support background execution

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 0.0.98
 
 - New: Groups can now collect flames as well
+- New: Background execution to pre-load messages 
 - New: Adds a link if the image contains a QR code
 - Improve: Video compression with progress updates
 - Improve: Show message "Flames restored"

android/app/src/main/AndroidManifest.xml

@@ -1,7 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools">
     <application
         android:label="twonly"
-        android:name="${applicationName}"
+        android:name=".MyApplication"
         android:allowBackup="false"
         android:fullBackupContent="false"
         android:icon="@mipmap/ic_launcher">

android/app/src/main/kotlin/eu/twonly/MyApplication.kt

@@ -0,0 +1,13 @@
+package eu.twonly
+
+import io.flutter.app.FlutterApplication
+import dev.fluttercommunity.workmanager.WorkmanagerDebug
+import dev.fluttercommunity.workmanager.LoggingDebugHandler
+
+class MyApplication : FlutterApplication() {
+    override fun onCreate() {
+        super.onCreate()
+        // This enables the internal plugin logging to Logcat
+        WorkmanagerDebug.setCurrent(LoggingDebugHandler())
+    }
+}

ios/Runner/AppDelegate.swift

@@ -4,6 +4,7 @@ import Foundation
 import UIKit
 import UserNotifications
 import flutter_sharing_intent
+import workmanager_apple
 
 @main
 @objc class AppDelegate: FlutterAppDelegate, FlutterImplicitEngineDelegate {
@@ -16,6 +17,17 @@ import flutter_sharing_intent
     if let registrar = self.registrar(forPlugin: "VideoCompressionChannel") {
       VideoCompressionChannel.register(with: registrar.messenger())
     }
+
+    WorkmanagerDebug.setCurrent(LoggingDebugHandler())
+
+    WorkmanagerPlugin.registerPeriodicTask(
+      withIdentifier: "eu.twonly.periodic_task",
+      frequency: NSNumber(value: 20 * 60)
+    )
+
+    WorkmanagerPlugin.registerBGProcessingTask(
+      withIdentifier: "eu.twonly.processing_task"
+    )
     
