feat(backup): allow selecting categories and settings-only backups

lib/l10n/arb/app_en.arb

@@ -4044,6 +4044,14 @@
   "@backupContentsTitle": {
     "description": "Header above the list summarizing what the backup contains"
   },
+  "backupSettingsOnly": "Settings only",
+  "backupSelectHistory": "Download history",
+  "backupSelectCollections": "Library collections",
+  "backupSelectCollectionsDescription": "Liked tracks, wishlist, favorite artists, playlists and playlist covers.",
+  "backupSelectExtensions": "Extensions and their settings",
+  "backupSelectedExportDescription": "Save the selected categories to a backup file. Audio files are not included.",
+  "backupSelectAtLeastOne": "Select at least one category to create a backup.",
+  "backupSelectedRestoreMessage": "Only the categories listed below will be restored. Categories not included in this backup will stay unchanged. Restoring can replace existing data and cannot be undone.",
   "backupContentsSettings": "App settings",
   "@backupContentsSettings": {
     "description": "Backup contents row label for settings"

lib/l10n/arb/app_id.arb

@@ -5914,6 +5914,14 @@
   "libraryFilterTitle": "Filters",
   "cleanupOrphanedDownloadsResult": "Removed {count} orphaned entries from history",
   "extensionHooksAvailable": "{count} hook tersedia",
+  "backupSettingsOnly": "Pengaturan saja",
+  "backupSelectHistory": "Riwayat download",
+  "backupSelectCollections": "Koleksi library",
+  "backupSelectCollectionsDescription": "Lagu disukai, wishlist, artis favorit, playlist, dan sampul playlist.",
+  "backupSelectExtensions": "Ekstensi dan pengaturannya",
+  "backupSelectedExportDescription": "Simpan kategori yang dipilih ke file backup. File audio tidak disertakan.",
+  "backupSelectAtLeastOne": "Pilih minimal satu kategori untuk membuat backup.",
+  "backupSelectedRestoreMessage": "Hanya kategori di bawah yang akan dipulihkan. Kategori yang tidak disertakan dalam backup ini tidak akan berubah. Pemulihan dapat mengganti data yang ada dan tidak dapat dibatalkan.",
   "backupContentsSettings": "App settings",
   "trackLyricsEmbedded": "Lirik berhasil disematkan",
   "optionsUpdateChannelPreview": "Dapatkan rilis preview",

lib/screens/settings/backup_restore_page.dart

@@ -28,25 +28,43 @@ class _BackupRestorePageState extends ConsumerState<BackupRestorePage> {
   bool _isExporting = false;
   bool _isImporting = false;
   bool _includeSecrets = false;
+  bool _includeSettings = true;
+  bool _includeHistory = true;
+  bool _includeCollections = true;
+  bool _includeExtensions = true;
 
   bool get _isBusy => _isExporting || _isImporting;
+  bool get _hasSelection =>
+      _includeSettings ||
+      _includeHistory ||
+      _includeCollections ||
+      _includeExtensions;
 
   Future<void> _createBackup() async {
-    if (_isBusy) return;
+    if (_isBusy || !_hasSelection) return;
     setState(() => _isExporting = true);
     final l10n = context.l10n;
     final messenger = ScaffoldMessenger.of(context);
     try {
-      final settings = ref.read(settingsProvider).toJson();
-      final collectionsNotifier = ref.read(libraryCollectionsProvider.notifier);
-      final collections = await collectionsNotifier.exportCollections();
-      final covers = await collectionsNotifier.exportPlaylistCoverFiles();
-      final extensions = await ref
-          .read(extensionProvider.notifier)
-          .exportBackup(includeSecrets: _includeSecrets);
+      final settings = _includeSettings
+          ? ref.read(settingsProvider).toJson()
+          : null;
+      var collections = <String, dynamic>{};
+      var covers = <String, Map<String, String>>{};
+      if (_includeCollections) {
+        final notifier = ref.read(libraryCollectionsProvider.notifier);
+        collections = await notifier.exportCollections();
+        covers = await notifier.exportPlaylistCoverFiles();
+      }
+      final extensions = _includeExtensions
+          ? await ref
+                .read(extensionProvider.notifier)
+                .exportBackup(includeSecrets: _includeSecrets)
+          : <String, dynamic>{};
 
       final file = await BackupService.writeBackupArchive(
         settings: settings,
+        includeHistory: _includeHistory,
         loadHistoryPage: (limit, offset) =>
             HistoryDatabase.instance.getAll(limit: limit, offset: offset),
         collections: collections,
@@ -111,15 +129,19 @@ class _BackupRestorePageState extends ConsumerState<BackupRestorePage> {
             .read(settingsProvider.notifier)
             .restoreFromBackup(bundle.settings!);
       }
-      await ref
-          .read(downloadHistoryProvider.notifier)
-          .restoreFromBackupStream(bundle.streamHistory());
-      await ref
-          .read(libraryCollectionsProvider.notifier)
-          .restoreFromBackup(
-            bundle.collections,
-            coverImages: bundle.playlistCovers,
-          );
+      if (bundle.hasHistory) {
+        await ref
+            .read(downloadHistoryProvider.notifier)
+            .restoreFromBackupStream(bundle.streamHistory());
+      }
+      if (bundle.hasCollections) {
+        await ref
+            .read(libraryCollectionsProvider.notifier)
+            .restoreFromBackup(
+              bundle.collections,
+              coverImages: bundle.playlistCovers,
+            );
+      }
 
       ExtensionRestoreResult? extResult;
       if (bundle.hasExtensions) {
@@ -164,7 +186,7 @@ class _BackupRestorePageState extends ConsumerState<BackupRestorePage> {
             mainAxisSize: MainAxisSize.min,
             crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-              Text(l10n.backupRestoreConfirmMessage),
+              Text(l10n.backupSelectedRestoreMessage),
               const SizedBox(height: 16),
               Text(
                 l10n.backupContentsTitle,
@@ -178,22 +200,26 @@ class _BackupRestorePageState extends ConsumerState<BackupRestorePage> {
                   icon: Icons.settings_outlined,
                   label: l10n.backupContentsSettings,
                 ),
-              _ContentRow(
-                icon: Icons.history,
-                label: l10n.backupContentsHistory(bundle.historyCount),
-              ),
-              _ContentRow(
-                icon: Icons.favorite_outline,
-                label: l10n.backupContentsLiked(bundle.likedCount),
-              ),
-              _ContentRow(
-                icon: Icons.bookmark_outline,
-                label: l10n.backupContentsWishlist(bundle.wishlistCount),
-              ),
-              _ContentRow(
-                icon: Icons.queue_music_outlined,
-                label: l10n.backupContentsPlaylists(bundle.playlistCount),
-              ),
+              if (bundle.hasHistory)
+                _ContentRow(
+                  icon: Icons.history,
+                  label: l10n.backupContentsHistory(bundle.historyCount),
+                ),
+              if (bundle.hasCollections)
+                _ContentRow(
+                  icon: Icons.favorite_outline,
+                  label: l10n.backupContentsLiked(bundle.likedCount),
+                ),
+              if (bundle.hasCollections)
+                _ContentRow(
+                  icon: Icons.bookmark_outline,
+                  label: l10n.backupContentsWishlist(bundle.wishlistCount),
+                ),
+              if (bundle.hasCollections)
+                _ContentRow(
+                  icon: Icons.queue_music_outlined,
+                  label: l10n.backupContentsPlaylists(bundle.playlistCount),
+                ),
               if (bundle.favoriteArtistCount > 0)
                 _ContentRow(
                   icon: Icons.person_outline,
@@ -235,20 +261,71 @@ class _BackupRestorePageState extends ConsumerState<BackupRestorePage> {
           SliverToBoxAdapter(
             child: SettingsGroup(
               children: [
+                SettingsItem(
+                  icon: Icons.settings_outlined,
+                  title: l10n.backupSettingsOnly,
+                  onTap: _isBusy
+                      ? null
+                      : () => setState(() {
+                          _includeSettings = true;
+                          _includeHistory = false;
+                          _includeCollections = false;
+                          _includeExtensions = false;
+                          _includeSecrets = false;
+                        }),
+                ),
+                SettingsSwitchItem(
+                  icon: Icons.settings_outlined,
+                  title: l10n.backupContentsSettings,
+                  value: _includeSettings,
+                  onChanged: _isBusy
+                      ? null
+                      : (value) => setState(() => _includeSettings = value),
+                ),
+                SettingsSwitchItem(
+                  icon: Icons.history,
+                  title: l10n.backupSelectHistory,
+                  value: _includeHistory,
+                  onChanged: _isBusy
+                      ? null
+                      : (value) => setState(() => _includeHistory = value),
+                ),
+                SettingsSwitchItem(
+                  icon: Icons.library_music_outlined,
+                  title: l10n.backupSelectCollections,
+                  subtitle: l10n.backupSelectCollectionsDescription,
+                  value: _includeCollections,
+                  onChanged: _isBusy
+                      ? null
+                      : (value) => setState(() => _includeCollections = value),
+                ),
+                SettingsSwitchItem(
+                  icon: Icons.extension_outlined,
+                  title: l10n.backupSelectExtensions,
+                  value: _includeExtensions,
+                  onChanged: _isBusy
+                      ? null
+                      : (value) => setState(() {
+                          _includeExtensions = value;
+                          if (!value) _includeSecrets = false;
+                        }),
+                ),
                 SettingsSwitchItem(
                   icon: Icons.vpn_key_outlined,
                   title: l10n.backupIncludeSecrets,
                   subtitle: l10n.backupIncludeSecretsDescription,
                   value: _includeSecrets,
-                  onChanged: _isBusy
+                  onChanged: _isBusy || !_includeExtensions
                       ? null
                       : (value) => setState(() => _includeSecrets = value),
                 ),
                 SettingsItem(
                   icon: Icons.ios_share,
                   title: l10n.backupExportButton,
-                  subtitle: l10n.backupExportSectionDescription,
-                  onTap: _isBusy ? null : _createBackup,
+                  subtitle: _hasSelection
+                      ? l10n.backupSelectedExportDescription
+                      : l10n.backupSelectAtLeastOne,
+                  onTap: _isBusy || !_hasSelection ? null : _createBackup,
                   trailing: _isExporting
                       ? const SizedBox(
                           width: 20,

lib/services/backup_service.dart

@@ -10,7 +10,7 @@ import 'package:spotiflac_android/utils/logger.dart';
 typedef BackupHistoryPageLoader =
     Future<List<Map<String, dynamic>>> Function(int limit, int offset);
 
-/// Parsed contents of a backup file. Version 2 keeps large history and cover
+/// Parsed contents of a backup file. ZIP backups keep large history and cover
 /// payloads on disk until restore consumes them.
 class BackupBundle {
   final int formatVersion;
@@ -21,6 +21,7 @@ class BackupBundle {
   final Map<String, dynamic> collections;
   final Map<String, dynamic> playlistCovers;
   final Map<String, dynamic> extensions;
+  final bool hasHistory;
   final String? _historyNdjsonPath;
   final int? _historyCount;
   final String? _temporaryDirectoryPath;
@@ -34,6 +35,7 @@ class BackupBundle {
     required this.collections,
     required this.playlistCovers,
     required this.extensions,
+    this.hasHistory = true,
     String? historyNdjsonPath,
     int? historyCount,
     String? temporaryDirectoryPath,
@@ -42,6 +44,7 @@ class BackupBundle {
        _temporaryDirectoryPath = temporaryDirectoryPath;
 
   bool get hasSettings => settings != null && settings!.isNotEmpty;
+  bool get hasCollections => collections.isNotEmpty;
   int get historyCount => _historyCount ?? history.length;
 
   Stream<Map<String, dynamic>> streamHistory() async* {
@@ -97,7 +100,9 @@ class BackupService {
   static final _log = AppLogger('BackupService');
 
