Run startup sync in background isolate

app/lib/app_init.dart

@@ -39,7 +39,10 @@ import 'package:visibility_detector/visibility_detector.dart';
 
 enum InitIsolateType {
   main,
-  service,
+
+  /// Isolates with Flutter engine, e.g., those spawned by flutter_isolate or
+  /// flutter_background_service
+  flutterIsolate,
 }
 
 Future<void> init(InitIsolateType isolateType) async {
@@ -200,7 +203,7 @@ Future<sql.SqliteDb> _createDb(InitIsolateType isolateType) async {
         return sql_isolate.createDb();
       }
 
-    case InitIsolateType.service:
+    case InitIsolateType.flutterIsolate:
       // service already runs in an isolate
       return sql.SqliteDb();
   }

app/lib/service.dart

@@ -70,7 +70,7 @@ class _Service {
     final service = FlutterBackgroundService();
     service.setForegroundMode(true);
 
-    await app_init.init(app_init.InitIsolateType.service);
+    await app_init.init(app_init.InitIsolateType.flutterIsolate);
     await _L10n().init();
 
     _log.info("[call] Service started");

app/lib/use_case/startup_sync.dart

@@ -0,0 +1,104 @@
+import 'dart:async';
+
+import 'package:event_bus/event_bus.dart';
+import 'package:flutter_isolate/flutter_isolate.dart';
+import 'package:kiwi/kiwi.dart';
+import 'package:logging/logging.dart';
+import 'package:nc_photos/account.dart';
+import 'package:nc_photos/app_init.dart' as app_init;
+import 'package:nc_photos/di_container.dart';
+import 'package:nc_photos/event/event.dart';
+import 'package:nc_photos/platform/k.dart' as platform_k;
+import 'package:nc_photos/type.dart';
+import 'package:nc_photos/use_case/sync_favorite.dart';
+
+/// Sync various properties with server during startup
+class StartupSync {
+  StartupSync(this._c)
+      : assert(require(_c)),
+        assert(SyncFavorite.require(_c));
+
+  static bool require(DiContainer c) => true;
+
+  /// Sync in a background isolate
+  static Future<SyncResult> runInIsolate(Account account) async {
+    if (platform_k.isWeb) {
+      // not supported on web
+      final c = KiwiContainer().resolve<DiContainer>();
+      return await StartupSync(c)(account);
+    } else {
+      // we can't use regular isolate here because self-signed cert support
+      // requires native plugins
+      final resultJson =
+          await flutterCompute(_isolateMain, _IsolateMessage(account).toJson());
+      final result = SyncResult.fromJson(resultJson);
+      // events fired in background isolate won't be noticed by the main isolate,
+      // so we fire them again here
+      _broadcastResult(account, result);
+      return result;
+    }
+  }
+
+  Future<SyncResult> call(Account account) async {
+    _log.info("[_run] Begin sync");
+    late final int syncFavoriteCount;
+    try {
+      syncFavoriteCount = await SyncFavorite(_c)(account);
+    } catch (e, stackTrace) {
+      _log.shout("[_run] Failed while SyncFavorite", e, stackTrace);
+      syncFavoriteCount = -1;
+    }
+    return SyncResult(syncFavoriteCount);
+  }
+
+  static void _broadcastResult(Account account, SyncResult result) {
+    final eventBus = KiwiContainer().resolve<EventBus>();
+    if (result.syncFavoriteCount > 0) {
+      eventBus.fire(FavoriteResyncedEvent(account));
+    }
+  }
+
+  final DiContainer _c;
+
+  static final _log = Logger("use_case.startup_sync.StartupSync");
+}
+
+class SyncResult {
+  const SyncResult(this.syncFavoriteCount);
+
+  factory SyncResult.fromJson(JsonObj json) => SyncResult(
+        json["syncFavoriteCount"],
+      );
+
+  JsonObj toJson() => {
+        "syncFavoriteCount": syncFavoriteCount,
+      };
+
+  final int syncFavoriteCount;
+}
+
+class _IsolateMessage {
+  const _IsolateMessage(this.account);
+
+  factory _IsolateMessage.fromJson(JsonObj json) => _IsolateMessage(
+        Account.fromJson(
+          json["account"].cast<String, dynamic>(),
+          upgraderV1: const AccountUpgraderV1(),
+        )!,
+      );
+
+  JsonObj toJson() => {
+        "account": account.toJson(),
+      };
+
+  final Account account;
+}
+
+Future<JsonObj> _isolateMain(JsonObj messageJson) async {
+  final message = _IsolateMessage.fromJson(messageJson);
+  await app_init.init(app_init.InitIsolateType.flutterIsolate);
+
+  final c = KiwiContainer().resolve<DiContainer>();
+  final result = await StartupSync(c)(message.account);
+  return result.toJson();
+}

app/lib/widget/home_photos.dart

@@ -21,7 +21,6 @@ import 'package:nc_photos/entity/album.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file_util.dart' as file_util;
 import 'package:nc_photos/event/event.dart';
-import 'package:nc_photos/exception.dart';
 import 'package:nc_photos/exception_util.dart' as exception_util;
 import 'package:nc_photos/k.dart' as k;
 import 'package:nc_photos/language_util.dart' as language_util;
@@ -35,7 +34,7 @@ import 'package:nc_photos/share_handler.dart';
 import 'package:nc_photos/snack_bar_manager.dart';
 import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/throttler.dart';
-import 'package:nc_photos/use_case/sync_favorite.dart';
+import 'package:nc_photos/use_case/startup_sync.dart';
 import 'package:nc_photos/widget/album_browser_util.dart' as album_browser_util;
 import 'package:nc_photos/widget/builder/photo_list_item_builder.dart';
 import 'package:nc_photos/widget/handler/add_selection_to_album_handler.dart';
@@ -381,7 +380,7 @@ class _HomePhotosState extends State<HomePhotos>
         state is ScanAccountDirBlocLoading) {
       _transformItems(state.files);
       if (state is ScanAccountDirBlocSuccess) {
-        _syncFavorite();
+        _startupSync();
         _tryStartMetadataTask();
       }
     } else if (state is ScanAccountDirBlocFailure) {
@@ -536,18 +535,10 @@ class _HomePhotosState extends State<HomePhotos>
     }
   }
 
-  Future<void> _syncFavorite() async {
+  Future<void> _startupSync() async {
     if (!_hasResyncedFavorites.value) {
-      final c = KiwiContainer().resolve<DiContainer>();
-      try {
-        await SyncFavorite(c)(widget.account);
-      } catch (e, stackTrace) {
-        if (e is! ApiException) {
-          _log.shout(
-              "[_syncFavorite] Failed while SyncFavorite", e, stackTrace);
-        }
-      }
       _hasResyncedFavorites.value = true;
+      StartupSync.runInIsolate(widget.account);
     }
   }
 

app/pubspec.lock

@@ -490,6 +490,15 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "3.3.0"
+  flutter_isolate:
+    dependency: "direct main"
+    description:
+      path: "."
+      ref: "2.0.2-nc-photos-1"
+      resolved-ref: "8d8516b169860caba762baed43a7888798c5b7d7"
+      url: "https://gitlab.com/nc-photos/flutter_isolate.git"
+    source: git
+    version: "2.0.2"
   flutter_keyboard_visibility:
     dependency: transitive
     description:

app/pubspec.yaml

@@ -57,6 +57,10 @@ dependencies:
       url: https://gitlab.com/nc-photos/flutter_background_service.git
       ref: v0.2.6-nc-photos-2
   flutter_bloc: ^8.0.0
+  flutter_isolate:
+    git:
+      url: https://gitlab.com/nc-photos/flutter_isolate.git
+      ref: 2.0.2-nc-photos-1
   flutter_map: ^1.1.1
   flutter_staggered_grid_view:
     git: