feat: add separate filename format for singles and EPs (#271)

Add singleFilenameFormat setting so singles/EPs can use a different filename template than albums. The format editor is reused with custom title/description. Dart selects the correct format based on track.isSingle before passing to Go, so no backend changes needed. Also fix isSingle getter to include all EPs regardless of totalTracks. Closes #271

lib/l10n/app_localizations.dart

@@ -256,6 +256,18 @@ abstract class AppLocalizations {
   /// **'Filename Format'**
   String get downloadFilenameFormat;
 
+  /// Setting for output filename pattern for singles/EPs
+  ///
+  /// In en, this message translates to:
+  /// **'Single Filename Format'**
+  String get downloadSingleFilenameFormat;
+
+  /// Subtitle description for single filename format setting
+  ///
+  /// In en, this message translates to:
+  /// **'Filename pattern for singles and EPs. Uses the same tags as the album format.'**
+  String get downloadSingleFilenameFormatDescription;
+
   /// Title of the folder organization picker bottom sheet
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -76,6 +76,13 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Dateinamenformat';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Ordnerstruktur';
 

lib/l10n/app_localizations_en.dart

@@ -75,6 +75,13 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/app_localizations_es.dart

@@ -75,6 +75,13 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/app_localizations_fr.dart

@@ -75,6 +75,13 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Nom du fichier';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Organisation du dossier';
 

lib/l10n/app_localizations_hi.dart

@@ -75,6 +75,13 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/app_localizations_id.dart

@@ -76,6 +76,13 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Format Nama File';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Organisasi Folder';
 

lib/l10n/app_localizations_ja.dart

@@ -75,6 +75,13 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'ファイル名の形式';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'フォルダ構成';
 

lib/l10n/app_localizations_ko.dart

@@ -74,6 +74,13 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get downloadFilenameFormat => '파일 이름 형식';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => '폴더 분류 형식';
 

lib/l10n/app_localizations_nl.dart

@@ -75,6 +75,13 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/app_localizations_pt.dart

@@ -75,6 +75,13 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/app_localizations_ru.dart

@@ -76,6 +76,13 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Формат имени файла';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Организация папок';
 

lib/l10n/app_localizations_tr.dart

@@ -76,6 +76,13 @@ class AppLocalizationsTr extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Dosya adı formatı';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Dosya Organizasyonu';
 

lib/l10n/app_localizations_zh.dart

@@ -75,6 +75,13 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get downloadFilenameFormat => 'Filename Format';
 
+  @override
+  String get downloadSingleFilenameFormat => 'Single Filename Format';
+
+  @override
+  String get downloadSingleFilenameFormatDescription =>
+      'Filename pattern for singles and EPs. Uses the same tags as the album format.';
+
   @override
   String get downloadFolderOrganization => 'Folder Organization';
 

lib/l10n/arb/app_en.arb

@@ -89,6 +89,14 @@
   "@downloadFilenameFormat": {
     "description": "Setting for output filename pattern"
   },
+  "downloadSingleFilenameFormat": "Single Filename Format",
+  "@downloadSingleFilenameFormat": {
+    "description": "Setting for output filename pattern for singles/EPs"
+  },
+  "downloadSingleFilenameFormatDescription": "Filename pattern for singles and EPs. Uses the same tags as the album format.",
+  "@downloadSingleFilenameFormatDescription": {
+    "description": "Subtitle description for single filename format setting"
+  },
   "downloadFolderOrganization": "Folder Organization",
   "@downloadFolderOrganization": {
     "description": "Setting for folder structure"

lib/models/settings.dart

@@ -35,6 +35,7 @@ class AppSettings {
   final String? searchProvider;
   final String? homeFeedProvider;
   final bool separateSingles;
+  final String singleFilenameFormat;
   final String albumFolderStructure;
   final bool showExtensionStore;
   final String locale;
@@ -108,6 +109,7 @@ class AppSettings {
     this.searchProvider,
     this.homeFeedProvider,
     this.separateSingles = false,
+    this.singleFilenameFormat = '{title} - {artist}',
     this.albumFolderStructure = 'artist_album',
     this.showExtensionStore = true,
     this.locale = 'system',
@@ -170,6 +172,7 @@ class AppSettings {
     String? homeFeedProvider,
     bool clearHomeFeedProvider = false,
     bool? separateSingles,
+    String? singleFilenameFormat,
     String? albumFolderStructure,
     bool? showExtensionStore,
     String? locale,
@@ -232,6 +235,7 @@ class AppSettings {
           ? null
           : (homeFeedProvider ?? this.homeFeedProvider),
       separateSingles: separateSingles ?? this.separateSingles,
+      singleFilenameFormat: singleFilenameFormat ?? this.singleFilenameFormat,
       albumFolderStructure: albumFolderStructure ?? this.albumFolderStructure,
       showExtensionStore: showExtensionStore ?? this.showExtensionStore,
       locale: locale ?? this.locale,

lib/models/settings.g.dart

@@ -15,7 +15,7 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   downloadTreeUri: json['downloadTreeUri'] as String? ?? '',
   autoFallback: json['autoFallback'] as bool? ?? true,
   embedMetadata: json['embedMetadata'] as bool? ?? true,
-  artistTagMode: json['artistTagMode'] as String? ?? 'joined',
+  artistTagMode: json['artistTagMode'] as String? ?? artistTagModeJoined,
   embedLyrics: json['embedLyrics'] as bool? ?? true,
   maxQualityCover: json['maxQualityCover'] as bool? ?? true,
   isFirstLaunch: json['isFirstLaunch'] as bool? ?? true,
@@ -37,6 +37,8 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   searchProvider: json['searchProvider'] as String?,
   homeFeedProvider: json['homeFeedProvider'] as String?,
   separateSingles: json['separateSingles'] as bool? ?? false,
+  singleFilenameFormat:
+      json['singleFilenameFormat'] as String? ?? '{title} - {artist}',
   albumFolderStructure:
       json['albumFolderStructure'] as String? ?? 'artist_album',
   showExtensionStore: json['showExtensionStore'] as bool? ?? true,
@@ -104,6 +106,7 @@ Map<String, dynamic> _$AppSettingsToJson(
   'searchProvider': instance.searchProvider,
   'homeFeedProvider': instance.homeFeedProvider,
   'separateSingles': instance.separateSingles,
+  'singleFilenameFormat': instance.singleFilenameFormat,
   'albumFolderStructure': instance.albumFolderStructure,
   'showExtensionStore': instance.showExtensionStore,
   'locale': instance.locale,

lib/models/track.dart

@@ -49,26 +49,24 @@ class Track {
   bool get isSingle {
     switch (albumType?.toLowerCase()) {
       case 'single':
-        return true;
       case 'ep':
-        final count = totalTracks;
-        return count == null || count <= 1;
+        return true;
       default:
         return false;
     }
   }
-  
+
   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);
-  
+
   bool get isFromExtension => source != null && source!.isNotEmpty;
 }
 

lib/providers/download_queue_provider.dart

@@ -1104,6 +1104,7 @@ class DownloadQueueState {
   final bool isPaused;
   final String outputDir;
   final String filenameFormat;
+  final String singleFilenameFormat;
   final String audioQuality;
   final bool autoFallback;
   final int concurrentDownloads;
@@ -1115,6 +1116,7 @@ class DownloadQueueState {
     this.isPaused = false,
     this.outputDir = '',
     this.filenameFormat = '{artist} - {title}',
+    this.singleFilenameFormat = '{title} - {artist}',
     this.audioQuality = 'LOSSLESS',
     this.autoFallback = true,
     this.concurrentDownloads = 1,
@@ -1127,6 +1129,7 @@ class DownloadQueueState {
     bool? isPaused,
     String? outputDir,
     String? filenameFormat,
+    String? singleFilenameFormat,
     String? audioQuality,
     bool? autoFallback,
     int? concurrentDownloads,
@@ -1140,6 +1143,7 @@ class DownloadQueueState {
       isPaused: isPaused ?? this.isPaused,
       outputDir: outputDir ?? this.outputDir,
       filenameFormat: filenameFormat ?? this.filenameFormat,
+      singleFilenameFormat: singleFilenameFormat ?? this.singleFilenameFormat,
       audioQuality: audioQuality ?? this.audioQuality,
       autoFallback: autoFallback ?? this.autoFallback,
       concurrentDownloads: concurrentDownloads ?? this.concurrentDownloads,
@@ -2256,6 +2260,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           ? settings.downloadDirectory
           : state.outputDir,
       filenameFormat: settings.filenameFormat,
+      singleFilenameFormat: settings.singleFilenameFormat,
       audioQuality: settings.audioQuality,
       autoFallback: settings.autoFallback,
       concurrentDownloads: concurrentDownloads,
@@ -3842,16 +3847,18 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
       String? safBaseName;
       String safOutputExt = _determineOutputExt(quality, item.service);
       if (isSafMode) {
-        final baseName =
-            await PlatformBridge.buildFilename(state.filenameFormat, {
-              'title': trackToDownload.name,
-              'artist': trackToDownload.artistName,
-              'album': trackToDownload.albumName,
-              'track': trackToDownload.trackNumber ?? 0,
-              'disc': trackToDownload.discNumber ?? 0,
-              'year': _extractYear(trackToDownload.releaseDate) ?? '',
-              'date': trackToDownload.releaseDate ?? '',
-            });
+        final effectiveFormat = trackToDownload.isSingle
+            ? state.singleFilenameFormat
+            : state.filenameFormat;
+        final baseName = await PlatformBridge.buildFilename(effectiveFormat, {
+          'title': trackToDownload.name,
+          'artist': trackToDownload.artistName,
+          'album': trackToDownload.albumName,
+          'track': trackToDownload.trackNumber ?? 0,
+          'disc': trackToDownload.discNumber ?? 0,
+          'year': _extractYear(trackToDownload.releaseDate) ?? '',
+          'date': trackToDownload.releaseDate ?? '',
+        });
         final sanitized = await PlatformBridge.sanitizeFilename(baseName);
         safBaseName = sanitized;
         safFileName = '$sanitized$safOutputExt';
@@ -4214,7 +4221,9 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
               ? (trackToDownload.coverUrl ?? '')
               : '',
           outputDir: outputDir,
-          filenameFormat: state.filenameFormat,
+          filenameFormat: trackToDownload.isSingle
+              ? state.singleFilenameFormat
+              : state.filenameFormat,
           quality: quality,
           embedMetadata: metadataEmbeddingEnabled,
           artistTagMode: settings.artistTagMode,

lib/providers/settings_provider.dart

@@ -196,6 +196,11 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
+  void setSingleFilenameFormat(String format) {
+    state = state.copyWith(singleFilenameFormat: format);
+    _saveSettings();
+  }
+
   void setDownloadDirectory(String directory) {
     state = state.copyWith(downloadDirectory: directory);
     _saveSettings();

lib/screens/settings/download_settings_page.dart

@@ -592,6 +592,22 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                       settings.filenameFormat,
                     ),
                   ),
+                  SettingsItem(
+                    icon: Icons.music_note_outlined,
+                    title: context.l10n.downloadSingleFilenameFormat,
+                    subtitle: settings.singleFilenameFormat,
+                    onTap: () => _showFormatEditor(
+                      context,
+                      ref,
+                      settings.singleFilenameFormat,
+                      onSave: ref
+                          .read(settingsProvider.notifier)
+                          .setSingleFilenameFormat,
+                      title: context.l10n.downloadSingleFilenameFormat,
+                      description:
+                          context.l10n.downloadSingleFilenameFormatDescription,
+                    ),
+                  ),
                   SettingsItem(
                     icon: Icons.folder_outlined,
                     title: context.l10n.downloadDirectory,
@@ -952,7 +968,14 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
     );
   }
 
-  void _showFormatEditor(BuildContext context, WidgetRef ref, String current) {
+  void _showFormatEditor(
+    BuildContext context,
+    WidgetRef ref,
+    String current, {
+    void Function(String)? onSave,
+    String? title,
+    String? description,
+  }) {
     final controller = TextEditingController(text: current);
     final colorScheme = Theme.of(context).colorScheme;
 
@@ -1035,14 +1058,14 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                       ),
                     ),
                     Text(
-                      context.l10n.filenameFormat,
+                      title ?? context.l10n.filenameFormat,
                       style: Theme.of(context).textTheme.headlineSmall
                           ?.copyWith(fontWeight: FontWeight.bold),
                       textAlign: TextAlign.center,
                     ),
                     const SizedBox(height: 8),
                     Text(
-                      context.l10n.downloadFilenameDescription,
+                      description ?? context.l10n.downloadFilenameDescription,
                       style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                         color: colorScheme.onSurfaceVariant,
                       ),
@@ -1149,9 +1172,12 @@ class _DownloadSettingsPageState extends ConsumerState<DownloadSettingsPage> {
                           flex: 2,
                           child: FilledButton(
                             onPressed: () {
-                              ref
-                                  .read(settingsProvider.notifier)
-                                  .setFilenameFormat(controller.text);
+                              final save =
+                                  onSave ??
+                                  ref
+                                      .read(settingsProvider.notifier)
+                                      .setFilenameFormat;
+                              save(controller.text);
                               Navigator.pop(context);
                             },
                             style: FilledButton.styleFrom(