feat: export failed downloads to TXT file

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

.github/FUNDING.yml

@@ -0,0 +1,4 @@
+github: zarzet
+ko_fi: zarzet
+buy_me_a_coffee: zarzet
+

.github/workflows/release.yml

@@ -71,7 +71,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: "1.21"
+          go-version: "1.25"
           cache-dependency-path: go_backend/go.sum
 
       # Cache Gradle for faster builds
@@ -174,7 +174,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: "1.21"
+          go-version: "1.25"
           cache-dependency-path: go_backend/go.sum
 
       # Cache CocoaPods
@@ -194,7 +194,7 @@ jobs:
         working-directory: go_backend
         run: |
           mkdir -p ../ios/Frameworks
-          gomobile bind -target=ios -o ../ios/Frameworks/Gobackend.xcframework .
+          gomobile bind -target=ios -tags ios -o ../ios/Frameworks/Gobackend.xcframework .
         env:
           CGO_ENABLED: 1
 
@@ -249,23 +249,6 @@ jobs:
           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
 
@@ -412,3 +395,135 @@ jobs:
           prerelease: ${{ needs.get-version.outputs.is_prerelease == 'true' }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  notify-telegram:
+    runs-on: ubuntu-latest
+    needs: [get-version, create-release]
+    if: ${{ needs.get-version.outputs.is_prerelease != 'true' }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download Android APK
+        uses: actions/download-artifact@v4
+        with:
+          name: android-apk
+          path: ./release
+
+      - name: Download iOS IPA
+        uses: actions/download-artifact@v4
+        with:
+          name: ios-ipa
+          path: ./release
+
+      - name: Extract changelog for version
+        id: changelog
+        run: |
+          VERSION=${{ needs.get-version.outputs.version }}
+          VERSION_NUM=${VERSION#v}
+
+          # Extract changelog, limit to ~2500 chars for Telegram (4096 limit minus message overhead)
+          # Use tr -d '\r' to handle CRLF line endings from Windows
+          FULL_CHANGELOG=$(cat CHANGELOG.md | tr -d '\r' | sed -n "/^## \[$VERSION_NUM\]/,/^## \[/{ /^## \[$VERSION_NUM\]/d; /^## \[/d; p; }" | sed '/^---$/d')
+          
+          echo "DEBUG: Extracted changelog length: ${#FULL_CHANGELOG}"
+          echo "DEBUG: First 200 chars: ${FULL_CHANGELOG:0:200}"
+          
+          if [ -z "$FULL_CHANGELOG" ]; then
+            CHANGELOG="See release notes on GitHub for details."
+          else
+            # Convert GitHub Markdown to Telegram HTML:
+            # - **text** → <b>text</b>
+            # - `code` → <code>code</code>
+            # - ### Header → <b>Header</b>
+            # - Escape HTML special chars first
+            # - Remove > blockquote prefix
+            CHANGELOG=$(echo "$FULL_CHANGELOG" | \
+              sed 's/^> //' | \
+              sed 's/&/\&amp;/g' | \
+              sed 's/</\&lt;/g' | \
+              sed 's/>/\&gt;/g' | \
+              sed 's/`\([^`]*\)`/<code>\1<\/code>/g' | \
+              sed 's/\*\*\([^*]*\)\*\*/<b>\1<\/b>/g' | \
+              sed 's/^### \(.*\)$/<b>\1<\/b>/g' | \
+              sed 's/^## \(.*\)$/<b>\1<\/b>/g' | \
+              sed 's/^- /• /g' | \
+              sed 's/^  - /  ◦ /g')
+            
+            # Take first 2500 characters, then cut at last complete line
+            CHANGELOG=$(echo "$CHANGELOG" | head -c 2500 | sed '$d')
+            
+            # Check if truncated
+            FULL_LEN=${#FULL_CHANGELOG}
+            if [ $FULL_LEN -gt 2500 ]; then
+              CHANGELOG="${CHANGELOG}"$'\n\n... (see full changelog on GitHub)'
+            fi
+          fi
+
+          echo "$CHANGELOG" > /tmp/changelog.txt
+          echo "DEBUG: Final changelog:"
+          cat /tmp/changelog.txt
+
+      - name: Send to Telegram Channel
+        env:
+          TELEGRAM_BOT_TOKEN: ${{ secrets.TELEGRAM_BOT_TOKEN }}
+          TELEGRAM_CHANNEL_ID: ${{ secrets.TELEGRAM_CHANNEL_ID }}
+        run: |
+          VERSION=${{ needs.get-version.outputs.version }}
+          CHANGELOG=$(cat /tmp/changelog.txt)
+          
+          # Find APK files
+          ARM64_APK=$(find ./release -name "*arm64*.apk" | head -1)
+          ARM32_APK=$(find ./release -name "*arm32*.apk" | head -1)
+          
+          # Prepare message with changelog (HTML format)
+          printf '%s\n' \
+            "<b>SpotiFLAC Mobile ${VERSION} Released!</b>" \
+            "" \
+            "<b>What's New:</b>" \
+            "${CHANGELOG}" \
+            "" \
+            "<a href=\"https://github.com/${{ github.repository }}/releases/tag/${VERSION}\">View Release Notes</a>" \
+            > /tmp/telegram_message.txt
+
+          MESSAGE=$(cat /tmp/telegram_message.txt)
+
+          # Send message first (using HTML parse mode)
+          # Use --data-urlencode for proper encoding of special chars (+, &, etc.)
+          # Use || true to ensure file uploads continue even if message fails
+          curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
+            --data-urlencode "chat_id=${TELEGRAM_CHANNEL_ID}" \
+            --data-urlencode "text=${MESSAGE}" \
+            --data-urlencode "parse_mode=HTML" \
+            --data-urlencode "disable_web_page_preview=true" || true
+
+          # Upload arm64 APK to channel
+          if [ -f "$ARM64_APK" ]; then
+            echo "Uploading arm64 APK to Telegram..."
+            curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendDocument" \
+              -F chat_id="${TELEGRAM_CHANNEL_ID}" \
+              -F document=@"${ARM64_APK}" \
+              -F caption="SpotiFLAC ${VERSION} - arm64 (recommended)"
+          fi
+
+          # Upload arm32 APK to channel
+          if [ -f "$ARM32_APK" ]; then
+            echo "Uploading arm32 APK to Telegram..."
+            curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendDocument" \
+              -F chat_id="${TELEGRAM_CHANNEL_ID}" \
+              -F document=@"${ARM32_APK}" \
+              -F caption="SpotiFLAC ${VERSION} - arm32"
+          fi
+
+          # Upload iOS IPA to channel
+          IOS_IPA=$(find ./release -name "*ios*.ipa" | head -1)
+          if [ -f "$IOS_IPA" ]; then
+            echo "Uploading iOS IPA to Telegram..."
+            curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendDocument" \
+              -F chat_id="${TELEGRAM_CHANNEL_ID}" \
+              -F document=@"${IOS_IPA}" \
+              -F caption="SpotiFLAC ${VERSION} - iOS (unsigned, sideload required)"
+          fi
+
+          echo "Telegram notification sent!"

.gitignore

@@ -6,6 +6,8 @@ Thumbs.db
 .idea/
 .vscode/
 *.iml
+.cursorignore
+.cursorrules
 
 # Kiro specs (development only)
 .kiro/
@@ -59,3 +61,15 @@ extension/
 
 # Agent instructions
 AGENTS.md
+
+# Temp/misc
+nul
+
+# Log files
+*.log
+hs_err_*.log
+flutter_*.log
+
+# Development tools
+tool/
+.claude/settings.local.json

CODE_OF_CONDUCT.md

@@ -0,0 +1,133 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, caste, color, religion, or sexual
+identity and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the overall
+  community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or advances of
+  any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email address,
+  without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official email address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+**[zarzet](https://github.com/zarzet)**.
+
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series of
+actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or permanent
+ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior, harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within the
+community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.1, available at
+[https://www.contributor-covenant.org/version/2/1/code_of_conduct.html][v2.1].
+
+Community Impact Guidelines were inspired by
+[Mozilla's code of conduct enforcement ladder][Mozilla CoC].
+
+For answers to common questions about this code of conduct, see the FAQ at
+[https://www.contributor-covenant.org/faq][FAQ]. Translations are available at
+[https://www.contributor-covenant.org/translations][translations].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.1]: https://www.contributor-covenant.org/version/2/1/code_of_conduct.html
+[Mozilla CoC]: https://github.com/mozilla/diversity
+[FAQ]: https://www.contributor-covenant.org/faq
+[translations]: https://www.contributor-covenant.org/translations

CONTRIBUTING.md

@@ -0,0 +1,268 @@
+# Contributing to SpotiFLAC
+
+First off, thank you for considering contributing to SpotiFLAC! 🎉
+
+This document provides guidelines and steps for contributing. Following these guidelines helps maintain code quality and ensures a smooth collaboration process.
+
+## Table of Contents
+
+- [Code of Conduct](#code-of-conduct)
+- [How Can I Contribute?](#how-can-i-contribute)
+  - [Reporting Bugs](#reporting-bugs)
+  - [Suggesting Features](#suggesting-features)
+  - [Code Contributions](#code-contributions)
+  - [Translations](#translations)
+- [Development Setup](#development-setup)
+- [Project Structure](#project-structure)
+- [Coding Guidelines](#coding-guidelines)
+- [Commit Guidelines](#commit-guidelines)
+- [Pull Request Process](#pull-request-process)
+
+## Code of Conduct
+
+This project and everyone participating in it is governed by our [Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code. Please report unacceptable behavior to the project maintainers.
+
+## How Can I Contribute?
+
+### Reporting Bugs
+
+Before creating bug reports, please check the [existing issues](https://github.com/zarzet/SpotiFLAC-Mobile/issues) to avoid duplicates.
+
+When creating a bug report, please use the bug report template and include:
+
+- **Clear and descriptive title**
+- **Steps to reproduce** the issue
+- **Expected behavior** vs **actual behavior**
+- **Screenshots or screen recordings** if applicable
+- **Device information** (model, OS version)
+- **App version**
+- **Logs** from Settings > About > View Logs
+
+### Suggesting Features
+
+Feature requests are welcome! Please use the feature request template and:
+
+- **Check existing issues** to avoid duplicates
+- **Describe the feature** clearly
+- **Explain the use case** - why would this be useful?
+- **Consider the scope** - is this a small enhancement or a major feature?
+
+### Code Contributions
+
+1. **Fork the repository** and create your branch from `dev`
+2. **Make your changes** following our coding guidelines
+3. **Test your changes** thoroughly
+4. **Submit a pull request** to the `dev` branch
+
+### Translations
+
+We use [Crowdin](https://crowdin.com/project/spotiflac-mobile) for translations. To contribute:
+
+1. Visit our [Crowdin project](https://crowdin.com/project/spotiflac-mobile)
+2. Select your language or request a new one
+3. Start translating!
+
+Translation files are located in `lib/l10n/arb/`.
+
+## Development Setup
+
+### Prerequisites
+
+- **Flutter SDK** 3.10.0 or higher
+- **Dart SDK** 3.10.0 or higher
+- **Android Studio** or **VS Code** with Flutter extensions
+- **Git**
+
+### Getting Started
+
+1. **Clone your fork**
+   ```bash
+   git clone https://github.com/YOUR_USERNAME/SpotiFLAC-Mobile.git
+   cd SpotiFLAC-Mobile
+   ```
+
+2. **Add upstream remote**
+   ```bash
+   git remote add upstream https://github.com/zarzet/SpotiFLAC-Mobile.git
+   ```
+
+3. **Install dependencies**
+   ```bash
+   flutter pub get
+   ```
+
+4. **Generate code** (for Riverpod, JSON serialization, etc.)
+   ```bash
+   dart run build_runner build --delete-conflicting-outputs
+   ```
+
+5. **Run the app**
+   ```bash
+   flutter run
+   ```
+
+### Building
+
+```bash
+# Debug build
+flutter build apk --debug
+
+# Release build
+flutter build apk --release
+```
+
+## Project Structure
+
+```
+lib/
+├── l10n/               # Localization files
+│   └── arb/            # ARB translation files
+├── models/             # Data models
+├── providers/          # Riverpod providers
+├── screens/            # UI screens
+│   └── settings/       # Settings sub-screens
+├── services/           # Business logic services
+├── theme/              # App theming
+├── utils/              # Utility functions
+├── widgets/            # Reusable widgets
+├── app.dart            # App configuration
+└── main.dart           # Entry point
+```
+
+## Coding Guidelines
+
+### General
+
+- Follow [Effective Dart](https://dart.dev/effective-dart) guidelines
+- Use meaningful variable and function names
+- Keep functions small and focused
+- Add comments for complex logic
+
+### Formatting
+
+- Use `dart format` before committing
+- Maximum line length: 80 characters
+- Use trailing commas for better formatting
+
+```bash
+dart format .
+```
+
+### Linting
+
+Ensure your code passes all lints:
+
+```bash
+flutter analyze
+```
+
+### State Management
+
+We use **Riverpod** for state management. Follow these patterns:
+
+```dart
+// Use code generation with riverpod_annotation
+@riverpod
+class MyNotifier extends _$MyNotifier {
+  @override
+  MyState build() => MyState();
+  
+  // Methods to update state
+}
+```
+
+### Localization
+
+All user-facing strings should be localized:
+
+```dart
+// Good
+Text(AppLocalizations.of(context)!.downloadComplete)
+
+// Bad
+Text('Download Complete')
+```
+
+To add new strings:
+1. Add the key to `lib/l10n/arb/app_en.arb`
+2. Run `flutter gen-l10n`
+
+## Commit Guidelines
+
+We follow [Conventional Commits](https://www.conventionalcommits.org/):
+
+```
+<type>(<scope>): <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+### Types
+
+- `feat`: New feature
+- `fix`: Bug fix
+- `docs`: Documentation changes
+- `style`: Code style changes (formatting, etc.)
+- `refactor`: Code refactoring
+- `perf`: Performance improvements
+- `test`: Adding or updating tests
+- `chore`: Maintenance tasks
+
+### Examples
+
+```
+feat(download): add batch download support
+fix(ui): resolve overflow on small screens
+docs: update contributing guidelines
+chore(deps): update flutter_riverpod to 3.1.0
+```
+
+## Pull Request Process
+
+1. **Update your fork**
+   ```bash
+   git fetch upstream
+   git rebase upstream/dev
+   ```
+
+2. **Create a feature branch**
+   ```bash
+   git checkout -b feat/my-new-feature
+   ```
+
+3. **Make your changes** and commit following our guidelines
+
+4. **Push to your fork**
+   ```bash
+   git push origin feat/my-new-feature
+   ```
+
+5. **Create a Pull Request**
+   - Target the `dev` branch
+   - Fill in the PR template
+   - Link related issues
+
+6. **Address review feedback**
+   - Make requested changes
+   - Push additional commits
+   - Request re-review when ready
+
+### PR Requirements
+
+- [ ] Code follows project conventions
+- [ ] All tests pass
+- [ ] No new linting errors
+- [ ] Documentation updated (if needed)
+- [ ] Commit messages follow guidelines
+- [ ] PR description is clear and complete
+
+## Questions?
+
+If you have questions, feel free to:
+
+- Open a [Discussion](https://github.com/zarzet/SpotiFLAC-Mobile/discussions)
+- Check existing [Issues](https://github.com/zarzet/SpotiFLAC-Mobile/issues)
+
+Thank you for contributing! 💚

README.md

@@ -1,11 +1,12 @@
-[![GitHub All Releases](https://img.shields.io/github/downloads/zarzet/SpotiFLAC-Mobile/total?style=for-the-badge)](https://github.com/zarzet/SpotiFLAC-Mobile/releases)
+[![GitHub All Releases](https://img.shields.io/github/downloads/zarzet/SpotiFLAC-Mobile/total?style=for-the-badge&refresh=1)](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/)
+[![VirusTotal](https://img.shields.io/badge/VirusTotal-Safe-brightgreen?style=for-the-badge&logo=virustotal)](https://www.virustotal.com/gui/file/516142f029a4f3642a899832a6f600acf07040170a98c106cd03222cf584d9a3)
+[![Crowdin](https://img.shields.io/badge/HELP%20TRANSLATE%20ON-CROWDIN-%2321252b?style=for-the-badge&logo=crowdin)](https://crowdin.com/project/spotiflac-mobile)
 
 <div align="center">
 
 <img src="icon.png" width="128" />
 
-Get Spotify tracks in true FLAC from Tidal, Qobuz & Amazon Music — no account required.
+Download music in true lossless FLAC from Tidal, Qobuz & Amazon Music — no account required.
 
 ![Android](https://img.shields.io/badge/Android-7.0%2B-3DDC84?style=for-the-badge&logo=android&logoColor=white)
 ![iOS](https://img.shields.io/badge/iOS-14.0%2B-000000?style=for-the-badge&logo=apple&logoColor=white)
@@ -23,22 +24,14 @@ Get Spotify tracks in true FLAC from Tidal, Qobuz & Amazon Music — no account
   <img src="assets/images/4.jpg?v=2" width="200" />
 </p>
 
-## Metadata Source
+## Search Source
 
-SpotiFLAC supports two metadata sources for searching tracks:
+SpotiFLAC supports multiple search sources for finding music metadata:
 
-| Source | Pros | Cons |
+| Source | Setup |
-|--------|------|------|
+|--------|-------|
-| **Deezer** (Default) | No developer account needed, rate limit per user IP | Slightly less comprehensive catalog |
+| **Deezer** (Default) | No setup required |
-| **Spotify** | More comprehensive catalog, better search results | Requires developer API credentials to avoid rate limiting |
+| **Extensions** | Install additional search providers from the Store |
-
-### 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
 
 ## Extensions
 
@@ -57,15 +50,55 @@ Want to create your own extension? Check out the [Extension Development Guide](h
 ## Other project
 
 ### [SpotiFLAC (Desktop)](https://github.com/afkarxyz/SpotiFLAC)
-Get Spotify tracks in true FLAC from Tidal, Qobuz & Amazon Music for Windows, macOS & Linux
+Download music in true lossless FLAC from Tidal, Qobuz & Amazon Music for Windows, macOS & Linux
+
+## Telegram
+
+<p align="center">
+  <a href="https://t.me/spotiflac">
+    <img src="https://img.shields.io/badge/Telegram-Channel-2CA5E0?style=for-the-badge&logo=telegram&logoColor=white" alt="Telegram Channel">
+  </a>
+
+  <a href="https://t.me/spotiflac_chat">
+    <img src="https://img.shields.io/badge/Telegram-Community-2CA5E0?style=for-the-badge&logo=telegram&logoColor=white" alt="Telegram Community">
+  </a>
+</p>
+
+## FAQ
+
+**Q: Why is my download failing with "Song not found"?**  
+A: The track may not be available on Tidal, Qobuz, or Amazon Music. Try enabling more download services in Settings > Download > Provider Priority, or install additional extensions from the Store.
+
+**Q: Why are some tracks downloading in lower quality?**  
+A: Quality depends on what's available from the streaming service. Tidal offers up to 24-bit/192kHz, Qobuz up to 24-bit/192kHz, and Amazon up to 24-bit/48kHz. The app automatically selects the best available quality.
+
+**Q: Can I download playlists?**  
+A: Yes! Just paste the playlist URL in the search bar. The app will fetch all tracks and queue them for download.
+
+**Q: Why do I need to grant storage permission?**  
+A: The app needs permission to save downloaded files to your device. On Android 13+, you may need to grant "All files access" in Settings > Apps > SpotiFLAC > Permissions.
+
+**Q: Is this app safe?**  
+A: Yes, the app is open source and you can verify the code yourself. Each release is scanned with VirusTotal (see badge at top of README).
+
+**Q: Why is download not working in my country?**  
+A: Some countries have restricted access to certain streaming service APIs. If downloads are failing, try using a VPN to connect through a different region.
+
+
+### Want to support SpotiFLAC-Mobile?
+
+_If this software is useful and brings you value, consider supporting the project by buying me a coffee. Your support helps keep development going._
+
+[![Ko-fi](https://ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/zarzet) <a href="https://www.buymeacoffee.com/zarzet" target="_blank"><img src="https://cdn.buymeacoffee.com/buttons/v2/default-yellow.png" alt="Buy Me A Coffee" style="height: 40px !important;width: 150px !important;" ></a>
 
-[![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
 
 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.
+**SpotiFLAC** is a third-party tool and is not affiliated with, endorsed by, or connected to Tidal, Qobuz, Amazon Music, Deezer, or any other streaming service.
+
+The application is purely a user interface that facilitates communication between your device and existing third-party services.
 
 You are solely responsible for:
 1. Ensuring your use of this software complies with your local laws.
@@ -73,3 +106,8 @@ You are solely responsible for:
 3. Any legal consequences resulting from the misuse of this tool.
 
 The software is provided "as is", without warranty of any kind. The author assumes no liability for any bans, damages, or legal issues arising from its use.
+
+
+> [!TIP]
+>
+> **Star Us**, You will receive all release notifications from GitHub without any delay ~

android/app/proguard-rules.pro

@@ -5,6 +5,7 @@
 -keep class io.flutter.view.** { *; }
 -keep class io.flutter.** { *; }
 -keep class io.flutter.plugins.** { *; }
+-keep class io.flutter.embedding.** { *; }
 
 # Ignore missing Play Core classes (not used, but referenced by Flutter)
 -dontwarn com.google.android.play.core.splitcompat.**
@@ -14,13 +15,22 @@
 # Ignore missing javax.xml.stream (not used on Android)
 -dontwarn javax.xml.stream.**
 
-# Go backend (gobackend.aar)
+# Go backend (gobackend.aar) - CRITICAL for release builds
 -keep class gobackend.** { *; }
 -keep class go.** { *; }
+-keep interface gobackend.** { *; }
+-keepclassmembers class gobackend.** { *; }
+
+# Go mobile binding internals
+-keep class org.golang.** { *; }
+-dontwarn org.golang.**
 
 # FFmpeg Kit
 -keep class com.arthenica.ffmpegkit.** { *; }
 -keep class com.arthenica.smartexception.** { *; }
+# FFmpeg Kit (new fork package)
+-keep class com.antonkarpenko.ffmpegkit.** { *; }
+-keep class com.antonkarpenko.smartexception.** { *; }
 
 # Apache Tika (if used by FFmpeg)
 -dontwarn org.apache.tika.**
@@ -30,15 +40,77 @@
     native <methods>;
 }
 
-# Kotlin coroutines
+# Kotlin coroutines - expanded rules
 -keepnames class kotlinx.coroutines.internal.MainDispatcherFactory {}
 -keepnames class kotlinx.coroutines.CoroutineExceptionHandler {}
 -keepclassmembers class kotlinx.coroutines.** {
     volatile <fields>;
 }
+-keepclassmembernames class kotlinx.** {
+    volatile <fields>;
+}
+-dontwarn kotlinx.coroutines.**
+
+# Kotlin serialization
+-keepattributes RuntimeVisibleAnnotations,AnnotationDefault
+-dontwarn kotlin.**
+-keep class kotlin.** { *; }
+-keep class kotlin.Metadata { *; }
+
+# Keep MainActivity and related classes
+-keep class com.zarz.spotiflac.** { *; }
 
 # Prevent R8 from removing metadata
 -keepattributes *Annotation*
 -keepattributes SourceFile,LineNumberTable
 -keepattributes Signature
 -keepattributes Exceptions
+-keepattributes InnerClasses
+-keepattributes EnclosingMethod
+
+# JSON parsing (used by Go backend responses)
+-keep class org.json.** { *; }
+
+# Shared Preferences
+-keep class androidx.datastore.** { *; }
+-dontwarn androidx.datastore.**
+
+# Flutter Plugins - CRITICAL: Prevent R8 from removing plugin implementations
+# Path Provider
+-keep class io.flutter.plugins.pathprovider.** { *; }
+-keep class dev.flutter.pigeon.** { *; }
+
+# Local Notifications
+-keep class com.dexterous.** { *; }
+-keep class com.dexterous.flutterlocalnotifications.** { *; }
+
+# Receive Sharing Intent
+-keep class com.kasem.receive_sharing_intent.** { *; }
+
+# Permission Handler
+-keep class com.baseflow.permissionhandler.** { *; }
+
+# File Picker
+-keep class com.mr.flutter.plugin.filepicker.** { *; }
+
+# URL Launcher
+-keep class io.flutter.plugins.urllauncher.** { *; }
+
+# Share Plus
+-keep class dev.fluttercommunity.plus.share.** { *; }
+
+# Device Info Plus
+-keep class dev.fluttercommunity.plus.device_info.** { *; }
+
+# Open File
+-keep class com.crazecoder.openfile.** { *; }
+
+# Sqflite
+-keep class com.tekartik.sqflite.** { *; }
+
+# Dynamic Color
+-keep class io.material.** { *; }
+
+# Keep all Flutter plugin registrants
+-keep class io.flutter.plugins.GeneratedPluginRegistrant { *; }
+-keep class ** extends io.flutter.embedding.engine.plugins.FlutterPlugin { *; }

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

@@ -1,23 +1,154 @@
 package com.zarz.spotiflac
 
 import android.content.Intent
+import android.os.Build
 import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.embedding.engine.FlutterShellArgs
 import io.flutter.plugin.common.MethodChannel
 import gobackend.Gobackend
-import com.arthenica.ffmpegkit.FFmpegKit
-import com.arthenica.ffmpegkit.ReturnCode
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import java.util.Locale
 
 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)
 
+    companion object {
+        // Minimum API level we consider "safe" for Impeller (Android 10+)
+        private const val SAFE_API_FOR_IMPELLER = 29
+        
+        // Known problematic GPU patterns (lowercase)
+        private val PROBLEMATIC_GPU_PATTERNS = listOf(
+            "adreno (tm) 3",   // Adreno 300 series (305, 320, 330, etc.) - old Qualcomm
+            "adreno (tm) 4",   // Adreno 400 series - some have issues
+            "mali-4",          // Mali-400 series - old ARM GPUs
+            "mali-t6",         // Mali-T600 series
+            "mali-t7",         // Mali-T700 series (some)
+            "powervr sgx",     // PowerVR SGX series - old Imagination GPUs
+            "powervr ge8320",  // PowerVR GE8320 - known issues
+            "gc1000",          // Vivante GC1000
+            "gc2000",          // Vivante GC2000
+        )
+        
+        // Known problematic chipsets/hardware (lowercase)
+        private val PROBLEMATIC_CHIPSETS = listOf(
+            "mt6762",   // MediaTek Helio P22 with PowerVR GE8320
+            "mt6765",   // MediaTek Helio P35 with PowerVR GE8320
+            "mt8768",   // MediaTek tablet chip
+            "mp0873",   // MediaTek variant
+            "msm8974",  // Snapdragon 800/801 with Adreno 330
+            "msm8226",  // Snapdragon 400 with Adreno 305
+            "msm8926",  // Snapdragon 400 with Adreno 305
+            "apq8084",  // Snapdragon 805 (some issues)
+        )
+        
+        // Known problematic device models (lowercase)
+        private val PROBLEMATIC_MODELS = listOf(
+            "sm-t220",      // Samsung Tab A7 Lite
+            "sm-t225",      // Samsung Tab A7 Lite LTE
+            "hammerhead",   // Nexus 5 (Adreno 330)
+        )
+    }
+
+    /**
+     * Override Flutter shell args to disable Impeller on problematic devices.
+     * This is called before the Flutter engine starts.
+     */
+    override fun getFlutterShellArgs(): FlutterShellArgs {
+        val args = super.getFlutterShellArgs()
+        
+        if (shouldDisableImpeller()) {
+            // Log for debugging
+            android.util.Log.i("SpotiFLAC", "Legacy/problematic GPU detected: Disabling Impeller for ${Build.MODEL}")
+            android.util.Log.i("SpotiFLAC", "Device: ${Build.MANUFACTURER} ${Build.MODEL}, SDK: ${Build.VERSION.SDK_INT}")
+            android.util.Log.i("SpotiFLAC", "Hardware: ${Build.HARDWARE}, Board: ${Build.BOARD}")
+            
+            // Disable Impeller, forcing Skia renderer
+            args.add("--enable-impeller=false")
+        } else {
+            android.util.Log.i("SpotiFLAC", "Using Impeller renderer for ${Build.MODEL}")
+        }
+        
+        return args
+    }
+
+    /**
+     * Check if device should use Skia instead of Impeller.
+     * Returns true for devices with old/problematic GPUs or old Android versions.
+     */
+    private fun shouldDisableImpeller(): Boolean {
+        val hardware = Build.HARDWARE.lowercase(Locale.ROOT)
+        val board = Build.BOARD.lowercase(Locale.ROOT)
+        val model = Build.MODEL.lowercase(Locale.ROOT)
+        val device = Build.DEVICE.lowercase(Locale.ROOT)
+        
+        // 1. Check for explicitly problematic device models
+        for (problematicModel in PROBLEMATIC_MODELS) {
+            if (model.contains(problematicModel) || device.contains(problematicModel)) {
+                android.util.Log.i("SpotiFLAC", "Matched problematic model: $problematicModel")
+                return true
+            }
+        }
+        
+        // 2. Check for problematic chipsets
+        for (chipset in PROBLEMATIC_CHIPSETS) {
+            if (hardware.contains(chipset) || board.contains(chipset)) {
+                android.util.Log.i("SpotiFLAC", "Matched problematic chipset: $chipset")
+                return true
+            }
+        }
+        
+        // 3. For Android < 10 (API 29), be more aggressive about disabling Impeller
+        if (Build.VERSION.SDK_INT < SAFE_API_FOR_IMPELLER) {
+            // For older Android, check GPU renderer if available
+            val gpuRenderer = getGpuRenderer().lowercase(Locale.ROOT)
+            
+            // Check for known problematic GPUs
+            for (pattern in PROBLEMATIC_GPU_PATTERNS) {
+                if (gpuRenderer.contains(pattern)) {
+                    android.util.Log.i("SpotiFLAC", "Matched problematic GPU on old Android: $pattern")
+                    return true
+                }
+            }
+            
+            // For very old Android (< 8.0), always use Skia as Vulkan support is spotty
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+                android.util.Log.i("SpotiFLAC", "Android < 8.0, using Skia for safety")
+                return true
+            }
+        }
+        
+        // 4. For Android 10+, still check for known problematic GPUs
+        val gpuRenderer = getGpuRenderer().lowercase(Locale.ROOT)
+        for (pattern in PROBLEMATIC_GPU_PATTERNS) {
+            if (gpuRenderer.contains(pattern)) {
+                android.util.Log.i("SpotiFLAC", "Matched problematic GPU: $pattern")
+                return true
+            }
+        }
+        
+        return false
+    }
+    
+    /**
+     * Try to get GPU renderer string.
+     * Note: This may return empty on some devices before OpenGL context is created.
+     */
+    private fun getGpuRenderer(): String {
+        return try {
+            // This might not work before GL context is created,
+            // but worth trying for additional detection
+            android.opengl.GLES20.glGetString(android.opengl.GLES20.GL_RENDERER) ?: ""
+        } catch (e: Exception) {
+            ""
+        }
+    }
+
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
         // Update the intent so receive_sharing_intent can access the new data
@@ -117,6 +248,13 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(null)
                         }
+                        "cancelDownload" -> {
+                            val itemId = call.argument<String>("item_id") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.cancelDownload(itemId)
+                            }
+                            result.success(null)
+                        }
                         "setDownloadDirectory" -> {
                             val path = call.argument<String>("path") ?: ""
                             withContext(Dispatchers.IO) {
@@ -132,6 +270,28 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "checkDuplicatesBatch" -> {
+                            val outputDir = call.argument<String>("output_dir") ?: ""
+                            val tracksJson = call.argument<String>("tracks") ?: "[]"
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.checkDuplicatesBatch(outputDir, tracksJson)
+                            }
+                            result.success(response)
+                        }
+                        "preBuildDuplicateIndex" -> {
+                            val outputDir = call.argument<String>("output_dir") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.preBuildDuplicateIndex(outputDir)
+                            }
+                            result.success(null)
+                        }
+                        "invalidateDuplicateIndex" -> {
+                            val outputDir = call.argument<String>("output_dir") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.invalidateDuplicateIndex(outputDir)
+                            }
+                            result.success(null)
+                        }
                         "buildFilename" -> {
                             val template = call.argument<String>("template") ?: ""
                             val metadata = call.argument<String>("metadata") ?: "{}"
@@ -151,8 +311,9 @@ 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 durationMs = call.argument<Int>("duration_ms")?.toLong() ?: 0L
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.fetchLyrics(spotifyId, trackName, artistName)
+                                Gobackend.fetchLyrics(spotifyId, trackName, artistName, durationMs)
                             }
                             result.success(response)
                         }
@@ -161,8 +322,9 @@ class MainActivity: FlutterActivity() {
                             val trackName = call.argument<String>("track_name") ?: ""
                             val artistName = call.argument<String>("artist_name") ?: ""
                             val filePath = call.argument<String>("file_path") ?: ""
+                            val durationMs = call.argument<Int>("duration_ms")?.toLong() ?: 0L
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.getLyricsLRC(spotifyId, trackName, artistName, filePath)
+                                Gobackend.getLyricsLRC(spotifyId, trackName, artistName, filePath, durationMs)
                             }
                             result.success(response)
                         }
@@ -247,9 +409,10 @@ class MainActivity: FlutterActivity() {
                         "searchDeezerAll" -> {
                             val query = call.argument<String>("query") ?: ""
                             val trackLimit = call.argument<Int>("track_limit") ?: 15
-                            val artistLimit = call.argument<Int>("artist_limit") ?: 3
+                            val artistLimit = call.argument<Int>("artist_limit") ?: 2
+                            val filter = call.argument<String>("filter") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.searchDeezerAll(query, trackLimit.toLong(), artistLimit.toLong())
+                                Gobackend.searchDeezerAll(query, trackLimit.toLong(), artistLimit.toLong(), filter)
                             }
                             result.success(response)
                         }
@@ -275,6 +438,13 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "getDeezerExtendedMetadata" -> {
+                            val trackId = call.argument<String>("track_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getDeezerExtendedMetadata(trackId)
+                            }
+                            result.success(response)
+                        }
                         "convertSpotifyToDeezer" -> {
                             val resourceType = call.argument<String>("resource_type") ?: ""
                             val spotifyId = call.argument<String>("spotify_id") ?: ""
@@ -290,6 +460,43 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "checkAvailabilityFromDeezerID" -> {
+                            val deezerTrackId = call.argument<String>("deezer_track_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.checkAvailabilityFromDeezerID(deezerTrackId)
+                            }
+                            result.success(response)
+                        }
+                        "checkAvailabilityByPlatformID" -> {
+                            val platform = call.argument<String>("platform") ?: ""
+                            val entityType = call.argument<String>("entity_type") ?: ""
+                            val entityId = call.argument<String>("entity_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.checkAvailabilityByPlatformID(platform, entityType, entityId)
+                            }
+                            result.success(response)
+                        }
+                        "getSpotifyIDFromDeezerTrack" -> {
+                            val deezerTrackId = call.argument<String>("deezer_track_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getSpotifyIDFromDeezerTrack(deezerTrackId)
+                            }
+                            result.success(response)
+                        }
+                        "getTidalURLFromDeezerTrack" -> {
+                            val deezerTrackId = call.argument<String>("deezer_track_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getTidalURLFromDeezerTrack(deezerTrackId)
+                            }
+                            result.success(response)
+                        }
+                        "getAmazonURLFromDeezerTrack" -> {
+                            val deezerTrackId = call.argument<String>("deezer_track_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getAmazonURLFromDeezerTrack(deezerTrackId)
+                            }
+                            result.success(response)
+                        }
                         // Log methods
                         "getLogs" -> {
                             val response = withContext(Dispatchers.IO) {
@@ -429,6 +636,14 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(null)
                         }
+                        "invokeExtensionAction" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val actionName = call.argument<String>("action") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.invokeExtensionActionJSON(extensionId, actionName)
+                            }
+                            result.success(response)
+                        }
                         "searchTracksWithExtensions" -> {
                             val query = call.argument<String>("query") ?: ""
                             val limit = call.argument<Int>("limit") ?: 20
@@ -444,6 +659,14 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "enrichTrackWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val trackJson = call.argument<String>("track") ?: "{}"
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.enrichTrackWithExtensionJSON(extensionId, trackJson)
+                            }
+                            result.success(response)
+                        }
                         "removeExtension" -> {
                             val extensionId = call.argument<String>("extension_id") ?: ""
                             withContext(Dispatchers.IO) {
@@ -572,6 +795,30 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(response)
                         }
+                        "getAlbumWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val albumId = call.argument<String>("album_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getAlbumWithExtensionJSON(extensionId, albumId)
+                            }
+                            result.success(response)
+                        }
+                        "getPlaylistWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val playlistId = call.argument<String>("playlist_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getPlaylistWithExtensionJSON(extensionId, playlistId)
+                            }
+                            result.success(response)
+                        }
+                        "getArtistWithExtension" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val artistId = call.argument<String>("artist_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getArtistWithExtensionJSON(extensionId, artistId)
+                            }
+                            result.success(response)
+                        }
                         // Extension Post-Processing API
                         "runPostProcessing" -> {
                             val filePath = call.argument<String>("file_path") ?: ""
@@ -630,6 +877,21 @@ class MainActivity: FlutterActivity() {
                             }
                             result.success(null)
                         }
+                        // Extension Home Feed (Explore)
+                        "getExtensionHomeFeed" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getExtensionHomeFeedJSON(extensionId)
+                            }
+                            result.success(response)
+                        }
+                        "getExtensionBrowseCategories" -> {
+                            val extensionId = call.argument<String>("extension_id") ?: ""
+                            val response = withContext(Dispatchers.IO) {
+                                Gobackend.getExtensionBrowseCategoriesJSON(extensionId)
+                            }
+                            result.success(response)
+                        }
                         else -> result.notImplemented()
                     }
                 } catch (e: Exception) {
@@ -637,37 +899,5 @@ 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)
-                }
-            }
-        }
     }
 }

build_assets/ffmpeg_service_ios.dart

@@ -1,208 +0,0 @@
-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});
-}

crowdin.yml

@@ -0,0 +1,19 @@
+files:
+  - source: /lib/l10n/arb/app_en.arb
+    translation: /lib/l10n/arb/app_%locale%.arb
+    languages_mapping:
+      locale:
+        # Short codes for single-variant languages
+        de: de
+        es: es
+        fr: fr
+        hi: hi
+        id: id
+        ja: ja
+        ko: ko
+        nl: nl
+        pt: pt
+        ru: ru
+        # Full codes for Chinese variants
+        zh-CN: zh_CN
+        zh-TW: zh_TW

go_backend/amazon.go

@@ -2,100 +2,40 @@ package gobackend
 
 import (
 	"bufio"
-	"encoding/base64"
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
 	"net/url"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
 )
 
-// AmazonDownloader handles Amazon Music downloads using DoubleDouble service (same as PC)
 type AmazonDownloader struct {
-	client           *http.Client
+	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
+// AfkarXYZResponse is the response from AfkarXYZ API
-type DoubleDoubleSubmitResponse struct {
+type AfkarXYZResponse struct {
-	Success bool   `json:"success"`
+	Success bool `json:"success"`
-	ID      string `json:"id"`
+	Data    struct {
+		DirectLink string `json:"direct_link"`
+		FileName   string `json:"file_name"`
+		FileSize   int64  `json:"file_size"`
+	} `json:"data"`
 }
 
-// DoubleDoubleStatusResponse is the response from DoubleDouble status endpoint
-type DoubleDoubleStatusResponse struct {
-	Status         string `json:"status"`
-	FriendlyStatus string `json:"friendlyStatus"`
-	URL            string `json:"url"`
-	Current        struct {
-		Name   string `json:"name"`
-		Artist string `json:"artist"`
-	} `json:"current"`
-}
-
-// 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 {
@@ -105,254 +45,79 @@ func amazonIsASCIIString(s string) bool {
 	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
+			client: NewHTTPClientWithTimeout(120 * time.Second),
-			regions:          []string{"us", "eu"},                        // Same regions as PC
-			apiCallResetTime: time.Now(),
 		}
 	})
 	return globalAmazonDownloader
 }
 
-// waitForRateLimit implements rate limiting similar to PC version
+func (a *AmazonDownloader) downloadFromAfkarXYZ(amazonURL string) (string, string, error) {
-// Max 9 requests per minute with 7 second delay between requests
+	apiURL := "https://amazon.afkarxyz.fun/convert?url=" + url.QueryEscape(amazonURL)
-func (a *AmazonDownloader) waitForRateLimit() {
-	amazonRateLimitMu.Lock()
-	defer amazonRateLimitMu.Unlock()
 
-	now := time.Now()
+	GoLog("[Amazon] Fetching from AfkarXYZ API...\n")
 
-	// Reset counter every minute
+	req, err := http.NewRequest("GET", apiURL, nil)
-	if now.Sub(a.apiCallResetTime) >= time.Minute {
+	if err != nil {
-		a.apiCallCount = 0
+		return "", "", fmt.Errorf("failed to create request: %w", err)
-		a.apiCallResetTime = now
 	}
 
-	// If we've hit the limit (9 requests per minute), wait until next minute
+	req.Header.Set("User-Agent", getRandomUserAgent())
-	if a.apiCallCount >= 9 {
+
-		waitTime := time.Minute - now.Sub(a.apiCallResetTime)
+	resp, err := a.client.Do(req)
-		if waitTime > 0 {
+	if err != nil {
-			GoLog("[Amazon] Rate limit reached, waiting %v...\n", waitTime.Round(time.Second))
+		return "", "", fmt.Errorf("failed to call AfkarXYZ API: %w", err)
-			time.Sleep(waitTime)
+	}
-			a.apiCallCount = 0
+	defer resp.Body.Close()
-			a.apiCallResetTime = time.Now()
+
-		}
+	if resp.StatusCode != 200 {
+		return "", "", fmt.Errorf("AfkarXYZ API returned status %d", resp.StatusCode)
 	}
 
-	// Add delay between requests (7 seconds like PC version)
+	body, err := io.ReadAll(resp.Body)
-	if !a.lastAPICallTime.IsZero() {
+	if err != nil {
-		timeSinceLastCall := now.Sub(a.lastAPICallTime)
+		return "", "", fmt.Errorf("failed to read response: %w", err)
-		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
+	var apiResp AfkarXYZResponse
-	a.lastAPICallTime = time.Now()
+	if err := json.Unmarshal(body, &apiResp); err != nil {
-	a.apiCallCount++
+		return "", "", fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	if !apiResp.Success || apiResp.Data.DirectLink == "" {
+		return "", "", fmt.Errorf("AfkarXYZ API failed or no download link found")
+	}
+
+	fileName := apiResp.Data.FileName
+	if fileName == "" {
+		fileName = "track.flac"
+	}
+
+	reg := regexp.MustCompile(`[<>:"/\\|?*]`)
+	fileName = reg.ReplaceAllString(fileName, "")
+
+	GoLog("[Amazon] AfkarXYZ returned: %s (%.2f MB)\n", fileName, float64(apiResp.Data.FileSize)/(1024*1024))
+
+	return apiResp.Data.DirectLink, fileName, nil
 }
 
-// GetAvailableAPIs returns list of available DoubleDouble regions
-// Uses same service as PC version (doubledouble.top)
-func (a *AmazonDownloader) GetAvailableAPIs() []string {
-	// DoubleDouble service regions (same as PC)
-	// Format: https://{region}.doubledouble.top
-	var apis []string
-	for _, region := range a.regions {
-		apis = append(apis, fmt.Sprintf("https://%s.doubledouble.top", region))
-	}
-	return apis
-}
-
-// downloadFromDoubleDoubleService downloads a track using DoubleDouble service (same as PC)
-// This uses submit → poll → download mechanism
-// Internal function - not exported to gomobile
-func (a *AmazonDownloader) downloadFromDoubleDoubleService(amazonURL, _ string) (string, string, string, error) {
-	var lastError error
-
-	for _, region := range a.regions {
-		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://
-		serviceDomain, _ := base64.StdEncoding.DecodeString("LmRvdWJsZWRvdWJsZS50b3A=") // .doubledouble.top
-		baseURL := fmt.Sprintf("%s%s%s", string(serviceBase), region, string(serviceDomain))
-
-		// 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)
-			continue
-		}
-
-		req.Header.Set("User-Agent", getRandomUserAgent())
-
-		fmt.Println("[Amazon] Submitting download request...")
-
-		// 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 err != nil || lastError != nil {
-			if resp != nil {
-				resp.Body.Close()
-			}
-			continue
-		}
-
-		var submitResp DoubleDoubleSubmitResponse
-		if err := json.NewDecoder(resp.Body).Decode(&submitResp); err != nil {
-			resp.Body.Close()
-			lastError = fmt.Errorf("failed to decode submit response: %w", err)
-			continue
-		}
-		resp.Body.Close()
-
-		if !submitResp.Success || submitResp.ID == "" {
-			lastError = fmt.Errorf("submit request failed")
-			continue
-		}
-
-		downloadID := submitResp.ID
-		GoLog("[Amazon] Download ID: %s\n", downloadID)
-
-		// Step 2: Poll for completion
-		statusURL := fmt.Sprintf("%s/dl/%s", baseURL, downloadID)
-		fmt.Println("[Amazon] Waiting for download to complete...")
-
-		maxWait := 300 * time.Second // 5 minutes max wait
-		elapsed := time.Duration(0)
-		pollInterval := 3 * time.Second
-
-		for elapsed < maxWait {
-			time.Sleep(pollInterval)
-			elapsed += pollInterval
-
-			statusReq, err := http.NewRequest("GET", statusURL, nil)
-			if err != nil {
-				continue
-			}
-
-			statusReq.Header.Set("User-Agent", getRandomUserAgent())
-
-			statusResp, err := a.client.Do(statusReq)
-			if err != nil {
-				fmt.Printf("\r[Amazon] Status check failed, retrying...")
-				continue
-			}
-
-			if statusResp.StatusCode != 200 {
-				statusResp.Body.Close()
-				fmt.Printf("\r[Amazon] Status check failed (status %d), retrying...", statusResp.StatusCode)
-				continue
-			}
-
-			var status DoubleDoubleStatusResponse
-			if err := json.NewDecoder(statusResp.Body).Decode(&status); err != nil {
-				statusResp.Body.Close()
-				fmt.Printf("\r[Amazon] Invalid JSON response, retrying...")
-				continue
-			}
-			statusResp.Body.Close()
-
-			if status.Status == "done" {
-				fmt.Println("\n[Amazon] Download ready!")
-
-				// Build download URL
-				fileURL := status.URL
-				if strings.HasPrefix(fileURL, "./") {
-					fileURL = fmt.Sprintf("%s/%s", baseURL, fileURL[2:])
-				} else if strings.HasPrefix(fileURL, "/") {
-					fileURL = fmt.Sprintf("%s%s", baseURL, fileURL)
-				}
-
-				trackName := status.Current.Name
-				artist := status.Current.Artist
-
-				GoLog("[Amazon] Downloading: %s - %s\n", artist, trackName)
-				return fileURL, trackName, artist, nil
-
-			} else if status.Status == "error" {
-				errorMsg := status.FriendlyStatus
-				if errorMsg == "" {
-					errorMsg = "Unknown error"
-				}
-				lastError = fmt.Errorf("processing failed: %s", errorMsg)
-				break
-			} else {
-				// Still processing
-				friendlyStatus := status.FriendlyStatus
-				if friendlyStatus == "" {
-					friendlyStatus = status.Status
-				}
-				fmt.Printf("\r[Amazon] %s...", friendlyStatus)
-			}
-		}
-
-		if elapsed >= maxWait {
-			lastError = fmt.Errorf("download timeout")
-			fmt.Printf("\n[Amazon] Error with %s region: %v\n", region, lastError)
-			continue
-		}
-
-		if lastError != nil {
-			fmt.Printf("\n[Amazon] Error with %s region: %v\n", region, lastError)
-		}
-	}
-
-	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, itemID string) error {
-	// Initialize item progress (required for all downloads)
+	ctx := context.Background()
+
 	if itemID != "" {
 		StartItemProgress(itemID)
 		defer CompleteItemProgress(itemID)
+		ctx = initDownloadCancel(itemID)
+		defer clearDownloadCancel(itemID)
 	}
 
-	req, err := http.NewRequest("GET", downloadURL, nil)
+	if isDownloadCancelled(itemID) {
+		return ErrDownloadCancelled
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
 	if err != nil {
 		return fmt.Errorf("failed to create request: %w", err)
 	}
@@ -361,6 +126,9 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 
 	resp, err := a.client.Do(req)
 	if err != nil {
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
 		return err
 	}
 	defer resp.Body.Close()
@@ -370,7 +138,6 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 	}
 
 	expectedSize := resp.ContentLength
-	// Set total bytes if available
 	if expectedSize > 0 && itemID != "" {
 		SetItemBytesTotal(itemID, expectedSize)
 	}
@@ -380,26 +147,24 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 		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 != "" {
 		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)
 	}
 
-	// Flush buffer before checking for errors
 	flushErr := bufWriter.Flush()
 	closeErr := out.Close()
 
-	// Check for any errors
 	if err != nil {
 		os.Remove(outputPath)
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
 		return fmt.Errorf("download interrupted: %w", err)
 	}
 	if flushErr != nil {
@@ -411,13 +176,12 @@ func (a *AmazonDownloader) DownloadFile(downloadURL, outputPath, itemID string)
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
-	// Verify file size if Content-Length was provided
 	if expectedSize > 0 && written != expectedSize {
 		os.Remove(outputPath)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
 	}
 
-	fmt.Printf("\r[Amazon] Downloaded: %.2f MB (Complete)\n", float64(written)/(1024*1024))
+	GoLog("[Amazon] Downloaded: %.2f MB (Complete)\n", float64(written)/(1024*1024))
 	return nil
 }
 
@@ -435,29 +199,21 @@ type AmazonDownloadResult struct {
 	ISRC        string
 }
 
-// downloadFromAmazon downloads a track using the request parameters
-// Uses DoubleDouble service (same as PC version)
 func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	downloader := NewAmazonDownloader()
 
-	// Check for existing file first
 	if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
 		return AmazonDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
-	// Get Amazon URL from SongLink
 	songlink := NewSongLinkClient()
 	var availability *TrackAvailability
 	var err error
 
-	// Check if SpotifyID is actually a Deezer ID (format: "deezer:xxxxx")
+	if deezerID, found := strings.CutPrefix(req.SpotifyID, "deezer:"); found {
-	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")
@@ -471,30 +227,21 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 		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 AmazonDownloadResult{}, fmt.Errorf("failed to create output directory: %w", err)
 		}
 	}
 
-	// Download using DoubleDouble service (same as PC)
+	// Download using AfkarXYZ API
-	downloadURL, trackName, artistName, err := downloader.downloadFromDoubleDoubleService(availability.AmazonURL, req.OutputDir)
+	downloadURL, _, err := downloader.downloadFromAfkarXYZ(availability.AmazonURL)
 	if err != nil {
-		return AmazonDownloadResult{}, fmt.Errorf("failed to get download URL: %w", err)
+		return AmazonDownloadResult{}, fmt.Errorf("failed to get download URL from AfkarXYZ: %w", err)
 	}
 
-	// Verify artist matches
+	GoLog("[Amazon] Match found: '%s' by '%s'\n", req.TrackName, req.ArtistName)
-	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
+	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]any{
-	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,
 		"artist": req.ArtistName,
 		"album":  req.AlbumName,
@@ -505,7 +252,6 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 	filename = sanitizeFilename(filename) + ".flac"
 	outputPath := filepath.Join(req.OutputDir, filename)
 
-	// Check if file already exists
 	if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
 		return AmazonDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
@@ -522,37 +268,35 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 			req.TrackName,
 			req.ArtistName,
 			req.EmbedLyrics,
+			int64(req.DurationMS),
 		)
 	}()
 
 	// Download audio file with item ID for progress tracking
 	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+		if errors.Is(err, ErrDownloadCancelled) {
+			return AmazonDownloadResult{}, ErrDownloadCancelled
+		}
 		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 != "" {
-		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
+	actualDate := req.ReleaseDate
+	actualAlbum := req.AlbumName
+	actualTitle := req.TrackName
+	actualArtist := req.ArtistName
 
 	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)
@@ -561,49 +305,80 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 			actualDiscNum = existingMeta.DiscNumber
 			GoLog("[Amazon] Using disc number from file: %d (request had: %d)\n", actualDiscNum, req.DiscNumber)
 		}
+		if existingMeta.Date != "" && req.ReleaseDate == "" {
+			actualDate = existingMeta.Date
+			GoLog("[Amazon] Using release date from file: %s\n", actualDate)
+		}
+		if existingMeta.Album != "" && req.AlbumName == "" {
+			actualAlbum = existingMeta.Album
+			GoLog("[Amazon] Using album from file: %s\n", actualAlbum)
+		}
+		GoLog("[Amazon] Existing metadata - Title: %s, Artist: %s, Album: %s, Date: %s\n",
+			existingMeta.Title, existingMeta.Artist, existingMeta.Album, existingMeta.Date)
 	}
 
-	// Embed metadata using Spotify data (more accurate than DoubleDouble)
-	// But preserve track/disc numbers from file if they were better
 	metadata := Metadata{
-		Title:       req.TrackName,
+		Title:       actualTitle,
-		Artist:      req.ArtistName,
+		Artist:      actualArtist,
-		Album:       req.AlbumName,
+		Album:       actualAlbum,
 		AlbumArtist: req.AlbumArtist,
-		Date:        req.ReleaseDate,
+		Date:        actualDate,
 		TrackNumber: actualTrackNum,
 		TotalTracks: req.TotalTracks,
 		DiscNumber:  actualDiscNum,
 		ISRC:        req.ISRC,
+		Genre:       req.Genre,
+		Label:       req.Label,
+		Copyright:   req.Copyright,
 	}
 
-	// Use cover data from parallel fetch
 	var coverData []byte
-	if parallelResult != nil && parallelResult.CoverData != nil {
+	if parallelResult != nil && parallelResult.CoverData != nil && len(parallelResult.CoverData) > 0 {
 		coverData = parallelResult.CoverData
 		GoLog("[Amazon] Using parallel-fetched cover (%d bytes)\n", len(coverData))
+	} else {
+		existingCover, coverErr := ExtractCoverArt(outputPath)
+		if coverErr == nil && len(existingCover) > 0 {
+			coverData = existingCover
+			GoLog("[Amazon] Using existing cover from Amazon file (%d bytes)\n", len(coverData))
+		} else {
+			GoLog("[Amazon] No cover available (parallel fetch failed and no existing cover)\n")
+		}
 	}
 
 	if err := EmbedMetadataWithCoverData(outputPath, metadata, coverData); err != nil {
-		fmt.Printf("Warning: failed to embed metadata: %v\n", err)
+		GoLog("[Amazon] Warning: failed to embed metadata: %v\n", err)
 	}
 
-	// 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))
+		lyricsMode := req.LyricsMode
-		if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+		if lyricsMode == "" {
-			GoLog("[Amazon] Warning: failed to embed lyrics: %v\n", embedErr)
+			lyricsMode = "embed"
-		} else {
+		}
-			fmt.Println("[Amazon] Lyrics embedded successfully")
+
+		if lyricsMode == "external" || lyricsMode == "both" {
+			GoLog("[Amazon] Saving external LRC file...\n")
+			if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
+				GoLog("[Amazon] Warning: failed to save LRC file: %v\n", lrcErr)
+			} else {
+				GoLog("[Amazon] LRC file saved: %s\n", lrcPath)
+			}
+		}
+
+		if lyricsMode == "embed" || lyricsMode == "both" {
+			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 {
+				GoLog("[Amazon] Lyrics embedded successfully\n")
+			}
 		}
 	} else if req.EmbedLyrics {
-		fmt.Println("[Amazon] No lyrics available from parallel fetch")
+		GoLog("[Amazon] No lyrics available from parallel fetch\n")
 	}
 
-	fmt.Println("[Amazon] ✓ Downloaded successfully from Amazon Music")
+	GoLog("[Amazon] Downloaded successfully from Amazon Music\n")
 
-	// 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)
@@ -611,8 +386,6 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 		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",
@@ -620,7 +393,6 @@ func downloadFromAmazon(req DownloadRequest) (AmazonDownloadResult, error) {
 		actualTrackNum = finalMeta.TrackNumber
 		actualDiscNum = finalMeta.DiscNumber
 		if finalMeta.Date != "" {
-			// Use date from file if available
 			req.ReleaseDate = finalMeta.Date
 		}
 	}

go_backend/cancel.go

@@ -0,0 +1,78 @@
+package gobackend
+
+import (
+	"context"
+	"errors"
+	"sync"
+)
+
+// ErrDownloadCancelled is returned when a download is cancelled by the user.
+var ErrDownloadCancelled = errors.New("download cancelled")
+
+type cancelEntry struct {
+	cancel   context.CancelFunc
+	canceled bool
+}
+
+var (
+	cancelMu  sync.Mutex
+	cancelMap = make(map[string]*cancelEntry)
+)
+
+func initDownloadCancel(itemID string) context.Context {
+	if itemID == "" {
+		return context.Background()
+	}
+
+	cancelMu.Lock()
+	defer cancelMu.Unlock()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancelMap[itemID] = &cancelEntry{
+		cancel:   cancel,
+		canceled: false,
+	}
+	return ctx
+}
+
+func cancelDownload(itemID string) {
+	if itemID == "" {
+		return
+	}
+
+	cancelMu.Lock()
+	entry, ok := cancelMap[itemID]
+	if ok {
+		entry.canceled = true
+		if entry.cancel != nil {
+			entry.cancel()
+		}
+	} else {
+		cancelMap[itemID] = &cancelEntry{canceled: true}
+	}
+	cancelMu.Unlock()
+
+	RemoveItemProgress(itemID)
+}
+
+func isDownloadCancelled(itemID string) bool {
+	if itemID == "" {
+		return false
+	}
+
+	cancelMu.Lock()
+	entry, ok := cancelMap[itemID]
+	canceled := ok && entry.canceled
+	cancelMu.Unlock()
+	return canceled
+}
+
+func clearDownloadCancel(itemID string) {
+	if itemID == "" {
+		return
+	}
+
+	cancelMu.Lock()
+	delete(cancelMap, itemID)
+	cancelMu.Unlock()
+}

go_backend/cover.go

@@ -4,18 +4,19 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 	"strings"
 )
 
-// Spotify image size codes (same as PC version)
 const (
-	spotifySize300 = "ab67616d00001e02" // 300x300 (small)
+	spotifySize300 = "ab67616d00001e02"
-	spotifySize640 = "ab67616d0000b273" // 640x640 (medium)
+	spotifySize640 = "ab67616d0000b273"
-	spotifySizeMax = "ab67616d000082c1" // Max resolution (~2000x2000)
+	spotifySizeMax = "ab67616d000082c1"
 )
 
-// convertSmallToMedium upgrades 300x300 cover URL to 640x640
+// Deezer CDN supports these sizes: 56, 250, 500, 1000, 1400, 1800
-// Same logic as PC version for consistency
+var deezerSizeRegex = regexp.MustCompile(`/(\d+)x(\d+)-\d+-\d+-\d+-\d+\.jpg$`)
+
 func convertSmallToMedium(imageURL string) string {
 	if strings.Contains(imageURL, spotifySize300) {
 		return strings.Replace(imageURL, spotifySize300, spotifySize640, 1)
@@ -23,8 +24,6 @@ func convertSmallToMedium(imageURL string) string {
 	return imageURL
 }
 
-// downloadCoverToMemory downloads cover art and returns as bytes (no file creation)
-// This avoids file permission issues on Android
 func downloadCoverToMemory(coverURL string, maxQuality bool) ([]byte, error) {
 	if coverURL == "" {
 		return nil, fmt.Errorf("no cover URL provided")
@@ -32,20 +31,19 @@ func downloadCoverToMemory(coverURL string, maxQuality bool) ([]byte, error) {
 
 	GoLog("[Cover] Original URL: %s", coverURL)
 
-	// First upgrade small (300) to medium (640) - always do this
 	downloadURL := convertSmallToMedium(coverURL)
 	if downloadURL != coverURL {
 		GoLog("[Cover] Upgraded 300x300 → 640x640")
 	}
 
-	// Then upgrade to max quality if requested
 	if maxQuality {
 		maxURL := upgradeToMaxQuality(downloadURL)
 		if maxURL != downloadURL {
 			downloadURL = maxURL
-			GoLog("[Cover] Upgraded to max resolution (~2000x2000)")
+			// Log already printed by upgradeToMaxQuality for Deezer
-		} else {
+			if strings.Contains(coverURL, "scdn.co") || strings.Contains(coverURL, "spotifycdn") {
-			GoLog("[Cover] Max resolution not available, using 640x640")
+				GoLog("[Cover] Spotify: upgraded to max resolution (~2000x2000)")
+			}
 		}
 	}
 
@@ -53,7 +51,6 @@ func downloadCoverToMemory(coverURL string, maxQuality bool) ([]byte, error) {
 
 	client := NewHTTPClientWithTimeout(DefaultTimeout)
 
-	// Create request with User-Agent (required by Spotify CDN)
 	req, err := http.NewRequest("GET", downloadURL, nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create request: %w", err)
@@ -74,8 +71,6 @@ func downloadCoverToMemory(coverURL string, maxQuality bool) ([]byte, error) {
 		return nil, fmt.Errorf("failed to read cover data: %w", err)
 	}
 
-	// Calculate approximate resolution from file size
-	// JPEG ~2000x2000 is typically 300-600KB, 640x640 is ~50-100KB
 	sizeKB := len(data) / 1024
 	var resolution string
 	if sizeKB > 200 {
@@ -90,23 +85,33 @@ func downloadCoverToMemory(coverURL string, maxQuality bool) ([]byte, error) {
 	return data, nil
 }
 
-// upgradeToMaxQuality upgrades Spotify cover URL to maximum quality
-// Same logic as PC version - directly replaces 640x640 size code with max resolution
-// No HEAD verification needed - Spotify CDN always serves max resolution if available
 func upgradeToMaxQuality(coverURL string) string {
-	// Spotify image URLs can be upgraded by changing the size parameter
+	// Spotify CDN upgrade
-	// Format: https://i.scdn.co/image/ab67616d0000b273...
-	// ab67616d0000b273 = 640x640
-	// ab67616d000082c1 = Max resolution (~2000x2000)
-
 	if strings.Contains(coverURL, spotifySize640) {
 		return strings.Replace(coverURL, spotifySize640, spotifySizeMax, 1)
 	}
 
+	// Deezer CDN upgrade
+	if strings.Contains(coverURL, "cdn-images.dzcdn.net") {
+		return upgradeDeezerCover(coverURL)
+	}
+
 	return coverURL
 }
 
-// GetCoverFromSpotify gets cover URL from Spotify metadata
+func upgradeDeezerCover(coverURL string) string {
+	if !strings.Contains(coverURL, "cdn-images.dzcdn.net") {
+		return coverURL
+	}
+
+	// Replace any size pattern with 1800x1800
+	upgraded := deezerSizeRegex.ReplaceAllString(coverURL, "/1800x1800-000000-80-0-0.jpg")
+	if upgraded != coverURL {
+		GoLog("[Cover] Deezer: upgraded to 1800x1800")
+	}
+	return upgraded
+}
+
 func GetCoverFromSpotify(imageURL string, maxQuality bool) string {
 	if imageURL == "" {
 		return ""

go_backend/deezer.go

@@ -22,27 +22,23 @@ const (
 
 	deezerCacheTTL = 10 * time.Minute
 
-	// Parallel ISRC fetching settings
+	deezerMaxParallelISRC = 10
-	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
+	isrcCache   map[string]string
 	cacheMu     sync.RWMutex
 }
 
-// Singleton instance
 var (
 	deezerClient     *DeezerClient
 	deezerClientOnce sync.Once
 )
 
-// GetDeezerClient returns singleton Deezer client
 func GetDeezerClient() *DeezerClient {
 	deezerClientOnce.Do(func() {
 		deezerClient = &DeezerClient{
@@ -56,16 +52,15 @@ func GetDeezerClient() *DeezerClient {
 	return deezerClient
 }
 
-// Deezer API response types
 type deezerTrack struct {
 	ID            int64             `json:"id"`
 	Title         string            `json:"title"`
-	Duration      int               `json:"duration"` // in seconds
+	Duration      int               `json:"duration"`
 	TrackPosition int               `json:"track_position"`
 	DiskNumber    int               `json:"disk_number"`
 	ISRC          string            `json:"isrc"`
 	Link          string            `json:"link"`
-	ReleaseDate   string            `json:"release_date"` // Sometimes at track level
+	ReleaseDate   string            `json:"release_date"`
 	Artist        deezerArtist      `json:"artist"`
 	Album         deezerAlbumSimple `json:"album"`
 	Contributors  []deezerArtist    `json:"contributors"`
@@ -88,12 +83,10 @@ type deezerAlbumSimple struct {
 	CoverMedium string `json:"cover_medium"`
 	CoverBig    string `json:"cover_big"`
 	CoverXL     string `json:"cover_xl"`
-	ReleaseDate string `json:"release_date"` // Sometimes at album level
+	ReleaseDate string `json:"release_date"`
+	RecordType  string `json:"record_type"`
 }
 
-// ... (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 {
@@ -115,7 +108,6 @@ func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
 		albumImage = track.Album.Cover
 	}
 
-	// Try to find release date
 	releaseDate := track.ReleaseDate
 	if releaseDate == "" {
 		releaseDate = track.Album.ReleaseDate
@@ -129,7 +121,7 @@ func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
 		AlbumArtist: track.Artist.Name,
 		DurationMS:  track.Duration * 1000,
 		Images:      albumImage,
-		ReleaseDate: releaseDate, // Added this
+		ReleaseDate: releaseDate,
 		TrackNumber: track.TrackPosition,
 		DiscNumber:  track.DiskNumber,
 		ExternalURL: track.Link,
@@ -137,16 +129,25 @@ func (c *DeezerClient) convertTrack(track deezerTrack) TrackMetadata {
 	}
 }
 
+type deezerGenre struct {
+	ID   int    `json:"id"`
+	Name string `json:"name"`
+}
+
 type deezerAlbumFull struct {
-	ID           int64          `json:"id"`
+	ID          int64  `json:"id"`
-	Title        string         `json:"title"`
+	Title       string `json:"title"`
-	Cover        string         `json:"cover"`
+	Cover       string `json:"cover"`
-	CoverMedium  string         `json:"cover_medium"`
+	CoverMedium string `json:"cover_medium"`
-	CoverBig     string         `json:"cover_big"`
+	CoverBig    string `json:"cover_big"`
-	CoverXL      string         `json:"cover_xl"`
+	CoverXL     string `json:"cover_xl"`
-	ReleaseDate  string         `json:"release_date"`
+	ReleaseDate string `json:"release_date"`
-	NbTracks     int            `json:"nb_tracks"`
+	NbTracks    int    `json:"nb_tracks"`
-	RecordType   string         `json:"record_type"` // album, single, ep, compile
+	RecordType  string `json:"record_type"`
+	Label       string `json:"label"`
+	Genres      struct {
+		Data []deezerGenre `json:"data"`
+	} `json:"genres"`
 	Artist       deezerArtist   `json:"artist"`
 	Contributors []deezerArtist `json:"contributors"`
 	Tracks       struct {
@@ -181,12 +182,38 @@ type deezerPlaylistFull struct {
 	} `json:"tracks"`
 }
 
-// SearchAll searches for tracks and artists on Deezer
+func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit, artistLimit int, filter string) (*SearchAllResult, error) {
-// NOTE: ISRC is NOT fetched during search for performance - use GetTrackISRC when needed for download
+	GoLog("[Deezer] SearchAll: query=%q, trackLimit=%d, artistLimit=%d, filter=%q\n", query, trackLimit, artistLimit, filter)
-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)
+	albumLimit := 5
+	playlistLimit := 5
+
+	if filter != "" {
+		switch filter {
+		case "track":
+			trackLimit = 50
+			artistLimit = 0
+			albumLimit = 0
+			playlistLimit = 0
+		case "artist":
+			trackLimit = 0
+			artistLimit = 20
+			albumLimit = 0
+			playlistLimit = 0
+		case "album":
+			trackLimit = 0
+			artistLimit = 0
+			albumLimit = 20
+			playlistLimit = 0
+		case "playlist":
+			trackLimit = 0
+			artistLimit = 0
+			albumLimit = 0
+			playlistLimit = 20
+		}
+	}
+
+	cacheKey := fmt.Sprintf("deezer:all:%s:%d:%d:%d:%d:%s", query, trackLimit, artistLimit, albumLimit, playlistLimit, filter)
 
 	c.cacheMu.RLock()
 	if entry, ok := c.searchCache[cacheKey]; ok && !entry.isExpired() {
@@ -197,73 +224,190 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 	c.cacheMu.RUnlock()
 
 	result := &SearchAllResult{
-		Tracks:  make([]TrackMetadata, 0),
+		Tracks:    make([]TrackMetadata, 0, trackLimit),
-		Artists: make([]SearchArtistResult, 0),
+		Artists:   make([]SearchArtistResult, 0, artistLimit),
+		Albums:    make([]SearchAlbumResult, 0, albumLimit),
+		Playlists: make([]SearchPlaylistResult, 0, playlistLimit),
 	}
 
-	// Search tracks - NO ISRC fetch for performance
+	if trackLimit > 0 {
-	trackURL := fmt.Sprintf("%s/track?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), trackLimit)
+		trackURL := fmt.Sprintf("%s/track?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), trackLimit)
-	GoLog("[Deezer] Fetching tracks from: %s\n", trackURL)
+		GoLog("[Deezer] Fetching tracks from: %s\n", trackURL)
 
-	var trackResp struct {
+		var trackResp struct {
-		Data  []deezerTrack `json:"data"`
+			Data  []deezerTrack `json:"data"`
-		Error *struct {
+			Error *struct {
-			Type    string `json:"type"`
+				Type    string `json:"type"`
-			Message string `json:"message"`
+				Message string `json:"message"`
-			Code    int    `json:"code"`
+				Code    int    `json:"code"`
-		} `json:"error"`
+			} `json:"error"`
-	}
+		}
-	if err := c.getJSON(ctx, trackURL, &trackResp); err != nil {
+		if err := c.getJSON(ctx, trackURL, &trackResp); err != nil {
-		GoLog("[Deezer] Track search failed: %v\n", err)
+			GoLog("[Deezer] Track search failed: %v\n", err)
-		return nil, fmt.Errorf("deezer track search failed: %w", err)
+			return nil, fmt.Errorf("deezer track search failed: %w", err)
-	}
+		}
-
+
-	if trackResp.Error != nil {
+		if trackResp.Error != nil {
-		GoLog("[Deezer] API error: type=%s, code=%d, message=%s\n", trackResp.Error.Type, trackResp.Error.Code, trackResp.Error.Message)
+			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)
+			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))
+		GoLog("[Deezer] Got %d tracks from API\n", len(trackResp.Data))
-
+
-	for _, track := range trackResp.Data {
+		for _, track := range trackResp.Data {
-		// Convert directly without fetching ISRC - much faster
+			result.Tracks = append(result.Tracks, c.convertTrack(track))
-		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))
+	if artistLimit > 0 {
+		artistURL := fmt.Sprintf("%s/artist?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), artistLimit)
+		GoLog("[Deezer] Fetching artists from: %s\n", artistURL)
+
+		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)
+		}
+	}
+
+	if albumLimit > 0 {
+		albumURL := fmt.Sprintf("%s/album?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), albumLimit)
+		GoLog("[Deezer] Fetching albums from: %s\n", albumURL)
+
+		var albumResp struct {
+			Data []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"`
+				NbTracks    int          `json:"nb_tracks"`
+				ReleaseDate string       `json:"release_date"`
+				RecordType  string       `json:"record_type"`
+				Artist      deezerArtist `json:"artist"`
+			} `json:"data"`
+			Error *struct {
+				Type    string `json:"type"`
+				Message string `json:"message"`
+				Code    int    `json:"code"`
+			} `json:"error"`
+		}
+		if err := c.getJSON(ctx, albumURL, &albumResp); err == nil {
+			if albumResp.Error != nil {
+				GoLog("[Deezer] Album API error: type=%s, code=%d, message=%s\n", albumResp.Error.Type, albumResp.Error.Code, albumResp.Error.Message)
+			} else {
+				GoLog("[Deezer] Got %d albums from API\n", len(albumResp.Data))
+				for _, album := range albumResp.Data {
+					coverURL := album.CoverXL
+					if coverURL == "" {
+						coverURL = album.CoverBig
+					}
+					if coverURL == "" {
+						coverURL = album.CoverMedium
+					}
+					if coverURL == "" {
+						coverURL = album.Cover
+					}
+
+					albumType := album.RecordType
+					if albumType == "compile" {
+						albumType = "compilation"
+					}
+
+					result.Albums = append(result.Albums, SearchAlbumResult{
+						ID:          fmt.Sprintf("deezer:%d", album.ID),
+						Name:        album.Title,
+						Artists:     album.Artist.Name,
+						Images:      coverURL,
+						ReleaseDate: album.ReleaseDate,
+						TotalTracks: album.NbTracks,
+						AlbumType:   albumType,
+					})
+				}
+			}
+		} else {
+			GoLog("[Deezer] Album search failed: %v\n", err)
+		}
+	}
+
+	if playlistLimit > 0 {
+		playlistURL := fmt.Sprintf("%s/playlist?q=%s&limit=%d", deezerSearchURL, url.QueryEscape(query), playlistLimit)
+		GoLog("[Deezer] Fetching playlists from: %s\n", playlistURL)
+
+		var playlistResp struct {
+			Data []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"`
+				User          struct {
+					Name string `json:"name"`
+				} `json:"user"`
+			} `json:"data"`
+			Error *struct {
+				Type    string `json:"type"`
+				Message string `json:"message"`
+				Code    int    `json:"code"`
+			} `json:"error"`
+		}
+		if err := c.getJSON(ctx, playlistURL, &playlistResp); err == nil {
+			if playlistResp.Error != nil {
+				GoLog("[Deezer] Playlist API error: type=%s, code=%d, message=%s\n", playlistResp.Error.Type, playlistResp.Error.Code, playlistResp.Error.Message)
+			} else {
+				GoLog("[Deezer] Got %d playlists from API\n", len(playlistResp.Data))
+				for _, playlist := range playlistResp.Data {
+					pictureURL := playlist.PictureXL
+					if pictureURL == "" {
+						pictureURL = playlist.PictureBig
+					}
+					if pictureURL == "" {
+						pictureURL = playlist.PictureMedium
+					}
+					if pictureURL == "" {
+						pictureURL = playlist.Picture
+					}
+
+					result.Playlists = append(result.Playlists, SearchPlaylistResult{
+						ID:          fmt.Sprintf("deezer:%d", playlist.ID),
+						Name:        playlist.Title,
+						Owner:       playlist.User.Name,
+						Images:      pictureURL,
+						TotalTracks: playlist.NbTracks,
+					})
+				}
+			}
+		} else {
+			GoLog("[Deezer] Playlist search failed: %v\n", err)
+		}
+	}
+
+	GoLog("[Deezer] SearchAll complete: %d tracks, %d artists, %d albums, %d playlists\n", len(result.Tracks), len(result.Artists), len(result.Albums), len(result.Playlists))
 
-	// Cache result
 	c.cacheMu.Lock()
 	c.searchCache[cacheKey] = &cacheEntry{
 		data:      result,
@@ -274,7 +418,6 @@ func (c *DeezerClient) SearchAll(ctx context.Context, query string, trackLimit,
 	return result, nil
 }
 
-// GetTrack fetches a single track by Deezer ID
 func (c *DeezerClient) GetTrack(ctx context.Context, trackID string) (*TrackResponse, error) {
 	trackURL := fmt.Sprintf(deezerTrackURL, trackID)
 
@@ -288,8 +431,6 @@ func (c *DeezerClient) GetTrack(ctx context.Context, trackID string) (*TrackResp
 	}, 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() {
@@ -315,28 +456,75 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 		artistName = strings.Join(names, ", ")
 	}
 
+	var genres []string
+	for _, g := range album.Genres.Data {
+		if g.Name != "" {
+			genres = append(genres, g.Name)
+		}
+	}
+	genreStr := strings.Join(genres, ", ")
+
 	info := AlbumInfoMetadata{
 		TotalTracks: album.NbTracks,
 		Name:        album.Title,
 		ReleaseDate: album.ReleaseDate,
 		Artists:     artistName,
+		ArtistId:    fmt.Sprintf("deezer:%d", album.Artist.ID),
 		Images:      albumImage,
+		Genre:       genreStr,
+		Label:       album.Label,
 	}
 
-	// Fetch ISRCs in parallel
+	allTracks := album.Tracks.Data
-	isrcMap := c.fetchISRCsParallel(ctx, album.Tracks.Data)
 
-	tracks := make([]AlbumTrackMetadata, 0, len(album.Tracks.Data))
+	if album.NbTracks > len(allTracks) {
-	// Normalize record_type (Deezer uses "compile" instead of "compilation")
+		GoLog("[Deezer] Album has %d tracks but only got %d, fetching remaining...", album.NbTracks, len(allTracks))
+
+		tracksURL := fmt.Sprintf("%s/tracks?limit=100&index=%d", fmt.Sprintf(deezerAlbumURL, albumID), len(allTracks))
+
+		for len(allTracks) < album.NbTracks {
+			var tracksResp struct {
+				Data []deezerTrack `json:"data"`
+				Next string        `json:"next"`
+			}
+
+			if err := c.getJSON(ctx, tracksURL, &tracksResp); err != nil {
+				GoLog("[Deezer] Warning: failed to fetch album tracks page: %v", err)
+				break
+			}
+
+			if len(tracksResp.Data) == 0 {
+				break
+			}
+
+			allTracks = append(allTracks, tracksResp.Data...)
+
+			if tracksResp.Next == "" {
+				break
+			}
+			tracksURL = tracksResp.Next
+		}
+
+		GoLog("[Deezer] Fetched total %d tracks for album", len(allTracks))
+	}
+
+	isrcMap := c.fetchISRCsParallel(ctx, allTracks)
+
+	tracks := make([]AlbumTrackMetadata, 0, len(allTracks))
 	albumType := album.RecordType
 	if albumType == "compile" {
 		albumType = "compilation"
 	}
 
-	for _, track := range album.Tracks.Data {
+	for i, track := range allTracks {
 		trackIDStr := fmt.Sprintf("%d", track.ID)
 		isrc := isrcMap[trackIDStr]
 
+		trackNum := track.TrackPosition
+		if trackNum == 0 {
+			trackNum = i + 1
+		}
+
 		tracks = append(tracks, AlbumTrackMetadata{
 			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
 			Artists:     track.Artist.Name,
@@ -346,7 +534,7 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 			DurationMS:  track.Duration * 1000,
 			Images:      albumImage,
 			ReleaseDate: album.ReleaseDate,
-			TrackNumber: track.TrackPosition,
+			TrackNumber: trackNum,
 			TotalTracks: album.NbTracks,
 			DiscNumber:  track.DiskNumber,
 			ExternalURL: track.Link,
@@ -371,7 +559,6 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 	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() {
@@ -380,7 +567,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 	}
 	c.cacheMu.RUnlock()
 
-	// Fetch artist info
 	artistURL := fmt.Sprintf(deezerArtistURL, artistID)
 	var artist deezerArtistFull
 	if err := c.getJSON(ctx, artistURL, &artist); err != nil {
@@ -395,7 +581,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 		Popularity: 0,
 	}
 
-	// Fetch artist albums
 	albumsURL := fmt.Sprintf("%s/albums?limit=100", fmt.Sprintf(deezerArtistURL, artistID))
 	var albumsResp struct {
 		Data []struct {
@@ -407,7 +592,7 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 			CoverMedium string `json:"cover_medium"`
 			CoverBig    string `json:"cover_big"`
 			CoverXL     string `json:"cover_xl"`
-			RecordType  string `json:"record_type"` // album, single, ep, compile
+			RecordType  string `json:"record_type"`
 		} `json:"data"`
 	}
 
@@ -457,8 +642,6 @@ func (c *DeezerClient) GetArtist(ctx context.Context, artistID string) (*ArtistR
 	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)
 
@@ -481,11 +664,43 @@ func (c *DeezerClient) GetPlaylist(ctx context.Context, playlistID string) (*Pla
 	info.Owner.Name = playlist.Title
 	info.Owner.Images = playlistImage
 
-	// Fetch ISRCs in parallel
+	allTracks := playlist.Tracks.Data
-	isrcMap := c.fetchISRCsParallel(ctx, playlist.Tracks.Data)
 
-	tracks := make([]AlbumTrackMetadata, 0, len(playlist.Tracks.Data))
+	if playlist.NbTracks > len(allTracks) {
-	for _, track := range playlist.Tracks.Data {
+		GoLog("[Deezer] Playlist has %d tracks but only got %d, fetching remaining...", playlist.NbTracks, len(allTracks))
+
+		tracksURL := fmt.Sprintf("%s/tracks?limit=100&index=%d", fmt.Sprintf(deezerPlaylistURL, playlistID), len(allTracks))
+
+		for len(allTracks) < playlist.NbTracks {
+			var tracksResp struct {
+				Data []deezerTrack `json:"data"`
+				Next string        `json:"next"`
+			}
+
+			if err := c.getJSON(ctx, tracksURL, &tracksResp); err != nil {
+				GoLog("[Deezer] Warning: failed to fetch playlist tracks page: %v", err)
+				break
+			}
+
+			if len(tracksResp.Data) == 0 {
+				break
+			}
+
+			allTracks = append(allTracks, tracksResp.Data...)
+
+			if tracksResp.Next == "" {
+				break
+			}
+			tracksURL = tracksResp.Next
+		}
+
+		GoLog("[Deezer] Fetched total %d tracks for playlist", len(allTracks))
+	}
+
+	isrcMap := c.fetchISRCsParallel(ctx, allTracks)
+
+	tracks := make([]AlbumTrackMetadata, 0, len(allTracks))
+	for _, track := range allTracks {
 		albumImage := track.Album.CoverXL
 		if albumImage == "" {
 			albumImage = track.Album.CoverBig
@@ -520,15 +735,11 @@ func (c *DeezerClient) GetPlaylist(ctx context.Context, playlistID string) (*Pla
 	}, 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"`
@@ -543,7 +754,6 @@ func (c *DeezerClient) SearchByISRC(ctx context.Context, isrc string) (*TrackMet
 		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)
 	}
@@ -561,16 +771,25 @@ func (c *DeezerClient) fetchFullTrack(ctx context.Context, trackID string) (*dee
 	return &track, nil
 }
 
-// fetchISRCsParallel fetches ISRCs for multiple tracks in parallel with caching
 func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTrack) map[string]string {
-	result := make(map[string]string)
+	result := make(map[string]string, len(tracks))
 	var resultMu sync.Mutex
 
-	// First, check cache for existing ISRCs
 	var tracksToFetch []deezerTrack
+	var directISRCs map[string]string
 	c.cacheMu.RLock()
 	for _, track := range tracks {
 		trackIDStr := fmt.Sprintf("%d", track.ID)
+		if track.ISRC != "" {
+			result[trackIDStr] = track.ISRC
+			if _, ok := c.isrcCache[trackIDStr]; !ok {
+				if directISRCs == nil {
+					directISRCs = make(map[string]string)
+				}
+				directISRCs[trackIDStr] = track.ISRC
+			}
+			continue
+		}
 		if isrc, ok := c.isrcCache[trackIDStr]; ok {
 			result[trackIDStr] = isrc
 		} else {
@@ -578,12 +797,18 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 		}
 	}
 	c.cacheMu.RUnlock()
+	if len(directISRCs) > 0 {
+		c.cacheMu.Lock()
+		for trackIDStr, isrc := range directISRCs {
+			c.isrcCache[trackIDStr] = isrc
+		}
+		c.cacheMu.Unlock()
+	}
 
 	if len(tracksToFetch) == 0 {
 		return result
 	}
 
-	// Use semaphore to limit concurrent requests
 	sem := make(chan struct{}, deezerMaxParallelISRC)
 	var wg sync.WaitGroup
 
@@ -592,7 +817,6 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 		go func(t deezerTrack) {
 			defer wg.Done()
 
-			// Acquire semaphore
 			select {
 			case sem <- struct{}{}:
 				defer func() { <-sem }()
@@ -606,7 +830,6 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 				return
 			}
 
-			// Store in result and cache
 			resultMu.Lock()
 			result[trackIDStr] = fullTrack.ISRC
 			resultMu.Unlock()
@@ -621,10 +844,7 @@ func (c *DeezerClient) fetchISRCsParallel(ctx context.Context, tracks []deezerTr
 	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()
@@ -632,13 +852,11 @@ func (c *DeezerClient) GetTrackISRC(ctx context.Context, trackID string) (string
 	}
 	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()
@@ -685,6 +903,94 @@ func (c *DeezerClient) getBestAlbumImage(album deezerAlbumFull) string {
 	return album.Cover
 }
 
+type AlbumExtendedMetadata struct {
+	Genre string
+	Label string
+}
+
+func (c *DeezerClient) GetAlbumExtendedMetadata(ctx context.Context, albumID string) (*AlbumExtendedMetadata, error) {
+	if albumID == "" {
+		return nil, fmt.Errorf("empty album ID")
+	}
+
+	cacheKey := fmt.Sprintf("album_meta:%s", albumID)
+	c.cacheMu.RLock()
+	if entry, ok := c.searchCache[cacheKey]; ok && !entry.isExpired() {
+		c.cacheMu.RUnlock()
+		return entry.data.(*AlbumExtendedMetadata), nil
+	}
+	c.cacheMu.RUnlock()
+
+	albumURL := fmt.Sprintf(deezerAlbumURL, albumID)
+
+	var album deezerAlbumFull
+	if err := c.getJSON(ctx, albumURL, &album); err != nil {
+		return nil, fmt.Errorf("failed to fetch album: %w", err)
+	}
+
+	var genres []string
+	for _, g := range album.Genres.Data {
+		if g.Name != "" {
+			genres = append(genres, g.Name)
+		}
+	}
+
+	result := &AlbumExtendedMetadata{
+		Genre: strings.Join(genres, ", "),
+		Label: album.Label,
+	}
+
+	c.cacheMu.Lock()
+	c.searchCache[cacheKey] = &cacheEntry{
+		data:      result,
+		expiresAt: time.Now().Add(deezerCacheTTL),
+	}
+	c.cacheMu.Unlock()
+
+	GoLog("[Deezer] Album metadata fetched - Genre: %s, Label: %s\n", result.Genre, result.Label)
+
+	return result, nil
+}
+
+func (c *DeezerClient) GetTrackAlbumID(ctx context.Context, trackID string) (string, error) {
+	trackURL := fmt.Sprintf(deezerTrackURL, trackID)
+
+	var track deezerTrack
+	if err := c.getJSON(ctx, trackURL, &track); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%d", track.Album.ID), nil
+}
+
+func (c *DeezerClient) GetExtendedMetadataByTrackID(ctx context.Context, trackID string) (*AlbumExtendedMetadata, error) {
+	albumID, err := c.GetTrackAlbumID(ctx, trackID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get album ID: %w", err)
+	}
+
+	return c.GetAlbumExtendedMetadata(ctx, albumID)
+}
+
+func (c *DeezerClient) GetExtendedMetadataByISRC(ctx context.Context, isrc string) (*AlbumExtendedMetadata, error) {
+	if isrc == "" {
+		return nil, fmt.Errorf("empty ISRC")
+	}
+
+	track, err := c.SearchByISRC(ctx, isrc)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find track by ISRC: %w", err)
+	}
+
+	deezerID := strings.TrimPrefix(track.SpotifyID, "deezer:")
+
+	if deezerID == "" {
+		return nil, fmt.Errorf("track found but no Deezer ID")
+	}
+
+	return c.GetExtendedMetadataByTrackID(ctx, deezerID)
+}
+
 func (c *DeezerClient) getJSON(ctx context.Context, endpoint string, dst interface{}) error {
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
 	if err != nil {
@@ -711,7 +1017,6 @@ func (c *DeezerClient) getJSON(ctx context.Context, endpoint string, dst interfa
 	return json.Unmarshal(body, dst)
 }
 
-// parseDeezerURL is internal function, returns type and ID
 func parseDeezerURL(input string) (string, string, error) {
 	trimmed := strings.TrimSpace(input)
 	if trimmed == "" {
@@ -729,7 +1034,6 @@ func parseDeezerURL(input string) (string, string, error) {
 
 	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:]
 	}

go_backend/duplicate.go

@@ -10,7 +10,6 @@ import (
 	"time"
 )
 
-// ISRCIndex holds a cached map of ISRC -> file path for fast duplicate checking
 type ISRCIndex struct {
 	index     map[string]string // ISRC (uppercase) -> file path
 	outputDir string
@@ -18,30 +17,42 @@ type ISRCIndex struct {
 	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
+	isrcBuildingMu   sync.Map // Per-directory build lock to prevent concurrent builds
+	isrcIndexTTL     = 5 * time.Minute
 )
 
-// GetISRCIndex returns or builds an ISRC index for the given directory
 func GetISRCIndex(outputDir string) *ISRCIndex {
+	// Fast path: check cache first
 	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
+	// Slow path: need to build index
+	// Use per-directory mutex to prevent multiple goroutines from building simultaneously
+	buildLock, _ := isrcBuildingMu.LoadOrStore(outputDir, &sync.Mutex{})
+	mu := buildLock.(*sync.Mutex)
+	mu.Lock()
+	defer mu.Unlock()
+
+	// Double-check cache after acquiring lock (another goroutine may have built it)
+	isrcIndexCacheMu.RLock()
+	idx, exists = isrcIndexCache[outputDir]
+	isrcIndexCacheMu.RUnlock()
+
+	if exists && time.Since(idx.buildTime) < isrcIndexTTL {
+		return idx
+	}
+
 	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),
@@ -56,7 +67,6 @@ func buildISRCIndex(outputDir string) *ISRCIndex {
 	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
@@ -67,22 +77,19 @@ func buildISRCIndex(outputDir string) *ISRCIndex {
 			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", 
+	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()
@@ -90,7 +97,6 @@ func buildISRCIndex(outputDir string) *ISRCIndex {
 	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
@@ -103,14 +109,22 @@ func (idx *ISRCIndex) lookup(isrc string) (string, bool) {
 	return path, exists
 }
 
-// Lookup checks if an ISRC exists in the index (gomobile compatible)
+func (idx *ISRCIndex) remove(isrc string) {
-// Returns filepath if found, empty string if not found
+	if isrc == "" {
+		return
+	}
+
+	idx.mu.Lock()
+	defer idx.mu.Unlock()
+
+	delete(idx.index, strings.ToUpper(isrc))
+}
+
 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
@@ -122,33 +136,37 @@ func (idx *ISRCIndex) Add(isrc, filePath string) {
 	idx.index[strings.ToUpper(isrc)] = filePath
 }
 
-// InvalidateCache clears the ISRC index cache for a directory
 func InvalidateISRCCache(outputDir string) {
 	isrcIndexCacheMu.Lock()
 	delete(isrcIndexCache, outputDir)
 	isrcIndexCacheMu.Unlock()
 }
 
-// checkISRCExistsInternal checks if a file with the given ISRC exists (internal use)
-// Uses ISRC index for fast lookup
 func checkISRCExistsInternal(outputDir, isrc string) (string, bool) {
 	if isrc == "" || outputDir == "" {
 		return "", false
 	}
 
-	// Use index for fast lookup
 	idx := GetISRCIndex(outputDir)
-	return idx.lookup(isrc)
+	filePath, exists := idx.lookup(isrc)
+	if !exists {
+		return "", false
+	}
+
+	if !CheckFileExists(filePath) {
+		// Stale index entry; remove it and return not found.
+		idx.remove(isrc)
+		return "", false
+	}
+
+	return filePath, true
 }
 
-// CheckISRCExists is the exported version for gomobile (returns string, error)
-// Returns the filepath if exists, empty string if not
 func CheckISRCExists(outputDir, isrc string) (string, error) {
 	filepath, _ := checkISRCExistsInternal(outputDir, isrc)
 	return filepath, nil
 }
 
-// CheckFileExists checks if a file with the given name exists
 func CheckFileExists(filePath string) bool {
 	info, err := os.Stat(filePath)
 	if err != nil {
@@ -157,7 +175,6 @@ func CheckFileExists(filePath string) bool {
 	return !info.IsDir() && info.Size() > 0
 }
 
-// FileExistenceResult represents the result of checking if a file exists
 type FileExistenceResult struct {
 	ISRC       string `json:"isrc"`
 	Exists     bool   `json:"exists"`
@@ -166,11 +183,7 @@ type FileExistenceResult struct {
 	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"`
@@ -182,10 +195,8 @@ func CheckFilesExistParallel(outputDir string, tracksJSON string) (string, error
 
 	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)
@@ -216,7 +227,6 @@ func CheckFilesExistParallel(outputDir string, tracksJSON string) (string, error
 
 	wg.Wait()
 
-	// Return results as JSON
 	resultJSON, err := json.Marshal(results)
 	if err != nil {
 		return "", fmt.Errorf("failed to marshal results: %w", err)
@@ -225,8 +235,6 @@ func CheckFilesExistParallel(outputDir string, tracksJSON string) (string, error
 	return string(resultJSON), nil
 }
 
-// PreBuildISRCIndex pre-builds the ISRC index for a directory
-// Call this when app starts or when entering album/playlist screen
 func PreBuildISRCIndex(outputDir string) error {
 	if outputDir == "" {
 		return fmt.Errorf("output directory is required")
@@ -236,8 +244,6 @@ func PreBuildISRCIndex(outputDir string) error {
 	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

go_backend/extension_manager.go

@@ -1,4 +1,3 @@
-// Package gobackend provides extension management functionality
 package gobackend
 
 import (
@@ -15,14 +14,10 @@ import (
 	"github.com/dop251/goja"
 )
 
-// compareVersions compares two semantic version strings
-// Returns: -1 if v1 < v2, 0 if v1 == v2, 1 if v1 > v2
 func compareVersions(v1, v2 string) int {
-	// Parse version parts
 	parts1 := strings.Split(strings.TrimPrefix(v1, "v"), ".")
 	parts2 := strings.Split(strings.TrimPrefix(v2, "v"), ".")
 
-	// Pad shorter version with zeros
 	maxLen := len(parts1)
 	if len(parts2) > maxLen {
 		maxLen = len(parts2)
@@ -48,19 +43,18 @@ func compareVersions(v1, v2 string) int {
 	return 0
 }
 
-// LoadedExtension represents an extension that has been loaded into memory
 type LoadedExtension struct {
 	ID        string             `json:"id"`
 	Manifest  *ExtensionManifest `json:"manifest"`
-	VM        *goja.Runtime      `json:"-"` // Goja VM instance (not serialized)
+	VM        *goja.Runtime      `json:"-"`
+	VMMu      sync.Mutex         `json:"-"` // Mutex to prevent concurrent VM access
 	Enabled   bool               `json:"enabled"`
 	Error     string             `json:"error,omitempty"`
-	DataDir   string             `json:"data_dir"`   // Extension's data directory
+	DataDir   string             `json:"data_dir"`
-	SourceDir string             `json:"source_dir"` // Where extension files are extracted
+	SourceDir string             `json:"source_dir"`
-	IconPath  string             `json:"icon_path"`  // Full path to icon file (if exists)
+	IconPath  string             `json:"icon_path"`
 }
 
-// ExtensionManager manages all loaded extensions
 type ExtensionManager struct {
 	mu            sync.RWMutex
 	extensions    map[string]*LoadedExtension
@@ -68,13 +62,11 @@ type ExtensionManager struct {
 	dataDir       string // Base directory for extension data
 }
 
-// Global extension manager instance
 var (
 	globalExtManager     *ExtensionManager
 	globalExtManagerOnce sync.Once
 )
 
-// GetExtensionManager returns the global extension manager instance
 func GetExtensionManager() *ExtensionManager {
 	globalExtManagerOnce.Do(func() {
 		globalExtManager = &ExtensionManager{
@@ -84,7 +76,6 @@ func GetExtensionManager() *ExtensionManager {
 	return globalExtManager
 }
 
-// SetDirectories sets the extensions and data directories
 func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -92,7 +83,6 @@ func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	m.extensionsDir = extensionsDir
 	m.dataDir = dataDir
 
-	// Create directories if they don't exist
 	if err := os.MkdirAll(extensionsDir, 0755); err != nil {
 		return fmt.Errorf("failed to create extensions directory: %w", err)
 	}
@@ -103,9 +93,7 @@ func (m *ExtensionManager) SetDirectories(extensionsDir, dataDir string) error {
 	return nil
 }
 
-// LoadExtensionFromFile loads an extension from a .spotiflac-ext file
 func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtension, error) {
-	// Validate file extension
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
 		return nil, fmt.Errorf("Invalid file format. Please select a .spotiflac-ext file")
 	}
@@ -117,7 +105,6 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 	}
 	defer zipReader.Close()
 
-	// Find and read manifest.json
 	var manifestData []byte
 	var hasIndexJS bool
 	for _, file := range zipReader.File {
@@ -146,13 +133,11 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 		return nil, fmt.Errorf("Invalid extension package: index.js not found")
 	}
 
-	// Parse and validate manifest
 	manifest, err := ParseManifest(manifestData)
 	if err != nil {
 		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
-	// Check if extension already loaded - if so, try upgrade (check without holding lock for long)
 	m.mu.RLock()
 	existing, exists := m.extensions[manifest.Name]
 	var existingVersion string
@@ -164,7 +149,6 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 	m.mu.RUnlock()
 
 	if exists {
-		// Check if this is an upgrade
 		versionCompare := compareVersions(manifest.Version, existingVersion)
 		if versionCompare > 0 {
 			// This is an upgrade - call UpgradeExtension
@@ -176,29 +160,23 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 		}
 	}
 
-	// Now acquire write lock for the rest of the operation
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	// Double-check extension wasn't added while we were waiting for lock
 	if _, exists := m.extensions[manifest.Name]; exists {
 		return nil, fmt.Errorf("Extension '%s' was installed by another process", manifest.DisplayName)
 	}
 
-	// Create extension directory
 	extDir := filepath.Join(m.extensionsDir, manifest.Name)
 	if err := os.MkdirAll(extDir, 0755); err != nil {
 		return nil, fmt.Errorf("failed to create extension directory: %w", err)
 	}
 
-	// Extract all files (preserving directory structure)
 	for _, file := range zipReader.File {
 		if file.FileInfo().IsDir() {
 			continue
 		}
 
-		// Preserve relative path within the zip (support subdirectories)
-		// Clean the path to prevent path traversal attacks
 		relPath := filepath.Clean(file.Name)
 		if strings.HasPrefix(relPath, "..") || filepath.IsAbs(relPath) {
 			GoLog("[Extension] Skipping unsafe path in archive: %s\n", file.Name)
@@ -206,19 +184,16 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 		}
 		destPath := filepath.Join(extDir, relPath)
 
-		// Create parent directories if needed
 		destDir := filepath.Dir(destPath)
 		if err := os.MkdirAll(destDir, 0755); err != nil {
 			return nil, fmt.Errorf("failed to create directory %s: %w", destDir, err)
 		}
 
-		// Create destination file
 		destFile, err := os.Create(destPath)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create file %s: %w", destPath, err)
 		}
 
-		// Copy content
 		srcFile, err := file.Open()
 		if err != nil {
 			destFile.Close()
@@ -233,13 +208,11 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 		}
 	}
 
-	// Create data directory for extension
 	extDataDir := filepath.Join(m.dataDir, manifest.Name)
 	if err := os.MkdirAll(extDataDir, 0755); err != nil {
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	// Create loaded extension
 	ext := &LoadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
@@ -261,25 +234,20 @@ func (m *ExtensionManager) LoadExtensionFromFile(filePath string) (*LoadedExtens
 	return ext, nil
 }
 
-// initializeVM creates and initializes the Goja VM for an extension
 func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
-	// Create new Goja runtime
 	vm := goja.New()
 	ext.VM = vm
 
-	// Read index.js
 	indexPath := filepath.Join(ext.SourceDir, "index.js")
 	jsCode, err := os.ReadFile(indexPath)
 	if err != nil {
 		return fmt.Errorf("failed to read index.js: %w", err)
 	}
 
-	// Create extension runtime and register sandboxed APIs
 	runtime := NewExtensionRuntime(ext)
 	runtime.RegisterAPIs(vm)
 	runtime.RegisterGoBackendAPIs(vm)
 
-	// Set up console.log for debugging
 	console := vm.NewObject()
 	console.Set("log", func(call goja.FunctionCall) goja.Value {
 		args := make([]interface{}, len(call.Arguments))
@@ -291,12 +259,10 @@ func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
 	})
 	vm.Set("console", console)
 
-	// Set up registerExtension function
 	var registeredExtension goja.Value
 	vm.Set("registerExtension", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) > 0 {
 			registeredExtension = call.Arguments[0]
-			// Also set it as global 'extension' variable for later access
 			vm.Set("extension", call.Arguments[0])
 		}
 		return goja.Undefined()
@@ -316,7 +282,6 @@ func (m *ExtensionManager) initializeVM(ext *LoadedExtension) error {
 	return nil
 }
 
-// UnloadExtension unloads an extension by ID
 func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -344,8 +309,6 @@ func (m *ExtensionManager) UnloadExtension(extensionID string) error {
 	return nil
 }
 
-// GetExtension returns a loaded extension by ID
-// Returns error if extension not found (gomobile compatible)
 func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, error) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -357,7 +320,6 @@ func (m *ExtensionManager) GetExtension(extensionID string) (*LoadedExtension, e
 	return ext, nil
 }
 
-// GetAllExtensions returns all loaded extensions
 func (m *ExtensionManager) GetAllExtensions() []*LoadedExtension {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -369,7 +331,6 @@ func (m *ExtensionManager) GetAllExtensions() []*LoadedExtension {
 	return result
 }
 
-// SetExtensionEnabled enables or disables an extension
 func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -391,7 +352,6 @@ func (m *ExtensionManager) SetExtensionEnabled(extensionID string, enabled bool)
 	return nil
 }
 
-// LoadExtensionsFromDirectory scans a directory and loads all valid extensions
 func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string, []error) {
 	var loaded []string
 	var errors []error
@@ -406,7 +366,6 @@ func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string
 
 	for _, entry := range entries {
 		if entry.IsDir() {
-			// Check if it's an extracted extension directory
 			manifestPath := filepath.Join(dirPath, entry.Name(), "manifest.json")
 			if _, err := os.Stat(manifestPath); err == nil {
 				ext, err := m.loadExtensionFromDirectory(filepath.Join(dirPath, entry.Name()))
@@ -418,7 +377,6 @@ func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string
 				}
 			}
 		} else if strings.HasSuffix(strings.ToLower(entry.Name()), ".spotiflac-ext") {
-			// Load from package file
 			ext, err := m.LoadExtensionFromFile(filepath.Join(dirPath, entry.Name()))
 			if err != nil {
 				GoLog("[Extension] Failed to load %s: %v\n", entry.Name(), err)
@@ -432,12 +390,10 @@ func (m *ExtensionManager) LoadExtensionsFromDirectory(dirPath string) ([]string
 	return loaded, errors
 }
 
-// loadExtensionFromDirectory loads an extension from an already extracted directory
 func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedExtension, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	// Read manifest
 	manifestPath := filepath.Join(dirPath, "manifest.json")
 	manifestData, err := os.ReadFile(manifestPath)
 	if err != nil {
@@ -450,25 +406,21 @@ func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedEx
 		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
-	// Check if index.js exists
 	indexPath := filepath.Join(dirPath, "index.js")
 	if _, err := os.Stat(indexPath); os.IsNotExist(err) {
 		return nil, fmt.Errorf("Extension is missing index.js file")
 	}
 
-	// Check if extension already loaded - skip silently (for directory loading on startup)
 	if existing, exists := m.extensions[manifest.Name]; exists {
 		GoLog("[Extension] Extension '%s' already loaded, skipping\n", manifest.DisplayName)
 		return existing, nil
 	}
 
-	// Create data directory for extension
 	extDataDir := filepath.Join(m.dataDir, manifest.Name)
 	if err := os.MkdirAll(extDataDir, 0755); err != nil {
 		return nil, fmt.Errorf("failed to create extension data directory: %w", err)
 	}
 
-	// Create loaded extension
 	ext := &LoadedExtension{
 		ID:        manifest.Name,
 		Manifest:  manifest,
@@ -499,7 +451,6 @@ func (m *ExtensionManager) loadExtensionFromDirectory(dirPath string) (*LoadedEx
 	return ext, nil
 }
 
-// RemoveExtension completely removes an extension (unload + delete files)
 func (m *ExtensionManager) RemoveExtension(extensionID string) error {
 	ext, err := m.GetExtension(extensionID)
 	if err != nil {
@@ -526,7 +477,6 @@ func (m *ExtensionManager) RemoveExtension(extensionID string) error {
 	return nil
 }
 
-// UpgradeExtension upgrades an existing extension from a new package file
 // Only allows upgrades (new version > current version), not downgrades
 func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension, error) {
 	// Validate file extension
@@ -541,7 +491,6 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 	}
 	defer zipReader.Close()
 
-	// Find and read manifest.json
 	var manifestData []byte
 	var hasIndexJS bool
 	for _, file := range zipReader.File {
@@ -570,13 +519,11 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 		return nil, fmt.Errorf("Invalid extension package: index.js not found")
 	}
 
-	// Parse and validate manifest
 	newManifest, err := ParseManifest(manifestData)
 	if err != nil {
 		return nil, fmt.Errorf("Invalid extension manifest: %w", err)
 	}
 
-	// Check if extension exists
 	m.mu.RLock()
 	existing, exists := m.extensions[newManifest.Name]
 	m.mu.RUnlock()
@@ -612,19 +559,15 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 		}
 	}
 
-	// Recreate extension directory
 	if err := os.MkdirAll(extDir, 0755); err != nil {
 		return nil, fmt.Errorf("failed to create extension directory: %w", err)
 	}
 
-	// Extract all files from new package (preserving directory structure)
 	for _, file := range zipReader.File {
 		if file.FileInfo().IsDir() {
 			continue
 		}
 
-		// Preserve relative path within the zip (support subdirectories)
-		// Clean the path to prevent path traversal attacks
 		relPath := filepath.Clean(file.Name)
 		if strings.HasPrefix(relPath, "..") || filepath.IsAbs(relPath) {
 			GoLog("[Extension] Skipping unsafe path in archive: %s\n", file.Name)
@@ -632,19 +575,16 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 		}
 		destPath := filepath.Join(extDir, relPath)
 
-		// Create parent directories if needed
 		destDir := filepath.Dir(destPath)
 		if err := os.MkdirAll(destDir, 0755); err != nil {
 			return nil, fmt.Errorf("failed to create directory %s: %w", destDir, err)
 		}
 
-		// Create destination file
 		destFile, err := os.Create(destPath)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create file %s: %w", destPath, err)
 		}
 
-		// Copy content
 		srcFile, err := file.Open()
 		if err != nil {
 			destFile.Close()
@@ -659,7 +599,6 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 		}
 	}
 
-	// Create new loaded extension (reusing data directory, preserving enabled state)
 	ext := &LoadedExtension{
 		ID:        newManifest.Name,
 		Manifest:  newManifest,
@@ -684,7 +623,6 @@ func (m *ExtensionManager) UpgradeExtension(filePath string) (*LoadedExtension,
 	return ext, nil
 }
 
-// ExtensionUpgradeInfo holds information about extension upgrade check
 type ExtensionUpgradeInfo struct {
 	ExtensionID    string `json:"extension_id"`
 	CurrentVersion string `json:"current_version"`
@@ -693,8 +631,6 @@ type ExtensionUpgradeInfo struct {
 	IsInstalled    bool   `json:"is_installed"`
 }
 
-// checkExtensionUpgradeInternal checks if a package file is an upgrade for an existing extension
-// Internal function that returns struct
 func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*ExtensionUpgradeInfo, error) {
 	// Validate file extension
 	if !strings.HasSuffix(strings.ToLower(filePath), ".spotiflac-ext") {
@@ -708,7 +644,6 @@ func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 	}
 	defer zipReader.Close()
 
-	// Find and read manifest.json
 	var manifestData []byte
 	for _, file := range zipReader.File {
 		name := filepath.Base(file.Name)
@@ -730,13 +665,11 @@ func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 		return nil, fmt.Errorf("manifest.json not found")
 	}
 
-	// Parse manifest
 	newManifest, err := ParseManifest(manifestData)
 	if err != nil {
 		return nil, fmt.Errorf("Invalid manifest: %w", err)
 	}
 
-	// Check if extension exists
 	m.mu.RLock()
 	existing, exists := m.extensions[newManifest.Name]
 	m.mu.RUnlock()
@@ -752,7 +685,6 @@ func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 		info.CurrentVersion = ""
 		info.CanUpgrade = false
 	} else {
-		// Compare versions
 		info.CurrentVersion = existing.Manifest.Version
 		info.CanUpgrade = compareVersions(newManifest.Version, existing.Manifest.Version) > 0
 	}
@@ -760,7 +692,6 @@ func (m *ExtensionManager) checkExtensionUpgradeInternal(filePath string) (*Exte
 	return info, nil
 }
 
-// CheckExtensionUpgradeJSON checks if a package file is an upgrade and returns JSON
 func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, error) {
 	info, err := m.checkExtensionUpgradeInternal(filePath)
 	if err != nil {
@@ -775,37 +706,36 @@ func (m *ExtensionManager) CheckExtensionUpgradeJSON(filePath string) (string, e
 	return string(jsonBytes), nil
 }
 
-// GetInstalledExtensionsJSON returns all extensions as JSON for Flutter
 func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	extensions := m.GetAllExtensions()
 
 	type ExtensionInfo struct {
-		ID                     string                `json:"id"`
+		ID                     string                 `json:"id"`
-		Name                   string                `json:"name"`
+		Name                   string                 `json:"name"`
-		DisplayName            string                `json:"display_name"`
+		DisplayName            string                 `json:"display_name"`
-		Version                string                `json:"version"`
+		Version                string                 `json:"version"`
-		Author                 string                `json:"author"`
+		Author                 string                 `json:"author"`
-		Description            string                `json:"description"`
+		Description            string                 `json:"description"`
-		Homepage               string                `json:"homepage,omitempty"`
+		Homepage               string                 `json:"homepage,omitempty"`
-		IconPath               string                `json:"icon_path,omitempty"`
+		IconPath               string                 `json:"icon_path,omitempty"`
-		Types                  []ExtensionType       `json:"types"`
+		Types                  []ExtensionType        `json:"types"`
-		Enabled                bool                  `json:"enabled"`
+		Enabled                bool                   `json:"enabled"`
-		Status                 string                `json:"status"`
+		Status                 string                 `json:"status"`
-		Error                  string                `json:"error_message,omitempty"`
+		Error                  string                 `json:"error_message,omitempty"`
-		Settings               []ExtensionSetting    `json:"settings,omitempty"`
+		Settings               []ExtensionSetting     `json:"settings,omitempty"`
-		QualityOptions         []QualityOption       `json:"quality_options,omitempty"`
+		QualityOptions         []QualityOption        `json:"quality_options,omitempty"`
-		Permissions            []string              `json:"permissions"`
+		Permissions            []string               `json:"permissions"`
-		HasMetadataProvider    bool                  `json:"has_metadata_provider"`
+		HasMetadataProvider    bool                   `json:"has_metadata_provider"`
-		HasDownloadProvider    bool                  `json:"has_download_provider"`
+		HasDownloadProvider    bool                   `json:"has_download_provider"`
-		SkipMetadataEnrichment bool                  `json:"skip_metadata_enrichment"`
+		SkipMetadataEnrichment bool                   `json:"skip_metadata_enrichment"`
-		SearchBehavior         *SearchBehaviorConfig `json:"search_behavior,omitempty"`
+		SearchBehavior         *SearchBehaviorConfig  `json:"search_behavior,omitempty"`
-		TrackMatching          *TrackMatchingConfig  `json:"track_matching,omitempty"`
+		TrackMatching          *TrackMatchingConfig   `json:"track_matching,omitempty"`
-		PostProcessing         *PostProcessingConfig `json:"post_processing,omitempty"`
+		PostProcessing         *PostProcessingConfig  `json:"post_processing,omitempty"`
+		Capabilities           map[string]interface{} `json:"capabilities,omitempty"`
 	}
 
 	infos := make([]ExtensionInfo, len(extensions))
 	for i, ext := range extensions {
-		// Build permissions list
 		permissions := []string{}
 		for _, domain := range ext.Manifest.Permissions.Network {
 			permissions = append(permissions, "network:"+domain)
@@ -822,7 +752,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 			status = "disabled"
 		}
 
-		// Check for icon file
 		iconPath := ""
 		if ext.Manifest.Icon != "" && ext.SourceDir != "" {
 			possibleIcon := filepath.Join(ext.SourceDir, ext.Manifest.Icon)
@@ -830,7 +759,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 				iconPath = possibleIcon
 			}
 		}
-		// Fallback: check for icon.png if not specified in manifest
 		if iconPath == "" && ext.SourceDir != "" {
 			possibleIcon := filepath.Join(ext.SourceDir, "icon.png")
 			if _, err := os.Stat(possibleIcon); err == nil {
@@ -860,6 +788,7 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 			SearchBehavior:         ext.Manifest.SearchBehavior,
 			TrackMatching:          ext.Manifest.TrackMatching,
 			PostProcessing:         ext.Manifest.PostProcessing,
+			Capabilities:           ext.Manifest.Capabilities,
 		}
 	}
 
@@ -871,9 +800,6 @@ func (m *ExtensionManager) GetInstalledExtensionsJSON() (string, error) {
 	return string(jsonBytes), nil
 }
 
-// ==================== Extension Lifecycle ====================
-
-// InitializeExtension calls the extension's initialize method with settings
 func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[string]interface{}) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -887,13 +813,11 @@ func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[
 		return fmt.Errorf("Extension failed to load. Please reinstall the extension")
 	}
 
-	// Convert settings to JSON for passing to JS
 	settingsJSON, err := json.Marshal(settings)
 	if err != nil {
 		return fmt.Errorf("Failed to save settings")
 	}
 
-	// Call initialize function
 	script := fmt.Sprintf(`
 		(function() {
 			var settings = %s;
@@ -917,7 +841,6 @@ func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[
 		return err
 	}
 
-	// Check result
 	if result != nil && !goja.IsUndefined(result) {
 		exported := result.Export()
 		if resultMap, ok := exported.(map[string]interface{}); ok {
@@ -938,7 +861,6 @@ func (m *ExtensionManager) InitializeExtension(extensionID string, settings map[
 	return nil
 }
 
-// CleanupExtension calls the extension's cleanup method
 func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
@@ -949,10 +871,9 @@ func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	}
 
 	if ext.VM == nil {
-		return nil // No VM, nothing to cleanup
+		return nil
 	}
 
-	// Call cleanup function
 	script := `
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.cleanup === 'function') {
@@ -973,7 +894,6 @@ func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 		return err
 	}
 
-	// Check result
 	if result != nil && !goja.IsUndefined(result) {
 		exported := result.Export()
 		if resultMap, ok := exported.(map[string]interface{}); ok {
@@ -992,7 +912,6 @@ func (m *ExtensionManager) CleanupExtension(extensionID string) error {
 	return nil
 }
 
-// UnloadAllExtensions unloads all extensions gracefully
 func (m *ExtensionManager) UnloadAllExtensions() {
 	m.mu.Lock()
 	extensionIDs := make([]string, 0, len(m.extensions))
@@ -1002,11 +921,64 @@ func (m *ExtensionManager) UnloadAllExtensions() {
 	m.mu.Unlock()
 
 	for _, id := range extensionIDs {
-		// Call cleanup first
 		m.CleanupExtension(id)
-		// Then unload
 		m.UnloadExtension(id)
 	}
 
 	GoLog("[Extension] All extensions unloaded\n")
 }
+
+func (m *ExtensionManager) InvokeAction(extensionID string, actionName string) (map[string]interface{}, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	ext, exists := m.extensions[extensionID]
+	if !exists {
+		return nil, fmt.Errorf("extension not found: %s", extensionID)
+	}
+
+	if ext.VM == nil {
+		return nil, fmt.Errorf("extension VM not initialized")
+	}
+
+	if !ext.Enabled {
+		return nil, fmt.Errorf("extension is disabled")
+	}
+
+	// Call the action function on the extension object
+	script := fmt.Sprintf(`
+		(function() {
+			if (typeof extension !== 'undefined' && typeof extension.%s === 'function') {
+				try {
+					var result = extension.%s();
+					if (result && typeof result.then === 'function') {
+						// Handle promise - return pending status
+						return { success: true, pending: true, message: 'Action started' };
+					}
+					return { success: true, result: result };
+				} catch (e) {
+					return { success: false, error: e.toString() };
+				}
+			}
+			return { success: false, error: 'Action function not found: %s' };
+		})()
+	`, actionName, actionName, actionName)
+
+	result, err := RunWithTimeoutAndRecover(ext.VM, script, DefaultJSTimeout)
+	if err != nil {
+		GoLog("[Extension] InvokeAction error for %s.%s: %v\n", extensionID, actionName, err)
+		return nil, fmt.Errorf("action failed: %v", err)
+	}
+
+	if result == nil || goja.IsUndefined(result) {
+		return map[string]interface{}{"success": true}, nil
+	}
+
+	exported := result.Export()
+	if resultMap, ok := exported.(map[string]interface{}); ok {
+		GoLog("[Extension] InvokeAction %s.%s result: %v\n", extensionID, actionName, resultMap)
+		return resultMap, nil
+	}
+
+	return map[string]interface{}{"success": true, "result": exported}, nil
+}

go_backend/extension_manifest.go

@@ -7,7 +7,6 @@ import (
 	"strings"
 )
 
-// ExtensionType represents the type of extension
 type ExtensionType string
 
 const (
@@ -15,7 +14,6 @@ const (
 	ExtensionTypeDownloadProvider ExtensionType = "download_provider"
 )
 
-// SettingType represents the type of a setting field
 type SettingType string
 
 const (
@@ -23,16 +21,15 @@ const (
 	SettingTypeNumber SettingType = "number"
 	SettingTypeBool   SettingType = "boolean"
 	SettingTypeSelect SettingType = "select"
+	SettingTypeButton SettingType = "button" // Action button that calls a JS function
 )
 
-// ExtensionPermissions defines what resources an extension can access
 type ExtensionPermissions struct {
-	Network []string `json:"network"` // List of allowed domains
+	Network []string `json:"network"`
-	Storage bool     `json:"storage"` // Whether extension can use storage API
+	Storage bool     `json:"storage"`
-	File    bool     `json:"file"`    // Whether extension can use file API
+	File    bool     `json:"file"`
 }
 
-// ExtensionSetting defines a configurable setting for an extension
 type ExtensionSetting struct {
 	Key         string      `json:"key"`
 	Type        SettingType `json:"type"`
@@ -41,18 +38,17 @@ type ExtensionSetting struct {
 	Required    bool        `json:"required,omitempty"`
 	Secret      bool        `json:"secret,omitempty"`
 	Default     interface{} `json:"default,omitempty"`
-	Options     []string    `json:"options,omitempty"` // For select type
+	Options     []string    `json:"options,omitempty"`
+	Action      string      `json:"action,omitempty"`
 }
 
-// QualityOption represents a quality option for download providers
 type QualityOption struct {
-	ID          string                   `json:"id"`                 // Unique identifier (e.g., "mp3_320", "opus_128")
+	ID          string                   `json:"id"`
-	Label       string                   `json:"label"`              // Display name (e.g., "MP3 320kbps")
+	Label       string                   `json:"label"`
-	Description string                   `json:"description"`        // Optional description (e.g., "Best quality MP3")
+	Description string                   `json:"description"`
-	Settings    []QualitySpecificSetting `json:"settings,omitempty"` // Quality-specific settings
+	Settings    []QualitySpecificSetting `json:"settings,omitempty"`
 }
 
-// QualitySpecificSetting represents a setting that's specific to a quality option
 type QualitySpecificSetting struct {
 	Key         string      `json:"key"`
 	Type        SettingType `json:"type"`
@@ -61,71 +57,72 @@ type QualitySpecificSetting struct {
 	Required    bool        `json:"required,omitempty"`
 	Secret      bool        `json:"secret,omitempty"`
 	Default     interface{} `json:"default,omitempty"`
-	Options     []string    `json:"options,omitempty"` // For select type
+	Options     []string    `json:"options,omitempty"`
+}
+
+type SearchFilter struct {
+	ID    string `json:"id"`
+	Label string `json:"label,omitempty"`
+	Icon  string `json:"icon,omitempty"`
 }
 
-// SearchBehaviorConfig defines custom search behavior for an extension
 type SearchBehaviorConfig struct {
-	Enabled         bool   `json:"enabled"`                   // Whether extension provides custom search
+	Enabled         bool           `json:"enabled"`
-	Placeholder     string `json:"placeholder,omitempty"`     // Placeholder text for search box
+	Placeholder     string         `json:"placeholder,omitempty"`
-	Primary         bool   `json:"primary,omitempty"`         // If true, show as primary search tab
+	Primary         bool           `json:"primary,omitempty"`
-	Icon            string `json:"icon,omitempty"`            // Icon for search tab
+	Icon            string         `json:"icon,omitempty"`
-	ThumbnailRatio  string `json:"thumbnailRatio,omitempty"`  // Thumbnail aspect ratio: "square" (1:1), "wide" (16:9), "portrait" (2:3)
+	ThumbnailRatio  string         `json:"thumbnailRatio,omitempty"`
-	ThumbnailWidth  int    `json:"thumbnailWidth,omitempty"`  // Custom thumbnail width in pixels
+	ThumbnailWidth  int            `json:"thumbnailWidth,omitempty"`
-	ThumbnailHeight int    `json:"thumbnailHeight,omitempty"` // Custom thumbnail height in pixels
+	ThumbnailHeight int            `json:"thumbnailHeight,omitempty"`
+	Filters         []SearchFilter `json:"filters,omitempty"`
 }
 
-// URLHandlerConfig defines custom URL handling for an extension
 type URLHandlerConfig struct {
-	Enabled  bool     `json:"enabled"`            // Whether extension handles URLs
+	Enabled  bool     `json:"enabled"`
-	Patterns []string `json:"patterns,omitempty"` // URL patterns to match (e.g., "music.youtube.com", "soundcloud.com")
+	Patterns []string `json:"patterns,omitempty"`
 }
 
-// TrackMatchingConfig defines custom track matching behavior
 type TrackMatchingConfig struct {
-	CustomMatching    bool   `json:"customMatching"`              // Whether extension handles matching
+	CustomMatching    bool   `json:"customMatching"`
-	Strategy          string `json:"strategy,omitempty"`          // "isrc", "name", "duration", "custom"
+	Strategy          string `json:"strategy,omitempty"`
-	DurationTolerance int    `json:"durationTolerance,omitempty"` // Tolerance in seconds for duration matching
+	DurationTolerance int    `json:"durationTolerance,omitempty"`
 }
 
-// PostProcessingHook defines a post-processing hook
 type PostProcessingHook struct {
-	ID               string   `json:"id"`                         // Unique identifier
+	ID               string   `json:"id"`
-	Name             string   `json:"name"`                       // Display name
+	Name             string   `json:"name"`
-	Description      string   `json:"description,omitempty"`      // Description
+	Description      string   `json:"description,omitempty"`
-	DefaultEnabled   bool     `json:"defaultEnabled,omitempty"`   // Whether enabled by default
+	DefaultEnabled   bool     `json:"defaultEnabled,omitempty"`
-	SupportedFormats []string `json:"supportedFormats,omitempty"` // Supported file formats (e.g., ["flac", "mp3"])
+	SupportedFormats []string `json:"supportedFormats,omitempty"`
 }
 
-// PostProcessingConfig defines post-processing capabilities
 type PostProcessingConfig struct {
-	Enabled bool                 `json:"enabled"`         // Whether extension provides post-processing
+	Enabled bool                 `json:"enabled"`
-	Hooks   []PostProcessingHook `json:"hooks,omitempty"` // Available hooks
+	Hooks   []PostProcessingHook `json:"hooks,omitempty"`
 }
 
-// ExtensionManifest represents the manifest.json of an extension
 type ExtensionManifest struct {
-	Name                   string                `json:"name"`
+	Name                   string                 `json:"name"`
-	DisplayName            string                `json:"displayName"`
+	DisplayName            string                 `json:"displayName"`
-	Version                string                `json:"version"`
+	Version                string                 `json:"version"`
-	Author                 string                `json:"author"`
+	Author                 string                 `json:"author"`
-	Description            string                `json:"description"`
+	Description            string                 `json:"description"`
-	Homepage               string                `json:"homepage,omitempty"`
+	Homepage               string                 `json:"homepage,omitempty"`
-	Icon                   string                `json:"icon,omitempty"` // Icon filename (e.g., "icon.png")
+	Icon                   string                 `json:"icon,omitempty"`
-	Types                  []ExtensionType       `json:"type"`
+	Types                  []ExtensionType        `json:"type"`
-	Permissions            ExtensionPermissions  `json:"permissions"`
+	Permissions            ExtensionPermissions   `json:"permissions"`
-	Settings               []ExtensionSetting    `json:"settings,omitempty"`
+	Settings               []ExtensionSetting     `json:"settings,omitempty"`
-	QualityOptions         []QualityOption       `json:"qualityOptions,omitempty"` // Custom quality options for download providers
+	QualityOptions         []QualityOption        `json:"qualityOptions,omitempty"`
-	MinAppVersion          string                `json:"minAppVersion,omitempty"`
+	MinAppVersion          string                 `json:"minAppVersion,omitempty"`
-	SkipMetadataEnrichment bool                  `json:"skipMetadataEnrichment,omitempty"` // If true, don't enrich metadata from Deezer/Spotify
+	SkipMetadataEnrichment bool                   `json:"skipMetadataEnrichment,omitempty"`
-	SkipBuiltInFallback    bool                  `json:"skipBuiltInFallback,omitempty"`    // If true, don't fallback to built-in providers (tidal/qobuz/amazon)
+	SkipBuiltInFallback    bool                   `json:"skipBuiltInFallback,omitempty"`
-	SearchBehavior         *SearchBehaviorConfig `json:"searchBehavior,omitempty"`         // Custom search behavior
+	SearchBehavior         *SearchBehaviorConfig  `json:"searchBehavior,omitempty"`
-	URLHandler             *URLHandlerConfig     `json:"urlHandler,omitempty"`             // Custom URL handling
+	URLHandler             *URLHandlerConfig      `json:"urlHandler,omitempty"`
-	TrackMatching          *TrackMatchingConfig  `json:"trackMatching,omitempty"`          // Custom track matching
+	TrackMatching          *TrackMatchingConfig   `json:"trackMatching,omitempty"`
-	PostProcessing         *PostProcessingConfig `json:"postProcessing,omitempty"`         // Post-processing hooks
+	PostProcessing         *PostProcessingConfig  `json:"postProcessing,omitempty"`
+	Capabilities           map[string]interface{} `json:"capabilities,omitempty"`
 }
 
-// ManifestValidationError represents a validation error in the manifest
 type ManifestValidationError struct {
 	Field   string
 	Message string
@@ -135,7 +132,6 @@ func (e *ManifestValidationError) Error() string {
 	return fmt.Sprintf("manifest validation error: %s - %s", e.Field, e.Message)
 }
 
-// ParseManifest parses and validates a manifest from JSON bytes
 func ParseManifest(data []byte) (*ExtensionManifest, error) {
 	var manifest ExtensionManifest
 	if err := json.Unmarshal(data, &manifest); err != nil {
@@ -149,9 +145,7 @@ func ParseManifest(data []byte) (*ExtensionManifest, error) {
 	return &manifest, nil
 }
 
-// Validate checks if the manifest has all required fields and valid values
 func (m *ExtensionManifest) Validate() error {
-	// Check required fields
 	if strings.TrimSpace(m.Name) == "" {
 		return &ManifestValidationError{Field: "name", Message: "name is required"}
 	}
@@ -172,7 +166,6 @@ func (m *ExtensionManifest) Validate() error {
 		return &ManifestValidationError{Field: "type", Message: "at least one type is required"}
 	}
 
-	// Validate extension types
 	for _, t := range m.Types {
 		if t != ExtensionTypeMetadataProvider && t != ExtensionTypeDownloadProvider {
 			return &ManifestValidationError{
@@ -198,20 +191,6 @@ func (m *ExtensionManifest) Validate() error {
 			}
 		}
 
-		// Validate setting type
-		validTypes := map[SettingType]bool{
-			SettingTypeString: true,
-			SettingTypeNumber: true,
-			SettingTypeBool:   true,
-			SettingTypeSelect: true,
-		}
-		if !validTypes[setting.Type] {
-			return &ManifestValidationError{
-				Field:   fmt.Sprintf("settings[%d].type", i),
-				Message: fmt.Sprintf("invalid setting type: %s", setting.Type),
-			}
-		}
-
 		// Select type requires options
 		if setting.Type == SettingTypeSelect && len(setting.Options) == 0 {
 			return &ManifestValidationError{
@@ -219,12 +198,18 @@ func (m *ExtensionManifest) Validate() error {
 				Message: "select type requires options",
 			}
 		}
+
+		if setting.Type == SettingTypeButton && setting.Action == "" {
+			return &ManifestValidationError{
+				Field:   fmt.Sprintf("settings[%d].action", i),
+				Message: "button type requires action (JS function name)",
+			}
+		}
 	}
 
 	return nil
 }
 
-// HasType checks if the extension has a specific type
 func (m *ExtensionManifest) HasType(t ExtensionType) bool {
 	for _, et := range m.Types {
 		if et == t {
@@ -234,17 +219,14 @@ func (m *ExtensionManifest) HasType(t ExtensionType) bool {
 	return false
 }
 
-// IsMetadataProvider returns true if extension provides metadata
 func (m *ExtensionManifest) IsMetadataProvider() bool {
 	return m.HasType(ExtensionTypeMetadataProvider)
 }
 
-// IsDownloadProvider returns true if extension provides downloads
 func (m *ExtensionManifest) IsDownloadProvider() bool {
 	return m.HasType(ExtensionTypeDownloadProvider)
 }
 
-// IsDomainAllowed checks if a domain is in the allowed network permissions
 func (m *ExtensionManifest) IsDomainAllowed(domain string) bool {
 	domain = strings.ToLower(strings.TrimSpace(domain))
 	for _, allowed := range m.Permissions.Network {
@@ -263,33 +245,27 @@ func (m *ExtensionManifest) IsDomainAllowed(domain string) bool {
 	return false
 }
 
-// HasCustomSearch returns true if extension provides custom search
 func (m *ExtensionManifest) HasCustomSearch() bool {
 	return m.SearchBehavior != nil && m.SearchBehavior.Enabled
 }
 
-// HasCustomMatching returns true if extension provides custom track matching
 func (m *ExtensionManifest) HasCustomMatching() bool {
 	return m.TrackMatching != nil && m.TrackMatching.CustomMatching
 }
 
-// HasPostProcessing returns true if extension provides post-processing
 func (m *ExtensionManifest) HasPostProcessing() bool {
 	return m.PostProcessing != nil && m.PostProcessing.Enabled
 }
 
-// HasURLHandler returns true if extension handles custom URLs
 func (m *ExtensionManifest) HasURLHandler() bool {
 	return m.URLHandler != nil && m.URLHandler.Enabled && len(m.URLHandler.Patterns) > 0
 }
 
-// MatchesURL checks if a URL matches any of the extension's URL patterns
 func (m *ExtensionManifest) MatchesURL(urlStr string) bool {
 	if !m.HasURLHandler() {
 		return false
 	}
 
-	// Parse URL to get host
 	urlStr = strings.ToLower(strings.TrimSpace(urlStr))
 	for _, pattern := range m.URLHandler.Patterns {
 		pattern = strings.ToLower(strings.TrimSpace(pattern))
@@ -301,7 +277,6 @@ func (m *ExtensionManifest) MatchesURL(urlStr string) bool {
 	return false
 }
 
-// GetPostProcessingHooks returns all post-processing hooks
 func (m *ExtensionManifest) GetPostProcessingHooks() []PostProcessingHook {
 	if m.PostProcessing == nil {
 		return nil
@@ -309,7 +284,6 @@ func (m *ExtensionManifest) GetPostProcessingHooks() []PostProcessingHook {
 	return m.PostProcessing.Hooks
 }
 
-// ToJSON serializes the manifest to JSON
 func (m *ExtensionManifest) ToJSON() ([]byte, error) {
 	return json.Marshal(m)
 }

go_backend/extension_providers.go

@@ -2,7 +2,9 @@
 package gobackend
 
 import (
+	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -29,6 +31,18 @@ type ExtTrackMetadata struct {
 	DiscNumber  int    `json:"disc_number,omitempty"`
 	ISRC        string `json:"isrc,omitempty"`
 	ProviderID  string `json:"provider_id"`
+	ItemType    string `json:"item_type,omitempty"`  // track, album, or playlist - for extension search results
+	AlbumType   string `json:"album_type,omitempty"` // album, single, ep, compilation
+	// Enrichment fields from Odesli/song.link
+	TidalID       string            `json:"tidal_id,omitempty"`
+	QobuzID       string            `json:"qobuz_id,omitempty"`
+	DeezerID      string            `json:"deezer_id,omitempty"`
+	SpotifyID     string            `json:"spotify_id,omitempty"`
+	ExternalLinks map[string]string `json:"external_links,omitempty"` // service -> URL mapping
+	// Extended metadata from enrichment (can come from Deezer, Spotify, etc.)
+	Label     string `json:"label,omitempty"`     // Record label
+	Copyright string `json:"copyright,omitempty"` // Copyright information
+	Genre     string `json:"genre,omitempty"`     // Music genre(s)
 }
 
 // ResolvedCoverURL returns the cover URL, checking both CoverURL and Images fields
@@ -44,6 +58,7 @@ type ExtAlbumMetadata struct {
 	ID          string             `json:"id"`
 	Name        string             `json:"name"`
 	Artists     string             `json:"artists"`
+	ArtistID    string             `json:"artist_id,omitempty"`
 	CoverURL    string             `json:"cover_url,omitempty"`
 	ReleaseDate string             `json:"release_date,omitempty"`
 	TotalTracks int                `json:"total_tracks"`
@@ -54,11 +69,14 @@ type ExtAlbumMetadata struct {
 
 // ExtArtistMetadata represents artist metadata from an extension
 type ExtArtistMetadata struct {
-	ID         string             `json:"id"`
+	ID          string             `json:"id"`
-	Name       string             `json:"name"`
+	Name        string             `json:"name"`
-	ImageURL   string             `json:"image_url,omitempty"`
+	ImageURL    string             `json:"image_url,omitempty"`
-	Albums     []ExtAlbumMetadata `json:"albums,omitempty"`
+	HeaderImage string             `json:"header_image,omitempty"` // Header image for artist page background
-	ProviderID string             `json:"provider_id"`
+	Listeners   int                `json:"listeners,omitempty"`    // Monthly listeners
+	Albums      []ExtAlbumMetadata `json:"albums,omitempty"`
+	TopTracks   []ExtTrackMetadata `json:"top_tracks,omitempty"` // Popular tracks
+	ProviderID  string             `json:"provider_id"`
 }
 
 // ExtSearchResult represents search results from an extension
@@ -132,6 +150,10 @@ func (p *ExtensionProviderWrapper) SearchTracks(query string, limit int) (*ExtSe
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	// Call extension's searchTracks function
 	script := fmt.Sprintf(`
 		(function() {
@@ -177,7 +199,6 @@ func (p *ExtensionProviderWrapper) SearchTracks(query string, limit int) (*ExtSe
 		}
 	}
 
-	// Set provider ID on all tracks
 	for i := range searchResult.Tracks {
 		searchResult.Tracks[i].ProviderID = p.extension.ID
 	}
@@ -195,6 +216,10 @@ func (p *ExtensionProviderWrapper) GetTrack(trackID string) (*ExtTrackMetadata,
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.getTrack === 'function') {
@@ -241,6 +266,10 @@ func (p *ExtensionProviderWrapper) GetAlbum(albumID string) (*ExtAlbumMetadata,
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.getAlbum === 'function') {
@@ -290,6 +319,10 @@ func (p *ExtensionProviderWrapper) GetArtist(artistID string) (*ExtArtistMetadat
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.getArtist === 'function') {
@@ -338,6 +371,10 @@ func (p *ExtensionProviderWrapper) EnrichTrack(track *ExtTrackMetadata) (*ExtTra
 		return track, nil // Extension disabled, return as-is
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	// Convert track to JSON for passing to JS
 	trackJSON, err := json.Marshal(track)
 	if err != nil {
@@ -404,6 +441,10 @@ func (p *ExtensionProviderWrapper) CheckAvailability(isrc, trackName, artistName
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.checkAvailability === 'function') {
@@ -449,6 +490,10 @@ func (p *ExtensionProviderWrapper) GetDownloadURL(trackID, quality string) (*Ext
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.getDownloadUrl === 'function') {
@@ -497,6 +542,10 @@ func (p *ExtensionProviderWrapper) Download(trackID, quality, outputPath string,
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	// Set up progress callback in VM
 	p.vm.Set("__onProgress", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) > 0 {
@@ -683,7 +732,7 @@ func GetMetadataProviderPriority() []string {
 // isBuiltInProvider checks if a provider ID is a built-in provider
 func isBuiltInProvider(providerID string) bool {
 	switch providerID {
-	case "tidal", "qobuz", "amazon":
+	case "tidal", "qobuz", "amazon", "deezer":
 		return true
 	default:
 		return false
@@ -699,6 +748,21 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 	priority := GetProviderPriority()
 	extManager := GetExtensionManager()
 
+	// If req.Service is a built-in provider, prioritize it first
+	// This handles user's explicit selection from the service picker
+	if req.Service != "" && isBuiltInProvider(req.Service) {
+		GoLog("[DownloadWithExtensionFallback] User selected service: %s, prioritizing it first\n", req.Service)
+		// Reorder priority to put req.Service first
+		newPriority := []string{req.Service}
+		for _, p := range priority {
+			if p != req.Service {
+				newPriority = append(newPriority, p)
+			}
+		}
+		priority = newPriority
+		GoLog("[DownloadWithExtensionFallback] New priority order: %v\n", priority)
+	}
+
 	var lastErr error
 	var skipBuiltIn bool // If source extension has skipBuiltInFallback, don't try built-in providers
 
@@ -725,18 +789,45 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 
 			enrichedTrack, err := provider.EnrichTrack(trackMeta)
 			if err == nil && enrichedTrack != nil {
-				// Update request with enriched data
 				if enrichedTrack.ISRC != "" && enrichedTrack.ISRC != req.ISRC {
 					GoLog("[DownloadWithExtensionFallback] ISRC enriched: %s -> %s\n", req.ISRC, enrichedTrack.ISRC)
 					req.ISRC = enrichedTrack.ISRC
 				}
-				// Can also update other fields if needed
+				if enrichedTrack.TidalID != "" {
+					GoLog("[DownloadWithExtensionFallback] Tidal ID from Odesli: %s\n", enrichedTrack.TidalID)
+					req.TidalID = enrichedTrack.TidalID
+				}
+				if enrichedTrack.QobuzID != "" {
+					GoLog("[DownloadWithExtensionFallback] Qobuz ID from Odesli: %s\n", enrichedTrack.QobuzID)
+					req.QobuzID = enrichedTrack.QobuzID
+				}
+				if enrichedTrack.DeezerID != "" {
+					GoLog("[DownloadWithExtensionFallback] Deezer ID from Odesli: %s\n", enrichedTrack.DeezerID)
+					req.DeezerID = enrichedTrack.DeezerID
+				}
 				if enrichedTrack.Name != "" {
 					req.TrackName = enrichedTrack.Name
 				}
 				if enrichedTrack.Artists != "" {
 					req.ArtistName = enrichedTrack.Artists
 				}
+				// Copy extended metadata from enrichment (label, copyright, genre, release_date)
+				if enrichedTrack.Label != "" && req.Label == "" {
+					GoLog("[DownloadWithExtensionFallback] Label from enrichment: %s\n", enrichedTrack.Label)
+					req.Label = enrichedTrack.Label
+				}
+				if enrichedTrack.Copyright != "" && req.Copyright == "" {
+					GoLog("[DownloadWithExtensionFallback] Copyright from enrichment: %s\n", enrichedTrack.Copyright)
+					req.Copyright = enrichedTrack.Copyright
+				}
+				if enrichedTrack.Genre != "" && req.Genre == "" {
+					GoLog("[DownloadWithExtensionFallback] Genre from enrichment: %s\n", enrichedTrack.Genre)
+					req.Genre = enrichedTrack.Genre
+				}
+				if enrichedTrack.ReleaseDate != "" && req.ReleaseDate == "" {
+					GoLog("[DownloadWithExtensionFallback] ReleaseDate from enrichment: %s\n", enrichedTrack.ReleaseDate)
+					req.ReleaseDate = enrichedTrack.ReleaseDate
+				}
 			}
 		}
 	}
@@ -747,7 +838,6 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 
 		ext, err := extManager.GetExtension(req.Source)
 		if err == nil && ext.Enabled && ext.Error == "" && ext.Manifest.IsDownloadProvider() {
-			// Check if this extension wants to skip built-in fallback
 			skipBuiltIn = ext.Manifest.SkipBuiltInFallback
 
 			provider := NewExtensionProviderWrapper(ext)
@@ -758,7 +848,6 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 
 			GoLog("[DownloadWithExtensionFallback] Downloading from source extension with trackID: %s (skipBuiltInFallback: %v)\n", trackID, skipBuiltIn)
 
-			// Build output path
 			outputPath := buildOutputPath(req)
 
 			// Download directly using the track ID from the extension
@@ -776,6 +865,18 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 					ActualBitDepth:   result.BitDepth,
 					ActualSampleRate: result.SampleRate,
 					Service:          req.Source,
+					Genre:            req.Genre,
+					Label:            req.Label,
+					Copyright:        req.Copyright,
+				}
+
+				// Embed genre and label if provided (from Deezer metadata)
+				if req.Genre != "" || req.Label != "" {
+					if err := EmbedGenreLabel(result.FilePath, req.Genre, req.Label); err != nil {
+						GoLog("[DownloadWithExtensionFallback] Warning: failed to embed genre/label: %v\n", err)
+					} else {
+						GoLog("[DownloadWithExtensionFallback] Embedded genre=%q label=%q\n", req.Genre, req.Label)
+					}
 				}
 
 				// If extension has skipMetadataEnrichment, copy metadata
@@ -814,6 +915,14 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 			}
 
 			if err != nil {
+				if errors.Is(err, ErrDownloadCancelled) {
+					return &DownloadResponse{
+						Success:   false,
+						Error:     "Download cancelled",
+						ErrorType: "cancelled",
+						Service:   req.Source,
+					}, nil
+				}
 				lastErr = err
 			} else if result.ErrorMessage != "" {
 				lastErr = fmt.Errorf("%s", result.ErrorMessage)
@@ -851,13 +960,55 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 		GoLog("[DownloadWithExtensionFallback] Trying provider: %s\n", providerID)
 
 		if isBuiltInProvider(providerID) {
+			// For built-in providers, enrich with Deezer metadata if not already present
+			if (req.Genre == "" || req.Label == "") && req.ISRC != "" {
+				GoLog("[DownloadWithExtensionFallback] Enriching extended metadata from Deezer for ISRC: %s\n", req.ISRC)
+				ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+				deezerClient := GetDeezerClient()
+				extMeta, err := deezerClient.GetExtendedMetadataByISRC(ctx, req.ISRC)
+				cancel()
+				if err == nil && extMeta != nil {
+					if req.Genre == "" && extMeta.Genre != "" {
+						req.Genre = extMeta.Genre
+						GoLog("[DownloadWithExtensionFallback] Genre from Deezer: %s\n", req.Genre)
+					}
+					if req.Label == "" && extMeta.Label != "" {
+						req.Label = extMeta.Label
+						GoLog("[DownloadWithExtensionFallback] Label from Deezer: %s\n", req.Label)
+					}
+				} else if err != nil {
+					GoLog("[DownloadWithExtensionFallback] Failed to get extended metadata from Deezer: %v\n", err)
+				}
+			}
+
 			// Use built-in provider
 			result, err := tryBuiltInProvider(providerID, req)
 			if err == nil && result.Success {
 				result.Service = providerID
+				// Copy enriched metadata to response for Flutter (needed for M4A->FLAC conversion)
+				if req.Label != "" {
+					result.Label = req.Label
+				}
+				if req.Copyright != "" {
+					result.Copyright = req.Copyright
+				}
+				if req.Genre != "" {
+					result.Genre = req.Genre
+				}
+				if req.ReleaseDate != "" && result.ReleaseDate == "" {
+					result.ReleaseDate = req.ReleaseDate
+				}
 				return result, nil
 			}
 			if err != nil {
+				if errors.Is(err, ErrDownloadCancelled) {
+					return &DownloadResponse{
+						Success:   false,
+						Error:     "Download cancelled",
+						ErrorType: "cancelled",
+						Service:   providerID,
+					}, nil
+				}
 				lastErr = err
 				GoLog("[DownloadWithExtensionFallback] %s failed: %v\n", providerID, err)
 			}
@@ -875,7 +1026,6 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 
 			provider := NewExtensionProviderWrapper(ext)
 
-			// Check availability first
 			availability, err := provider.CheckAvailability(req.ISRC, req.TrackName, req.ArtistName)
 			if err != nil || !availability.Available {
 				GoLog("[DownloadWithExtensionFallback] %s: not available\n", providerID)
@@ -885,12 +1035,9 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 				continue
 			}
 
-			// Build output path
 			outputPath := buildOutputPath(req)
 
-			// Download
 			result, err := provider.Download(availability.TrackID, req.Quality, outputPath, func(percent int) {
-				// Update progress
 				if req.ItemID != "" {
 					SetItemProgress(req.ItemID, float64(percent), 0, 0)
 				}
@@ -904,6 +1051,18 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 					ActualBitDepth:   result.BitDepth,
 					ActualSampleRate: result.SampleRate,
 					Service:          providerID,
+					Genre:            req.Genre,
+					Label:            req.Label,
+					Copyright:        req.Copyright,
+				}
+
+				// Embed genre and label if provided (from Deezer metadata)
+				if req.Genre != "" || req.Label != "" {
+					if err := EmbedGenreLabel(result.FilePath, req.Genre, req.Label); err != nil {
+						GoLog("[DownloadWithExtensionFallback] Warning: failed to embed genre/label: %v\n", err)
+					} else {
+						GoLog("[DownloadWithExtensionFallback] Embedded genre=%q label=%q\n", req.Genre, req.Label)
+					}
 				}
 
 				// If extension has skipMetadataEnrichment and returned metadata, use it
@@ -943,6 +1102,14 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 			}
 
 			if err != nil {
+				if errors.Is(err, ErrDownloadCancelled) {
+					return &DownloadResponse{
+						Success:   false,
+						Error:     "Download cancelled",
+						ErrorType: "cancelled",
+						Service:   providerID,
+					}, nil
+				}
 				lastErr = err
 			} else if result.ErrorMessage != "" {
 				lastErr = fmt.Errorf("%s", result.ErrorMessage)
@@ -1046,6 +1213,9 @@ func tryBuiltInProvider(providerID string, req DownloadRequest) (*DownloadRespon
 		TrackNumber:      result.TrackNumber,
 		DiscNumber:       result.DiscNumber,
 		ISRC:             result.ISRC,
+		Genre:            req.Genre,
+		Label:            req.Label,
+		Copyright:        req.Copyright,
 	}, nil
 }
 
@@ -1081,6 +1251,10 @@ func (p *ExtensionProviderWrapper) CustomSearch(query string, options map[string
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	// Convert options to JSON
 	optionsJSON, _ := json.Marshal(options)
 
@@ -1122,7 +1296,6 @@ func (p *ExtensionProviderWrapper) CustomSearch(query string, options map[string
 		tracks = []ExtTrackMetadata{}
 	}
 
-	// Set provider ID on all tracks
 	for i := range tracks {
 		tracks[i].ProviderID = p.extension.ID
 	}
@@ -1153,6 +1326,10 @@ func (p *ExtensionProviderWrapper) HandleURL(url string) (*ExtURLHandleResult, e
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	script := fmt.Sprintf(`
 		(function() {
 			if (typeof extension !== 'undefined' && typeof extension.handleUrl === 'function') {
@@ -1192,6 +1369,24 @@ func (p *ExtensionProviderWrapper) HandleURL(url string) (*ExtURLHandleResult, e
 	for i := range handleResult.Tracks {
 		handleResult.Tracks[i].ProviderID = p.extension.ID
 	}
+	if handleResult.Album != nil {
+		handleResult.Album.ProviderID = p.extension.ID
+		for i := range handleResult.Album.Tracks {
+			handleResult.Album.Tracks[i].ProviderID = p.extension.ID
+		}
+	}
+	if handleResult.Artist != nil {
+		handleResult.Artist.ProviderID = p.extension.ID
+		for i := range handleResult.Artist.Albums {
+			handleResult.Artist.Albums[i].ProviderID = p.extension.ID
+			for j := range handleResult.Artist.Albums[i].Tracks {
+				handleResult.Artist.Albums[i].Tracks[j].ProviderID = p.extension.ID
+			}
+		}
+		for i := range handleResult.Artist.TopTracks {
+			handleResult.Artist.TopTracks[i].ProviderID = p.extension.ID
+		}
+	}
 
 	return &handleResult, nil
 }
@@ -1216,6 +1411,10 @@ func (p *ExtensionProviderWrapper) MatchTrack(sourceTrack map[string]interface{}
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	sourceJSON, _ := json.Marshal(sourceTrack)
 	candidatesJSON, _ := json.Marshal(candidates)
 
@@ -1279,6 +1478,10 @@ func (p *ExtensionProviderWrapper) PostProcess(filePath string, metadata map[str
 		return nil, fmt.Errorf("extension '%s' is disabled", p.extension.ID)
 	}
 
+	// Lock VM to prevent concurrent access
+	p.extension.VMMu.Lock()
+	defer p.extension.VMMu.Unlock()
+
 	metadataJSON, _ := json.Marshal(metadata)
 
 	script := fmt.Sprintf(`
@@ -1425,12 +1628,10 @@ func (m *ExtensionManager) RunPostProcessing(filePath string, metadata map[strin
 	for _, provider := range providers {
 		hooks := provider.extension.Manifest.GetPostProcessingHooks()
 		for _, hook := range hooks {
-			// Check if hook is enabled (TODO: check user settings)
 			if !hook.DefaultEnabled {
 				continue
 			}
 
-			// Check if format is supported
 			ext := strings.ToLower(filepath.Ext(currentPath))
 			if len(hook.SupportedFormats) > 0 {
 				supported := false

go_backend/extension_runtime.go

@@ -1,4 +1,3 @@
-// Package gobackend provides extension runtime with sandboxed execution
 package gobackend
 
 import (
@@ -10,16 +9,13 @@ import (
 	"github.com/dop251/goja"
 )
 
-// Default timeout for JS execution (30 seconds)
 const DefaultJSTimeout = 30 * time.Second
 
-// Global auth state for extensions (stores pending auth codes)
 var (
 	extensionAuthState   = make(map[string]*ExtensionAuthState)
 	extensionAuthStateMu sync.RWMutex
 )
 
-// ExtensionAuthState holds auth state for an extension
 type ExtensionAuthState struct {
 	PendingAuthURL  string
 	AuthCode        string
@@ -27,39 +23,33 @@ type ExtensionAuthState struct {
 	RefreshToken    string
 	ExpiresAt       time.Time
 	IsAuthenticated bool
-	// PKCE support
+	PKCEVerifier    string
-	PKCEVerifier  string
+	PKCEChallenge   string
-	PKCEChallenge string
 }
 
-// PendingAuthRequest holds a pending OAuth request that needs Flutter to open URL
 type PendingAuthRequest struct {
 	ExtensionID string
 	AuthURL     string
 	CallbackURL string
 }
 
-// Global pending auth requests (Flutter polls this)
 var (
 	pendingAuthRequests   = make(map[string]*PendingAuthRequest)
 	pendingAuthRequestsMu sync.RWMutex
 )
 
-// GetPendingAuthRequest returns pending auth request for an extension (called from Flutter)
 func GetPendingAuthRequest(extensionID string) *PendingAuthRequest {
 	pendingAuthRequestsMu.RLock()
 	defer pendingAuthRequestsMu.RUnlock()
 	return pendingAuthRequests[extensionID]
 }
 
-// ClearPendingAuthRequest clears pending auth request (called from Flutter after opening URL)
 func ClearPendingAuthRequest(extensionID string) {
 	pendingAuthRequestsMu.Lock()
 	defer pendingAuthRequestsMu.Unlock()
 	delete(pendingAuthRequests, extensionID)
 }
 
-// SetExtensionAuthCode sets auth code for an extension (called from Flutter after OAuth callback)
 func SetExtensionAuthCode(extensionID string, authCode string) {
 	extensionAuthStateMu.Lock()
 	defer extensionAuthStateMu.Unlock()
@@ -72,7 +62,6 @@ func SetExtensionAuthCode(extensionID string, authCode string) {
 	state.AuthCode = authCode
 }
 
-// SetExtensionTokens sets access/refresh tokens for an extension
 func SetExtensionTokens(extensionID string, accessToken, refreshToken string, expiresAt time.Time) {
 	extensionAuthStateMu.Lock()
 	defer extensionAuthStateMu.Unlock()
@@ -88,7 +77,6 @@ func SetExtensionTokens(extensionID string, accessToken, refreshToken string, ex
 	state.IsAuthenticated = accessToken != ""
 }
 
-// ExtensionRuntime provides sandboxed APIs for extensions
 type ExtensionRuntime struct {
 	extensionID string
 	manifest    *ExtensionManifest
@@ -99,9 +87,7 @@ type ExtensionRuntime struct {
 	vm          *goja.Runtime
 }
 
-// NewExtensionRuntime creates a new runtime for an extension
 func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
-	// Create a cookie jar for this extension
 	jar, _ := newSimpleCookieJar()
 
 	runtime := &ExtensionRuntime{
@@ -113,7 +99,6 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 		vm:          ext.VM,
 	}
 
-	// Create HTTP client with redirect validation to prevent SSRF via open redirect
 	client := &http.Client{
 		Timeout: 30 * time.Second,
 		Jar:     jar,
@@ -124,7 +109,6 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 				GoLog("[Extension:%s] Redirect blocked: domain '%s' not in allowed list\n", ext.ID, domain)
 				return &RedirectBlockedError{Domain: domain}
 			}
-			// Also block redirects to private/local networks (SSRF protection)
 			if isPrivateIP(domain) {
 				GoLog("[Extension:%s] Redirect blocked: private IP '%s'\n", ext.ID, domain)
 				return &RedirectBlockedError{Domain: domain, IsPrivate: true}
@@ -141,7 +125,6 @@ func NewExtensionRuntime(ext *LoadedExtension) *ExtensionRuntime {
 	return runtime
 }
 
-// RedirectBlockedError is returned when a redirect is blocked due to domain validation
 type RedirectBlockedError struct {
 	Domain    string
 	IsPrivate bool
@@ -167,10 +150,10 @@ func isPrivateIP(host string) bool {
 		"172.24.", "172.25.", "172.26.", "172.27.",
 		"172.28.", "172.29.", "172.30.", "172.31.",
 		"192.168.",
-		"169.254.", // Link-local
+		"169.254.",
-		"::1",      // IPv6 localhost
+		"::1",
-		"fc00:",    // IPv6 private
+		"fc00:",
-		"fe80:",    // IPv6 link-local
+		"fe80:",
 	}
 
 	hostLower := host
@@ -188,7 +171,6 @@ func isPrivateIP(host string) bool {
 	return false
 }
 
-// simpleCookieJar is a simple in-memory cookie jar
 type simpleCookieJar struct {
 	cookies map[string][]*http.Cookie
 	mu      sync.RWMutex
@@ -213,12 +195,10 @@ func (j *simpleCookieJar) Cookies(u *url.URL) []*http.Cookie {
 	return j.cookies[u.Host]
 }
 
-// SetSettings updates the runtime settings
 func (r *ExtensionRuntime) SetSettings(settings map[string]interface{}) {
 	r.settings = settings
 }
 
-// RegisterAPIs registers all sandboxed APIs to the Goja VM
 func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	r.vm = vm
 
@@ -229,18 +209,16 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	httpObj.Set("put", r.httpPut)
 	httpObj.Set("delete", r.httpDelete)
 	httpObj.Set("patch", r.httpPatch)
-	httpObj.Set("request", r.httpRequest) // Generic HTTP request (GET, POST, PUT, DELETE, etc.)
+	httpObj.Set("request", r.httpRequest)
 	httpObj.Set("clearCookies", r.httpClearCookies)
 	vm.Set("http", httpObj)
 
-	// Storage API
 	storageObj := vm.NewObject()
 	storageObj.Set("get", r.storageGet)
 	storageObj.Set("set", r.storageSet)
 	storageObj.Set("remove", r.storageRemove)
 	vm.Set("storage", storageObj)
 
-	// Secure Credentials API (encrypted storage for sensitive data)
 	credentialsObj := vm.NewObject()
 	credentialsObj.Set("store", r.credentialsStore)
 	credentialsObj.Set("get", r.credentialsGet)
@@ -248,7 +226,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	credentialsObj.Set("has", r.credentialsHas)
 	vm.Set("credentials", credentialsObj)
 
-	// Auth API (for OAuth and other auth flows)
 	authObj := vm.NewObject()
 	authObj.Set("openAuthUrl", r.authOpenUrl)
 	authObj.Set("getAuthCode", r.authGetCode)
@@ -256,7 +233,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	authObj.Set("clearAuth", r.authClear)
 	authObj.Set("isAuthenticated", r.authIsAuthenticated)
 	authObj.Set("getTokens", r.authGetTokens)
-	// PKCE support
 	authObj.Set("generatePKCE", r.authGeneratePKCE)
 	authObj.Set("getPKCE", r.authGetPKCE)
 	authObj.Set("startOAuthWithPKCE", r.authStartOAuthWithPKCE)
@@ -275,7 +251,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	fileObj.Set("getSize", r.fileGetSize)
 	vm.Set("file", fileObj)
 
-	// FFmpeg API (for post-processing)
 	ffmpegObj := vm.NewObject()
 	ffmpegObj.Set("execute", r.ffmpegExecute)
 	ffmpegObj.Set("getInfo", r.ffmpegGetInfo)
@@ -289,7 +264,6 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	matchingObj.Set("normalizeString", r.matchingNormalizeString)
 	vm.Set("matching", matchingObj)
 
-	// Utilities
 	utilsObj := vm.NewObject()
 	utilsObj.Set("base64Encode", r.base64Encode)
 	utilsObj.Set("base64Decode", r.base64Decode)
@@ -300,13 +274,12 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	utilsObj.Set("hmacSHA1", r.hmacSHA1)
 	utilsObj.Set("parseJSON", r.parseJSON)
 	utilsObj.Set("stringifyJSON", r.stringifyJSON)
-	// Crypto utilities for developers
 	utilsObj.Set("encrypt", r.cryptoEncrypt)
 	utilsObj.Set("decrypt", r.cryptoDecrypt)
 	utilsObj.Set("generateKey", r.cryptoGenerateKey)
+	utilsObj.Set("randomUserAgent", r.randomUserAgent)
 	vm.Set("utils", utilsObj)
 
-	// Log object (already set in extension_manager.go, but we can enhance it)
 	logObj := vm.NewObject()
 	logObj.Set("debug", r.logDebug)
 	logObj.Set("info", r.logInfo)
@@ -314,27 +287,18 @@ func (r *ExtensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	logObj.Set("error", r.logError)
 	vm.Set("log", logObj)
 
-	// Go backend functions
 	gobackendObj := vm.NewObject()
 	gobackendObj.Set("sanitizeFilename", r.sanitizeFilenameWrapper)
 	vm.Set("gobackend", gobackendObj)
 
-	// ==================== Browser-like Polyfills ====================
-	// These make porting browser/Node.js libraries easier
-
-	// Global fetch() - Promise-style HTTP API (browser-compatible)
 	vm.Set("fetch", r.fetchPolyfill)
 
-	// Global atob/btoa - Base64 encoding (browser-compatible)
 	vm.Set("atob", r.atobPolyfill)
 	vm.Set("btoa", r.btoaPolyfill)
 
-	// TextEncoder/TextDecoder constructors
 	r.registerTextEncoderDecoder(vm)
 
-	// URL class for URL parsing
 	r.registerURLClass(vm)
 
-	// JSON global (browser-compatible)
 	r.registerJSONGlobal(vm)
 }

go_backend/extension_runtime_auth.go

@@ -18,7 +18,6 @@ import (
 
 // ==================== Auth API (OAuth Support) ====================
 
-// authOpenUrl requests Flutter to open an OAuth URL
 func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -33,7 +32,6 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 		callbackURL = call.Arguments[1].String()
 	}
 
-	// Store pending auth request for Flutter to pick up
 	pendingAuthRequestsMu.Lock()
 	pendingAuthRequests[r.extensionID] = &PendingAuthRequest{
 		ExtensionID: r.extensionID,
@@ -42,7 +40,6 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	}
 	pendingAuthRequestsMu.Unlock()
 
-	// Update auth state
 	extensionAuthStateMu.Lock()
 	state, exists := extensionAuthState[r.extensionID]
 	if !exists {
@@ -50,7 +47,7 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 		extensionAuthState[r.extensionID] = state
 	}
 	state.PendingAuthURL = authURL
-	state.AuthCode = "" // Clear any previous auth code
+	state.AuthCode = ""
 	extensionAuthStateMu.Unlock()
 
 	GoLog("[Extension:%s] Auth URL requested: %s\n", r.extensionID, authURL)
@@ -61,7 +58,6 @@ func (r *ExtensionRuntime) authOpenUrl(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// authGetCode gets the auth code (set by Flutter after OAuth callback)
 func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
@@ -74,13 +70,11 @@ func (r *ExtensionRuntime) authGetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(state.AuthCode)
 }
 
-// authSetCode sets auth code and tokens (can be called by extension after token exchange)
 func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
 	}
 
-	// Can accept either just auth code or an object with tokens
 	arg := call.Arguments[0].Export()
 
 	extensionAuthStateMu.Lock()
@@ -114,7 +108,6 @@ func (r *ExtensionRuntime) authSetCode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-// authClear clears all auth state for the extension
 func (r *ExtensionRuntime) authClear(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.Lock()
 	delete(extensionAuthState, r.extensionID)
@@ -138,7 +131,6 @@ func (r *ExtensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Valu
 		return r.vm.ToValue(false)
 	}
 
-	// Check if token is expired
 	if state.IsAuthenticated && !state.ExpiresAt.IsZero() && time.Now().After(state.ExpiresAt) {
 		return r.vm.ToValue(false)
 	}
@@ -146,7 +138,6 @@ func (r *ExtensionRuntime) authIsAuthenticated(call goja.FunctionCall) goja.Valu
 	return r.vm.ToValue(state.IsAuthenticated)
 }
 
-// authGetTokens returns current tokens (for extension to use in API calls)
 func (r *ExtensionRuntime) authGetTokens(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
@@ -182,16 +173,13 @@ func generatePKCEVerifier(length int) (string, error) {
 		length = 128
 	}
 
-	// Generate random bytes
 	bytes := make([]byte, length)
 	if _, err := rand.Read(bytes); err != nil {
 		return "", err
 	}
 
-	// Use base64url encoding without padding (RFC 7636 compliant)
 	verifier := base64.RawURLEncoding.EncodeToString(bytes)
 
-	// Trim to exact length
 	if len(verifier) > length {
 		verifier = verifier[:length]
 	}
@@ -199,15 +187,12 @@ func generatePKCEVerifier(length int) (string, error) {
 	return verifier, nil
 }
 
-// generatePKCEChallenge generates a code challenge from verifier using S256 method
 func generatePKCEChallenge(verifier string) string {
 	hash := sha256.Sum256([]byte(verifier))
 	// Base64url encode without padding (RFC 7636)
 	return base64.RawURLEncoding.EncodeToString(hash[:])
 }
 
-// authGeneratePKCE generates a PKCE code verifier and challenge pair
-// Returns: { verifier: string, challenge: string, method: "S256" }
 func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	// Default length is 64 characters
 	length := 64
@@ -227,7 +212,6 @@ func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 
 	challenge := generatePKCEChallenge(verifier)
 
-	// Store in auth state for later use
 	extensionAuthStateMu.Lock()
 	state, exists := extensionAuthState[r.extensionID]
 	if !exists {
@@ -247,7 +231,6 @@ func (r *ExtensionRuntime) authGeneratePKCE(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// authGetPKCE returns the current PKCE verifier and challenge (if generated)
 func (r *ExtensionRuntime) authGetPKCE(call goja.FunctionCall) goja.Value {
 	extensionAuthStateMu.RLock()
 	defer extensionAuthStateMu.RUnlock()
@@ -405,7 +388,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Get stored PKCE verifier
 	extensionAuthStateMu.RLock()
 	state, exists := extensionAuthState[r.extensionID]
 	var verifier string
@@ -421,7 +403,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Validate domain
 	if err := r.validateDomain(tokenURL); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -429,7 +410,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Build token request body
 	formData := url.Values{}
 	formData.Set("grant_type", "authorization_code")
 	formData.Set("client_id", clientID)
@@ -439,14 +419,12 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		formData.Set("redirect_uri", redirectURI)
 	}
 
-	// Add extra params
 	if extraParams, ok := config["extraParams"].(map[string]interface{}); ok {
 		for k, v := range extraParams {
 			formData.Set(k, fmt.Sprintf("%v", v))
 		}
 	}
 
-	// Make token request
 	req, err := http.NewRequest("POST", tokenURL, strings.NewReader(formData.Encode()))
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -475,7 +453,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Parse response
 	var tokenResp map[string]interface{}
 	if err := json.Unmarshal(body, &tokenResp); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -485,7 +462,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Check for error in response
 	if errMsg, ok := tokenResp["error"].(string); ok {
 		errDesc, _ := tokenResp["error_description"].(string)
 		return r.vm.ToValue(map[string]interface{}{
@@ -495,7 +471,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Extract tokens
 	accessToken, _ := tokenResp["access_token"].(string)
 	refreshToken, _ := tokenResp["refresh_token"].(string)
 	expiresIn, _ := tokenResp["expires_in"].(float64)
@@ -508,7 +483,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 		})
 	}
 
-	// Store tokens in auth state
 	extensionAuthStateMu.Lock()
 	state, exists = extensionAuthState[r.extensionID]
 	if !exists {
@@ -521,14 +495,12 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 	if expiresIn > 0 {
 		state.ExpiresAt = time.Now().Add(time.Duration(expiresIn) * time.Second)
 	}
-	// Clear PKCE after successful exchange
 	state.PKCEVerifier = ""
 	state.PKCEChallenge = ""
 	extensionAuthStateMu.Unlock()
 
 	GoLog("[Extension:%s] PKCE token exchange successful\n", r.extensionID)
 
-	// Return full token response
 	result := map[string]interface{}{
 		"success":       true,
 		"access_token":  accessToken,
@@ -538,7 +510,6 @@ func (r *ExtensionRuntime) authExchangeCodeWithPKCE(call goja.FunctionCall) goja
 	if expiresIn > 0 {
 		result["expires_in"] = expiresIn
 	}
-	// Include any additional fields from response
 	if scope, ok := tokenResp["scope"].(string); ok {
 		result["scope"] = scope
 	}

go_backend/extension_runtime_ffmpeg.go

@@ -31,14 +31,12 @@ var (
 	ffmpegCommandID  int64
 )
 
-// GetPendingFFmpegCommand returns a pending FFmpeg command (called from Flutter)
 func GetPendingFFmpegCommand(commandID string) *FFmpegCommand {
 	ffmpegCommandsMu.RLock()
 	defer ffmpegCommandsMu.RUnlock()
 	return ffmpegCommands[commandID]
 }
 
-// SetFFmpegCommandResult sets the result of an FFmpeg command (called from Flutter)
 func SetFFmpegCommandResult(commandID string, success bool, output, errorMsg string) {
 	ffmpegCommandsMu.Lock()
 	defer ffmpegCommandsMu.Unlock()
@@ -50,14 +48,12 @@ func SetFFmpegCommandResult(commandID string, success bool, output, errorMsg str
 	}
 }
 
-// ClearFFmpegCommand removes a completed FFmpeg command
 func ClearFFmpegCommand(commandID string) {
 	ffmpegCommandsMu.Lock()
 	defer ffmpegCommandsMu.Unlock()
 	delete(ffmpegCommands, commandID)
 }
 
-// ffmpegExecute queues an FFmpeg command for execution by Flutter
 func (r *ExtensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -118,7 +114,6 @@ func (r *ExtensionRuntime) ffmpegExecute(call goja.FunctionCall) goja.Value {
 	}
 }
 
-// ffmpegGetInfo gets audio file information using FFprobe
 func (r *ExtensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -147,7 +142,6 @@ func (r *ExtensionRuntime) ffmpegGetInfo(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// ffmpegConvert is a helper for common conversion operations
 func (r *ExtensionRuntime) ffmpegConvert(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{

go_backend/extension_runtime_file.go

@@ -15,14 +15,11 @@ import (
 
 // ==================== File API (Sandboxed) ====================
 
-// List of allowed directories for file operations (set by Go backend for download operations)
 var (
 	allowedDownloadDirs   []string
 	allowedDownloadDirsMu sync.RWMutex
 )
 
-// SetAllowedDownloadDirs sets the list of directories where extensions can write files
-// This should be called by the Go backend when setting up download paths
 func SetAllowedDownloadDirs(dirs []string) {
 	allowedDownloadDirsMu.Lock()
 	defer allowedDownloadDirsMu.Unlock()
@@ -30,7 +27,6 @@ func SetAllowedDownloadDirs(dirs []string) {
 	GoLog("[Extension] Allowed download directories set: %v\n", dirs)
 }
 
-// AddAllowedDownloadDir adds a directory to the allowed list
 func AddAllowedDownloadDir(dir string) {
 	allowedDownloadDirsMu.Lock()
 	defer allowedDownloadDirsMu.Unlock()
@@ -40,7 +36,6 @@ func AddAllowedDownloadDir(dir string) {
 	}
 }
 
-// isPathInAllowedDirs checks if an absolute path is within any allowed directory
 func isPathInAllowedDirs(absPath string) bool {
 	allowedDownloadDirsMu.RLock()
 	defer allowedDownloadDirsMu.RUnlock()
@@ -53,45 +48,34 @@ func isPathInAllowedDirs(absPath string) bool {
 	return false
 }
 
-// validatePath checks if the path is within the extension's sandbox
-// Security: Absolute paths are BLOCKED unless they're in allowed download directories
-// Extensions should use relative paths for their own data storage
 func (r *ExtensionRuntime) validatePath(path string) (string, error) {
 	// Check if extension has file permission
 	if !r.manifest.Permissions.File {
 		return "", fmt.Errorf("file access denied: extension does not have 'file' permission")
 	}
 
-	// Clean and resolve the path
 	cleanPath := filepath.Clean(path)
 
-	// SECURITY: Block absolute paths by default
-	// Only allow if path is in explicitly allowed download directories
 	if filepath.IsAbs(cleanPath) {
 		absPath, err := filepath.Abs(cleanPath)
 		if err != nil {
 			return "", fmt.Errorf("invalid path: %w", err)
 		}
 
-		// Check if path is in allowed download directories
 		if isPathInAllowedDirs(absPath) {
 			return absPath, nil
 		}
 
-		// Block all other absolute paths
 		return "", fmt.Errorf("file access denied: absolute paths are not allowed. Use relative paths within extension sandbox")
 	}
 
-	// For relative paths, join with data directory (extension's sandbox)
 	fullPath := filepath.Join(r.dataDir, cleanPath)
 
-	// Resolve to absolute path
 	absPath, err := filepath.Abs(fullPath)
 	if err != nil {
 		return "", fmt.Errorf("invalid path: %w", err)
 	}
 
-	// Ensure path is within data directory (prevent path traversal)
 	absDataDir, _ := filepath.Abs(r.dataDir)
 	if !strings.HasPrefix(absPath, absDataDir) {
 		return "", fmt.Errorf("file access denied: path '%s' is outside sandbox", path)
@@ -100,8 +84,6 @@ func (r *ExtensionRuntime) validatePath(path string) (string, error) {
 	return absPath, nil
 }
 
-// fileDownload downloads a file from URL to the specified path
-// Supports progress callback via options.onProgress
 func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -113,7 +95,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	urlStr := call.Arguments[0].String()
 	outputPath := call.Arguments[1].String()
 
-	// Validate domain
 	if err := r.validateDomain(urlStr); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -121,7 +102,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Validate output path (allows absolute paths for download queue)
 	fullPath, err := r.validatePath(outputPath)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -130,20 +110,17 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Get options if provided
 	var onProgress goja.Callable
 	var headers map[string]string
 	if len(call.Arguments) > 2 && !goja.IsUndefined(call.Arguments[2]) && !goja.IsNull(call.Arguments[2]) {
 		optionsObj := call.Arguments[2].Export()
 		if opts, ok := optionsObj.(map[string]interface{}); ok {
-			// Extract headers
 			if h, ok := opts["headers"].(map[string]interface{}); ok {
 				headers = make(map[string]string)
 				for k, v := range h {
 					headers[k] = fmt.Sprintf("%v", v)
 				}
 			}
-			// Extract onProgress callback
 			if progressVal, ok := opts["onProgress"]; ok {
 				if callable, ok := goja.AssertFunction(r.vm.ToValue(progressVal)); ok {
 					onProgress = callable
@@ -152,7 +129,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		}
 	}
 
-	// Create directory if needed
 	dir := filepath.Dir(fullPath)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -161,7 +137,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Create HTTP request
 	req, err := http.NewRequest("GET", urlStr, nil)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -170,7 +145,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
@@ -178,7 +152,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		req.Header.Set("User-Agent", "SpotiFLAC-Extension/1.0")
 	}
 
-	// Download file
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -195,7 +168,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Create output file
 	out, err := os.Create(fullPath)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -205,12 +177,10 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	}
 	defer out.Close()
 
-	// Get content length for progress
 	contentLength := resp.ContentLength
 
-	// Copy content with progress reporting
 	var written int64
-	buf := make([]byte, 32*1024) // 32KB buffer
+	buf := make([]byte, 32*1024)
 	for {
 		nr, er := resp.Body.Read(buf)
 		if nr > 0 {
@@ -235,7 +205,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 				})
 			}
 
-			// Report progress
 			if onProgress != nil && contentLength > 0 {
 				_, _ = onProgress(goja.Undefined(), r.vm.ToValue(written), r.vm.ToValue(contentLength))
 			}
@@ -260,7 +229,6 @@ func (r *ExtensionRuntime) fileDownload(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileExists checks if a file exists in the sandbox
 func (r *ExtensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -276,7 +244,6 @@ func (r *ExtensionRuntime) fileExists(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(err == nil)
 }
 
-// fileDelete deletes a file in the sandbox
 func (r *ExtensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -306,7 +273,6 @@ func (r *ExtensionRuntime) fileDelete(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileRead reads a file from the sandbox
 func (r *ExtensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -338,7 +304,6 @@ func (r *ExtensionRuntime) fileRead(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileWrite writes data to a file in the sandbox
 func (r *ExtensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -380,7 +345,6 @@ func (r *ExtensionRuntime) fileWrite(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileCopy copies a file within the sandbox
 func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -408,7 +372,6 @@ func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Read source file
 	data, err := os.ReadFile(fullSrc)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -417,7 +380,6 @@ func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Create destination directory if needed
 	dir := filepath.Dir(fullDst)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -426,7 +388,6 @@ func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Write to destination
 	if err := os.WriteFile(fullDst, data, 0644); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
@@ -440,7 +401,6 @@ func (r *ExtensionRuntime) fileCopy(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileMove moves/renames a file within the sandbox
 func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -468,7 +428,6 @@ func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Create destination directory if needed
 	dir := filepath.Dir(fullDst)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -490,7 +449,6 @@ func (r *ExtensionRuntime) fileMove(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// fileGetSize returns the size of a file in bytes
 func (r *ExtensionRuntime) fileGetSize(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{

go_backend/extension_runtime_http.go

@@ -14,14 +14,12 @@ import (
 
 // ==================== HTTP API (Sandboxed) ====================
 
-// HTTPResponse represents the response from an HTTP request
 type HTTPResponse struct {
 	StatusCode int               `json:"statusCode"`
 	Body       string            `json:"body"`
 	Headers    map[string]string `json:"headers"`
 }
 
-// validateDomain checks if the domain is allowed by the extension's permissions
 func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	parsed, err := url.Parse(urlStr)
 	if err != nil {
@@ -42,7 +40,6 @@ func (r *ExtensionRuntime) validateDomain(urlStr string) error {
 	return nil
 }
 
-// httpGet performs a GET request (sandboxed)
 func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -52,7 +49,6 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 
 	urlStr := call.Arguments[0].String()
 
-	// Validate domain
 	if err := r.validateDomain(urlStr); err != nil {
 		GoLog("[Extension:%s] HTTP blocked: %v\n", r.extensionID, err)
 		return r.vm.ToValue(map[string]interface{}{
@@ -60,7 +56,6 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Get headers if provided
 	headers := make(map[string]string)
 	if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 		headersObj := call.Arguments[1].Export()
@@ -71,7 +66,6 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		}
 	}
 
-	// Create request
 	req, err := http.NewRequest("GET", urlStr, nil)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -79,16 +73,14 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set default User-Agent if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -97,7 +89,6 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	// Read body
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -105,26 +96,24 @@ func (r *ExtensionRuntime) httpGet(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers (cookies, etc.)
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-// httpPost performs a POST request (sandboxed)
 func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -134,7 +123,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 
 	urlStr := call.Arguments[0].String()
 
-	// Validate domain
 	if err := r.validateDomain(urlStr); err != nil {
 		GoLog("[Extension:%s] HTTP blocked: %v\n", r.extensionID, err)
 		return r.vm.ToValue(map[string]interface{}{
@@ -142,7 +130,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Get body if provided - support both string and object
 	var bodyStr string
 	if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 		bodyArg := call.Arguments[1].Export()
@@ -150,7 +137,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		case string:
 			bodyStr = v
 		case map[string]interface{}, []interface{}:
-			// Auto-stringify objects and arrays to JSON
 			jsonBytes, err := json.Marshal(v)
 			if err != nil {
 				return r.vm.ToValue(map[string]interface{}{
@@ -159,12 +145,10 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 			}
 			bodyStr = string(jsonBytes)
 		default:
-			// Fallback to string conversion
 			bodyStr = call.Arguments[1].String()
 		}
 	}
 
-	// Get headers if provided
 	headers := make(map[string]string)
 	if len(call.Arguments) > 2 && !goja.IsUndefined(call.Arguments[2]) && !goja.IsNull(call.Arguments[2]) {
 		headersObj := call.Arguments[2].Export()
@@ -175,7 +159,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		}
 	}
 
-	// Create request
 	req, err := http.NewRequest("POST", urlStr, strings.NewReader(bodyStr))
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -183,11 +166,10 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set defaults if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
@@ -195,7 +177,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -204,7 +185,6 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	// Read body
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -212,27 +192,24 @@ func (r *ExtensionRuntime) httpPost(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-// httpRequest performs a generic HTTP request (GET, POST, PUT, DELETE, etc.)
-// Usage: http.request(url, options) where options = { method, body, headers }
 func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -242,7 +219,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 
 	urlStr := call.Arguments[0].String()
 
-	// Validate domain
 	if err := r.validateDomain(urlStr); err != nil {
 		GoLog("[Extension:%s] HTTP blocked: %v\n", r.extensionID, err)
 		return r.vm.ToValue(map[string]interface{}{
@@ -250,27 +226,22 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Default options
 	method := "GET"
 	var bodyStr string
 	headers := make(map[string]string)
 
-	// Parse options if provided
 	if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 		optionsObj := call.Arguments[1].Export()
 		if opts, ok := optionsObj.(map[string]interface{}); ok {
-			// Get method
 			if m, ok := opts["method"].(string); ok {
 				method = strings.ToUpper(m)
 			}
 
-			// Get body - support both string and object
 			if bodyArg, ok := opts["body"]; ok && bodyArg != nil {
 				switch v := bodyArg.(type) {
 				case string:
 					bodyStr = v
 				case map[string]interface{}, []interface{}:
-					// Auto-stringify objects and arrays to JSON
 					jsonBytes, err := json.Marshal(v)
 					if err != nil {
 						return r.vm.ToValue(map[string]interface{}{
@@ -283,7 +254,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 				}
 			}
 
-			// Get headers
 			if h, ok := opts["headers"].(map[string]interface{}); ok {
 				for k, v := range h {
 					headers[k] = fmt.Sprintf("%v", v)
@@ -292,7 +262,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		}
 	}
 
-	// Create request
 	var reqBody io.Reader
 	if bodyStr != "" {
 		reqBody = strings.NewReader(bodyStr)
@@ -305,11 +274,10 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
-	// Only set defaults if not provided by extension
+
 	if req.Header.Get("User-Agent") == "" {
 		req.Header.Set("User-Agent", "Spotiflac-Extension/1.0")
 	}
@@ -317,7 +285,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -326,7 +293,6 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 	}
 	defer resp.Body.Close()
 
-	// Read body
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -334,43 +300,36 @@ func (r *ExtensionRuntime) httpRequest(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Extract response headers - return all values as arrays for multi-value headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
 			respHeaders[k] = v[0]
 		} else {
-			respHeaders[k] = v // Return as array if multiple values
+			respHeaders[k] = v
 		}
 	}
 
-	// Return response with helper properties
 	return r.vm.ToValue(map[string]interface{}{
 		"statusCode": resp.StatusCode,
-		"status":     resp.StatusCode, // Alias for convenience
+		"status":     resp.StatusCode,
 		"ok":         resp.StatusCode >= 200 && resp.StatusCode < 300,
 		"body":       string(body),
 		"headers":    respHeaders,
 	})
 }
 
-// httpPut performs a PUT request (shortcut for http.request with method: "PUT")
 func (r *ExtensionRuntime) httpPut(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PUT", call)
 }
 
-// httpDelete performs a DELETE request (shortcut for http.request with method: "DELETE")
 func (r *ExtensionRuntime) httpDelete(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("DELETE", call)
 }
 
-// httpPatch performs a PATCH request (shortcut for http.request with method: "PATCH")
 func (r *ExtensionRuntime) httpPatch(call goja.FunctionCall) goja.Value {
 	return r.httpMethodShortcut("PATCH", call)
 }
 
-// httpMethodShortcut is a helper for PUT/DELETE/PATCH shortcuts
-// Signature: http.put(url, body, headers) / http.delete(url, headers) / http.patch(url, body, headers)
 func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -380,7 +339,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 
 	urlStr := call.Arguments[0].String()
 
-	// Validate domain
 	if err := r.validateDomain(urlStr); err != nil {
 		GoLog("[Extension:%s] HTTP blocked: %v\n", r.extensionID, err)
 		return r.vm.ToValue(map[string]interface{}{
@@ -391,9 +349,7 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	var bodyStr string
 	headers := make(map[string]string)
 
-	// For DELETE, second arg is headers; for PUT/PATCH, second arg is body
 	if method == "DELETE" {
-		// http.delete(url, headers)
 		if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 			headersObj := call.Arguments[1].Export()
 			if h, ok := headersObj.(map[string]interface{}); ok {
@@ -403,7 +359,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 			}
 		}
 	} else {
-		// http.put(url, body, headers) / http.patch(url, body, headers)
 		if len(call.Arguments) > 1 && !goja.IsUndefined(call.Arguments[1]) && !goja.IsNull(call.Arguments[1]) {
 			bodyArg := call.Arguments[1].Export()
 			switch v := bodyArg.(type) {
@@ -432,7 +387,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		}
 	}
 
-	// Create request
 	var reqBody io.Reader
 	if bodyStr != "" {
 		reqBody = strings.NewReader(bodyStr)
@@ -445,7 +399,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		})
 	}
 
-	// Set headers - user headers first
 	for k, v := range headers {
 		req.Header.Set(k, v)
 	}
@@ -456,7 +409,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		req.Header.Set("Content-Type", "application/json")
 	}
 
-	// Execute request
 	resp, err := r.httpClient.Do(req)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -465,7 +417,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	}
 	defer resp.Body.Close()
 
-	// Read body
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
@@ -473,7 +424,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 		})
 	}
 
-	// Extract response headers
 	respHeaders := make(map[string]interface{})
 	for k, v := range resp.Header {
 		if len(v) == 1 {
@@ -492,7 +442,6 @@ func (r *ExtensionRuntime) httpMethodShortcut(method string, call goja.FunctionC
 	})
 }
 
-// httpClearCookies clears all cookies for this extension
 func (r *ExtensionRuntime) httpClearCookies(call goja.FunctionCall) goja.Value {
 	if jar, ok := r.cookieJar.(*simpleCookieJar); ok {
 		jar.mu.Lock()

go_backend/extension_runtime_storage.go

@@ -17,12 +17,10 @@ import (
 
 // ==================== Storage API ====================
 
-// getStoragePath returns the path to the extension's storage file
 func (r *ExtensionRuntime) getStoragePath() string {
 	return filepath.Join(r.dataDir, "storage.json")
 }
 
-// loadStorage loads the storage data from disk
 func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	storagePath := r.getStoragePath()
 	data, err := os.ReadFile(storagePath)
@@ -41,7 +39,6 @@ func (r *ExtensionRuntime) loadStorage() (map[string]interface{}, error) {
 	return storage, nil
 }
 
-// saveStorage saves the storage data to disk
 func (r *ExtensionRuntime) saveStorage(storage map[string]interface{}) error {
 	storagePath := r.getStoragePath()
 	data, err := json.MarshalIndent(storage, "", "  ")
@@ -52,7 +49,6 @@ func (r *ExtensionRuntime) saveStorage(storage map[string]interface{}) error {
 	return os.WriteFile(storagePath, data, 0644)
 }
 
-// storageGet retrieves a value from storage
 func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -68,7 +64,6 @@ func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 
 	value, exists := storage[key]
 	if !exists {
-		// Return default value if provided
 		if len(call.Arguments) > 1 {
 			return call.Arguments[1]
 		}
@@ -78,7 +73,6 @@ func (r *ExtensionRuntime) storageGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-// storageSet stores a value in storage
 func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(false)
@@ -103,7 +97,6 @@ func (r *ExtensionRuntime) storageSet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-// storageRemove removes a value from storage
 func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -127,35 +120,27 @@ func (r *ExtensionRuntime) storageRemove(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(true)
 }
 
-// ==================== Credentials API (Encrypted Storage) ====================
-
-// getCredentialsPath returns the path to the extension's encrypted credentials file
 func (r *ExtensionRuntime) getCredentialsPath() string {
 	return filepath.Join(r.dataDir, ".credentials.enc")
 }
 
-// getSaltPath returns the path to the extension's encryption salt file
 func (r *ExtensionRuntime) getSaltPath() string {
 	return filepath.Join(r.dataDir, ".cred_salt")
 }
 
-// getOrCreateSalt gets existing salt or creates a new random one
 func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	saltPath := r.getSaltPath()
 
-	// Try to read existing salt
 	salt, err := os.ReadFile(saltPath)
 	if err == nil && len(salt) == 32 {
 		return salt, nil
 	}
 
-	// Generate new random salt (32 bytes)
 	salt = make([]byte, 32)
 	if _, err := io.ReadFull(rand.Reader, salt); err != nil {
 		return nil, fmt.Errorf("failed to generate salt: %w", err)
 	}
 
-	// Save salt to file
 	if err := os.WriteFile(saltPath, salt, 0600); err != nil {
 		return nil, fmt.Errorf("failed to save salt: %w", err)
 	}
@@ -163,22 +148,17 @@ func (r *ExtensionRuntime) getOrCreateSalt() ([]byte, error) {
 	return salt, nil
 }
 
-// getEncryptionKey derives an encryption key from extension ID + random salt
 func (r *ExtensionRuntime) getEncryptionKey() ([]byte, error) {
-	// Get or create per-installation random salt
 	salt, err := r.getOrCreateSalt()
 	if err != nil {
 		return nil, err
 	}
 
-	// Combine extension ID + random salt for key derivation
-	// This makes each installation unique, preventing mass decryption attacks
 	combined := append([]byte(r.extensionID), salt...)
 	hash := sha256.Sum256(combined)
 	return hash[:], nil
 }
 
-// loadCredentials loads and decrypts credentials from disk
 func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	credPath := r.getCredentialsPath()
 	data, err := os.ReadFile(credPath)
@@ -189,7 +169,6 @@ func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 		return nil, err
 	}
 
-	// Decrypt the data
 	key, err := r.getEncryptionKey()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get encryption key: %w", err)
@@ -207,14 +186,12 @@ func (r *ExtensionRuntime) loadCredentials() (map[string]interface{}, error) {
 	return creds, nil
 }
 
-// saveCredentials encrypts and saves credentials to disk
 func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	data, err := json.Marshal(creds)
 	if err != nil {
 		return err
 	}
 
-	// Encrypt the data
 	key, err := r.getEncryptionKey()
 	if err != nil {
 		return fmt.Errorf("failed to get encryption key: %w", err)
@@ -225,10 +202,9 @@ func (r *ExtensionRuntime) saveCredentials(creds map[string]interface{}) error {
 	}
 
 	credPath := r.getCredentialsPath()
-	return os.WriteFile(credPath, encrypted, 0600) // Restrictive permissions
+	return os.WriteFile(credPath, encrypted, 0600)
 }
 
-// credentialsStore stores an encrypted credential
 func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -264,7 +240,6 @@ func (r *ExtensionRuntime) credentialsStore(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// credentialsGet retrieves a decrypted credential
 func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -280,7 +255,6 @@ func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 
 	value, exists := creds[key]
 	if !exists {
-		// Return default value if provided
 		if len(call.Arguments) > 1 {
 			return call.Arguments[1]
 		}
@@ -290,7 +264,6 @@ func (r *ExtensionRuntime) credentialsGet(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(value)
 }
 
-// credentialsRemove removes a credential
 func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -314,7 +287,6 @@ func (r *ExtensionRuntime) credentialsRemove(call goja.FunctionCall) goja.Value
 	return r.vm.ToValue(true)
 }
 
-// credentialsHas checks if a credential exists
 func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue(false)
@@ -331,9 +303,6 @@ func (r *ExtensionRuntime) credentialsHas(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(exists)
 }
 
-// ==================== Crypto Utilities ====================
-
-// encryptAES encrypts data using AES-GCM
 func encryptAES(plaintext []byte, key []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {
@@ -354,7 +323,6 @@ func encryptAES(plaintext []byte, key []byte) ([]byte, error) {
 	return ciphertext, nil
 }
 
-// decryptAES decrypts data using AES-GCM
 func decryptAES(ciphertext []byte, key []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {

go_backend/extension_runtime_utils.go

@@ -12,13 +12,13 @@ import (
 	"encoding/json"
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/dop251/goja"
 )
 
 // ==================== Utility Functions ====================
 
-// base64Encode encodes a string to base64
 func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -27,7 +27,6 @@ func (r *ExtensionRuntime) base64Encode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString([]byte(input)))
 }
 
-// base64Decode decodes a base64 string
 func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -40,7 +39,6 @@ func (r *ExtensionRuntime) base64Decode(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(decoded))
 }
 
-// md5Hash computes MD5 hash of a string
 func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -50,7 +48,6 @@ func (r *ExtensionRuntime) md5Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-// sha256Hash computes SHA256 hash of a string
 func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -60,7 +57,6 @@ func (r *ExtensionRuntime) sha256Hash(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(hash[:]))
 }
 
-// hmacSHA256 computes HMAC-SHA256 of a message with a key
 func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
@@ -73,7 +69,6 @@ func (r *ExtensionRuntime) hmacSHA256(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(hex.EncodeToString(mac.Sum(nil)))
 }
 
-// hmacSHA256Base64 computes HMAC-SHA256 and returns base64 encoded result
 func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue("")
@@ -86,15 +81,11 @@ func (r *ExtensionRuntime) hmacSHA256Base64(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(base64.StdEncoding.EncodeToString(mac.Sum(nil)))
 }
 
-// hmacSHA1 computes HMAC-SHA1 of a message with a key (for TOTP)
-// Arguments: message (string or array of bytes), key (string or array of bytes)
-// Returns: array of bytes (for TOTP dynamic truncation)
 func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue([]byte{})
 	}
 
-	// Get key - can be string or array of bytes
 	var keyBytes []byte
 	keyArg := call.Arguments[0].Export()
 	switch k := keyArg.(type) {
@@ -113,7 +104,6 @@ func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 		return r.vm.ToValue([]byte{})
 	}
 
-	// Get message - can be string or array of bytes
 	var msgBytes []byte
 	msgArg := call.Arguments[1].Export()
 	switch m := msgArg.(type) {
@@ -136,7 +126,6 @@ func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	mac.Write(msgBytes)
 	result := mac.Sum(nil)
 
-	// Convert to array of numbers for JavaScript
 	jsArray := make([]interface{}, len(result))
 	for i, b := range result {
 		jsArray[i] = int(b)
@@ -144,7 +133,6 @@ func (r *ExtensionRuntime) hmacSHA1(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(jsArray)
 }
 
-// parseJSON parses a JSON string
 func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return goja.Undefined()
@@ -160,7 +148,6 @@ func (r *ExtensionRuntime) parseJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(result)
 }
 
-// stringifyJSON converts a value to JSON string
 func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -176,9 +163,6 @@ func (r *ExtensionRuntime) stringifyJSON(call goja.FunctionCall) goja.Value {
 	return r.vm.ToValue(string(data))
 }
 
-// ==================== Crypto Utilities for Extensions ====================
-
-// cryptoEncrypt encrypts a string using AES-GCM (for extension use)
 func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -190,7 +174,6 @@ func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	plaintext := call.Arguments[0].String()
 	keyStr := call.Arguments[1].String()
 
-	// Derive 32-byte key from provided key string
 	keyHash := sha256.Sum256([]byte(keyStr))
 
 	encrypted, err := encryptAES([]byte(plaintext), keyHash[:])
@@ -207,7 +190,6 @@ func (r *ExtensionRuntime) cryptoEncrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// cryptoDecrypt decrypts a string using AES-GCM (for extension use)
 func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 2 {
 		return r.vm.ToValue(map[string]interface{}{
@@ -227,14 +209,13 @@ func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 		})
 	}
 
-	// Derive 32-byte key from provided key string
 	keyHash := sha256.Sum256([]byte(keyStr))
 
 	decrypted, err := decryptAES(ciphertext, keyHash[:])
 	if err != nil {
 		return r.vm.ToValue(map[string]interface{}{
 			"success": false,
-			"error":   err.Error(),
+			"error":   "invalid base64 ciphertext",
 		})
 	}
 
@@ -244,9 +225,8 @@ func (r *ExtensionRuntime) cryptoDecrypt(call goja.FunctionCall) goja.Value {
 	})
 }
 
-// cryptoGenerateKey generates a random encryption key
 func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value {
-	length := 32 // Default 256-bit key
+	length := 32
 	if len(call.Arguments) > 0 && !goja.IsUndefined(call.Arguments[0]) {
 		if l, ok := call.Arguments[0].Export().(float64); ok {
 			length = int(l)
@@ -268,7 +248,9 @@ func (r *ExtensionRuntime) cryptoGenerateKey(call goja.FunctionCall) goja.Value
 	})
 }
 
-// ==================== Logging Functions ====================
+func (r *ExtensionRuntime) randomUserAgent(call goja.FunctionCall) goja.Value {
+	return r.vm.ToValue(getRandomUserAgent())
+}
 
 func (r *ExtensionRuntime) logDebug(call goja.FunctionCall) goja.Value {
 	msg := r.formatLogArgs(call.Arguments)
@@ -302,8 +284,6 @@ func (r *ExtensionRuntime) formatLogArgs(args []goja.Value) string {
 	return strings.Join(parts, " ")
 }
 
-// ==================== Go Backend Wrappers ====================
-
 func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.Value {
 	if len(call.Arguments) < 1 {
 		return r.vm.ToValue("")
@@ -312,7 +292,6 @@ func (r *ExtensionRuntime) sanitizeFilenameWrapper(call goja.FunctionCall) goja.
 	return r.vm.ToValue(sanitizeFilename(input))
 }
 
-// RegisterGoBackendAPIs adds more Go backend functions to the VM
 func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 	gobackendObj := vm.Get("gobackend")
 	if gobackendObj == nil || goja.IsUndefined(gobackendObj) {
@@ -322,7 +301,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 
 	obj := gobackendObj.(*goja.Object)
 
-	// Expose sanitizeFilename
 	obj.Set("sanitizeFilename", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 1 {
 			return vm.ToValue("")
@@ -330,7 +308,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 		return vm.ToValue(sanitizeFilename(call.Arguments[0].String()))
 	})
 
-	// Expose getAudioQuality
 	obj.Set("getAudioQuality", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 1 {
 			return vm.ToValue(map[string]interface{}{
@@ -353,7 +330,6 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 		})
 	})
 
-	// Expose buildFilename
 	obj.Set("buildFilename", func(call goja.FunctionCall) goja.Value {
 		if len(call.Arguments) < 2 {
 			return vm.ToValue("")
@@ -369,4 +345,23 @@ func (r *ExtensionRuntime) RegisterGoBackendAPIs(vm *goja.Runtime) {
 
 		return vm.ToValue(buildFilenameFromTemplate(template, metadata))
 	})
+
+	obj.Set("getLocalTime", func(call goja.FunctionCall) goja.Value {
+		now := time.Now()
+		_, offsetSeconds := now.Zone()
+		offsetMinutes := offsetSeconds / 60
+
+		return vm.ToValue(map[string]interface{}{
+			"year":          now.Year(),
+			"month":         int(now.Month()),
+			"day":           now.Day(),
+			"hour":          now.Hour(),
+			"minute":        now.Minute(),
+			"second":        now.Second(),
+			"weekday":       int(now.Weekday()),
+			"offsetMinutes": -offsetMinutes, // JS convention: negative for east of UTC
+			"timezone":      now.Location().String(),
+			"timestamp":     now.Unix(),
+		})
+	})
 }

go_backend/extension_settings.go

@@ -9,7 +9,6 @@ import (
 	"sync"
 )
 
-// ExtensionSettingsStore manages settings for all extensions
 type ExtensionSettingsStore struct {
 	mu       sync.RWMutex
 	dataDir  string
@@ -22,7 +21,6 @@ var (
 	globalSettingsStoreOnce sync.Once
 )
 
-// GetExtensionSettingsStore returns the global settings store
 func GetExtensionSettingsStore() *ExtensionSettingsStore {
 	globalSettingsStoreOnce.Do(func() {
 		globalSettingsStore = &ExtensionSettingsStore{
@@ -32,7 +30,6 @@ func GetExtensionSettingsStore() *ExtensionSettingsStore {
 	return globalSettingsStore
 }
 
-// SetDataDir sets the data directory for settings storage
 func (s *ExtensionSettingsStore) SetDataDir(dataDir string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -42,16 +39,13 @@ func (s *ExtensionSettingsStore) SetDataDir(dataDir string) error {
 		return fmt.Errorf("failed to create settings directory: %w", err)
 	}
 
-	// Load all existing settings
 	return s.loadAllSettings()
 }
 
-// getSettingsPath returns the path to an extension's settings file
 func (s *ExtensionSettingsStore) getSettingsPath(extensionID string) string {
 	return filepath.Join(s.dataDir, extensionID, "settings.json")
 }
 
-// loadAllSettings loads settings for all extensions from disk
 func (s *ExtensionSettingsStore) loadAllSettings() error {
 	entries, err := os.ReadDir(s.dataDir)
 	if err != nil {
@@ -76,7 +70,6 @@ func (s *ExtensionSettingsStore) loadAllSettings() error {
 	return nil
 }
 
-// loadSettings loads settings for a specific extension
 func (s *ExtensionSettingsStore) loadSettings(extensionID string) (map[string]interface{}, error) {
 	settingsPath := s.getSettingsPath(extensionID)
 	data, err := os.ReadFile(settingsPath)
@@ -95,11 +88,9 @@ func (s *ExtensionSettingsStore) loadSettings(extensionID string) (map[string]in
 	return settings, nil
 }
 
-// saveSettings saves settings for a specific extension
 func (s *ExtensionSettingsStore) saveSettings(extensionID string, settings map[string]interface{}) error {
 	settingsPath := s.getSettingsPath(extensionID)
 
-	// Create directory if needed
 	dir := filepath.Dir(settingsPath)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return err
@@ -113,8 +104,6 @@ func (s *ExtensionSettingsStore) saveSettings(extensionID string, settings map[s
 	return os.WriteFile(settingsPath, data, 0644)
 }
 
-// Get retrieves a setting value for an extension
-// Returns error if extension or key not found (gomobile compatible)
 func (s *ExtensionSettingsStore) Get(extensionID, key string) (interface{}, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -131,7 +120,6 @@ func (s *ExtensionSettingsStore) Get(extensionID, key string) (interface{}, erro
 	return value, nil
 }
 
-// GetAll retrieves all settings for an extension
 func (s *ExtensionSettingsStore) GetAll(extensionID string) map[string]interface{} {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
@@ -149,7 +137,6 @@ func (s *ExtensionSettingsStore) GetAll(extensionID string) map[string]interface
 	return result
 }
 
-// Set stores a setting value for an extension
 func (s *ExtensionSettingsStore) Set(extensionID, key string, value interface{}) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -160,11 +147,9 @@ func (s *ExtensionSettingsStore) Set(extensionID, key string, value interface{})
 
 	s.settings[extensionID][key] = value
 
-	// Persist to disk
 	return s.saveSettings(extensionID, s.settings[extensionID])
 }
 
-// SetAll stores all settings for an extension
 func (s *ExtensionSettingsStore) SetAll(extensionID string, settings map[string]interface{}) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -175,7 +160,6 @@ func (s *ExtensionSettingsStore) SetAll(extensionID string, settings map[string]
 	return s.saveSettings(extensionID, settings)
 }
 
-// Remove removes a setting for an extension
 func (s *ExtensionSettingsStore) Remove(extensionID, key string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -191,14 +175,12 @@ func (s *ExtensionSettingsStore) Remove(extensionID, key string) error {
 	return s.saveSettings(extensionID, extSettings)
 }
 
-// RemoveAll removes all settings for an extension
 func (s *ExtensionSettingsStore) RemoveAll(extensionID string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
 	delete(s.settings, extensionID)
 
-	// Remove settings file
 	settingsPath := s.getSettingsPath(extensionID)
 	if err := os.Remove(settingsPath); err != nil && !os.IsNotExist(err) {
 		return err
@@ -207,7 +189,6 @@ func (s *ExtensionSettingsStore) RemoveAll(extensionID string) error {
 	return nil
 }
 
-// GetAllExtensionSettings returns settings for all extensions as JSON
 func (s *ExtensionSettingsStore) GetAllExtensionSettingsJSON() (string, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()

go_backend/extension_store.go

@@ -20,29 +20,26 @@ const (
 	CategoryIntegration = "integration"
 )
 
-// StoreExtension represents an extension in the store
 type StoreExtension struct {
-	ID            string   `json:"id"`
+	ID               string   `json:"id"`
-	Name          string   `json:"name"`
+	Name             string   `json:"name"`
-	DisplayName   string   `json:"display_name,omitempty"`
+	DisplayName      string   `json:"display_name,omitempty"`
-	Version       string   `json:"version"`
+	Version          string   `json:"version"`
-	Author        string   `json:"author"`
+	Author           string   `json:"author"`
-	Description   string   `json:"description"`
+	Description      string   `json:"description"`
-	DownloadURL   string   `json:"download_url,omitempty"`
+	DownloadURL      string   `json:"download_url,omitempty"`
-	IconURL       string   `json:"icon_url,omitempty"`
+	IconURL          string   `json:"icon_url,omitempty"`
-	Category      string   `json:"category"`
+	Category         string   `json:"category"`
-	Tags          []string `json:"tags,omitempty"`
+	Tags             []string `json:"tags,omitempty"`
-	Downloads     int      `json:"downloads"`
+	Downloads        int      `json:"downloads"`
-	UpdatedAt     string   `json:"updated_at"`
+	UpdatedAt        string   `json:"updated_at"`
-	MinAppVersion string   `json:"min_app_version,omitempty"`
+	MinAppVersion    string   `json:"min_app_version,omitempty"`
-	// Alternative camelCase fields (for flexibility)
+	DisplayNameAlt   string   `json:"displayName,omitempty"`
-	DisplayNameAlt   string `json:"displayName,omitempty"`
+	DownloadURLAlt   string   `json:"downloadUrl,omitempty"`
-	DownloadURLAlt   string `json:"downloadUrl,omitempty"`
+	IconURLAlt       string   `json:"iconUrl,omitempty"`
-	IconURLAlt       string `json:"iconUrl,omitempty"`
+	MinAppVersionAlt string   `json:"minAppVersion,omitempty"`
-	MinAppVersionAlt string `json:"minAppVersion,omitempty"`
 }
 
-// getDisplayName returns display name, falling back to name (private to avoid gomobile conflict)
 func (e *StoreExtension) getDisplayName() string {
 	if e.DisplayName != "" {
 		return e.DisplayName
@@ -53,7 +50,6 @@ func (e *StoreExtension) getDisplayName() string {
 	return e.Name
 }
 
-// getDownloadURL returns download URL from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getDownloadURL() string {
 	if e.DownloadURL != "" {
 		return e.DownloadURL
@@ -61,7 +57,6 @@ func (e *StoreExtension) getDownloadURL() string {
 	return e.DownloadURLAlt
 }
 
-// getIconURL returns icon URL from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getIconURL() string {
 	if e.IconURL != "" {
 		return e.IconURL
@@ -69,7 +64,6 @@ func (e *StoreExtension) getIconURL() string {
 	return e.IconURLAlt
 }
 
-// getMinAppVersion returns min app version from either field (private to avoid gomobile conflict)
 func (e *StoreExtension) getMinAppVersion() string {
 	if e.MinAppVersion != "" {
 		return e.MinAppVersion
@@ -77,7 +71,6 @@ func (e *StoreExtension) getMinAppVersion() string {
 	return e.MinAppVersionAlt
 }
 
-// StoreRegistry represents the extension registry
 type StoreRegistry struct {
 	Version    int              `json:"version"`
 	UpdatedAt  string           `json:"updated_at"`
@@ -104,7 +97,6 @@ type StoreExtensionResponse struct {
 	HasUpdate        bool     `json:"has_update"`
 }
 
-// ToResponse converts StoreExtension to normalized response
 func (e *StoreExtension) ToResponse() StoreExtensionResponse {
 	return StoreExtensionResponse{
 		ID:            e.ID,
@@ -123,7 +115,6 @@ func (e *StoreExtension) ToResponse() StoreExtensionResponse {
 	}
 }
 
-// ExtensionStore manages the extension store
 type ExtensionStore struct {
 	registryURL string
 	cacheDir    string
@@ -144,7 +135,6 @@ const (
 	cacheFileName      = "store_cache.json"
 )
 
-// InitExtensionStore initializes the extension store
 func InitExtensionStore(cacheDir string) *ExtensionStore {
 	extensionStoreMu.Lock()
 	defer extensionStoreMu.Unlock()
@@ -161,14 +151,12 @@ func InitExtensionStore(cacheDir string) *ExtensionStore {
 	return extensionStore
 }
 
-// GetExtensionStore returns the singleton store instance
 func GetExtensionStore() *ExtensionStore {
 	extensionStoreMu.Lock()
 	defer extensionStoreMu.Unlock()
 	return extensionStore
 }
 
-// loadDiskCache loads cached registry from disk
 func (s *ExtensionStore) loadDiskCache() {
 	if s.cacheDir == "" {
 		return
@@ -194,7 +182,6 @@ func (s *ExtensionStore) loadDiskCache() {
 	LogDebug("ExtensionStore", "Loaded %d extensions from disk cache", len(s.cache.Extensions))
 }
 
-// saveDiskCache saves registry to disk cache
 func (s *ExtensionStore) saveDiskCache() {
 	if s.cacheDir == "" || s.cache == nil {
 		return
@@ -217,7 +204,6 @@ func (s *ExtensionStore) saveDiskCache() {
 	os.WriteFile(cachePath, data, 0644)
 }
 
-// FetchRegistry fetches the extension registry from GitHub
 func (s *ExtensionStore) FetchRegistry(forceRefresh bool) (*StoreRegistry, error) {
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()
@@ -268,7 +254,6 @@ func (s *ExtensionStore) FetchRegistry(forceRefresh bool) (*StoreRegistry, error
 	return &registry, nil
 }
 
-// GetExtensionsWithStatus returns extensions with installation status
 func (s *ExtensionStore) GetExtensionsWithStatus() ([]StoreExtensionResponse, error) {
 	registry, err := s.FetchRegistry(false)
 	if err != nil {
@@ -300,7 +285,6 @@ func (s *ExtensionStore) GetExtensionsWithStatus() ([]StoreExtensionResponse, er
 	return result, nil
 }
 
-// DownloadExtension downloads an extension package to the specified path
 func (s *ExtensionStore) DownloadExtension(extensionID string, destPath string) error {
 	registry, err := s.FetchRegistry(false)
 	if err != nil {
@@ -332,7 +316,6 @@ func (s *ExtensionStore) DownloadExtension(extensionID string, destPath string)
 		return fmt.Errorf("download returned HTTP %d", resp.StatusCode)
 	}
 
-	// Create destination file
 	out, err := os.Create(destPath)
 	if err != nil {
 		return fmt.Errorf("failed to create file: %w", err)
@@ -349,7 +332,6 @@ func (s *ExtensionStore) DownloadExtension(extensionID string, destPath string)
 	return nil
 }
 
-// GetCategories returns all available categories
 func (s *ExtensionStore) GetCategories() []string {
 	return []string{
 		CategoryMetadata,
@@ -360,7 +342,6 @@ func (s *ExtensionStore) GetCategories() []string {
 	}
 }
 
-// SearchExtensions searches extensions by query
 func (s *ExtensionStore) SearchExtensions(query string, category string) ([]StoreExtensionResponse, error) {
 	extensions, err := s.GetExtensionsWithStatus()
 	if err != nil {
@@ -406,7 +387,6 @@ func (s *ExtensionStore) SearchExtensions(query string, category string) ([]Stor
 	return result, nil
 }
 
-// ClearCache clears the in-memory and disk cache
 func (s *ExtensionStore) ClearCache() {
 	s.cacheMu.Lock()
 	defer s.cacheMu.Unlock()

go_backend/filename.go

@@ -6,28 +6,21 @@ import (
 	"strings"
 )
 
-// Invalid filename characters for Android/Windows/Linux
 var invalidChars = regexp.MustCompile(`[<>:"/\\|?*\x00-\x1f]`)
 
-// sanitizeFilename removes invalid characters from filename
 func sanitizeFilename(filename string) string {
-	// Replace invalid characters with underscore
 	sanitized := invalidChars.ReplaceAllString(filename, "_")
 	
-	// Remove leading/trailing spaces and dots
 	sanitized = strings.TrimSpace(sanitized)
 	sanitized = strings.Trim(sanitized, ".")
 	
-	// Collapse multiple underscores
 	multiUnderscore := regexp.MustCompile(`_+`)
 	sanitized = multiUnderscore.ReplaceAllString(sanitized, "_")
 	
-	// Limit length (Android has 255 byte limit for filenames)
 	if len(sanitized) > 200 {
 		sanitized = sanitized[:200]
 	}
 	
-	// Ensure not empty
 	if sanitized == "" {
 		sanitized = "untitled"
 	}
@@ -35,7 +28,6 @@ func sanitizeFilename(filename string) string {
 	return sanitized
 }
 
-// buildFilenameFromTemplate builds a filename from template and metadata
 func buildFilenameFromTemplate(template string, metadata map[string]interface{}) string {
 	if template == "" {
 		template = "{artist} - {title}"
@@ -43,7 +35,6 @@ func buildFilenameFromTemplate(template string, metadata map[string]interface{})
 	
 	result := template
 	
-	// Replace placeholders
 	placeholders := map[string]string{
 		"{title}":  getString(metadata, "title"),
 		"{artist}": getString(metadata, "artist"),
@@ -63,7 +54,6 @@ func buildFilenameFromTemplate(template string, metadata map[string]interface{})
 func getString(m map[string]interface{}, key string) string {
 	if v, ok := m[key]; ok {
 		if s, ok := v.(string); ok {
-			// Trim leading/trailing whitespace to prevent filename issues
 			return strings.TrimSpace(s)
 		}
 	}
@@ -98,7 +88,6 @@ func formatDiscNumber(n int) string {
 	return fmt.Sprintf("%d", n)
 }
 
-// extractYear extracts year from date string (YYYY-MM-DD or YYYY)
 func extractYear(date string) string {
 	if len(date) >= 4 {
 		return date[:4]

go_backend/go.mod

@@ -1,23 +1,29 @@
 module github.com/zarz/spotiflac_android/go_backend
 
-go 1.24.0
+go 1.25.0
 
-toolchain go1.24.5
+toolchain go1.25.6
 
 require (
 	github.com/dop251/goja v0.0.0-20260106131823-651366fbe6e3
 	github.com/go-flac/flacpicture v0.3.0
 	github.com/go-flac/flacvorbis v0.2.0
 	github.com/go-flac/go-flac v1.0.0
+	github.com/refraction-networking/utls v1.8.2
+	golang.org/x/mobile v0.0.0-20260120165949-40bd9ace6ce4
+	golang.org/x/net v0.49.0
 )
 
 require (
+	github.com/andybalholm/brotli v1.0.6 // indirect
 	github.com/dlclark/regexp2 v1.11.4 // indirect
 	github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect
 	github.com/google/pprof v0.0.0-20230207041349-798e818bf904 // indirect
-	golang.org/x/mobile v0.0.0-20251209145715-2553ed8ce294 // indirect
+	github.com/klauspost/compress v1.17.4 // indirect
-	golang.org/x/mod v0.31.0 // indirect
+	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/mod v0.32.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
-	golang.org/x/text v0.3.8 // indirect
+	golang.org/x/sys v0.40.0 // indirect
-	golang.org/x/tools v0.40.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
+	golang.org/x/tools v0.41.0 // indirect
 )

go_backend/go.sum

@@ -1,5 +1,7 @@
 github.com/Masterminds/semver/v3 v3.2.1 h1:RN9w6+7QoMeJVGyfmbcgs28Br8cvmnucEXnY0rYXWg0=
 github.com/Masterminds/semver/v3 v3.2.1/go.mod h1:qvl/7zhW3nngYb5+80sSMF+FG2BjYrf8m9wsX0PNOMQ=
+github.com/andybalholm/brotli v1.0.6 h1:Yf9fFpf49Zrxb9NlQaluyE92/+X7UVHlhMNJN2sxfOI=
+github.com/andybalholm/brotli v1.0.6/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
 github.com/dlclark/regexp2 v1.11.4 h1:rPYF9/LECdNymJufQKmri9gV604RvvABwgOA8un7yAo=
 github.com/dlclark/regexp2 v1.11.4/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
 github.com/dop251/goja v0.0.0-20260106131823-651366fbe6e3 h1:bVp3yUzvSAJzu9GqID+Z96P+eu5TKnIMJSV4QaZMauM=
@@ -12,17 +14,29 @@ github.com/go-flac/go-flac v1.0.0 h1:6qI9XOVLcO50xpzm3nXvO31BgDgHhnr/p/rER/K/doY
 github.com/go-flac/go-flac v1.0.0/go.mod h1:WnZhcpmq4u1UdZMNn9LYSoASpWOCMOoxXxcWEHSzkW8=
 github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyLFfuisuzeidWPMPWmECqU=
 github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/pprof v0.0.0-20230207041349-798e818bf904 h1:4/hN5RUoecvl+RmJRE2YxKWtnnQls6rQjjW5oV7qg2U=
 github.com/google/pprof v0.0.0-20230207041349-798e818bf904/go.mod h1:uglQLonpP8qtYCYyzA+8c/9qtqgA3qsXGYqCPKARAFg=
-golang.org/x/mobile v0.0.0-20251209145715-2553ed8ce294 h1:Cr6kbEvA6nqvdHynE4CtVKlqpZB9dS1Jva/6IsHA19g=
+github.com/klauspost/compress v1.17.4 h1:Ej5ixsIri7BrIjBkRZLTo6ghwrEtHFk7ijlczPW4fZ4=
-golang.org/x/mobile v0.0.0-20251209145715-2553ed8ce294/go.mod h1:RdZ+3sb4CVgpCFnzv+I4haEpwqFfsfzlLHs3L7ok+e0=
+github.com/klauspost/compress v1.17.4/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
-golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
+github.com/refraction-networking/utls v1.8.2 h1:j4Q1gJj0xngdeH+Ox/qND11aEfhpgoEvV+S9iJ2IdQo=
-golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+github.com/refraction-networking/utls v1.8.2/go.mod h1:jkSOEkLqn+S/jtpEHPOsVv/4V4EVnelwbMQl4vCWXAM=
+golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
+golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
+golang.org/x/mobile v0.0.0-20260120165949-40bd9ace6ce4 h1:C3JuLOLhdaE75vk5m7u18NvZciRk+lnO34xcXl3NPTU=
+golang.org/x/mobile v0.0.0-20260120165949-40bd9ace6ce4/go.mod h1:yHJY0EGzMJ0i5ONrrhdpDSSnoyres5LO7D2hSIbJJ5I=
+golang.org/x/mod v0.32.0 h1:9F4d3PHLljb6x//jOyokMv3eX+YDeepZSEo3mFJy93c=
+golang.org/x/mod v0.32.0/go.mod h1:SgipZ/3h2Ci89DlEtEXWUk/HteuRin+HHhN+WbNhguU=
+golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
+golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
 golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
-golang.org/x/text v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
+golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
-golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
+golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
+golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
-golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
+golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
+golang.org/x/tools v0.41.0 h1:a9b8iMweWG+S0OBnlU36rzLp20z1Rp10w+IY2czHTQc=
+golang.org/x/tools v0.41.0/go.mod h1:XSY6eDqxVNiYgezAVqqCeihT4j1U2CCsqvH3WhQpnlg=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

go_backend/httputil.go

@@ -15,76 +15,29 @@ import (
 	"time"
 )
 
-// HTTP utility functions for consistent request handling across all downloaders
-
-// 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
+	// Chrome version 120-145 (modern range)
-	// Some APIs may block mobile User-Agents, so we use desktop format
+	chromeVersion := rand.Intn(26) + 120
-	winMajor := rand.Intn(2) + 10 // Windows 10 or 11
+	chromeBuild := rand.Intn(1500) + 6000
-
+	chromePatch := rand.Intn(200) + 100
-	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",
+		"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%d.0.%d.%d Safari/537.36",
-		winMajor,
 		chromeVersion,
 		chromeBuild,
 		chromePatch,
 	)
 }
 
-// getRandomMacUserAgent generates a random Mac Chrome User-Agent string
-// Alternative format matching referensi/backend/spotify_metadata.go exactly
-// Kept for potential future use
-// 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
-//
-// 	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,
-// 	)
-// }
-
-// getRandomDesktopUserAgent randomly picks between Windows and Mac User-Agent
-// Kept for potential future use
-// func getRandomDesktopUserAgent() string {
-// 	if rand.Intn(2) == 0 {
-// 		return getRandomUserAgent() // Windows
-// 	}
-// 	return getRandomMacUserAgent() // Mac
-// }
-
-// Default timeout values
 const (
-	DefaultTimeout    = 60 * time.Second  // Default HTTP timeout
+	DefaultTimeout    = 60 * time.Second
-	DownloadTimeout   = 120 * time.Second // Timeout for file downloads
+	DownloadTimeout   = 120 * time.Second
-	SongLinkTimeout   = 30 * time.Second  // Timeout for SongLink API
+	SongLinkTimeout   = 30 * time.Second
-	DefaultMaxRetries = 3                 // Default retry count
+	DefaultMaxRetries = 3
-	DefaultRetryDelay = 1 * time.Second   // Initial retry delay
+	DefaultRetryDelay = 1 * time.Second
+	Second            = time.Second
 )
 
-// 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,
@@ -96,27 +49,23 @@ var sharedTransport = &http.Transport{
 	IdleConnTimeout:       90 * time.Second,
 	TLSHandshakeTimeout:   10 * time.Second,
 	ExpectContinueTimeout: 1 * time.Second,
-	DisableKeepAlives:     false, // Enable keep-alives for connection reuse
+	DisableKeepAlives:     false,
 	ForceAttemptHTTP2:     true,
-	WriteBufferSize:       64 * 1024, // 64KB write buffer
+	WriteBufferSize:       64 * 1024,
-	ReadBufferSize:        64 * 1024, // 64KB read buffer
+	ReadBufferSize:        64 * 1024,
-	DisableCompression:    true,      // FLAC is already compressed
+	DisableCompression:    true,
 }
 
-// Shared HTTP client for general requests (reuses connections)
 var sharedClient = &http.Client{
 	Transport: sharedTransport,
 	Timeout:   DefaultTimeout,
 }
 
-// Shared HTTP client for downloads (longer timeout, reuses connections)
 var downloadClient = &http.Client{
 	Transport: sharedTransport,
 	Timeout:   DownloadTimeout,
 }
 
-// NewHTTPClientWithTimeout creates an HTTP client with specified timeout
-// Uses shared transport for connection reuse
 func NewHTTPClientWithTimeout(timeout time.Duration) *http.Client {
 	return &http.Client{
 		Transport: sharedTransport,
@@ -124,29 +73,23 @@ func NewHTTPClientWithTimeout(timeout time.Duration) *http.Client {
 	}
 }
 
-// GetSharedClient returns the shared HTTP client for general requests
 func GetSharedClient() *http.Client {
 	return sharedClient
 }
 
-// GetDownloadClient returns the shared HTTP client for downloads
 func GetDownloadClient() *http.Client {
 	return downloadClient
 }
 
-// CloseIdleConnections closes idle connections in the shared transport
-// Call this periodically during large batch downloads to prevent connection buildup
 func CloseIdleConnections() {
 	sharedTransport.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())
 	resp, err := client.Do(req)
 	if err != nil {
-		// Check for ISP blocking
 		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
 	}
 	return resp, err
@@ -160,7 +103,6 @@ type RetryConfig struct {
 	BackoffFactor float64
 }
 
-// DefaultRetryConfig returns default retry configuration
 func DefaultRetryConfig() RetryConfig {
 	return RetryConfig{
 		MaxRetries:    DefaultMaxRetries,
@@ -170,9 +112,6 @@ func DefaultRetryConfig() RetryConfig {
 	}
 }
 
-// DoRequestWithRetry executes an HTTP request with retry logic and exponential backoff
-// Handles 429 (Too Many Requests) responses with Retry-After header
-// Also detects and logs ISP blocking
 func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConfig) (*http.Response, error) {
 	var lastErr error
 	delay := config.InitialDelay
@@ -202,12 +141,10 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			continue
 		}
 
-		// Success
 		if resp.StatusCode >= 200 && resp.StatusCode < 300 {
 			return resp, nil
 		}
 
-		// Handle rate limiting (429)
 		if resp.StatusCode == 429 {
 			resp.Body.Close()
 			retryAfter := getRetryAfterDuration(resp)
@@ -247,7 +184,6 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			}
 		}
 
-		// Server errors (5xx) - retry
 		if resp.StatusCode >= 500 {
 			resp.Body.Close()
 			lastErr = fmt.Errorf("server error: HTTP %d", resp.StatusCode)
@@ -259,20 +195,17 @@ func DoRequestWithRetry(client *http.Client, req *http.Request, config RetryConf
 			continue
 		}
 
-		// Client errors (4xx except 429) - don't retry
 		return resp, nil
 	}
 
 	return nil, fmt.Errorf("request failed after %d retries: %w", config.MaxRetries+1, lastErr)
 }
 
-// calculateNextDelay calculates the next delay with exponential backoff
 func calculateNextDelay(currentDelay time.Duration, config RetryConfig) time.Duration {
 	nextDelay := time.Duration(float64(currentDelay) * config.BackoffFactor)
 	return min(nextDelay, config.MaxDelay)
 }
 
-// getRetryAfterDuration parses Retry-After header and returns duration
 // Returns 60 seconds as default if header is missing or invalid
 func getRetryAfterDuration(resp *http.Response) time.Duration {
 	retryAfter := resp.Header.Get("Retry-After")
@@ -280,12 +213,10 @@ func getRetryAfterDuration(resp *http.Response) time.Duration {
 		return 60 * time.Second // Default wait time
 	}
 
-	// Try parsing as seconds
 	if seconds, err := strconv.Atoi(retryAfter); err == nil {
 		return time.Duration(seconds) * time.Second
 	}
 
-	// Try parsing as HTTP date
 	if t, err := http.ParseTime(retryAfter); err == nil {
 		duration := time.Until(t)
 		if duration > 0 {
@@ -296,8 +227,6 @@ func getRetryAfterDuration(resp *http.Response) time.Duration {
 	return 60 * time.Second // Default
 }
 
-// ReadResponseBody reads and returns the response body
-// Returns error if body is empty
 func ReadResponseBody(resp *http.Response) ([]byte, error) {
 	if resp == nil {
 		return nil, fmt.Errorf("response is nil")
@@ -315,7 +244,6 @@ func ReadResponseBody(resp *http.Response) ([]byte, error) {
 	return body, nil
 }
 
-// ValidateResponse checks if response is valid (non-nil, status 2xx)
 func ValidateResponse(resp *http.Response) error {
 	if resp == nil {
 		return fmt.Errorf("response is nil")
@@ -328,14 +256,12 @@ func ValidateResponse(resp *http.Response) error {
 	return nil
 }
 
-// BuildErrorMessage creates a detailed error message for API failures
 func BuildErrorMessage(apiURL string, statusCode int, responsePreview string) string {
 	msg := fmt.Sprintf("API %s failed", apiURL)
 	if statusCode > 0 {
 		msg += fmt.Sprintf(" (HTTP %d)", statusCode)
 	}
 	if responsePreview != "" {
-		// Truncate preview if too long
 		if len(responsePreview) > 100 {
 			responsePreview = responsePreview[:100] + "..."
 		}
@@ -344,7 +270,6 @@ 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
@@ -355,18 +280,14 @@ func (e *ISPBlockingError) Error() string {
 	return fmt.Sprintf("ISP blocking detected for %s: %s", e.Domain, e.Reason)
 }
 
-// IsISPBlocking checks if an error is likely caused by ISP blocking
-// Returns the ISPBlockingError if detected, nil otherwise
 func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 	if err == nil {
 		return nil
 	}
 
-	// Extract domain from URL
 	domain := extractDomain(requestURL)
 	errStr := strings.ToLower(err.Error())
 
-	// Check for DNS resolution failure (common ISP blocking method)
 	var dnsErr *net.DNSError
 	if errors.As(err, &dnsErr) {
 		if dnsErr.IsNotFound || dnsErr.IsTemporary {
@@ -378,11 +299,9 @@ func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 		}
 	}
 
-	// Check for connection refused (ISP firewall blocking)
 	var opErr *net.OpError
 	if errors.As(err, &opErr) {
 		if opErr.Op == "dial" {
-			// Check for specific syscall errors
 			var syscallErr syscall.Errno
 			if errors.As(opErr.Err, &syscallErr) {
 				switch syscallErr {
@@ -421,7 +340,6 @@ func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 		}
 	}
 
-	// Check for TLS handshake failure (ISP MITM or blocking HTTPS)
 	var tlsErr *tls.RecordHeaderError
 	if errors.As(err, &tlsErr) {
 		return &ISPBlockingError{
@@ -460,7 +378,6 @@ func IsISPBlocking(err error, requestURL string) *ISPBlockingError {
 	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)
@@ -483,7 +400,6 @@ func extractDomain(rawURL string) string {
 
 	parsed, err := url.Parse(rawURL)
 	if err != nil {
-		// Try to extract domain manually
 		rawURL = strings.TrimPrefix(rawURL, "https://")
 		rawURL = strings.TrimPrefix(rawURL, "http://")
 		if idx := strings.Index(rawURL, "/"); idx > 0 {
@@ -498,7 +414,6 @@ func extractDomain(rawURL string) string {
 	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 {

go_backend/httputil_ios.go

@@ -0,0 +1,27 @@
+//go:build ios
+
+package gobackend
+
+import (
+	"net/http"
+)
+
+// iOS version: uTLS is not supported on iOS due to cgo DNS resolver issues
+// Fall back to standard HTTP client
+
+// GetCloudflareBypassClient returns the standard HTTP client on iOS
+// uTLS is not available on iOS due to cgo DNS resolver compatibility issues
+func GetCloudflareBypassClient() *http.Client {
+	return sharedClient
+}
+
+// DoRequestWithCloudflareBypass on iOS just uses the standard client
+// uTLS Chrome fingerprint bypass is not available on iOS
+func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
+	req.Header.Set("User-Agent", getRandomUserAgent())
+	resp, err := sharedClient.Do(req)
+	if err != nil {
+		CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
+	}
+	return resp, err
+}

go_backend/httputil_utls.go

@@ -0,0 +1,188 @@
+//go:build !ios
+
+package gobackend
+
+import (
+	"context"
+	"crypto/tls"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+
+	utls "github.com/refraction-networking/utls"
+	"golang.org/x/net/http2"
+)
+
+// uTLS transport that mimics Chrome's TLS fingerprint to bypass Cloudflare
+// Uses HTTP/2 for optimal performance as uTLS works best with HTTP/2
+type utlsTransport struct {
+	dialer       *net.Dialer
+	mu           sync.Mutex
+	h2Transports map[string]*http2.Transport
+}
+
+func newUTLSTransport() *utlsTransport {
+	return &utlsTransport{
+		dialer: &net.Dialer{
+			Timeout:   30 * Second,
+			KeepAlive: 30 * Second,
+		},
+		h2Transports: make(map[string]*http2.Transport),
+	}
+}
+
+func (t *utlsTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	// For non-HTTPS, use standard transport
+	if req.URL.Scheme != "https" {
+		return sharedTransport.RoundTrip(req)
+	}
+
+	host := req.URL.Hostname()
+	port := t.getPort(req.URL)
+	addr := net.JoinHostPort(host, port)
+
+	// Dial TCP connection
+	conn, err := t.dialer.DialContext(req.Context(), "tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create uTLS connection with Chrome fingerprint (supports HTTP/2 ALPN)
+	tlsConn := utls.UClient(conn, &utls.Config{
+		ServerName: host,
+		NextProtos: []string{"h2", "http/1.1"}, // Prefer HTTP/2
+	}, utls.HelloChrome_Auto)
+
+	// Perform TLS handshake
+	if err := tlsConn.Handshake(); err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	// Check if server supports HTTP/2
+	negotiatedProto := tlsConn.ConnectionState().NegotiatedProtocol
+
+	if negotiatedProto == "h2" {
+		// Use HTTP/2 transport
+		h2Transport := &http2.Transport{
+			DialTLSContext: func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
+				return tlsConn, nil
+			},
+			AllowHTTP:          false,
+			DisableCompression: false,
+		}
+		return h2Transport.RoundTrip(req)
+	}
+
+	// Fallback to HTTP/1.1
+	transport := &http.Transport{
+		DialTLSContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+			return tlsConn, nil
+		},
+		DisableKeepAlives: true,
+	}
+
+	return transport.RoundTrip(req)
+}
+
+func (t *utlsTransport) getPort(u *url.URL) string {
+	if u.Port() != "" {
+		return u.Port()
+	}
+	if u.Scheme == "https" {
+		return "443"
+	}
+	return "80"
+}
+
+// Cloudflare bypass client using uTLS Chrome fingerprint
+var cloudflareBypassTransport = newUTLSTransport()
+
+var cloudflareBypassClient = &http.Client{
+	Transport: cloudflareBypassTransport,
+	Timeout:   DefaultTimeout,
+}
+
+// GetCloudflareBypassClient returns an HTTP client that mimics Chrome's TLS fingerprint
+// Use this when requests are blocked by Cloudflare (common when using VPN)
+func GetCloudflareBypassClient() *http.Client {
+	return cloudflareBypassClient
+}
+
+// DoRequestWithCloudflareBypass attempts request with standard client first,
+// then retries with uTLS Chrome fingerprint if Cloudflare blocks it.
+// This is useful when using VPN as Cloudflare detects Go's default TLS fingerprint.
+func DoRequestWithCloudflareBypass(req *http.Request) (*http.Response, error) {
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	// Try with standard client first
+	resp, err := sharedClient.Do(req)
+	if err == nil {
+		// Check for Cloudflare challenge page (403 with specific markers)
+		if resp.StatusCode == 403 || resp.StatusCode == 503 {
+			body, readErr := io.ReadAll(resp.Body)
+			resp.Body.Close()
+
+			if readErr == nil {
+				bodyStr := strings.ToLower(string(body))
+				cloudflareMarkers := []string{
+					"cloudflare", "cf-ray", "checking your browser",
+					"please wait", "ddos protection", "ray id",
+					"enable javascript", "challenge-platform",
+				}
+
+				isCloudflare := false
+				for _, marker := range cloudflareMarkers {
+					if strings.Contains(bodyStr, marker) {
+						isCloudflare = true
+						break
+					}
+				}
+
+				if isCloudflare {
+					LogDebug("HTTP", "Cloudflare detected, retrying with Chrome TLS fingerprint...")
+
+					// Clone request for retry
+					reqCopy := req.Clone(req.Context())
+					reqCopy.Header.Set("User-Agent", getRandomUserAgent())
+
+					// Retry with uTLS Chrome fingerprint
+					return cloudflareBypassClient.Do(reqCopy)
+				}
+			}
+
+			// Not Cloudflare, return original response (recreate body)
+			return &http.Response{
+				Status:     resp.Status,
+				StatusCode: resp.StatusCode,
+				Header:     resp.Header,
+				Body:       io.NopCloser(strings.NewReader(string(body))),
+			}, nil
+		}
+		return resp, nil
+	}
+
+	// Check if error might be TLS-related (Cloudflare blocking)
+	errStr := strings.ToLower(err.Error())
+	tlsRelated := strings.Contains(errStr, "tls") ||
+		strings.Contains(errStr, "handshake") ||
+		strings.Contains(errStr, "certificate") ||
+		strings.Contains(errStr, "connection reset")
+
+	if tlsRelated {
+		LogDebug("HTTP", "TLS error detected, retrying with Chrome TLS fingerprint: %v", err)
+
+		// Clone request for retry
+		reqCopy := req.Clone(req.Context())
+		reqCopy.Header.Set("User-Agent", getRandomUserAgent())
+
+		// Retry with uTLS Chrome fingerprint
+		return cloudflareBypassClient.Do(reqCopy)
+	}
+
+	CheckAndLogISPBlocking(err, req.URL.String(), "HTTP")
+	return nil, err
+}

go_backend/idhs.go

@@ -0,0 +1,189 @@
+package gobackend
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+)
+
+// IDHSClient is a client for I Don't Have Spotify API
+// Used as fallback when SongLink fails or is rate limited
+type IDHSClient struct {
+	client *http.Client
+}
+
+var (
+	globalIDHSClient *IDHSClient
+	idhsClientOnce   sync.Once
+	idhsRateLimiter  = NewRateLimiter(8, time.Minute) // 8 req/min (below 10 limit)
+)
+
+// IDHSSearchRequest represents the request body for IDHS API
+type IDHSSearchRequest struct {
+	Link     string   `json:"link"`
+	Adapters []string `json:"adapters,omitempty"`
+}
+
+// IDHSSearchResponse represents the response from IDHS API
+type IDHSSearchResponse struct {
+	ID            string     `json:"id"`
+	Type          string     `json:"type"` // song, album, artist, podcast, show
+	Title         string     `json:"title"`
+	Description   string     `json:"description"`
+	Image         string     `json:"image,omitempty"`
+	Audio         string     `json:"audio,omitempty"`
+	Source        string     `json:"source"`
+	UniversalLink string     `json:"universalLink"`
+	Links         []IDHSLink `json:"links"`
+}
+
+// IDHSLink represents a link to a streaming platform
+type IDHSLink struct {
+	Type         string `json:"type"` // spotify, youTube, appleMusic, deezer, soundCloud, tidal
+	URL          string `json:"url"`
+	IsVerified   bool   `json:"isVerified,omitempty"`
+	NotAvailable bool   `json:"notAvailable,omitempty"`
+}
+
+// NewIDHSClient creates a new IDHS client
+func NewIDHSClient() *IDHSClient {
+	idhsClientOnce.Do(func() {
+		globalIDHSClient = &IDHSClient{
+			client: NewHTTPClientWithTimeout(15 * time.Second),
+		}
+	})
+	return globalIDHSClient
+}
+
+// Search converts a music link to links on other platforms
+func (c *IDHSClient) Search(link string, adapters []string) (*IDHSSearchResponse, error) {
+	idhsRateLimiter.WaitForSlot()
+
+	reqBody := IDHSSearchRequest{
+		Link:     link,
+		Adapters: adapters,
+	}
+
+	jsonBody, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal request: %w", err)
+	}
+
+	req, err := http.NewRequest("POST", "https://idonthavespotify.sjdonado.com/api/search?v=1", bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", getRandomUserAgent())
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == 400 {
+		return nil, fmt.Errorf("invalid link or missing parameters")
+	}
+	if resp.StatusCode == 429 {
+		return nil, fmt.Errorf("IDHS rate limit exceeded")
+	}
+	if resp.StatusCode == 500 {
+		return nil, fmt.Errorf("IDHS processing failed")
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("IDHS API returned status %d", resp.StatusCode)
+	}
+
+	body, err := ReadResponseBody(resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var result IDHSSearchResponse
+	if err := json.Unmarshal(body, &result); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	return &result, nil
+}
+
+// GetAvailabilityFromSpotify checks track availability using IDHS as fallback
+func (c *IDHSClient) GetAvailabilityFromSpotify(spotifyTrackID string) (*TrackAvailability, error) {
+	spotifyURL := fmt.Sprintf("https://open.spotify.com/track/%s", spotifyTrackID)
+
+	// Request only the platforms we need
+	adapters := []string{"tidal", "deezer"}
+
+	result, err := c.Search(spotifyURL, adapters)
+	if err != nil {
+		return nil, err
+	}
+
+	availability := &TrackAvailability{
+		SpotifyID: spotifyTrackID,
+	}
+
+	for _, link := range result.Links {
+		if link.NotAvailable {
+			continue
+		}
+
+		switch strings.ToLower(link.Type) {
+		case "tidal":
+			availability.Tidal = true
+			availability.TidalURL = link.URL
+		case "deezer":
+			availability.Deezer = true
+			availability.DeezerURL = link.URL
+			availability.DeezerID = extractDeezerIDFromURL(link.URL)
+		}
+	}
+
+	LogDebug("IDHS", "Availability from Spotify %s: Tidal=%v, Deezer=%v",
+		spotifyTrackID, availability.Tidal, availability.Deezer)
+
+	return availability, nil
+}
+
+// GetAvailabilityFromDeezer checks track availability using IDHS
+func (c *IDHSClient) GetAvailabilityFromDeezer(deezerTrackID string) (*TrackAvailability, error) {
+	deezerURL := fmt.Sprintf("https://www.deezer.com/track/%s", deezerTrackID)
+
+	// Request only the platforms we need
+	adapters := []string{"spotify", "tidal"}
+
+	result, err := c.Search(deezerURL, adapters)
+	if err != nil {
+		return nil, err
+	}
+
+	availability := &TrackAvailability{
+		Deezer:   true,
+		DeezerID: deezerTrackID,
+	}
+
+	for _, link := range result.Links {
+		if link.NotAvailable {
+			continue
+		}
+
+		switch strings.ToLower(link.Type) {
+		case "spotify":
+			availability.SpotifyID = extractSpotifyIDFromURL(link.URL)
+		case "tidal":
+			availability.Tidal = true
+			availability.TidalURL = link.URL
+		}
+	}
+
+	LogDebug("IDHS", "Availability from Deezer %s: Spotify=%s, Tidal=%v",
+		deezerTrackID, availability.SpotifyID, availability.Tidal)
+
+	return availability, nil
+}

go_backend/logbuffer.go

@@ -8,7 +8,6 @@ import (
 	"time"
 )
 
-// LogEntry represents a single log entry
 type LogEntry struct {
 	Timestamp string `json:"timestamp"`
 	Level     string `json:"level"`
@@ -16,12 +15,11 @@ type LogEntry struct {
 	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)
+	loggingEnabled bool
 }
 
 var (
@@ -41,7 +39,6 @@ func GetLogBuffer() *LogBuffer {
 	return globalLogBuffer
 }
 
-// SetLoggingEnabled enables or disables logging
 func (lb *LogBuffer) SetLoggingEnabled(enabled bool) {
 	lb.mu.Lock()
 	defer lb.mu.Unlock()
@@ -55,12 +52,10 @@ func (lb *LogBuffer) IsLoggingEnabled() bool {
 	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
 	}
@@ -73,12 +68,10 @@ func (lb *LogBuffer) Add(level, tag, message string) {
 	}
 
 	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)
 }
 
@@ -91,7 +84,6 @@ func (lb *LogBuffer) GetAll() string {
 	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()
@@ -158,11 +150,11 @@ func GoLog(format string, args ...interface{}) {
 
 	// Determine level from message content
 	msgLower := strings.ToLower(message)
-	if strings.Contains(msgLower, "error") || strings.Contains(msgLower, "failed") || strings.HasPrefix(message, "✗") {
+	if strings.Contains(msgLower, "error") || strings.Contains(msgLower, "failed") {
 		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") {
+	} else if 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"

go_backend/lyrics.go

@@ -3,14 +3,93 @@ package gobackend
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"net/http"
 	"net/url"
+	"os"
+	"path/filepath"
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
+const (
+	lyricsCacheTTL       = 24 * time.Hour
+	durationToleranceSec = 10.0
+)
+
+type lyricsCacheEntry struct {
+	response  *LyricsResponse
+	expiresAt time.Time
+}
+
+type lyricsCache struct {
+	mu    sync.RWMutex
+	cache map[string]*lyricsCacheEntry
+}
+
+var globalLyricsCache = &lyricsCache{
+	cache: make(map[string]*lyricsCacheEntry),
+}
+
+func (c *lyricsCache) generateKey(artist, track string, durationSec float64) string {
+	normalizedArtist := strings.ToLower(strings.TrimSpace(artist))
+	normalizedTrack := strings.ToLower(strings.TrimSpace(track))
+	roundedDuration := math.Round(durationSec/10) * 10
+	return fmt.Sprintf("%s|%s|%.0f", normalizedArtist, normalizedTrack, roundedDuration)
+}
+
+func (c *lyricsCache) Get(artist, track string, durationSec float64) (*LyricsResponse, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	key := c.generateKey(artist, track, durationSec)
+	entry, exists := c.cache[key]
+	if !exists {
+		return nil, false
+	}
+
+	if time.Now().After(entry.expiresAt) {
+		return nil, false
+	}
+
+	return entry.response, true
+}
+
+func (c *lyricsCache) Set(artist, track string, durationSec float64, response *LyricsResponse) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	key := c.generateKey(artist, track, durationSec)
+	c.cache[key] = &lyricsCacheEntry{
+		response:  response,
+		expiresAt: time.Now().Add(lyricsCacheTTL),
+	}
+}
+
+func (c *lyricsCache) CleanExpired() int {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	now := time.Now()
+	cleaned := 0
+	for key, entry := range c.cache {
+		if now.After(entry.expiresAt) {
+			delete(c.cache, key)
+			cleaned++
+		}
+	}
+	return cleaned
+}
+
+func (c *lyricsCache) Size() int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return len(c.cache)
+}
+
 type LRCLibResponse struct {
 	ID           int     `json:"id"`
 	Name         string  `json:"name"`
@@ -44,9 +123,7 @@ type LyricsClient struct {
 
 func NewLyricsClient() *LyricsClient {
 	return &LyricsClient{
-		httpClient: &http.Client{
+		httpClient: NewHTTPClientWithTimeout(15 * time.Second),
-			Timeout: 15 * time.Second,
-		},
 	}
 }
 
@@ -86,7 +163,7 @@ func (c *LyricsClient) FetchLyricsWithMetadata(artist, track string) (*LyricsRes
 	return c.parseLRCLibResponse(&lrcResp), nil
 }
 
-func (c *LyricsClient) FetchLyricsFromLRCLibSearch(query string) (*LyricsResponse, error) {
+func (c *LyricsClient) FetchLyricsFromLRCLibSearch(query string, durationSec float64) (*LyricsResponse, error) {
 	baseURL := "https://lrclib.net/api/search"
 	params := url.Values{}
 	params.Set("q", query)
@@ -118,6 +195,11 @@ func (c *LyricsClient) FetchLyricsFromLRCLibSearch(query string) (*LyricsRespons
 		return nil, fmt.Errorf("no lyrics found")
 	}
 
+	bestMatch := c.findBestMatch(results, durationSec)
+	if bestMatch != nil {
+		return c.parseLRCLibResponse(bestMatch), nil
+	}
+
 	for _, result := range results {
 		if result.SyncedLyrics != "" {
 			return c.parseLRCLibResponse(&result), nil
@@ -127,38 +209,92 @@ func (c *LyricsClient) FetchLyricsFromLRCLibSearch(query string) (*LyricsRespons
 	return c.parseLRCLibResponse(&results[0]), nil
 }
 
-func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName string) (*LyricsResponse, error) {
+func (c *LyricsClient) findBestMatch(results []LRCLibResponse, targetDurationSec float64) *LRCLibResponse {
-	// Strategy 1: Direct match with artist and track name
+	var bestSynced *LRCLibResponse
-	lyrics, err := c.FetchLyricsWithMetadata(artistName, trackName)
+	var bestPlain *LRCLibResponse
-	if err == nil && lyrics != nil && len(lyrics.Lines) > 0 {
+
+	for i := range results {
+		result := &results[i]
+
+		durationMatches := targetDurationSec == 0 || c.durationMatches(result.Duration, targetDurationSec)
+
+		if durationMatches {
+			if result.SyncedLyrics != "" && bestSynced == nil {
+				bestSynced = result
+			} else if result.PlainLyrics != "" && bestPlain == nil {
+				bestPlain = result
+			}
+		}
+	}
+
+	if bestSynced != nil {
+		return bestSynced
+	}
+	return bestPlain
+}
+
+func (c *LyricsClient) durationMatches(lrcDuration, targetDuration float64) bool {
+	diff := math.Abs(lrcDuration - targetDuration)
+	return diff <= durationToleranceSec
+}
+
+func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName string, durationSec float64) (*LyricsResponse, error) {
+	primaryArtist := normalizeArtistName(artistName)
+
+	if cached, found := globalLyricsCache.Get(artistName, trackName, durationSec); found {
+		fmt.Printf("[Lyrics] Cache hit for: %s - %s\n", artistName, trackName)
+		cachedCopy := *cached
+		cachedCopy.Source = cached.Source + " (cached)"
+		return &cachedCopy, nil
+	}
+
+	var lyrics *LyricsResponse
+	var err error
+
+	isValidResult := func(l *LyricsResponse) bool {
+		return l != nil && (len(l.Lines) > 0 || l.Instrumental)
+	}
+
+	lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, trackName)
+	if err == nil && isValidResult(lyrics) {
 		lyrics.Source = "LRCLIB"
+		globalLyricsCache.Set(artistName, trackName, durationSec, lyrics)
 		return lyrics, nil
 	}
 
-	// Strategy 2: Try with simplified track name
+	if primaryArtist != artistName {
-	simplifiedTrack := simplifyTrackName(trackName)
+		lyrics, err = c.FetchLyricsWithMetadata(artistName, trackName)
-	if simplifiedTrack != trackName {
+		if err == nil && isValidResult(lyrics) {
-		lyrics, err = c.FetchLyricsWithMetadata(artistName, simplifiedTrack)
+			lyrics.Source = "LRCLIB"
-		if err == nil && lyrics != nil && len(lyrics.Lines) > 0 {
+			globalLyricsCache.Set(artistName, trackName, durationSec, lyrics)
-			lyrics.Source = "LRCLIB (simplified)"
 			return lyrics, nil
 		}
 	}
 
-	// Strategy 3: Search with full query
+	simplifiedTrack := simplifyTrackName(trackName)
-	query := artistName + " " + trackName
+	if simplifiedTrack != trackName {
-	lyrics, err = c.FetchLyricsFromLRCLibSearch(query)
+		lyrics, err = c.FetchLyricsWithMetadata(primaryArtist, simplifiedTrack)
-	if err == nil && lyrics != nil && len(lyrics.Lines) > 0 {
+		if err == nil && isValidResult(lyrics) {
+			lyrics.Source = "LRCLIB (simplified)"
+			globalLyricsCache.Set(artistName, trackName, durationSec, lyrics)
+			return lyrics, nil
+		}
+	}
+
+	query := primaryArtist + " " + trackName
+	lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
+	if err == nil && isValidResult(lyrics) {
 		lyrics.Source = "LRCLIB Search"
+		globalLyricsCache.Set(artistName, trackName, durationSec, lyrics)
 		return lyrics, nil
 	}
 
-	// Strategy 4: Search with simplified query
 	if simplifiedTrack != trackName {
-		query = artistName + " " + simplifiedTrack
+		query = primaryArtist + " " + simplifiedTrack
-		lyrics, err = c.FetchLyricsFromLRCLibSearch(query)
+		lyrics, err = c.FetchLyricsFromLRCLibSearch(query, durationSec)
-		if err == nil && lyrics != nil && len(lyrics.Lines) > 0 {
+		if err == nil && isValidResult(lyrics) {
 			lyrics.Source = "LRCLIB Search (simplified)"
+			globalLyricsCache.Set(artistName, trackName, durationSec, lyrics)
 			return lyrics, nil
 		}
 	}
@@ -248,35 +384,6 @@ 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
-// Kept for potential future use
-// func convertToLRC(lyrics *LyricsResponse) string {
-// 	if lyrics == nil || len(lyrics.Lines) == 0 {
-// 		return ""
-// 	}
-//
-// 	var builder strings.Builder
-//
-// 	if lyrics.SyncType == "LINE_SYNCED" {
-// 		for _, line := range lyrics.Lines {
-// 			timestamp := msToLRCTimestamp(line.StartTimeMs)
-// 			builder.WriteString(timestamp)
-// 			builder.WriteString(line.Words)
-// 			builder.WriteString("\n")
-// 		}
-// 	} else {
-// 		for _, line := range lyrics.Lines {
-// 			builder.WriteString(line.Words)
-// 			builder.WriteString("\n")
-// 		}
-// 	}
-//
-// 	return builder.String()
-// }
-
-// 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 ""
@@ -284,13 +391,11 @@ func convertToLRCWithMetadata(lyrics *LyricsResponse, trackName, artistName stri
 
 	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 == "" {
@@ -339,3 +444,36 @@ func simplifyTrackName(name string) string {
 
 	return strings.TrimSpace(result)
 }
+
+func normalizeArtistName(name string) string {
+	separators := []string{", ", "; ", " & ", " feat. ", " ft. ", " featuring ", " with "}
+
+	result := name
+	for _, sep := range separators {
+		if idx := strings.Index(strings.ToLower(result), strings.ToLower(sep)); idx > 0 {
+			result = result[:idx]
+			break
+		}
+	}
+
+	return strings.TrimSpace(result)
+}
+
+func SaveLRCFile(audioFilePath, lrcContent string) (string, error) {
+	if lrcContent == "" {
+		return "", fmt.Errorf("empty LRC content")
+	}
+
+	dir := filepath.Dir(audioFilePath)
+	ext := filepath.Ext(audioFilePath)
+	baseName := strings.TrimSuffix(filepath.Base(audioFilePath), ext)
+
+	lrcFilePath := filepath.Join(dir, baseName+".lrc")
+
+	if err := os.WriteFile(lrcFilePath, []byte(lrcContent), 0644); err != nil {
+		return "", fmt.Errorf("failed to write LRC file: %w", err)
+	}
+
+	GoLog("[Lyrics] Saved LRC file: %s\n", lrcFilePath)
+	return lrcFilePath, nil
+}

go_backend/metadata.go

@@ -1,7 +1,10 @@
 package gobackend
 
 import (
+	"bytes"
+	"encoding/binary"
 	"fmt"
+	"io"
 	"os"
 	"strconv"
 	"strings"
@@ -11,7 +14,6 @@ import (
 	"github.com/go-flac/go-flac"
 )
 
-// Metadata represents track metadata for embedding
 type Metadata struct {
 	Title       string
 	Artist      string
@@ -24,16 +26,17 @@ type Metadata struct {
 	ISRC        string
 	Description string
 	Lyrics      string
+	Genre       string
+	Label       string
+	Copyright   string
 }
 
-// EmbedMetadata embeds metadata into a FLAC file
 func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
 		return fmt.Errorf("failed to parse FLAC file: %w", err)
 	}
 
-	// Find or create vorbis comment block
 	var cmtIdx int = -1
 	var cmt *flacvorbis.MetaDataBlockVorbisComment
 
@@ -52,7 +55,6 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 		cmt = flacvorbis.New()
 	}
 
-	// Set metadata fields
 	setComment(cmt, "TITLE", metadata.Title)
 	setComment(cmt, "ARTIST", metadata.Artist)
 	setComment(cmt, "ALBUM", metadata.Album)
@@ -84,7 +86,18 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 		setComment(cmt, "UNSYNCEDLYRICS", metadata.Lyrics)
 	}
 
-	// Update or add vorbis comment block
+	if metadata.Genre != "" {
+		setComment(cmt, "GENRE", metadata.Genre)
+	}
+
+	if metadata.Label != "" {
+		setComment(cmt, "ORGANIZATION", metadata.Label)
+	}
+
+	if metadata.Copyright != "" {
+		setComment(cmt, "COPYRIGHT", metadata.Copyright)
+	}
+
 	cmtBlock := cmt.Marshal()
 	if cmtIdx >= 0 {
 		f.Meta[cmtIdx] = &cmtBlock
@@ -92,14 +105,12 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 		f.Meta = append(f.Meta, &cmtBlock)
 	}
 
-	// Add cover art if provided
 	if coverPath != "" {
 		if fileExists(coverPath) {
 			coverData, err := os.ReadFile(coverPath)
 			if err != nil {
 				fmt.Printf("[Metadata] Warning: Failed to read cover file %s: %v\n", coverPath, err)
 			} else {
-				// Remove existing picture blocks first (like PC version)
 				for i := len(f.Meta) - 1; i >= 0; i-- {
 					if f.Meta[i].Type == flac.Picture {
 						f.Meta = append(f.Meta[:i], f.Meta[i+1:]...)
@@ -125,19 +136,15 @@ func EmbedMetadata(filePath string, metadata Metadata, coverPath string) error {
 		}
 	}
 
-	// Save file
 	return f.Save(filePath)
 }
 
-// EmbedMetadataWithCoverData embeds metadata into a FLAC file with cover data as bytes
-// This avoids file permission issues on Android by not requiring a temp file
 func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []byte) error {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
 		return fmt.Errorf("failed to parse FLAC file: %w", err)
 	}
 
-	// Find or create vorbis comment block
 	var cmtIdx int = -1
 	var cmt *flacvorbis.MetaDataBlockVorbisComment
 
@@ -156,7 +163,6 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 		cmt = flacvorbis.New()
 	}
 
-	// Set metadata fields
 	setComment(cmt, "TITLE", metadata.Title)
 	setComment(cmt, "ARTIST", metadata.Artist)
 	setComment(cmt, "ALBUM", metadata.Album)
@@ -188,7 +194,18 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 		setComment(cmt, "UNSYNCEDLYRICS", metadata.Lyrics)
 	}
 
-	// Update or add vorbis comment block
+	if metadata.Genre != "" {
+		setComment(cmt, "GENRE", metadata.Genre)
+	}
+
+	if metadata.Label != "" {
+		setComment(cmt, "ORGANIZATION", metadata.Label)
+	}
+
+	if metadata.Copyright != "" {
+		setComment(cmt, "COPYRIGHT", metadata.Copyright)
+	}
+
 	cmtBlock := cmt.Marshal()
 	if cmtIdx >= 0 {
 		f.Meta[cmtIdx] = &cmtBlock
@@ -196,9 +213,7 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 		f.Meta = append(f.Meta, &cmtBlock)
 	}
 
-	// Add cover art if provided
 	if len(coverData) > 0 {
-		// Remove existing picture blocks first
 		for i := len(f.Meta) - 1; i >= 0; i-- {
 			if f.Meta[i].Type == flac.Picture {
 				f.Meta = append(f.Meta[:i], f.Meta[i+1:]...)
@@ -220,11 +235,9 @@ func EmbedMetadataWithCoverData(filePath string, metadata Metadata, coverData []
 		}
 	}
 
-	// Save file
 	return f.Save(filePath)
 }
 
-// ReadMetadata reads metadata from a FLAC file
 func ReadMetadata(filePath string) (*Metadata, error) {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -257,7 +270,6 @@ 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 != "" {
@@ -269,7 +281,6 @@ func ReadMetadata(filePath string) (*Metadata, error) {
 			if discNum != "" {
 				fmt.Sscanf(discNum, "%d", &metadata.DiscNumber)
 			}
-			// Also try DISC variant
 			if metadata.DiscNumber == 0 {
 				discNum = getComment(cmt, "DISC")
 				if discNum != "" {
@@ -277,7 +288,6 @@ func ReadMetadata(filePath string) (*Metadata, error) {
 				}
 			}
 
-			// Try DATE variants
 			if metadata.Date == "" {
 				metadata.Date = getComment(cmt, "YEAR")
 			}
@@ -293,7 +303,6 @@ func setComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key, value string) {
 	if value == "" {
 		return
 	}
-	// Remove existing (case-insensitive comparison for Vorbis comments)
 	keyUpper := strings.ToUpper(key)
 	for i := len(cmt.Comments) - 1; i >= 0; i-- {
 		comment := cmt.Comments[i]
@@ -305,7 +314,6 @@ func setComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key, value string) {
 			}
 		}
 	}
-	// Add new
 	cmt.Comments = append(cmt.Comments, key+"="+value)
 }
 
@@ -313,7 +321,6 @@ func getComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key string) string {
 	keyUpper := strings.ToUpper(key) + "="
 	for _, comment := range cmt.Comments {
 		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:]
@@ -323,13 +330,44 @@ func getComment(cmt *flacvorbis.MetaDataBlockVorbisComment, key string) string {
 	return ""
 }
 
-// fileExists checks if a file exists
 func fileExists(path string) bool {
 	_, err := os.Stat(path)
 	return err == nil
 }
 
-// EmbedLyrics embeds lyrics into a FLAC file as a separate operation
+func ExtractCoverArt(filePath string) ([]byte, error) {
+	f, err := flac.ParseFile(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse FLAC file: %w", err)
+	}
+
+	for _, meta := range f.Meta {
+		if meta.Type == flac.Picture {
+			pic, err := flacpicture.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				continue
+			}
+			if pic.PictureType == flacpicture.PictureTypeFrontCover && len(pic.ImageData) > 0 {
+				return pic.ImageData, nil
+			}
+		}
+	}
+
+	for _, meta := range f.Meta {
+		if meta.Type == flac.Picture {
+			pic, err := flacpicture.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				continue
+			}
+			if len(pic.ImageData) > 0 {
+				return pic.ImageData, nil
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("no cover art found in file")
+}
+
 func EmbedLyrics(filePath string, lyrics string) error {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -367,7 +405,51 @@ func EmbedLyrics(filePath string, lyrics string) error {
 	return f.Save(filePath)
 }
 
-// ExtractLyrics extracts embedded lyrics from a FLAC file
+func EmbedGenreLabel(filePath string, genre, label string) error {
+	if genre == "" && label == "" {
+		return nil
+	}
+
+	f, err := flac.ParseFile(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to parse FLAC file: %w", err)
+	}
+
+	var cmtIdx int = -1
+	var cmt *flacvorbis.MetaDataBlockVorbisComment
+
+	for idx, meta := range f.Meta {
+		if meta.Type == flac.VorbisComment {
+			cmtIdx = idx
+			cmt, err = flacvorbis.ParseFromMetaDataBlock(*meta)
+			if err != nil {
+				return fmt.Errorf("failed to parse vorbis comment: %w", err)
+			}
+			break
+		}
+	}
+
+	if cmt == nil {
+		cmt = flacvorbis.New()
+	}
+
+	if genre != "" {
+		setComment(cmt, "GENRE", genre)
+	}
+	if label != "" {
+		setComment(cmt, "ORGANIZATION", label)
+	}
+
+	cmtBlock := cmt.Marshal()
+	if cmtIdx >= 0 {
+		f.Meta[cmtIdx] = &cmtBlock
+	} else {
+		f.Meta = append(f.Meta, &cmtBlock)
+	}
+
+	return f.Save(filePath)
+}
+
 func ExtractLyrics(filePath string) (string, error) {
 	f, err := flac.ParseFile(filePath)
 	if err != nil {
@@ -381,13 +463,11 @@ func ExtractLyrics(filePath string) (string, error) {
 				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
@@ -398,16 +478,12 @@ func ExtractLyrics(filePath string) (string, error) {
 	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 {
@@ -415,16 +491,12 @@ func GetAudioQuality(filePath string) (AudioQuality, error) {
 	}
 	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)
@@ -435,19 +507,15 @@ func GetAudioQuality(filePath string) (AudioQuality, error) {
 			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 |
@@ -461,362 +529,194 @@ func GetAudioQuality(filePath string) (AudioQuality, error) {
 		}, nil
 	}
 
-	// Check if it's an M4A/MP4 file (starts with size + "ftyp")
+	file.Seek(0, 0)
-	// 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()
-		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(uint32(data[moovPos])<<24 | uint32(data[moovPos+1])<<16 | uint32(data[moovPos+2])<<8 | uint32(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(uint32(data[udtaPos])<<24 | uint32(data[udtaPos+1])<<16 | uint32(data[udtaPos+2])<<8 | uint32(data[udtaPos+3]))
-		metaPos := findAtom(data, "meta", udtaPos+8)
-
-		if metaPos >= 0 && metaPos < udtaPos+udtaSize {
-			// Replace existing meta atom
-			metaSize := int(uint32(data[metaPos])<<24 | uint32(data[metaPos+1])<<16 | uint32(data[metaPos+2])<<8 | uint32(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(uint32(data[i])<<24 | uint32(data[i+1])<<16 | uint32(data[i+2])<<8 | uint32(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)
+	f, err := os.Open(filePath)
 	if err != nil {
-		return AudioQuality{}, fmt.Errorf("failed to read M4A file: %w", err)
+		return AudioQuality{}, fmt.Errorf("failed to open M4A file: %w", err)
 	}
+	defer f.Close()
 
-	// Find moov -> trak -> mdia -> minf -> stbl -> stsd
+	info, err := f.Stat()
-	moovPos := findAtom(data, "moov", 0)
+	if err != nil {
-	if moovPos < 0 {
+		return AudioQuality{}, fmt.Errorf("failed to stat M4A file: %w", err)
+	}
+	fileSize := info.Size()
+
+	moovHeader, moovFound, err := findAtomInRange(f, 0, fileSize, "moov", fileSize)
+	if err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to find moov atom: %w", err)
+	}
+	if !moovFound {
 		return AudioQuality{}, fmt.Errorf("moov atom not found")
 	}
 
-	// Search for mp4a or alac atom which contains audio info
+	moovStart := moovHeader.offset
-	// This is a simplified search - real implementation would traverse the atom tree
+	moovEnd := moovHeader.offset + moovHeader.size
-	for i := moovPos; i < len(data)-20; i++ {
+
-		if string(data[i:i+4]) == "mp4a" || string(data[i:i+4]) == "alac" {
+	sampleOffset, atomType, err := findAudioSampleEntry(f, moovStart, moovEnd, fileSize)
-			// Sample rate is at offset 22-23 from atom start (16-bit big-endian)
+	if err != nil {
-			if i+24 < len(data) {
+		return AudioQuality{}, err
-				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")
+	buf := make([]byte, 24)
+	if _, err := f.ReadAt(buf, sampleOffset); err != nil {
+		return AudioQuality{}, fmt.Errorf("failed to read audio sample entry: %w", err)
+	}
+
+	sampleRate := int(buf[22])<<8 | int(buf[23])
+	bitDepth := 16
+	if atomType == "alac" {
+		bitDepth = 24
+	}
+
+	return AudioQuality{BitDepth: bitDepth, SampleRate: sampleRate}, nil
+}
+
+type atomHeader struct {
+	offset     int64
+	size       int64
+	headerSize int64
+	typ        string
+}
+
+func readAtomHeaderAt(f *os.File, offset, fileSize int64) (atomHeader, error) {
+	if offset+8 > fileSize {
+		return atomHeader{}, io.ErrUnexpectedEOF
+	}
+
+	headerBuf := make([]byte, 8)
+	if _, err := f.ReadAt(headerBuf, offset); err != nil {
+		return atomHeader{}, err
+	}
+
+	size32 := binary.BigEndian.Uint32(headerBuf[0:4])
+	typ := string(headerBuf[4:8])
+
+	if size32 == 1 {
+		if offset+16 > fileSize {
+			return atomHeader{}, io.ErrUnexpectedEOF
+		}
+		extBuf := make([]byte, 8)
+		if _, err := f.ReadAt(extBuf, offset+8); err != nil {
+			return atomHeader{}, err
+		}
+		size64 := binary.BigEndian.Uint64(extBuf)
+		return atomHeader{offset: offset, size: int64(size64), headerSize: 16, typ: typ}, nil
+	}
+
+	return atomHeader{offset: offset, size: int64(size32), headerSize: 8, typ: typ}, nil
+}
+
+func findAtomInRange(f *os.File, start, size int64, target string, fileSize int64) (atomHeader, bool, error) {
+	if size <= 0 {
+		return atomHeader{}, false, nil
+	}
+
+	end := start + size
+	pos := start
+
+	for pos+8 <= end {
+		header, err := readAtomHeaderAt(f, pos, fileSize)
+		if err != nil {
+			return atomHeader{}, false, err
+		}
+
+		atomSize := header.size
+		if atomSize == 0 {
+			atomSize = end - pos
+		}
+
+		if atomSize < header.headerSize {
+			return atomHeader{}, false, fmt.Errorf("invalid atom size for %s", header.typ)
+		}
+
+		header.size = atomSize
+		if header.typ == target {
+			return header, true, nil
+		}
+
+		pos += atomSize
+	}
+
+	return atomHeader{}, false, nil
+}
+
+func findAudioSampleEntry(f *os.File, start, end, fileSize int64) (int64, string, error) {
+	const chunkSize = 64 * 1024
+	patternMP4A := []byte("mp4a")
+	patternALAC := []byte("alac")
+
+	var tail []byte
+	readPos := start
+
+	for readPos < end {
+		toRead := end - readPos
+		if toRead > chunkSize {
+			toRead = chunkSize
+		}
+
+		buf := make([]byte, toRead)
+		n, err := f.ReadAt(buf, readPos)
+		if err != nil && err != io.EOF {
+			return 0, "", fmt.Errorf("failed to read M4A atom data: %w", err)
+		}
+		if n == 0 {
+			break
+		}
+
+		data := append(tail, buf[:n]...)
+		mp4aIdx := bytes.Index(data, patternMP4A)
+		alacIdx := bytes.Index(data, patternALAC)
+
+		bestIdx := -1
+		bestType := ""
+		switch {
+		case mp4aIdx >= 0 && alacIdx >= 0:
+			if mp4aIdx <= alacIdx {
+				bestIdx = mp4aIdx
+				bestType = "mp4a"
+			} else {
+				bestIdx = alacIdx
+				bestType = "alac"
+			}
+		case mp4aIdx >= 0:
+			bestIdx = mp4aIdx
+			bestType = "mp4a"
+		case alacIdx >= 0:
+			bestIdx = alacIdx
+			bestType = "alac"
+		}
+
+		if bestIdx >= 0 {
+			absolute := readPos - int64(len(tail)) + int64(bestIdx)
+			if absolute+24 > fileSize {
+				return 0, "", fmt.Errorf("audio info not found in M4A file")
+			}
+			return absolute, bestType, nil
+		}
+
+		if len(data) >= 3 {
+			tail = append([]byte{}, data[len(data)-3:]...)
+		} else {
+			tail = append([]byte{}, data...)
+		}
+
+		readPos += int64(n)
+	}
+
+	return 0, "", fmt.Errorf("audio info not found in M4A file")
 }

go_backend/mobile_deps.go

@@ -0,0 +1,10 @@
+// mobile_deps.go
+// This file ensures gomobile dependencies are not removed by go mod tidy.
+// These packages are required by gomobile bind but not directly imported in code.
+
+package gobackend
+
+import (
+	// Required for gomobile bind to work
+	_ "golang.org/x/mobile/bind"
+)

go_backend/parallel.go

@@ -6,11 +6,6 @@ import (
 	"time"
 )
 
-// ========================================
-// ISRC to Track ID Cache
-// ========================================
-
-// TrackIDCacheEntry holds cached track ID with metadata
 type TrackIDCacheEntry struct {
 	TidalTrackID  int64
 	QobuzTrackID  int64
@@ -18,11 +13,12 @@ type TrackIDCacheEntry struct {
 	ExpiresAt     time.Time
 }
 
-// TrackIDCache caches ISRC to track ID mappings
 type TrackIDCache struct {
-	cache map[string]*TrackIDCacheEntry
+	cache           map[string]*TrackIDCacheEntry
-	mu    sync.RWMutex
+	mu              sync.RWMutex
-	ttl   time.Duration
+	ttl             time.Duration
+	lastCleanup     time.Time
+	cleanupInterval time.Duration
 }
 
 var (
@@ -30,30 +26,48 @@ var (
 	trackIDCacheOnce   sync.Once
 )
 
-// GetTrackIDCache returns the global track ID cache
 func GetTrackIDCache() *TrackIDCache {
 	trackIDCacheOnce.Do(func() {
 		globalTrackIDCache = &TrackIDCache{
-			cache: make(map[string]*TrackIDCacheEntry),
+			cache:           make(map[string]*TrackIDCacheEntry),
-			ttl:   30 * time.Minute, // Cache for 30 minutes
+			ttl:             30 * time.Minute,
+			cleanupInterval: 5 * time.Minute,
 		}
 	})
 	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) {
+	if !exists {
+		c.mu.RUnlock()
 		return nil
 	}
-	return entry
+	expired := time.Now().After(entry.ExpiresAt)
+	c.mu.RUnlock()
+
+	if !expired {
+		return entry
+	}
+
+	c.mu.Lock()
+	entry, exists = c.cache[isrc]
+	if exists && time.Now().After(entry.ExpiresAt) {
+		delete(c.cache, isrc)
+	}
+	c.mu.Unlock()
+	return nil
+}
+
+func (c *TrackIDCache) pruneExpiredLocked(now time.Time) {
+	for key, entry := range c.cache {
+		if now.After(entry.ExpiresAt) {
+			delete(c.cache, key)
+		}
+	}
 }
 
-// SetTidal caches Tidal track ID for an ISRC
 func (c *TrackIDCache) SetTidal(isrc string, trackID int64) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -64,10 +78,15 @@ func (c *TrackIDCache) SetTidal(isrc string, trackID int64) {
 		c.cache[isrc] = entry
 	}
 	entry.TidalTrackID = trackID
-	entry.ExpiresAt = time.Now().Add(c.ttl)
+	now := time.Now()
+	entry.ExpiresAt = now.Add(c.ttl)
+
+	if c.cleanupInterval > 0 && (c.lastCleanup.IsZero() || now.Sub(c.lastCleanup) >= c.cleanupInterval) {
+		c.pruneExpiredLocked(now)
+		c.lastCleanup = now
+	}
 }
 