   static const String magic = 'spotiflac-backup';
-  static const int formatVersion = 2;
+  // V3 permits omitted categories. Older readers reject it instead of treating
+  // an omitted history as an empty history and clearing existing downloads.
+  static const int formatVersion = 3;
   static const String fileExtension = 'sflb';
   static const int _historyPageSize = 500;
   static const int _maxMetadataBytes = 8 << 20;
@@ -141,6 +146,7 @@ class BackupService {
     required Map<String, dynamic> extensions,
     Directory? outputDirectory,
     Directory? temporaryDirectory,
+    bool includeHistory = true,
   }) async {
     final output = await _newBackupFile(outputDirectory);
     final tempRoot = temporaryDirectory ?? await getTemporaryDirectory();
@@ -160,7 +166,7 @@ class BackupService {
       var offset = 0;
       final historySink = historyFile.openWrite();
       try {
-        while (true) {
+        while (includeHistory) {
           final page = await loadHistoryPage(_historyPageSize, offset);
           for (final item in page) {
             historySink.writeln(jsonEncode(item));
@@ -194,10 +200,10 @@ class BackupService {
         'created_at': DateTime.now().toIso8601String(),
         'history_count': historyCount,
         'data': {
-          'settings': settings,
-          'collections': collections,
-          'playlist_covers': coverManifest,
-          'extensions': extensions,
+          'settings': ?settings,
+          if (collections.isNotEmpty) 'collections': collections,
+          if (coverManifest.isNotEmpty) 'playlist_covers': coverManifest,
+          if (extensions.isNotEmpty) 'extensions': extensions,
         },
       };
       await metadataFile.writeAsString(jsonEncode(metadata), flush: true);
@@ -205,7 +211,9 @@ class BackupService {
       if (await partFile.exists()) await partFile.delete();
       encoder = ZipFileEncoder()..create(partFile.path);
       await encoder.addFile(metadataFile, 'metadata.json');
-      await encoder.addFile(historyFile, 'history.ndjson');
+      if (includeHistory) {
+        await encoder.addFile(historyFile, 'history.ndjson');
+      }
       for (final entry in coverManifest.entries) {
         final sourcePath = playlistCoverFiles[entry.key]?['path'];
         if (sourcePath == null) continue;
@@ -289,14 +297,18 @@ class BackupService {
       final historyEntry = archive.find('history.ndjson');
       if (metadataEntry == null ||
           metadataEntry.size > _maxMetadataBytes ||
-          historyEntry == null ||
-          historyEntry.size > _maxHistoryBytes) {
+          (historyEntry != null && historyEntry.size > _maxHistoryBytes)) {
         return null;
       }
       final rootRaw = jsonDecode(utf8.decode(metadataEntry.content));
       if (rootRaw is! Map) return null;
       final root = Map<String, dynamic>.from(rootRaw);
-      if (root['magic'] != magic || root['format_version'] != formatVersion) {
+      final version = root['format_version'];
+      if (root['magic'] != magic ||
+          (version != 2 && version != formatVersion)) {
+        return null;
+      }
+      if (version == 2 && historyEntry == null) {
         return null;
       }
       final dataRaw = root['data'];
@@ -310,10 +322,13 @@ class BackupService {
           'spotiflac_restore_${DateTime.now().microsecondsSinceEpoch}',
         ),
       ).create(recursive: true);
-      final historyPath = p.join(extractionDir.path, 'history.ndjson');
-      final historyOutput = OutputFileStream(historyPath);
-      historyEntry.writeContent(historyOutput);
-      historyOutput.closeSync();
+      String? historyPath;
+      if (historyEntry != null) {
+        historyPath = p.join(extractionDir.path, 'history.ndjson');
+        final historyOutput = OutputFileStream(historyPath);
+        historyEntry.writeContent(historyOutput);
+        historyOutput.closeSync();
+      }
 
       final restoredCovers = <String, dynamic>{};
       final coverManifest = data['playlist_covers'];
@@ -350,11 +365,12 @@ class BackupService {
       }
 
       return BackupBundle(
-        formatVersion: formatVersion,
+        formatVersion: version as int,
         appVersion: root['app_version'] as String? ?? '',
         createdAt: DateTime.tryParse(root['created_at'] as String? ?? ''),
         settings: _mapOrNull(data['settings']),
         history: const [],
+        hasHistory: historyEntry != null,
         historyNdjsonPath: historyPath,
         historyCount: (root['history_count'] as num?)?.toInt() ?? 0,
         collections: _mapOrEmpty(data['collections']),
@@ -399,6 +415,7 @@ class BackupService {
       createdAt: DateTime.tryParse(root['created_at'] as String? ?? ''),
       settings: _mapOrNull(data['settings']),
       history: history,
+      hasHistory: data['history'] is List,
       collections: _mapOrEmpty(data['collections']),
       playlistCovers: _mapOrEmpty(data['playlist_covers']),
       extensions: _mapOrEmpty(data['extensions']),