refactor: deduplicate logic

lib/providers/offline_watch_provider.dart

@@ -106,6 +106,22 @@ class OfflineWatchProvider extends ChangeNotifier {
     return episodes;
   }
 
+  /// Batch resolve watch statuses for a list of episodes.
+  ///
+  /// Returns a map of globalKey -> isWatched for each episode.
+  Future<Map<String, bool>> _resolveEpisodeWatchStatuses(List<PlexMetadata> episodes) async {
+    if (episodes.isEmpty) return {};
+
+    final globalKeys = episodes.map((e) => e.globalKey).toSet();
+    final localStatuses = await _syncService.getLocalWatchStatusesBatched(globalKeys);
+
+    return {
+      for (final episode in episodes)
+        episode.globalKey:
+            localStatuses[episode.globalKey] ?? _downloadProvider.getMetadata(episode.globalKey)?.isWatched ?? false,
+    };
+  }
+
   /// Find the next unwatched downloaded episode for a show.
   ///
   /// This is the "offline OnDeck" calculation - finds the first
@@ -118,15 +134,11 @@ class OfflineWatchProvider extends ChangeNotifier {
     final episodes = _getSortedEpisodes(showRatingKey);
     if (episodes.isEmpty) return null;
 
-    // Batch fetch all watch statuses in a single query
+    final watchStatuses = await _resolveEpisodeWatchStatuses(episodes);
-    final globalKeys = episodes.map((e) => e.globalKey).toSet();
-    final localStatuses = await _syncService.getLocalWatchStatusesBatched(globalKeys);
 
     // Find first unwatched episode
     for (final episode in episodes) {
-      final localStatus = localStatuses[episode.globalKey];
+      if (!watchStatuses[episode.globalKey]!) {
-      final watched = localStatus ?? _downloadProvider.getMetadata(episode.globalKey)?.isWatched ?? false;
-      if (!watched) {
         return episode;
       }
     }
@@ -176,21 +188,11 @@ class OfflineWatchProvider extends ChangeNotifier {
   /// Uses batched database query for efficiency.
   Future<List<(PlexMetadata episode, bool isWatched)>> getEpisodesWithWatchStatus(String showRatingKey) async {
     final episodes = _downloadProvider.getDownloadedEpisodesForShow(showRatingKey);
-
     if (episodes.isEmpty) return [];
 
-    // Batch fetch all watch statuses in a single query
+    final watchStatuses = await _resolveEpisodeWatchStatuses(episodes);
-    final globalKeys = episodes.map((e) => e.globalKey).toSet();
-    final localStatuses = await _syncService.getLocalWatchStatusesBatched(globalKeys);
 
-    final results = <(PlexMetadata, bool)>[];
+    return [for (final episode in episodes) (episode, watchStatuses[episode.globalKey]!)];
-    for (final episode in episodes) {
-      final localStatus = localStatuses[episode.globalKey];
-      final watched = localStatus ?? _downloadProvider.getMetadata(episode.globalKey)?.isWatched ?? false;
-      results.add((episode, watched));
-    }
-
-    return results;
   }
 
   /// Trigger a manual sync of pending items.

lib/screens/settings/mpv_config_screen.dart

@@ -129,20 +129,27 @@ class _MpvConfigScreenState extends State<MpvConfigScreen> {
     valueController.dispose();
   }
 
-  Future<void> _showDeleteEntryDialog(int index) async {
+  Future<bool> _showConfirmDeleteDialog({required String title, required String content}) async {
     final result = await showDialog<bool>(
       context: context,
       builder: (context) => AlertDialog(
-        title: Text(t.mpvConfig.deleteProperty),
+        title: Text(title),
-        content: Text(t.mpvConfig.confirmDeleteProperty),
+        content: Text(content),
         actions: [
           TextButton(onPressed: () => Navigator.pop(context, false), child: Text(t.common.cancel)),
           TextButton(onPressed: () => Navigator.pop(context, true), child: Text(t.common.delete)),
         ],
       ),
     );
+    return result == true;
+  }
 
-    if (result == true) {
+  Future<void> _showDeleteEntryDialog(int index) async {
+    final confirmed = await _showConfirmDeleteDialog(
+      title: t.mpvConfig.deleteProperty,
+      content: t.mpvConfig.confirmDeleteProperty,
+    );
+    if (confirmed) {
       _deleteEntry(index);
     }
   }
@@ -201,19 +208,12 @@ class _MpvConfigScreenState extends State<MpvConfigScreen> {
   }
 
   Future<void> _deletePreset(MpvPreset preset) async {
-    final result = await showDialog<bool>(
+    final confirmed = await _showConfirmDeleteDialog(
-      context: context,
+      title: t.mpvConfig.deletePreset,
-      builder: (context) => AlertDialog(
+      content: t.mpvConfig.confirmDeletePreset,
-        title: Text(t.mpvConfig.deletePreset),
-        content: Text(t.mpvConfig.confirmDeletePreset),
-        actions: [
-          TextButton(onPressed: () => Navigator.pop(context, false), child: Text(t.common.cancel)),
-          TextButton(onPressed: () => Navigator.pop(context, true), child: Text(t.common.delete)),
-        ],
-      ),
     );
 
-    if (result == true) {
+    if (confirmed) {
       await _settingsService.deleteMpvPreset(preset.name);
       setState(() {
         _presets = _settingsService.getMpvPresets();

lib/services/data_aggregation_service.dart

@@ -247,15 +247,11 @@ class DataAggregationService {
 
   // Private helper methods
 
-  /// Higher-order helper for per-server fan-out operations
+  /// Base helper for per-server fan-out operations
   ///
-  /// Iterates over all online clients, executes the operation for each server,
+  /// Returns raw results as (serverId, result) tuples.
-  /// handles errors, updates server status, and aggregates results.
+  /// Used by [_perServer] and [_perServerGrouped] for different aggregation strategies.
-  ///
+  Future<List<(String serverId, List<T> result)>> _perServerRaw<T>({
-  /// Type parameter `T` is the item type returned by the operation
-  /// [operationName] is used for logging (e.g., "fetching libraries")
-  /// [operation] is the async function to run per server, returning `List<T>`
-  Future<List<T>> _perServer<T>({
     required String operationName,
     required Future<List<T>> Function(String serverId, PlexClient client, PlexServer? server) operation,
   }) async {
@@ -268,61 +264,6 @@ class DataAggregationService {
 
     appLogger.d('$operationName from ${clients.length} servers');
 
-    final allResults = <T>[];
-
-    // Execute operation on all servers in parallel
-    final Iterable<Future<List<T>>> futures = clients.entries.map((entry) async {
-      final serverId = entry.key;
-      final client = entry.value;
-      final server = _serverManager.getServer(serverId);
-      final sw = Stopwatch()..start();
-
-      try {
-        final result = await operation(serverId, client, server);
-        appLogger.d(
-          '$operationName for server $serverId completed in ${sw.elapsedMilliseconds}ms with ${result.length} items',
-        );
-        return result;
-      } catch (e, stackTrace) {
-        appLogger.e('Failed $operationName from server $serverId', error: e, stackTrace: stackTrace);
-        _serverManager.updateServerStatus(serverId, false);
-        appLogger.d('$operationName for server $serverId failed after ${sw.elapsedMilliseconds}ms');
-        return <T>[];
-      }
-    });
-
-    final List<List<T>> results = await Future.wait<List<T>>(futures);
-
-    // Flatten results
-    for (final items in results) {
-      allResults.addAll(items);
-    }
-
-    return allResults;
-  }
-
-  /// Higher-order helper for per-server fan-out operations that groups results by server
-  ///
-  /// Similar to [_perServer] but returns a Map with results grouped by serverId
-  /// instead of flattening into a single list.
-  ///
-  /// Type parameter `T` is the item type returned by the operation
-  /// [operationName] is used for logging (e.g., "fetching libraries")
-  /// [operation] is the async function to run per server, returning `List<T>`
-  Future<Map<String, List<T>>> _perServerGrouped<T>({
-    required String operationName,
-    required Future<List<T>> Function(String serverId, PlexClient client, PlexServer? server) operation,
-  }) async {
-    final clients = _serverManager.onlineClients;
-
-    if (clients.isEmpty) {
-      appLogger.w('No online servers available for $operationName');
-      return {};
-    }
-
-    appLogger.d('$operationName from ${clients.length} servers');
-
-    // Execute operation on all servers in parallel
     final futures = clients.entries.map((entry) async {
       final serverId = entry.key;
       final client = entry.value;
@@ -334,17 +275,38 @@ class DataAggregationService {
         appLogger.d(
           '$operationName for server $serverId completed in ${sw.elapsedMilliseconds}ms with ${result.length} items',
         );
-        return MapEntry(serverId, result);
+        return (serverId, result);
       } catch (e, stackTrace) {
         appLogger.e('Failed $operationName from server $serverId', error: e, stackTrace: stackTrace);
         _serverManager.updateServerStatus(serverId, false);
         appLogger.d('$operationName for server $serverId failed after ${sw.elapsedMilliseconds}ms');
-        return MapEntry(serverId, <T>[]);
+        return (serverId, <T>[]);
       }
     });
 
-    final results = await Future.wait(futures);
+    return await Future.wait(futures);
+  }
 
-    return Map.fromEntries(results);
+  /// Higher-order helper for per-server fan-out operations
+  ///
+  /// Iterates over all online clients, executes the operation for each server,
+  /// handles errors, updates server status, and flattens results into a single list.
+  Future<List<T>> _perServer<T>({
+    required String operationName,
+    required Future<List<T>> Function(String serverId, PlexClient client, PlexServer? server) operation,
+  }) async {
+    final results = await _perServerRaw(operationName: operationName, operation: operation);
+    return [for (final (_, items) in results) ...items];
+  }
+
+  /// Higher-order helper for per-server fan-out operations that groups results by server
+  ///
+  /// Similar to [_perServer] but returns a Map with results grouped by serverId.
+  Future<Map<String, List<T>>> _perServerGrouped<T>({
+    required String operationName,
+    required Future<List<T>> Function(String serverId, PlexClient client, PlexServer? server) operation,
+  }) async {
+    final results = await _perServerRaw(operationName: operationName, operation: operation);
+    return {for (final (id, items) in results) id: items};
   }
 }

lib/services/track_selection_service.dart

@@ -32,12 +32,7 @@ class TrackSelectionService {
   final PlexMetadata metadata;
   final PlexMediaInfo? plexMediaInfo;
 
-  TrackSelectionService({
+  TrackSelectionService({required this.player, this.profileSettings, required this.metadata, this.plexMediaInfo});
-    required this.player,
-    this.profileSettings,
-    required this.metadata,
-    this.plexMediaInfo,
-  });
 
   /// Build list of preferred languages from a user profile
   List<String> _buildPreferredLanguages(PlexUserProfile profile, {required bool isAudio}) {
@@ -324,7 +319,10 @@ class TrackSelectionService {
   /// Priority 3: Per-media language preference
   /// Priority 4: User profile preferences
   /// Priority 5: Default or first track
-  TrackSelectionResult<AudioTrack>? selectAudioTrack(List<AudioTrack> availableTracks, AudioTrack? preferredAudioTrack) {
+  TrackSelectionResult<AudioTrack>? selectAudioTrack(
+    List<AudioTrack> availableTracks,
+    AudioTrack? preferredAudioTrack,
+  ) {
     if (availableTracks.isEmpty) return null;
 
     AudioTrack? trackToSelect;

lib/watch_together/providers/watch_together_provider.dart

@@ -76,6 +76,14 @@ class WatchTogetherProvider with ChangeNotifier {
     _displayName = name;
   }
 
+  /// Wire up sync manager's state change callback to update provider state
+  void _wireSyncStateChanges() {
+    _syncManager!.onSyncStateChanged = (isSyncing) {
+      _isSyncing = isSyncing;
+      notifyListeners();
+    };
+  }
+
   /// Create a new watch together session as host
   Future<String> createSession({
     required ControlMode controlMode,
@@ -113,10 +121,7 @@ class WatchTogetherProvider with ChangeNotifier {
         displayName: _displayName,
       );
 
-      _syncManager!.onSyncStateChanged = (isSyncing) {
+      _wireSyncStateChanges();
-        _isSyncing = isSyncing;
-        notifyListeners();
-      };
 
       notifyListeners();
       appLogger.d('WatchTogether: Session created: $sessionId');
@@ -164,10 +169,7 @@ class WatchTogetherProvider with ChangeNotifier {
         notifyListeners();
       };
 
-      _syncManager!.onSyncStateChanged = (isSyncing) {
+      _wireSyncStateChanges();
-        _isSyncing = isSyncing;
-        notifyListeners();
-      };
 
       // Add self to participants
       _participants.add(Participant(peerId: _peerService!.myPeerId!, displayName: _displayName, isHost: false));

lib/watch_together/services/watch_together_peer_service.dart

@@ -83,6 +83,31 @@ class WatchTogetherPeerService {
     return const Uuid().v4().substring(0, 8).toUpperCase();
   }
 
+  /// Attach common peer event listeners for disconnected/close/error events
+  void _attachCommonPeerListeners({
+    required Completer completer,
+    required PeerErrorType errorType,
+    required String errorMessage,
+  }) {
+    _peer!.on('disconnected').listen((_) {
+      appLogger.w('WatchTogether: Peer disconnected from server');
+      _handleDisconnectedFromServer();
+    });
+
+    _peer!.on('close').listen((_) {
+      appLogger.d('WatchTogether: Peer closed');
+      _connectionStateController.add(false);
+    });
+
+    _peer!.on('error').listen((error) {
+      appLogger.e('WatchTogether: Peer error', error: error);
+      _errorController.add(PeerError(type: errorType, message: '$errorMessage: $error', originalError: error));
+      if (!completer.isCompleted) {
+        completer.completeError(error);
+      }
+    });
+  }
+
   /// Create a new session as host
   ///
   /// Returns the session ID that others can use to join
@@ -115,25 +140,11 @@ class WatchTogetherPeerService {
         _handleNewConnection(dataConn);
       });
 
-      _peer!.on('error').listen((error) {
+      _attachCommonPeerListeners(
-        appLogger.e('WatchTogether: Peer error', error: error);
+        completer: completer,
-        _errorController.add(
+        errorType: PeerErrorType.serverError,
-          PeerError(type: PeerErrorType.serverError, message: error.toString(), originalError: error),
+        errorMessage: 'Server error',
-        );
+      );
-        if (!completer.isCompleted) {
-          completer.completeError(error);
-        }
-      });
-
-      _peer!.on('disconnected').listen((_) {
-        appLogger.w('WatchTogether: Peer disconnected from server');
-        _handleDisconnectedFromServer();
-      });
-
-      _peer!.on('close').listen((_) {
-        appLogger.d('WatchTogether: Peer closed');
-        _connectionStateController.add(false);
-      });
     } catch (e) {
       appLogger.e('WatchTogether: Failed to create peer', error: e);
       if (!completer.isCompleted) {
@@ -178,29 +189,11 @@ class WatchTogetherPeerService {
         _handleNewConnection(conn, isOutgoing: true, completer: completer);
       });
 
-      _peer!.on('error').listen((error) {
+      _attachCommonPeerListeners(
-        appLogger.e('WatchTogether: Peer error', error: error);
+        completer: completer,
-        _errorController.add(
+        errorType: PeerErrorType.connectionFailed,
-          PeerError(
+        errorMessage: 'Failed to connect to session',
-            type: PeerErrorType.connectionFailed,
+      );
-            message: 'Failed to connect to session: $error',
-            originalError: error,
-          ),
-        );
-        if (!completer.isCompleted) {
-          completer.completeError(error);
-        }
-      });
-
-      _peer!.on('disconnected').listen((_) {
-        appLogger.w('WatchTogether: Peer disconnected from server');
-        _handleDisconnectedFromServer();
-      });
-
-      _peer!.on('close').listen((_) {
-        appLogger.d('WatchTogether: Peer closed');
-        _connectionStateController.add(false);
-      });
     } catch (e) {
       appLogger.e('WatchTogether: Failed to create peer for joining', error: e);
       if (!completer.isCompleted) {

lib/widgets/download_tree_view.dart

@@ -241,19 +241,9 @@ class _DownloadTreeViewState extends State<DownloadTreeView> {
       );
     }
 
-    // Sort shows by status and title
+    // Sort shows and movies by status and title
-    shows.sort((a, b) {
+    _sortNodesByStatusAndTitle(shows);
-      final statusCompare = _compareByStatus(a.status, b.status);
+    _sortNodesByStatusAndTitle(movies);
-      if (statusCompare != 0) return statusCompare;
-      return a.title.compareTo(b.title);
-    });
-
-    // Sort movies by status and title
-    movies.sort((a, b) {
-      final statusCompare = _compareByStatus(a.status, b.status);
-      if (statusCompare != 0) return statusCompare;
-      return a.title.compareTo(b.title);
-    });
 
     // Combine movies and shows
     return [...movies, ...shows];
@@ -292,6 +282,15 @@ class _DownloadTreeViewState extends State<DownloadTreeView> {
     return (statusOrder[a] ?? 99).compareTo(statusOrder[b] ?? 99);
   }
 
+  /// Sort nodes by status (downloading first) then by title
+  void _sortNodesByStatusAndTitle(List<DownloadTreeNode> nodes) {
+    nodes.sort((a, b) {
+      final statusCompare = _compareByStatus(a.status, b.status);
+      if (statusCompare != 0) return statusCompare;
+      return a.title.compareTo(b.title);
+    });
+  }
+
   /// Flatten the tree into a list of visible nodes with their depths
   List<_FlatNode> _flattenTree(List<DownloadTreeNode> nodes, [int depth = 0]) {
     final List<_FlatNode> result = [];

lib/widgets/horizontal_scroll_with_arrows.dart

@@ -61,25 +61,16 @@ class _HorizontalScrollWithArrowsState extends State<HorizontalScrollWithArrows>
     });
   }
 
-  void _scrollLeft() {
+  void _animateScroll(double direction) {
     final position = _scrollController.position;
-    final targetScroll = (position.pixels - (position.viewportDimension * widget.scrollAmount)).clamp(
+    final delta = direction * position.viewportDimension * widget.scrollAmount;
-      0.0,
+    final targetScroll = (position.pixels + delta).clamp(0.0, position.maxScrollExtent);
-      position.maxScrollExtent,
-    );
-
     _scrollController.animateTo(targetScroll, duration: tokens(context).slow, curve: Curves.easeInOut);
   }
 
-  void _scrollRight() {
+  void _scrollLeft() => _animateScroll(-1);
-    final position = _scrollController.position;
-    final targetScroll = (position.pixels + (position.viewportDimension * widget.scrollAmount)).clamp(
-      0.0,
-      position.maxScrollExtent,
-    );
 
-    _scrollController.animateTo(targetScroll, duration: tokens(context).slow, curve: Curves.easeInOut);
+  void _scrollRight() => _animateScroll(1);
-  }
 
   Widget _buildArrowButton({
     required double position,