-// SetQobuz caches Qobuz track ID for an ISRC
 func (c *TrackIDCache) SetQobuz(isrc string, trackID int64) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -78,10 +97,15 @@ func (c *TrackIDCache) SetQobuz(isrc string, trackID int64) {
 		c.cache[isrc] = entry
 	}
 	entry.QobuzTrackID = trackID
-	entry.ExpiresAt = time.Now().Add(c.ttl)
+	now := time.Now()
+	entry.ExpiresAt = now.Add(c.ttl)
+
+	if c.cleanupInterval > 0 && (c.lastCleanup.IsZero() || now.Sub(c.lastCleanup) >= c.cleanupInterval) {
+		c.pruneExpiredLocked(now)
+		c.lastCleanup = now
+	}
 }
 
-// SetAmazon caches Amazon track ID for an ISRC
 func (c *TrackIDCache) SetAmazon(isrc string, trackID string) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -92,28 +116,27 @@ func (c *TrackIDCache) SetAmazon(isrc string, trackID string) {
 		c.cache[isrc] = entry
 	}
 	entry.AmazonTrackID = trackID
-	entry.ExpiresAt = time.Now().Add(c.ttl)
+	now := time.Now()
+	entry.ExpiresAt = now.Add(c.ttl)
+
+	if c.cleanupInterval > 0 && (c.lastCleanup.IsZero() || now.Sub(c.lastCleanup) >= c.cleanupInterval) {
+		c.pruneExpiredLocked(now)
+		c.lastCleanup = now
+	}
 }
 
-// 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
@@ -122,8 +145,6 @@ type ParallelDownloadResult struct {
 	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,
@@ -131,46 +152,38 @@ func FetchCoverAndLyricsParallel(
 	trackName string,
 	artistName string,
 	embedLyrics bool,
+	durationMs int64,
 ) *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)
+			durationSec := float64(durationMs) / 1000.0
+			lyrics, err := client.FetchLyricsAllSources(spotifyID, trackName, artistName, durationSec)
 			if err != nil {
 				result.LyricsErr = err
-				fmt.Printf("[Parallel] Lyrics fetch failed: %v\n", err)
 			} else if lyrics != nil && len(lyrics.Lines) > 0 {
 				result.LyricsData = lyrics
-				// 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")
 			}
 		}()
 	}
@@ -179,35 +192,25 @@ func FetchCoverAndLyricsParallel(
 	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)
+	SpotifyID  string
-	Service    string // "tidal", "qobuz", "amazon"
+	Service    string
 }
 
-// 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)
-	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
 		}
@@ -215,8 +218,8 @@ func PreWarmTrackCache(requests []PreWarmCacheRequest) {
 		wg.Add(1)
 		go func(r PreWarmCacheRequest) {
 			defer wg.Done()
-			semaphore <- struct{}{}        // Acquire
+			semaphore <- struct{}{}
-			defer func() { <-semaphore }() // Release
+			defer func() { <-semaphore }()
 
 			switch r.Service {
 			case "tidal":
@@ -230,7 +233,6 @@ func PreWarmTrackCache(requests []PreWarmCacheRequest) {
 	}
 
 	wg.Wait()
-	fmt.Printf("[Cache] Pre-warm complete. Cache size: %d\n", cache.Size())
 }
 
 func preWarmTidalCache(isrc, _, _ string) {
@@ -238,7 +240,6 @@ func preWarmTidalCache(isrc, _, _ string) {
 	track, err := downloader.SearchTrackByISRC(isrc)
 	if err == nil && track != nil {
 		GetTrackIDCache().SetTidal(isrc, track.ID)
-		fmt.Printf("[Cache] Cached Tidal ID for ISRC %s: %d\n", isrc, track.ID)
 	}
 }
 
@@ -247,43 +248,28 @@ func preWarmQobuzCache(isrc string) {
 	track, err := downloader.SearchTrackByISRC(isrc)
 	if err == nil && track != nil {
 		GetTrackIDCache().SetQobuz(isrc, track.ID)
-		fmt.Printf("[Cache] Cached Qobuz ID for ISRC %s: %d\n", isrc, track.ID)
 	}
 }
 
 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
+	go PreWarmTrackCache(requests)
 	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

@@ -6,8 +6,6 @@ import (
 	"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"`
@@ -15,21 +13,19 @@ 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"
+	Status        string  `json:"status"`
 }
 
-// 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
+	Progress      float64 `json:"progress"`
-	SpeedMBps     float64 `json:"speed_mbps"` // Download speed in MB/s
+	SpeedMBps     float64 `json:"speed_mbps"`
 	IsDownloading bool    `json:"is_downloading"`
-	Status        string  `json:"status"` // "downloading", "finalizing", "completed"
+	Status        string  `json:"status"`
 }
 
-// MultiProgress holds progress for multiple concurrent downloads
 type MultiProgress struct {
 	Items map[string]*ItemProgress `json:"items"`
 }
@@ -38,22 +34,18 @@ var (
 	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 from multi-progress system
-// Returns first active item's progress for backward compatibility
 func getProgress() DownloadProgress {
 	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
+			Progress:      item.Progress * 100,
 			BytesTotal:    item.BytesTotal,
 			BytesReceived: item.BytesReceived,
 			IsDownloading: item.IsDownloading,
@@ -64,7 +56,6 @@ func getProgress() DownloadProgress {
 	return DownloadProgress{}
 }
 
-// GetMultiProgress returns progress for all active downloads as JSON
 func GetMultiProgress() string {
 	multiMu.RLock()
 	defer multiMu.RUnlock()
@@ -76,7 +67,6 @@ func GetMultiProgress() string {
 	return string(jsonBytes)
 }
 
-// GetItemProgress returns progress for a specific item as JSON
 func GetItemProgress(itemID string) string {
 	multiMu.RLock()
 	defer multiMu.RUnlock()
@@ -88,7 +78,6 @@ func GetItemProgress(itemID string) string {
 	return "{}"
 }
 
-// StartItemProgress initializes progress tracking for an item
 func StartItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -103,7 +92,6 @@ func StartItemProgress(itemID string) {
 	}
 }
 
-// SetItemBytesTotal sets total bytes for an item
 func SetItemBytesTotal(itemID string, total int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -113,7 +101,6 @@ func SetItemBytesTotal(itemID string, total int64) {
 	}
 }
 
-// SetItemBytesReceived sets bytes received for an item
 func SetItemBytesReceived(itemID string, received int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -126,7 +113,6 @@ func SetItemBytesReceived(itemID string, received int64) {
 	}
 }
 
-// SetItemBytesReceivedWithSpeed sets bytes received and speed for an item
 func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps float64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -140,7 +126,6 @@ func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps floa
 	}
 }
 
-// CompleteItemProgress marks an item as complete
 func CompleteItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -152,7 +137,6 @@ func CompleteItemProgress(itemID string) {
 	}
 }
 
-// SetItemProgress sets progress for an item directly
 func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal int64) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -168,7 +152,6 @@ func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal
 	}
 }
 
-// SetItemFinalizing marks an item as finalizing (embedding metadata)
 func SetItemFinalizing(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -179,7 +162,6 @@ func SetItemFinalizing(itemID string) {
 	}
 }
 
-// RemoveItemProgress removes progress tracking for an item
 func RemoveItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -187,7 +169,6 @@ func RemoveItemProgress(itemID string) {
 	delete(multiProgress.Items, itemID)
 }
 
-// ClearAllItemProgress clears all item progress
 func ClearAllItemProgress() {
 	multiMu.Lock()
 	defer multiMu.Unlock()
@@ -195,7 +176,6 @@ func ClearAllItemProgress() {
 	multiProgress.Items = make(map[string]*ItemProgress)
 }
 
-// setDownloadDir sets the default download directory
 func setDownloadDir(path string) error {
 	downloadDirMu.Lock()
 	defer downloadDirMu.Unlock()
@@ -203,15 +183,6 @@ func setDownloadDir(path string) error {
 	return nil
 }
 
-// getDownloadDir returns the default download directory
-// Kept for potential future use
-// func getDownloadDir() string {
-// 	downloadDirMu.RLock()
-// 	defer downloadDirMu.RUnlock()
-// 	return downloadDir
-// }
-
-// ItemProgressWriter wraps io.Writer to track download progress for a specific item
 type ItemProgressWriter struct {
 	writer       interface{ Write([]byte) (int, error) }
 	itemID       string
@@ -224,7 +195,6 @@ type ItemProgressWriter struct {
 
 const progressUpdateThreshold = 64 * 1024 // Update progress every 64KB
 
-// NewItemProgressWriter creates a new progress writer for a specific item
 func NewItemProgressWriter(w interface{ Write([]byte) (int, error) }, itemID string) *ItemProgressWriter {
 	now := time.Now()
 	return &ItemProgressWriter{
@@ -238,18 +208,17 @@ func NewItemProgressWriter(w interface{ Write([]byte) (int, error) }, itemID str
 	}
 }
 
-// Write implements io.Writer with threshold-based progress updates and speed tracking
 func (pw *ItemProgressWriter) Write(p []byte) (int, error) {
+	if pw.itemID != "" && isDownloadCancelled(pw.itemID) {
+		return 0, ErrDownloadCancelled
+	}
 	n, err := pw.writer.Write(p)
 	if err != nil {
 		return n, err
 	}
 	pw.current += int64(n)
 
-	// 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

go_backend/qobuz.go

@@ -2,8 +2,10 @@ package gobackend
 
 import (
 	"bufio"
+	"context"
 	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -15,7 +17,6 @@ import (
 	"time"
 )
 
-// QobuzDownloader handles Qobuz downloads
 type QobuzDownloader struct {
 	client *http.Client
 	appID  string
@@ -23,12 +24,10 @@ type QobuzDownloader struct {
 }
 
 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"`
 	Title               string  `json:"title"`
@@ -49,37 +48,29 @@ type QobuzTrack struct {
 	} `json:"performer"`
 }
 
-// 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
 	}
 
-	// Split expected artists by common separators (comma, feat, ft., &, and)
-	// e.g., "RADWIMPS, Toko Miura" or "RADWIMPS feat. Toko Miura"
 	expectedArtists := qobuzSplitArtists(normExpected)
 	foundArtists := qobuzSplitArtists(normFound)
 
-	// Check if ANY expected artist matches ANY found artist
 	for _, exp := range expectedArtists {
 		for _, fnd := range foundArtists {
 			if exp == fnd {
 				return true
 			}
-			// Also check contains for partial matches
 			if strings.Contains(exp, fnd) || strings.Contains(fnd, exp) {
 				return true
 			}
-			// Check same words different order
 			if qobuzSameWordsUnordered(exp, fnd) {
 				GoLog("[Qobuz] Artist names have same words in different order: '%s' vs '%s'\n", exp, fnd)
 				return true
@@ -87,8 +78,6 @@ func qobuzArtistsMatch(expectedArtist, foundArtist string) bool {
 		}
 	}
 
-	// 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 {
@@ -99,9 +88,7 @@ func qobuzArtistsMatch(expectedArtist, foundArtist string) bool {
 	return false
 }
 
-// qobuzSplitArtists splits artist string by common separators
 func qobuzSplitArtists(artists string) []string {
-	// Replace common separators with a standard one
 	normalized := artists
 	normalized = strings.ReplaceAll(normalized, " feat. ", "|")
 	normalized = strings.ReplaceAll(normalized, " feat ", "|")
@@ -123,24 +110,19 @@ func qobuzSplitArtists(artists string) []string {
 	return result
 }
 
-// qobuzSameWordsUnordered checks if two strings have the same words regardless of order
-// Useful for Japanese names: "Sawano Hiroyuki" vs "Hiroyuki Sawano"
 func qobuzSameWordsUnordered(a, b string) bool {
 	wordsA := strings.Fields(a)
 	wordsB := strings.Fields(b)
 
-	// Must have same number of words
 	if len(wordsA) != len(wordsB) || len(wordsA) == 0 {
 		return false
 	}
 
-	// Sort and compare
 	sortedA := make([]string, len(wordsA))
 	sortedB := make([]string, len(wordsB))
 	copy(sortedA, wordsA)
 	copy(sortedB, wordsB)
 
-	// Simple bubble sort (usually just 2-3 words)
 	for i := 0; i < len(sortedA)-1; i++ {
 		for j := i + 1; j < len(sortedA); j++ {
 			if sortedA[i] > sortedA[j] {
@@ -160,22 +142,18 @@ func qobuzSameWordsUnordered(a, b string) bool {
 	return true
 }
 
-// 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)
 
@@ -183,14 +161,12 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 		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)
 
@@ -198,8 +174,6 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 		return true
 	}
 
-	// If scripts are TRULY different (Latin vs CJK/Arabic/Cyrillic), assume match (transliteration)
-	// Don't treat Latin Extended (Polish, French, etc.) as different script
 	expectedLatin := qobuzIsLatinScript(expectedTitle)
 	foundLatin := qobuzIsLatinScript(foundTitle)
 	if expectedLatin != foundLatin {
@@ -210,9 +184,7 @@ func qobuzTitlesMatch(expectedTitle, foundTitle string) bool {
 	return false
 }
 
-// qobuzExtractCoreTitle extracts the main title before any parentheses or brackets
 func qobuzExtractCoreTitle(title string) string {
-	// Find first occurrence of ( or [
 	parenIdx := strings.Index(title, "(")
 	bracketIdx := strings.Index(title, "[")
 	dashIdx := strings.Index(title, " - ")
@@ -231,19 +203,15 @@ func qobuzExtractCoreTitle(title string) string {
 	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, ")")
@@ -264,7 +232,6 @@ func qobuzCleanTitle(title string) string {
 		break
 	}
 
-	// Same for brackets
 	for {
 		startBracket := strings.LastIndex(cleaned, "[")
 		endBracket := strings.LastIndex(cleaned, "]")
@@ -285,7 +252,6 @@ func qobuzCleanTitle(title string) string {
 		break
 	}
 
-	// Remove trailing " - version" patterns
 	dashPatterns := []string{
 		" - remaster", " - remastered", " - single version", " - radio edit",
 		" - live", " - acoustic", " - demo", " - remix",
@@ -296,7 +262,6 @@ func qobuzCleanTitle(title string) string {
 		}
 	}
 
-	// Remove multiple spaces
 	for strings.Contains(cleaned, "  ") {
 		cleaned = strings.ReplaceAll(cleaned, "  ", " ")
 	}
@@ -304,49 +269,28 @@ func qobuzCleanTitle(title string) string {
 	return strings.TrimSpace(cleaned)
 }
 
-// qobuzIsLatinScript checks if a string is primarily Latin script
-// Returns true for ASCII and Latin Extended characters (European languages)
-// Returns false for CJK, Arabic, Cyrillic, etc.
 func qobuzIsLatinScript(s string) bool {
 	for _, r := range s {
-		// Skip common punctuation and numbers
 		if r < 128 {
 			continue
 		}
-		// Latin Extended-A: U+0100 to U+017F (Polish, Czech, etc.)
+		if (r >= 0x0100 && r <= 0x024F) ||
-		// Latin Extended-B: U+0180 to U+024F
+			(r >= 0x1E00 && r <= 0x1EFF) ||
-		// Latin Extended Additional: U+1E00 to U+1EFF
+			(r >= 0x00C0 && r <= 0x00FF) {
-		// Latin Extended-C/D/E: various ranges
-		if (r >= 0x0100 && r <= 0x024F) || // Latin Extended A & B
-			(r >= 0x1E00 && r <= 0x1EFF) || // Latin Extended Additional
-			(r >= 0x00C0 && r <= 0x00FF) { // Latin-1 Supplement (accented chars)
 			continue
 		}
-		// CJK ranges - definitely different script
+		if (r >= 0x4E00 && r <= 0x9FFF) ||
-		if (r >= 0x4E00 && r <= 0x9FFF) || // CJK Unified Ideographs
+			(r >= 0x3040 && r <= 0x309F) ||
-			(r >= 0x3040 && r <= 0x309F) || // Hiragana
+			(r >= 0x30A0 && r <= 0x30FF) ||
-			(r >= 0x30A0 && r <= 0x30FF) || // Katakana
+			(r >= 0xAC00 && r <= 0xD7AF) ||
-			(r >= 0xAC00 && r <= 0xD7AF) || // Hangul (Korean)
+			(r >= 0x0600 && r <= 0x06FF) ||
-			(r >= 0x0600 && r <= 0x06FF) || // Arabic
+			(r >= 0x0400 && r <= 0x04FF) {
-			(r >= 0x0400 && r <= 0x04FF) { // Cyrillic
 			return false
 		}
 	}
 	return true
 }
 
-// qobuzIsASCIIString checks if a string contains only ASCII characters
-// Kept for potential future use
-// func qobuzIsASCIIString(s string) bool {
-// 	for _, r := range s {
-// 		if r > 127 {
-// 			return false
-// 		}
-// 	}
-// 	return true
-// }
-
-// containsQueryQobuz checks if a query already exists in the list
 func containsQueryQobuz(queries []string, query string) bool {
 	for _, q := range queries {
 		if q == query {
@@ -356,25 +300,48 @@ func containsQueryQobuz(queries []string, query string) bool {
 	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
+			client: NewHTTPClientWithTimeout(DefaultTimeout),
 			appID:  "798273057",
 		}
 	})
 	return globalQobuzDownloader
 }
 
-// GetAvailableAPIs returns list of available Qobuz APIs
+func (q *QobuzDownloader) GetTrackByID(trackID int64) (*QobuzTrack, error) {
-// Uses same APIs as PC version for compatibility
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9nZXQ/dHJhY2tfaWQ9")
+	trackURL := fmt.Sprintf("%s%d&app_id=%s", string(apiBase), trackID, q.appID)
+
+	req, err := http.NewRequest("GET", trackURL, 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("get track failed: HTTP %d", resp.StatusCode)
+	}
+
+	var track QobuzTrack
+	if err := json.NewDecoder(resp.Body).Decode(&track); err != nil {
+		return nil, err
+	}
+
+	return &track, nil
+}
+
 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)
+		"ZGFiLnllZXQuc3UvYXBpL3N0cmVhbT90cmFja0lkPQ==",
-		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=", // dabmusic.xyz/api/stream?trackId= (FALLBACK - same as PC)
+		"ZGFibXVzaWMueHl6L2FwaS9zdHJlYW0/dHJhY2tJZD0=",
+		"cW9idXouc3F1aWQud3RmL2FwaS9kb3dubG9hZC1tdXNpYz90cmFja19pZD0=",
 	}
 
 	var apis []string
@@ -389,7 +356,86 @@ func (q *QobuzDownloader) GetAvailableAPIs() []string {
 	return apis
 }
 
-// SearchTrackByISRC searches for a track by ISRC
+func mapJumoQuality(quality string) int {
+	switch quality {
+	case "6":
+		return 6
+	case "7":
+		return 7
+	case "27":
+		return 27
+	default:
+		return 6
+	}
+}
+
+func decodeXOR(data []byte) string {
+	text := string(data)
+	runes := []rune(text)
+	result := make([]rune, len(runes))
+	for i, char := range runes {
+		key := rune((i * 17) % 128)
+		result[i] = char ^ 253 ^ key
+	}
+	return string(result)
+}
+
+func (q *QobuzDownloader) downloadFromJumo(trackID int64, quality string) (string, error) {
+	formatID := mapJumoQuality(quality)
+	region := "US"
+	jumoURL := fmt.Sprintf("https://jumo-dl.pages.dev/file?track_id=%d&format_id=%d&region=%s", trackID, formatID, region)
+
+	GoLog("[Qobuz] Trying Jumo API fallback...\n")
+
+	client := NewHTTPClientWithTimeout(30 * time.Second)
+	req, err := http.NewRequest("GET", jumoURL, nil)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("Jumo API returned HTTP %d", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	var result map[string]any
+	if err := json.Unmarshal(body, &result); err != nil {
+		decoded := decodeXOR(body)
+		if err := json.Unmarshal([]byte(decoded), &result); err != nil {
+			return "", fmt.Errorf("failed to parse Jumo response (plain or XOR): %w", err)
+		}
+	}
+
+	if urlVal, ok := result["url"].(string); ok && urlVal != "" {
+		GoLog("[Qobuz] Jumo API returned URL successfully\n")
+		return urlVal, nil
+	}
+
+	if data, ok := result["data"].(map[string]any); ok {
+		if urlVal, ok := data["url"].(string); ok && urlVal != "" {
+			GoLog("[Qobuz] Jumo API returned URL successfully (from data)\n")
+			return urlVal, nil
+		}
+	}
+
+	if linkVal, ok := result["link"].(string); ok && linkVal != "" {
+		GoLog("[Qobuz] Jumo API returned URL successfully (from link)\n")
+		return linkVal, nil
+	}
+
+	return "", fmt.Errorf("URL not found in Jumo response")
+}
+
 func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
 	searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(isrc), q.appID)
@@ -418,7 +464,6 @@ func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 		return nil, err
 	}
 
-	// Find exact ISRC match
 	for i := range result.Tracks.Items {
 		if result.Tracks.Items[i].ISRC == isrc {
 			return &result.Tracks.Items[i], nil
@@ -432,8 +477,6 @@ 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)
 
@@ -466,7 +509,6 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 
 	GoLog("[Qobuz] ISRC search returned %d results\n", len(result.Tracks.Items))
 
-	// Find ISRC matches
 	var isrcMatches []*QobuzTrack
 	for i := range result.Tracks.Items {
 		if result.Tracks.Items[i].ISRC == isrc {
@@ -477,7 +519,6 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 	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 {
@@ -485,7 +526,6 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 				if durationDiff < 0 {
 					durationDiff = -durationDiff
 				}
-				// Allow 10 seconds tolerance
 				if durationDiff <= 10 {
 					durationVerifiedMatches = append(durationVerifiedMatches, track)
 				}
@@ -497,14 +537,12 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 				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
 	}
@@ -516,46 +554,34 @@ func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDur
 	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 (same as Tidal/PC version)
 	queries := []string{}
 
-	// Strategy 1: Artist + Track name
 	if artistName != "" && trackName != "" {
 		queries = append(queries, artistName+" "+trackName)
 	}
 
-	// Strategy 2: Track name only
 	if trackName != "" {
 		queries = append(queries, trackName)
 	}
 
-	// Strategy 3: Romaji versions if Japanese detected
 	if ContainsJapanese(trackName) || ContainsJapanese(artistName) {
-		// Convert to romaji (hiragana/katakana only, kanji stays)
 		romajiTrack := JapaneseToRomaji(trackName)
 		romajiArtist := JapaneseToRomaji(artistName)
 
-		// Clean and remove ALL non-ASCII characters (including kanji)
 		cleanRomajiTrack := CleanToASCII(romajiTrack)
 		cleanRomajiArtist := CleanToASCII(romajiArtist)
 
-		// Artist + Track romaji (cleaned to ASCII only)
 		if cleanRomajiArtist != "" && cleanRomajiTrack != "" {
 			romajiQuery := cleanRomajiArtist + " " + cleanRomajiTrack
 			if !containsQueryQobuz(queries, romajiQuery) {
@@ -564,7 +590,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 			}
 		}
 
-		// Track romaji only (cleaned)
 		if cleanRomajiTrack != "" && cleanRomajiTrack != trackName {
 			if !containsQueryQobuz(queries, cleanRomajiTrack) {
 				queries = append(queries, cleanRomajiTrack)
@@ -572,7 +597,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		}
 	}
 
-	// Strategy 4: Artist only as last resort
 	if artistName != "" {
 		artistOnly := CleanToASCII(JapaneseToRomaji(artistName))
 		if artistOnly != "" && !containsQueryQobuz(queries, artistOnly) {
@@ -631,7 +655,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		return nil, fmt.Errorf("no tracks found for: %s - %s", artistName, trackName)
 	}
 
-	// Filter by title match first (NEW - like Tidal)
 	var titleMatches []*QobuzTrack
 	for i := range allTracks {
 		track := &allTracks[i]
@@ -642,7 +665,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 
 	GoLog("[Qobuz] Title matches: %d out of %d results\n", len(titleMatches), len(allTracks))
 
-	// If no title matches, log warning but continue with all tracks
 	tracksToCheck := titleMatches
 	if len(titleMatches) == 0 {
 		GoLog("[Qobuz] WARNING: No title matches for '%s', checking all %d results\n", trackName, len(allTracks))
@@ -651,7 +673,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		}
 	}
 
-	// If duration verification is requested
 	if expectedDurationSec > 0 {
 		var durationMatches []*QobuzTrack
 		for _, track := range tracksToCheck {
@@ -665,34 +686,31 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 		}
 
 		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",
+					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",
+			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",
+			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",
+		GoLog("[Qobuz] Match found: '%s' by '%s' (title verified)\n",
 			tracksToCheck[0].Title, tracksToCheck[0].Performer.Name)
 		return tracksToCheck[0], nil
 	}
@@ -700,7 +718,6 @@ func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistNam
 	return nil, fmt.Errorf("no matching track found for: %s - %s", artistName, trackName)
 }
 
-// qobuzAPIResult holds the result from a parallel API request
 type qobuzAPIResult struct {
 	apiURL      string
 	downloadURL string
@@ -708,8 +725,6 @@ type qobuzAPIResult struct {
 	duration    time.Duration
 }
 
-// getQobuzDownloadURLParallel requests download URL from all APIs in parallel
-// "Siapa cepat dia dapat" - first successful response wins
 func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (string, string, error) {
 	if len(apis) == 0 {
 		return "", "", fmt.Errorf("no APIs available")
@@ -720,14 +735,11 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 	resultChan := make(chan qobuzAPIResult, len(apis))
 	startTime := time.Now()
 
-	// Start all requests in parallel
 	for _, apiURL := range apis {
 		go func(api string) {
 			reqStart := time.Now()
 
-			client := &http.Client{
+			client := NewHTTPClientWithTimeout(15 * time.Second)
-				Timeout: 15 * time.Second,
-			}
 
 			reqURL := fmt.Sprintf("%s%d&quality=%s", api, trackID, quality)
 
@@ -755,13 +767,11 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 				return
 			}
 
-			// Check if response is HTML (error page)
 			if len(body) > 0 && body[0] == '<' {
 				resultChan <- qobuzAPIResult{apiURL: api, err: fmt.Errorf("received HTML instead of JSON"), duration: time.Since(reqStart)}
 				return
 			}
 
-			// Check for error in JSON response
 			var errorResp struct {
 				Error string `json:"error"`
 			}
@@ -787,15 +797,13 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 		}(apiURL)
 	}
 
-	// Collect results - return first success
 	var errors []string
 
 	for i := 0; i < len(apis); i++ {
 		result := <-resultChan
 		if result.err == nil {
-			GoLog("[Qobuz] [Parallel] ✓ Got response from %s in %v\n", result.apiURL, result.duration)
+			GoLog("[Qobuz] [Parallel] Got response from %s in %v\n", result.apiURL, result.duration)
 
-			// Drain remaining results to avoid goroutine leaks
 			go func(remaining int) {
 				for j := 0; j < remaining; j++ {
 					<-resultChan
@@ -816,38 +824,66 @@ func getQobuzDownloadURLParallel(apis []string, trackID int64, quality string) (
 	return "", "", fmt.Errorf("all %d Qobuz APIs failed. Errors: %v", len(apis), errors)
 }
 
-// GetDownloadURL gets download URL for a track - tries ALL APIs in parallel
-// "Siapa cepat dia dapat" - first successful response wins
 func (q *QobuzDownloader) GetDownloadURL(trackID int64, quality string) (string, error) {
 	apis := q.GetAvailableAPIs()
 	if len(apis) == 0 {
 		return "", fmt.Errorf("no Qobuz API available")
 	}
 
-	// Use parallel approach - request from all APIs simultaneously
 	_, downloadURL, err := getQobuzDownloadURLParallel(apis, trackID, quality)
-	if err != nil {
+	if err == nil {
-		return "", err
+		return downloadURL, nil
 	}
 
-	return downloadURL, nil
+	GoLog("[Qobuz] Standard APIs failed, trying Jumo fallback...\n")
+	jumoURL, jumoErr := q.downloadFromJumo(trackID, quality)
+	if jumoErr == nil {
+		return jumoURL, nil
+	}
+
+	if quality == "27" {
+		GoLog("[Qobuz] Hi-res (27) failed, trying 24-bit (7)...\n")
+		jumoURL, jumoErr = q.downloadFromJumo(trackID, "7")
+		if jumoErr == nil {
+			return jumoURL, nil
+		}
+	}
+
+	if quality == "27" || quality == "7" {
+		GoLog("[Qobuz] 24-bit failed, trying 16-bit (6)...\n")
+		jumoURL, jumoErr = q.downloadFromJumo(trackID, "6")
+		if jumoErr == nil {
+			return jumoURL, nil
+		}
+	}
+
+	return "", fmt.Errorf("all Qobuz APIs and Jumo fallback failed: %w", err)
 }
 
-// DownloadFile downloads a file from URL with User-Agent and progress tracking
 func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) error {
-	// Initialize item progress (required for all downloads)
+	ctx := context.Background()
+
 	if itemID != "" {
 		StartItemProgress(itemID)
 		defer CompleteItemProgress(itemID)
+		ctx = initDownloadCancel(itemID)
+		defer clearDownloadCancel(itemID)
 	}
 
-	req, err := http.NewRequest("GET", downloadURL, nil)
+	if isDownloadCancelled(itemID) {
+		return ErrDownloadCancelled
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", downloadURL, nil)
 	if err != nil {
 		return fmt.Errorf("failed to create request: %w", err)
 	}
 
 	resp, err := DoRequestWithUserAgent(q.client, req)
 	if err != nil {
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
 		return err
 	}
 	defer resp.Body.Close()
@@ -857,7 +893,6 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 	}
 
 	expectedSize := resp.ContentLength
-	// Set total bytes if available
 	if expectedSize > 0 && itemID != "" {
 		SetItemBytesTotal(itemID, expectedSize)
 	}
@@ -867,26 +902,24 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		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)
+		if isDownloadCancelled(itemID) {
+			return ErrDownloadCancelled
+		}
 		return fmt.Errorf("download interrupted: %w", err)
 	}
 	if flushErr != nil {
@@ -898,7 +931,6 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 		return fmt.Errorf("failed to close file: %w", closeErr)
 	}
 
-	// Verify file size if Content-Length was provided
 	if expectedSize > 0 && written != expectedSize {
 		os.Remove(outputPath)
 		return fmt.Errorf("incomplete download: expected %d bytes, got %d bytes", expectedSize, written)
@@ -907,7 +939,6 @@ func (q *QobuzDownloader) DownloadFile(downloadURL, outputPath, itemID string) e
 	return nil
 }
 
-// QobuzDownloadResult contains download result with quality info
 type QobuzDownloadResult struct {
 	FilePath    string
 	BitDepth    int
@@ -921,26 +952,35 @@ type QobuzDownloadResult struct {
 	ISRC        string
 }
 
-// downloadFromQobuz downloads a track using the request parameters
 func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 	downloader := NewQobuzDownloader()
 
-	// Check for existing file first
 	if existingFile, exists := checkISRCExistsInternal(req.OutputDir, req.ISRC); exists {
 		return QobuzDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
-	// Convert expected duration from ms to seconds
 	expectedDurationSec := req.DurationMS / 1000
 
 	var track *QobuzTrack
 	var err error
 
-	// OPTIMIZATION: Check cache first for track ID
+	if req.QobuzID != "" {
-	if req.ISRC != "" {
+		GoLog("[Qobuz] Using Qobuz ID from Odesli enrichment: %s\n", req.QobuzID)
+		var trackID int64
+		if _, parseErr := fmt.Sscanf(req.QobuzID, "%d", &trackID); parseErr == nil && trackID > 0 {
+			track, err = downloader.GetTrackByID(trackID)
+			if err != nil {
+				GoLog("[Qobuz] Failed to get track by Odesli ID %d: %v\n", trackID, err)
+				track = nil
+			} else if track != nil {
+				GoLog("[Qobuz] Successfully found track via Odesli ID: '%s' by '%s'\n", track.Title, track.Performer.Name)
+			}
+		}
+	}
+
+	if track == nil && req.ISRC != "" {
 		if cached := GetTrackIDCache().Get(req.ISRC); cached != nil && cached.QobuzTrackID > 0 {
 			GoLog("[Qobuz] Cache hit! Using cached track ID: %d\n", cached.QobuzTrackID)
-			// For Qobuz we need to search again to get full track info, but we can use the ID
 			track, err = downloader.SearchTrackByISRC(req.ISRC)
 			if err != nil {
 				GoLog("[Qobuz] Cache hit but search failed: %v\n", err)
@@ -949,11 +989,9 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		}
 	}
 
-	// Strategy 1: Search by ISRC with duration verification
 	if track == nil && req.ISRC != "" {
 		GoLog("[Qobuz] Trying ISRC search: %s\n", req.ISRC)
 		track, err = downloader.SearchTrackByISRCWithDuration(req.ISRC, expectedDurationSec)
-		// Verify artist AND title
 		if track != nil {
 			if !qobuzArtistsMatch(req.ArtistName, track.Performer.Name) {
 				GoLog("[Qobuz] Artist mismatch from ISRC search: expected '%s', got '%s'. Rejecting.\n",
@@ -967,10 +1005,8 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		}
 	}
 
-	// Strategy 2: Search by metadata with duration verification (includes title verification)
 	if track == nil {
 		track, err = downloader.SearchTrackByMetadataWithDuration(req.TrackName, req.ArtistName, expectedDurationSec)
-		// Verify artist (title already verified in SearchTrackByMetadataWithDuration)
 		if track != nil && !qobuzArtistsMatch(req.ArtistName, track.Performer.Name) {
 			GoLog("[Qobuz] Artist mismatch from metadata search: expected '%s', got '%s'. Rejecting.\n",
 				req.ArtistName, track.Performer.Name)
@@ -986,13 +1022,11 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{}, fmt.Errorf("qobuz search failed: %s", errMsg)
 	}
 
-	// Log match found and cache the track ID
 	GoLog("[Qobuz] Match found: '%s' by '%s' (duration: %ds)\n", track.Title, track.Performer.Name, track.Duration)
 	if req.ISRC != "" {
 		GetTrackIDCache().SetQobuz(req.ISRC, track.ID)
 	}
 
-	// Build filename
 	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
 		"title":  req.TrackName,
 		"artist": req.ArtistName,
@@ -1004,37 +1038,30 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 	filename = sanitizeFilename(filename) + ".flac"
 	outputPath := filepath.Join(req.OutputDir, filename)
 
-	// Check if file already exists
 	if fileInfo, statErr := os.Stat(outputPath); statErr == nil && fileInfo.Size() > 0 {
 		return QobuzDownloadResult{FilePath: "EXISTS:" + outputPath}, nil
 	}
 
-	// Map quality from Tidal format to Qobuz format
+	qobuzQuality := "27"
-	// Tidal: LOSSLESS (16-bit), HI_RES (24-bit), HI_RES_LOSSLESS (24-bit hi-res)
-	// Qobuz: 5 (MP3 320), 6 (16-bit), 7 (24-bit 96kHz), 27 (24-bit 192kHz)
-	qobuzQuality := "27" // Default to highest quality
 	switch req.Quality {
 	case "LOSSLESS":
-		qobuzQuality = "6" // 16-bit FLAC
+		qobuzQuality = "6"
 	case "HI_RES":
-		qobuzQuality = "7" // 24-bit 96kHz
+		qobuzQuality = "7"
 	case "HI_RES_LOSSLESS":
-		qobuzQuality = "27" // 24-bit 192kHz
+		qobuzQuality = "27"
 	}
 	GoLog("[Qobuz] Using quality: %s (mapped from %s)\n", qobuzQuality, req.Quality)
 
-	// Get actual quality from track metadata
 	actualBitDepth := track.MaximumBitDepth
-	actualSampleRate := int(track.MaximumSamplingRate * 1000) // Convert kHz to Hz
+	actualSampleRate := int(track.MaximumSamplingRate * 1000)
 	GoLog("[Qobuz] Actual quality: %d-bit/%.1fkHz\n", actualBitDepth, track.MaximumSamplingRate)
 
-	// Get download URL using parallel API requests
 	downloadURL, err := downloader.GetDownloadURL(track.ID, qobuzQuality)
 	if err != nil {
 		return QobuzDownloadResult{}, fmt.Errorf("failed to get download URL: %w", err)
 	}
 
-	// START PARALLEL: Fetch cover and lyrics while downloading audio
 	var parallelResult *ParallelDownloadResult
 	parallelDone := make(chan struct{})
 	go func() {
@@ -1046,45 +1073,49 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 			req.TrackName,
 			req.ArtistName,
 			req.EmbedLyrics,
+			int64(req.DurationMS),
 		)
 	}()
 
-	// Download audio file with item ID for progress tracking
 	if err := downloader.DownloadFile(downloadURL, outputPath, req.ItemID); err != nil {
+		if errors.Is(err, ErrDownloadCancelled) {
+			return QobuzDownloadResult{}, ErrDownloadCancelled
+		}
 		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
 	}
 
+	actualTrackNumber := req.TrackNumber
+	if actualTrackNumber == 0 {
+		actualTrackNumber = track.TrackNumber
+	}
+
 	metadata := Metadata{
 		Title:       track.Title,
 		Artist:      track.Performer.Name,
 		Album:       albumName,
-		AlbumArtist: req.AlbumArtist, // Qobuz track struct might not have this handy, keep req or check album struct
+		AlbumArtist: req.AlbumArtist,
 		Date:        track.Album.ReleaseDate,
-		TrackNumber: track.TrackNumber,
+		TrackNumber: actualTrackNumber,
 		TotalTracks: req.TotalTracks,
-		DiscNumber:  req.DiscNumber, // QobuzTrack struct usually doesn't have disc info in simple search result
+		DiscNumber:  req.DiscNumber,
 		ISRC:        track.ISRC,
+		Genre:       req.Genre,
+		Label:       req.Label,
+		Copyright:   req.Copyright,
 	}
 
-	// Use cover data from parallel fetch
 	var coverData []byte
 	if parallelResult != nil && parallelResult.CoverData != nil {
 		coverData = parallelResult.CoverData
@@ -1095,19 +1126,33 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		fmt.Printf("Warning: failed to embed metadata: %v\n", err)
 	}
 
-	// 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))
+		lyricsMode := req.LyricsMode
-		if embedErr := EmbedLyrics(outputPath, parallelResult.LyricsLRC); embedErr != nil {
+		if lyricsMode == "" {
-			GoLog("[Qobuz] Warning: failed to embed lyrics: %v\n", embedErr)
+			lyricsMode = "embed"
-		} else {
+		}
-			fmt.Println("[Qobuz] Lyrics embedded successfully")
+
+		if lyricsMode == "external" || lyricsMode == "both" {
+			GoLog("[Qobuz] Saving external LRC file...\n")
+			if lrcPath, lrcErr := SaveLRCFile(outputPath, parallelResult.LyricsLRC); lrcErr != nil {
+				GoLog("[Qobuz] Warning: failed to save LRC file: %v\n", lrcErr)
+			} else {
+				GoLog("[Qobuz] LRC file saved: %s\n", lrcPath)
+			}
+		}
+
+		if lyricsMode == "embed" || lyricsMode == "both" {
+			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.Println("[Qobuz] Lyrics embedded successfully")
+			}
 		}
 	} else if req.EmbedLyrics {
 		fmt.Println("[Qobuz] No lyrics available from parallel fetch")
 	}
 
-	// Add to ISRC index for fast duplicate checking
 	AddToISRCIndex(req.OutputDir, req.ISRC, outputPath)
 
 	return QobuzDownloadResult{
@@ -1118,8 +1163,8 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		Artist:      track.Performer.Name,
 		Album:       track.Album.Title,
 		ReleaseDate: track.Album.ReleaseDate,
-		TrackNumber: track.TrackNumber,
+		TrackNumber: actualTrackNumber,
-		DiscNumber:  req.DiscNumber, // Qobuz track struct limitations
+		DiscNumber:  req.DiscNumber,
 		ISRC:        track.ISRC,
 	}, nil
 }

go_backend/ratelimit.go

@@ -5,7 +5,6 @@ import (
 	"time"
 )
 
-// RateLimiter implements a sliding window rate limiter
 type RateLimiter struct {
 	mu          sync.Mutex
 	maxRequests int
@@ -13,7 +12,6 @@ type RateLimiter struct {
 	timestamps  []time.Time
 }
 
-// NewRateLimiter creates a new rate limiter with specified max requests per window
 func NewRateLimiter(maxRequests int, window time.Duration) *RateLimiter {
 	return &RateLimiter{
 		maxRequests: maxRequests,
@@ -22,39 +20,31 @@ func NewRateLimiter(maxRequests int, window time.Duration) *RateLimiter {
 	}
 }
 
-// WaitForSlot blocks until a request is allowed under the rate limit
-// Returns immediately if under the limit, otherwise waits until a slot is available
 func (r *RateLimiter) WaitForSlot() {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
 	now := time.Now()
 
-	// Remove timestamps outside the window
 	r.cleanOldTimestamps(now)
 
-	// If under limit, record and return immediately
 	if len(r.timestamps) < r.maxRequests {
 		r.timestamps = append(r.timestamps, now)
 		return
 	}
 
-	// Calculate wait time until oldest timestamp expires
 	oldestTimestamp := r.timestamps[0]
 	waitUntil := oldestTimestamp.Add(r.window)
 	waitDuration := waitUntil.Sub(now)
 
 	if waitDuration > 0 {
-		// Release lock while waiting
 		r.mu.Unlock()
 		time.Sleep(waitDuration)
 		r.mu.Lock()
 
-		// Clean again after waiting
 		r.cleanOldTimestamps(time.Now())
 	}
 
-	// Record this request
 	r.timestamps = append(r.timestamps, time.Now())
 }
 
@@ -76,8 +66,6 @@ func (r *RateLimiter) cleanOldTimestamps(now time.Time) {
 	}
 }
 
-// TryAcquire attempts to acquire a slot without blocking
-// Returns true if successful, false if rate limit would be exceeded
 func (r *RateLimiter) TryAcquire() bool {
 	r.mu.Lock()
 	defer r.mu.Unlock()
@@ -93,7 +81,6 @@ func (r *RateLimiter) TryAcquire() bool {
 	return false
 }
 
-// Available returns the number of requests available in the current window
 func (r *RateLimiter) Available() int {
 	r.mu.Lock()
 	defer r.mu.Unlock()
@@ -105,7 +92,6 @@ func (r *RateLimiter) Available() int {
 // Global SongLink rate limiter - 9 requests per minute (to be safe, limit is 10)
 var songLinkRateLimiter = NewRateLimiter(9, time.Minute)
 
-// GetSongLinkRateLimiter returns the global SongLink rate limiter
 func GetSongLinkRateLimiter() *RateLimiter {
 	return songLinkRateLimiter
 }

go_backend/romaji.go

@@ -5,7 +5,6 @@ import (
 	"unicode"
 )
 
-// Hiragana to Romaji mapping
 var hiraganaToRomaji = map[rune]string{
 	'あ': "a", 'い': "i", 'う': "u", 'え': "e", 'お': "o",
 	'か': "ka", 'き': "ki", 'く': "ku", 'け': "ke", 'こ': "ko",
@@ -30,7 +29,6 @@ var hiraganaToRomaji = map[rune]string{
 	'ぁ': "a", 'ぃ': "i", 'ぅ': "u", 'ぇ': "e", 'ぉ': "o",
 }
 
-// Katakana to Romaji mapping
 var katakanaToRomaji = map[rune]string{
 	'ア': "a", 'イ': "i", 'ウ': "u", 'エ': "e", 'オ': "o",
 	'カ': "ka", 'キ': "ki", 'ク': "ku", 'ケ': "ke", 'コ': "ko",
@@ -58,7 +56,6 @@ var katakanaToRomaji = map[rune]string{
 	'ヴ': "vu",
 }
 
-// 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",
@@ -91,7 +88,6 @@ var combinationKatakana = map[string]string{
 	"ウィ": "wi", "ウェ": "we", "ウォ": "wo",
 }
 
-// ContainsJapanese checks if a string contains Japanese characters
 func ContainsJapanese(s string) bool {
 	for _, r := range s {
 		if isHiragana(r) || isKatakana(r) || isKanji(r) {
@@ -114,8 +110,6 @@ func isKanji(r rune) bool {
 		(r >= 0x3400 && r <= 0x4DBF) // CJK Unified Ideographs Extension A
 }
 
-// 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
@@ -175,8 +169,6 @@ func JapaneseToRomaji(text string) string {
 	return result.String()
 }
 
-// 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)
@@ -189,7 +181,6 @@ func BuildSearchQuery(trackName, artistName string) string {
 	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 {
@@ -202,8 +193,6 @@ func cleanSearchQuery(s string) string {
 	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 {

go_backend/songlink.go

@@ -11,12 +11,10 @@ import (
 	"time"
 )
 
-// SongLinkClient handles song.link API interactions
 type SongLinkClient struct {
 	client *http.Client
 }
 
-// TrackAvailability represents track availability on different platforms
 type TrackAvailability struct {
 	SpotifyID string `json:"spotify_id"`
 	Tidal     bool   `json:"tidal"`
@@ -31,32 +29,22 @@ type TrackAvailability struct {
 }
 
 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 {
 	songLinkClientOnce.Do(func() {
 		globalSongLinkClient = &SongLinkClient{
-			client: NewHTTPClientWithTimeout(SongLinkTimeout), // 30s timeout
+			client: NewHTTPClientWithTimeout(SongLinkTimeout),
 		}
 	})
 	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()
 
-	// Build API URL
 	spotifyBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9vcGVuLnNwb3RpZnkuY29tL3RyYWNrLw==")
 	spotifyURL := fmt.Sprintf("%s%s", string(spotifyBase), spotifyTrackID)
 
@@ -68,7 +56,6 @@ func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc stri
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}
 
-	// Use retry logic with User-Agent
 	retryConfig := DefaultRetryConfig()
 	resp, err := DoRequestWithRetry(s.client, req, retryConfig)
 	if err != nil {
@@ -76,7 +63,6 @@ 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)")
 	}
@@ -109,35 +95,25 @@ func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc stri
 		SpotifyID: spotifyTrackID,
 	}
 
-	// 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
-		// 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)
-	}
-
 	return availability, nil
 }
 
-// GetStreamingURLs gets streaming URLs for a Spotify track
 func (s *SongLinkClient) GetStreamingURLs(spotifyTrackID string) (map[string]string, error) {
 	availability, err := s.CheckTrackAvailability(spotifyTrackID, "")
 	if err != nil {
@@ -191,12 +167,9 @@ func checkQobuzAvailability(isrc string) bool {
 
 // 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]
 		}
@@ -205,17 +178,16 @@ func extractDeezerIDFromURL(deezerURL string) string {
 	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
 }
 
@@ -227,12 +199,9 @@ type AlbumAvailability struct {
 	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)
 
@@ -274,7 +243,6 @@ func (s *SongLinkClient) CheckAlbumAvailability(spotifyAlbumID string) (*AlbumAv
 		SpotifyID: spotifyAlbumID,
 	}
 
-	// Check Deezer
 	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
 		availability.Deezer = true
 		availability.DeezerURL = deezerLink.URL
@@ -290,32 +258,40 @@ func (s *SongLinkClient) GetDeezerAlbumIDFromSpotify(spotifyAlbumID string) (str
 	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
+	availability, err := s.checkAvailabilityFromDeezerSongLink(deezerTrackID)
+	if err != nil {
+		LogWarn("SongLink", "SongLink failed for Deezer, trying IDHS fallback: %v", err)
+		idhsClient := NewIDHSClient()
+		availability, err = idhsClient.GetAvailabilityFromDeezer(deezerTrackID)
+		if err != nil {
+			return nil, fmt.Errorf("both SongLink and IDHS failed: %w", err)
+		}
+		LogInfo("SongLink", "IDHS fallback successful for Deezer %s", deezerTrackID)
+	}
+
+	return availability, nil
+}
+
+// checkAvailabilityFromDeezerSongLink is the original SongLink implementation for Deezer
+func (s *SongLinkClient) checkAvailabilityFromDeezerSongLink(deezerTrackID string) (*TrackAvailability, error) {
 	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))
 
@@ -331,7 +307,6 @@ func (s *SongLinkClient) CheckAvailabilityFromDeezer(deezerTrackID string) (*Tra
 	}
 	defer resp.Body.Close()
 
-	// Handle specific error codes
 	if resp.StatusCode == 400 {
 		return nil, fmt.Errorf("track not found on SongLink (invalid Deezer ID)")
 	}
@@ -371,25 +346,20 @@ func (s *SongLinkClient) CheckAvailabilityFromDeezer(deezerTrackID string) (*Tra
 		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
 	}
@@ -397,7 +367,6 @@ func (s *SongLinkClient) CheckAvailabilityFromDeezer(deezerTrackID string) (*Tra
 	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
@@ -405,12 +374,9 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 	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),
@@ -428,7 +394,6 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 	}
 	defer resp.Body.Close()
 
-	// Handle specific error codes
 	if resp.StatusCode == 400 {
 		return nil, fmt.Errorf("track not found on SongLink (invalid %s ID)", platform)
 	}
@@ -459,24 +424,20 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 
 	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
@@ -488,10 +449,8 @@ func (s *SongLinkClient) CheckAvailabilityByPlatform(platform, entityType, entit
 
 // 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]
@@ -501,17 +460,16 @@ func extractSpotifyIDFromURL(spotifyURL string) string {
 	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
 }
 
@@ -521,24 +479,23 @@ func (s *SongLinkClient) GetTidalURLFromDeezer(deezerTrackID string) (string, er
 	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

@@ -24,7 +24,6 @@ const (
 	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
@@ -32,7 +31,6 @@ const (
 
 var errInvalidSpotifyURL = errors.New("invalid or unsupported Spotify URL")
 
-// cacheEntry holds cached data with expiration
 type cacheEntry struct {
 	data      interface{}
 	expiresAt time.Time
@@ -42,26 +40,23 @@ func (e *cacheEntry) isExpired() bool {
 	return time.Now().After(e.expiresAt)
 }
 
-// SpotifyMetadataClient handles Spotify API interactions
 type SpotifyMetadataClient struct {
 	httpClient     *http.Client
 	clientID       string
 	clientSecret   string
 	cachedToken    string
 	tokenExpiresAt time.Time
-	tokenMu        sync.Mutex // Protects token cache for concurrent access
+	tokenMu        sync.Mutex
 	rng            *rand.Rand
 	rngMu          sync.Mutex
 	userAgent      string
 
-	// Caches to reduce API calls
+	artistCache map[string]*cacheEntry
-	artistCache map[string]*cacheEntry // key: artistID
+	searchCache map[string]*cacheEntry
-	searchCache map[string]*cacheEntry // key: query+type
+	albumCache  map[string]*cacheEntry
-	albumCache  map[string]*cacheEntry // key: albumID
 	cacheMu     sync.RWMutex
 }
 
-// Custom credentials storage (set from Flutter)
 var (
 	customClientID     string
 	customClientSecret string
@@ -71,7 +66,6 @@ var (
 // ErrNoSpotifyCredentials is returned when Spotify credentials are not configured
 var ErrNoSpotifyCredentials = errors.New("Spotify credentials not configured. Please set your own Client ID and Secret in Settings, or use Deezer as metadata source (free, no credentials required)")
 
-// SetSpotifyCredentials sets custom Spotify API credentials
 func SetSpotifyCredentials(clientID, clientSecret string) {
 	credentialsMu.Lock()
 	defer credentialsMu.Unlock()
@@ -79,17 +73,14 @@ func SetSpotifyCredentials(clientID, clientSecret string) {
 	customClientSecret = clientSecret
 }
 
-// HasSpotifyCredentials checks if Spotify credentials are configured
 func HasSpotifyCredentials() bool {
 	credentialsMu.RLock()
 	defer credentialsMu.RUnlock()
 
-	// Check custom credentials first
 	if customClientID != "" && customClientSecret != "" {
 		return true
 	}
 
-	// Check environment variables
 	if os.Getenv("SPOTIFY_CLIENT_ID") != "" && os.Getenv("SPOTIFY_CLIENT_SECRET") != "" {
 		return true
 	}
@@ -97,17 +88,14 @@ func HasSpotifyCredentials() bool {
 	return false
 }
 
-// getCredentials returns the current credentials or error if not configured
 func getCredentials() (string, string, error) {
 	credentialsMu.RLock()
 	defer credentialsMu.RUnlock()
 
-	// Check custom credentials first
 	if customClientID != "" && customClientSecret != "" {
 		return customClientID, customClientSecret, nil
 	}
 
-	// Check environment variables
 	clientID := os.Getenv("SPOTIFY_CLIENT_ID")
 	clientSecret := os.Getenv("SPOTIFY_CLIENT_SECRET")
 
@@ -115,14 +103,10 @@ func getCredentials() (string, string, error) {
 		return clientID, clientSecret, nil
 	}
 
-	// No credentials available
 	return "", "", ErrNoSpotifyCredentials
 }
 
-// NewSpotifyMetadataClient creates a new Spotify client
-// Returns error if credentials are not configured
 func NewSpotifyMetadataClient() (*SpotifyMetadataClient, error) {
-	// Get credentials - will error if not configured
 	clientID, clientSecret, err := getCredentials()
 	if err != nil {
 		return nil, err
@@ -131,7 +115,7 @@ func NewSpotifyMetadataClient() (*SpotifyMetadataClient, error) {
 	src := rand.NewSource(time.Now().UnixNano())
 
 	c := &SpotifyMetadataClient{
-		httpClient:   NewHTTPClientWithTimeout(15 * time.Second), // Use shared transport for connection pooling
+		httpClient:   NewHTTPClientWithTimeout(15 * time.Second),
 		clientID:     clientID,
 		clientSecret: clientSecret,
 		rng:          rand.New(src),
@@ -143,7 +127,6 @@ func NewSpotifyMetadataClient() (*SpotifyMetadataClient, error) {
 	return c, nil
 }
 
-// TrackMetadata represents track information
 type TrackMetadata struct {
 	SpotifyID   string `json:"spotify_id,omitempty"`
 	Artists     string `json:"artists"`
@@ -161,7 +144,6 @@ type TrackMetadata struct {
 	AlbumType   string `json:"album_type,omitempty"` // album, single, ep, compilation
 }
 
-// AlbumTrackMetadata holds per-track info for album/playlist
 type AlbumTrackMetadata struct {
 	SpotifyID   string `json:"spotify_id,omitempty"`
 	Artists     string `json:"artists"`
@@ -178,25 +160,26 @@ type AlbumTrackMetadata struct {
 	ISRC        string `json:"isrc"`
 	AlbumID     string `json:"album_id,omitempty"`
 	AlbumURL    string `json:"album_url,omitempty"`
-	AlbumType   string `json:"album_type,omitempty"` // album, single, ep, compilation
+	AlbumType   string `json:"album_type,omitempty"`
 }
 
-// AlbumInfoMetadata holds album information
 type AlbumInfoMetadata struct {
 	TotalTracks int    `json:"total_tracks"`
 	Name        string `json:"name"`
 	ReleaseDate string `json:"release_date"`
 	Artists     string `json:"artists"`
+	ArtistId    string `json:"artist_id,omitempty"`
 	Images      string `json:"images"`
+	Genre       string `json:"genre,omitempty"`
+	Label       string `json:"label,omitempty"`
+	Copyright   string `json:"copyright,omitempty"`
 }
 
-// AlbumResponsePayload is the response for album requests
 type AlbumResponsePayload struct {
 	AlbumInfo AlbumInfoMetadata    `json:"album_info"`
 	TrackList []AlbumTrackMetadata `json:"track_list"`
 }
 
-// PlaylistInfoMetadata holds playlist information
 type PlaylistInfoMetadata struct {
 	Tracks struct {
 		Total int `json:"total"`
@@ -208,13 +191,11 @@ type PlaylistInfoMetadata struct {
 	} `json:"owner"`
 }
 
-// PlaylistResponsePayload is the response for playlist requests
 type PlaylistResponsePayload struct {
 	PlaylistInfo PlaylistInfoMetadata `json:"playlist_info"`
 	TrackList    []AlbumTrackMetadata `json:"track_list"`
 }
 
-// ArtistInfoMetadata holds artist information
 type ArtistInfoMetadata struct {
 	ID         string `json:"id"`
 	Name       string `json:"name"`
@@ -223,7 +204,6 @@ type ArtistInfoMetadata struct {
 	Popularity int    `json:"popularity"`
 }
 
-// ArtistAlbumMetadata holds album info for artist discography
 type ArtistAlbumMetadata struct {
 	ID          string `json:"id"`
 	Name        string `json:"name"`
@@ -234,24 +214,20 @@ type ArtistAlbumMetadata struct {
 	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"`
 }
 
-// SearchResult represents search results
 type SearchResult struct {
 	Tracks []TrackMetadata `json:"tracks"`
 	Total  int             `json:"total"`
 }
 
-// SearchArtistResult represents an artist in search results
 type SearchArtistResult struct {
 	ID         string `json:"id"`
 	Name       string `json:"name"`
@@ -260,10 +236,29 @@ type SearchArtistResult struct {
 	Popularity int    `json:"popularity"`
 }
 
-// SearchAllResult represents combined search results for tracks and artists
+type SearchAlbumResult struct {
+	ID          string `json:"id"`
+	Name        string `json:"name"`
+	Artists     string `json:"artists"`
+	Images      string `json:"images"`
+	ReleaseDate string `json:"release_date"`
+	TotalTracks int    `json:"total_tracks"`
+	AlbumType   string `json:"album_type"`
+}
+
+type SearchPlaylistResult struct {
+	ID          string `json:"id"`
+	Name        string `json:"name"`
+	Owner       string `json:"owner"`
+	Images      string `json:"images"`
+	TotalTracks int    `json:"total_tracks"`
+}
+
 type SearchAllResult struct {
-	Tracks  []TrackMetadata      `json:"tracks"`
+	Tracks    []TrackMetadata        `json:"tracks"`
-	Artists []SearchArtistResult `json:"artists"`
+	Artists   []SearchArtistResult   `json:"artists"`
+	Albums    []SearchAlbumResult    `json:"albums"`
+	Playlists []SearchPlaylistResult `json:"playlists"`
 }
 
 type spotifyURI struct {
@@ -277,7 +272,6 @@ type accessTokenResponse struct {
 	TokenType   string      `json:"token_type"`
 }
 
-// Internal API response types
 type image struct {
 	URL string `json:"url"`
 }
@@ -303,7 +297,7 @@ type albumSimplified struct {
 	Images      []image     `json:"images"`
 	ExternalURL externalURL `json:"external_urls"`
 	Artists     []artist    `json:"artists"`
-	AlbumType   string      `json:"album_type"` // album, single, compilation
+	AlbumType   string      `json:"album_type"`
 }
 
 type trackFull struct {
@@ -318,7 +312,6 @@ type trackFull struct {
 	Artists     []artist        `json:"artists"`
 }
 
-// GetFilteredData fetches and formats Spotify data
 func (c *SpotifyMetadataClient) GetFilteredData(ctx context.Context, spotifyURL string, batch bool, delay time.Duration) (interface{}, error) {
 	parsed, err := parseSpotifyURI(spotifyURL)
 	if err != nil {
@@ -344,7 +337,6 @@ func (c *SpotifyMetadataClient) GetFilteredData(ctx context.Context, spotifyURL
 	}
 }
 
-// SearchTracks searches for tracks on Spotify
 func (c *SpotifyMetadataClient) SearchTracks(ctx context.Context, query string, limit int) (*SearchResult, error) {
 	token, err := c.getAccessToken(ctx)
 	if err != nil {
@@ -391,12 +383,9 @@ 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()
@@ -456,7 +445,6 @@ func (c *SpotifyMetadataClient) SearchAll(ctx context.Context, query string, tra
 		})
 	}
 
-	// Limit artists to artistLimit
 	artistCount := len(response.Artists.Items)
 	if artistCount > artistLimit {
 		artistCount = artistLimit
@@ -473,7 +461,6 @@ func (c *SpotifyMetadataClient) SearchAll(ctx context.Context, query string, tra
 		})
 	}
 
-	// Store in cache
 	c.cacheMu.Lock()
 	c.searchCache[cacheKey] = &cacheEntry{
 		data:      result,
@@ -510,7 +497,6 @@ 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()
@@ -518,7 +504,6 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 	}
 	c.cacheMu.RUnlock()
 
-	// Track item structure for pagination
 	type trackItem struct {
 		ID          string      `json:"id"`
 		Name        string      `json:"name"`
@@ -546,19 +531,25 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 	}
 
 	albumImage := firstImageURL(data.Images)
+
+	// Get first artist ID
+	var firstArtistId string
+	if len(data.Artists) > 0 {
+		firstArtistId = data.Artists[0].ID
+	}
+
 	info := AlbumInfoMetadata{
 		TotalTracks: data.TotalTracks,
 		Name:        data.Name,
 		ReleaseDate: data.ReleaseDate,
 		Artists:     joinArtists(data.Artists),
+		ArtistId:    firstArtistId,
 		Images:      albumImage,
 	}
 
-	// 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"`
@@ -580,7 +571,6 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 		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))
@@ -610,7 +600,6 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 		TrackList: tracks,
 	}
 
-	// Store in cache
 	c.cacheMu.Lock()
 	c.albumCache[albumID] = &cacheEntry{
 		data:      result,
@@ -621,10 +610,8 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 	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
+	const maxParallelISRC = 10
 
 	result := make(map[string]string)
 	var resultMu sync.Mutex
@@ -633,7 +620,6 @@ func (c *SpotifyMetadataClient) fetchISRCsParallel(ctx context.Context, trackIDs
 		return result
 	}
 
-	// Use semaphore to limit concurrent requests
 	sem := make(chan struct{}, maxParallelISRC)
 	var wg sync.WaitGroup
 
@@ -642,7 +628,6 @@ func (c *SpotifyMetadataClient) fetchISRCsParallel(ctx context.Context, trackIDs
 		go func(id string) {
 			defer wg.Done()
 
-			// Acquire semaphore
 			select {
 			case sem <- struct{}{}:
 				defer func() { <-sem }()
@@ -663,7 +648,6 @@ func (c *SpotifyMetadataClient) fetchISRCsParallel(ctx context.Context, trackIDs
 }
 
 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"`
@@ -689,10 +673,8 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 	info.Owner.Name = data.Name
 	info.Owner.Images = firstImageURL(data.Images)
 
-	// 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
@@ -716,7 +698,6 @@ 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 != "" {
@@ -728,7 +709,6 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 		}
 
 		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
 		}
@@ -768,7 +748,6 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 }
 
 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()
@@ -776,7 +755,6 @@ func (c *SpotifyMetadataClient) fetchArtist(ctx context.Context, artistID, token
 	}
 	c.cacheMu.RUnlock()
 
-	// Fetch artist info
 	var artistData struct {
 		ID        string  `json:"id"`
 		Name      string  `json:"name"`
@@ -799,7 +777,6 @@ func (c *SpotifyMetadataClient) fetchArtist(ctx context.Context, artistID, token
 		Popularity: artistData.Popularity,
 	}
 
-	// Fetch artist albums (all types: album, single, compilation)
 	albums := make([]ArtistAlbumMetadata, 0)
 	offset := 0
 	limit := 50
@@ -839,13 +816,11 @@ func (c *SpotifyMetadataClient) fetchArtist(ctx context.Context, artistID, token
 			})
 		}
 
-		// 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
 		}
@@ -856,7 +831,6 @@ func (c *SpotifyMetadataClient) fetchArtist(ctx context.Context, artistID, token
 		Albums:     albums,
 	}
 
-	// Store in cache
 	c.cacheMu.Lock()
 	c.artistCache[artistID] = &cacheEntry{
 		data:      result,
@@ -927,7 +901,6 @@ 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")
@@ -963,8 +936,7 @@ func (c *SpotifyMetadataClient) randomUserAgent() string {
 	c.rngMu.Lock()
 	defer c.rngMu.Unlock()
 
-	// Use Mac User-Agent format (same as PC version)
+	macMajor := c.rng.Intn(4) + 11
-	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
@@ -989,7 +961,6 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		return spotifyURI{}, errInvalidSpotifyURL
 	}
 
-	// Handle spotify: URI format
 	if strings.HasPrefix(trimmed, "spotify:") {
 		parts := strings.Split(trimmed, ":")
 		if len(parts) == 3 {
@@ -1000,13 +971,11 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		}
 	}
 
-	// Handle URL format
 	parsed, err := url.Parse(trimmed)
 	if err != nil {
 		return spotifyURI{}, err
 	}
 
-	// Handle embed.spotify.com URLs
 	if parsed.Host == "embed.spotify.com" {
 		if parsed.RawQuery == "" {
 			return spotifyURI{}, errInvalidSpotifyURL
@@ -1019,7 +988,6 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		return parseSpotifyURI(embedded)
 	}
 
-	// Handle plain ID (no scheme/host) - defaults to playlist
 	if parsed.Scheme == "" && parsed.Host == "" {
 		id := strings.Trim(strings.TrimSpace(parsed.Path), "/")
 		if id == "" {
@@ -1045,7 +1013,6 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		return spotifyURI{}, errInvalidSpotifyURL
 	}
 
-	// Skip intl- prefix if present
 	if strings.HasPrefix(parts[0], "intl-") {
 		parts = parts[1:]
 	}
@@ -1053,7 +1020,6 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		return spotifyURI{}, errInvalidSpotifyURL
 	}
 
-	// Handle standard URLs: /album/{id}, /track/{id}, /playlist/{id}, /artist/{id}
 	if len(parts) == 2 {
 		switch parts[0] {
 		case "album", "track", "playlist", "artist":
@@ -1061,7 +1027,6 @@ func parseSpotifyURI(input string) (spotifyURI, error) {
 		}
 	}
 
-	// Handle nested playlist URLs: /user/{user}/playlist/{id}
 	if len(parts) == 4 && parts[2] == "playlist" {
 		return spotifyURI{Type: "playlist", ID: parts[3]}, nil
 	}

ios/Runner/AppDelegate.swift

@@ -120,6 +120,12 @@ import Gobackend  // Import Go framework
             let itemId = args["item_id"] as! String
             GobackendClearItemProgress(itemId)
             return nil
+
+        case "cancelDownload":
+            let args = call.arguments as! [String: Any]
+            let itemId = args["item_id"] as! String
+            GobackendCancelDownload(itemId)
+            return nil
             
         case "setDownloadDirectory":
             let args = call.arguments as! [String: Any]
@@ -136,6 +142,27 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "checkDuplicatesBatch":
+            let args = call.arguments as! [String: Any]
+            let outputDir = args["output_dir"] as! String
+            let tracksJson = args["tracks"] as? String ?? "[]"
+            let response = GobackendCheckDuplicatesBatch(outputDir, tracksJson, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "preBuildDuplicateIndex":
+            let args = call.arguments as! [String: Any]
+            let outputDir = args["output_dir"] as! String
+            GobackendPreBuildDuplicateIndex(outputDir, &error)
+            if let error = error { throw error }
+            return nil
+            
+        case "invalidateDuplicateIndex":
+            let args = call.arguments as! [String: Any]
+            let outputDir = args["output_dir"] as! String
+            GobackendInvalidateDuplicateIndex(outputDir)
+            return nil
+            
         case "buildFilename":
             let args = call.arguments as! [String: Any]
             let template = args["template"] as! String
@@ -155,7 +182,8 @@ 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 = GobackendFetchLyrics(spotifyId, trackName, artistName, &error)
+            let durationMs = args["duration_ms"] as? Int64 ?? 0
+            let response = GobackendFetchLyrics(spotifyId, trackName, artistName, durationMs, &error)
             if let error = error { throw error }
             return response
             
@@ -165,7 +193,8 @@ import Gobackend  // Import Go framework
             let trackName = args["track_name"] as! String
             let artistName = args["artist_name"] as! String
             let filePath = args["file_path"] as? String ?? ""
-            let response = GobackendGetLyricsLRC(spotifyId, trackName, artistName, filePath, &error)
+            let durationMs = args["duration_ms"] as? Int64 ?? 0
+            let response = GobackendGetLyricsLRC(spotifyId, trackName, artistName, filePath, durationMs, &error)
             if let error = error { throw error }
             return response
             
@@ -193,7 +222,8 @@ import Gobackend  // Import Go framework
             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)
+            let filter = args["filter"] as? String ?? ""
+            let response = GobackendSearchDeezerAll(query, Int(trackLimit), Int(artistLimit), filter, &error)
             if let error = error { throw error }
             return response
 
@@ -219,6 +249,13 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
 
+        case "getDeezerExtendedMetadata":
+            let args = call.arguments as! [String: Any]
+            let trackId = args["track_id"] as! String
+            let response = GobackendGetDeezerExtendedMetadata(trackId, &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
@@ -234,6 +271,43 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "checkAvailabilityFromDeezerID":
+            let args = call.arguments as! [String: Any]
+            let deezerTrackId = args["deezer_track_id"] as! String
+            let response = GobackendCheckAvailabilityFromDeezerID(deezerTrackId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "checkAvailabilityByPlatformID":
+            let args = call.arguments as! [String: Any]
+            let platform = args["platform"] as! String
+            let entityType = args["entity_type"] as! String
+            let entityId = args["entity_id"] as! String
+            let response = GobackendCheckAvailabilityByPlatformID(platform, entityType, entityId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getSpotifyIDFromDeezerTrack":
+            let args = call.arguments as! [String: Any]
+            let deezerTrackId = args["deezer_track_id"] as! String
+            let response = GobackendGetSpotifyIDFromDeezerTrack(deezerTrackId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getTidalURLFromDeezerTrack":
+            let args = call.arguments as! [String: Any]
+            let deezerTrackId = args["deezer_track_id"] as! String
+            let response = GobackendGetTidalURLFromDeezerTrack(deezerTrackId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getAmazonURLFromDeezerTrack":
+            let args = call.arguments as! [String: Any]
+            let deezerTrackId = args["deezer_track_id"] as! String
+            let response = GobackendGetAmazonURLFromDeezerTrack(deezerTrackId, &error)
+            if let error = error { throw error }
+            return response
+            
         case "preWarmTrackCache":
             let args = call.arguments as! [String: Any]
             let tracksJson = args["tracks"] as! String
@@ -367,6 +441,14 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return nil
             
+        case "invokeExtensionAction":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let actionName = args["action"] as! String
+            let response = GobackendInvokeExtensionActionJSON(extensionId, actionName, &error)
+            if let error = error { throw error }
+            return response
+            
         case "searchTracksWithExtensions":
             let args = call.arguments as! [String: Any]
             let query = args["query"] as! String
@@ -381,6 +463,14 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "enrichTrackWithExtension":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let trackJson = args["track"] as? String ?? "{}"
+            let response = GobackendEnrichTrackWithExtensionJSON(extensionId, trackJson, &error)
+            if let error = error { throw error }
+            return response
+            
         case "removeExtension":
             let args = call.arguments as! [String: Any]
             let extensionId = args["extension_id"] as! String
@@ -503,6 +593,30 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return response
             
+        case "getAlbumWithExtension":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let albumId = args["album_id"] as! String
+            let response = GobackendGetAlbumWithExtensionJSON(extensionId, albumId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getPlaylistWithExtension":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let playlistId = args["playlist_id"] as! String
+            let response = GobackendGetPlaylistWithExtensionJSON(extensionId, playlistId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getArtistWithExtension":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let artistId = args["artist_id"] as! String
+            let response = GobackendGetArtistWithExtensionJSON(extensionId, artistId, &error)
+            if let error = error { throw error }
+            return response
+            
         // Extension Post-Processing API
         case "runPostProcessing":
             let args = call.arguments as! [String: Any]
@@ -558,6 +672,21 @@ import Gobackend  // Import Go framework
             if let error = error { throw error }
             return nil
             
+        // Extension Home Feed API
+        case "getExtensionHomeFeed":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let response = GobackendGetExtensionHomeFeedJSON(extensionId, &error)
+            if let error = error { throw error }
+            return response
+            
+        case "getExtensionBrowseCategories":
+            let args = call.arguments as! [String: Any]
+            let extensionId = args["extension_id"] as! String
+            let response = GobackendGetExtensionBrowseCategoriesJSON(extensionId, &error)
+            if let error = error { throw error }
+            return response
+            
         default:
             throw NSError(
                 domain: "SpotiFLAC",

ios/Runner/Info.plist

@@ -4,6 +4,23 @@
 <dict>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleLocalizations</key>
+	<array>
+		<string>en</string>
+		<string>de</string>
+		<string>es</string>
+		<string>fr</string>
+		<string>hi</string>
+		<string>id</string>
+		<string>ja</string>
+		<string>ko</string>
+		<string>nl</string>
+		<string>pt</string>
+		<string>ru</string>
+		<string>zh</string>
+		<string>zh-Hans</string>
+		<string>zh-Hant</string>
+	</array>
 	<key>CFBundleDisplayName</key>
 	<string>SpotiFLAC</string>
 	<key>CFBundleExecutable</key>

l10n.yaml

@@ -0,0 +1,6 @@
+arb-dir: lib/l10n/arb
+template-arb-file: app_en.arb
+output-localization-file: app_localizations.dart
+output-class: AppLocalizations
+output-dir: lib/l10n
+nullable-getter: false

lib/app.dart

@@ -1,13 +1,14 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:go_router/go_router.dart';
 import 'package:spotiflac_android/screens/main_shell.dart';
 import 'package:spotiflac_android/screens/setup_screen.dart';
 import 'package:spotiflac_android/providers/settings_provider.dart';
 import 'package:spotiflac_android/theme/dynamic_color_wrapper.dart';
+import 'package:spotiflac_android/l10n/app_localizations.dart';
 
 final _routerProvider = Provider<GoRouter>((ref) {
-  // Only watch isFirstLaunch to prevent router rebuild on other settings changes
   final isFirstLaunch = ref.watch(settingsProvider.select((s) => s.isFirstLaunch));
   
   return GoRouter(
@@ -31,6 +32,17 @@ class SpotiFLACApp extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final router = ref.watch(_routerProvider);
+    final localeString = ref.watch(settingsProvider.select((s) => s.locale));
+    
+    Locale? locale;
+    if (localeString != 'system') {
+      if (localeString.contains('_')) {
+        final parts = localeString.split('_');
+        locale = Locale(parts[0], parts[1]);
+      } else {
+        locale = Locale(localeString);
+      }
+    }
     
     return DynamicColorWrapper(
       builder: (lightTheme, darkTheme, themeMode) {
@@ -43,6 +55,14 @@ class SpotiFLACApp extends ConsumerWidget {
           themeAnimationDuration: const Duration(milliseconds: 300),
           themeAnimationCurve: Curves.easeInOut,
           routerConfig: router,
+          locale: locale,
+          localizationsDelegates: const [
+            AppLocalizations.delegate,
+            GlobalMaterialLocalizations.delegate,
+            GlobalWidgetsLocalizations.delegate,
+            GlobalCupertinoLocalizations.delegate,
+          ],
+          supportedLocales: AppLocalizations.supportedLocales,
         );
       },
     );

lib/constants/app_info.dart

@@ -1,8 +1,8 @@
 /// App version and info constants
 /// Update version here only - all other files will reference this
 class AppInfo {
-  static const String version = '3.0.0';
+static const String version = '3.3.5';
-  static const String buildNumber = '57';
+  static const String buildNumber = '70';
   static const String fullVersion = '$version+$buildNumber';
   
   

lib/l10n/l10n.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/material.dart';
+import 'package:spotiflac_android/l10n/app_localizations.dart';
+
+export 'package:spotiflac_android/l10n/app_localizations.dart';
+
+/// Extension to easily access AppLocalizations from BuildContext
+extension AppLocalizationsX on BuildContext {
+  /// Get the AppLocalizations instance
+  /// Usage: context.l10n.navHome
+  AppLocalizations get l10n => AppLocalizations.of(this);
+}

lib/l10n/supported_locales.dart

@@ -0,0 +1,34 @@
+// GENERATED FILE - DO NOT EDIT
+// Generated by: dart run tool/check_translations.dart 70
+// Only languages with >= 70% translation completion are included.
+// Translation is measured by comparing VALUES (not just key existence).
+//
+// To regenerate, run: dart run tool/check_translations.dart 70
+
+import 'package:flutter/widgets.dart';
+
+/// Minimum translation completion threshold used to filter languages.
+const int translationThreshold = 70;
+
+/// List of locales that meet the translation threshold.
+/// Only these languages will be available in the app.
+const List<Locale> filteredSupportedLocales = <Locale>[
+  Locale('en'),
+  Locale('ru'),
+  Locale('es', 'ES'),
+  Locale('id'),
+  Locale('pt', 'PT'),
+  Locale('ja'),
+  Locale('tr'),
+];
+
+/// Set of locale codes for quick lookup.
+const Set<String> filteredLocaleCodes = <String>{
+  'en',
+  'ru',
+  'es_ES',
+  'id',
+  'pt_PT',
+  'ja',
+  'tr',
+};

lib/main.dart

@@ -7,15 +7,18 @@ import 'package:spotiflac_android/providers/download_queue_provider.dart';
 import 'package:spotiflac_android/providers/extension_provider.dart';
 import 'package:spotiflac_android/services/notification_service.dart';
 import 'package:spotiflac_android/services/share_intent_service.dart';
+import 'package:spotiflac_android/services/cover_cache_manager.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   
-  // Initialize notification service
+  await CoverCacheManager.initialize();
-  await NotificationService().initialize();
+  debugPrint('CoverCacheManager initialized: ${CoverCacheManager.isInitialized}');
   
-  // Initialize share intent service
+  await Future.wait([
-  await ShareIntentService().initialize();
+    NotificationService().initialize(),
+    ShareIntentService().initialize(),
+  ]);
   
   runApp(
     ProviderScope(
@@ -40,6 +43,7 @@ class _EagerInitializationState extends ConsumerState<_EagerInitialization> {
   void initState() {
     super.initState();
     _initializeExtensions();
+    ref.read(downloadHistoryProvider);
   }
 
   Future<void> _initializeExtensions() async {
@@ -48,11 +52,9 @@ class _EagerInitializationState extends ConsumerState<_EagerInitialization> {
       final extensionsDir = '${appDir.path}/extensions';
       final dataDir = '${appDir.path}/extension_data';
       
-      // Create directories if needed
       await Directory(extensionsDir).create(recursive: true);
       await Directory(dataDir).create(recursive: true);
       
-      // Initialize extension system
       await ref.read(extensionProvider.notifier).initialize(extensionsDir, dataDir);
     } catch (e) {
       debugPrint('Failed to initialize extensions: $e');
@@ -61,8 +63,6 @@ class _EagerInitializationState extends ConsumerState<_EagerInitialization> {
 
   @override
   Widget build(BuildContext context) {
-    // Eagerly initialize download history provider to load from storage
-    ref.watch(downloadHistoryProvider);
     return widget.child;
   }
 }

lib/models/download_item.dart

@@ -3,23 +3,21 @@ import 'package:spotiflac_android/models/track.dart';
 
 part 'download_item.g.dart';
 
-/// Download status enum
 enum DownloadStatus {
   queued,
   downloading,
-  finalizing, // Embedding metadata, cover, lyrics
+  finalizing,
   completed,
   failed,
   skipped,
 }
 
-/// Error type enum for better error handling
 enum DownloadErrorType {
   unknown,
-  notFound,    // Track not found on any service
+  notFound,
-  rateLimit,   // Rate limited by service
+  rateLimit,
-  network,     // Network/connection error
+  network,
-  permission,  // File/folder permission error
+  permission,
 }
 
 @JsonSerializable()
@@ -29,7 +27,7 @@ class DownloadItem {
   final String service;
   final DownloadStatus status;
   final double progress;
-  final double speedMBps; // Download speed in MB/s
+  final double speedMBps;
   final String? filePath;
   final String? error;
   final DownloadErrorType? errorType;
@@ -78,7 +76,6 @@ class DownloadItem {
     );
   }
 
-  /// Get user-friendly error message based on error type
   String get errorMessage {
     if (error == null) return '';
     

lib/models/settings.dart

@@ -12,24 +12,29 @@ class AppSettings {
   final bool embedLyrics;
   final bool maxQualityCover;
   final bool isFirstLaunch;
-  final int concurrentDownloads; // 1 = sequential (default), max 3
+  final int concurrentDownloads;
-  final bool checkForUpdates; // Check for updates on app start
+  final bool checkForUpdates;
-  final String updateChannel; // stable, preview
+  final String updateChannel;
-  final bool hasSearchedBefore; // Hide helper text after first search
+  final bool hasSearchedBefore;
-  final String folderOrganization; // none, artist, album, artist_album
+  final String folderOrganization;
-  final String historyViewMode; // list, grid
+  final String historyViewMode;
-  final String historyFilterMode; // all, albums, singles
+  final String historyFilterMode;
-  final bool askQualityBeforeDownload; // Show quality picker before each download
+  final bool askQualityBeforeDownload;
-  final String spotifyClientId; // Custom Spotify client ID (empty = use default)
+  final String spotifyClientId;
-  final String spotifyClientSecret; // Custom Spotify client secret (empty = use default)
+  final String spotifyClientSecret;
-  final bool useCustomSpotifyCredentials; // Whether to use custom credentials (if set)
+  final bool useCustomSpotifyCredentials;
-  final String metadataSource; // spotify, deezer - source for search and metadata
+  final String metadataSource;
-  final bool enableLogging; // Enable detailed logging for debugging
+  final bool enableLogging;
-  final bool useExtensionProviders; // Use extension providers for downloads when available
+  final bool useExtensionProviders;
-  final String? searchProvider; // null/empty = default (Deezer/Spotify), otherwise extension ID
+  final String? searchProvider;
-  final bool separateSingles; // Separate singles/EPs into their own folder
+  final bool separateSingles;
-  final String albumFolderStructure; // artist_album or album_only
+  final String albumFolderStructure;
-  final bool showExtensionStore; // Show Extension Store tab in navigation
+  final bool showExtensionStore;
+  final String locale;
+  final String lyricsMode;
+  final String tidalHighFormat; // Format for Tidal HIGH quality: 'mp3_320' or 'opus_128'
+  final bool useAllFilesAccess; // Android 13+ only: enable MANAGE_EXTERNAL_STORAGE
+  final bool autoExportFailedDownloads; // Auto export failed downloads to TXT file
 
   const AppSettings({
     this.defaultService = 'tidal',
@@ -40,24 +45,29 @@ class AppSettings {
     this.embedLyrics = true,
     this.maxQualityCover = true,
     this.isFirstLaunch = true,
-    this.concurrentDownloads = 1, // Default: sequential (off)
+    this.concurrentDownloads = 1,
-    this.checkForUpdates = true, // Default: enabled
+    this.checkForUpdates = true,
-    this.updateChannel = 'stable', // Default: stable releases only
+    this.updateChannel = 'stable',
-    this.hasSearchedBefore = false, // Default: show helper text
+    this.hasSearchedBefore = false,
-    this.folderOrganization = 'none', // Default: no folder organization
+    this.folderOrganization = 'none',
-    this.historyViewMode = 'grid', // Default: grid view
+    this.historyViewMode = 'grid',
-    this.historyFilterMode = 'all', // Default: show all
+    this.historyFilterMode = 'all',
-    this.askQualityBeforeDownload = true, // Default: ask quality before download
+    this.askQualityBeforeDownload = true,
-    this.spotifyClientId = '', // Default: use built-in credentials
+    this.spotifyClientId = '',
-    this.spotifyClientSecret = '', // Default: use built-in credentials
+    this.spotifyClientSecret = '',
-    this.useCustomSpotifyCredentials = true, // Default: use custom if set
+    this.useCustomSpotifyCredentials = true,
-    this.metadataSource = 'deezer', // Default: Deezer (no rate limit)
+    this.metadataSource = 'deezer',
-    this.enableLogging = false, // Default: disabled for performance
+    this.enableLogging = false,
-    this.useExtensionProviders = true, // Default: use extensions when available
+    this.useExtensionProviders = true,
-    this.searchProvider, // Default: null (use Deezer/Spotify)
+    this.searchProvider,
-    this.separateSingles = false, // Default: disabled
+    this.separateSingles = false,
-    this.albumFolderStructure = 'artist_album', // Default: Albums/Artist/Album
+    this.albumFolderStructure = 'artist_album',
-    this.showExtensionStore = true, // Default: show store
+    this.showExtensionStore = true,
+    this.locale = 'system',
+    this.lyricsMode = 'embed',
+    this.tidalHighFormat = 'mp3_320',
+    this.useAllFilesAccess = false,
+    this.autoExportFailedDownloads = false,
   });
 
   AppSettings copyWith({
@@ -84,10 +94,15 @@ class AppSettings {
     bool? enableLogging,
     bool? useExtensionProviders,
     String? searchProvider,
-    bool clearSearchProvider = false, // Set to true to clear searchProvider to null
+    bool clearSearchProvider = false,
     bool? separateSingles,
     String? albumFolderStructure,
     bool? showExtensionStore,
+    String? locale,
+    String? lyricsMode,
+    String? tidalHighFormat,
+    bool? useAllFilesAccess,
+    bool? autoExportFailedDownloads,
   }) {
     return AppSettings(
       defaultService: defaultService ?? this.defaultService,
@@ -116,6 +131,11 @@ class AppSettings {
       separateSingles: separateSingles ?? this.separateSingles,
       albumFolderStructure: albumFolderStructure ?? this.albumFolderStructure,
       showExtensionStore: showExtensionStore ?? this.showExtensionStore,
+      locale: locale ?? this.locale,
+      lyricsMode: lyricsMode ?? this.lyricsMode,
+      tidalHighFormat: tidalHighFormat ?? this.tidalHighFormat,
+      useAllFilesAccess: useAllFilesAccess ?? this.useAllFilesAccess,
+      autoExportFailedDownloads: autoExportFailedDownloads ?? this.autoExportFailedDownloads,
     );
   }
 

lib/models/settings.g.dart

@@ -32,8 +32,15 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   useExtensionProviders: json['useExtensionProviders'] as bool? ?? true,
   searchProvider: json['searchProvider'] as String?,
   separateSingles: json['separateSingles'] as bool? ?? false,
-  albumFolderStructure: json['albumFolderStructure'] as String? ?? 'artist_album',
+  albumFolderStructure:
+      json['albumFolderStructure'] as String? ?? 'artist_album',
   showExtensionStore: json['showExtensionStore'] as bool? ?? true,
+  locale: json['locale'] as String? ?? 'system',
+  lyricsMode: json['lyricsMode'] as String? ?? 'embed',
+  tidalHighFormat: json['tidalHighFormat'] as String? ?? 'mp3_320',
+  useAllFilesAccess: json['useAllFilesAccess'] as bool? ?? false,
+  autoExportFailedDownloads:
+      json['autoExportFailedDownloads'] as bool? ?? false,
 );
 
 Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
@@ -64,4 +71,9 @@ Map<String, dynamic> _$AppSettingsToJson(AppSettings instance) =>
       'separateSingles': instance.separateSingles,
       'albumFolderStructure': instance.albumFolderStructure,
       'showExtensionStore': instance.showExtensionStore,
+      'locale': instance.locale,
+      'lyricsMode': instance.lyricsMode,
+      'tidalHighFormat': instance.tidalHighFormat,
+      'useAllFilesAccess': instance.useAllFilesAccess,
+      'autoExportFailedDownloads': instance.autoExportFailedDownloads,
     };

lib/models/theme_settings.dart

@@ -9,7 +9,6 @@ const String kUseAmoledKey = 'use_amoled';
 /// Default Spotify green color for fallback
 const int kDefaultSeedColor = 0xFF1DB954;
 
-/// Theme settings model for Material Expressive 3
 class ThemeSettings {
   final ThemeMode themeMode;
   final bool useDynamicColor;
@@ -23,10 +22,8 @@ class ThemeSettings {
     this.useAmoled = false,
   });
 
-  /// Get seed color as Color object
   Color get seedColor => Color(seedColorValue);
 
-  /// Create a copy with updated values
   ThemeSettings copyWith({
     ThemeMode? themeMode,
     bool? useDynamicColor,
@@ -41,7 +38,6 @@ class ThemeSettings {
     );
   }
 
-  /// Convert to JSON map for persistence
   Map<String, dynamic> toJson() => {
         kThemeModeKey: themeMode.name,
         kUseDynamicColorKey: useDynamicColor,
@@ -49,7 +45,6 @@ class ThemeSettings {
         kUseAmoledKey: useAmoled,
       };
 
-  /// Create from JSON map
   factory ThemeSettings.fromJson(Map<String, dynamic> json) {
     return ThemeSettings(
       themeMode: _themeModeFromString(json[kThemeModeKey] as String?),
@@ -74,7 +69,6 @@ class ThemeSettings {
       themeMode.hashCode ^ useDynamicColor.hashCode ^ seedColorValue.hashCode ^ useAmoled.hashCode;
 }
 
-/// Helper to convert string to ThemeMode
 ThemeMode _themeModeFromString(String? value) {
   if (value == null) return ThemeMode.system;
   return ThemeMode.values.firstWhere(

lib/models/track.dart

@@ -2,7 +2,6 @@ import 'package:json_annotation/json_annotation.dart';
 
 part 'track.g.dart';
 
-/// Track model representing a music track
 @JsonSerializable()
 class Track {
   final String id;
@@ -18,8 +17,9 @@ class Track {
   final String? releaseDate;
   final String? deezerId;
   final ServiceAvailability? availability;
-  final String? source; // Extension ID that provided this track (null for built-in sources)
+  final String? source;
-  final String? albumType; // album, single, ep, compilation (from metadata API)
+  final String? albumType;
+  final String? itemType;
 
   const Track({
     required this.id,
@@ -37,15 +37,22 @@ class Track {
     this.availability,
     this.source,
     this.albumType,
+    this.itemType,
   });
 
-  /// Check if this track is a single (based on album_type metadata)
   bool get isSingle => albumType == 'single' || albumType == 'ep';
+  
+  bool get isAlbumItem => itemType == 'album';
+  
+  bool get isPlaylistItem => itemType == 'playlist';
+  
+  bool get isArtistItem => itemType == 'artist';
+  
+  bool get isCollection => isAlbumItem || isPlaylistItem || isArtistItem;
 
   factory Track.fromJson(Map<String, dynamic> json) => _$TrackFromJson(json);
   Map<String, dynamic> toJson() => _$TrackToJson(this);
   
-  /// Check if this track is from an extension
   bool get isFromExtension => source != null && source!.isNotEmpty;
 }
 

lib/models/track.g.dart

@@ -26,6 +26,7 @@ Track _$TrackFromJson(Map<String, dynamic> json) => Track(
         ),
   source: json['source'] as String?,
   albumType: json['albumType'] as String?,
+  itemType: json['itemType'] as String?,
 );
 
 Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
@@ -44,6 +45,7 @@ Map<String, dynamic> _$TrackToJson(Track instance) => <String, dynamic>{
   'availability': instance.availability,
   'source': instance.source,
   'albumType': instance.albumType,
+  'itemType': instance.itemType,
 };
 
 ServiceAvailability _$ServiceAvailabilityFromJson(Map<String, dynamic> json) =>