+			client:           NewHTTPClientWithTimeout(120 * time.Second), // 120s timeout like PC
+			regions:          []string{"us", "eu"},                        // Same regions as PC
+			apiCallResetTime: time.Now(),
+		}
+	})
+	return globalAmazonDownloader
+}
+
+// waitForRateLimit implements rate limiting similar to PC version
+// Max 9 requests per minute with 7 second delay between requests
+func (a *AmazonDownloader) waitForRateLimit() {
+	amazonRateLimitMu.Lock()
+	defer amazonRateLimitMu.Unlock()
+
+	now := time.Now()
+
+	// Reset counter every minute
+	if now.Sub(a.apiCallResetTime) >= time.Minute {
+		a.apiCallCount = 0
+		a.apiCallResetTime = now
+	}
+
+	// If we've hit the limit (9 requests per minute), wait until next minute
+	if a.apiCallCount >= 9 {
+		waitTime := time.Minute - now.Sub(a.apiCallResetTime)
+		if waitTime > 0 {
+			GoLog("[Amazon] Rate limit reached, waiting %v...\n", waitTime.Round(time.Second))
+			time.Sleep(waitTime)
+			a.apiCallCount = 0
+			a.apiCallResetTime = time.Now()
+		}
+	}
+
+	// Add delay between requests (7 seconds like PC version)
+	if !a.lastAPICallTime.IsZero() {
+		timeSinceLastCall := now.Sub(a.lastAPICallTime)
+		minDelay := 7 * time.Second
+		if timeSinceLastCall < minDelay {
+			waitTime := minDelay - timeSinceLastCall
+			GoLog("[Amazon] Rate limiting: waiting %v...\n", waitTime.Round(time.Second))
+			time.Sleep(waitTime)
+		}
+	}
+
+	// Update tracking
+	a.lastAPICallTime = time.Now()
+	a.apiCallCount++
 }
 
 // GetAvailableAPIs returns list of available DoubleDouble regions
@@ -56,7 +170,6 @@ func (a *AmazonDownloader) GetAvailableAPIs() []string {
 	return apis
 }
 
-
 // downloadFromDoubleDoubleService downloads a track using DoubleDouble service (same as PC)
 // This uses submit → poll → download mechanism
 // Internal function - not exported to gomobile
@@ -64,18 +177,21 @@ func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, outputDir
 	var lastError error
 
 	for _, region := range a.regions {
-		fmt.Printf("[Amazon] Trying region: %s...\n", region)
+		GoLog("[Amazon] Trying region: %s...\n", region)
 
 		// Build base URL for DoubleDouble service
 		// Decode base64 service URL (same as PC)
-		serviceBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly8=")         // https://
+		serviceBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly8=")               // https://
 		serviceDomain, _ := base64.StdEncoding.DecodeString("LmRvdWJsZWRvdWJsZS50b3A=") // .doubledouble.top
 		baseURL := fmt.Sprintf("%s%s%s", string(serviceBase), region, string(serviceDomain))
 
-		// Step 1: Submit download request
+		// Step 1: Submit download request with rate limiting
 		encodedURL := url.QueryEscape(amazonURL)
 		submitURL := fmt.Sprintf("%s/dl?url=%s", baseURL, encodedURL)
 
+		// Apply rate limiting before request (like PC version)
+		a.waitForRateLimit()
+
 		req, err := http.NewRequest("GET", submitURL, nil)
 		if err != nil {
 			lastError = fmt.Errorf("failed to create request: %w", err)
@@ -85,15 +201,43 @@ func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, outputDir
 		req.Header.Set("User-Agent", getRandomUserAgent())
 
 		fmt.Println("[Amazon] Submitting download request...")
-		resp, err := a.client.Do(req)
-		if err != nil {
-			lastError = fmt.Errorf("failed to submit request: %w", err)
-			continue
+
+		// Retry logic for 429 errors (like PC version: 3 retries with 15s wait)
+		var resp *http.Response
+		maxRetries := 3
+		for retry := 0; retry < maxRetries; retry++ {
+			resp, err = a.client.Do(req)
+			if err != nil {
+				lastError = fmt.Errorf("failed to submit request: %w", err)
+				break
+			}
+
+			if resp.StatusCode == 429 { // Too Many Requests
+				resp.Body.Close()
+				if retry < maxRetries-1 {
+					waitTime := 15 * time.Second
+					GoLog("[Amazon] Rate limited (429), waiting %v before retry %d/%d...\n", waitTime, retry+2, maxRetries)
+					time.Sleep(waitTime)
+					continue
+				}
+				lastError = fmt.Errorf("API rate limit exceeded after %d retries", maxRetries)
+				break
+			}
+
+			if resp.StatusCode != 200 {
+				resp.Body.Close()
+				lastError = fmt.Errorf("submit failed with status %d", resp.StatusCode)
+				break
+			}
+
+			// Success - break retry loop
+			break
 		}
 
-		if resp.StatusCode != 200 {
-			resp.Body.Close()
-			lastError = fmt.Errorf("submit failed with status %d", resp.StatusCode)
+		if err != nil || lastError != nil {
+			if resp != nil {
+				resp.Body.Close()
+			}
 			continue
 		}
 
@@ -111,7 +255,7 @@ func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, outputDir
 		}
 
 		downloadID := submitResp.ID
-		fmt.Printf("[Amazon] Download ID: %s\n", downloadID)
+		GoLog("[Amazon] Download ID: %s\n", downloadID)
 
 		// Step 2: Poll for completion
 		statusURL := fmt.Sprintf("%s/dl/%s", baseURL, downloadID)
@@ -166,7 +310,7 @@ func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, outputDir
 				trackName := status.Current.Name
 				artist := status.Current.Artist
 
-				fmt.Printf("[Amazon] Downloading: %s - %s\n", artist, trackName)
+				GoLog("[Amazon] Downloading: %s - %s\n", artist, trackName)
 				return fileURL, trackName, artist, nil
 
 			} else if status.Status == "error" {
@@ -200,13 +344,13 @@ func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, outputDir
 	return "", "", "", fmt.Errorf("all regions failed. Last error: %v", lastError)
 }
 
-
 // DownloadFile downloads a file from URL with User-Agent and progress tracking
-func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath string) error {
-	// Set current file being downloaded
-	SetCurrentFile(filepath.Base(outputPath))
-	SetDownloading(true)
-	defer SetDownloading(false)
+func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
+	// Initialize item progress (required for all downloads)
+	if itemID != "" {
+		StartItemProgress(itemID)
+		defer CompleteItemProgress(itemID)
+	}
 
 	req, err := http.NewRequest("GET", downloadURL, nil)
 	if err != nil {
@@ -225,62 +369,130 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath string) error {
 		return fmt.Errorf("download failed: HTTP %d", resp.StatusCode)
 	}
 
+	expectedSize := resp.ContentLength
 	// Set total bytes if available
-	if resp.ContentLength > 0 {
-		SetBytesTotal(resp.ContentLength)
+	if expectedSize > 0 && itemID != "" {
+		SetItemBytesTotal(itemID, expectedSize)
 	}
 
 	out, err := os.Create(outputPath)
 	if err != nil {
 		return err
 	}
-	defer out.Close()
 
-	// Track download progress
-	pw := NewProgressWriter(out)
-	_, err = io.Copy(pw, resp.Body)
-	if err != nil {
-		return fmt.Errorf("failed to write file: %w", err)
+	// Use buffered writer for better performance (256KB buffer)
+	bufWriter := bufio.NewWriterSize(out, 256*1024)
+
+	// Use item progress writer with buffered output
+	var written int64
+	if itemID != "" {
+		pw := NewItemProgressWriter(bufWriter, itemID)
+		written, err = io.Copy(pw, resp.Body)
+	} else {
+		// Fallback: direct copy without progress tracking
+		written, err = io.Copy(bufWriter, resp.Body)
 	}
 
-	fmt.Printf("\r[Amazon] Downloaded: %.2f MB (Complete)\n", float64(pw.GetTotal())/(1024*1024))
+	// Flush buffer before checking for errors
+	flushErr := bufWriter.Flush()
+	closeErr := out.Close()
+
+	// Check for any errors
+	if err != nil {
+		os.Remove(outputPath)
+		return fmt.Errorf("download interrupted: %w", err)
+	}
+	if flushErr != nil {
+		os.Remove(outputPath)
+		return fmt.Errorf("failed to flush buffer: %w", flushErr)
+	}
+	if closeErr != nil {
+		os.Remove(outputPath)
+		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)
+	}
+
+	fmt.Printf("\r[Amazon] Downloaded: %.2f MB (Complete)\n", float64(written)/(1024*1024))
 	return nil
 }
 
+// AmazonDownloadResult contains download result with quality info
+type AmazonDownloadResult struct {
+	FilePath    string
+	BitDepth    int
+	SampleRate  int
+	Title       string
+	Artist      string
+	Album       string
+	ReleaseDate string
+	TrackNumber int
+	DiscNumber  int
+	ISRC        string
+}
+
 // downloadFromAmazon downloads a track using the request parameters
 // Uses DoubleDouble service (same as PC version)
-func downloadFromAmazon(req DownloadRequest) (string, error) {
+func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	downloader := NewAmazonDownloader()
 
 	// Check for existing file first
 	if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
-		return "EXISTS:" + existingFile, nil
+		return AmazonDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
 	// Get Amazon URL from SongLink
 	songlink := NewSongLinkClient()
-	availability, err := songlink.CheckTrackAvailability(req.SpotifyID, req.ISRC)
+	var availability *TrackAvailability
+	var err error
+
+	// Check if SpotifyID is actually a Deezer ID (format: "deezer:xxxxx")
+	if strings.HasPrefix(req.SpotifyID, "deezer:") {
+		// Extract Deezer ID and use Deezer-based lookup
+		deezerID := strings.TrimPrefix(req.SpotifyID, "deezer:")
+		GoLog("[Amazon] Using Deezer ID for SongLink lookup: %s\n", deezerID)
+		availability, err = songlink.CheckAvailabilityFromDeezer(deezerID)
+	} else if req.SpotifyID != "" {
+		// Use Spotify ID
+		availability, err = songlink.CheckTrackAvailability(req.SpotifyID, req.ISRC)
+	} else {
+		return AmazonDownloadResult{}, fmt.Errorf("no valid Spotify or Deezer ID provided for Amazon lookup")
+	}
+
 	if err != nil {
-		return "", fmt.Errorf("failed to check Amazon availability via SongLink: %w", err)
+		return AmazonDownloadResult{}, fmt.Errorf("failed to check Amazon availability via SongLink: %w", err)
 	}
 
 	if !availability.Amazon || availability.AmazonURL == "" {
-		return "", fmt.Errorf("track not available on Amazon Music (SongLink returned no Amazon URL)")
+		return AmazonDownloadResult{}, fmt.Errorf("track not available on Amazon Music (SongLink returned no Amazon URL)")
 	}
 
 	// Create output directory if needed
 	if req.OutputDir != "." {
 		if err := os.MkdirAll(req.OutputDir, 0755); err != nil {
-			return "", fmt.Errorf("failed to create output directory: %w", err)
+			return AmazonDownloadResult{}, fmt.Errorf("failed to create output directory: %w", err)
 		}
 	}
 
 	// Download using DoubleDouble service (same as PC)
 	downloadURL, trackName, artistName, err := downloader.downloadFromDoubleDoubleService(availability.AmazonURL, req.OutputDir)
 	if err != nil {
-		return "", fmt.Errorf("failed to get download URL: %w", err)
+		return AmazonDownloadResult{}, fmt.Errorf("failed to get download URL: %w", err)
 	}
 
+	// Verify artist matches
+	if artistName != "" && !amazonArtistsMatch(req.ArtistName, artistName) {
+		GoLog("[Amazon] Artist mismatch: expected '%s', got '%s'. Rejecting.\n", req.ArtistName, artistName)
+		return AmazonDownloadResult{}, fmt.Errorf("artist mismatch: expected '%s', got '%s'", req.ArtistName, artistName)
+	}
+
+	// Log match found
+	GoLog("[Amazon] Match found: '%s' by '%s'\n", trackName, artistName)
+
 	// Build filename using Spotify metadata (more accurate)
 	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
 		"title":  req.TrackName,
@@ -295,69 +507,144 @@ func downloadFromAmazon(req DownloadRequest) (string, error) {
 
 	// Check if file already exists
 	if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
-		return "EXISTS:" + outputPath, nil
+		return AmazonDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
 
-	// Download file
-	if err := downloader.DownloadFile(downloadURL, outputPath); err != nil {
-		return "", fmt.Errorf("download failed: %w", err)
+	// START PARALLEL: Fetch cover and lyrics while downloading audio
+	var parallelResult *ParallelDownloadResult
+	parallelDone := make(chan struct{})
+	go func() {
+		defer close(parallelDone)
+		parallelResult = FetchCoverAndLyricsParallel(
+			req.CoverURL,
+			req.EmbedMaxQualityCover,
+			req.SpotifyID,
+			req.TrackName,
+			req.ArtistName,
+			req.EmbedLyrics,
+		)
+	}()
+
+	// Download audio file with item ID for progress tracking
+	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+		return AmazonDownloadResult{}, fmt.Errorf("download failed: %w", err)
+	}
+
+	// Wait for parallel operations to complete
+	<-parallelDone
+
+	// Set progress to 100% and status to finalizing (before embedding)
+	// This makes the UI show "Finalizing..." while embedding happens
+	if req.ItemID != "" {
+		SetItemProgress(req.ItemID, 1.0, 0, 0)
+		SetItemFinalizing(req.ItemID)
 	}
 
 	// Log track info from DoubleDouble (for debugging)
 	if trackName != "" && artistName != "" {
-		fmt.Printf("[Amazon] DoubleDouble returned: %s - %s\n", artistName, trackName)
+		GoLog("[Amazon] DoubleDouble returned: %s - %s\n", artistName, trackName)
+	}
+
+	// Read existing metadata from downloaded file BEFORE embedding
+	// Amazon/DoubleDouble files often have correct track/disc numbers that we should preserve
+	existingMeta, metaErr := ReadMetadata(outputPath)
+	actualTrackNum := req.TrackNumber
+	actualDiscNum := req.DiscNumber
+
+	if metaErr == nil && existingMeta != nil {
+		// Use file metadata if it has valid track/disc numbers and request doesn't have them
+		if existingMeta.TrackNumber > 0 && (req.TrackNumber == 0 || req.TrackNumber == 1) {
+			actualTrackNum = existingMeta.TrackNumber
+			GoLog("[Amazon] Using track number from file: %d (request had: %d)\n", actualTrackNum, req.TrackNumber)
+		}
+		if existingMeta.DiscNumber > 0 && (req.DiscNumber == 0 || req.DiscNumber == 1) {
+			actualDiscNum = existingMeta.DiscNumber
+			GoLog("[Amazon] Using disc number from file: %d (request had: %d)\n", actualDiscNum, req.DiscNumber)
+		}
 	}
 
 	// Embed metadata using Spotify data (more accurate than DoubleDouble)
+	// But preserve track/disc numbers from file if they were better
 	metadata := Metadata{
 		Title:       req.TrackName,
 		Artist:      req.ArtistName,
 		Album:       req.AlbumName,
 		AlbumArtist: req.AlbumArtist,
 		Date:        req.ReleaseDate,
-		TrackNumber: req.TrackNumber,
+		TrackNumber: actualTrackNum,
 		TotalTracks: req.TotalTracks,
-		DiscNumber:  req.DiscNumber,
+		DiscNumber:  actualDiscNum,
 		ISRC:        req.ISRC,
 	}
 
-	// Download cover to memory (avoids file permission issues on Android)
+	// Use cover data from parallel fetch
 	var coverData []byte
-	if req.CoverURL != "" {
-		fmt.Println("[Amazon] Downloading cover to memory...")
-		data, err := downloadCoverToMemory(req.CoverURL, req.EmbedMaxQualityCover)
-		if err == nil {
-			coverData = data
-			fmt.Printf("[Amazon] Cover downloaded successfully (%d bytes)\n", len(coverData))
-		} else {
-			fmt.Printf("[Amazon] Warning: failed to download cover: %v\n", err)
-		}
+	if parallelResult != nil && parallelResult.CoverData != nil {
+		coverData = parallelResult.CoverData
+		GoLog("[Amazon] Using parallel-fetched cover (%d bytes)\n", len(coverData))
 	}
 
 	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
 		fmt.Printf("Warning: failed to embed metadata: %v\n", err)
 	}
 
-	// Embed lyrics if enabled
-	if req.EmbedLyrics {
-		fmt.Println("[Amazon] Fetching lyrics...")
-		lyricsClient := NewLyricsClient()
-		lyrics, lyricsErr := lyricsClient.FetchLyricsAllSources(req.SpotifyID, req.TrackName, req.ArtistName)
-		if lyricsErr != nil {
-			fmt.Printf("[Amazon] Warning: lyrics fetch error: %v\n", lyricsErr)
-		} else if lyrics == nil || len(lyrics.Lines) == 0 {
-			fmt.Println("[Amazon] No lyrics found for this track")
+	// Embed lyrics from parallel fetch
+	if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+		GoLog("[Amazon] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
+		if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+			GoLog("[Amazon] Warning: failed to embed lyrics: %v\n", embedErr)
 		} else {
-			fmt.Printf("[Amazon] Lyrics found (%d lines), embedding...\n", len(lyrics.Lines))
-			lrcContent := convertToLRC(lyrics)
-			if embedErr := EmbedLyrics(outputPath, lrcContent); embedErr != nil {
-				fmt.Printf("[Amazon] Warning: failed to embed lyrics: %v\n", embedErr)
-			} else {
-				fmt.Println("[Amazon] Lyrics embedded successfully")
-			}
+			fmt.Println("[Amazon] Lyrics embedded successfully")
 		}
+	} else if req.EmbedLyrics {
+		fmt.Println("[Amazon] No lyrics available from parallel fetch")
 	}
 
 	fmt.Println("[Amazon] ✓ Downloaded successfully from Amazon Music")
-	return outputPath, nil
+
+	// Read actual quality from the downloaded FLAC file
+	// Amazon API doesn't provide quality info, but we can read it from the file itself
+	quality, err := GetAudioQuality(outputPath)
+	if err != nil {
+		GoLog("[Amazon] Warning: couldn't read quality from file: %v\n", err)
+	} else {
+		GoLog("[Amazon] Actual quality: %d-bit/%dHz\n", quality.BitDepth, quality.SampleRate)
+	}
+
+	// Read metadata from file AFTER embedding to get accurate values
+	// This ensures we return what's actually in the file
+	finalMeta, metaReadErr := ReadMetadata(outputPath)
+	if metaReadErr == nil && finalMeta != nil {
+		GoLog("[Amazon] Final metadata from file - Track: %d, Disc: %d, Date: %s\n",
+			finalMeta.TrackNumber, finalMeta.DiscNumber, finalMeta.Date)
+		actualTrackNum = finalMeta.TrackNumber
+		actualDiscNum = finalMeta.DiscNumber
+		if finalMeta.Date != "" {
+			// Use date from file if available
+			req.ReleaseDate = finalMeta.Date
+		}
+	}
+
+	// Add to ISRC index for fast duplicate checking
+	AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
+
+	bitDepth := 0
+	sampleRate := 0
+	if err == nil {
+		bitDepth = quality.BitDepth
+		sampleRate = quality.SampleRate
+	}
+
+	return AmazonDownloadResult{
+		FilePath:    outputPath,
+		BitDepth:    bitDepth,
+		SampleRate:  sampleRate,
+		Title:       req.TrackName,
+		Artist:      req.ArtistName,
+		Album:       req.AlbumName,
+		ReleaseDate: req.ReleaseDate,
+		TrackNumber: actualTrackNum,
+		DiscNumber:  actualDiscNum,
+		ISRC:        req.ISRC,
+	}, nil
 }

go_backend/deezer.go

@@ -0,0 +1,742 @@
+package gobackend
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	deezerBaseURL     = "https://api.deezer.com/2.0"
+	deezerSearchURL   = deezerBaseURL + "/search"
+	deezerTrackURL    = deezerBaseURL + "/track/%s"
+	deezerAlbumURL    = deezerBaseURL + "/album/%s"
+	deezerArtistURL   = deezerBaseURL + "/artist/%s"
+	deezerPlaylistURL = deezerBaseURL + "/playlist/%s"
+
+	deezerCacheTTL = 10 * time.Minute
+
+	// Parallel ISRC fetching settings
+	deezerMaxParallelISRC = 10 // Max concurrent ISRC fetches
+)
+
+// DeezerClient handles Deezer API interactions (no auth required)
+type DeezerClient struct {
+	httpClient  *http.Client
+	searchCache map[string]*cacheEntry
+	albumCache  map[string]*cacheEntry
+	artistCache map[string]*cacheEntry
+	isrcCache   map[string]string // trackID -> ISRC cache
+	cacheMu     sync.RWMutex
+}
+
+// Singleton instance
+var (
+	deezerClient     *DeezerClient
+	deezerClientOnce sync.Once
+)
+
+// GetDeezerClient returns singleton Deezer client
+func GetDeezerClient() *DeezerClient {
+	deezerClientOnce.Do(func() {
+		deezerClient = &DeezerClient{
+			httpClient:  NewHTTPClientWithTimeout(15 * time.Second),
+			searchCache: make(map[string]*cacheEntry),
+			albumCache:  make(map[string]*cacheEntry),
+			artistCache: make(map[string]*cacheEntry),
+			isrcCache:   make(map[string]string),
+		}
+	})
+	return deezerClient
+}
+
+// Deezer API response types
+type deezerTrack struct {
+	ID            int64             `json:"id"`
+	Title         string            `json:"title"`
+	Duration      int               `json:"duration"` // in seconds
+	TrackPosition int               `json:"track_position"`
+	DiskNumber    int               `json:"disk_number"`
+	ISRC          string            `json:"isrc"`
+	Link          string            `json:"link"`
+	ReleaseDate   string            `json:"release_date"` // Sometimes at track level
+	Artist        deezerArtist      `json:"artist"`
+	Album         deezerAlbumSimple `json:"album"`
+	Contributors  []deezerArtist    `json:"contributors"`
+}
+
+type deezerArtist struct {
+	ID            int64  `json:"id"`
+	Name          string `json:"name"`
+	Picture       string `json:"picture"`
+	PictureMedium string `json:"picture_medium"`
+	PictureBig    string `json:"picture_big"`
+	PictureXL     string `json:"picture_xl"`
+	NbFan         int    `json:"nb_fan"`
+}
+
+type deezerAlbumSimple struct {
+	ID          int64  `json:"id"`
+	Title       string `json:"title"`
+	Cover       string `json:"cover"`
+	CoverMedium string `json:"cover_medium"`
+	CoverBig    string `json:"cover_big"`
+	CoverXL     string `json:"cover_xl"`
+	ReleaseDate string `json:"release_date"` // Sometimes at album level
+}
+
+// ... (skip other structs as they are fine/unchanged) ...
+
+// ... (in convertTrack) ...
+func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
+	artistName := track.Artist.Name
+	if len(track.Contributors) > 0 {
+		names := make([]string, len(track.Contributors))
+		for i, a := range track.Contributors {
+			names[i] = a.Name
+		}
+		artistName = strings.Join(names, ", ")
+	}
+
+	albumImage := track.Album.CoverXL
+	if albumImage == "" {
+		albumImage = track.Album.CoverBig
+	}
+	if albumImage == "" {
+		albumImage = track.Album.CoverMedium
+	}
+	if albumImage == "" {
+		albumImage = track.Album.Cover
+	}
+
+	// Try to find release date
+	releaseDate := track.ReleaseDate
+	if releaseDate == "" {
+		releaseDate = track.Album.ReleaseDate
+	}
+
+	return TrackMetadata{
+		SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
+		Artists:     artistName,
+		Name:        track.Title,
+		AlbumName:   track.Album.Title,
+		AlbumArtist: track.Artist.Name,
+		DurationMS:  track.Duration * 1000,
+		Images:      albumImage,
+		ReleaseDate: releaseDate, // Added this
+		TrackNumber: track.TrackPosition,
+		DiscNumber:  track.DiskNumber,
+		ExternalURL: track.Link,
+		ISRC:        track.ISRC,
+	}
+}
+
+type deezerAlbumFull struct {
+	ID           int64          `json:"id"`
+	Title        string         `json:"title"`
+	Cover        string         `json:"cover"`
+	CoverMedium  string         `json:"cover_medium"`
+	CoverBig     string         `json:"cover_big"`
+	CoverXL      string         `json:"cover_xl"`
+	ReleaseDate  string         `json:"release_date"`
+	NbTracks     int            `json:"nb_tracks"`
+	Artist       deezerArtist   `json:"artist"`
+	Contributors []deezerArtist `json:"contributors"`
+	Tracks       struct {
+		Data []deezerTrack `json:"data"`
+	} `json:"tracks"`
+}
+
+type deezerArtistFull struct {
+	ID            int64  `json:"id"`
+	Name          string `json:"name"`
+	Picture       string `json:"picture"`
+	PictureMedium string `json:"picture_medium"`
+	PictureBig    string `json:"picture_big"`
+	PictureXL     string `json:"picture_xl"`
+	NbFan         int    `json:"nb_fan"`
+	NbAlbum       int    `json:"nb_album"`
+}
+
+type deezerPlaylistFull struct {
+	ID            int64  `json:"id"`
+	Title         string `json:"title"`
+	Picture       string `json:"picture"`
+	PictureMedium string `json:"picture_medium"`
+	PictureBig    string `json:"picture_big"`
+	PictureXL     string `json:"picture_xl"`
+	NbTracks      int    `json:"nb_tracks"`
+	Creator       struct {
+		Name string `json:"name"`
+	} `json:"creator"`
+	Tracks struct {
+		Data []deezerTrack `json:"data"`
+	} `json:"tracks"`
+}
+
+// SearchAll searches for tracks and artists on Deezer
+// NOTE: ISRC is NOT fetched during search for performance - use GetTrackISRC when needed for download
+func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit, artistLimit int) (*SearchAllResult, error) {
+	GoLog("[Deezer] SearchAll: query=%q, trackLimit=%d, artistLimit=%d\n", query, trackLimit, artistLimit)
+
+	cacheKey := fmt.Sprintf("deezer:all:%s:%d:%d", query, trackLimit, artistLimit)
+
+	c.cacheMu.RLock()
+	if entry, ok := c.searchCache[cacheKey]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		GoLog("[Deezer] SearchAll: returning cached result\n")
+		return entry.data.(*SearchAllResult), nil
+	}
+	c.cacheMu.RUnlock()
+
+	result := &SearchAllResult{
+		Tracks:  make([]TrackMetadata, 0),
+		Artists: make([]SearchArtistResult, 0),
+	}
+
+	// Search tracks - NO ISRC fetch for performance
+	trackURL := fmt.Sprintf("%s/track?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), trackLimit)
+	GoLog("[Deezer] Fetching tracks from: %s\n", trackURL)
+
+	var trackResp struct {
+		Data  []deezerTrack `json:"data"`
+		Error *struct {
+			Type    string `json:"type"`
+			Message string `json:"message"`
+			Code    int    `json:"code"`
+		} `json:"error"`
+	}
+	if err := c.getJSON(ctx, trackURL, &trackResp); err != nil {
+		GoLog("[Deezer] Track search failed: %v\n", err)
+		return nil, fmt.Errorf("deezer track search failed: %w", err)
+	}
+
+	if trackResp.Error != nil {
+		GoLog("[Deezer] API error: type=%s, code=%d, message=%s\n", trackResp.Error.Type, trackResp.Error.Code, trackResp.Error.Message)
+		return nil, fmt.Errorf("deezer API error: %s (code %d)", trackResp.Error.Message, trackResp.Error.Code)
+	}
+
+	GoLog("[Deezer] Got %d tracks from API\n", len(trackResp.Data))
+
+	for _, track := range trackResp.Data {
+		// Convert directly without fetching ISRC - much faster
+		result.Tracks = append(result.Tracks, c.convertTrack(track))
+	}
+
+	// Search artists
+	artistURL := fmt.Sprintf("%s/artist?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), artistLimit)
+	GoLog("[Deezer] Fetching artists from: %s\n", artistURL)
+
+	var artistResp struct {
+		Data  []deezerArtist `json:"data"`
+		Error *struct {
+			Type    string `json:"type"`
+			Message string `json:"message"`
+			Code    int    `json:"code"`
+		} `json:"error"`
+	}
+	if err := c.getJSON(ctx, artistURL, &artistResp); err == nil {
+		if artistResp.Error != nil {
+			GoLog("[Deezer] Artist API error: type=%s, code=%d, message=%s\n", artistResp.Error.Type, artistResp.Error.Code, artistResp.Error.Message)
+		} else {
+			GoLog("[Deezer] Got %d artists from API\n", len(artistResp.Data))
+			for _, artist := range artistResp.Data {
+				result.Artists = append(result.Artists, SearchArtistResult{
+					ID:         fmt.Sprintf("deezer:%d", artist.ID),
+					Name:       artist.Name,
+					Images:     c.getBestArtistImage(artist),
+					Followers:  artist.NbFan,
+					Popularity: 0,
+				})
+			}
+		}
+	} else {
+		GoLog("[Deezer] Artist search failed: %v\n", err)
+	}
+
+	GoLog("[Deezer] SearchAll complete: %d tracks, %d artists\n", len(result.Tracks), len(result.Artists))
+
+	// Cache result
+	c.cacheMu.Lock()
+	c.searchCache[cacheKey] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(deezerCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	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)
+
+	var track deezerTrack
+	if err := c.getJSON(ctx, trackURL, &track); err != nil {
+		return nil, err
+	}
+
+	return &TrackResponse{
+		Track: c.convertTrack(track),
+	}, nil
+}
+
+// GetAlbum fetches album with tracks
+// 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() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*AlbumResponsePayload), nil
+	}
+	c.cacheMu.RUnlock()
+
+	albumURL := fmt.Sprintf(deezerAlbumURL, albumID)
+
+	var album deezerAlbumFull
+	if err := c.getJSON(ctx, albumURL, &album); err != nil {
+		return nil, err
+	}
+
+	albumImage := c.getBestAlbumImage(album)
+	artistName := album.Artist.Name
+	if len(album.Contributors) > 0 {
+		names := make([]string, len(album.Contributors))
+		for i, a := range album.Contributors {
+			names[i] = a.Name
+		}
+		artistName = strings.Join(names, ", ")
+	}
+
+	info := AlbumInfoMetadata{
+		TotalTracks: album.NbTracks,
+		Name:        album.Title,
+		ReleaseDate: album.ReleaseDate,
+		Artists:     artistName,
+		Images:      albumImage,
+	}
+
+	// Fetch ISRCs in parallel
+	isrcMap := c.fetchISRCsParallel(ctx, album.Tracks.Data)
+
+	tracks := make([]AlbumTrackMetadata, 0, len(album.Tracks.Data))
+	for _, track := range album.Tracks.Data {
+		trackIDStr := fmt.Sprintf("%d", track.ID)
+		isrc := isrcMap[trackIDStr]
+
+		tracks = append(tracks, AlbumTrackMetadata{
+			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
+			Artists:     track.Artist.Name,
+			Name:        track.Title,
+			AlbumName:   album.Title,
+			AlbumArtist: artistName,
+			DurationMS:  track.Duration * 1000,
+			Images:      albumImage,
+			ReleaseDate: album.ReleaseDate,
+			TrackNumber: track.TrackPosition,
+			TotalTracks: album.NbTracks,
+			DiscNumber:  track.DiskNumber,
+			ExternalURL: track.Link,
+			ISRC:        isrc,
+			AlbumID:     fmt.Sprintf("deezer:%d", album.ID),
+		})
+	}
+
+	result := &AlbumResponsePayload{
+		AlbumInfo: info,
+		TrackList: tracks,
+	}
+
+	c.cacheMu.Lock()
+	c.albumCache[albumID] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(deezerCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	return result, nil
+}
+
+// GetArtist fetches artist with albums
+func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistResponsePayload, error) {
+	c.cacheMu.RLock()
+	if entry, ok := c.artistCache[artistID]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*ArtistResponsePayload), nil
+	}
+	c.cacheMu.RUnlock()
+
+	// Fetch artist info
+	artistURL := fmt.Sprintf(deezerArtistURL, artistID)
+	var artist deezerArtistFull
+	if err := c.getJSON(ctx, artistURL, &artist); err != nil {
+		return nil, err
+	}
+
+	artistInfo := ArtistInfoMetadata{
+		ID:         fmt.Sprintf("deezer:%d", artist.ID),
+		Name:       artist.Name,
+		Images:     c.getBestArtistImageFull(artist),
+		Followers:  artist.NbFan,
+		Popularity: 0,
+	}
+
+	// Fetch artist albums
+	albumsURL := fmt.Sprintf("%s/albums?limit=100", fmt.Sprintf(deezerArtistURL, artistID))
+	var albumsResp struct {
+		Data []struct {
+			ID          int64  `json:"id"`
+			Title       string `json:"title"`
+			ReleaseDate string `json:"release_date"`
+			NbTracks    int    `json:"nb_tracks"`
+			Cover       string `json:"cover"`
+			CoverMedium string `json:"cover_medium"`
+			CoverBig    string `json:"cover_big"`
+			CoverXL     string `json:"cover_xl"`
+			RecordType  string `json:"record_type"` // album, single, ep, compile
+		} `json:"data"`
+	}
+
+	albums := make([]ArtistAlbumMetadata, 0)
+	if err := c.getJSON(ctx, albumsURL, &albumsResp); err == nil {
+		for _, album := range albumsResp.Data {
+			albumType := album.RecordType
+			if albumType == "compile" {
+				albumType = "compilation"
+			}
+
+			coverURL := album.CoverXL
+			if coverURL == "" {
+				coverURL = album.CoverBig
+			}
+			if coverURL == "" {
+				coverURL = album.CoverMedium
+			}
+			if coverURL == "" {
+				coverURL = album.Cover
+			}
+
+			albums = append(albums, ArtistAlbumMetadata{
+				ID:          fmt.Sprintf("deezer:%d", album.ID),
+				Name:        album.Title,
+				ReleaseDate: album.ReleaseDate,
+				TotalTracks: album.NbTracks,
+				Images:      coverURL,
+				AlbumType:   albumType,
+				Artists:     artist.Name,
+			})
+		}
+	}
+
+	result := &ArtistResponsePayload{
+		ArtistInfo: artistInfo,
+		Albums:     albums,
+	}
+
+	c.cacheMu.Lock()
+	c.artistCache[artistID] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(deezerCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	return result, nil
+}
+
+// GetPlaylist fetches playlist with tracks
+// ISRC is fetched in parallel for better performance
+func (c *DeezerClient) GetPlaylist(ctx context.Context, playlistID string) (*PlaylistResponsePayload, error) {
+	playlistURL := fmt.Sprintf(deezerPlaylistURL, playlistID)
+
+	var playlist deezerPlaylistFull
+	if err := c.getJSON(ctx, playlistURL, &playlist); err != nil {
+		return nil, err
+	}
+
+	playlistImage := playlist.PictureXL
+	if playlistImage == "" {
+		playlistImage = playlist.PictureBig
+	}
+	if playlistImage == "" {
+		playlistImage = playlist.PictureMedium
+	}
+
+	var info PlaylistInfoMetadata
+	info.Tracks.Total = playlist.NbTracks
+	info.Owner.DisplayName = playlist.Creator.Name
+	info.Owner.Name = playlist.Title
+	info.Owner.Images = playlistImage
+
+	// Fetch ISRCs in parallel
+	isrcMap := c.fetchISRCsParallel(ctx, playlist.Tracks.Data)
+
+	tracks := make([]AlbumTrackMetadata, 0, len(playlist.Tracks.Data))
+	for _, track := range playlist.Tracks.Data {
+		albumImage := track.Album.CoverXL
+		if albumImage == "" {
+			albumImage = track.Album.CoverBig
+		}
+		if albumImage == "" {
+			albumImage = track.Album.CoverMedium
+		}
+
+		trackIDStr := fmt.Sprintf("%d", track.ID)
+		isrc := isrcMap[trackIDStr]
+
+		tracks = append(tracks, AlbumTrackMetadata{
+			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
+			Artists:     track.Artist.Name,
+			Name:        track.Title,
+			AlbumName:   track.Album.Title,
+			AlbumArtist: track.Artist.Name,
+			DurationMS:  track.Duration * 1000,
+			Images:      albumImage,
+			ReleaseDate: "",
+			TrackNumber: track.TrackPosition,
+			DiscNumber:  track.DiskNumber,
+			ExternalURL: track.Link,
+			ISRC:        isrc,
+			AlbumID:     fmt.Sprintf("deezer:%d", track.Album.ID),
+		})
+	}
+
+	return &PlaylistResponsePayload{
+		PlaylistInfo: info,
+		TrackList:    tracks,
+	}, nil
+}
+
+// SearchByISRC searches for a track by ISRC using direct endpoint
+func (c *DeezerClient) SearchByISRC(ctx context.Context, isrc string) (*TrackMetadata, error) {
+	// Use direct ISRC endpoint (API 2.0)
+	// https://api.deezer.com/2.0/track/isrc:{ISRC}
+	directURL := fmt.Sprintf("%s/track/isrc:%s", deezerBaseURL, isrc)
+
+	var track deezerTrack
+	if err := c.getJSON(ctx, directURL, &track); err != nil {
+		// Fallback to search if direct endpoint fails
+		searchURL := fmt.Sprintf("%s/track?q=isrc:%s&limit=1", deezerSearchURL, isrc)
+		var resp struct {
+			Data []deezerTrack `json:"data"`
+		}
+		if err := c.getJSON(ctx, searchURL, &resp); err != nil {
+			return nil, err
+		}
+		if len(resp.Data) == 0 {
+			return nil, fmt.Errorf("no track found for ISRC: %s", isrc)
+		}
+		result := c.convertTrack(resp.Data[0])
+		return &result, nil
+	}
+
+	// Check if we got a valid response (ID > 0)
+	if track.ID == 0 {
+		return nil, fmt.Errorf("no track found for ISRC: %s", isrc)
+	}
+
+	result := c.convertTrack(track)
+	return &result, nil
+}
+
+func (c *DeezerClient) fetchFullTrack(ctx context.Context, trackID string) (*deezerTrack, error) {
+	trackURL := fmt.Sprintf(deezerTrackURL, trackID)
+	var track deezerTrack
+	if err := c.getJSON(ctx, trackURL, &track); err != nil {
+		return nil, err
+	}
+	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)
+	var resultMu sync.Mutex
+
+	// First, check cache for existing ISRCs
+	var tracksToFetch []deezerTrack
+	c.cacheMu.RLock()
+	for _, track := range tracks {
+		trackIDStr := fmt.Sprintf("%d", track.ID)
+		if isrc, ok := c.isrcCache[trackIDStr]; ok {
+			result[trackIDStr] = isrc
+		} else {
+			tracksToFetch = append(tracksToFetch, track)
+		}
+	}
+	c.cacheMu.RUnlock()
+
+	if len(tracksToFetch) == 0 {
+		return result
+	}
+
+	// Use semaphore to limit concurrent requests
+	sem := make(chan struct{}, deezerMaxParallelISRC)
+	var wg sync.WaitGroup
+
+	for _, track := range tracksToFetch {
+		wg.Add(1)
+		go func(t deezerTrack) {
+			defer wg.Done()
+
+			// Acquire semaphore
+			select {
+			case sem <- struct{}{}:
+				defer func() { <-sem }()
+			case <-ctx.Done():
+				return
+			}
+
+			trackIDStr := fmt.Sprintf("%d", t.ID)
+			fullTrack, err := c.fetchFullTrack(ctx, trackIDStr)
+			if err != nil || fullTrack == nil {
+				return
+			}
+
+			// Store in result and cache
+			resultMu.Lock()
+			result[trackIDStr] = fullTrack.ISRC
+			resultMu.Unlock()
+
+			c.cacheMu.Lock()
+			c.isrcCache[trackIDStr] = fullTrack.ISRC
+			c.cacheMu.Unlock()
+		}(track)
+	}
+
+	wg.Wait()
+	return result
+}
+
+// GetTrackISRC fetches ISRC for a single track (with caching)
+// Use this when you need ISRC for download
+func (c *DeezerClient) GetTrackISRC(ctx context.Context, trackID string) (string, error) {
+	// Check cache first
+	c.cacheMu.RLock()
+	if isrc, ok := c.isrcCache[trackID]; ok {
+		c.cacheMu.RUnlock()
+		return isrc, nil
+	}
+	c.cacheMu.RUnlock()
+
+	// Fetch from API
+	fullTrack, err := c.fetchFullTrack(ctx, trackID)
+	if err != nil {
+		return "", err
+	}
+
+	// Cache the result
+	c.cacheMu.Lock()
+	c.isrcCache[trackID] = fullTrack.ISRC
+	c.cacheMu.Unlock()
+
+	return fullTrack.ISRC, nil
+}
+
+func (c *DeezerClient) getBestArtistImage(artist deezerArtist) string {
+	if artist.PictureXL != "" {
+		return artist.PictureXL
+	}
+	if artist.PictureBig != "" {
+		return artist.PictureBig
+	}
+	if artist.PictureMedium != "" {
+		return artist.PictureMedium
+	}
+	return artist.Picture
+}
+
+func (c *DeezerClient) getBestArtistImageFull(artist deezerArtistFull) string {
+	if artist.PictureXL != "" {
+		return artist.PictureXL
+	}
+	if artist.PictureBig != "" {
+		return artist.PictureBig
+	}
+	if artist.PictureMedium != "" {
+		return artist.PictureMedium
+	}
+	return artist.Picture
+}
+
+func (c *DeezerClient) getBestAlbumImage(album deezerAlbumFull) string {
+	if album.CoverXL != "" {
+		return album.CoverXL
+	}
+	if album.CoverBig != "" {
+		return album.CoverBig
+	}
+	if album.CoverMedium != "" {
+		return album.CoverMedium
+	}
+	return album.Cover
+}
+
+func (c *DeezerClient) getJSON(ctx context.Context, endpoint string, dst interface{}) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("deezer API returned status %d: %s", resp.StatusCode, string(body))
+	}
+
+	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 == "" {
+		return "", "", fmt.Errorf("empty URL")
+	}
+
+	parsed, err := url.Parse(trimmed)
+	if err != nil {
+		return "", "", err
+	}
+
+	if parsed.Host != "www.deezer.com" && parsed.Host != "deezer.com" && parsed.Host != "deezer.page.link" {
+		return "", "", fmt.Errorf("not a Deezer URL")
+	}
+
+	parts := strings.Split(strings.Trim(parsed.Path, "/"), "/")
+
+	// Skip language prefix if present (e.g., /en/, /fr/)
+	if len(parts) > 0 && len(parts[0]) == 2 {
+		parts = parts[1:]
+	}
+
+	if len(parts) < 2 {
+		return "", "", fmt.Errorf("invalid Deezer URL format")
+	}
+
+	resourceType := parts[0]
+	resourceID := parts[1]
+
+	switch resourceType {
+	case "track", "album", "artist", "playlist":
+		return resourceType, resourceID, nil
+	default:
+		return "", "", fmt.Errorf("unsupported Deezer resource type: %s", resourceType)
+	}
+}

go_backend/duplicate.go

@@ -1,49 +1,144 @@
 package gobackend
 
 import (
+	"encoding/json"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
+	"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
+	buildTime time.Time
+	mu        sync.RWMutex
+}
+
+// Global ISRC index cache (per output directory)
+var (
+	isrcIndexCache   = make(map[string]*ISRCIndex)
+	isrcIndexCacheMu sync.RWMutex
+	isrcIndexTTL     = 5 * time.Minute // Cache TTL - rebuild after 5 minutes
+)
+
+// GetISRCIndex returns or builds an ISRC index for the given directory
+func GetISRCIndex(outputDir string) *ISRCIndex {
+	isrcIndexCacheMu.RLock()
+	idx, exists := isrcIndexCache[outputDir]
+	isrcIndexCacheMu.RUnlock()
+
+	// Return cached index if still valid
+	if exists && time.Since(idx.buildTime) < isrcIndexTTL {
+		return idx
+	}
+
+	// Build new index
+	return buildISRCIndex(outputDir)
+}
+
+// buildISRCIndex scans a directory and builds a map of ISRC -> file path
+// Same implementation as PC version for consistency
+func buildISRCIndex(outputDir string) *ISRCIndex {
+	idx := &ISRCIndex{
+		index:     make(map[string]string),
+		outputDir: outputDir,
+		buildTime: time.Now(),
+	}
+
+	if outputDir == "" {
+		return idx
+	}
+
+	startTime := time.Now()
+	fileCount := 0
+
+	// Walk directory - only check .flac files
+	filepath.Walk(outputDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil || info.IsDir() {
+			return nil
+		}
+
+		ext := strings.ToLower(filepath.Ext(path))
+		if ext != ".flac" {
+			return nil
+		}
+
+		// Read ISRC from file
+		metadata, err := ReadMetadata(path)
+		if err != nil || metadata.ISRC == "" {
+			return nil
+		}
+
+		// Store in index (uppercase for case-insensitive matching)
+		idx.index[strings.ToUpper(metadata.ISRC)] = path
+		fileCount++
+		return nil
+	})
+
+	fmt.Printf("[ISRCIndex] Built index for %s: %d files in %v\n", 
+		outputDir, fileCount, time.Since(startTime).Round(time.Millisecond))
+
+	// Cache the index
+	isrcIndexCacheMu.Lock()
+	isrcIndexCache[outputDir] = idx
+	isrcIndexCacheMu.Unlock()
+
+	return idx
+}
+
+// lookup checks if an ISRC exists in the index (internal, returns bool)
+func (idx *ISRCIndex) lookup(isrc string) (string, bool) {
+	if isrc == "" {
+		return "", false
+	}
+
+	idx.mu.RLock()
+	defer idx.mu.RUnlock()
+
+	path, exists := idx.index[strings.ToUpper(isrc)]
+	return path, exists
+}
+
+// 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
+	}
+
+	idx.mu.Lock()
+	defer idx.mu.Unlock()
+
+	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
 	}
 
-	// Walk through directory looking for FLAC files
-	var foundFile string
-	filepath.Walk(outputDir, func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return nil
-		}
-
-		// Only check FLAC files
-		if info.IsDir() || !strings.HasSuffix(strings.ToLower(path), ".flac") {
-			return nil
-		}
-
-		// Read metadata from file
-		metadata, err := ReadMetadata(path)
-		if err != nil {
-			return nil
-		}
-
-		// Check if ISRC matches
-		if metadata.ISRC == isrc {
-			foundFile = path
-			return filepath.SkipAll // Stop walking
-		}
-
-		return nil
-	})
-
-	if foundFile != "" {
-		return foundFile, true
-	}
-
-	return "", false
+	// Use index for fast lookup
+	idx := GetISRCIndex(outputDir)
+	return idx.lookup(isrc)
 }
 
 // CheckISRCExists is the exported version for gomobile (returns string, error)
@@ -61,3 +156,98 @@ 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"`
+	FilePath   string `json:"file_path,omitempty"`
+	TrackName  string `json:"track_name,omitempty"`
+	ArtistName string `json:"artist_name,omitempty"`
+}
+
+// CheckFilesExistParallel checks if multiple files exist in parallel
+// It builds an ISRC index from the output directory once, then checks all tracks against it
+// Same implementation as PC version for consistency
+func CheckFilesExistParallel(outputDir string, tracksJSON string) (string, error) {
+	// Parse input JSON
+	var tracks []struct {
+		ISRC       string `json:"isrc"`
+		TrackName  string `json:"track_name"`
+		ArtistName string `json:"artist_name"`
+	}
+	if err := json.Unmarshal([]byte(tracksJSON), &tracks); err != nil {
+		return "", fmt.Errorf("failed to parse tracks JSON: %w", err)
+	}
+
+	results := make([]FileExistenceResult, len(tracks))
+
+	// Build ISRC index from output directory (scan once)
+	isrcIdx := GetISRCIndex(outputDir)
+
+	// Check each track against the index (parallel)
+	var wg sync.WaitGroup
+	for i, track := range tracks {
+		wg.Add(1)
+		go func(resultIdx int, t struct {
+			ISRC       string `json:"isrc"`
+			TrackName  string `json:"track_name"`
+			ArtistName string `json:"artist_name"`
+		}) {
+			defer wg.Done()
+
+			result := FileExistenceResult{
+				ISRC:       t.ISRC,
+				TrackName:  t.TrackName,
+				ArtistName: t.ArtistName,
+				Exists:     false,
+			}
+
+			if t.ISRC != "" {
+				if filePath, exists := isrcIdx.lookup(t.ISRC); exists {
+					result.Exists = true
+					result.FilePath = filePath
+				}
+			}
+
+			results[resultIdx] = result
+		}(i, track)
+	}
+
+	wg.Wait()
+
+	// Return results as JSON
+	resultJSON, err := json.Marshal(results)
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal results: %w", err)
+	}
+
+	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")
+	}
+
+	buildISRCIndex(outputDir)
+	return nil
+}
+
+// AddToISRCIndex adds a new file to the ISRC index after successful download
+// This avoids rebuilding the entire index
+func AddToISRCIndex(outputDir, isrc, filePath string) {
+	if outputDir == "" || isrc == "" || filePath == "" {
+		return
+	}
+
+	isrcIndexCacheMu.RLock()
+	idx, exists := isrcIndexCache[outputDir]
+	isrcIndexCacheMu.RUnlock()
+
+	if exists {
+		idx.Add(isrc, filePath)
+	}
+}

go_backend/exports.go

@@ -5,6 +5,7 @@ package gobackend
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"strings"
 	"time"
 )
@@ -16,37 +17,43 @@ func ParseSpotifyURL(url string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	
+
 	result := map[string]string{
 		"type": parsed.Type,
 		"id":   parsed.ID,
 	}
-	
+
 	jsonBytes, err := json.Marshal(result)
 	if err != nil {
 		return "", err
 	}
-	
+
 	return string(jsonBytes), nil
 }
 
+// SetSpotifyAPICredentials sets custom Spotify API credentials from Flutter
+// Pass empty strings to use default credentials
+func SetSpotifyAPICredentials(clientID, clientSecret string) {
+	SetSpotifyCredentials(clientID, clientSecret)
+}
+
 // GetSpotifyMetadata fetches metadata from Spotify URL
 // Returns JSON with track/album/playlist data
 func GetSpotifyMetadata(spotifyURL string) (string, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
-	
+
 	client := NewSpotifyMetadataClient()
 	data, err := client.GetFilteredData(ctx, spotifyURL, false, 0)
 	if err != nil {
 		return "", err
 	}
-	
+
 	jsonBytes, err := json.Marshal(data)
 	if err != nil {
 		return "", err
 	}
-	
+
 	return string(jsonBytes), nil
 }
 
@@ -55,18 +62,38 @@ func GetSpotifyMetadata(spotifyURL string) (string, error) {
 func SearchSpotify(query string, limit int) (string, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
 	defer cancel()
-	
+
 	client := NewSpotifyMetadataClient()
 	results, err := client.SearchTracks(ctx, query, limit)
 	if err != nil {
 		return "", err
 	}
-	
+
 	jsonBytes, err := json.Marshal(results)
 	if err != nil {
 		return "", err
 	}
-	
+
+	return string(jsonBytes), nil
+}
+
+// SearchSpotifyAll searches for tracks and artists on Spotify
+// Returns JSON with tracks and artists arrays
+func SearchSpotifyAll(query string, trackLimit, artistLimit int) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	client := NewSpotifyMetadataClient()
+	results, err := client.SearchAll(ctx, query, trackLimit, artistLimit)
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(results)
+	if err != nil {
+		return "", err
+	}
+
 	return string(jsonBytes), nil
 }
 
@@ -78,12 +105,12 @@ func CheckAvailability(spotifyID, isrc string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	
+
 	jsonBytes, err := json.Marshal(availability)
 	if err != nil {
 		return "", err
 	}
-	
+
 	return string(jsonBytes), nil
 }
 
@@ -99,12 +126,15 @@ type DownloadRequest struct {
 	CoverURL             string `json:"cover_url"`
 	OutputDir            string `json:"output_dir"`
 	FilenameFormat       string `json:"filename_format"`
+	Quality              string `json:"quality"` // LOSSLESS, HI_RES, HI_RES_LOSSLESS
 	EmbedLyrics          bool   `json:"embed_lyrics"`
 	EmbedMaxQualityCover bool   `json:"embed_max_quality_cover"`
 	TrackNumber          int    `json:"track_number"`
 	DiscNumber           int    `json:"disc_number"`
 	TotalTracks          int    `json:"total_tracks"`
 	ReleaseDate          string `json:"release_date"`
+	ItemID               string `json:"item_id"`     // Unique ID for progress tracking
+	DurationMS           int    `json:"duration_ms"` // Expected duration in milliseconds (for verification)
 }
 
 // DownloadResponse represents the result of a download
@@ -113,7 +143,34 @@ type DownloadResponse struct {
 	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"
 	AlreadyExists bool   `json:"already_exists,omitempty"`
+	// Actual quality info from the source
+	ActualBitDepth   int    `json:"actual_bit_depth,omitempty"`
+	ActualSampleRate int    `json:"actual_sample_rate,omitempty"`
+	Service          string `json:"service,omitempty"` // Actual service used (for fallback)
+	Title            string `json:"title,omitempty"`
+	Artist           string `json:"artist,omitempty"`
+	Album            string `json:"album,omitempty"`
+	ReleaseDate      string `json:"release_date,omitempty"`
+	TrackNumber      int    `json:"track_number,omitempty"`
+	DiscNumber       int    `json:"disc_number,omitempty"`
+	ISRC             string `json:"isrc,omitempty"`
+}
+
+// DownloadResult is a generic result type for all downloaders
+// DownloadResult is a generic result type for all downloaders
+type DownloadResult struct {
+	FilePath    string
+	BitDepth    int
+	SampleRate  int
+	Title       string
+	Artist      string
+	Album       string
+	ReleaseDate string
+	TrackNumber int
+	DiscNumber  int
+	ISRC        string
 }
 
 // DownloadTrack downloads a track from the specified service
@@ -124,50 +181,132 @@ func DownloadTrack(requestJSON string) (string, error) {
 	if err := json.Unmarshal([]byte(requestJSON), &req); err != nil {
 		return errorResponse("Invalid request: " + err.Error())
 	}
-	
+
 	// Trim whitespace from string fields to prevent filename/path issues
 	req.TrackName = strings.TrimSpace(req.TrackName)
 	req.ArtistName = strings.TrimSpace(req.ArtistName)
 	req.AlbumName = strings.TrimSpace(req.AlbumName)
 	req.AlbumArtist = strings.TrimSpace(req.AlbumArtist)
 	req.OutputDir = strings.TrimSpace(req.OutputDir)
-	
-	var filePath string
+
+	var result DownloadResult
 	var err error
-	
+
 	switch req.Service {
 	case "tidal":
-		filePath, err = downloadFromTidal(req)
+		tidalResult, tidalErr := downloadFromTidal(req)
+		if tidalErr == nil {
+			result = DownloadResult{
+				FilePath:    tidalResult.FilePath,
+				BitDepth:    tidalResult.BitDepth,
+				SampleRate:  tidalResult.SampleRate,
+				Title:       tidalResult.Title,
+				Artist:      tidalResult.Artist,
+				Album:       tidalResult.Album,
+				ReleaseDate: tidalResult.ReleaseDate,
+				TrackNumber: tidalResult.TrackNumber,
+				DiscNumber:  tidalResult.DiscNumber,
+				ISRC:        tidalResult.ISRC,
+			}
+		}
+		err = tidalErr
 	case "qobuz":
-		filePath, err = downloadFromQobuz(req)
+		qobuzResult, qobuzErr := downloadFromQobuz(req)
+		if qobuzErr == nil {
+			result = DownloadResult{
+				FilePath:    qobuzResult.FilePath,
+				BitDepth:    qobuzResult.BitDepth,
+				SampleRate:  qobuzResult.SampleRate,
+				Title:       qobuzResult.Title,
+				Artist:      qobuzResult.Artist,
+				Album:       qobuzResult.Album,
+				ReleaseDate: qobuzResult.ReleaseDate,
+				TrackNumber: qobuzResult.TrackNumber,
+				DiscNumber:  qobuzResult.DiscNumber,
+				ISRC:        qobuzResult.ISRC,
+			}
+		}
+		err = qobuzErr
 	case "amazon":
-		filePath, err = downloadFromAmazon(req)
+		amazonResult, amazonErr := downloadFromAmazon(req)
+		if amazonErr == nil {
+			result = DownloadResult{
+				FilePath:    amazonResult.FilePath,
+				BitDepth:    amazonResult.BitDepth,
+				SampleRate:  amazonResult.SampleRate,
+				Title:       amazonResult.Title,
+				Artist:      amazonResult.Artist,
+				Album:       amazonResult.Album,
+				ReleaseDate: amazonResult.ReleaseDate,
+				TrackNumber: amazonResult.TrackNumber,
+				DiscNumber:  amazonResult.DiscNumber,
+				ISRC:        amazonResult.ISRC,
+			}
+		}
+		err = amazonErr
 	default:
 		return errorResponse("Unknown service: " + req.Service)
 	}
-	
+
 	if err != nil {
 		return errorResponse(err.Error())
 	}
-	
+
 	// Check if file already exists
-	if len(filePath) > 7 && filePath[:7] == "EXISTS:" {
+	if len(result.FilePath) > 7 && result.FilePath[:7] == "EXISTS:" {
+		actualPath := result.FilePath[7:]
+		// Read actual quality from existing file
+		quality, qErr := GetAudioQuality(actualPath)
+		if qErr == nil {
+			result.BitDepth = quality.BitDepth
+			result.SampleRate = quality.SampleRate
+		}
 		resp := DownloadResponse{
-			Success:       true,
-			Message:       "File already exists",
-			FilePath:      filePath[7:],
-			AlreadyExists: true,
+			Success:          true,
+			Message:          "File already exists",
+			FilePath:         actualPath,
+			AlreadyExists:    true,
+			ActualBitDepth:   result.BitDepth,
+			ActualSampleRate: result.SampleRate,
+			Service:          req.Service,
+			Title:            result.Title,
+			Artist:           result.Artist,
+			Album:            result.Album,
+			ReleaseDate:      result.ReleaseDate,
+			TrackNumber:      result.TrackNumber,
+			DiscNumber:       result.DiscNumber,
+			ISRC:             result.ISRC,
 		}
 		jsonBytes, _ := json.Marshal(resp)
 		return string(jsonBytes), nil
 	}
-	
-	resp := DownloadResponse{
-		Success:  true,
-		Message:  "Download complete",
-		FilePath: filePath,
+
+	// Read actual quality from downloaded file (more accurate than API)
+	quality, qErr := GetAudioQuality(result.FilePath)
+	if qErr == nil {
+		result.BitDepth = quality.BitDepth
+		result.SampleRate = quality.SampleRate
+		GoLog("[Download] Actual quality from file: %d-bit/%dHz\n", quality.BitDepth, quality.SampleRate)
+	} else {
+		GoLog("[Download] Could not read quality from file: %v\n", qErr)
 	}
-	
+
+	resp := DownloadResponse{
+		Success:          true,
+		Message:          "Download complete",
+		FilePath:         result.FilePath,
+		ActualBitDepth:   result.BitDepth,
+		ActualSampleRate: result.SampleRate,
+		Service:          req.Service,
+		Title:            result.Title,
+		Artist:           result.Artist,
+		Album:            result.Album,
+		ReleaseDate:      result.ReleaseDate,
+		TrackNumber:      result.TrackNumber,
+		DiscNumber:       result.DiscNumber,
+		ISRC:             result.ISRC,
+	}
+
 	jsonBytes, _ := json.Marshal(resp)
 	return string(jsonBytes), nil
 }
@@ -179,21 +318,23 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 	if err := json.Unmarshal([]byte(requestJSON), &req); err != nil {
 		return errorResponse("Invalid request: " + err.Error())
 	}
-	
+
 	// Trim whitespace from string fields to prevent filename/path issues
 	req.TrackName = strings.TrimSpace(req.TrackName)
 	req.ArtistName = strings.TrimSpace(req.ArtistName)
 	req.AlbumName = strings.TrimSpace(req.AlbumName)
 	req.AlbumArtist = strings.TrimSpace(req.AlbumArtist)
 	req.OutputDir = strings.TrimSpace(req.OutputDir)
-	
+
 	// Build service order starting with preferred service
 	allServices := []string{"tidal", "qobuz", "amazon"}
 	preferredService := req.Service
 	if preferredService == "" {
 		preferredService = "tidal"
 	}
-	
+
+	GoLog("[DownloadWithFallback] Preferred service from request: '%s'\n", req.Service)
+
 	// Create ordered list: preferred first, then others
 	services := []string{preferredService}
 	for _, s := range allServices {
@@ -201,49 +342,140 @@ func DownloadWithFallback(requestJSON string) (string, error) {
 			services = append(services, s)
 		}
 	}
-	
+
+	GoLog("[DownloadWithFallback] Service order: %v\n", services)
+
 	var lastErr error
-	
+
 	for _, service := range services {
+		GoLog("[DownloadWithFallback] Trying service: %s\n", service)
 		req.Service = service
-		
-		var filePath string
+
+		var result DownloadResult
 		var err error
-		
+
 		switch service {
 		case "tidal":
-			filePath, err = downloadFromTidal(req)
+			tidalResult, tidalErr := downloadFromTidal(req)
+			if tidalErr == nil {
+				result = DownloadResult{
+					FilePath:    tidalResult.FilePath,
+					BitDepth:    tidalResult.BitDepth,
+					SampleRate:  tidalResult.SampleRate,
+					Title:       tidalResult.Title,
+					Artist:      tidalResult.Artist,
+					Album:       tidalResult.Album,
+					ReleaseDate: tidalResult.ReleaseDate,
+					TrackNumber: tidalResult.TrackNumber,
+					DiscNumber:  tidalResult.DiscNumber,
+					ISRC:        tidalResult.ISRC,
+				}
+			} else {
+				GoLog("[DownloadWithFallback] Tidal error: %v\n", tidalErr)
+			}
+			err = tidalErr
 		case "qobuz":
-			filePath, err = downloadFromQobuz(req)
+			qobuzResult, qobuzErr := downloadFromQobuz(req)
+			if qobuzErr == nil {
+				result = DownloadResult{
+					FilePath:    qobuzResult.FilePath,
+					BitDepth:    qobuzResult.BitDepth,
+					SampleRate:  qobuzResult.SampleRate,
+					Title:       qobuzResult.Title,
+					Artist:      qobuzResult.Artist,
+					Album:       qobuzResult.Album,
+					ReleaseDate: qobuzResult.ReleaseDate,
+					TrackNumber: qobuzResult.TrackNumber,
+					DiscNumber:  qobuzResult.DiscNumber,
+					ISRC:        qobuzResult.ISRC,
+				}
+			} else {
+				GoLog("[DownloadWithFallback] Qobuz error: %v\n", qobuzErr)
+			}
+			err = qobuzErr
 		case "amazon":
-			filePath, err = downloadFromAmazon(req)
+			amazonResult, amazonErr := downloadFromAmazon(req)
+			if amazonErr == nil {
+				result = DownloadResult{
+					FilePath:    amazonResult.FilePath,
+					BitDepth:    amazonResult.BitDepth,
+					SampleRate:  amazonResult.SampleRate,
+					Title:       amazonResult.Title,
+					Artist:      amazonResult.Artist,
+					Album:       amazonResult.Album,
+					ReleaseDate: amazonResult.ReleaseDate,
+					TrackNumber: amazonResult.TrackNumber,
+					DiscNumber:  amazonResult.DiscNumber,
+					ISRC:        amazonResult.ISRC,
+				}
+			} else {
+				GoLog("[DownloadWithFallback] Amazon error: %v\n", amazonErr)
+			}
+			err = amazonErr
 		}
-		
+
 		if err == nil {
 			// Check if file already exists
-			if len(filePath) > 7 && filePath[:7] == "EXISTS:" {
+			if len(result.FilePath) > 7 && result.FilePath[:7] == "EXISTS:" {
+				actualPath := result.FilePath[7:]
+				// Read actual quality from existing file
+				quality, qErr := GetAudioQuality(actualPath)
+				if qErr == nil {
+					result.BitDepth = quality.BitDepth
+					result.SampleRate = quality.SampleRate
+				}
 				resp := DownloadResponse{
-					Success:       true,
-					Message:       "File already exists",
-					FilePath:      filePath[7:],
-					AlreadyExists: true,
+					Success:          true,
+					Message:          "File already exists",
+					FilePath:         actualPath,
+					AlreadyExists:    true,
+					ActualBitDepth:   result.BitDepth,
+					ActualSampleRate: result.SampleRate,
+					Service:          service,
+					Title:            result.Title,
+					Artist:           result.Artist,
+					Album:            result.Album,
+					ReleaseDate:      result.ReleaseDate,
+					TrackNumber:      result.TrackNumber,
+					DiscNumber:       result.DiscNumber,
+					ISRC:             result.ISRC,
 				}
 				jsonBytes, _ := json.Marshal(resp)
 				return string(jsonBytes), nil
 			}
-			
+
+			// Read actual quality from downloaded file (more accurate than API)
+			quality, qErr := GetAudioQuality(result.FilePath)
+			if qErr == nil {
+				result.BitDepth = quality.BitDepth
+				result.SampleRate = quality.SampleRate
+				GoLog("[Download] Actual quality from file: %d-bit/%dHz\n", quality.BitDepth, quality.SampleRate)
+			} else {
+				GoLog("[Download] Could not read quality from file: %v\n", qErr)
+			}
+
 			resp := DownloadResponse{
-				Success:  true,
-				Message:  "Downloaded from " + service,
-				FilePath: filePath,
+				Success:          true,
+				Message:          "Downloaded from " + service,
+				FilePath:         result.FilePath,
+				ActualBitDepth:   result.BitDepth,
+				ActualSampleRate: result.SampleRate,
+				Service:          service,
+				Title:            result.Title,
+				Artist:           result.Artist,
+				Album:            result.Album,
+				ReleaseDate:      result.ReleaseDate,
+				TrackNumber:      result.TrackNumber,
+				DiscNumber:       result.DiscNumber,
+				ISRC:             result.ISRC,
 			}
 			jsonBytes, _ := json.Marshal(resp)
 			return string(jsonBytes), nil
 		}
-		
+
 		lastErr = err
 	}
-	
+
 	return errorResponse("All services failed. Last error: " + lastErr.Error())
 }
 
@@ -254,12 +486,78 @@ func GetDownloadProgress() string {
 	return string(jsonBytes)
 }
 
+// GetAllDownloadProgress returns progress for all active downloads (concurrent mode)
+func GetAllDownloadProgress() string {
+	return GetMultiProgress()
+}
+
+// InitItemProgress initializes progress tracking for a download item
+func InitItemProgress(itemID string) {
+	StartItemProgress(itemID)
+}
+
+// FinishItemProgress marks a download item as complete and removes tracking
+func FinishItemProgress(itemID string) {
+	CompleteItemProgress(itemID)
+	// Don't remove immediately - let Flutter poll one more time to see 100%
+}
+
+// ClearItemProgress removes progress tracking for a specific item
+func ClearItemProgress(itemID string) {
+	RemoveItemProgress(itemID)
+}
+
 // CleanupConnections closes idle HTTP connections
 // Call this periodically during large batch downloads to prevent TCP exhaustion
 func CleanupConnections() {
 	CloseIdleConnections()
 }
 
+// ReadFileMetadata reads metadata directly from a FLAC file
+// Returns JSON with all embedded metadata (title, artist, album, track number, etc.)
+// This is useful for displaying accurate metadata in the UI without relying on cached data
+func ReadFileMetadata(filePath string) (string, error) {
+	metadata, err := ReadMetadata(filePath)
+	if err != nil {
+		return "", fmt.Errorf("failed to read metadata: %w", err)
+	}
+
+	// Also get audio quality info
+	quality, qualityErr := GetAudioQuality(filePath)
+
+	// Get duration from FLAC stream info
+	duration := 0
+	if qualityErr == nil && quality.SampleRate > 0 && quality.TotalSamples > 0 {
+		duration = int(quality.TotalSamples / int64(quality.SampleRate))
+	}
+
+	result := map[string]interface{}{
+		"title":        metadata.Title,
+		"artist":       metadata.Artist,
+		"album":        metadata.Album,
+		"album_artist": metadata.AlbumArtist,
+		"date":         metadata.Date,
+		"track_number": metadata.TrackNumber,
+		"disc_number":  metadata.DiscNumber,
+		"isrc":         metadata.ISRC,
+		"lyrics":       metadata.Lyrics,
+		"duration":     duration,
+	}
+
+	// Add quality info if available
+	if qualityErr == nil {
+		result["bit_depth"] = quality.BitDepth
+		result["sample_rate"] = quality.SampleRate
+	}
+
+	jsonBytes, err := json.Marshal(result)
+	if err != nil {
+		return "", err
+	}
+
+	return string(jsonBytes), nil
+}
+
 // SetDownloadDirectory sets the default download directory
 func SetDownloadDirectory(path string) error {
 	return setDownloadDir(path)
@@ -268,27 +566,47 @@ func SetDownloadDirectory(path string) error {
 // CheckDuplicate checks if a file with the given ISRC exists
 func CheckDuplicate(outputDir, isrc string) (string, error) {
 	existingFile, exists := CheckISRCExists(outputDir, isrc)
-	
+
 	result := map[string]interface{}{
 		"exists":   exists,
 		"filepath": existingFile,
 	}
-	
+
 	jsonBytes, err := json.Marshal(result)
 	if err != nil {
 		return "", err
 	}
-	
+
 	return string(jsonBytes), nil
 }
 
+// CheckDuplicatesBatch checks multiple files for duplicates in parallel
+// Uses ISRC index for fast lookup (builds index once, checks all tracks)
+// tracksJSON format: [{"isrc": "...", "track_name": "...", "artist_name": "..."}, ...]
+// Returns JSON array of results
+func CheckDuplicatesBatch(outputDir, tracksJSON string) (string, error) {
+	return CheckFilesExistParallel(outputDir, tracksJSON)
+}
+
+// PreBuildDuplicateIndex pre-builds the ISRC index for a directory
+// Call this when entering album/playlist screen for faster duplicate checking
+func PreBuildDuplicateIndex(outputDir string) error {
+	return PreBuildISRCIndex(outputDir)
+}
+
+// InvalidateDuplicateIndex clears the ISRC index cache for a directory
+// Call this when files are deleted or moved
+func InvalidateDuplicateIndex(outputDir string) {
+	InvalidateISRCCache(outputDir)
+}
+
 // BuildFilename builds a filename from template and metadata
 func BuildFilename(template string, metadataJSON string) (string, error) {
 	var metadata map[string]interface{}
 	if err := json.Unmarshal([]byte(metadataJSON), &metadata); err != nil {
 		return "", err
 	}
-	
+
 	filename := buildFilenameFromTemplate(template, metadata)
 	return filename, nil
 }
@@ -322,15 +640,26 @@ func FetchLyrics(spotifyID, trackName, artistName string) (string, error) {
 	return string(jsonBytes), nil
 }
 
-// GetLyricsLRC fetches lyrics and converts to LRC format string
-func GetLyricsLRC(spotifyID, trackName, artistName string) (string, error) {
+// GetLyricsLRC fetches lyrics and converts to LRC format string with metadata headers
+// First tries to extract from file, then falls back to fetching from internet
+func GetLyricsLRC(spotifyID, trackName, artistName string, filePath string) (string, error) {
+	// Try to extract from file first (much faster)
+	if filePath != "" {
+		lyrics, err := ExtractLyrics(filePath)
+		if err == nil && lyrics != "" {
+			return lyrics, nil
+		}
+	}
+
+	// Fallback to fetching from internet
 	client := NewLyricsClient()
-	lyrics, err := client.FetchLyricsAllSources(spotifyID, trackName, artistName)
+	lyricsData, err := client.FetchLyricsAllSources(spotifyID, trackName, artistName)
 	if err != nil {
 		return "", err
 	}
 
-	lrcContent := convertToLRC(lyrics)
+	// Convert to LRC format with metadata headers (like PC version)
+	lrcContent := convertToLRCWithMetadata(lyricsData, trackName, artistName)
 	return lrcContent, nil
 }
 
@@ -350,10 +679,339 @@ func EmbedLyricsToFile(filePath, lyrics string) (string, error) {
 	return string(jsonBytes), nil
 }
 
+// PreWarmTrackCacheJSON pre-warms the track ID cache for album/playlist tracks
+// tracksJSON is a JSON array of objects with: isrc, track_name, artist_name, spotify_id, service
+// This runs in background and returns immediately
+func PreWarmTrackCacheJSON(tracksJSON string) (string, error) {
+	var tracks []struct {
+		ISRC       string `json:"isrc"`
+		TrackName  string `json:"track_name"`
+		ArtistName string `json:"artist_name"`
+		SpotifyID  string `json:"spotify_id"`
+		Service    string `json:"service"`
+	}
+
+	if err := json.Unmarshal([]byte(tracksJSON), &tracks); err != nil {
+		return errorResponse("Invalid JSON: " + err.Error())
+	}
+
+	// Convert to PreWarmCacheRequest
+	requests := make([]PreWarmCacheRequest, len(tracks))
+	for i, t := range tracks {
+		requests[i] = PreWarmCacheRequest{
+			ISRC:       t.ISRC,
+			TrackName:  t.TrackName,
+			ArtistName: t.ArtistName,
+			SpotifyID:  t.SpotifyID,
+			Service:    t.Service,
+		}
+	}
+
+	// Run in background
+	go PreWarmTrackCache(requests)
+
+	resp := map[string]interface{}{
+		"success": true,
+		"message": fmt.Sprintf("Pre-warming cache for %d tracks in background", len(tracks)),
+	}
+
+	jsonBytes, _ := json.Marshal(resp)
+	return string(jsonBytes), nil
+}
+
+// GetTrackCacheSize returns the current track ID cache size
+func GetTrackCacheSize() int {
+	return GetCacheSize()
+}
+
+// ClearTrackIDCache clears the track ID cache
+func ClearTrackIDCache() {
+	ClearTrackCache()
+}
+
+// ==================== DEEZER API ====================
+
+// SearchDeezerAll searches for tracks and artists on Deezer (no API key required)
+// Returns JSON with tracks and artists arrays
+func SearchDeezerAll(query string, trackLimit, artistLimit int) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	client := GetDeezerClient()
+	results, err := client.SearchAll(ctx, query, trackLimit, artistLimit)
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(results)
+	if err != nil {
+		return "", err
+	}
+
+	return string(jsonBytes), nil
+}
+
+// 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()
+
+	client := GetDeezerClient()
+	var data interface{}
+	var err error
+
+	switch resourceType {
+	case "track":
+		data, err = client.GetTrack(ctx, resourceID)
+	case "album":
+		data, err = client.GetAlbum(ctx, resourceID)
+	case "artist":
+		data, err = client.GetArtist(ctx, resourceID)
+	case "playlist":
+		data, err = client.GetPlaylist(ctx, resourceID)
+	default:
+		return "", fmt.Errorf("unsupported Deezer resource type: %s", resourceType)
+	}
+
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(data)
+	if err != nil {
+		return "", err
+	}
+
+	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 {
+		return "", err
+	}
+
+	result := map[string]string{
+		"type": resourceType,
+		"id":   resourceID,
+	}
+
+	jsonBytes, err := json.Marshal(result)
+	if err != nil {
+		return "", err
+	}
+
+	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()
+
+	client := GetDeezerClient()
+	track, err := client.SearchByISRC(ctx, isrc)
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(track)
+	if err != nil {
+		return "", err
+	}
+
+	return string(jsonBytes), nil
+}
+
+// ConvertSpotifyToDeezer converts a Spotify track/album ID to Deezer and fetches metadata
+// This uses SongLink API to find the Deezer equivalent, then fetches from Deezer
+// Useful when Spotify API is rate limited
+func ConvertSpotifyToDeezer(resourceType, spotifyID string) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	songlink := NewSongLinkClient()
+	deezerClient := GetDeezerClient()
+
+	// For tracks, we can use SongLink to get Deezer ID
+	if resourceType == "track" {
+		deezerID, err := songlink.GetDeezerIDFromSpotify(spotifyID)
+		if err != nil {
+			return "", fmt.Errorf("could not find Deezer equivalent: %w", err)
+		}
+
+		// Fetch metadata from Deezer
+		trackResp, err := deezerClient.GetTrack(ctx, deezerID)
+		if err != nil {
+			return "", fmt.Errorf("failed to fetch Deezer metadata: %w", err)
+		}
+
+		jsonBytes, err := json.Marshal(trackResp)
+		if err != nil {
+			return "", err
+		}
+
+		return string(jsonBytes), nil
+	}
+
+	// For albums, SongLink also provides mapping
+	if resourceType == "album" {
+		deezerID, err := songlink.GetDeezerAlbumIDFromSpotify(spotifyID)
+		if err != nil {
+			return "", fmt.Errorf("could not find Deezer album: %w", err)
+		}
+
+		// Fetch album metadata from Deezer
+		albumResp, err := deezerClient.GetAlbum(ctx, deezerID)
+		if err != nil {
+			return "", fmt.Errorf("failed to fetch Deezer album metadata: %w", err)
+		}
+
+		jsonBytes, err := json.Marshal(albumResp)
+		if err != nil {
+			return "", err
+		}
+
+		return string(jsonBytes), nil
+	}
+
+	// For artists/playlists, SongLink doesn't provide direct mapping
+	return "", fmt.Errorf("Spotify to Deezer conversion only supported for tracks and albums. Please search by name for %s", resourceType)
+}
+
+// GetSpotifyMetadataWithDeezerFallback tries Spotify first, falls back to Deezer on rate limit
+func GetSpotifyMetadataWithDeezerFallback(spotifyURL string) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	// Try Spotify first
+	client := NewSpotifyMetadataClient()
+	data, err := client.GetFilteredData(ctx, spotifyURL, false, 0)
+	if err == nil {
+		jsonBytes, err := json.Marshal(data)
+		if err != nil {
+			return "", err
+		}
+		return string(jsonBytes), nil
+	}
+
+	// Check if it's a rate limit error
+	errStr := strings.ToLower(err.Error())
+	if !strings.Contains(errStr, "429") && !strings.Contains(errStr, "rate") && !strings.Contains(errStr, "limit") {
+		// Not a rate limit error, return original error
+		return "", err
+	}
+
+	// Rate limited - try Deezer fallback for tracks and albums
+	parsed, parseErr := parseSpotifyURI(spotifyURL)
+	if parseErr != nil {
+		return "", fmt.Errorf("spotify rate limited and failed to parse URL: %w", parseErr)
+	}
+
+	GoLog("[Fallback] Spotify rate limited for %s, trying Deezer...\n", parsed.Type)
+
+	if parsed.Type == "track" || parsed.Type == "album" {
+		// Convert to Deezer
+		return ConvertSpotifyToDeezer(parsed.Type, parsed.ID)
+	}
+
+	// Artist and playlist not supported for fallback
+	if parsed.Type == "artist" {
+		return "", fmt.Errorf("spotify rate limited. Artist pages require Spotify API - please try again later")
+	}
+
+	return "", fmt.Errorf("spotify rate limited. Playlists are user-specific and require Spotify API")
+}
+
+// ==================== SONGLINK DEEZER SUPPORT ====================
+
+// CheckAvailabilityFromDeezerID checks track availability using Deezer track ID as source
+// Returns JSON with availability info for Spotify, Tidal, Amazon, etc.
+func CheckAvailabilityFromDeezerID(deezerTrackID string) (string, error) {
+	client := NewSongLinkClient()
+	availability, err := client.CheckAvailabilityFromDeezer(deezerTrackID)
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(availability)
+	if err != nil {
+		return "", err
+	}
+
+	return string(jsonBytes), nil
+}
+
+// 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)
+	if err != nil {
+		return "", err
+	}
+
+	jsonBytes, err := json.Marshal(availability)
+	if err != nil {
+		return "", err
+	}
+
+	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)
+}
+
 func errorResponse(msg string) (string, error) {
+	// Determine error type based on message
+	errorType := "unknown"
+	lowerMsg := strings.ToLower(msg)
+
+	if strings.Contains(lowerMsg, "isp blocking") ||
+		strings.Contains(lowerMsg, "try using vpn") ||
+		strings.Contains(lowerMsg, "change dns") {
+		errorType = "isp_blocked"
+	} else if strings.Contains(lowerMsg, "not found") ||
+		strings.Contains(lowerMsg, "not available") ||
+		strings.Contains(lowerMsg, "no results") ||
+		strings.Contains(lowerMsg, "track not found") ||
+		strings.Contains(lowerMsg, "all services failed") {
+		errorType = "not_found"
+	} else if strings.Contains(lowerMsg, "rate limit") ||
+		strings.Contains(lowerMsg, "429") ||
+		strings.Contains(lowerMsg, "too many requests") {
+		errorType = "rate_limit"
+	} else if strings.Contains(lowerMsg, "network") ||
+		strings.Contains(lowerMsg, "connection") ||
+		strings.Contains(lowerMsg, "timeout") ||
+		strings.Contains(lowerMsg, "dial") {
+		errorType = "network"
+	}
+
 	resp := DownloadResponse{
-		Success: false,
-		Error:   msg,
+		Success:   false,
+		Error:     msg,
+		ErrorType: errorType,
 	}
 	jsonBytes, _ := json.Marshal(resp)
 	return string(jsonBytes), nil

go_backend/httputil.go

@@ -1,36 +1,75 @@
 package gobackend
 
 import (
+	"crypto/tls"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
 	"net"
 	"net/http"
+	"net/url"
 	"strconv"
+	"strings"
+	"syscall"
 	"time"
 )
 
 // HTTP utility functions for consistent request handling across all downloaders
 
-// User-Agent pool for Android Chrome browsers
-var userAgentTemplates = []string{
-	"Mozilla/5.0 (Linux; Android %d; SM-G%d) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Mobile Safari/537.36",
-	"Mozilla/5.0 (Linux; Android %d; Pixel %d) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Mobile Safari/537.36",
-	"Mozilla/5.0 (Linux; Android %d; SM-A%d) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Mobile Safari/537.36",
-	"Mozilla/5.0 (Linux; Android %d; Redmi Note %d) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Mobile Safari/537.36",
+// getRandomUserAgent generates a random Windows Chrome User-Agent string
+// Uses same format as PC version (referensi/backend/spotify_metadata.go) for better API compatibility
+func getRandomUserAgent() string {
+	// Windows 10/11 Chrome format - same as PC version for maximum compatibility
+	// Some APIs may block mobile User-Agents, so we use desktop format
+	winMajor := rand.Intn(2) + 10  // Windows 10 or 11
+	
+	chromeVersion := rand.Intn(25) + 100 // Chrome 100-124
+	chromeBuild := rand.Intn(1500) + 3000 // Build 3000-4500
+	chromePatch := rand.Intn(65) + 60 // Patch 60-125
+	
+	return fmt.Sprintf(
+		"Mozilla/5.0 (Windows NT %d.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Safari/537.36",
+		winMajor,
+		chromeVersion,
+		chromeBuild,
+		chromePatch,
+	)
 }
 
-// getRandomUserAgent generates a random browser-like User-Agent string (Android Chrome format)
-func getRandomUserAgent() string {
-	template := userAgentTemplates[rand.Intn(len(userAgentTemplates))]
+// getRandomMacUserAgent generates a random Mac Chrome User-Agent string
+// Alternative format matching referensi/backend/spotify_metadata.go exactly
+func getRandomMacUserAgent() string {
+	macMajor := rand.Intn(4) + 11  // macOS 11-14
+	macMinor := rand.Intn(5) + 4   // Minor 4-8
+	webkitMajor := rand.Intn(7) + 530
+	webkitMinor := rand.Intn(7) + 30
+	chromeMajor := rand.Intn(25) + 80
+	chromeBuild := rand.Intn(1500) + 3000
+	chromePatch := rand.Intn(65) + 60
+	safariMajor := rand.Intn(7) + 530
+	safariMinor := rand.Intn(6) + 30
 
-	androidVersion := rand.Intn(5) + 10 // Android 10-14
-	deviceModel := rand.Intn(900) + 100 // Random model number
-	chromeVersion := rand.Intn(25) + 100 // Chrome 100-124
-	chromeBuild := rand.Intn(5000) + 5000
-	chromePatch := rand.Intn(200) + 100
+	return fmt.Sprintf(
+		"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_%d_%d) AppleWebKit/%d.%d (KHTML, like Gecko) Chrome/%d.0.%d.%d Safari/%d.%d",
+		macMajor,
+		macMinor,
+		webkitMajor,
+		webkitMinor,
+		chromeMajor,
+		chromeBuild,
+		chromePatch,
+		safariMajor,
+		safariMinor,
+	)
+}
 
-	return fmt.Sprintf(template, androidVersion, deviceModel, chromeVersion, chromeBuild, chromePatch)
+// getRandomDesktopUserAgent randomly picks between Windows and Mac User-Agent
+func getRandomDesktopUserAgent() string {
+	if rand.Intn(2) == 0 {
+		return getRandomUserAgent() // Windows
+	}
+	return getRandomMacUserAgent() // Mac
 }
 
 // Default timeout values
@@ -43,6 +82,7 @@ const (
 )
 
 // Shared transport with connection pooling to prevent TCP exhaustion
+// Optimized for large file downloads (FLAC ~30-50MB)
 var sharedTransport = &http.Transport{
 	DialContext: (&net.Dialer{
 		Timeout:   30 * time.Second,
@@ -56,6 +96,9 @@ var sharedTransport = &http.Transport{
 	ExpectContinueTimeout: 1 * time.Second,
 	DisableKeepAlives:     false, // Enable keep-alives for connection reuse
 	ForceAttemptHTTP2:     true,
+	WriteBufferSize:       64 * 1024,  // 64KB write buffer
+	ReadBufferSize:        64 * 1024,  // 64KB read buffer
+	DisableCompression:    true,       // FLAC is already compressed
 }
 
 // Shared HTTP client for general requests (reuses connections)
@@ -96,9 +139,15 @@ func CloseIdleConnections() {
 }
 
 // DoRequestWithUserAgent executes an HTTP request with a random User-Agent header
+// Also checks for ISP blocking on errors
 func DoRequestWithUserAgent(client *http.Client, req *http.Request) (*http.Response, error) {
 	req.Header.Set("User-Agent", getRandomUserAgent())
-	return client.Do(req)
+	resp, err := client.Do(req)
+	if err != nil {
+		// Check for ISP blocking
+		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
+	}
+	return resp, err
 }
 
 // RetryConfig holds configuration for retry logic
@@ -121,9 +170,11 @@ 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
+	requestURL := req.URL.String()
 
 	for attempt := 0; attempt <= config.MaxRetries; attempt++ {
 		// Clone request for retry (body needs to be re-readable)
@@ -133,7 +184,16 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 		resp, err := client.Do(reqCopy)
 		if err != nil {
 			lastErr = err
+			
+			// Check for ISP blocking on network errors
+			if CheckAndLogISPBlocking(err, requestURL, "HTTP") {
+				// Don't retry if ISP blocking is detected - it won't help
+				return nil, WrapErrorWithISPCheck(err, requestURL, "HTTP")
+			}
+			
 			if attempt < config.MaxRetries {
+				GoLog("[HTTP] Request failed (attempt %d/%d): %v, retrying in %v...\n", 
+					attempt+1, config.MaxRetries+1, err, delay)
 				time.Sleep(delay)
 				delay = calculateNextDelay(delay, config)
 			}
@@ -154,17 +214,43 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			}
 			lastErr = fmt.Errorf("rate limited (429)")
 			if attempt < config.MaxRetries {
+				GoLog("[HTTP] Rate limited, waiting %v before retry...\n", delay)
 				time.Sleep(delay)
 				delay = calculateNextDelay(delay, config)
 			}
 			continue
 		}
 
+		// Check for ISP blocking via HTTP status codes
+		// Some ISPs return 403 or 451 when blocking content
+		if resp.StatusCode == 403 || resp.StatusCode == 451 {
+			body, _ := io.ReadAll(resp.Body)
+			resp.Body.Close()
+			bodyStr := strings.ToLower(string(body))
+			
+			// Check if response looks like ISP blocking page
+			ispBlockingIndicators := []string{
+				"blocked", "forbidden", "access denied", "not available in your",
+				"restricted", "censored", "unavailable for legal", "blocked by",
+			}
+			
+			for _, indicator := range ispBlockingIndicators {
+				if strings.Contains(bodyStr, indicator) {
+					LogError("HTTP", "ISP BLOCKING DETECTED via HTTP %d response", resp.StatusCode)
+					LogError("HTTP", "Domain: %s", req.URL.Host)
+					LogError("HTTP", "Response contains: %s", indicator)
+					LogError("HTTP", "Suggestion: Try using a VPN or changing your DNS to 1.1.1.1 or 8.8.8.8")
+					return nil, fmt.Errorf("ISP blocking detected for %s (HTTP %d) - try using VPN or change DNS", req.URL.Host, resp.StatusCode)
+				}
+			}
+		}
+
 		// Server errors (5xx) - retry
 		if resp.StatusCode >= 500 {
 			resp.Body.Close()
 			lastErr = fmt.Errorf("server error: HTTP %d", resp.StatusCode)
 			if attempt < config.MaxRetries {
+				GoLog("[HTTP] Server error %d, retrying in %v...\n", resp.StatusCode, delay)
 				time.Sleep(delay)
 				delay = calculateNextDelay(delay, config)
 			}
@@ -258,3 +344,172 @@ func BuildErrorMessage(apiURL string, statusCode int, responsePreview string) st
 	}
 	return msg
 }
+
+// ISPBlockingError represents an error caused by ISP blocking
+type ISPBlockingError struct {
+	Domain      string
+	Reason      string
+	OriginalErr error
+}
+
+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 {
+			return &ISPBlockingError{
+				Domain:      domain,
+				Reason:      "DNS resolution failed - domain may be blocked by ISP",
+				OriginalErr: err,
+			}
+		}
+	}
+
+	// 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 {
+				case syscall.ECONNREFUSED:
+					return &ISPBlockingError{
+						Domain:      domain,
+						Reason:      "Connection refused - port may be blocked by ISP/firewall",
+						OriginalErr: err,
+					}
+				case syscall.ECONNRESET:
+					return &ISPBlockingError{
+						Domain:      domain,
+						Reason:      "Connection reset - ISP may be intercepting traffic",
+						OriginalErr: err,
+					}
+				case syscall.ETIMEDOUT:
+					return &ISPBlockingError{
+						Domain:      domain,
+						Reason:      "Connection timed out - ISP may be blocking access",
+						OriginalErr: err,
+					}
+				case syscall.ENETUNREACH:
+					return &ISPBlockingError{
+						Domain:      domain,
+						Reason:      "Network unreachable - ISP may be blocking route",
+						OriginalErr: err,
+					}
+				case syscall.EHOSTUNREACH:
+					return &ISPBlockingError{
+						Domain:      domain,
+						Reason:      "Host unreachable - ISP may be blocking destination",
+						OriginalErr: err,
+					}
+				}
+			}
+		}
+	}
+
+	// Check for TLS handshake failure (ISP MITM or blocking HTTPS)
+	var tlsErr *tls.RecordHeaderError
+	if errors.As(err, &tlsErr) {
+		return &ISPBlockingError{
+			Domain:      domain,
+			Reason:      "TLS handshake failed - ISP may be intercepting HTTPS traffic",
+			OriginalErr: err,
+		}
+	}
+
+	// Check error message patterns for common ISP blocking indicators
+	blockingPatterns := []struct {
+		pattern string
+		reason  string
+	}{
+		{"connection reset by peer", "Connection reset - ISP may be intercepting traffic"},
+		{"connection refused", "Connection refused - port may be blocked"},
+		{"no such host", "DNS lookup failed - domain may be blocked by ISP"},
+		{"i/o timeout", "Connection timed out - ISP may be blocking access"},
+		{"network is unreachable", "Network unreachable - ISP may be blocking route"},
+		{"tls: ", "TLS error - ISP may be intercepting HTTPS traffic"},
+		{"certificate", "Certificate error - ISP may be using MITM proxy"},
+		{"eof", "Connection closed unexpectedly - ISP may be blocking"},
+		{"context deadline exceeded", "Request timed out - ISP may be throttling"},
+	}
+
+	for _, bp := range blockingPatterns {
+		if strings.Contains(errStr, bp.pattern) {
+			return &ISPBlockingError{
+				Domain:      domain,
+				Reason:      bp.reason,
+				OriginalErr: err,
+			}
+		}
+	}
+
+	return nil
+}
+
+// CheckAndLogISPBlocking checks for ISP blocking and logs if detected
+// Returns true if ISP blocking was detected
+func CheckAndLogISPBlocking(err error, requestURL string, tag string) bool {
+	ispErr := IsISPBlocking(err, requestURL)
+	if ispErr != nil {
+		LogError(tag, "ISP BLOCKING DETECTED: %s", ispErr.Error())
+		LogError(tag, "Domain: %s", ispErr.Domain)
+		LogError(tag, "Reason: %s", ispErr.Reason)
+		LogError(tag, "Original error: %v", ispErr.OriginalErr)
+		LogError(tag, "Suggestion: Try using a VPN or changing your DNS to 1.1.1.1 or 8.8.8.8")
+		return true
+	}
+	return false
+}
+
+// extractDomain extracts the domain from a URL string
+func extractDomain(rawURL string) string {
+	if rawURL == "" {
+		return "unknown"
+	}
+	
+	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 {
+			return rawURL[:idx]
+		}
+		return rawURL
+	}
+	
+	if parsed.Host != "" {
+		return parsed.Host
+	}
+	return "unknown"
+}
+
+// WrapErrorWithISPCheck wraps an error with ISP blocking detection
+// If ISP blocking is detected, returns a more descriptive error
+func WrapErrorWithISPCheck(err error, requestURL string, tag string) error {
+	if err == nil {
+		return nil
+	}
+	
+	if CheckAndLogISPBlocking(err, requestURL, tag) {
+		domain := extractDomain(requestURL)
+		return fmt.Errorf("ISP blocking detected for %s - try using VPN or change DNS to 1.1.1.1/8.8.8.8: %w", domain, err)
+	}
+	
+	return err
+}

go_backend/logbuffer.go

@@ -0,0 +1,203 @@
+package gobackend
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+)
+
+// LogEntry represents a single log entry
+type LogEntry struct {
+	Timestamp string `json:"timestamp"`
+	Level     string `json:"level"`
+	Tag       string `json:"tag"`
+	Message   string `json:"message"`
+}
+
+// LogBuffer stores logs in a circular buffer for retrieval by Flutter
+type LogBuffer struct {
+	entries        []LogEntry
+	maxSize        int
+	mu             sync.RWMutex
+	loggingEnabled bool // Whether logging is enabled (controlled by Flutter)
+}
+
+var (
+	globalLogBuffer *LogBuffer
+	logBufferOnce   sync.Once
+)
+
+// GetLogBuffer returns the singleton log buffer instance
+func GetLogBuffer() *LogBuffer {
+	logBufferOnce.Do(func() {
+		globalLogBuffer = &LogBuffer{
+			entries:        make([]LogEntry, 0, 500),
+			maxSize:        500,
+			loggingEnabled: false, // Default: disabled for performance (user can enable in settings)
+		}
+	})
+	return globalLogBuffer
+}
+
+// SetLoggingEnabled enables or disables logging
+func (lb *LogBuffer) SetLoggingEnabled(enabled bool) {
+	lb.mu.Lock()
+	defer lb.mu.Unlock()
+	lb.loggingEnabled = enabled
+}
+
+// IsLoggingEnabled returns whether logging is enabled
+func (lb *LogBuffer) IsLoggingEnabled() bool {
+	lb.mu.RLock()
+	defer lb.mu.RUnlock()
+	return lb.loggingEnabled
+}
+
+// Add adds a log entry to the buffer
+func (lb *LogBuffer) Add(level, tag, message string) {
+	lb.mu.Lock()
+	defer lb.mu.Unlock()
+
+	// Skip if logging is disabled (except for errors which are always logged)
+	if !lb.loggingEnabled && level != "ERROR" && level != "FATAL" {
+		return
+	}
+
+	entry := LogEntry{
+		Timestamp: time.Now().Format("15:04:05.000"),
+		Level:     level,
+		Tag:       tag,
+		Message:   message,
+	}
+
+	if len(lb.entries) >= lb.maxSize {
+		// Remove oldest entry
+		lb.entries = lb.entries[1:]
+	}
+	lb.entries = append(lb.entries, entry)
+
+	// Also print to logcat for debugging
+	fmt.Printf("[%s] %s\n", tag, message)
+}
+
+// GetAll returns all log entries as JSON
+func (lb *LogBuffer) GetAll() string {
+	lb.mu.RLock()
+	defer lb.mu.RUnlock()
+
+	jsonBytes, _ := json.Marshal(lb.entries)
+	return string(jsonBytes)
+}
+
+// getSince returns log entries since the given index (internal use)
+func (lb *LogBuffer) getSince(index int) ([]LogEntry, int) {
+	lb.mu.RLock()
+	defer lb.mu.RUnlock()
+
+	if index < 0 {
+		index = 0
+	}
+	if index >= len(lb.entries) {
+		return []LogEntry{}, len(lb.entries)
+	}
+
+	entries := lb.entries[index:]
+	return entries, len(lb.entries)
+}
+
+// Clear clears all log entries
+func (lb *LogBuffer) Clear() {
+	lb.mu.Lock()
+	defer lb.mu.Unlock()
+	lb.entries = lb.entries[:0]
+}
+
+// Count returns the number of log entries
+func (lb *LogBuffer) Count() int {
+	lb.mu.RLock()
+	defer lb.mu.RUnlock()
+	return len(lb.entries)
+}
+
+// Helper functions for logging with different levels
+func LogDebug(tag, format string, args ...interface{}) {
+	GetLogBuffer().Add("DEBUG", tag, fmt.Sprintf(format, args...))
+}
+
+func LogInfo(tag, format string, args ...interface{}) {
+	GetLogBuffer().Add("INFO", tag, fmt.Sprintf(format, args...))
+}
+
+func LogWarn(tag, format string, args ...interface{}) {
+	GetLogBuffer().Add("WARN", tag, fmt.Sprintf(format, args...))
+}
+
+func LogError(tag, format string, args ...interface{}) {
+	GetLogBuffer().Add("ERROR", tag, fmt.Sprintf(format, args...))
+}
+
+// GoLog is a drop-in replacement for fmt.Printf that also logs to buffer
+// It parses the tag from the format string if it starts with [Tag]
+func GoLog(format string, args ...interface{}) {
+	message := fmt.Sprintf(format, args...)
+	message = strings.TrimSuffix(message, "\n")
+
+	// Extract tag from message if present (e.g., "[Tidal] message")
+	tag := "Go"
+	level := "INFO"
+
+	if strings.HasPrefix(message, "[") {
+		endBracket := strings.Index(message, "]")
+		if endBracket > 1 {
+			tag = message[1:endBracket]
+			message = strings.TrimSpace(message[endBracket+1:])
+		}
+	}
+
+	// Determine level from message content
+	msgLower := strings.ToLower(message)
+	if strings.Contains(msgLower, "error") || strings.Contains(msgLower, "failed") || strings.HasPrefix(message, "✗") {
+		level = "ERROR"
+	} else if strings.Contains(msgLower, "warning") || strings.Contains(msgLower, "warn") {
+		level = "WARN"
+	} else if strings.HasPrefix(message, "✓") || strings.Contains(msgLower, "success") || strings.Contains(msgLower, "match found") {
+		level = "INFO"
+	} else if strings.Contains(msgLower, "searching") || strings.Contains(msgLower, "trying") || strings.Contains(msgLower, "found") {
+		level = "DEBUG"
+	}
+
+	GetLogBuffer().Add(level, tag, message)
+}
+
+// Exported functions for Flutter
+
+// GetLogs returns all logs as JSON array
+func GetLogs() string {
+	return GetLogBuffer().GetAll()
+}
+
+// GetLogsSince returns logs since the given index
+// Returns JSON: {"logs": [...], "next_index": N}
+func GetLogsSince(index int) string {
+	entries, nextIndex := GetLogBuffer().getSince(index)
+	logsJson, _ := json.Marshal(entries)
+	result := fmt.Sprintf(`{"logs":%s,"next_index":%d}`, string(logsJson), nextIndex)
+	return result
+}
+
+// ClearLogs clears all logs
+func ClearLogs() {
+	GetLogBuffer().Clear()
+}
+
+// GetLogCount returns the number of log entries
+func GetLogCount() int {
+	return GetLogBuffer().Count()
+}
+
+// SetLoggingEnabled enables or disables logging from Flutter
+func SetLoggingEnabled(enabled bool) {
+	GetLogBuffer().SetLoggingEnabled(enabled)
+}

go_backend/lyrics.go

@@ -248,6 +248,8 @@ func msToLRCTimestamp(ms int64) string {
 	return fmt.Sprintf("[%02d:%02d.%02d]", minutes, seconds, centiseconds)
 }
 
+// convertToLRC converts lyrics to LRC format string (without metadata headers)
+// Use convertToLRCWithMetadata for full LRC with headers
 func convertToLRC(lyrics *LyricsResponse) string {
 	if lyrics == nil || len(lyrics.Lines) == 0 {
 		return ""
@@ -272,6 +274,45 @@ func convertToLRC(lyrics *LyricsResponse) string {
 	return builder.String()
 }
 
+// convertToLRCWithMetadata converts lyrics to LRC format with metadata headers
+// Includes [ti:], [ar:], [by:] headers
+func convertToLRCWithMetadata(lyrics *LyricsResponse, trackName, artistName string) string {
+	if lyrics == nil || len(lyrics.Lines) == 0 {
+		return ""
+	}
+
+	var builder strings.Builder
+
+	// Add metadata headers
+	builder.WriteString(fmt.Sprintf("[ti:%s]\n", trackName))
+	builder.WriteString(fmt.Sprintf("[ar:%s]\n", artistName))
+	builder.WriteString("[by:SpotiFLAC-Mobile]\n")
+	builder.WriteString("\n")
+
+	// Add lyrics lines
+	if lyrics.SyncType == "LINE_SYNCED" {
+		for _, line := range lyrics.Lines {
+			if line.Words == "" {
+				continue
+			}
+			timestamp := msToLRCTimestamp(line.StartTimeMs)
+			builder.WriteString(timestamp)
+			builder.WriteString(line.Words)
+			builder.WriteString("\n")
+		}
+	} else {
+		for _, line := range lyrics.Lines {
+			if line.Words == "" {
+				continue
+			}
+			builder.WriteString(line.Words)
+			builder.WriteString("\n")
+		}
+	}
+
+	return builder.String()
+}
+
 func simplifyTrackName(name string) string {
 	patterns := []string{
 		`\s*\(feat\..*?\)`,

go_backend/metadata.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 
 	"github.com/go-flac/flacpicture"
 	"github.com/go-flac/flacvorbis"
@@ -57,7 +58,7 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 	setComment(cmt, "ALBUM", metadata.Album)
 	setComment(cmt, "ALBUMARTIST", metadata.AlbumArtist)
 	setComment(cmt, "DATE", metadata.Date)
-	
+
 	if metadata.TrackNumber > 0 {
 		if metadata.TotalTracks > 0 {
 			setComment(cmt, "TRACKNUMBER", fmt.Sprintf("%d/%d", metadata.TrackNumber, metadata.TotalTracks))
@@ -65,15 +66,15 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 			setComment(cmt, "TRACKNUMBER", strconv.Itoa(metadata.TrackNumber))
 		}
 	}
-	
+
 	if metadata.DiscNumber > 0 {
 		setComment(cmt, "DISCNUMBER", strconv.Itoa(metadata.DiscNumber))
 	}
-	
+
 	if metadata.ISRC != "" {
 		setComment(cmt, "ISRC", metadata.ISRC)
 	}
-	
+
 	if metadata.Description != "" {
 		setComment(cmt, "DESCRIPTION", metadata.Description)
 	}
@@ -104,7 +105,7 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 						f.Meta = append(f.Meta[:i], f.Meta[i+1:]...)
 					}
 				}
-				
+
 				picture, err := flacpicture.NewFromImageData(
 					flacpicture.PictureTypeFrontCover,
 					"Front Cover",
@@ -161,7 +162,7 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 	setComment(cmt, "ALBUM", metadata.Album)
 	setComment(cmt, "ALBUMARTIST", metadata.AlbumArtist)
 	setComment(cmt, "DATE", metadata.Date)
-	
+
 	if metadata.TrackNumber > 0 {
 		if metadata.TotalTracks > 0 {
 			setComment(cmt, "TRACKNUMBER", fmt.Sprintf("%d/%d", metadata.TrackNumber, metadata.TotalTracks))
@@ -169,15 +170,15 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 			setComment(cmt, "TRACKNUMBER", strconv.Itoa(metadata.TrackNumber))
 		}
 	}
-	
+
 	if metadata.DiscNumber > 0 {
 		setComment(cmt, "DISCNUMBER", strconv.Itoa(metadata.DiscNumber))
 	}
-	
+
 	if metadata.ISRC != "" {
 		setComment(cmt, "ISRC", metadata.ISRC)
 	}
-	
+
 	if metadata.Description != "" {
 		setComment(cmt, "DESCRIPTION", metadata.Description)
 	}
@@ -203,7 +204,7 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 				f.Meta = append(f.Meta[:i], f.Meta[i+1:]...)
 			}
 		}
-		
+
 		picture, err := flacpicture.NewFromImageData(
 			flacpicture.PictureTypeFrontCover,
 			"Front Cover",
@@ -256,11 +257,30 @@ func ReadMetadata(filePath string) (*Metadata, error) {
 			if trackNum != "" {
 				fmt.Sscanf(trackNum, "%d", &metadata.TrackNumber)
 			}
+			// Also try lowercase variant (some encoders use lowercase)
+			if metadata.TrackNumber == 0 {
+				trackNum = getComment(cmt, "TRACK")
+				if trackNum != "" {
+					fmt.Sscanf(trackNum, "%d", &metadata.TrackNumber)
+				}
+			}
 
 			discNum := getComment(cmt, "DISCNUMBER")
 			if discNum != "" {
 				fmt.Sscanf(discNum, "%d", &metadata.DiscNumber)
 			}
+			// Also try DISC variant
+			if metadata.DiscNumber == 0 {
+				discNum = getComment(cmt, "DISC")
+				if discNum != "" {
+					fmt.Sscanf(discNum, "%d", &metadata.DiscNumber)
+				}
+			}
+
+			// Try DATE variants
+			if metadata.Date == "" {
+				metadata.Date = getComment(cmt, "YEAR")
+			}
 
 			break
 		}
@@ -273,10 +293,16 @@ func setComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key, value string) {
 	if value == "" {
 		return
 	}
-	// Remove existing
+	// Remove existing (case-insensitive comparison for Vorbis comments)
+	keyUpper := strings.ToUpper(key)
 	for i := len(cmt.Comments) - 1; i >= 0; i-- {
-		if len(cmt.Comments[i]) > len(key)+1 && cmt.Comments[i][:len(key)+1] == key+"=" {
-			cmt.Comments = append(cmt.Comments[:i], cmt.Comments[i+1:]...)
+		comment := cmt.Comments[i]
+		eqIdx := strings.Index(comment, "=")
+		if eqIdx > 0 {
+			existingKey := strings.ToUpper(comment[:eqIdx])
+			if existingKey == keyUpper {
+				cmt.Comments = append(cmt.Comments[:i], cmt.Comments[i+1:]...)
+			}
 		}
 	}
 	// Add new
@@ -284,9 +310,14 @@ func setComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key, value string) {
 }
 
 func getComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key string) string {
+	keyUpper := strings.ToUpper(key) + "="
 	for _, comment := range cmt.Comments {
-		if len(comment) > len(key)+1 && comment[:len(key)+1] == key+"=" {
-			return comment[len(key)+1:]
+		if len(comment) > len(key) {
+			// Case-insensitive comparison for Vorbis comments
+			commentUpper := strings.ToUpper(comment[:len(key)+1])
+			if commentUpper == keyUpper {
+				return comment[len(key)+1:]
+			}
 		}
 	}
 	return ""
@@ -335,3 +366,457 @@ func EmbedLyrics(filePath string, lyrics 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 {
+		return "", fmt.Errorf("failed to parse FLAC file: %w", err)
+	}
+
+	for _, meta := range f.Meta {
+		if meta.Type == flac.VorbisComment {
+			cmt, err := flacvorbis.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				continue
+			}
+
+			// Try LYRICS tag first
+			lyrics, err := cmt.Get("LYRICS")
+			if err == nil && len(lyrics) > 0 && lyrics[0] != "" {
+				return lyrics[0], nil
+			}
+
+			// Fallback to UNSYNCEDLYRICS
+			lyrics, err = cmt.Get("UNSYNCEDLYRICS")
+			if err == nil && len(lyrics) > 0 && lyrics[0] != "" {
+				return lyrics[0], nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("no lyrics found in file")
+}
+
+// AudioQuality represents audio quality info from a FLAC file
+type AudioQuality struct {
+	BitDepth     int   `json:"bit_depth"`
+	SampleRate   int   `json:"sample_rate"`
+	TotalSamples int64 `json:"total_samples"`
+}
+
+// GetAudioQuality reads bit depth and sample rate from a FLAC file's StreamInfo block
+// FLAC StreamInfo is always the first metadata block after the 4-byte "fLaC" marker
+// For M4A files, it delegates to GetM4AQuality
+func GetAudioQuality(filePath string) (AudioQuality, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	// Read first 4 bytes to detect file type
+	marker := make([]byte, 4)
+	if _, err := file.Read(marker); err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to read marker: %w", err)
+	}
+
+	// Check if it's a FLAC file
+	if string(marker) == "fLaC" {
+		// Continue reading FLAC metadata
+		// Read metadata block header (4 bytes)
+		header := make([]byte, 4)
+		if _, err := file.Read(header); err != nil {
+			return AudioQuality{}, fmt.Errorf("failed to read header: %w", err)
+		}
+
+		blockType := header[0] & 0x7F
+		if blockType != 0 {
+			return AudioQuality{}, fmt.Errorf("first block is not STREAMINFO")
+		}
+
+		// Read STREAMINFO block (34 bytes minimum)
+		streamInfo := make([]byte, 34)
+		if _, err := file.Read(streamInfo); err != nil {
+			return AudioQuality{}, fmt.Errorf("failed to read STREAMINFO: %w", err)
+		}
+
+		// Parse sample rate (20 bits starting at byte 10)
+		sampleRate := (int(streamInfo[10]) << 12) | (int(streamInfo[11]) << 4) | (int(streamInfo[12]) >> 4)
+
+		// Parse bits per sample (5 bits)
+		bitsPerSample := ((int(streamInfo[12]) & 0x01) << 4) | (int(streamInfo[13]) >> 4) + 1
+
+		// Parse total samples (36 bits: 4 bits from byte 13, all of bytes 14-17)
+		totalSamples := int64(streamInfo[13]&0x0F)<<32 |
+			int64(streamInfo[14])<<24 |
+			int64(streamInfo[15])<<16 |
+			int64(streamInfo[16])<<8 |
+			int64(streamInfo[17])
+
+		return AudioQuality{
+			BitDepth:     bitsPerSample,
+			SampleRate:   sampleRate,
+			TotalSamples: totalSamples,
+		}, nil
+	}
+
+	// Check if it's an M4A/MP4 file (starts with size + "ftyp")
+	// First 4 bytes are size, next 4 should be "ftyp"
+	file.Seek(0, 0) // Reset to beginning
+	header8 := make([]byte, 8)
+	if _, err := file.Read(header8); err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to read header: %w", err)
+	}
+
+	if string(header8[4:8]) == "ftyp" {
+		// It's an M4A/MP4 file, use M4A quality reader
+		file.Close() // Close before calling GetM4AQuality which opens the file again
+		return GetM4AQuality(filePath)
+	}
+
+	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
+// This is a simplified implementation that writes metadata to the file
+func EmbedM4AMetadata(filePath string, metadata Metadata, coverData []byte) error {
+	// Read the entire file
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to read M4A file: %w", err)
+	}
+
+	// Find moov atom position
+	moovPos := findAtom(data, "moov", 0)
+	if moovPos < 0 {
+		return fmt.Errorf("moov atom not found in M4A file")
+	}
+
+	// Find udta atom inside moov, or create one
+	moovSize := int(data[moovPos]<<24 | data[moovPos+1]<<16 | data[moovPos+2]<<8 | data[moovPos+3])
+	udtaPos := findAtom(data, "udta", moovPos+8)
+
+	// Build new metadata atoms
+	metaAtom := buildMetaAtom(metadata, coverData)
+
+	var newData []byte
+	if udtaPos >= 0 && udtaPos < moovPos+moovSize {
+		// udta exists, find meta inside it or replace
+		udtaSize := int(data[udtaPos]<<24 | data[udtaPos+1]<<16 | data[udtaPos+2]<<8 | data[udtaPos+3])
+		metaPos := findAtom(data, "meta", udtaPos+8)
+
+		if metaPos >= 0 && metaPos < udtaPos+udtaSize {
+			// Replace existing meta atom
+			metaSize := int(data[metaPos]<<24 | data[metaPos+1]<<16 | data[metaPos+2]<<8 | data[metaPos+3])
+			newData = append(newData, data[:metaPos]...)
+			newData = append(newData, metaAtom...)
+			newData = append(newData, data[metaPos+metaSize:]...)
+		} else {
+			// Add meta atom to udta
+			newUdtaContent := append(data[udtaPos+8:udtaPos+udtaSize], metaAtom...)
+			newUdtaSize := 8 + len(newUdtaContent)
+			newUdta := make([]byte, 4)
+			newUdta[0] = byte(newUdtaSize >> 24)
+			newUdta[1] = byte(newUdtaSize >> 16)
+			newUdta[2] = byte(newUdtaSize >> 8)
+			newUdta[3] = byte(newUdtaSize)
+			newUdta = append(newUdta, []byte("udta")...)
+			newUdta = append(newUdta, newUdtaContent...)
+
+			newData = append(newData, data[:udtaPos]...)
+			newData = append(newData, newUdta...)
+			newData = append(newData, data[udtaPos+udtaSize:]...)
+		}
+	} else {
+		// Create new udta with meta
+		udtaContent := metaAtom
+		udtaSize := 8 + len(udtaContent)
+		newUdta := make([]byte, 4)
+		newUdta[0] = byte(udtaSize >> 24)
+		newUdta[1] = byte(udtaSize >> 16)
+		newUdta[2] = byte(udtaSize >> 8)
+		newUdta[3] = byte(udtaSize)
+		newUdta = append(newUdta, []byte("udta")...)
+		newUdta = append(newUdta, udtaContent...)
+
+		// Insert udta at end of moov
+		insertPos := moovPos + moovSize
+		newData = append(newData, data[:insertPos]...)
+		newData = append(newData, newUdta...)
+		newData = append(newData, data[insertPos:]...)
+	}
+
+	// Update moov size
+	newMoovSize := moovSize + len(newData) - len(data)
+	newData[moovPos] = byte(newMoovSize >> 24)
+	newData[moovPos+1] = byte(newMoovSize >> 16)
+	newData[moovPos+2] = byte(newMoovSize >> 8)
+	newData[moovPos+3] = byte(newMoovSize)
+
+	// Write back to file
+	if err := os.WriteFile(filePath, newData, 0644); err != nil {
+		return fmt.Errorf("failed to write M4A file: %w", err)
+	}
+
+	fmt.Printf("[M4A] Metadata embedded successfully\n")
+	return nil
+}
+
+// findAtom finds an atom by name starting from offset
+func findAtom(data []byte, name string, offset int) int {
+	for i := offset; i < len(data)-8; {
+		size := int(data[i]<<24 | data[i+1]<<16 | data[i+2]<<8 | data[i+3])
+		if size < 8 {
+			break
+		}
+		atomName := string(data[i+4 : i+8])
+		if atomName == name {
+			return i
+		}
+		i += size
+	}
+	return -1
+}
+
+// buildMetaAtom builds a complete meta atom with ilst containing metadata
+func buildMetaAtom(metadata Metadata, coverData []byte) []byte {
+	// Build ilst content
+	var ilst []byte
+
+	// ©nam - Title
+	if metadata.Title != "" {
+		ilst = append(ilst, buildTextAtom("©nam", metadata.Title)...)
+	}
+
+	// ©ART - Artist
+	if metadata.Artist != "" {
+		ilst = append(ilst, buildTextAtom("©ART", metadata.Artist)...)
+	}
+
+	// ©alb - Album
+	if metadata.Album != "" {
+		ilst = append(ilst, buildTextAtom("©alb", metadata.Album)...)
+	}
+
+	// aART - Album Artist
+	if metadata.AlbumArtist != "" {
+		ilst = append(ilst, buildTextAtom("aART", metadata.AlbumArtist)...)
+	}
+
+	// ©day - Year/Date
+	if metadata.Date != "" {
+		ilst = append(ilst, buildTextAtom("©day", metadata.Date)...)
+	}
+
+	// trkn - Track Number
+	if metadata.TrackNumber > 0 {
+		ilst = append(ilst, buildTrackNumberAtom(metadata.TrackNumber, metadata.TotalTracks)...)
+	}
+
+	// disk - Disc Number
+	if metadata.DiscNumber > 0 {
+		ilst = append(ilst, buildDiscNumberAtom(metadata.DiscNumber, 0)...)
+	}
+
+	// ©lyr - Lyrics
+	if metadata.Lyrics != "" {
+		ilst = append(ilst, buildTextAtom("©lyr", metadata.Lyrics)...)
+	}
+
+	// covr - Cover Art
+	if len(coverData) > 0 {
+		ilst = append(ilst, buildCoverAtom(coverData)...)
+	}
+
+	// Build ilst atom
+	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...)
+
+	// Build hdlr atom (required for meta)
+	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
+	}
+
+	// Build meta atom
+	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
+}
+
+// buildTextAtom builds a text metadata atom (©nam, ©ART, etc.)
+func buildTextAtom(name, value string) []byte {
+	valueBytes := []byte(value)
+
+	// data atom
+	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...)
+
+	// container atom
+	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 {
+	// data atom with track number
+	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
+	}
+
+	// trkn atom
+	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
+}
+
+// buildDiscNumberAtom builds disk atom
+func buildDiscNumberAtom(disc, total int) []byte {
+	// data atom with disc number
+	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
+	}
+
+	// disk atom
+	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 {
+	// Detect image type (JPEG = 13, PNG = 14)
+	imageType := byte(13) // default JPEG
+	if len(coverData) > 8 && coverData[0] == 0x89 && coverData[1] == 'P' && coverData[2] == 'N' && coverData[3] == 'G' {
+		imageType = 14 // PNG
+	}
+
+	// data atom
+	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) // type = JPEG or PNG
+	dataAtom = append(dataAtom, 0, 0, 0, 0)         // locale
+	dataAtom = append(dataAtom, coverData...)
+
+	// covr atom
+	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
+}
+
+// GetM4AQuality reads audio quality from M4A file
+func GetM4AQuality(filePath string) (AudioQuality, error) {
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to read M4A file: %w", err)
+	}
+
+	// Find moov -> trak -> mdia -> minf -> stbl -> stsd
+	moovPos := findAtom(data, "moov", 0)
+	if moovPos < 0 {
+		return AudioQuality{}, fmt.Errorf("moov atom not found")
+	}
+
+	// Search for mp4a or alac atom which contains audio info
+	// This is a simplified search - real implementation would traverse the atom tree
+	for i := moovPos; i < len(data)-20; i++ {
+		if string(data[i:i+4]) == "mp4a" || string(data[i:i+4]) == "alac" {
+			// Sample rate is at offset 22-23 from atom start (16-bit big-endian)
+			if i+24 < len(data) {
+				sampleRate := int(data[i+22])<<8 | int(data[i+23])
+				// For AAC, bit depth is typically 16
+				bitDepth := 16
+				if string(data[i:i+4]) == "alac" {
+					// ALAC can have higher bit depth, check esds or alac specific data
+					bitDepth = 24 // Assume 24-bit for ALAC
+				}
+				return AudioQuality{BitDepth: bitDepth, SampleRate: sampleRate}, nil
+			}
+		}
+	}
+
+	return AudioQuality{}, fmt.Errorf("audio info not found in M4A file")
+}

go_backend/parallel.go

@@ -0,0 +1,289 @@
+package gobackend
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+// ========================================
+// ISRC to Track ID Cache
+// ========================================
+
+// TrackIDCacheEntry holds cached track ID with metadata
+type TrackIDCacheEntry struct {
+	TidalTrackID  int64
+	QobuzTrackID  int64
+	AmazonTrackID string
+	ExpiresAt     time.Time
+}
+
+// TrackIDCache caches ISRC to track ID mappings
+type TrackIDCache struct {
+	cache map[string]*TrackIDCacheEntry
+	mu    sync.RWMutex
+	ttl   time.Duration
+}
+
+var (
+	globalTrackIDCache *TrackIDCache
+	trackIDCacheOnce   sync.Once
+)
+
+// GetTrackIDCache returns the global track ID cache
+func GetTrackIDCache() *TrackIDCache {
+	trackIDCacheOnce.Do(func() {
+		globalTrackIDCache = &TrackIDCache{
+			cache: make(map[string]*TrackIDCacheEntry),
+			ttl:   30 * time.Minute, // Cache for 30 minutes
+		}
+	})
+	return globalTrackIDCache
+}
+
+// Get retrieves a cached entry by ISRC
+func (c *TrackIDCache) Get(isrc string) *TrackIDCacheEntry {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	entry, exists := c.cache[isrc]
+	if !exists || time.Now().After(entry.ExpiresAt) {
+		return nil
+	}
+	return entry
+}
+
+// SetTidal caches Tidal track ID for an ISRC
+func (c *TrackIDCache) SetTidal(isrc string, trackID int64) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	entry, exists := c.cache[isrc]
+	if !exists {
+		entry = &TrackIDCacheEntry{}
+		c.cache[isrc] = entry
+	}
+	entry.TidalTrackID = trackID
+	entry.ExpiresAt = time.Now().Add(c.ttl)
+}
+
+// SetQobuz caches Qobuz track ID for an ISRC
+func (c *TrackIDCache) SetQobuz(isrc string, trackID int64) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	entry, exists := c.cache[isrc]
+	if !exists {
+		entry = &TrackIDCacheEntry{}
+		c.cache[isrc] = entry
+	}
+	entry.QobuzTrackID = trackID
+	entry.ExpiresAt = time.Now().Add(c.ttl)
+}
+
+// SetAmazon caches Amazon track ID for an ISRC
+func (c *TrackIDCache) SetAmazon(isrc string, trackID string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	entry, exists := c.cache[isrc]
+	if !exists {
+		entry = &TrackIDCacheEntry{}
+		c.cache[isrc] = entry
+	}
+	entry.AmazonTrackID = trackID
+	entry.ExpiresAt = time.Now().Add(c.ttl)
+}
+
+// Clear removes all cached entries
+func (c *TrackIDCache) Clear() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.cache = make(map[string]*TrackIDCacheEntry)
+}
+
+// Size returns the number of cached entries
+func (c *TrackIDCache) Size() int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return len(c.cache)
+}
+
+// ========================================
+// Parallel Download Helper
+// ========================================
+
+// ParallelDownloadResult holds results from parallel operations
+type ParallelDownloadResult struct {
+	CoverData  []byte
+	LyricsData *LyricsResponse
+	LyricsLRC  string
+	CoverErr   error
+	LyricsErr  error
+}
+
+// FetchCoverAndLyricsParallel downloads cover and fetches lyrics in parallel
+// This runs while the main audio download is happening
+func FetchCoverAndLyricsParallel(
+	coverURL string,
+	maxQualityCover bool,
+	spotifyID string,
+	trackName string,
+	artistName string,
+	embedLyrics bool,
+) *ParallelDownloadResult {
+	result := &ParallelDownloadResult{}
+	var wg sync.WaitGroup
+
+	// Download cover in parallel
+	if coverURL != "" {
+		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))
+			}
+		}()
+	}
+
+	// Fetch lyrics in parallel
+	if embedLyrics {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			fmt.Println("[Parallel] Starting lyrics fetch...")
+			client := NewLyricsClient()
+			lyrics, err := client.FetchLyricsAllSources(spotifyID, trackName, artistName)
+			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
+				// Use LRC with metadata headers (like PC version)
+				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")
+			}
+		}()
+	}
+
+	wg.Wait()
+	return result
+}
+
+// ========================================
+// Pre-warm Cache for Album/Playlist
+// ========================================
+
+// PreWarmCacheRequest represents a track to pre-warm cache for
+type PreWarmCacheRequest struct {
+	ISRC       string
+	TrackName  string
+	ArtistName string
+	SpotifyID  string // Needed for Amazon (SongLink lookup)
+	Service    string // "tidal", "qobuz", "amazon"
+}
+
+// PreWarmTrackCache pre-fetches track IDs for multiple tracks (for album/playlist)
+// This runs in background while user is viewing the track list
+func PreWarmTrackCache(requests []PreWarmCacheRequest) {
+	if len(requests) == 0 {
+		return
+	}
+
+	fmt.Printf("[Cache] Pre-warming cache for %d tracks...\n", len(requests))
+	cache := GetTrackIDCache()
+
+	// Limit concurrent pre-warm requests
+	semaphore := make(chan struct{}, 3) // Max 3 concurrent
+	var wg sync.WaitGroup
+
+	for _, req := range requests {
+		// Skip if already cached
+		if cached := cache.Get(req.ISRC); cached != nil {
+			continue
+		}
+
+		wg.Add(1)
+		go func(r PreWarmCacheRequest) {
+			defer wg.Done()
+			semaphore <- struct{}{}        // Acquire
+			defer func() { <-semaphore }() // Release
+
+			switch r.Service {
+			case "tidal":
+				preWarmTidalCache(r.ISRC, r.TrackName, r.ArtistName)
+			case "qobuz":
+				preWarmQobuzCache(r.ISRC)
+			case "amazon":
+				preWarmAmazonCache(r.ISRC, r.SpotifyID)
+			}
+		}(req)
+	}
+
+	wg.Wait()
+	fmt.Printf("[Cache] Pre-warm complete. Cache size: %d\n", cache.Size())
+}
+
+func preWarmTidalCache(isrc, trackName, artistName string) {
+	downloader := NewTidalDownloader()
+	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)
+	}
+}
+
+func preWarmQobuzCache(isrc string) {
+	downloader := NewQobuzDownloader()
+	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)
+	}
+}
+
+func preWarmAmazonCache(isrc, spotifyID string) {
+	// Amazon uses SongLink to get URL, so we pre-warm by checking availability
+	client := NewSongLinkClient()
+	availability, err := client.CheckTrackAvailability(spotifyID, isrc)
+	if err == nil && availability != nil && availability.Amazon {
+		// Store Amazon URL in cache (using ISRC as key)
+		GetTrackIDCache().SetAmazon(isrc, availability.AmazonURL)
+		fmt.Printf("[Cache] Cached Amazon URL for ISRC %s\n", isrc)
+	}
+}
+
+// ========================================
+// Exported Functions for Flutter
+// ========================================
+
+// PreWarmCache is called from Flutter to pre-warm cache for album/playlist tracks
+// tracksJSON is a JSON array of {isrc, track_name, artist_name, service}
+func PreWarmCache(tracksJSON string) error {
+	var requests []PreWarmCacheRequest
+	// Parse JSON (simplified - in production use proper JSON parsing)
+	// For now, this is called from exports.go with proper parsing
+	
+	go PreWarmTrackCache(requests) // Run in background
+	return nil
+}
+
+// ClearTrackCache clears the track ID cache
+func ClearTrackCache() {
+	GetTrackIDCache().Clear()
+	fmt.Println("[Cache] Track ID cache cleared")
+}
+
+// GetCacheSize returns the current cache size
+func GetCacheSize() int {
+	return GetTrackIDCache().Size()
+}

go_backend/progress.go

@@ -1,10 +1,13 @@
 package gobackend
 
 import (
+	"encoding/json"
 	"sync"
+	"time"
 )
 
 // DownloadProgress represents current download progress
+// Now unified - returns data from multi-progress system
 type DownloadProgress struct {
 	CurrentFile   string  `json:"current_file"`
 	Progress      float64 `json:"progress"`
@@ -12,54 +15,184 @@ type DownloadProgress struct {
 	BytesTotal    int64   `json:"bytes_total"`
 	BytesReceived int64   `json:"bytes_received"`
 	IsDownloading bool    `json:"is_downloading"`
+	Status        string  `json:"status"` // "downloading", "finalizing", "completed"
+}
+
+// ItemProgress represents progress for a single download item
+type ItemProgress struct {
+	ItemID        string  `json:"item_id"`
+	BytesTotal    int64   `json:"bytes_total"`
+	BytesReceived int64   `json:"bytes_received"`
+	Progress      float64 `json:"progress"` // 0.0 to 1.0
+	SpeedMBps     float64 `json:"speed_mbps"` // Download speed in MB/s
+	IsDownloading bool    `json:"is_downloading"`
+	Status        string  `json:"status"` // "downloading", "finalizing", "completed"
+}
+
+// MultiProgress holds progress for multiple concurrent downloads
+type MultiProgress struct {
+	Items map[string]*ItemProgress `json:"items"`
 }
 
 var (
-	currentProgress DownloadProgress
-	progressMu      sync.RWMutex
-	downloadDir     string
-	downloadDirMu   sync.RWMutex
+	downloadDir   string
+	downloadDirMu sync.RWMutex
+
+	// Multi-download progress tracking (unified system)
+	multiProgress = MultiProgress{Items: make(map[string]*ItemProgress)}
+	multiMu       sync.RWMutex
 )
 
-// getProgress returns current download progress
+// getProgress returns current download progress from multi-progress system
+// Returns first active item's progress for backward compatibility
 func getProgress() DownloadProgress {
-	progressMu.RLock()
-	defer progressMu.RUnlock()
-	return currentProgress
+	multiMu.RLock()
+	defer multiMu.RUnlock()
+
+	// Find first active item
+	for _, item := range multiProgress.Items {
+		return DownloadProgress{
+			CurrentFile:   item.ItemID,
+			Progress:      item.Progress * 100, // Convert to percentage
+			BytesTotal:    item.BytesTotal,
+			BytesReceived: item.BytesReceived,
+			IsDownloading: item.IsDownloading,
+			Status:        item.Status,
+		}
+	}
+
+	return DownloadProgress{}
 }
 
-// SetDownloadProgress sets the current download progress (MB downloaded)
-func SetDownloadProgress(mbDownloaded float64) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress.Progress = mbDownloaded
-	currentProgress.IsDownloading = true
+// GetMultiProgress returns progress for all active downloads as JSON
+func GetMultiProgress() string {
+	multiMu.RLock()
+	defer multiMu.RUnlock()
+
+	jsonBytes, err := json.Marshal(multiProgress)
+	if err != nil {
+		return "{\"items\":{}}"
+	}
+	return string(jsonBytes)
 }
 
-// SetDownloadSpeed sets the current download speed
-func SetDownloadSpeed(speedMBps float64) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress.Speed = speedMBps
+// GetItemProgress returns progress for a specific item as JSON
+func GetItemProgress(itemID string) string {
+	multiMu.RLock()
+	defer multiMu.RUnlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		jsonBytes, _ := json.Marshal(item)
+		return string(jsonBytes)
+	}
+	return "{}"
 }
 
-// SetCurrentFile sets the current file being downloaded and resets progress
-func SetCurrentFile(filename string) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	// Reset progress for new file
-	currentProgress.BytesReceived = 0
-	currentProgress.BytesTotal = 0
-	currentProgress.Progress = 0
-	currentProgress.CurrentFile = filename
-	currentProgress.IsDownloading = true
+// StartItemProgress initializes progress tracking for an item
+func StartItemProgress(itemID string) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	multiProgress.Items[itemID] = &ItemProgress{
+		ItemID:        itemID,
+		BytesTotal:    0,
+		BytesReceived: 0,
+		Progress:      0,
+		IsDownloading: true,
+		Status:        "downloading",
+	}
 }
 
-// ResetProgress resets the download progress
-func ResetProgress() {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress = DownloadProgress{}
+// SetItemBytesTotal sets total bytes for an item
+func SetItemBytesTotal(itemID string, total int64) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.BytesTotal = total
+	}
+}
+
+// SetItemBytesReceived sets bytes received for an item
+func SetItemBytesReceived(itemID string, received int64) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.BytesReceived = received
+		if item.BytesTotal > 0 {
+			item.Progress = float64(received) / float64(item.BytesTotal)
+		}
+	}
+}
+
+// SetItemBytesReceivedWithSpeed sets bytes received and speed for an item
+func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps float64) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.BytesReceived = received
+		item.SpeedMBps = speedMBps
+		if item.BytesTotal > 0 {
+			item.Progress = float64(received) / float64(item.BytesTotal)
+		}
+	}
+}
+
+// CompleteItemProgress marks an item as complete
+func CompleteItemProgress(itemID string) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.Progress = 1.0
+		item.IsDownloading = false
+		item.Status = "completed"
+	}
+}
+
+// SetItemProgress sets progress for an item directly
+func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal int64) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.Progress = progress
+		if bytesReceived > 0 {
+			item.BytesReceived = bytesReceived
+		}
+		if bytesTotal > 0 {
+			item.BytesTotal = bytesTotal
+		}
+	}
+}
+
+// SetItemFinalizing marks an item as finalizing (embedding metadata)
+func SetItemFinalizing(itemID string) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	if item, ok := multiProgress.Items[itemID]; ok {
+		item.Progress = 1.0
+		item.Status = "finalizing"
+	}
+}
+
+// RemoveItemProgress removes progress tracking for an item
+func RemoveItemProgress(itemID string) {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	delete(multiProgress.Items, itemID)
+}
+
+// ClearAllItemProgress clears all item progress
+func ClearAllItemProgress() {
+	multiMu.Lock()
+	defer multiMu.Unlock()
+
+	multiProgress.Items = make(map[string]*ItemProgress)
 }
 
 // setDownloadDir sets the default download directory
@@ -77,61 +210,57 @@ func getDownloadDir() string {
 	return downloadDir
 }
 
-// SetDownloading sets the download status
-func SetDownloading(status bool) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress.IsDownloading = status
+// ItemProgressWriter wraps io.Writer to track download progress for a specific item
+type ItemProgressWriter struct {
+	writer       interface{ Write([]byte) (int, error) }
+	itemID       string
+	current      int64
+	lastReported int64     // Track last reported bytes for threshold-based updates
+	startTime    time.Time // Track start time for speed calculation
+	lastTime     time.Time // Track last update time for speed calculation
+	lastBytes    int64     // Track bytes at last speed calculation
 }
 
-// SetBytesTotal sets total bytes to download
-func SetBytesTotal(total int64) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress.BytesTotal = total
-}
+const progressUpdateThreshold = 64 * 1024 // Update progress every 64KB
 
-// SetBytesReceived sets bytes received so far
-func SetBytesReceived(received int64) {
-	progressMu.Lock()
-	defer progressMu.Unlock()
-	currentProgress.BytesReceived = received
-	if currentProgress.BytesTotal > 0 {
-		currentProgress.Progress = float64(received) / float64(currentProgress.BytesTotal) * 100
+// 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{
+		writer:       w,
+		itemID:       itemID,
+		current:      0,
+		lastReported: 0,
+		startTime:    now,
+		lastTime:     now,
+		lastBytes:    0,
 	}
 }
 
-// ProgressWriter wraps io.Writer to track download progress
-type ProgressWriter struct {
-	writer  interface{ Write([]byte) (int, error) }
-	total   int64
-	current int64
-}
-
-// NewProgressWriter creates a new progress writer wrapping an io.Writer
-func NewProgressWriter(w interface{ Write([]byte) (int, error) }) *ProgressWriter {
-	// Reset bytes received when starting new download
-	SetBytesReceived(0)
-	return &ProgressWriter{
-		writer:  w,
-		current: 0,
-		total:   0,
-	}
-}
-
-// Write implements io.Writer
-func (pw *ProgressWriter) Write(p []byte) (int, error) {
+// Write implements io.Writer with threshold-based progress updates and speed tracking
+func (pw *ItemProgressWriter) Write(p []byte) (int, error) {
 	n, err := pw.writer.Write(p)
 	if err != nil {
 		return n, err
 	}
 	pw.current += int64(n)
-	pw.total += int64(n)
-	SetBytesReceived(pw.current)
+
+	// Update progress when we've received at least 64KB since last update
+	// Also update on first write to show download has started
+	if pw.lastReported == 0 || pw.current-pw.lastReported >= progressUpdateThreshold {
+		// Calculate speed (MB/s) based on bytes received since last update
+		now := time.Now()
+		elapsed := now.Sub(pw.lastTime).Seconds()
+		var speedMBps float64
+		if elapsed > 0 {
+			bytesInInterval := pw.current - pw.lastBytes
+			speedMBps = float64(bytesInInterval) / (1024 * 1024) / elapsed
+		}
+		
+		SetItemBytesReceivedWithSpeed(pw.itemID, pw.current, speedMBps)
+		pw.lastReported = pw.current
+		pw.lastTime = now
+		pw.lastBytes = pw.current
+	}
 	return n, nil
 }
-
-// GetTotal returns total bytes written
-func (pw *ProgressWriter) GetTotal() int64 {
-	return pw.total
-}

go_backend/qobuz.go

@@ -1,6 +1,7 @@
 package gobackend
 
 import (
+	"bufio"
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
@@ -9,6 +10,8 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"strings"
+	"sync"
 )
 
 // QobuzDownloader handles Qobuz downloads
@@ -18,6 +21,12 @@ type QobuzDownloader struct {
 	apiURL string
 }
 
+var (
+	// Global Qobuz downloader instance for connection reuse
+	globalQobuzDownloader *QobuzDownloader
+	qobuzDownloaderOnce   sync.Once
+)
+
 // QobuzTrack represents a Qobuz track
 type QobuzTrack struct {
 	ID                  int64   `json:"id"`
@@ -39,12 +48,257 @@ type QobuzTrack struct {
 	} `json:"performer"`
 }
 
-// NewQobuzDownloader creates a new Qobuz downloader
-func NewQobuzDownloader() *QobuzDownloader {
-	return &QobuzDownloader{
-		client: NewHTTPClientWithTimeout(DefaultTimeout), // 60s timeout
-		appID:  "798273057",
+// qobuzArtistsMatch checks if the artist names are similar enough
+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
+	}
+
+	// Check first artist (before comma or feat)
+	expectedFirst := strings.Split(normExpected, ",")[0]
+	expectedFirst = strings.Split(expectedFirst, " feat")[0]
+	expectedFirst = strings.Split(expectedFirst, " ft.")[0]
+	expectedFirst = strings.TrimSpace(expectedFirst)
+
+	foundFirst := strings.Split(normFound, ",")[0]
+	foundFirst = strings.Split(foundFirst, " feat")[0]
+	foundFirst = strings.Split(foundFirst, " ft.")[0]
+	foundFirst = strings.TrimSpace(foundFirst)
+
+	if expectedFirst == foundFirst {
+		return true
+	}
+
+	// Check if first artist is contained in the other
+	if strings.Contains(expectedFirst, foundFirst) || strings.Contains(foundFirst, expectedFirst) {
+		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(expectedArtist)
+	foundLatin := qobuzIsLatinScript(foundArtist)
+	if expectedLatin != foundLatin {
+		GoLog("[Qobuz] Artist names in different scripts, assuming match: '%s' vs '%s'\n", expectedArtist, foundArtist)
+		return true
+	}
+
+	return false
+}
+
+// qobuzTitlesMatch checks if track titles are similar enough
+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
+	}
+
+	// Check if one contains the other
+	if strings.Contains(normExpected, normFound) || strings.Contains(normFound, normExpected) {
+		return true
+	}
+
+	// Clean BOTH titles and compare (removes suffixes like remaster, remix, etc)
+	cleanExpected := qobuzCleanTitle(normExpected)
+	cleanFound := qobuzCleanTitle(normFound)
+
+	if cleanExpected == cleanFound {
+		return true
+	}
+
+	// Check if cleaned versions contain each other
+	if cleanExpected != "" && cleanFound != "" {
+		if strings.Contains(cleanExpected, cleanFound) || strings.Contains(cleanFound, cleanExpected) {
+			return true
+		}
+	}
+
+	// Extract core title (before any parentheses/brackets)
+	coreExpected := qobuzExtractCoreTitle(normExpected)
+	coreFound := qobuzExtractCoreTitle(normFound)
+
+	if coreExpected != "" && coreFound != "" && coreExpected == coreFound {
+		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 {
+		GoLog("[Qobuz] Titles in different scripts, assuming match: '%s' vs '%s'\n", expectedTitle, foundTitle)
+		return true
+	}
+
+	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, " - ")
+
+	cutIdx := len(title)
+	if parenIdx > 0 && parenIdx < cutIdx {
+		cutIdx = parenIdx
+	}
+	if bracketIdx > 0 && bracketIdx < cutIdx {
+		cutIdx = bracketIdx
+	}
+	if dashIdx > 0 && dashIdx < cutIdx {
+		cutIdx = dashIdx
+	}
+
+	return strings.TrimSpace(title[:cutIdx])
+}
+
+// qobuzCleanTitle removes common suffixes from track titles for comparison
+func qobuzCleanTitle(title string) string {
+	cleaned := title
+
+	// Remove content in parentheses/brackets that are version indicators
+	// This helps match "Song (Remastered)" with "Song" or "Song (2024 Remaster)"
+	versionPatterns := []string{
+		"remaster", "remastered", "deluxe", "bonus", "single",
+		"album version", "radio edit", "original mix", "extended",
+		"club mix", "remix", "live", "acoustic", "demo",
+	}
+
+	// Remove parenthetical content if it contains version indicators
+	for {
+		startParen := strings.LastIndex(cleaned, "(")
+		endParen := strings.LastIndex(cleaned, ")")
+		if startParen >= 0 && endParen > startParen {
+			content := strings.ToLower(cleaned[startParen+1 : endParen])
+			isVersionIndicator := false
+			for _, pattern := range versionPatterns {
+				if strings.Contains(content, pattern) {
+					isVersionIndicator = true
+					break
+				}
+			}
+			if isVersionIndicator {
+				cleaned = strings.TrimSpace(cleaned[:startParen]) + cleaned[endParen+1:]
+				continue
+			}
+		}
+		break
+	}
+
+	// Same for brackets
+	for {
+		startBracket := strings.LastIndex(cleaned, "[")
+		endBracket := strings.LastIndex(cleaned, "]")
+		if startBracket >= 0 && endBracket > startBracket {
+			content := strings.ToLower(cleaned[startBracket+1 : endBracket])
+			isVersionIndicator := false
+			for _, pattern := range versionPatterns {
+				if strings.Contains(content, pattern) {
+					isVersionIndicator = true
+					break
+				}
+			}
+			if isVersionIndicator {
+				cleaned = strings.TrimSpace(cleaned[:startBracket]) + cleaned[endBracket+1:]
+				continue
+			}
+		}
+		break
+	}
+
+	// Remove trailing " - version" patterns
+	dashPatterns := []string{
+		" - remaster", " - remastered", " - single version", " - radio edit",
+		" - live", " - acoustic", " - demo", " - remix",
+	}
+	for _, pattern := range dashPatterns {
+		if strings.HasSuffix(strings.ToLower(cleaned), pattern) {
+			cleaned = cleaned[:len(cleaned)-len(pattern)]
+		}
+	}
+
+	// Remove multiple spaces
+	for strings.Contains(cleaned, "  ") {
+		cleaned = strings.ReplaceAll(cleaned, "  ", " ")
+	}
+
+	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.)
+		// Latin Extended-B: U+0180 to U+024F
+		// Latin Extended Additional: U+1E00 to U+1EFF
+		// 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) || // CJK Unified Ideographs
+			(r >= 0x3040 && r <= 0x309F) || // Hiragana
+			(r >= 0x30A0 && r <= 0x30FF) || // Katakana
+			(r >= 0xAC00 && r <= 0xD7AF) || // Hangul (Korean)
+			(r >= 0x0600 && r <= 0x06FF) || // Arabic
+			(r >= 0x0400 && r <= 0x04FF) { // Cyrillic
+			return false
+		}
+	}
+	return true
+}
+
+// qobuzIsASCIIString checks if a string contains only ASCII characters
+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 {
+			return true
+		}
+	}
+	return false
+}
+
+// NewQobuzDownloader creates a new Qobuz downloader (returns singleton for connection reuse)
+func NewQobuzDownloader() *QobuzDownloader {
+	qobuzDownloaderOnce.Do(func() {
+		globalQobuzDownloader = &QobuzDownloader{
+			client: NewHTTPClientWithTimeout(DefaultTimeout), // 60s timeout
+			appID:  "798273057",
+		}
+	})
+	return globalQobuzDownloader
 }
 
 // GetAvailableAPIs returns list of available Qobuz APIs
@@ -53,8 +307,8 @@ func (q *QobuzDownloader) GetAvailableAPIs() []string {
 	// Same APIs as PC version (referensi/backend/qobuz.go)
 	// Primary: dab.yeet.su, Fallback: dabmusic.xyz
 	encodedAPIs := []string{
-		"ZGFiLnllZXQuc3UvYXBpL3N0cmVhbT90cmFja0lkPQ==",     // dab.yeet.su/api/stream?trackId= (PRIMARY - same as PC)
-		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=",     // dabmusic.xyz/api/stream?trackId= (FALLBACK - same as PC)
+		"ZGFiLnllZXQuc3UvYXBpL3N0cmVhbT90cmFja0lkPQ==", // dab.yeet.su/api/stream?trackId= (PRIMARY - same as PC)
+		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=", // dabmusic.xyz/api/stream?trackId= (FALLBACK - same as PC)
 	}
 
 	var apis []string
@@ -112,11 +366,107 @@ func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
 }
 
+// SearchTrackByISRCWithTitle searches for a track by ISRC with duration verification
+// 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)
+
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
+	searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(isrc), q.appID)
+
+	req, err := http.NewRequest("GET", searchURL, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := DoRequestWithUserAgent(q.client, req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("search failed: HTTP %d", resp.StatusCode)
+	}
+
+	var result struct {
+		Tracks struct {
+			Items []QobuzTrack `json:"items"`
+		} `json:"tracks"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, err
+	}
+
+	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 {
+			isrcMatches = append(isrcMatches, &result.Tracks.Items[i])
+		}
+	}
+
+	GoLog("[Qobuz] Found %d exact ISRC matches\n", len(isrcMatches))
+
+	if len(isrcMatches) > 0 {
+		// Verify duration if provided
+		if expectedDurationSec > 0 {
+			var durationVerifiedMatches []*QobuzTrack
+			for _, track := range isrcMatches {
+				durationDiff := track.Duration - expectedDurationSec
+				if durationDiff < 0 {
+					durationDiff = -durationDiff
+				}
+				// Allow 10 seconds tolerance
+				if durationDiff <= 10 {
+					durationVerifiedMatches = append(durationVerifiedMatches, track)
+				}
+			}
+
+			if len(durationVerifiedMatches) > 0 {
+				GoLog("[Qobuz] ISRC match with duration verification: '%s' (expected %ds, found %ds)\n",
+					durationVerifiedMatches[0].Title, expectedDurationSec, durationVerifiedMatches[0].Duration)
+				return durationVerifiedMatches[0], nil
+			}
+
+			// ISRC matches but duration doesn't
+			GoLog("[Qobuz] WARNING: ISRC %s found but duration mismatch. Expected=%ds, Found=%ds. Rejecting.\n",
+				isrc, expectedDurationSec, isrcMatches[0].Duration)
+			return nil, fmt.Errorf("ISRC found but duration mismatch: expected %ds, found %ds (likely different version)",
+				expectedDurationSec, isrcMatches[0].Duration)
+		}
+
+		// No duration to verify, return first match
+		GoLog("[Qobuz] ISRC match (no duration verification): '%s'\n", isrcMatches[0].Title)
+		return isrcMatches[0], nil
+	}
+
+	if len(result.Tracks.Items) == 0 {
+		return nil, fmt.Errorf("no tracks found for ISRC: %s", isrc)
+	}
+
+	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
+}
+
+// SearchTrackByISRCWithTitle is deprecated, use SearchTrackByISRCWithDuration instead
+func (q *QobuzDownloader) SearchTrackByISRCWithTitle(isrc, expectedTitle string) (*QobuzTrack, error) {
+	return q.SearchTrackByISRCWithDuration(isrc, 0)
+}
+
 // SearchTrackByMetadata searches for a track using artist name and track name
 func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*QobuzTrack, error) {
+	return q.SearchTrackByMetadataWithDuration(trackName, artistName, 0)
+}
+
+// SearchTrackByMetadataWithDuration searches for a track with duration verification
+// 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
+	// Try multiple search strategies (same as Tidal/PC version)
 	queries := []string{}
 
 	// Strategy 1: Artist + Track name
@@ -129,8 +479,54 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 		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) {
+				queries = append(queries, romajiQuery)
+				GoLog("[Qobuz] Japanese detected, adding romaji query: %s\n", romajiQuery)
+			}
+		}
+
+		// Track romaji only (cleaned)
+		if cleanRomajiTrack != "" && cleanRomajiTrack != trackName {
+			if !containsQueryQobuz(queries, cleanRomajiTrack) {
+				queries = append(queries, cleanRomajiTrack)
+			}
+		}
+	}
+
+	// Strategy 4: Artist only as last resort
+	if artistName != "" {
+		artistOnly := CleanToASCII(JapaneseToRomaji(artistName))
+		if artistOnly != "" && !containsQueryQobuz(queries, artistOnly) {
+			queries = append(queries, artistOnly)
+		}
+	}
+
+	var allTracks []QobuzTrack
+	searchedQueries := make(map[string]bool)
+
 	for _, query := range queries {
-		searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(query), q.appID)
+		cleanQuery := strings.TrimSpace(query)
+		if cleanQuery == "" || searchedQueries[cleanQuery] {
+			continue
+		}
+		searchedQueries[cleanQuery] = true
+
+		GoLog("[Qobuz] Searching for: %s\n", cleanQuery)
+
+		searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(cleanQuery), q.appID)
 
 		req, err := http.NewRequest("GET", searchURL, nil)
 		if err != nil {
@@ -139,6 +535,7 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 
 		resp, err := DoRequestWithUserAgent(q.client, req)
 		if err != nil {
+			GoLog("[Qobuz] Search error for '%s': %v\n", cleanQuery, err)
 			continue
 		}
 
@@ -159,19 +556,82 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 		resp.Body.Close()
 
 		if len(result.Tracks.Items) > 0 {
-			// Return first result with best quality
-			for i := range result.Tracks.Items {
-				track := &result.Tracks.Items[i]
-				if track.MaximumBitDepth >= 24 {
-					return track, nil
-				}
-			}
-			// Return first result if no hi-res found
-			return &result.Tracks.Items[0], nil
+			GoLog("[Qobuz] Found %d results for '%s'\n", len(result.Tracks.Items), cleanQuery)
+			allTracks = append(allTracks, result.Tracks.Items...)
 		}
 	}
 
-	return nil, fmt.Errorf("no tracks found for: %s - %s", artistName, trackName)
+	if len(allTracks) == 0 {
+		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]
+		if qobuzTitlesMatch(trackName, track.Title) {
+			titleMatches = append(titleMatches, track)
+		}
+	}
+
+	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))
+		for i := range allTracks {
+			tracksToCheck = append(tracksToCheck, &allTracks[i])
+		}
+	}
+
+	// If duration verification is requested
+	if expectedDurationSec > 0 {
+		var durationMatches []*QobuzTrack
+		for _, track := range tracksToCheck {
+			durationDiff := track.Duration - expectedDurationSec
+			if durationDiff < 0 {
+				durationDiff = -durationDiff
+			}
+			if durationDiff <= 10 {
+				durationMatches = append(durationMatches, track)
+			}
+		}
+
+		if len(durationMatches) > 0 {
+			// Return best quality among duration matches
+			for _, track := range durationMatches {
+				if track.MaximumBitDepth >= 24 {
+					GoLog("[Qobuz] ✓ Match found: '%s' by '%s' (title+duration verified, hi-res)\n",
+						track.Title, track.Performer.Name)
+					return track, nil
+				}
+			}
+			GoLog("[Qobuz] ✓ Match found: '%s' by '%s' (title+duration verified)\n",
+				durationMatches[0].Title, durationMatches[0].Performer.Name)
+			return durationMatches[0], nil
+		}
+
+		// No duration match found
+		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",
+				track.Title, track.Performer.Name)
+			return track, nil
+		}
+	}
+
+	if len(tracksToCheck) > 0 {
+		GoLog("[Qobuz] ✓ Match found: '%s' by '%s' (title verified)\n",
+			tracksToCheck[0].Title, tracksToCheck[0].Performer.Name)
+		return tracksToCheck[0], nil
+	}
+
+	return nil, fmt.Errorf("no matching track found for: %s - %s", artistName, trackName)
 }
 
 // getQobuzDownloadURLSequential requests download URL from APIs sequentially
@@ -190,7 +650,7 @@ func getQobuzDownloadURLSequential(apis []string, trackID int64, quality string)
 		// The apiURL already includes the path, just append trackID and quality
 		reqURL := fmt.Sprintf("%s%d&quality=%s", apiURL, trackID, quality)
 
-		fmt.Printf("[Qobuz] Trying: %s\n", reqURL)
+		GoLog("[Qobuz] Trying: %s\n", reqURL)
 
 		req, err := http.NewRequest("GET", reqURL, nil)
 		if err != nil {
@@ -235,7 +695,7 @@ func getQobuzDownloadURLSequential(apis []string, trackID int64, quality string)
 		}
 
 		if result.URL != "" {
-			fmt.Printf("[Qobuz] Got download URL from: %s\n", apiURL)
+			GoLog("[Qobuz] Got download URL from: %s\n", apiURL)
 			return apiURL, result.URL, nil
 		}
 
@@ -261,11 +721,12 @@ func (q *QobuzDownloader) GetDownloadURL(trackID int64, quality string) (string,
 }
 
 // DownloadFile downloads a file from URL with User-Agent and progress tracking
-func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath string) error {
-	// Set current file being downloaded
-	SetCurrentFile(filepath.Base(outputPath))
-	SetDownloading(true)
-	defer SetDownloading(false)
+func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
+	// Initialize item progress (required for all downloads)
+	if itemID != "" {
+		StartItemProgress(itemID)
+		defer CompleteItemProgress(itemID)
+	}
 
 	req, err := http.NewRequest("GET", downloadURL, nil)
 	if err != nil {
@@ -282,51 +743,140 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath string) error {
 		return fmt.Errorf("download failed: HTTP %d", resp.StatusCode)
 	}
 
+	expectedSize := resp.ContentLength
 	// Set total bytes if available
-	if resp.ContentLength > 0 {
-		SetBytesTotal(resp.ContentLength)
+	if expectedSize > 0 && itemID != "" {
+		SetItemBytesTotal(itemID, expectedSize)
 	}
 
 	out, err := os.Create(outputPath)
 	if err != nil {
 		return err
 	}
-	defer out.Close()
 
-	// Use ProgressWriter for tracking
-	progressWriter := NewProgressWriter(out)
-	_, err = io.Copy(progressWriter, resp.Body)
-	return err
+	// Use buffered writer for better performance (256KB buffer)
+	bufWriter := bufio.NewWriterSize(out, 256*1024)
+
+	// Use item progress writer with buffered output
+	var written int64
+	if itemID != "" {
+		progressWriter := NewItemProgressWriter(bufWriter, itemID)
+		written, err = io.Copy(progressWriter, resp.Body)
+	} else {
+		// Fallback: direct copy without progress tracking
+		written, err = io.Copy(bufWriter, resp.Body)
+	}
+
+	// Flush buffer before checking for errors
+	flushErr := bufWriter.Flush()
+	closeErr := out.Close()
+
+	// Check for any errors
+	if err != nil {
+		os.Remove(outputPath)
+		return fmt.Errorf("download interrupted: %w", err)
+	}
+	if flushErr != nil {
+		os.Remove(outputPath)
+		return fmt.Errorf("failed to flush buffer: %w", flushErr)
+	}
+	if closeErr != nil {
+		os.Remove(outputPath)
+		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)
+	}
+
+	return nil
+}
+
+// QobuzDownloadResult contains download result with quality info
+type QobuzDownloadResult struct {
+	FilePath    string
+	BitDepth    int
+	SampleRate  int
+	Title       string
+	Artist      string
+	Album       string
+	ReleaseDate string
+	TrackNumber int
+	DiscNumber  int
+	ISRC        string
 }
 
 // downloadFromQobuz downloads a track using the request parameters
-func downloadFromQobuz(req DownloadRequest) (string, error) {
+func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 	downloader := NewQobuzDownloader()
 
 	// Check for existing file first
 	if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
-		return "EXISTS:" + existingFile, nil
+		return QobuzDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
+	// Convert expected duration from ms to seconds
+	expectedDurationSec := req.DurationMS / 1000
+
 	var track *QobuzTrack
 	var err error
 
-	// Strategy 1: Search by ISRC
+	// OPTIMIZATION: Check cache first for track ID
 	if req.ISRC != "" {
-		track, err = downloader.SearchTrackByISRC(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)
+				track = nil
+			}
+		}
 	}
 
-	// Strategy 2: Search by metadata
+	// 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",
+					req.ArtistName, track.Performer.Name)
+				track = nil
+			} else if !qobuzTitlesMatch(req.TrackName, track.Title) {
+				GoLog("[Qobuz] Title mismatch from ISRC search: expected '%s', got '%s'. Rejecting.\n",
+					req.TrackName, track.Title)
+				track = nil
+			}
+		}
+	}
+
+	// Strategy 2: Search by metadata with duration verification (includes title verification)
 	if track == nil {
-		track, err = downloader.SearchTrackByMetadata(req.TrackName, req.ArtistName)
+		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)
+			track = nil
+		}
 	}
 
 	if track == nil {
-		errMsg := "could not find track on Qobuz"
+		errMsg := "could not find matching track on Qobuz (artist/duration mismatch)"
 		if err != nil {
 			errMsg = err.Error()
 		}
-		return "", fmt.Errorf("qobuz search failed: %s", errMsg)
+		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)
 	}
 
 	// Build filename
@@ -343,69 +893,120 @@ func downloadFromQobuz(req DownloadRequest) (string, error) {
 
 	// Check if file already exists
 	if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
-		return "EXISTS:" + outputPath, nil
+		return QobuzDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
 
+	// Map quality from Tidal format to Qobuz format
+	// 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
+	case "HI_RES":
+		qobuzQuality = "7" // 24-bit 96kHz
+	case "HI_RES_LOSSLESS":
+		qobuzQuality = "27" // 24-bit 192kHz
+	}
+	GoLog("[Qobuz] Using quality: %s (mapped from %s)\n", qobuzQuality, req.Quality)
+
+	// Get actual quality from track metadata
+	actualBitDepth := track.MaximumBitDepth
+	actualSampleRate := int(track.MaximumSamplingRate * 1000) // Convert kHz to Hz
+	GoLog("[Qobuz] Actual quality: %d-bit/%.1fkHz\n", actualBitDepth, track.MaximumSamplingRate)
+
 	// Get download URL using parallel API requests
-	downloadURL, err := downloader.GetDownloadURL(track.ID, "27") // 27 = FLAC 24-bit
+	downloadURL, err := downloader.GetDownloadURL(track.ID, qobuzQuality)
 	if err != nil {
-		return "", fmt.Errorf("failed to get download URL: %w", err)
+		return QobuzDownloadResult{}, fmt.Errorf("failed to get download URL: %w", err)
 	}
 
-	// Download file
-	if err := downloader.DownloadFile(downloadURL, outputPath); err != nil {
-		return "", fmt.Errorf("download failed: %w", err)
+	// START PARALLEL: Fetch cover and lyrics while downloading audio
+	var parallelResult *ParallelDownloadResult
+	parallelDone := make(chan struct{})
+	go func() {
+		defer close(parallelDone)
+		parallelResult = FetchCoverAndLyricsParallel(
+			req.CoverURL,
+			req.EmbedMaxQualityCover,
+			req.SpotifyID,
+			req.TrackName,
+			req.ArtistName,
+			req.EmbedLyrics,
+		)
+	}()
+
+	// Download audio file with item ID for progress tracking
+	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+		return QobuzDownloadResult{}, fmt.Errorf("download failed: %w", err)
+	}
+
+	// Wait for parallel operations to complete
+	<-parallelDone
+
+	// Set progress to 100% and status to finalizing (before embedding)
+	// This makes the UI show "Finalizing..." while embedding happens
+	if req.ItemID != "" {
+		SetItemProgress(req.ItemID, 1.0, 0, 0)
+		SetItemFinalizing(req.ItemID)
+	}
+
+	// Embed metadata using parallel-fetched cover data
+	// Use metadata from the actual Qobuz track found (more accurate than request) but prefer
+	// requested Album Name to avoid ISRC version mismatches (e.g. Compilations vs Original)
+	albumName := track.Album.Title
+	if req.AlbumName != "" {
+		albumName = req.AlbumName
 	}
 
-	// Embed metadata
 	metadata := Metadata{
-		Title:       req.TrackName,
-		Artist:      req.ArtistName,
-		Album:       req.AlbumName,
-		AlbumArtist: req.AlbumArtist,
-		Date:        req.ReleaseDate,
-		TrackNumber: req.TrackNumber,
+		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
+		Date:        track.Album.ReleaseDate,
+		TrackNumber: track.TrackNumber,
 		TotalTracks: req.TotalTracks,
-		DiscNumber:  req.DiscNumber,
-		ISRC:        req.ISRC,
+		DiscNumber:  req.DiscNumber, // QobuzTrack struct usually doesn't have disc info in simple search result
+		ISRC:        track.ISRC,
 	}
 
-	// Download cover to memory (avoids file permission issues on Android)
+	// Use cover data from parallel fetch
 	var coverData []byte
-	if req.CoverURL != "" {
-		fmt.Println("[Qobuz] Downloading cover to memory...")
-		data, err := downloadCoverToMemory(req.CoverURL, req.EmbedMaxQualityCover)
-		if err == nil {
-			coverData = data
-			fmt.Printf("[Qobuz] Cover downloaded successfully (%d bytes)\n", len(coverData))
-		} else {
-			fmt.Printf("[Qobuz] Warning: failed to download cover: %v\n", err)
-		}
+	if parallelResult != nil && parallelResult.CoverData != nil {
+		coverData = parallelResult.CoverData
+		GoLog("[Qobuz] Using parallel-fetched cover (%d bytes)\n", len(coverData))
 	}
 
 	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
 		fmt.Printf("Warning: failed to embed metadata: %v\n", err)
 	}
 
-	// Embed lyrics if enabled
-	if req.EmbedLyrics {
-		fmt.Println("[Qobuz] Fetching lyrics...")
-		lyricsClient := NewLyricsClient()
-		lyrics, lyricsErr := lyricsClient.FetchLyricsAllSources(req.SpotifyID, req.TrackName, req.ArtistName)
-		if lyricsErr != nil {
-			fmt.Printf("[Qobuz] Warning: lyrics fetch error: %v\n", lyricsErr)
-		} else if lyrics == nil || len(lyrics.Lines) == 0 {
-			fmt.Println("[Qobuz] No lyrics found for this track")
+	// Embed lyrics from parallel fetch
+	if req.EmbedLyrics && parallelResult != nil && parallelResult.LyricsLRC != "" {
+		GoLog("[Qobuz] Embedding parallel-fetched lyrics (%d lines)...\n", len(parallelResult.LyricsData.Lines))
+		if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+			GoLog("[Qobuz] Warning: failed to embed lyrics: %v\n", embedErr)
 		} else {
-			fmt.Printf("[Qobuz] Lyrics found (%d lines), embedding...\n", len(lyrics.Lines))
-			lrcContent := convertToLRC(lyrics)
-			if embedErr := EmbedLyrics(outputPath, lrcContent); embedErr != nil {
-				fmt.Printf("[Qobuz] Warning: failed to embed lyrics: %v\n", embedErr)
-			} else {
-				fmt.Println("[Qobuz] Lyrics embedded successfully")
-			}
+			fmt.Println("[Qobuz] Lyrics embedded successfully")
 		}
+	} else if req.EmbedLyrics {
+		fmt.Println("[Qobuz] No lyrics available from parallel fetch")
 	}
 
-	return outputPath, nil
+	// Add to ISRC index for fast duplicate checking
+	AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
+
+	return QobuzDownloadResult{
+		FilePath:    outputPath,
+		BitDepth:    actualBitDepth,
+		SampleRate:  actualSampleRate,
+		Title:       track.Title,
+		Artist:      track.Performer.Name,
+		Album:       track.Album.Title,
+		ReleaseDate: track.Album.ReleaseDate,
+		TrackNumber: track.TrackNumber,
+		DiscNumber:  req.DiscNumber, // Qobuz track struct limitations
+		ISRC:        track.ISRC,
+	}, nil
 }

go_backend/romaji.go

@@ -5,109 +5,61 @@ import (
 	"unicode"
 )
 
-// Japanese character ranges
-const (
-	hiraganaStart = 0x3040
-	hiraganaEnd   = 0x309F
-	katakanaStart = 0x30A0
-	katakanaEnd   = 0x30FF
-	kanjiStart    = 0x4E00
-	kanjiEnd      = 0x9FFF
-)
-
-// hiraganaToRomaji maps hiragana characters to romaji
+// Hiragana to Romaji mapping
 var hiraganaToRomaji = map[rune]string{
-	// Basic vowels
 	'あ': "a", 'い': "i", 'う': "u", 'え': "e", 'お': "o",
-	// K-row
 	'か': "ka", 'き': "ki", 'く': "ku", 'け': "ke", 'こ': "ko",
-	// S-row
 	'さ': "sa", 'し': "shi", 'す': "su", 'せ': "se", 'そ': "so",
-	// T-row
 	'た': "ta", 'ち': "chi", 'つ': "tsu", 'て': "te", 'と': "to",
-	// N-row
 	'な': "na", 'に': "ni", 'ぬ': "nu", 'ね': "ne", 'の': "no",
-	// H-row
 	'は': "ha", 'ひ': "hi", 'ふ': "fu", 'へ': "he", 'ほ': "ho",
-	// M-row
 	'ま': "ma", 'み': "mi", 'む': "mu", 'め': "me", 'も': "mo",
-	// Y-row
 	'や': "ya", 'ゆ': "yu", 'よ': "yo",
-	// R-row
 	'ら': "ra", 'り': "ri", 'る': "ru", 'れ': "re", 'ろ': "ro",
-	// W-row
-	'わ': "wa", 'を': "wo",
-	// N
-	'ん': "n",
-	// Voiced (dakuten) - G-row
+	'わ': "wa", 'を': "wo", 'ん': "n",
+	// Dakuten (voiced)
 	'が': "ga", 'ぎ': "gi", 'ぐ': "gu", 'げ': "ge", 'ご': "go",
-	// Z-row
 	'ざ': "za", 'じ': "ji", 'ず': "zu", 'ぜ': "ze", 'ぞ': "zo",
-	// D-row
 	'だ': "da", 'ぢ': "ji", 'づ': "zu", 'で': "de", 'ど': "do",
-	// B-row
 	'ば': "ba", 'び': "bi", 'ぶ': "bu", 'べ': "be", 'ぼ': "bo",
-	// P-row (handakuten)
+	// Handakuten (semi-voiced)
 	'ぱ': "pa", 'ぴ': "pi", 'ぷ': "pu", 'ぺ': "pe", 'ぽ': "po",
 	// Small characters
 	'ゃ': "ya", 'ゅ': "yu", 'ょ': "yo",
+	'っ': "", // Double consonant marker
 	'ぁ': "a", 'ぃ': "i", 'ぅ': "u", 'ぇ': "e", 'ぉ': "o",
-	'っ': "", // Small tsu - handled specially
-	// Long vowel mark
-	'ー': "",
 }
 
-// katakanaToRomaji maps katakana characters to romaji
+// Katakana to Romaji mapping
 var katakanaToRomaji = map[rune]string{
-	// Basic vowels
 	'ア': "a", 'イ': "i", 'ウ': "u", 'エ': "e", 'オ': "o",
-	// K-row
 	'カ': "ka", 'キ': "ki", 'ク': "ku", 'ケ': "ke", 'コ': "ko",
-	// S-row
 	'サ': "sa", 'シ': "shi", 'ス': "su", 'セ': "se", 'ソ': "so",
-	// T-row
 	'タ': "ta", 'チ': "chi", 'ツ': "tsu", 'テ': "te", 'ト': "to",
-	// N-row
 	'ナ': "na", 'ニ': "ni", 'ヌ': "nu", 'ネ': "ne", 'ノ': "no",
-	// H-row
 	'ハ': "ha", 'ヒ': "hi", 'フ': "fu", 'ヘ': "he", 'ホ': "ho",
-	// M-row
 	'マ': "ma", 'ミ': "mi", 'ム': "mu", 'メ': "me", 'モ': "mo",
-	// Y-row
 	'ヤ': "ya", 'ユ': "yu", 'ヨ': "yo",
-	// R-row
 	'ラ': "ra", 'リ': "ri", 'ル': "ru", 'レ': "re", 'ロ': "ro",
-	// W-row
-	'ワ': "wa", 'ヲ': "wo",
-	// N
-	'ン': "n",
-	// Voiced (dakuten) - G-row
+	'ワ': "wa", 'ヲ': "wo", 'ン': "n",
+	// Dakuten (voiced)
 	'ガ': "ga", 'ギ': "gi", 'グ': "gu", 'ゲ': "ge", 'ゴ': "go",
-	// Z-row
 	'ザ': "za", 'ジ': "ji", 'ズ': "zu", 'ゼ': "ze", 'ゾ': "zo",
-	// D-row
 	'ダ': "da", 'ヂ': "ji", 'ヅ': "zu", 'デ': "de", 'ド': "do",
-	// B-row
 	'バ': "ba", 'ビ': "bi", 'ブ': "bu", 'ベ': "be", 'ボ': "bo",
-	// P-row (handakuten)
+	// Handakuten (semi-voiced)
 	'パ': "pa", 'ピ': "pi", 'プ': "pu", 'ペ': "pe", 'ポ': "po",
 	// Small characters
 	'ャ': "ya", 'ュ': "yu", 'ョ': "yo",
+	'ッ': "", // Double consonant marker
 	'ァ': "a", 'ィ': "i", 'ゥ': "u", 'ェ': "e", 'ォ': "o",
-	'ッ': "", // Small tsu - handled specially
 	// Extended katakana
+	'ー': "", // Long vowel mark
 	'ヴ': "vu",
-	// Long vowel mark
-	'ー': "",
 }
 
-// Extended katakana combinations (multi-character)
-var katakanaExtended = map[string]string{
-	"ファ": "fa", "フィ": "fi", "フェ": "fe", "フォ": "fo",
-}
-
-// Combination mappings for small ya/yu/yo
-var hiraganaCombo = map[string]string{
+// Combination mappings for きゃ, しゃ, etc.
+var combinationHiragana = map[string]string{
 	"きゃ": "kya", "きゅ": "kyu", "きょ": "kyo",
 	"しゃ": "sha", "しゅ": "shu", "しょ": "sho",
 	"ちゃ": "cha", "ちゅ": "chu", "ちょ": "cho",
@@ -121,7 +73,7 @@ var hiraganaCombo = map[string]string{
 	"ぴゃ": "pya", "ぴゅ": "pyu", "ぴょ": "pyo",
 }
 
-var katakanaCombo = map[string]string{
+var combinationKatakana = map[string]string{
 	"キャ": "kya", "キュ": "kyu", "キョ": "kyo",
 	"シャ": "sha", "シュ": "shu", "ショ": "sho",
 	"チャ": "cha", "チュ": "chu", "チョ": "cho",
@@ -133,15 +85,13 @@ var katakanaCombo = map[string]string{
 	"ジャ": "ja", "ジュ": "ju", "ジョ": "jo",
 	"ビャ": "bya", "ビュ": "byu", "ビョ": "byo",
 	"ピャ": "pya", "ピュ": "pyu", "ピョ": "pyo",
-	// Extended katakana combinations
-	"ティ": "ti", "ディ": "di",
-	"トゥ": "tu", "ドゥ": "du",
+	// Extended combinations
+	"ティ": "ti", "ディ": "di", "トゥ": "tu", "ドゥ": "du",
 	"ファ": "fa", "フィ": "fi", "フェ": "fe", "フォ": "fo",
 	"ウィ": "wi", "ウェ": "we", "ウォ": "wo",
-	"ヴァ": "va", "ヴィ": "vi", "ヴェ": "ve", "ヴォ": "vo",
 }
 
-// ContainsJapanese checks if a string contains Japanese characters (Hiragana, Katakana, or Kanji)
+// ContainsJapanese checks if a string contains Japanese characters
 func ContainsJapanese(s string) bool {
 	for _, r := range s {
 		if isHiragana(r) || isKatakana(r) || isKanji(r) {
@@ -151,107 +101,72 @@ func ContainsJapanese(s string) bool {
 	return false
 }
 
-// ContainsKana checks if a string contains Hiragana or Katakana (convertible to romaji)
-func ContainsKana(s string) bool {
-	for _, r := range s {
-		if isHiragana(r) || isKatakana(r) {
-			return true
-		}
-	}
-	return false
-}
-
 func isHiragana(r rune) bool {
-	return r >= hiraganaStart && r <= hiraganaEnd
+	return r >= 0x3040 && r <= 0x309F
 }
 
 func isKatakana(r rune) bool {
-	return r >= katakanaStart && r <= katakanaEnd
+	return r >= 0x30A0 && r <= 0x30FF
 }
 
 func isKanji(r rune) bool {
-	return r >= kanjiStart && r <= kanjiEnd
+	return (r >= 0x4E00 && r <= 0x9FFF) || // CJK Unified Ideographs
+		(r >= 0x3400 && r <= 0x4DBF) // CJK Unified Ideographs Extension A
 }
 
-// ToRomaji converts Japanese kana (Hiragana/Katakana) to romaji
-// Kanji characters are preserved as-is since they require dictionary lookup
-func ToRomaji(s string) string {
-	if !ContainsKana(s) {
-		return s
+// JapaneseToRomaji converts Japanese text (hiragana/katakana) to romaji
+// Note: Kanji cannot be converted without a dictionary, so they are kept as-is
+func JapaneseToRomaji(text string) string {
+	if !ContainsJapanese(text) {
+		return text
 	}
 
-	runes := []rune(s)
 	var result strings.Builder
-	result.Grow(len(s) * 2) // Romaji is typically longer
-
+	runes := []rune(text)
 	i := 0
+
 	for i < len(runes) {
-		r := runes[i]
+		// Check for っ/ッ (double consonant)
+		if i < len(runes)-1 && (runes[i] == 'っ' || runes[i] == 'ッ') {
+			nextRomaji := ""
+			if romaji, ok := hiraganaToRomaji[runes[i+1]]; ok {
+				nextRomaji = romaji
+			} else if romaji, ok := katakanaToRomaji[runes[i+1]]; ok {
+				nextRomaji = romaji
+			}
+			if len(nextRomaji) > 0 {
+				result.WriteByte(nextRomaji[0]) // Double the first consonant
+			}
+			i++
+			continue
+		}
 
-		// Check for two-character combinations first
-		if i+1 < len(runes) {
+		// Check for two-character combinations
+		if i < len(runes)-1 {
 			combo := string(runes[i : i+2])
-			if romaji, ok := hiraganaCombo[combo]; ok {
+			if romaji, ok := combinationHiragana[combo]; ok {
 				result.WriteString(romaji)
 				i += 2
 				continue
 			}
-			if romaji, ok := katakanaCombo[combo]; ok {
+			if romaji, ok := combinationKatakana[combo]; ok {
 				result.WriteString(romaji)
 				i += 2
 				continue
 			}
 		}
 
-		// Handle small tsu (っ/ッ) - doubles the next consonant
-		if r == 'っ' || r == 'ッ' {
-			if i+1 < len(runes) {
-				nextRune := runes[i+1]
-				var nextRomaji string
-				if romaji, ok := hiraganaToRomaji[nextRune]; ok {
-					nextRomaji = romaji
-				} else if romaji, ok := katakanaToRomaji[nextRune]; ok {
-					nextRomaji = romaji
-				}
-				if len(nextRomaji) > 0 {
-					result.WriteByte(nextRomaji[0]) // Double the consonant
-				}
-			}
-			i++
-			continue
-		}
-
-		// Handle long vowel mark (ー)
-		if r == 'ー' {
-			// Extend the previous vowel
-			resultStr := result.String()
-			if len(resultStr) > 0 {
-				lastChar := resultStr[len(resultStr)-1]
-				if lastChar == 'a' || lastChar == 'i' || lastChar == 'u' || lastChar == 'e' || lastChar == 'o' {
-					result.WriteByte(lastChar)
-				}
-			}
-			i++
-			continue
-		}
-
 		// Single character conversion
+		r := runes[i]
 		if romaji, ok := hiraganaToRomaji[r]; ok {
 			result.WriteString(romaji)
-			i++
-			continue
-		}
-
-		if romaji, ok := katakanaToRomaji[r]; ok {
+		} else if romaji, ok := katakanaToRomaji[r]; ok {
 			result.WriteString(romaji)
-			i++
-			continue
-		}
-
-		// Keep non-Japanese characters as-is
-		if unicode.IsSpace(r) {
-			result.WriteRune(' ')
+		} else if isKanji(r) {
+			// Keep kanji as-is (would need dictionary for proper conversion)
+			result.WriteRune(r)
 		} else {
+			// Keep other characters (punctuation, spaces, etc.)
 			result.WriteRune(r)
 		}
 		i++
@@ -260,17 +175,48 @@ func ToRomaji(s string) string {
 	return result.String()
 }
 
-// GetRomajiVariants returns search variants for Japanese text
-// Returns the original string plus romaji version if applicable
-func GetRomajiVariants(s string) []string {
-	variants := []string{s}
+// BuildSearchQuery creates a search query from track name and artist
+// Converts Japanese to romaji if present
+func BuildSearchQuery(trackName, artistName string) string {
+	// Convert Japanese to romaji
+	trackRomaji := JapaneseToRomaji(trackName)
+	artistRomaji := JapaneseToRomaji(artistName)
 
-	if ContainsKana(s) {
-		romaji := ToRomaji(s)
-		if romaji != s && strings.TrimSpace(romaji) != "" {
-			variants = append(variants, romaji)
+	// Clean up the query - remove special characters that might interfere with search
+	trackClean := cleanSearchQuery(trackRomaji)
+	artistClean := cleanSearchQuery(artistRomaji)
+
+	return strings.TrimSpace(artistClean + " " + trackClean)
+}
+
+// cleanSearchQuery removes special characters that might interfere with search
+func cleanSearchQuery(s string) string {
+	var result strings.Builder
+	for _, r := range s {
+		if unicode.IsLetter(r) || unicode.IsNumber(r) || unicode.IsSpace(r) {
+			result.WriteRune(r)
+		} else if r == '-' || r == '\'' {
+			result.WriteRune(r)
 		}
 	}
-
-	return variants
+	return strings.TrimSpace(result.String())
+}
+
+// CleanToASCII removes all non-ASCII characters and keeps only letters, numbers, spaces
+// This is useful for creating search queries that work better with Tidal's search
+func CleanToASCII(s string) string {
+	var result strings.Builder
+	for _, r := range s {
+		// Keep only ASCII letters, numbers, spaces, and basic punctuation
+		if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') ||
+			(r >= '0' && r <= '9') || r == ' ' || r == '-' || r == '\'' {
+			result.WriteRune(r)
+		} else if r == ',' || r == '.' {
+			// Convert punctuation to space
+			result.WriteRune(' ')
+		}
+	}
+	// Clean up multiple spaces
+	cleaned := strings.Join(strings.Fields(result.String()), " ")
+	return strings.TrimSpace(cleaned)
 }

go_backend/songlink.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"strings"
+	"sync"
 	"time"
 )
 
@@ -20,20 +22,37 @@ type TrackAvailability struct {
 	Tidal     bool   `json:"tidal"`
 	Amazon    bool   `json:"amazon"`
 	Qobuz     bool   `json:"qobuz"`
+	Deezer    bool   `json:"deezer"`
 	TidalURL  string `json:"tidal_url,omitempty"`
 	AmazonURL string `json:"amazon_url,omitempty"`
 	QobuzURL  string `json:"qobuz_url,omitempty"`
+	DeezerURL string `json:"deezer_url,omitempty"`
+	DeezerID  string `json:"deezer_id,omitempty"`
 }
 
-// NewSongLinkClient creates a new SongLink client
+var (
+	// Global SongLink client instance for connection reuse
+	globalSongLinkClient *SongLinkClient
+	songLinkClientOnce   sync.Once
+)
+
+// NewSongLinkClient creates a new SongLink client (returns singleton for connection reuse)
 func NewSongLinkClient() *SongLinkClient {
-	return &SongLinkClient{
-		client: NewHTTPClientWithTimeout(SongLinkTimeout), // 30s timeout
-	}
+	songLinkClientOnce.Do(func() {
+		globalSongLinkClient = &SongLinkClient{
+			client: NewHTTPClientWithTimeout(SongLinkTimeout), // 30s timeout
+		}
+	})
+	return globalSongLinkClient
 }
 
 // CheckTrackAvailability checks track availability on streaming platforms
 func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc string) (*TrackAvailability, error) {
+	// Validate Spotify ID format (should be 22 characters alphanumeric)
+	if spotifyTrackID == "" {
+		return nil, fmt.Errorf("spotify track ID is empty")
+	}
+	
 	// Use global rate limiter - blocks until request is allowed
 	songLinkRateLimiter.WaitForSlot()
 
@@ -57,8 +76,18 @@ func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc stri
 	}
 	defer resp.Body.Close()
 
+	// Handle specific error codes
+	if resp.StatusCode == 400 {
+		return nil, fmt.Errorf("track not found on SongLink (invalid Spotify ID or track unavailable)")
+	}
+	if resp.StatusCode == 404 {
+		return nil, fmt.Errorf("track not found on any streaming platform")
+	}
+	if resp.StatusCode == 429 {
+		return nil, fmt.Errorf("SongLink rate limit exceeded")
+	}
 	if resp.StatusCode != 200 {
-		return nil, fmt.Errorf("API returned status %d", resp.StatusCode)
+		return nil, fmt.Errorf("SongLink API returned status %d", resp.StatusCode)
 	}
 
 	body, err := ReadResponseBody(resp)
@@ -92,7 +121,15 @@ func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc stri
 		availability.AmazonURL = amazonLink.URL
 	}
 
-	// Check Qobuz using ISRC
+	// Check Deezer
+	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
+		availability.Deezer = true
+		availability.DeezerURL = deezerLink.URL
+		// Extract Deezer ID from URL (e.g., https://www.deezer.com/track/123456)
+		availability.DeezerID = extractDeezerIDFromURL(deezerLink.URL)
+	}
+
+	// Check Qobuz using ISRC (SongLink doesn't support Qobuz directly)
 	if isrc != "" {
 		availability.Qobuz = checkQobuzAvailability(isrc)
 	}
@@ -151,3 +188,357 @@ func checkQobuzAvailability(isrc string) bool {
 
 	return searchResp.Tracks.Total > 0
 }
+
+// extractDeezerIDFromURL extracts Deezer track/album/artist ID from URL
+func extractDeezerIDFromURL(deezerURL string) string {
+	// URL format: https://www.deezer.com/track/123456 or https://www.deezer.com/en/track/123456
+	parts := strings.Split(deezerURL, "/")
+	if len(parts) > 0 {
+		// Get the last part which should be the ID
+		lastPart := parts[len(parts)-1]
+		// Remove any query parameters
+		if idx := strings.Index(lastPart, "?"); idx > 0 {
+			lastPart = lastPart[:idx]
+		}
+		return lastPart
+	}
+	return ""
+}
+
+// GetDeezerIDFromSpotify converts a Spotify track ID to Deezer track ID using SongLink
+func (s *SongLinkClient) GetDeezerIDFromSpotify(spotifyTrackID string) (string, error) {
+	availability, err := s.CheckTrackAvailability(spotifyTrackID, "")
+	if err != nil {
+		return "", err
+	}
+	
+	if !availability.Deezer || availability.DeezerID == "" {
+		return "", fmt.Errorf("track not found on Deezer")
+	}
+	
+	return availability.DeezerID, nil
+}
+
+// AlbumAvailability represents album availability on different platforms
+type AlbumAvailability struct {
+	SpotifyID string `json:"spotify_id"`
+	Deezer    bool   `json:"deezer"`
+	DeezerURL string `json:"deezer_url,omitempty"`
+	DeezerID  string `json:"deezer_id,omitempty"`
+}
+
+// CheckAlbumAvailability checks album availability on streaming platforms using SongLink
+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)
+
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9hcGkuc29uZy5saW5rL3YxLWFscGhhLjEvbGlua3M/dXJsPQ==")
+	apiURL := fmt.Sprintf("%s%s", string(apiBase), url.QueryEscape(spotifyURL))
+
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	retryConfig := DefaultRetryConfig()
+	resp, err := DoRequestWithRetry(s.client, req, retryConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check album availability: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("API returned status %d", resp.StatusCode)
+	}
+
+	body, err := ReadResponseBody(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var songLinkResp struct {
+		LinksByPlatform map[string]struct {
+			URL string `json:"url"`
+		} `json:"linksByPlatform"`
+	}
+
+	if err := json.Unmarshal(body, &songLinkResp); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	availability := &AlbumAvailability{
+		SpotifyID: spotifyAlbumID,
+	}
+
+	// Check Deezer
+	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
+		availability.Deezer = true
+		availability.DeezerURL = deezerLink.URL
+		availability.DeezerID = extractDeezerIDFromURL(deezerLink.URL)
+	}
+
+	return availability, nil
+}
+
+// GetDeezerAlbumIDFromSpotify converts a Spotify album ID to Deezer album ID using SongLink
+func (s *SongLinkClient) GetDeezerAlbumIDFromSpotify(spotifyAlbumID string) (string, error) {
+	availability, err := s.CheckAlbumAvailability(spotifyAlbumID)
+	if err != nil {
+		return "", err
+	}
+	
+	if !availability.Deezer || availability.DeezerID == "" {
+		return "", fmt.Errorf("album not found on Deezer")
+	}
+	
+	return availability.DeezerID, nil
+}
+
+// ========================================
+// Deezer ID Support - Query SongLink using Deezer as source
+// ========================================
+
+// CheckAvailabilityFromDeezer checks track availability using Deezer track ID as source
+// This is useful when we have Deezer metadata and want to find the track on other platforms
+func (s *SongLinkClient) CheckAvailabilityFromDeezer(deezerTrackID string) (*TrackAvailability, error) {
+	if deezerTrackID == "" {
+		return nil, fmt.Errorf("deezer track ID is empty")
+	}
+	
+	// Use global rate limiter
+	songLinkRateLimiter.WaitForSlot()
+
+	// Build Deezer URL
+	deezerURL := fmt.Sprintf("https://www.deezer.com/track/%s", deezerTrackID)
+
+	// Build API URL using Deezer URL as source
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9hcGkuc29uZy5saW5rL3YxLWFscGhhLjEvbGlua3M/dXJsPQ==")
+	apiURL := fmt.Sprintf("%s%s&userCountry=US", string(apiBase), url.QueryEscape(deezerURL))
+
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	retryConfig := DefaultRetryConfig()
+	resp, err := DoRequestWithRetry(s.client, req, retryConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check availability: %w", err)
+	}
+	defer resp.Body.Close()
+
+	// Handle specific error codes
+	if resp.StatusCode == 400 {
+		return nil, fmt.Errorf("track not found on SongLink (invalid Deezer ID)")
+	}
+	if resp.StatusCode == 404 {
+		return nil, fmt.Errorf("track not found on any streaming platform")
+	}
+	if resp.StatusCode == 429 {
+		return nil, fmt.Errorf("SongLink rate limit exceeded")
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("SongLink API returned status %d", resp.StatusCode)
+	}
+
+	body, err := ReadResponseBody(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var songLinkResp struct {
+		LinksByPlatform map[string]struct {
+			URL string `json:"url"`
+		} `json:"linksByPlatform"`
+		EntitiesByUniqueId map[string]struct {
+			ID         string `json:"id"`
+			Type       string `json:"type"`
+			Title      string `json:"title"`
+			ArtistName string `json:"artistName"`
+		} `json:"entitiesByUniqueId"`
+	}
+
+	if err := json.Unmarshal(body, &songLinkResp); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	availability := &TrackAvailability{
+		Deezer:   true,
+		DeezerID: deezerTrackID,
+	}
+
+	// Check Spotify
+	if spotifyLink, ok := songLinkResp.LinksByPlatform["spotify"]; ok && spotifyLink.URL != "" {
+		// Extract Spotify ID from URL
+		availability.SpotifyID = extractSpotifyIDFromURL(spotifyLink.URL)
+	}
+
+	// Check Tidal
+	if tidalLink, ok := songLinkResp.LinksByPlatform["tidal"]; ok && tidalLink.URL != "" {
+		availability.Tidal = true
+		availability.TidalURL = tidalLink.URL
+	}
+
+	// Check Amazon
+	if amazonLink, ok := songLinkResp.LinksByPlatform["amazonMusic"]; ok && amazonLink.URL != "" {
+		availability.Amazon = true
+		availability.AmazonURL = amazonLink.URL
+	}
+
+	// Check Deezer URL
+	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
+		availability.DeezerURL = deezerLink.URL
+	}
+
+	return availability, nil
+}
+
+// CheckAvailabilityByPlatform checks track availability using any supported platform
+// platform: "spotify", "deezer", "tidal", "amazonMusic", "appleMusic", "youtube", etc.
+// entityType: "song" or "album"
+// entityID: the ID on that platform
+func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entityID string) (*TrackAvailability, error) {
+	if entityID == "" {
+		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),
+		url.QueryEscape(entityID))
+
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	retryConfig := DefaultRetryConfig()
+	resp, err := DoRequestWithRetry(s.client, req, retryConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check availability: %w", err)
+	}
+	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)
+	}
+	if resp.StatusCode == 404 {
+		return nil, fmt.Errorf("track not found on any streaming platform")
+	}
+	if resp.StatusCode == 429 {
+		return nil, fmt.Errorf("SongLink rate limit exceeded")
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("SongLink API returned status %d", resp.StatusCode)
+	}
+
+	body, err := ReadResponseBody(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var songLinkResp struct {
+		LinksByPlatform map[string]struct {
+			URL string `json:"url"`
+		} `json:"linksByPlatform"`
+	}
+
+	if err := json.Unmarshal(body, &songLinkResp); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	availability := &TrackAvailability{}
+
+	// Check Spotify
+	if spotifyLink, ok := songLinkResp.LinksByPlatform["spotify"]; ok && spotifyLink.URL != "" {
+		availability.SpotifyID = extractSpotifyIDFromURL(spotifyLink.URL)
+	}
+
+	// Check Tidal
+	if tidalLink, ok := songLinkResp.LinksByPlatform["tidal"]; ok && tidalLink.URL != "" {
+		availability.Tidal = true
+		availability.TidalURL = tidalLink.URL
+	}
+
+	// Check Amazon
+	if amazonLink, ok := songLinkResp.LinksByPlatform["amazonMusic"]; ok && amazonLink.URL != "" {
+		availability.Amazon = true
+		availability.AmazonURL = amazonLink.URL
+	}
+
+	// Check Deezer
+	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
+		availability.Deezer = true
+		availability.DeezerURL = deezerLink.URL
+		availability.DeezerID = extractDeezerIDFromURL(deezerLink.URL)
+	}
+
+	return availability, nil
+}
+
+// extractSpotifyIDFromURL extracts Spotify track ID from URL
+func extractSpotifyIDFromURL(spotifyURL string) string {
+	// URL format: https://open.spotify.com/track/0Jcij1eWd5bDMU5iPbxe2i
+	parts := strings.Split(spotifyURL, "/track/")
+	if len(parts) > 1 {
+		// Get the ID part and remove any query parameters
+		idPart := parts[1]
+		if idx := strings.Index(idPart, "?"); idx > 0 {
+			idPart = idPart[:idx]
+		}
+		return idPart
+	}
+	return ""
+}
+
+// GetSpotifyIDFromDeezer converts a Deezer track ID to Spotify track ID using SongLink
+func (s *SongLinkClient) GetSpotifyIDFromDeezer(deezerTrackID string) (string, error) {
+	availability, err := s.CheckAvailabilityFromDeezer(deezerTrackID)
+	if err != nil {
+		return "", err
+	}
+	
+	if availability.SpotifyID == "" {
+		return "", fmt.Errorf("track not found on Spotify")
+	}
+	
+	return availability.SpotifyID, nil
+}
+
+// GetTidalURLFromDeezer converts a Deezer track ID to Tidal URL using SongLink
+func (s *SongLinkClient) GetTidalURLFromDeezer(deezerTrackID string) (string, error) {
+	availability, err := s.CheckAvailabilityFromDeezer(deezerTrackID)
+	if err != nil {
+		return "", err
+	}
+	
+	if !availability.Tidal || availability.TidalURL == "" {
+		return "", fmt.Errorf("track not found on Tidal")
+	}
+	
+	return availability.TidalURL, nil
+}
+
+// GetAmazonURLFromDeezer converts a Deezer track ID to Amazon Music URL using SongLink
+func (s *SongLinkClient) GetAmazonURLFromDeezer(deezerTrackID string) (string, error) {
+	availability, err := s.CheckAvailabilityFromDeezer(deezerTrackID)
+	if err != nil {
+		return "", err
+	}
+	
+	if !availability.Amazon || availability.AmazonURL == "" {
+		return "", fmt.Errorf("track not found on Amazon Music")
+	}
+	
+	return availability.AmazonURL, nil
+}

go_backend/spotify.go

@@ -10,6 +10,7 @@ import (
 	"math/rand"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -20,11 +21,28 @@ const (
 	playlistBaseURL     = "https://api.spotify.com/v1/playlists/%s"
 	albumBaseURL        = "https://api.spotify.com/v1/albums/%s"
 	trackBaseURL        = "https://api.spotify.com/v1/tracks/%s"
+	artistBaseURL       = "https://api.spotify.com/v1/artists/%s"
+	artistAlbumsURL     = "https://api.spotify.com/v1/artists/%s/albums"
 	searchBaseURL       = "https://api.spotify.com/v1/search"
+	
+	// Cache TTL settings
+	artistCacheTTL = 10 * time.Minute
+	searchCacheTTL = 5 * time.Minute
+	albumCacheTTL  = 10 * time.Minute
 )
 
 var errInvalidSpotifyURL = errors.New("invalid or unsupported Spotify URL")
 
+// cacheEntry holds cached data with expiration
+type cacheEntry struct {
+	data      interface{}
+	expiresAt time.Time
+}
+
+func (e *cacheEntry) isExpired() bool {
+	return time.Now().After(e.expiresAt)
+}
+
 // SpotifyMetadataClient handles Spotify API interactions
 type SpotifyMetadataClient struct {
 	httpClient     *http.Client
@@ -32,31 +50,76 @@ type SpotifyMetadataClient struct {
 	clientSecret   string
 	cachedToken    string
 	tokenExpiresAt time.Time
+	tokenMu        sync.Mutex // Protects token cache for concurrent access
 	rng            *rand.Rand
 	rngMu          sync.Mutex
 	userAgent      string
+	
+	// Caches to reduce API calls
+	artistCache map[string]*cacheEntry // key: artistID
+	searchCache map[string]*cacheEntry // key: query+type
+	albumCache  map[string]*cacheEntry // key: albumID
+	cacheMu     sync.RWMutex
+}
+
+// Custom credentials storage (set from Flutter)
+var (
+	customClientID     string
+	customClientSecret string
+	credentialsMu      sync.RWMutex
+)
+
+// SetSpotifyCredentials sets custom Spotify API credentials
+// Pass empty strings to use default credentials
+func SetSpotifyCredentials(clientID, clientSecret string) {
+	credentialsMu.Lock()
+	defer credentialsMu.Unlock()
+	customClientID = clientID
+	customClientSecret = clientSecret
+}
+
+// getCredentials returns the current credentials (custom or default)
+func getCredentials() (string, string) {
+	credentialsMu.RLock()
+	defer credentialsMu.RUnlock()
+	
+	if customClientID != "" && customClientSecret != "" {
+		return customClientID, customClientSecret
+	}
+	
+	// Fall back to default credentials
+	clientID := os.Getenv("SPOTIFY_CLIENT_ID")
+	if clientID == "" {
+		if decoded, err := base64.StdEncoding.DecodeString("NWY1NzNjOTYyMDQ5NGJhZTg3ODkwYzBmMDhhNjAyOTM="); err == nil {
+			clientID = string(decoded)
+		}
+	}
+
+	clientSecret := os.Getenv("SPOTIFY_CLIENT_SECRET")
+	if clientSecret == "" {
+		if decoded, err := base64.StdEncoding.DecodeString("MjEyNDc2ZDliMGYzNDcyZWFhNzYyZDkwYjE5YjBiYTg="); err == nil {
+			clientSecret = string(decoded)
+		}
+	}
+	
+	return clientID, clientSecret
 }
 
 // NewSpotifyMetadataClient creates a new Spotify client
 func NewSpotifyMetadataClient() *SpotifyMetadataClient {
 	src := rand.NewSource(time.Now().UnixNano())
 
-	// Decode credentials from base64
-	clientID := ""
-	if decoded, err := base64.StdEncoding.DecodeString("NWY1NzNjOTYyMDQ5NGJhZTg3ODkwYzBmMDhhNjAyOTM="); err == nil {
-		clientID = string(decoded)
-	}
-
-	clientSecret := ""
-	if decoded, err := base64.StdEncoding.DecodeString("MjEyNDc2ZDliMGYzNDcyZWFhNzYyZDkwYjE5YjBiYTg="); err == nil {
-		clientSecret = string(decoded)
-	}
+	// Get credentials (custom or default)
+	clientID, clientSecret := getCredentials()
 
 	c := &SpotifyMetadataClient{
-		httpClient:   &http.Client{Timeout: 15 * time.Second},
+		httpClient:   NewHTTPClientWithTimeout(15 * time.Second), // Use shared transport for connection pooling
 		clientID:     clientID,
 		clientSecret: clientSecret,
 		rng:          rand.New(src),
+		artistCache:  make(map[string]*cacheEntry),
+		searchCache:  make(map[string]*cacheEntry),
+		albumCache:   make(map[string]*cacheEntry),
 	}
 	c.userAgent = c.randomUserAgent()
 	return c
@@ -131,6 +194,32 @@ type PlaylistResponsePayload struct {
 	TrackList    []AlbumTrackMetadata `json:"track_list"`
 }
 
+// ArtistInfoMetadata holds artist information
+type ArtistInfoMetadata struct {
+	ID         string `json:"id"`
+	Name       string `json:"name"`
+	Images     string `json:"images"`
+	Followers  int    `json:"followers"`
+	Popularity int    `json:"popularity"`
+}
+
+// ArtistAlbumMetadata holds album info for artist discography
+type ArtistAlbumMetadata struct {
+	ID          string `json:"id"`
+	Name        string `json:"name"`
+	ReleaseDate string `json:"release_date"`
+	TotalTracks int    `json:"total_tracks"`
+	Images      string `json:"images"`
+	AlbumType   string `json:"album_type"` // album, single, compilation
+	Artists     string `json:"artists"`
+}
+
+// ArtistResponsePayload is the response for artist requests
+type ArtistResponsePayload struct {
+	ArtistInfo ArtistInfoMetadata    `json:"artist_info"`
+	Albums     []ArtistAlbumMetadata `json:"albums"`
+}
+
 // TrackResponse is the response for single track requests
 type TrackResponse struct {
 	Track TrackMetadata `json:"track"`
@@ -142,6 +231,21 @@ type SearchResult struct {
 	Total  int             `json:"total"`
 }
 
+// SearchArtistResult represents an artist in search results
+type SearchArtistResult struct {
+	ID         string `json:"id"`
+	Name       string `json:"name"`
+	Images     string `json:"images"`
+	Followers  int    `json:"followers"`
+	Popularity int    `json:"popularity"`
+}
+
+// SearchAllResult represents combined search results for tracks and artists
+type SearchAllResult struct {
+	Tracks  []TrackMetadata      `json:"tracks"`
+	Artists []SearchArtistResult `json:"artists"`
+}
+
 type spotifyURI struct {
 	Type string
 	ID   string
@@ -212,6 +316,8 @@ func (c *SpotifyMetadataClient) GetFilteredData(ctx context.Context, spotifyURL
 		return c.fetchAlbum(ctx, parsed.ID, token)
 	case "playlist":
 		return c.fetchPlaylist(ctx, parsed.ID, token)
+	case "artist":
+		return c.fetchArtist(ctx, parsed.ID, token)
 	default:
 		return nil, fmt.Errorf("unsupported Spotify type: %s", parsed.Type)
 	}
@@ -263,6 +369,98 @@ func (c *SpotifyMetadataClient) SearchTracks(ctx context.Context, query string,
 	return result, nil
 }
 
+// SearchAll searches for tracks and artists on Spotify
+func (c *SpotifyMetadataClient) SearchAll(ctx context.Context, query string, trackLimit, artistLimit int) (*SearchAllResult, error) {
+	// Create cache key
+	cacheKey := fmt.Sprintf("all:%s:%d:%d", query, trackLimit, artistLimit)
+	
+	// Check cache first
+	c.cacheMu.RLock()
+	if entry, ok := c.searchCache[cacheKey]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*SearchAllResult), nil
+	}
+	c.cacheMu.RUnlock()
+
+	token, err := c.getAccessToken(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	searchURL := fmt.Sprintf("%s?q=%s&type=track,artist&limit=%d", searchBaseURL, url.QueryEscape(query), trackLimit)
+	
+	var response struct {
+		Tracks struct {
+			Items []trackFull `json:"items"`
+		} `json:"tracks"`
+		Artists struct {
+			Items []struct {
+				ID         string  `json:"id"`
+				Name       string  `json:"name"`
+				Images     []image `json:"images"`
+				Followers  struct {
+					Total int `json:"total"`
+				} `json:"followers"`
+				Popularity int `json:"popularity"`
+			} `json:"items"`
+		} `json:"artists"`
+	}
+	
+	if err := c.getJSON(ctx, searchURL, token, &response); err != nil {
+		return nil, err
+	}
+
+	result := &SearchAllResult{
+		Tracks:  make([]TrackMetadata, 0, len(response.Tracks.Items)),
+		Artists: make([]SearchArtistResult, 0, len(response.Artists.Items)),
+	}
+
+	for _, track := range response.Tracks.Items {
+		result.Tracks = append(result.Tracks, TrackMetadata{
+			SpotifyID:   track.ID,
+			Artists:     joinArtists(track.Artists),
+			Name:        track.Name,
+			AlbumName:   track.Album.Name,
+			AlbumArtist: joinArtists(track.Album.Artists),
+			DurationMS:  track.DurationMS,
+			Images:      firstImageURL(track.Album.Images),
+			ReleaseDate: track.Album.ReleaseDate,
+			TrackNumber: track.TrackNumber,
+			TotalTracks: track.Album.TotalTracks,
+			DiscNumber:  track.DiscNumber,
+			ExternalURL: track.ExternalURL.Spotify,
+			ISRC:        track.ExternalID.ISRC,
+		})
+	}
+
+	// Limit artists to artistLimit
+	artistCount := len(response.Artists.Items)
+	if artistCount > artistLimit {
+		artistCount = artistLimit
+	}
+	
+	for i := 0; i < artistCount; i++ {
+		artist := response.Artists.Items[i]
+		result.Artists = append(result.Artists, SearchArtistResult{
+			ID:         artist.ID,
+			Name:       artist.Name,
+			Images:     firstImageURL(artist.Images),
+			Followers:  artist.Followers.Total,
+			Popularity: artist.Popularity,
+		})
+	}
+
+	// Store in cache
+	c.cacheMu.Lock()
+	c.searchCache[cacheKey] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(searchCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	return result, nil
+}
+
 func (c *SpotifyMetadataClient) fetchTrack(ctx context.Context, trackID, token string) (*TrackResponse, error) {
 	var data trackFull
 	if err := c.getJSON(ctx, fmt.Sprintf(trackBaseURL, trackID), token, &data); err != nil {
@@ -289,6 +487,25 @@ func (c *SpotifyMetadataClient) fetchTrack(ctx context.Context, trackID, token s
 }
 
 func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token string) (*AlbumResponsePayload, error) {
+	// Check cache first
+	c.cacheMu.RLock()
+	if entry, ok := c.albumCache[albumID]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*AlbumResponsePayload), nil
+	}
+	c.cacheMu.RUnlock()
+
+	// Track item structure for pagination
+	type trackItem struct {
+		ID          string      `json:"id"`
+		Name        string      `json:"name"`
+		DurationMS  int         `json:"duration_ms"`
+		TrackNumber int         `json:"track_number"`
+		DiscNumber  int         `json:"disc_number"`
+		ExternalURL externalURL `json:"external_urls"`
+		Artists     []artist    `json:"artists"`
+	}
+
 	var data struct {
 		Name        string   `json:"name"`
 		ReleaseDate string   `json:"release_date"`
@@ -296,15 +513,8 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 		Images      []image  `json:"images"`
 		Artists     []artist `json:"artists"`
 		Tracks      struct {
-			Items []struct {
-				ID          string      `json:"id"`
-				Name        string      `json:"name"`
-				DurationMS  int         `json:"duration_ms"`
-				TrackNumber int         `json:"track_number"`
-				DiscNumber  int         `json:"disc_number"`
-				ExternalURL externalURL `json:"external_urls"`
-				Artists     []artist    `json:"artists"`
-			} `json:"items"`
+			Items []trackItem `json:"items"`
+			Next  string      `json:"next"`
 		} `json:"tracks"`
 	}
 
@@ -321,10 +531,38 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 		Images:      albumImage,
 	}
 
-	tracks := make([]AlbumTrackMetadata, 0, len(data.Tracks.Items))
-	for _, item := range data.Tracks.Items {
-		// Fetch ISRC for each track
-		isrc := c.fetchTrackISRC(ctx, item.ID, token)
+	// Collect all tracks (including paginated)
+	allTrackItems := data.Tracks.Items
+	nextURL := data.Tracks.Next
+	
+	// Fetch remaining tracks using pagination (no limit)
+	for nextURL != "" {
+		var pageData struct {
+			Items []trackItem `json:"items"`
+			Next  string      `json:"next"`
+		}
+		if err := c.getJSON(ctx, nextURL, token, &pageData); err != nil {
+			fmt.Printf("[Spotify] Warning: failed to fetch album tracks page: %v\n", err)
+			break
+		}
+		allTrackItems = append(allTrackItems, pageData.Items...)
+		nextURL = pageData.Next
+	}
+
+	fmt.Printf("[Spotify] Album has %d tracks (total: %d)\n", len(allTrackItems), data.TotalTracks)
+
+	// Collect track IDs for parallel ISRC fetching
+	trackIDs := make([]string, len(allTrackItems))
+	for i, item := range allTrackItems {
+		trackIDs[i] = item.ID
+	}
+
+	// Fetch ISRCs in parallel for ALL tracks (like Deezer implementation)
+	isrcMap := c.fetchISRCsParallel(ctx, trackIDs, token)
+
+	tracks := make([]AlbumTrackMetadata, 0, len(allTrackItems))
+	for _, item := range allTrackItems {
+		isrc := isrcMap[item.ID]
 		
 		tracks = append(tracks, AlbumTrackMetadata{
 			SpotifyID:   item.ID,
@@ -344,13 +582,65 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 		})
 	}
 
-	return &AlbumResponsePayload{
+	result := &AlbumResponsePayload{
 		AlbumInfo: info,
 		TrackList: tracks,
-	}, nil
+	}
+
+	// Store in cache
+	c.cacheMu.Lock()
+	c.albumCache[albumID] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(albumCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	return result, nil
+}
+
+// fetchISRCsParallel fetches ISRCs for multiple tracks in parallel
+// Similar to Deezer implementation for consistency
+func (c *SpotifyMetadataClient) fetchISRCsParallel(ctx context.Context, trackIDs []string, token string) map[string]string {
+	const maxParallelISRC = 10 // Max concurrent ISRC fetches
+	
+	result := make(map[string]string)
+	var resultMu sync.Mutex
+	
+	if len(trackIDs) == 0 {
+		return result
+	}
+	
+	// Use semaphore to limit concurrent requests
+	sem := make(chan struct{}, maxParallelISRC)
+	var wg sync.WaitGroup
+	
+	for _, trackID := range trackIDs {
+		wg.Add(1)
+		go func(id string) {
+			defer wg.Done()
+			
+			// Acquire semaphore
+			select {
+			case sem <- struct{}{}:
+				defer func() { <-sem }()
+			case <-ctx.Done():
+				return
+			}
+			
+			isrc := c.fetchTrackISRC(ctx, id, token)
+			
+			resultMu.Lock()
+			result[id] = isrc
+			resultMu.Unlock()
+		}(trackID)
+	}
+	
+	wg.Wait()
+	return result
 }
 
 func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, token string) (*PlaylistResponsePayload, error) {
+	// First request to get playlist info and first batch of tracks
 	var data struct {
 		Name   string  `json:"name"`
 		Images []image `json:"images"`
@@ -361,7 +651,8 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 			Items []struct {
 				Track *trackFull `json:"track"`
 			} `json:"items"`
-			Total int `json:"total"`
+			Total int    `json:"total"`
+			Next  string `json:"next"`
 		} `json:"tracks"`
 	}
 
@@ -375,7 +666,10 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 	info.Owner.Name = data.Name
 	info.Owner.Images = firstImageURL(data.Images)
 
-	tracks := make([]AlbumTrackMetadata, 0, len(data.Tracks.Items))
+	// Pre-allocate with expected capacity
+	tracks := make([]AlbumTrackMetadata, 0, data.Tracks.Total)
+	
+	// Add first batch of tracks
 	for _, item := range data.Tracks.Items {
 		if item.Track == nil {
 			continue
@@ -399,12 +693,157 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 		})
 	}
 
+	// Fetch remaining tracks using pagination (NO LIMIT - fetch all tracks)
+	nextURL := data.Tracks.Next
+	
+	for nextURL != "" {
+		var pageData struct {
+			Items []struct {
+				Track *trackFull `json:"track"`
+			} `json:"items"`
+			Next string `json:"next"`
+		}
+
+		if err := c.getJSON(ctx, nextURL, token, &pageData); err != nil {
+			// Log error but return what we have so far
+			fmt.Printf("[Spotify] Warning: failed to fetch page, returning %d tracks: %v\n", len(tracks), err)
+			break
+		}
+
+		for _, item := range pageData.Items {
+			if item.Track == nil {
+				continue
+			}
+			tracks = append(tracks, AlbumTrackMetadata{
+				SpotifyID:   item.Track.ID,
+				Artists:     joinArtists(item.Track.Artists),
+				Name:        item.Track.Name,
+				AlbumName:   item.Track.Album.Name,
+				AlbumArtist: joinArtists(item.Track.Album.Artists),
+				DurationMS:  item.Track.DurationMS,
+				Images:      firstImageURL(item.Track.Album.Images),
+				ReleaseDate: item.Track.Album.ReleaseDate,
+				TrackNumber: item.Track.TrackNumber,
+				TotalTracks: item.Track.Album.TotalTracks,
+				DiscNumber:  item.Track.DiscNumber,
+				ExternalURL: item.Track.ExternalURL.Spotify,
+				ISRC:        item.Track.ExternalID.ISRC,
+				AlbumID:     item.Track.Album.ID,
+				AlbumURL:    item.Track.Album.ExternalURL.Spotify,
+			})
+		}
+
+		nextURL = pageData.Next
+	}
+
+	fmt.Printf("[Spotify] Fetched %d tracks from playlist (total: %d)\n", len(tracks), data.Tracks.Total)
+
 	return &PlaylistResponsePayload{
 		PlaylistInfo: info,
 		TrackList:    tracks,
 	}, nil
 }
 
+func (c *SpotifyMetadataClient) fetchArtist(ctx context.Context, artistID, token string) (*ArtistResponsePayload, error) {
+	// Check cache first
+	c.cacheMu.RLock()
+	if entry, ok := c.artistCache[artistID]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*ArtistResponsePayload), nil
+	}
+	c.cacheMu.RUnlock()
+
+	// Fetch artist info
+	var artistData struct {
+		ID         string  `json:"id"`
+		Name       string  `json:"name"`
+		Images     []image `json:"images"`
+		Followers  struct {
+			Total int `json:"total"`
+		} `json:"followers"`
+		Popularity int `json:"popularity"`
+	}
+
+	if err := c.getJSON(ctx, fmt.Sprintf(artistBaseURL, artistID), token, &artistData); err != nil {
+		return nil, err
+	}
+
+	artistInfo := ArtistInfoMetadata{
+		ID:         artistData.ID,
+		Name:       artistData.Name,
+		Images:     firstImageURL(artistData.Images),
+		Followers:  artistData.Followers.Total,
+		Popularity: artistData.Popularity,
+	}
+
+	// Fetch artist albums (all types: album, single, compilation)
+	albums := make([]ArtistAlbumMetadata, 0)
+	offset := 0
+	limit := 50
+
+	for {
+		albumsURL := fmt.Sprintf("%s?include_groups=album,single,compilation&limit=%d&offset=%d",
+			fmt.Sprintf(artistAlbumsURL, artistID), limit, offset)
+
+		var albumsData struct {
+			Items []struct {
+				ID          string      `json:"id"`
+				Name        string      `json:"name"`
+				ReleaseDate string      `json:"release_date"`
+				TotalTracks int         `json:"total_tracks"`
+				Images      []image     `json:"images"`
+				AlbumType   string      `json:"album_type"`
+				Artists     []artist    `json:"artists"`
+				ExternalURL externalURL `json:"external_urls"`
+			} `json:"items"`
+			Next  string `json:"next"`
+			Total int    `json:"total"`
+		}
+
+		if err := c.getJSON(ctx, albumsURL, token, &albumsData); err != nil {
+			return nil, err
+		}
+
+		for _, album := range albumsData.Items {
+			albums = append(albums, ArtistAlbumMetadata{
+				ID:          album.ID,
+				Name:        album.Name,
+				ReleaseDate: album.ReleaseDate,
+				TotalTracks: album.TotalTracks,
+				Images:      firstImageURL(album.Images),
+				AlbumType:   album.AlbumType,
+				Artists:     joinArtists(album.Artists),
+			})
+		}
+
+		// Check if there are more albums
+		if albumsData.Next == "" || len(albumsData.Items) < limit {
+			break
+		}
+		offset += limit
+
+		// Safety limit to prevent infinite loops
+		if offset > 500 {
+			break
+		}
+	}
+
+	result := &ArtistResponsePayload{
+		ArtistInfo: artistInfo,
+		Albums:     albums,
+	}
+
+	// Store in cache
+	c.cacheMu.Lock()
+	c.artistCache[artistID] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(artistCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	return result, nil
+}
+
 func (c *SpotifyMetadataClient) fetchTrackISRC(ctx context.Context, trackID, token string) string {
 	var data struct {
 		ExternalID externalID `json:"external_ids"`
@@ -465,8 +904,16 @@ func (c *SpotifyMetadataClient) getJSON(ctx context.Context, endpoint, token str
 		return err
 	}
 
+	// Set headers (same as PC version baseHeaders)
 	req.Header.Set("User-Agent", c.userAgent)
 	req.Header.Set("Accept", "application/json")
+	req.Header.Set("Accept-Language", "en-US,en;q=0.9")
+	req.Header.Set("sec-ch-ua-platform", "\"Windows\"")
+	req.Header.Set("sec-fetch-dest", "empty")
+	req.Header.Set("sec-fetch-mode", "cors")
+	req.Header.Set("sec-fetch-site", "same-origin")
+	req.Header.Set("Referer", "https://open.spotify.com/")
+	req.Header.Set("Origin", "https://open.spotify.com")
 	if token != "" {
 		req.Header.Set("Authorization", "Bearer "+token)
 	}
@@ -493,13 +940,23 @@ func (c *SpotifyMetadataClient) randomUserAgent() string {
 	c.rngMu.Lock()
 	defer c.rngMu.Unlock()
 
-	chromeMajor := 80 + c.rng.Intn(25)
-	chromeBuild := 3000 + c.rng.Intn(1500)
-	chromePatch := 60 + c.rng.Intn(65)
+	// Use Mac User-Agent format (same as PC version)
+	macMajor := c.rng.Intn(4) + 11    // 11-14
+	macMinor := c.rng.Intn(5) + 4     // 4-8
+	webkitMajor := c.rng.Intn(7) + 530 // 530-536
+	webkitMinor := c.rng.Intn(7) + 30  // 30-36
+	chromeMajor := c.rng.Intn(25) + 80 // 80-104
+	chromeBuild := c.rng.Intn(1500) + 3000 // 3000-4499
+	chromePatch := c.rng.Intn(65) + 60 // 60-124
+	safariMajor := c.rng.Intn(7) + 530 // 530-536
+	safariMinor := c.rng.Intn(6) + 30  // 30-35
 
 	return fmt.Sprintf(
-		"Mozilla/5.0 (Linux; Android 12) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Mobile Safari/537.36",
+		"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_%d_%d) AppleWebKit/%d.%d (KHTML, like Gecko) Chrome/%d.0.%d.%d Safari/%d.%d",
+		macMajor, macMinor,
+		webkitMajor, webkitMinor,
 		chromeMajor, chromeBuild, chromePatch,
+		safariMajor, safariMinor,
 	)
 }
 

ios/Runner.xcodeproj/project.pbxproj

@@ -427,7 +427,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
+				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = AppIcon;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
 				CLANG_CXX_LIBRARY = "libc++";
@@ -484,7 +484,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = YES;
+				ASSETCATALOG_COMPILER_GENERATE_SWIFT_ASSET_SYMBOL_EXTENSIONS = AppIcon;
 				CLANG_ANALYZER_NONNULL = YES;
 				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
 				CLANG_CXX_LIBRARY = "libc++";

ios/Runner/AppDelegate.swift

@@ -66,6 +66,15 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "searchSpotifyAll":
+            let args = call.arguments as! [String: Any]
+            let query = args["query"] as! String
+            let trackLimit = args["track_limit"] as? Int ?? 15
+            let artistLimit = args["artist_limit"] as? Int ?? 3
+            let response = GobackendSearchSpotifyAll(query, Int(trackLimit), Int(artistLimit), &error)
+            if let error = error { throw error }
+            return response
+            
         case "checkAvailability":
             let args = call.arguments as! [String: Any]
             let spotifyId = args["spotify_id"] as! String
@@ -90,6 +99,28 @@ import Gobackend  // Import Go framework
             let response = GobackendGetDownloadProgress()
             return response
             
+        case "getAllDownloadProgress":
+            let response = GobackendGetAllDownloadProgress()
+            return response
+            
+        case "initItemProgress":
+            let args = call.arguments as! [String: Any]
+            let itemId = args["item_id"] as! String
+            GobackendInitItemProgress(itemId)
+            return nil
+            
+        case "finishItemProgress":
+            let args = call.arguments as! [String: Any]
+            let itemId = args["item_id"] as! String
+            GobackendFinishItemProgress(itemId)
+            return nil
+            
+        case "clearItemProgress":
+            let args = call.arguments as! [String: Any]
+            let itemId = args["item_id"] as! String
+            GobackendClearItemProgress(itemId)
+            return nil
+            
         case "setDownloadDirectory":
             let args = call.arguments as! [String: Any]
             let path = args["path"] as! String
@@ -133,7 +164,8 @@ import Gobackend  // Import Go framework
             let spotifyId = args["spotify_id"] as! String
             let trackName = args["track_name"] as! String
             let artistName = args["artist_name"] as! String
-            let response = GobackendGetLyricsLRC(spotifyId, trackName, artistName, &error)
+            let filePath = args["file_path"] as? String ?? ""
+            let response = GobackendGetLyricsLRC(spotifyId, trackName, artistName, filePath, &error)
             if let error = error { throw error }
             return response
             
@@ -145,6 +177,110 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "cleanupConnections":
+            GobackendCleanupConnections()
+            return nil
+            
+        case "readFileMetadata":
+            let args = call.arguments as! [String: Any]
+            let filePath = args["file_path"] as! String
+            let response = GobackendReadFileMetadata(filePath, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "searchDeezerAll":
+            let args = call.arguments as! [String: Any]
+            let query = args["query"] as! String
+            let trackLimit = args["track_limit"] as? Int ?? 15
+            let artistLimit = args["artist_limit"] as? Int ?? 3
+            let response = GobackendSearchDeezerAll(query, Int(trackLimit), Int(artistLimit), &error)
+            if let error = error { throw error }
+            return response
+
+        case "getDeezerMetadata":
+            let args = call.arguments as! [String: Any]
+            let resourceType = args["resource_type"] as! String
+            let resourceId = args["resource_id"] as! String
+            let response = GobackendGetDeezerMetadata(resourceType, resourceId, &error)
+            if let error = error { throw error }
+            return response
+
+        case "parseDeezerUrl":
+            let args = call.arguments as! [String: Any]
+            let url = args["url"] as! String
+            let response = GobackendParseDeezerURLExport(url, &error)
+            if let error = error { throw error }
+            return response
+
+        case "searchDeezerByISRC":
+            let args = call.arguments as! [String: Any]
+            let isrc = args["isrc"] as! String
+            let response = GobackendSearchDeezerByISRC(isrc, &error)
+            if let error = error { throw error }
+            return response
+
+        case "convertSpotifyToDeezer":
+            let args = call.arguments as! [String: Any]
+            let resourceType = args["resource_type"] as! String
+            let spotifyId = args["spotify_id"] as! String
+            let response = GobackendConvertSpotifyToDeezer(resourceType, spotifyId, &error)
+            if let error = error { throw error }
+            return response
+
+        case "getSpotifyMetadataWithFallback":
+            let args = call.arguments as! [String: Any]
+            let url = args["url"] as! String
+            let response = GobackendGetSpotifyMetadataWithDeezerFallback(url, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "preWarmTrackCache":
+            let args = call.arguments as! [String: Any]
+            let tracksJson = args["tracks"] as! String
+            let _ = GobackendPreWarmTrackCacheJSON(tracksJson, &error)
+            if let error = error { throw error }
+            return nil
+            
+        case "getTrackCacheSize":
+            let response = GobackendGetTrackCacheSize()
+            return response
+            
+        case "clearTrackCache":
+            GobackendClearTrackCache()
+            return nil
+            
+        case "setSpotifyCredentials":
+            let args = call.arguments as! [String: Any]
+            let clientId = args["client_id"] as! String
+            let clientSecret = args["client_secret"] as! String
+            GobackendSetSpotifyAPICredentials(clientId, clientSecret)
+            return nil
+            
+        // Log methods
+        case "getLogs":
+            let response = GobackendGetLogs()
+            return response
+            
+        case "getLogsSince":
+            let args = call.arguments as! [String: Any]
+            let index = args["index"] as? Int ?? 0
+            let response = GobackendGetLogsSince(Int(index))
+            return response
+            
+        case "clearLogs":
+            GobackendClearLogs()
+            return nil
+            
+        case "getLogCount":
+            let response = GobackendGetLogCount()
+            return response
+            
+        case "setLoggingEnabled":
+            let args = call.arguments as! [String: Any]
+            let enabled = args["enabled"] as? Bool ?? false
+            GobackendSetLoggingEnabled(enabled)
+            return nil
+            
         default:
             throw NSError(
                 domain: "SpotiFLAC",

ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,122 +1 @@
-{
-  "images" : [
-    {
-      "size" : "20x20",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-20x20@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "20x20",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-20x20@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-29x29@1x.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-29x29@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-29x29@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-40x40@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-40x40@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "60x60",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-60x60@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "60x60",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-60x60@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "20x20",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-20x20@1x.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "20x20",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-20x20@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-29x29@1x.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-29x29@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-40x40@1x.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-40x40@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "76x76",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-76x76@1x.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "76x76",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-76x76@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "83.5x83.5",
-      "idiom" : "ipad",
-      "filename" : "Icon-App-83.5x83.5@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "1024x1024",
-      "idiom" : "ios-marketing",
-      "filename" : "Icon-App-1024x1024@1x.png",
-      "scale" : "1x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}
+{"images":[{"size":"20x20","idiom":"iphone","filename":"Icon-App-20x20@2x.png","scale":"2x"},{"size":"20x20","idiom":"iphone","filename":"Icon-App-20x20@3x.png","scale":"3x"},{"size":"29x29","idiom":"iphone","filename":"Icon-App-29x29@1x.png","scale":"1x"},{"size":"29x29","idiom":"iphone","filename":"Icon-App-29x29@2x.png","scale":"2x"},{"size":"29x29","idiom":"iphone","filename":"Icon-App-29x29@3x.png","scale":"3x"},{"size":"40x40","idiom":"iphone","filename":"Icon-App-40x40@2x.png","scale":"2x"},{"size":"40x40","idiom":"iphone","filename":"Icon-App-40x40@3x.png","scale":"3x"},{"size":"57x57","idiom":"iphone","filename":"Icon-App-57x57@1x.png","scale":"1x"},{"size":"57x57","idiom":"iphone","filename":"Icon-App-57x57@2x.png","scale":"2x"},{"size":"60x60","idiom":"iphone","filename":"Icon-App-60x60@2x.png","scale":"2x"},{"size":"60x60","idiom":"iphone","filename":"Icon-App-60x60@3x.png","scale":"3x"},{"size":"20x20","idiom":"ipad","filename":"Icon-App-20x20@1x.png","scale":"1x"},{"size":"20x20","idiom":"ipad","filename":"Icon-App-20x20@2x.png","scale":"2x"},{"size":"29x29","idiom":"ipad","filename":"Icon-App-29x29@1x.png","scale":"1x"},{"size":"29x29","idiom":"ipad","filename":"Icon-App-29x29@2x.png","scale":"2x"},{"size":"40x40","idiom":"ipad","filename":"Icon-App-40x40@1x.png","scale":"1x"},{"size":"40x40","idiom":"ipad","filename":"Icon-App-40x40@2x.png","scale":"2x"},{"size":"50x50","idiom":"ipad","filename":"Icon-App-50x50@1x.png","scale":"1x"},{"size":"50x50","idiom":"ipad","filename":"Icon-App-50x50@2x.png","scale":"2x"},{"size":"72x72","idiom":"ipad","filename":"Icon-App-72x72@1x.png","scale":"1x"},{"size":"72x72","idiom":"ipad","filename":"Icon-App-72x72@2x.png","scale":"2x"},{"size":"76x76","idiom":"ipad","filename":"Icon-App-76x76@1x.png","scale":"1x"},{"size":"76x76","idiom":"ipad","filename":"Icon-App-76x76@2x.png","scale":"2x"},{"size":"83.5x83.5","idiom":"ipad","filename":"Icon-App-83.5x83.5@2x.png","scale":"2x"},{"size":"1024x1024","idiom":"ios-marketing","filename":"Icon-App-1024x1024@1x.png","scale":"1x"}],"info":{"version":1,"author":"xcode"}}

lib/app.dart

@@ -7,10 +7,11 @@ import 'package:spotiflac_android/providers/settings_provider.dart';
 import 'package:spotiflac_android/theme/dynamic_color_wrapper.dart';
 
 final _routerProvider = Provider<GoRouter>((ref) {
-  final settings = ref.watch(settingsProvider);
+  // Only watch isFirstLaunch to prevent router rebuild on other settings changes
+  final isFirstLaunch = ref.watch(settingsProvider.select((s) => s.isFirstLaunch));
   
   return GoRouter(
-    initialLocation: settings.isFirstLaunch ? '/setup' : '/',
+    initialLocation: isFirstLaunch ? '/setup' : '/',
     routes: [
       GoRoute(
         path: '/',

lib/constants/app_info.dart

@@ -0,0 +1,20 @@
+/// App version and info constants
+/// Update version here only - all other files will reference this
+class AppInfo {
+  static const String version = '2.2.7';
+  static const String buildNumber = '49';
+  static const String fullVersion = '$version+$buildNumber';
+  
+  
+  static const String appName = 'SpotiFLAC';
+  static const String copyright = '© 2026 SpotiFLAC';
+  
+  static const String mobileAuthor = 'zarzet';
+  static const String originalAuthor = 'afkarxyz';
+  
+  static const String githubRepo = 'zarzet/SpotiFLAC-Mobile';
+  static const String githubUrl = 'https://github.com/$githubRepo';
+  static const String originalGithubUrl = 'https://github.com/afkarxyz/SpotiFLAC';
+  
+  static const String kofiUrl = 'https://ko-fi.com/zarzet';
+}

lib/main.dart

@@ -1,12 +1,37 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:spotiflac_android/app.dart';
+import 'package:spotiflac_android/providers/download_queue_provider.dart';
+import 'package:spotiflac_android/services/notification_service.dart';
+import 'package:spotiflac_android/services/share_intent_service.dart';
 
-void main() {
+void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  
+  // Initialize notification service
+  await NotificationService().initialize();
+  
+  // Initialize share intent service
+  await ShareIntentService().initialize();
+  
   runApp(
-    const ProviderScope(
-      child: SpotiFLACApp(),
+    ProviderScope(
+      child: const _EagerInitialization(
+        child: SpotiFLACApp(),
+      ),
     ),
   );
 }
+
+/// Widget to eagerly initialize providers that need to load data on startup
+class _EagerInitialization extends ConsumerWidget {
+  const _EagerInitialization({required this.child});
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Eagerly initialize download history provider to load from storage
+    ref.watch(downloadHistoryProvider);
+    return child;
+  }
+}

lib/models/download_item.dart

@@ -7,11 +7,20 @@ part 'download_item.g.dart';
 enum DownloadStatus {
   queued,
   downloading,
+  finalizing, // Embedding metadata, cover, lyrics
   completed,
   failed,
   skipped,
 }
 
+/// Error type enum for better error handling
+enum DownloadErrorType {
+  unknown,
+  notFound,    // Track not found on any service
+  rateLimit,   // Rate limited by service
+  network,     // Network/connection error
+}
+
 @JsonSerializable()
 class DownloadItem {
   final String id;
@@ -19,9 +28,12 @@ class DownloadItem {
   final String service;
   final DownloadStatus status;
   final double progress;
+  final double speedMBps; // Download speed in MB/s
   final String? filePath;
   final String? error;
+  final DownloadErrorType? errorType;
   final DateTime createdAt;
+  final String? qualityOverride; // Override quality for this specific download
 
   const DownloadItem({
     required this.id,
@@ -29,9 +41,12 @@ class DownloadItem {
     required this.service,
     this.status = DownloadStatus.queued,
     this.progress = 0.0,
+    this.speedMBps = 0.0,
     this.filePath,
     this.error,
+    this.errorType,
     required this.createdAt,
+    this.qualityOverride,
   });
 
   DownloadItem copyWith({
@@ -40,9 +55,12 @@ class DownloadItem {
     String? service,
     DownloadStatus? status,
     double? progress,
+    double? speedMBps,
     String? filePath,
     String? error,
+    DownloadErrorType? errorType,
     DateTime? createdAt,
+    String? qualityOverride,
   }) {
     return DownloadItem(
       id: id ?? this.id,
@@ -50,12 +68,31 @@ class DownloadItem {
       service: service ?? this.service,
       status: status ?? this.status,
       progress: progress ?? this.progress,
+      speedMBps: speedMBps ?? this.speedMBps,
       filePath: filePath ?? this.filePath,
       error: error ?? this.error,
+      errorType: errorType ?? this.errorType,
       createdAt: createdAt ?? this.createdAt,
+      qualityOverride: qualityOverride ?? this.qualityOverride,
     );
   }
 
+  /// Get user-friendly error message based on error type
+  String get errorMessage {
+    if (error == null) return '';
+    
+    switch (errorType) {
+      case DownloadErrorType.notFound:
+        return 'Song not found on any service';
+      case DownloadErrorType.rateLimit:
+        return 'Rate limit reached, try again later';
+      case DownloadErrorType.network:
+        return 'Connection failed, check your internet';
+      default:
+        return error ?? 'An error occurred';
+    }
+  }
+
   factory DownloadItem.fromJson(Map<String, dynamic> json) =>
       _$DownloadItemFromJson(json);
   Map<String, dynamic> toJson() => _$DownloadItemToJson(this);

lib/models/download_item.g.dart

@@ -14,9 +14,12 @@ DownloadItem _$DownloadItemFromJson(Map<String, dynamic> json) => DownloadItem(
       $enumDecodeNullable(_$DownloadStatusEnumMap, json['status']) ??
       DownloadStatus.queued,
   progress: (json['progress'] as num?)?.toDouble() ?? 0.0,
+  speedMBps: (json['speedMBps'] as num?)?.toDouble() ?? 0.0,
   filePath: json['filePath'] as String?,
   error: json['error'] as String?,
+  errorType: $enumDecodeNullable(_$DownloadErrorTypeEnumMap, json['errorType']),
   createdAt: DateTime.parse(json['createdAt'] as String),
+  qualityOverride: json['qualityOverride'] as String?,
 );
 
 Map<String, dynamic> _$DownloadItemToJson(DownloadItem instance) =>
@@ -26,15 +29,26 @@ Map<String, dynamic> _$DownloadItemToJson(DownloadItem instance) =>
       'service': instance.service,
       'status': _$DownloadStatusEnumMap[instance.status]!,
       'progress': instance.progress,
+      'speedMBps': instance.speedMBps,
       'filePath': instance.filePath,
       'error': instance.error,
+      'errorType': _$DownloadErrorTypeEnumMap[instance.errorType],
       'createdAt': instance.createdAt.toIso8601String(),
+      'qualityOverride': instance.qualityOverride,
     };
 
 const _$DownloadStatusEnumMap = {
   DownloadStatus.queued: 'queued',
   DownloadStatus.downloading: 'downloading',
+  DownloadStatus.finalizing: 'finalizing',
   DownloadStatus.completed: 'completed',
   DownloadStatus.failed: 'failed',
   DownloadStatus.skipped: 'skipped',
 };
+
+const _$DownloadErrorTypeEnumMap = {
+  DownloadErrorType.unknown: 'unknown',
+  DownloadErrorType.notFound: 'notFound',
+  DownloadErrorType.rateLimit: 'rateLimit',
+  DownloadErrorType.network: 'network',
+};

lib/models/settings.dart

@@ -13,6 +13,17 @@ class AppSettings {
   final bool maxQualityCover;
   final bool isFirstLaunch;
   final int concurrentDownloads; // 1 = sequential (default), max 3
+  final bool checkForUpdates; // Check for updates on app start
+  final String updateChannel; // stable, preview
+  final bool hasSearchedBefore; // Hide helper text after first search
+  final String folderOrganization; // none, artist, album, artist_album
+  final String historyViewMode; // list, grid
+  final bool askQualityBeforeDownload; // Show quality picker before each download
+  final String spotifyClientId; // Custom Spotify client ID (empty = use default)
+  final String spotifyClientSecret; // Custom Spotify client secret (empty = use default)
+  final bool useCustomSpotifyCredentials; // Whether to use custom credentials (if set)
+  final String metadataSource; // spotify, deezer - source for search and metadata
+  final bool enableLogging; // Enable detailed logging for debugging
 
   const AppSettings({
     this.defaultService = 'tidal',
@@ -24,6 +35,17 @@ class AppSettings {
     this.maxQualityCover = true,
     this.isFirstLaunch = true,
     this.concurrentDownloads = 1, // Default: sequential (off)
+    this.checkForUpdates = true, // Default: enabled
+    this.updateChannel = 'stable', // Default: stable releases only
+    this.hasSearchedBefore = false, // Default: show helper text
+    this.folderOrganization = 'none', // Default: no folder organization
+    this.historyViewMode = 'grid', // Default: grid view
+    this.askQualityBeforeDownload = true, // Default: ask quality before download
+    this.spotifyClientId = '', // Default: use built-in credentials
+    this.spotifyClientSecret = '', // Default: use built-in credentials
+    this.useCustomSpotifyCredentials = true, // Default: use custom if set
+    this.metadataSource = 'deezer', // Default: Deezer (no rate limit)
+    this.enableLogging = false, // Default: disabled for performance
   });
 
   AppSettings copyWith({
@@ -36,6 +58,17 @@ class AppSettings {
     bool? maxQualityCover,
     bool? isFirstLaunch,
     int? concurrentDownloads,
+    bool? checkForUpdates,
+    String? updateChannel,
+    bool? hasSearchedBefore,
+    String? folderOrganization,
+    String? historyViewMode,
+    bool? askQualityBeforeDownload,
+    String? spotifyClientId,
+    String? spotifyClientSecret,
+    bool? useCustomSpotifyCredentials,
+    String? metadataSource,
+    bool? enableLogging,
   }) {
     return AppSettings(
       defaultService: defaultService ?? this.defaultService,
@@ -47,6 +80,17 @@ class AppSettings {
       maxQualityCover: maxQualityCover ?? this.maxQualityCover,
       isFirstLaunch: isFirstLaunch ?? this.isFirstLaunch,
       concurrentDownloads: concurrentDownloads ?? this.concurrentDownloads,
+      checkForUpdates: checkForUpdates ?? this.checkForUpdates,
+      updateChannel: updateChannel ?? this.updateChannel,
+      hasSearchedBefore: hasSearchedBefore ?? this.hasSearchedBefore,
+      folderOrganization: folderOrganization ?? this.folderOrganization,
+      historyViewMode: historyViewMode ?? this.historyViewMode,
+      askQualityBeforeDownload: askQualityBeforeDownload ?? this.askQualityBeforeDownload,
+      spotifyClientId: spotifyClientId ?? this.spotifyClientId,
+      spotifyClientSecret: spotifyClientSecret ?? this.spotifyClientSecret,
+      useCustomSpotifyCredentials: useCustomSpotifyCredentials ?? this.useCustomSpotifyCredentials,
+      metadataSource: metadataSource ?? this.metadataSource,
+      enableLogging: enableLogging ?? this.enableLogging,
     );
   }
 

lib/models/settings.g.dart

@@ -16,6 +16,18 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   maxQualityCover: json['maxQualityCover'] as bool? ?? true,
   isFirstLaunch: json['isFirstLaunch'] as bool? ?? true,
   concurrentDownloads: (json['concurrentDownloads'] as num?)?.toInt() ?? 1,
+  checkForUpdates: json['checkForUpdates'] as bool? ?? true,
+  updateChannel: json['updateChannel'] as String? ?? 'stable',
+  hasSearchedBefore: json['hasSearchedBefore'] as bool? ?? false,
+  folderOrganization: json['folderOrganization'] as String? ?? 'none',
+  historyViewMode: json['historyViewMode'] as String? ?? 'grid',
+  askQualityBeforeDownload: json['askQualityBeforeDownload'] as bool? ?? true,
+  spotifyClientId: json['spotifyClientId'] as String? ?? '',
+  spotifyClientSecret: json['spotifyClientSecret'] as String? ?? '',
+  useCustomSpotifyCredentials:
+      json['useCustomSpotifyCredentials'] as bool? ?? true,
+  metadataSource: json['metadataSource'] as String? ?? 'deezer',
+  enableLogging: json['enableLogging'] as bool? ?? false,
 );
 
 Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
@@ -29,4 +41,15 @@ Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
       'maxQualityCover': instance.maxQualityCover,
       'isFirstLaunch': instance.isFirstLaunch,
       'concurrentDownloads': instance.concurrentDownloads,
+      'checkForUpdates': instance.checkForUpdates,
+      'updateChannel': instance.updateChannel,
+      'hasSearchedBefore': instance.hasSearchedBefore,
+      'folderOrganization': instance.folderOrganization,
+      'historyViewMode': instance.historyViewMode,
+      'askQualityBeforeDownload': instance.askQualityBeforeDownload,
+      'spotifyClientId': instance.spotifyClientId,
+      'spotifyClientSecret': instance.spotifyClientSecret,
+      'useCustomSpotifyCredentials': instance.useCustomSpotifyCredentials,
+      'metadataSource': instance.metadataSource,
+      'enableLogging': instance.enableLogging,
     };

lib/models/theme_settings.dart

@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 const String kThemeModeKey = 'theme_mode';
 const String kUseDynamicColorKey = 'use_dynamic_color';
 const String kSeedColorKey = 'seed_color';
+const String kUseAmoledKey = 'use_amoled';
 
 /// Default Spotify green color for fallback
 const int kDefaultSeedColor = 0xFF1DB954;
@@ -13,11 +14,13 @@ class ThemeSettings {
   final ThemeMode themeMode;
   final bool useDynamicColor;
   final int seedColorValue;
+  final bool useAmoled; // Pure black background for OLED screens
 
   const ThemeSettings({
     this.themeMode = ThemeMode.system,
     this.useDynamicColor = true,
     this.seedColorValue = kDefaultSeedColor,
+    this.useAmoled = false,
   });
 
   /// Get seed color as Color object
@@ -28,11 +31,13 @@ class ThemeSettings {
     ThemeMode? themeMode,
     bool? useDynamicColor,
     int? seedColorValue,
+    bool? useAmoled,
   }) {
     return ThemeSettings(
       themeMode: themeMode ?? this.themeMode,
       useDynamicColor: useDynamicColor ?? this.useDynamicColor,
       seedColorValue: seedColorValue ?? this.seedColorValue,
+      useAmoled: useAmoled ?? this.useAmoled,
     );
   }
 
@@ -41,6 +46,7 @@ class ThemeSettings {
         kThemeModeKey: themeMode.name,
         kUseDynamicColorKey: useDynamicColor,
         kSeedColorKey: seedColorValue,
+        kUseAmoledKey: useAmoled,
       };
 
   /// Create from JSON map
@@ -49,6 +55,7 @@ class ThemeSettings {
       themeMode: _themeModeFromString(json[kThemeModeKey] as String?),
       useDynamicColor: json[kUseDynamicColorKey] as bool? ?? true,
       seedColorValue: json[kSeedColorKey] as int? ?? kDefaultSeedColor,
+      useAmoled: json[kUseAmoledKey] as bool? ?? false,
     );
   }
 
@@ -58,12 +65,13 @@ class ThemeSettings {
     return other is ThemeSettings &&
         other.themeMode == themeMode &&
         other.useDynamicColor == useDynamicColor &&
-        other.seedColorValue == seedColorValue;
+        other.seedColorValue == seedColorValue &&
+        other.useAmoled == useAmoled;
   }
 
   @override
   int get hashCode =>
-      themeMode.hashCode ^ useDynamicColor.hashCode ^ seedColorValue.hashCode;
+      themeMode.hashCode ^ useDynamicColor.hashCode ^ seedColorValue.hashCode ^ useAmoled.hashCode;
 }
 
 /// Helper to convert string to ThemeMode

lib/models/track.dart

@@ -16,6 +16,7 @@ class Track {
   final int? trackNumber;
   final int? discNumber;
   final String? releaseDate;
+  final String? deezerId;
   final ServiceAvailability? availability;
 
   const Track({
@@ -30,6 +31,7 @@ class Track {
     this.trackNumber,
     this.discNumber,
     this.releaseDate,
+    this.deezerId,
     this.availability,
   });
 
@@ -42,17 +44,23 @@ class ServiceAvailability {
   final bool tidal;
   final bool qobuz;
   final bool amazon;
+  final bool deezer;
   final String? tidalUrl;
   final String? qobuzUrl;
   final String? amazonUrl;
+  final String? deezerUrl;
+  final String? deezerId;
 
   const ServiceAvailability({
     this.tidal = false,
     this.qobuz = false,
     this.amazon = false,
+    this.deezer = false,
     this.tidalUrl,
     this.qobuzUrl,
     this.amazonUrl,
+    this.deezerUrl,
+    this.deezerId,
   });
 
   factory ServiceAvailability.fromJson(Map<String, dynamic> json) =>

lib/models/track.g.dart

@@ -18,6 +18,7 @@ Track _$TrackFromJson(Map<String, dynamic> json) => Track(
   trackNumber: (json['trackNumber'] as num?)?.toInt(),
   discNumber: (json['discNumber'] as num?)?.toInt(),
   releaseDate: json['releaseDate'] as String?,
+  deezerId: json['deezerId'] as String?,
   availability: json['availability'] == null
       ? null
       : ServiceAvailability.fromJson(
@@ -37,6 +38,7 @@ Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
   'trackNumber': instance.trackNumber,
   'discNumber': instance.discNumber,
   'releaseDate': instance.releaseDate,
+  'deezerId': instance.deezerId,
   'availability': instance.availability,
 };
 
@@ -45,9 +47,12 @@ ServiceAvailability _$ServiceAvailabilityFromJson(Map<String, dynamic> json) =>
       tidal: json['tidal'] as bool? ?? false,
       qobuz: json['qobuz'] as bool? ?? false,
       amazon: json['amazon'] as bool? ?? false,
+      deezer: json['deezer'] as bool? ?? false,
       tidalUrl: json['tidalUrl'] as String?,
       qobuzUrl: json['qobuzUrl'] as String?,
       amazonUrl: json['amazonUrl'] as String?,
+      deezerUrl: json['deezerUrl'] as String?,
+      deezerId: json['deezerId'] as String?,
     );
 
 Map<String, dynamic> _$ServiceAvailabilityToJson(
@@ -56,7 +61,10 @@ Map<String, dynamic> _$ServiceAvailabilityToJson(
   'tidal': instance.tidal,
   'qobuz': instance.qobuz,
   'amazon': instance.amazon,
+  'deezer': instance.deezer,
   'tidalUrl': instance.tidalUrl,
   'qobuzUrl': instance.qobuzUrl,
   'amazonUrl': instance.amazonUrl,
+  'deezerUrl': instance.deezerUrl,
+  'deezerId': instance.deezerId,
 };

lib/providers/settings_provider.dart

@@ -2,8 +2,12 @@ import 'dart:convert';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:spotiflac_android/models/settings.dart';
+import 'package:spotiflac_android/services/platform_bridge.dart';
+import 'package:spotiflac_android/utils/logger.dart';
 
 const _settingsKey = 'app_settings';
+const _migrationVersionKey = 'settings_migration_version';
+const _currentMigrationVersion = 1;
 
 class SettingsNotifier extends Notifier<AppSettings> {
   @override
@@ -17,6 +21,35 @@ class SettingsNotifier extends Notifier<AppSettings> {
     final json = prefs.getString(_settingsKey);
     if (json != null) {
       state = AppSettings.fromJson(jsonDecode(json));
+      
+      // Run migrations if needed
+      await _runMigrations(prefs);
+      
+      // Apply Spotify credentials to Go backend on load
+      _applySpotifyCredentials();
+      
+      // Sync logging state
+      LogBuffer.loggingEnabled = state.enableLogging;
+    }
+  }
+
+  /// Run one-time migrations for settings
+  Future<void> _runMigrations(SharedPreferences prefs) async {
+    final lastMigration = prefs.getInt(_migrationVersionKey) ?? 0;
+    
+    if (lastMigration < 1) {
+      // Migration 1: Set metadataSource to 'deezer' for existing users
+      // Only apply if user hasn't enabled custom Spotify credentials
+      // (users with custom credentials likely prefer Spotify)
+      if (!state.useCustomSpotifyCredentials) {
+        state = state.copyWith(metadataSource: 'deezer');
+        await _saveSettings();
+      }
+    }
+    
+    // Save current migration version
+    if (lastMigration < _currentMigrationVersion) {
+      await prefs.setInt(_migrationVersionKey, _currentMigrationVersion);
     }
   }
 
@@ -25,6 +58,22 @@ class SettingsNotifier extends Notifier<AppSettings> {
     await prefs.setString(_settingsKey, jsonEncode(state.toJson()));
   }
 
+  /// Apply current Spotify credentials to Go backend
+  Future<void> _applySpotifyCredentials() async {
+    // Only apply custom credentials if enabled and both fields are set
+    if (state.useCustomSpotifyCredentials && 
+        state.spotifyClientId.isNotEmpty && 
+        state.spotifyClientSecret.isNotEmpty) {
+      await PlatformBridge.setSpotifyCredentials(
+        state.spotifyClientId,
+        state.spotifyClientSecret,
+      );
+    } else {
+      // Clear to use default
+      await PlatformBridge.setSpotifyCredentials('', '');
+    }
+  }
+
   void setDefaultService(String service) {
     state = state.copyWith(defaultService: service);
     _saveSettings();
@@ -71,6 +120,84 @@ class SettingsNotifier extends Notifier<AppSettings> {
     state = state.copyWith(concurrentDownloads: clamped);
     _saveSettings();
   }
+
+  void setCheckForUpdates(bool enabled) {
+    state = state.copyWith(checkForUpdates: enabled);
+    _saveSettings();
+  }
+
+  void setUpdateChannel(String channel) {
+    state = state.copyWith(updateChannel: channel);
+    _saveSettings();
+  }
+
+  void setHasSearchedBefore() {
+    if (!state.hasSearchedBefore) {
+      state = state.copyWith(hasSearchedBefore: true);
+      _saveSettings();
+    }
+  }
+
+  void setFolderOrganization(String organization) {
+    state = state.copyWith(folderOrganization: organization);
+    _saveSettings();
+  }
+
+  void setHistoryViewMode(String mode) {
+    state = state.copyWith(historyViewMode: mode);
+    _saveSettings();
+  }
+
+  void setAskQualityBeforeDownload(bool enabled) {
+    state = state.copyWith(askQualityBeforeDownload: enabled);
+    _saveSettings();
+  }
+
+  void setSpotifyClientId(String clientId) {
+    state = state.copyWith(spotifyClientId: clientId);
+    _saveSettings();
+  }
+
+  void setSpotifyClientSecret(String clientSecret) {
+    state = state.copyWith(spotifyClientSecret: clientSecret);
+    _saveSettings();
+  }
+
+  void setSpotifyCredentials(String clientId, String clientSecret) {
+    state = state.copyWith(
+      spotifyClientId: clientId,
+      spotifyClientSecret: clientSecret,
+    );
+    _saveSettings();
+    _applySpotifyCredentials();
+  }
+
+  void clearSpotifyCredentials() {
+    state = state.copyWith(
+      spotifyClientId: '',
+      spotifyClientSecret: '',
+    );
+    _saveSettings();
+    _applySpotifyCredentials();
+  }
+
+  void setUseCustomSpotifyCredentials(bool enabled) {
+    state = state.copyWith(useCustomSpotifyCredentials: enabled);
+    _saveSettings();
+    _applySpotifyCredentials();
+  }
+
+  void setMetadataSource(String source) {
+    state = state.copyWith(metadataSource: source);
+    _saveSettings();
+  }
+
+  void setEnableLogging(bool enabled) {
+    state = state.copyWith(enableLogging: enabled);
+    _saveSettings();
+    // Sync logging state to LogBuffer
+    LogBuffer.loggingEnabled = enabled;
+  }
 }
 
 final settingsProvider = NotifierProvider<SettingsNotifier, AppSettings>(