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }

ios/Runner/Info.plist

@@ -2,27 +2,8 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
-	<key>UIApplicationSceneManifest</key>
-	<dict>
-		<key>UIApplicationSupportsMultipleScenes</key>
-		<false/>
-		<key>UISceneConfigurations</key>
-		<dict>
-			<key>UIWindowSceneSessionRoleApplication</key>
-			<array>
-				<dict>
-					<key>UISceneClassName</key>
-					<string>UIWindowScene</string>
-					<key>UISceneDelegateClassName</key>
-					<string>FlutterSceneDelegate</string>
-					<key>UISceneConfigurationName</key>
-					<string>flutter</string>
-					<key>UISceneStoryboardFile</key>
-					<string>Main</string>
-				</dict>
-			</array>
-		</dict>
-	</dict>
+	<key>AppGroupId</key>
+	<string>$(CUSTOM_GROUP_ID)</string>
 	<key>CADisableMinimumFrameDurationOnPhone</key>
 	<true/>
 	<key>CFBundleDevelopmentRegion</key>
@@ -43,6 +24,17 @@
 	<string>$(FLUTTER_BUILD_NAME)</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
+	<key>CFBundleURLTypes</key>
+	<array>
+		<dict>
+			<key>CFBundleTypeRole</key>
+			<string>Editor</string>
+			<key>CFBundleURLSchemes</key>
+			<array>
+				<string>SharingMedia-$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+			</array>
+		</dict>
+	</array>
 	<key>CFBundleVersion</key>
 	<string>$(FLUTTER_BUILD_NUMBER)</string>
 	<key>FIREBASE_ANALYTICS_COLLECTION_ENABLED</key>
@@ -51,10 +43,10 @@
 	<false/>
 	<key>FlutterDeepLinkingEnabled</key>
 	<false/>
-	<key>LSRequiresIPhoneOS</key>
-	<true/>
 	<key>ITSAppUsesNonExemptEncryption</key>
 	<false/>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
 	<key>NSCameraUsageDescription</key>
 	<string>Use your camera to make photos or videos and share them encrypted with your friends.</string>
 	<key>NSFaceIDUsageDescription</key>
@@ -63,12 +55,39 @@
 	<string>Use your microphone to enable audio when making videos.</string>
 	<key>NSPhotoLibraryUsageDescription</key>
 	<string>twonly will save photos or videos to your library.</string>
+	<key>UIApplicationSceneManifest</key>
+	<dict>
+		<key>UIApplicationSupportsMultipleScenes</key>
+		<false/>
+		<key>UISceneConfigurations</key>
+		<dict>
+			<key>UIWindowSceneSessionRoleApplication</key>
+			<array>
+				<dict>
+					<key>UISceneClassName</key>
+					<string>UIWindowScene</string>
+					<key>UISceneConfigurationName</key>
+					<string>flutter</string>
+					<key>UISceneDelegateClassName</key>
+					<string>FlutterSceneDelegate</string>
+					<key>UISceneStoryboardFile</key>
+					<string>Main</string>
+				</dict>
+			</array>
+		</dict>
+	</dict>
 	<key>UIApplicationSupportsIndirectInputEvents</key>
 	<true/>
 	<key>UIBackgroundModes</key>
 	<array>
 		<string>fetch</string>
 		<string>remote-notification</string>
+		<string>processing</string>
+	</array>
+	<key>BGTaskSchedulerPermittedIdentifiers</key>
+	<array>
+		<string>eu.twonly.periodic_task</string>
+		<string>eu.twonly.processing_task</string>
 	</array>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>
@@ -89,19 +108,5 @@
 	</array>
 	<key>firebase_performance_collection_deactivated</key>
 	<true/>
-
-	<key>AppGroupId</key>
-    <string>$(CUSTOM_GROUP_ID)</string>
-    <key>CFBundleURLTypes</key>
-	<array>
-		<dict>
-			<key>CFBundleTypeRole</key>
-			<string>Editor</string>
-			<key>CFBundleURLSchemes</key>
-			<array>
-				<string>SharingMedia-$(PRODUCT_BUNDLE_IDENTIFIER)</string>
-			</array>
-		</dict>
-	</array>
 </dict>
 </plist>

lib/globals.dart

@@ -31,7 +31,9 @@ void Function(SubscriptionPlan plan) globalCallbackUpdatePlan = (plan) {};
 Map<String, VoidCallback> globalUserDataChangedCallBack = {};
 
 bool globalIsAppInBackground = true;
+bool globalIsInBackgroundTask = false;
 bool globalAllowErrorTrackingViaSentry = false;
+bool globalGotMessageFromServer = false;
 
 late String globalApplicationCacheDirectory;
 late String globalApplicationSupportDirectory;

lib/main.dart

@@ -17,9 +17,10 @@ import 'package:twonly/src/services/api.service.dart';
 import 'package:twonly/src/services/api/mediafiles/download.service.dart';
 import 'package:twonly/src/services/api/mediafiles/media_background.service.dart';
 import 'package:twonly/src/services/api/mediafiles/upload.service.dart';
+import 'package:twonly/src/services/background/callback_dispatcher.background.dart';
 import 'package:twonly/src/services/backup/create.backup.dart';
-import 'package:twonly/src/services/fcm.service.dart';
 import 'package:twonly/src/services/mediafiles/mediafile.service.dart';
+import 'package:twonly/src/services/notifications/fcm.notifications.dart';
 import 'package:twonly/src/services/notifications/setup.notifications.dart';
 import 'package:twonly/src/utils/avatars.dart';
 import 'package:twonly/src/utils/log.dart';
@@ -46,6 +47,7 @@ void main() async {
     }
 
     unawaited(performTwonlySafeBackup());
+    unawaited(initializeBackgroundTaskManager());
   } else {
     Log.info('User is not yet register. Ensure all local data is removed.');
     await deleteLocalUserData();

lib/src/constants/keyvalue.keys.dart

@@ -0,0 +1,4 @@
+class KeyValueKeys {
+  static const String lastPeriodicTaskExecution =
+      'last_periodic_task_execution';
+}

lib/src/database/daos/mediafiles.dao.dart

@@ -121,6 +121,7 @@ class MediaFilesDao extends DatabaseAccessor<TwonlyDB>
           ..where(
             (t) => (t.uploadState.equals(UploadState.initialized.name) |
                 t.uploadState.equals(UploadState.uploadLimitReached.name) |
+                t.uploadState.equals(UploadState.uploading.name) |
                 t.uploadState.equals(UploadState.preprocessing.name)),
           ))
         .get();

lib/src/database/daos/receipts.dao.dart

@@ -4,6 +4,7 @@ import 'package:hashlib/random.dart';
 import 'package:twonly/src/database/tables/messages.table.dart';
 import 'package:twonly/src/database/tables/receipts.table.dart';
 import 'package:twonly/src/database/twonly.db.dart';
+import 'package:twonly/src/services/api/mediafiles/upload.service.dart';
 import 'package:twonly/src/utils/log.dart';
 
 part 'receipts.dao.g.dart';
@@ -33,6 +34,7 @@ class ReceiptsDao extends DatabaseAccessor<TwonlyDB> with _$ReceiptsDaoMixin {
           type: const Value(MessageActionType.ackByUserAt),
         ),
       );
+      await handleMediaRelatedResponseFromReceiver(receipt.messageId!);
     }
 
     await (delete(receipts)

lib/src/services/api.service.dart

@@ -30,9 +30,9 @@ import 'package:twonly/src/services/api/mediafiles/upload.service.dart';
 import 'package:twonly/src/services/api/messages.dart';
 import 'package:twonly/src/services/api/server_messages.dart';
 import 'package:twonly/src/services/api/utils.dart';
-import 'package:twonly/src/services/fcm.service.dart';
 import 'package:twonly/src/services/flame.service.dart';
 import 'package:twonly/src/services/group.services.dart';
+import 'package:twonly/src/services/notifications/fcm.notifications.dart';
 import 'package:twonly/src/services/notifications/pushkeys.notifications.dart';
 import 'package:twonly/src/services/signal/identity.signal.dart';
 import 'package:twonly/src/services/signal/utils.signal.dart';
@@ -90,7 +90,11 @@ class ApiService {
     await initFCMAfterAuthenticated();
     globalCallbackConnectionState(isConnected: true);
 
-    if (!globalIsAppInBackground) {
+    if (globalIsInBackgroundTask) {
+      await retransmitRawBytes();
+      await tryTransmitMessages();
+      await tryDownloadAllMediaFiles();
+    } else if (!globalIsAppInBackground) {
       unawaited(retransmitRawBytes());
       unawaited(tryTransmitMessages());
       unawaited(tryDownloadAllMediaFiles());
@@ -124,6 +128,7 @@ class ApiService {
   }
 
   Future<void> startReconnectionTimer() async {
+    if (globalIsInBackgroundTask) return;
     if (reconnectionTimer?.isActive ?? false) {
       return;
     }
@@ -330,7 +335,9 @@ class ApiService {
       }
     }
     if (res.isError) {
-      Log.warn('Got error from server: ${res.error}');
+      if (res.error != ErrorCode.ForegroundSessionConnected) {
+        Log.warn('Got error from server: ${res.error}');
+      }
       if (res.error == ErrorCode.AppVersionOutdated) {
         globalCallbackAppIsOutdated();
         Log.warn('App Version is OUTDATED.');
@@ -395,6 +402,7 @@ class ApiService {
         ..userId = Int64(userId)
         ..appVersion = (await PackageInfo.fromPlatform()).version
         ..deviceId = Int64(user.deviceId)
+        ..inBackground = globalIsInBackgroundTask
         ..authToken = base64Decode(apiAuthToken);
 
       final handshake = Handshake()..authenticate = authenticate;
@@ -404,12 +412,19 @@ class ApiService {
 
       if (result.isSuccess) {
         Log.info('websocket is authenticated');
-        unawaited(onAuthenticated());
+        if (globalIsInBackgroundTask) {
+          await onAuthenticated();
+        } else {
+          unawaited(onAuthenticated());
+        }
         return true;
       }
       if (result.isError) {
-        if (result.error != ErrorCode.AuthTokenNotValid) {
-          Log.error('got error while authenticating to the server: $result');
+        if (result.error != ErrorCode.AuthTokenNotValid &&
+            result.error != ErrorCode.ForegroundSessionConnected) {
+          Log.error(
+            'got error while authenticating to the server: ${result.error}',
+          );
           return false;
         }
       }

lib/src/services/api/client2client/reaction.c2c.dart

@@ -1,6 +1,7 @@
 import 'package:clock/clock.dart';
 import 'package:twonly/globals.dart';
 import 'package:twonly/src/model/protobuf/client/generated/messages.pb.dart';
+import 'package:twonly/src/services/api/mediafiles/upload.service.dart';
 import 'package:twonly/src/utils/log.dart';
 
 Future<void> handleReaction(
@@ -17,6 +18,8 @@ Future<void> handleReaction(
     reaction.remove,
   );
 
+  await handleMediaRelatedResponseFromReceiver(reaction.targetMessageId);
+
   if (!reaction.remove) {
     await twonlyDB.groupsDao.increaseLastMessageExchange(groupId, clock.now());
   }

lib/src/services/api/mediafiles/media_background.service.dart

@@ -1,7 +1,6 @@
 import 'dart:async';
 
 import 'package:background_downloader/background_downloader.dart';
-import 'package:clock/clock.dart';
 import 'package:drift/drift.dart' show Value;
 import 'package:flutter/foundation.dart';
 import 'package:twonly/globals.dart';
@@ -75,30 +74,7 @@ Future<void> handleUploadStatusUpdate(TaskStatusUpdate update) async {
   if (update.status == TaskStatus.complete) {
     if (update.responseStatusCode == 200) {
       Log.info('Upload of ${media.mediaId} success!');
-
-      await twonlyDB.mediaFilesDao.updateMedia(
-        media.mediaId,
-        const MediaFilesCompanion(
-          uploadState: Value(UploadState.uploaded),
-        ),
-      );
-
-      /// As the messages where send in a bulk acknowledge all messages.
-
-      final messages =
-          await twonlyDB.messagesDao.getMessagesByMediaId(media.mediaId);
-      for (final message in messages) {
-        final contacts =
-            await twonlyDB.groupsDao.getGroupNonLeftMembers(message.groupId);
-        for (final contact in contacts) {
-          await twonlyDB.messagesDao.handleMessageAckByServer(
-            contact.contactId,
-            message.messageId,
-            clock.now(),
-          );
-        }
-      }
-
+      await markUploadAsSuccessful(media);
       return;
     }
     Log.error(
@@ -123,6 +99,20 @@ Future<void> handleUploadStatusUpdate(TaskStatusUpdate update) async {
     'Background status $mediaId with status ${update.status} and ${update.responseStatusCode}. ',
   );
 
+  if (update.status == TaskStatus.waitingToRetry) {
+    if (update.responseStatusCode == 401) {
+      // auth token is not valid, so either create a new task with a new token, or cancel task
+      final mediaService = MediaFileService(media);
+      await FileDownloader().cancelTaskWithId(update.task.taskId);
+      Log.info('Cancel task, already uploaded or will be reuploaded');
+      if (mediaService.mediaFile.uploadState != UploadState.uploaded) {
+        await mediaService.setUploadState(UploadState.uploading);
+        // In all other cases just try the upload again...
+        await startBackgroundMediaUpload(mediaService);
+      }
+    }
+  }
+
   if (update.status == TaskStatus.failed ||
       update.status == TaskStatus.canceled) {
     Log.error(
@@ -130,8 +120,11 @@ Future<void> handleUploadStatusUpdate(TaskStatusUpdate update) async {
     );
     final mediaService = MediaFileService(media);
 
-    await mediaService.setUploadState(UploadState.uploading);
-    // In all other cases just try the upload again...
-    await startBackgroundMediaUpload(mediaService);
+    // in case the media file is already uploaded to not reqtry
+    if (mediaService.mediaFile.uploadState != UploadState.uploaded) {
+      await mediaService.setUploadState(UploadState.uploading);
+      // In all other cases just try the upload again...
+      await startBackgroundMediaUpload(mediaService);
+    }
   }
 }

lib/src/services/api/mediafiles/upload.service.dart

@@ -24,11 +24,14 @@ import 'package:twonly/src/services/flame.service.dart';
 import 'package:twonly/src/services/mediafiles/mediafile.service.dart';
 import 'package:twonly/src/utils/log.dart';
 import 'package:twonly/src/utils/misc.dart';
+import 'package:workmanager/workmanager.dart' hide TaskStatus;
 
 Future<void> finishStartedPreprocessing() async {
   final mediaFiles =
       await twonlyDB.mediaFilesDao.getAllMediaFilesPendingUpload();
 
+  Log.info('There are ${mediaFiles.length} media files pending');
+
   for (final mediaFile in mediaFiles) {
     if (mediaFile.isDraftMedia) {
       continue;
@@ -55,6 +58,47 @@ Future<void> finishStartedPreprocessing() async {
   }
 }
 
+/// It can happen, that a media files is uploaded but not yet marked for been uploaded.
+/// For example because the background_downloader plugin has not yet reported the finished upload.
+/// In case the the message receipts or a reaction was received, mark the media file as been uploaded.
+Future<void> handleMediaRelatedResponseFromReceiver(String messageId) async {
+  final message =
+      await twonlyDB.messagesDao.getMessageById(messageId).getSingleOrNull();
+  if (message == null || message.mediaId == null) return;
+  final media = await twonlyDB.mediaFilesDao.getMediaFileById(message.mediaId!);
+  if (media == null) return;
+
+  if (media.uploadState != UploadState.uploaded) {
+    Log.info('Media was not yet marked as uploaded. Doing it now.');
+    await markUploadAsSuccessful(media);
+  }
+}
+
+Future<void> markUploadAsSuccessful(MediaFile media) async {
+  await twonlyDB.mediaFilesDao.updateMedia(
+    media.mediaId,
+    const MediaFilesCompanion(
+      uploadState: Value(UploadState.uploaded),
+    ),
+  );
+
+  /// As the messages where send in a bulk acknowledge all messages.
+
+  final messages =
+      await twonlyDB.messagesDao.getMessagesByMediaId(media.mediaId);
+  for (final message in messages) {
+    final contacts =
+        await twonlyDB.groupsDao.getGroupNonLeftMembers(message.groupId);
+    for (final contact in contacts) {
+      await twonlyDB.messagesDao.handleMessageAckByServer(
+        contact.contactId,
+        message.messageId,
+        clock.now(),
+      );
+    }
+  }
+}
+
 Future<MediaFileService?> initializeMediaUpload(
   MediaType type,
   int? displayLimitInMilliseconds, {
@@ -344,8 +388,9 @@ Future<void> _uploadUploadRequest(MediaFileService media) async {
 
     final connectivityResult = await Connectivity().checkConnectivity();
 
-    if (!connectivityResult.contains(ConnectivityResult.mobile) &&
-        !connectivityResult.contains(ConnectivityResult.wifi)) {
+    if (globalIsInBackgroundTask ||
+        !connectivityResult.contains(ConnectivityResult.mobile) &&
+            !connectivityResult.contains(ConnectivityResult.wifi)) {
       // no internet, directly put it into the background...
       await FileDownloader().enqueue(task);
       await media.setUploadState(UploadState.backgroundUploadTaskStarted);
@@ -376,15 +421,30 @@ Future<void> uploadFileFastOrEnqueue(
   );
 
   try {
+    final workmanagerUniqueName =
+        'progressing_finish_uploads_${media.mediaFile.mediaId}';
+
+    await Workmanager().registerOneOffTask(
+      workmanagerUniqueName,
+      'eu.twonly.processing_task',
+      initialDelay: const Duration(minutes: 15),
+      constraints: Constraints(
+        networkType: NetworkType.connected,
+      ),
+    );
+
     Log.info('Uploading fast: ${task.taskId}');
-    final response =
-        await requestMultipart.send().timeout(const Duration(seconds: 8));
+
+    final response = await requestMultipart.send();
     var status = TaskStatus.failed;
     if (response.statusCode == 200) {
       status = TaskStatus.complete;
     } else if (response.statusCode == 404) {
       status = TaskStatus.notFound;
     }
+
+    await Workmanager().cancelByUniqueName(workmanagerUniqueName);
+
     await handleUploadStatusUpdate(
       TaskStatusUpdate(
         task,

lib/src/services/api/server_messages.dart

@@ -63,6 +63,7 @@ Future<void> handleServerMessage(server.ServerToClient msg) async {
       ..response = response;
 
     await apiService.sendResponse(ClientToServer()..v0 = v0);
+    globalGotMessageFromServer = true;
   });
 }
 

lib/src/services/background/callback_dispatcher.background.dart

@@ -0,0 +1,130 @@
+import 'dart:async';
+import 'package:path_provider/path_provider.dart';
+import 'package:sentry_flutter/sentry_flutter.dart';
+import 'package:twonly/globals.dart';
+import 'package:twonly/src/constants/keyvalue.keys.dart';
+import 'package:twonly/src/database/twonly.db.dart';
+import 'package:twonly/src/services/api.service.dart';
+import 'package:twonly/src/services/api/mediafiles/upload.service.dart';
+import 'package:twonly/src/utils/keyvalue.dart';
+import 'package:twonly/src/utils/log.dart';
+import 'package:twonly/src/utils/storage.dart';
+import 'package:workmanager/workmanager.dart';
+
+// ignore: unreachable_from_main
+Future<void> initializeBackgroundTaskManager() async {
+  await Workmanager().initialize(callbackDispatcher);
+
+  await Workmanager().registerPeriodicTask(
+    'fetch_data_from_server',
+    'eu.twonly.periodic_task',
+    frequency: const Duration(minutes: 20),
+    initialDelay: const Duration(minutes: 5),
+    constraints: Constraints(
+      networkType: NetworkType.connected,
+    ),
+  );
+}
+
+@pragma('vm:entry-point')
+void callbackDispatcher() {
+  Workmanager().executeTask((task, inputData) async {
+    switch (task) {
+      case 'eu.twonly.periodic_task':
+        if (await initBackgroundExecution()) {
+          await handlePeriodicTask();
+        }
+      case 'eu.twonly.processing_task':
+        if (await initBackgroundExecution()) {
+          await handleProcessingTask();
+        }
+      default:
+        Log.error('Unknown task was executed: $task');
+    }
+    return Future.value(true);
+  });
+}
+
+Future<bool> initBackgroundExecution() async {
+  SentryWidgetsFlutterBinding.ensureInitialized();
+  initLogger();
+
+  final user = await getUser();
+  if (user == null) return false;
+  gUser = user;
+
+  globalApplicationCacheDirectory = (await getApplicationCacheDirectory()).path;
+  globalApplicationSupportDirectory =
+      (await getApplicationSupportDirectory()).path;
+
+  twonlyDB = TwonlyDB();
+  apiService = ApiService();
+  globalIsInBackgroundTask = true;
+
+  return true;
+}
+
+Future<bool> handlePeriodicTask() async {
+  final lastExecution =
+      await KeyValueStore.get(KeyValueKeys.lastPeriodicTaskExecution);
+  if (lastExecution == null || !lastExecution.containsKey('timestamp')) {
+    final lastExecutionTime = lastExecution?['timestamp'] as int?;
+    if (lastExecutionTime != null) {
+      final lastExecution =
+          DateTime.fromMillisecondsSinceEpoch(lastExecutionTime);
+      if (DateTime.now().difference(lastExecution).inMinutes < 2) {
+        Log.info(
+          'eu.twonly.periodic_task not executed as last execution was within the last two minutes.',
+        );
+        return true;
+      }
+    }
+  }
+
+  await KeyValueStore.put(KeyValueKeys.lastPeriodicTaskExecution, {
+    'timestamp': DateTime.now().millisecondsSinceEpoch,
+  });
+
+  Log.info('eu.twonly.periodic_task was called.');
+
+  final stopwatch = Stopwatch()..start();
+
+  if (!await apiService.connect()) {
+    Log.info('Could not connect to the api. Returning early.');
+    return false;
+  }
+
+  if (!apiService.isAuthenticated) {
+    Log.info('Api is not authenticated. Returning early.');
+    return false;
+  }
+
+  while (!globalGotMessageFromServer) {
+    if (stopwatch.elapsed.inSeconds >= 15) {
+      Log.info('No new message from the server after 15 seconds.');
+      break;
+    }
+    await Future.delayed(const Duration(milliseconds: 500));
+  }
+
+  if (globalGotMessageFromServer) {
+    Log.info('Received a server message from the server.');
+  }
+
+  await finishStartedPreprocessing();
+
+  await Future.delayed(const Duration(milliseconds: 2000));
+
+  await apiService.close(() {});
+  stopwatch.stop();
+
+  Log.info('eu.twonly.periodic_task finished after ${stopwatch.elapsed}.');
+  return true;
+}
+
+Future<void> handleProcessingTask() async {
+  Log.info('eu.twonly.processing_task was called.');
+  final stopwatch = Stopwatch()..start();
+  await finishStartedPreprocessing();
+  Log.info('eu.twonly.processing_task finished after ${stopwatch.elapsed}.');
+}

