fix: play synced items without a reachable server (#970)

lib/models/playback/playback_model.dart

@@ -154,6 +154,9 @@ final playbackModelHelper = Provider<PlaybackModelHelper>((ref) {
   return PlaybackModelHelper(ref: ref);
 });
 
+@visibleForTesting
+bool useLocalSyncedCopy({required bool isSynced, required bool serverReachable}) => isSynced && !serverReachable;
+
 class PlaybackModelHelper {
   const PlaybackModelHelper({required this.ref});
 
@@ -267,18 +270,45 @@ class PlaybackModelHelper {
 
       if (firstItemToPlay == null) return null;
 
-      final fullItemResponse = await api.usersUserIdItemsItemIdGet(itemId: firstItemToPlay.id);
+      final syncedItem = await ref.read(syncProvider.notifier).getSyncedItem(firstItemToPlay.id);
+      final firstItemIsSynced = syncedItem != null && syncedItem.status == TaskStatus.complete;
+      final isOffline = ref.read(connectivityStatusProvider.select((value) => value == ConnectionState.offline));
+
+      if (useLocalSyncedCopy(isSynced: firstItemIsSynced, serverReachable: !isOffline)) {
+        final offlineModel = await _createOfflinePlaybackModel(
+          firstItemToPlay,
+          item.streamModel,
+          syncedItem,
+          oldModel: oldModel,
+          queueSource: effectiveQueueSource,
+        );
+        if (offlineModel != null) return offlineModel;
+      }
+
+      Response<ItemBaseModel>? fullItemResponse;
+      try {
+        fullItemResponse =
+            await api.usersUserIdItemsItemIdGet(itemId: firstItemToPlay.id).timeout(const Duration(seconds: 5));
+      } catch (e) {
+        log("Error fetching item, falling back to offline: ${e.toString()}");
+      }
 
-      final fullItem = fullItemResponse.body;
+      final fullItem = fullItemResponse?.body;
 
       if (fullItem == null) {
+        if (firstItemIsSynced) {
+          final offlineModel = await _createOfflinePlaybackModel(
+            firstItemToPlay,
+            item.streamModel,
+            syncedItem,
+            oldModel: oldModel,
+            queueSource: effectiveQueueSource,
+          );
+          if (offlineModel != null) return offlineModel;
+        }
         return null;
       }
 
-      SyncedItem? syncedItem = await ref.read(syncProvider.notifier).getSyncedItem(fullItem.id);
-
-      final firstItemIsSynced = syncedItem != null && syncedItem.status == TaskStatus.complete;
-
       final actualStartPosition = startPosition ?? fullItem.userData.playBackPosition;
 
       final options = {
@@ -287,8 +317,6 @@ class PlaybackModelHelper {
         if (firstItemIsSynced) PlaybackType.offline,
       };
 
-      final isOffline = ref.read(connectivityStatusProvider.select((value) => value == ConnectionState.offline));
-
       if (firstItemToPlay is AudioModel && firstItemIsSynced) {
         final offlinePlayback = await _createOfflinePlaybackModel(
           fullItem,

test/models/playback/playback_model_test.dart

@@ -0,0 +1,23 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:fladder/models/playback/playback_model.dart';
+
+void main() {
+  group('useLocalSyncedCopy', () {
+    test('plays local copy when synced and server is unreachable', () {
+      expect(useLocalSyncedCopy(isSynced: true, serverReachable: false), isTrue);
+    });
+
+    test('uses server when synced and server is reachable', () {
+      expect(useLocalSyncedCopy(isSynced: true, serverReachable: true), isFalse);
+    });
+
+    test('does not force local when item is not synced, even if server unreachable', () {
+      expect(useLocalSyncedCopy(isSynced: false, serverReachable: false), isFalse);
+    });
+
+    test('uses server when not synced and server reachable', () {
+      expect(useLocalSyncedCopy(isSynced: false, serverReachable: true), isFalse);
+    });
+  });
+}