feat: add extended metadata (genre, label, copyright) support

- Add genre, label, copyright fields to ExtTrackMetadata and DownloadResponse
- Add utils.randomUserAgent() for extensions to get random User-Agent strings
- Fix VM race condition panic by adding mutex locks to all provider methods
- Fix Tidal release date fallback when req.ReleaseDate is empty
- Display genre, label, copyright in track metadata screen
- Store extended metadata in download history for persistence
- Add trackGenre, trackLabel, trackCopyright localization strings

lib/l10n/app_localizations.dart

@@ -1688,6 +1688,12 @@ abstract class AppLocalizations {
   /// **'Found {count} tracks in CSV. Add them to download queue?'**
   String dialogImportPlaylistMessage(int count);
 
+  /// Label shown in quality picker for CSV import
+  ///
+  /// In en, this message translates to:
+  /// **'{count} tracks from CSV'**
+  String csvImportTracks(int count);
+
   /// Snackbar - track added to download queue
   ///
   /// In en, this message translates to:
@@ -2870,6 +2876,24 @@ abstract class AppLocalizations {
   /// **'Release date'**
   String get trackReleaseDate;
 
+  /// Metadata label - music genre
+  ///
+  /// In en, this message translates to:
+  /// **'Genre'**
+  String get trackGenre;
+
+  /// Metadata label - record label
+  ///
+  /// In en, this message translates to:
+  /// **'Label'**
+  String get trackLabel;
+
+  /// Metadata label - copyright information
+  ///
+  /// In en, this message translates to:
+  /// **'Copyright'**
+  String get trackCopyright;
+
   /// Metadata label - download date
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -910,6 +910,11 @@ class AppLocalizationsDe extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1584,6 +1589,15 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_en.dart

@@ -897,6 +897,11 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_es.dart

@@ -897,6 +897,11 @@ class AppLocalizationsEs extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_fr.dart

@@ -897,6 +897,11 @@ class AppLocalizationsFr extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_hi.dart

@@ -897,6 +897,11 @@ class AppLocalizationsHi extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_id.dart

@@ -903,6 +903,11 @@ class AppLocalizationsId extends AppLocalizations {
     return 'Ditemukan $count lagu di CSV. Tambahkan ke antrian unduhan?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Menambahkan \"$trackName\" ke antrian';
@@ -1581,6 +1586,15 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Tanggal rilis';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Diunduh';
 

lib/l10n/app_localizations_ja.dart

@@ -897,6 +897,11 @@ class AppLocalizationsJa extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_ko.dart

@@ -897,6 +897,11 @@ class AppLocalizationsKo extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_nl.dart

@@ -897,6 +897,11 @@ class AppLocalizationsNl extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_pt.dart

@@ -897,6 +897,11 @@ class AppLocalizationsPt extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/app_localizations_ru.dart

@@ -919,6 +919,11 @@ class AppLocalizationsRu extends AppLocalizations {
     return 'Найдено $count треков в CSV. Добавить их в очередь загрузки?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return '\"$trackName\" добавлен в очередь';
@@ -1603,6 +1608,15 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Дата выхода';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Скачано';
 

lib/l10n/app_localizations_zh.dart

@@ -897,6 +897,11 @@ class AppLocalizationsZh extends AppLocalizations {
     return 'Found $count tracks in CSV. Add them to download queue?';
   }
 
+  @override
+  String csvImportTracks(int count) {
+    return '$count tracks from CSV';
+  }
+
   @override
   String snackbarAddedToQueue(String trackName) {
     return 'Added \"$trackName\" to queue';
@@ -1571,6 +1576,15 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get trackReleaseDate => 'Release date';
 
+  @override
+  String get trackGenre => 'Genre';
+
+  @override
+  String get trackLabel => 'Label';
+
+  @override
+  String get trackCopyright => 'Copyright';
+
   @override
   String get trackDownloaded => 'Downloaded';
 

lib/l10n/arb/app_en.arb

@@ -619,6 +619,13 @@
   "dialogImportPlaylistTitle": "Import Playlist",
   "@dialogImportPlaylistTitle": {"description": "Dialog title - import CSV playlist"},
   "dialogImportPlaylistMessage": "Found {count} tracks in CSV. Add them to download queue?",
+  "csvImportTracks": "{count} tracks from CSV",
+  "@csvImportTracks": {
+    "description": "Label shown in quality picker for CSV import",
+    "placeholders": {
+      "count": {"type": "int"}
+    }
+  },
   "@dialogImportPlaylistMessage": {
     "description": "Dialog message - import playlist confirmation",
     "placeholders": {
@@ -1153,6 +1160,12 @@
   "@trackAudioQuality": {"description": "Metadata label - audio quality"},
   "trackReleaseDate": "Release date",
   "@trackReleaseDate": {"description": "Metadata label - release date"},
+  "trackGenre": "Genre",
+  "@trackGenre": {"description": "Metadata label - music genre"},
+  "trackLabel": "Label",
+  "@trackLabel": {"description": "Metadata label - record label"},
+  "trackCopyright": "Copyright",
+  "@trackCopyright": {"description": "Metadata label - copyright information"},
   "trackDownloaded": "Downloaded",
   "@trackDownloaded": {"description": "Metadata label - download date"},
   "trackCopyLyrics": "Copy lyrics",

lib/providers/download_queue_provider.dart

@@ -45,6 +45,9 @@ class DownloadHistoryItem {
   final String? quality;
   final int? bitDepth;
   final int? sampleRate;
+  final String? genre;
+  final String? label;
+  final String? copyright;
 
   const DownloadHistoryItem({
     required this.id,
@@ -65,6 +68,9 @@ class DownloadHistoryItem {
     this.quality,
     this.bitDepth,
     this.sampleRate,
+    this.genre,
+    this.label,
+    this.copyright,
   });
 
   Map<String, dynamic> toJson() => {
@@ -86,6 +92,9 @@ class DownloadHistoryItem {
     'quality': quality,
     'bitDepth': bitDepth,
     'sampleRate': sampleRate,
+    'genre': genre,
+    'label': label,
+    'copyright': copyright,
   };
 
   factory DownloadHistoryItem.fromJson(Map<String, dynamic> json) =>
@@ -108,6 +117,9 @@ class DownloadHistoryItem {
         quality: json['quality'] as String?,
         bitDepth: json['bitDepth'] as int?,
         sampleRate: json['sampleRate'] as int?,
+        genre: json['genre'] as String?,
+        label: json['label'] as String?,
+        copyright: json['copyright'] as String?,
       );
 }
 
@@ -1016,7 +1028,13 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
   }
 
   /// Embed metadata and cover to a FLAC file after M4A conversion
-  Future<void> _embedMetadataAndCover(String flacPath, Track track) async {
+  Future<void> _embedMetadataAndCover(
+    String flacPath, 
+    Track track, {
+    String? genre,
+    String? label,
+    String? copyright,
+  }) async {
     final settings = ref.read(settingsProvider);
     
     String? coverPath;
@@ -1083,6 +1101,20 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         metadata['ISRC'] = track.isrc!;
       }
 
+      // Extended metadata from enrichment (genre, label, copyright)
+      if (genre != null && genre.isNotEmpty) {
+        metadata['GENRE'] = genre;
+        _log.d('Adding GENRE: $genre');
+      }
+      if (label != null && label.isNotEmpty) {
+        metadata['ORGANIZATION'] = label;
+        _log.d('Adding ORGANIZATION (label): $label');
+      }
+      if (copyright != null && copyright.isNotEmpty) {
+        metadata['COPYRIGHT'] = copyright;
+        _log.d('Adding COPYRIGHT: $copyright');
+      }
+
       _log.d('Metadata map content: $metadata');
 
       try {
@@ -1809,7 +1841,22 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
                       );
                     }
 
-                    await _embedMetadataAndCover(flacPath, finalTrack);
+                    // Get extended metadata from backend response
+                    final backendGenre = result['genre'] as String?;
+                    final backendLabel = result['label'] as String?;
+                    final backendCopyright = result['copyright'] as String?;
+                    
+                    if (backendGenre != null || backendLabel != null || backendCopyright != null) {
+                      _log.d('Extended metadata from backend - Genre: $backendGenre, Label: $backendLabel, Copyright: $backendCopyright');
+                    }
+
+                    await _embedMetadataAndCover(
+                      flacPath, 
+                      finalTrack,
+                      genre: backendGenre ?? genre,
+                      label: backendLabel ?? label,
+                      copyright: backendCopyright,
+                    );
                     _log.d('Metadata and cover embedded successfully');
                   } catch (e) {
                     _log.w('Warning: Failed to embed metadata/cover: $e');
@@ -1920,6 +1967,9 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           final backendBitDepth = result['actual_bit_depth'] as int?;
           final backendSampleRate = result['actual_sample_rate'] as int?;
           final backendISRC = result['isrc'] as String?;
+          final backendGenre = result['genre'] as String?;
+          final backendLabel = result['label'] as String?;
+          final backendCopyright = result['copyright'] as String?;
 
           _log.d('Saving to history - coverUrl: ${trackToDownload.coverUrl}');
 
@@ -1970,6 +2020,9 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
                   quality: actualQuality,
                   bitDepth: historyBitDepth,
                   sampleRate: historySampleRate,
+                  genre: backendGenre,
+                  label: backendLabel,
+                  copyright: backendCopyright,
                 ),
               );
 

lib/screens/home_tab.dart

@@ -355,37 +355,64 @@ class _HomeTabState extends ConsumerState<HomeTab> with AutomaticKeepAliveClient
       // ignore: use_build_context_synchronously
       final l10n = context.l10n;
       
-      final confirmed = await showDialog<bool>(
-        context: this.context,
-        builder: (dialogCtx) => AlertDialog(
-          title: Text(l10n.dialogImportPlaylistTitle),
-          content: Text(l10n.dialogImportPlaylistMessage(tracks.length)),
-          actions: [
-            TextButton(
-              onPressed: () => Navigator.pop(dialogCtx, false),
-              child: Text(l10n.dialogCancel),
-            ),
-            FilledButton(
-              onPressed: () => Navigator.pop(dialogCtx, true),
-              child: Text(l10n.dialogImport),
-            ),
-          ],
-        ),
-      );
-
-      if (confirmed == true) {
-        ref.read(downloadQueueProvider.notifier).addMultipleToQueue(tracks, settings.defaultService);
-        if (mounted) {
-           ScaffoldMessenger.of(this.context).showSnackBar(
-            SnackBar(
-              content: Text(l10n.snackbarAddedTracksToQueue(tracks.length)),
-              action: SnackBarAction(
-                label: l10n.snackbarViewQueue,
-                onPressed: () {
-                },
+      // Show quality picker if enabled in settings
+      if (settings.askQualityBeforeDownload) {
+        DownloadServicePicker.show(
+          this.context,
+          trackName: l10n.csvImportTracks(tracks.length),
+          artistName: l10n.dialogImportPlaylistTitle,
+          onSelect: (quality, service) {
+            ref.read(downloadQueueProvider.notifier).addMultipleToQueue(
+              tracks, 
+              service, 
+              qualityOverride: quality,
+            );
+            if (mounted) {
+              ScaffoldMessenger.of(this.context).showSnackBar(
+                SnackBar(
+                  content: Text(l10n.snackbarAddedTracksToQueue(tracks.length)),
+                  action: SnackBarAction(
+                    label: l10n.snackbarViewQueue,
+                    onPressed: () {},
+                  ),
+                ),
+              );
+            }
+          },
+        );
+      } else {
+        // Use default settings without quality picker
+        final confirmed = await showDialog<bool>(
+          context: this.context,
+          builder: (dialogCtx) => AlertDialog(
+            title: Text(l10n.dialogImportPlaylistTitle),
+            content: Text(l10n.dialogImportPlaylistMessage(tracks.length)),
+            actions: [
+              TextButton(
+                onPressed: () => Navigator.pop(dialogCtx, false),
+                child: Text(l10n.dialogCancel),
               ),
-            ),
-          );
+              FilledButton(
+                onPressed: () => Navigator.pop(dialogCtx, true),
+                child: Text(l10n.dialogImport),
+              ),
+            ],
+          ),
+        );
+
+        if (confirmed == true) {
+          ref.read(downloadQueueProvider.notifier).addMultipleToQueue(tracks, settings.defaultService);
+          if (mounted) {
+            ScaffoldMessenger.of(this.context).showSnackBar(
+              SnackBar(
+                content: Text(l10n.snackbarAddedTracksToQueue(tracks.length)),
+                action: SnackBarAction(
+                  label: l10n.snackbarViewQueue,
+                  onPressed: () {},
+                ),
+              ),
+            );
+          }
         }
       }
     }

lib/screens/track_metadata_screen.dart

@@ -119,6 +119,9 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
   int? get discNumber => item.discNumber;
   String? get releaseDate => item.releaseDate;
   String? get isrc => item.isrc;
+  String? get genre => item.genre;
+  String? get label => item.label;
+  String? get copyright => item.copyright;
   
   String get cleanFilePath {
     final path = item.filePath;
@@ -519,6 +522,12 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
         _MetadataItem(context.l10n.trackAudioQuality, audioQualityStr),
       if (releaseDate != null && releaseDate!.isNotEmpty)
         _MetadataItem(context.l10n.trackReleaseDate, releaseDate!),
+      if (genre != null && genre!.isNotEmpty)
+        _MetadataItem(context.l10n.trackGenre, genre!),
+      if (label != null && label!.isNotEmpty)
+        _MetadataItem(context.l10n.trackLabel, label!),
+      if (copyright != null && copyright!.isNotEmpty)
+        _MetadataItem(context.l10n.trackCopyright, copyright!),
       if (isrc != null && isrc!.isNotEmpty)
         _MetadataItem('ISRC', isrc!),
     ];