lib/src/services/notifications/fcm.notifications.dart

@@ -8,11 +8,12 @@ import 'package:firebase_messaging/firebase_messaging.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import 'package:twonly/globals.dart';
 import 'package:twonly/src/constants/secure_storage_keys.dart';
+import 'package:twonly/src/services/background/callback_dispatcher.background.dart';
 import 'package:twonly/src/services/notifications/background.notifications.dart';
 import 'package:twonly/src/utils/log.dart';
 import 'package:twonly/src/utils/storage.dart';
 
-import '../../firebase_options.dart';
+import '../../../firebase_options.dart';
 
 // see more here: https://firebase.google.com/docs/cloud-messaging/flutter/receive?hl=de
 
@@ -111,8 +112,15 @@ Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
   initLogger();
   // Log.info('Handling a background message: ${message.messageId}');
   await handleRemoteMessage(message);
-  // make sure every thing run...
-  await Future.delayed(const Duration(milliseconds: 2000));
+
+  if (Platform.isAndroid) {
+    if (await initBackgroundExecution()) {
+      await handlePeriodicTask();
+    }
+  } else {
+    // make sure every thing run...
+    await Future.delayed(const Duration(milliseconds: 2000));
+  }
 }
 
 Future<void> handleRemoteMessage(RemoteMessage message) async {

lib/src/views/settings/notification.view.dart

@@ -7,7 +7,7 @@ import 'package:hashlib/random.dart';
 import 'package:twonly/globals.dart';
 import 'package:twonly/src/constants/secure_storage_keys.dart';
 import 'package:twonly/src/model/protobuf/client/generated/push_notification.pb.dart';
-import 'package:twonly/src/services/fcm.service.dart';
+import 'package:twonly/src/services/notifications/fcm.notifications.dart';
 import 'package:twonly/src/services/notifications/pushkeys.notifications.dart';
 import 'package:twonly/src/utils/misc.dart';
 import 'package:twonly/src/utils/storage.dart';