feat: migrate downloads to background_downloader

close #454

android/app/src/main/AndroidManifest.xml

@@ -17,6 +17,10 @@
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK"/>
 
+    <!-- Background download notifications and foreground service -->
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC"/>
+
     <!-- Explicitly remove media permissions that media_kit may add -->
     <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" tools:node="remove" />
     <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" tools:node="remove" />

ios/Podfile.lock

@@ -1,4 +1,6 @@
 PODS:
+  - background_downloader (0.0.1):
+    - Flutter
   - connectivity_plus (0.0.1):
     - Flutter
   - device_info_plus (0.0.1):
@@ -105,6 +107,7 @@ PODS:
     - Flutter
 
 DEPENDENCIES:
+  - background_downloader (from `.symlinks/plugins/background_downloader/ios`)
   - connectivity_plus (from `.symlinks/plugins/connectivity_plus/ios`)
   - device_info_plus (from `.symlinks/plugins/device_info_plus/ios`)
   - file_picker (from `.symlinks/plugins/file_picker/ios`)
@@ -138,6 +141,8 @@ SPEC REPOS:
     - sqlite3
 
 EXTERNAL SOURCES:
+  background_downloader:
+    :path: ".symlinks/plugins/background_downloader/ios"
   connectivity_plus:
     :path: ".symlinks/plugins/connectivity_plus/ios"
   device_info_plus:
@@ -172,6 +177,7 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/workmanager_apple/ios"
 
 SPEC CHECKSUMS:
+  background_downloader: 50e91d979067b82081aba359d7d916b3ba5fadad
   connectivity_plus: cb623214f4e1f6ef8fe7403d580fdad517d2f7dd
   device_info_plus: 21fcca2080fbcd348be798aa36c3e5ed849eefbe
   file_picker: 8fc6fe5e42585a217d44d22f79ec046cb8d81140

ios/Runner/Info.plist

@@ -49,6 +49,11 @@
 	<string>LaunchScreen</string>
 	<key>UIMainStoryboardFile</key>
 	<string>Main</string>
+	<key>UIBackgroundModes</key>
+	<array>
+		<string>fetch</string>
+		<string>processing</string>
+	</array>
 	<key>UISupportedInterfaceOrientations</key>
 	<array>
 		<string>UIInterfaceOrientationPortrait</string>

lib/database/app_database.dart

@@ -16,7 +16,7 @@ class AppDatabase extends _$AppDatabase {
   AppDatabase() : super(_openConnection());
 
   @override
-  int get schemaVersion => 7; // Added OfflineWatchProgress table
+  int get schemaVersion => 8; // Added bgTaskId column to DownloadedMedia
 
   @override
   MigrationStrategy get migration {
@@ -25,11 +25,14 @@ class AppDatabase extends _$AppDatabase {
         await m.createAll();
       },
       onUpgrade: (Migrator m, int from, int to) async {
-        // Additive migration for schema version 7
         if (from < 7) {
           appLogger.i('Adding OfflineWatchProgress table (v7 migration)');
           await m.createTable(offlineWatchProgress);
         }
+        if (from < 8) {
+          appLogger.i('Adding bgTaskId column to DownloadedMedia (v8 migration)');
+          await m.addColumn(downloadedMedia, downloadedMedia.bgTaskId);
+        }
       },
     );
   }

lib/database/tables.dart

@@ -47,6 +47,7 @@ class DownloadedMedia extends Table {
   IntColumn get downloadedAt => integer().nullable()();
   TextColumn get errorMessage => text().nullable()();
   IntColumn get retryCount => integer().withDefault(const Constant(0))();
+  TextColumn get bgTaskId => text().nullable()();
 }
 
 /// Queue for offline watch progress and manual watch actions.

lib/widgets/download_tree_view.dart

@@ -654,8 +654,8 @@ class _DownloadTreeItemState extends State<_DownloadTreeItem> {
                 ),
               ],
 
-              // Progress bar
-              if (widget.node.status == DownloadStatus.downloading || widget.node.status == DownloadStatus.queued) ...[
+              // Progress bar for active downloads
+              if (widget.node.status == DownloadStatus.downloading) ...[
                 const SizedBox(height: 8),
                 LinearProgressIndicator(
                   value: widget.node.progress,
@@ -671,6 +671,17 @@ class _DownloadTreeItemState extends State<_DownloadTreeItem> {
                   ),
                 ],
               ],
+
+              // Queued label
+              if (widget.node.status == DownloadStatus.queued) ...[
+                const SizedBox(height: 4),
+                Text(
+                  t.downloads.downloadQueued,
+                  style: theme.textTheme.bodySmall?.copyWith(
+                    color: theme.colorScheme.onSurface.withValues(alpha: 0.5),
+                  ),
+                ),
+              ],
             ],
           ),
         ),

pubspec.lock

@@ -65,6 +65,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.13.0"
+  background_downloader:
+    dependency: "direct main"
+    description:
+      name: background_downloader
+      sha256: "2ea5322fe836c0aaf96aefd29ef1936771c71927f687cf18168dcc119666a45f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "9.5.2"
   boolean_selector:
     dependency: transitive
     description:

pubspec.yaml

@@ -53,6 +53,7 @@ dependencies:
   flutter_svg: ^2.2.3
   mobile_scanner: ^6.0.2
   android_intent_plus: ^5.0.2
+  background_downloader: ^9.5.2
 
 dev_dependencies:
   flutter_test: