Bugfixes + BG task seems to work

lib/main.dart

@@ -1,11 +1,42 @@
 import 'package:flutter/material.dart';
 import 'package:obtainium/pages/apps.dart';
 import 'package:obtainium/services/apps_provider.dart';
+import 'package:obtainium/services/source_service.dart';
 import 'package:provider/provider.dart';
-import 'package:toast/toast.dart';
+import 'package:workmanager/workmanager.dart';
+
+void backgroundUpdateCheck() {
+  Workmanager().executeTask((task, inputData) async {
+    var appsProvider = AppsProvider(bg: true);
+    await appsProvider.loadApps();
+    List<App> updates = await appsProvider.getUpdates();
+    if (updates.isNotEmpty) {
+      String message = updates.length == 1
+          ? '${updates[0].name} has an update.'
+          : '${(updates.length == 2 ? '${updates[0].name} and ${updates[1].name}' : '${updates[0].name} and ${updates.length - 1} more apps')} have updates.';
+      appsProvider.downloaderNotifications.cancel(2);
+      appsProvider.notify(
+          2,
+          'Updates Available',
+          message,
+          'UPDATES_AVAILABLE',
+          'Updates Available',
+          'Notifies the user that updates are available for one or more Apps tracked by Obtainium');
+    }
+    return Future.value(true);
+  });
+}
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  Workmanager().initialize(
+    backgroundUpdateCheck,
+  );
+  await Workmanager().cancelByUniqueName('update-apps-task');
+  await Workmanager().registerPeriodicTask(
+      'update-apps-task', 'backgroundUpdateCheck',
+      frequency: const Duration(minutes: 15),
+      constraints: Constraints(networkType: NetworkType.connected));
   runApp(MultiProvider(
     providers: [ChangeNotifierProvider(create: (context) => AppsProvider())],
     child: const MyApp(),

lib/services/apps_provider.dart

@@ -19,11 +19,14 @@ class AppsProvider with ChangeNotifier {
   bool loadingApps = false;
   bool gettingUpdates = false;
 
-  AppsProvider() {
-    initializeDownloader();
+  AppsProvider({bool bg = false}) {
+    initializeNotifs();
     loadApps().then((_) {
       clearDownloadStates();
     });
+    if (!bg) {
+      initializeDownloader();
+    }
   }
 
   // Notifications plugin for downloads
@@ -53,15 +56,19 @@ class AppsProvider with ChangeNotifier {
       int progress = data[2];
       downloadCallbackForeground(id, status, progress);
     });
-    // Initialize the notifications service
-    await downloaderNotifications.initialize(const InitializationSettings(
-        android: AndroidInitializationSettings('ic_launcher')));
     // Subscribe to changes in the app foreground status
     foregroundSubscription = FGBGEvents.stream.listen((event) async {
       isForeground = event == FGBGType.foreground;
+      if (isForeground) await loadApps();
     });
   }
 
+  Future<void> initializeNotifs() async {
+    // Initialize the notifications service
+    await downloaderNotifications.initialize(const InitializationSettings(
+        android: AndroidInitializationSettings('ic_launcher')));
+  }
+
   // Callback that receives FlutterDownloader status and forwards to a foreground function
   @pragma('vm:entry-point')
   static void downloadCallbackBackground(
@@ -71,24 +78,33 @@ class AppsProvider with ChangeNotifier {
     send!.send([id, status, progress]);
   }
 
+  Future<void> notify(int id, String title, String message, String channelCode,
+      String channelName, String channelDescription) {
+    return downloaderNotifications.show(
+        id,
+        title,
+        message,
+        NotificationDetails(
+            android: AndroidNotificationDetails(channelCode, channelName,
+                channelDescription: channelDescription,
+                importance: Importance.max,
+                priority: Priority.max,
+                groupKey: 'dev.imranr.obtainium.$channelCode')));
+  }
+
   // Foreground function to act on FlutterDownloader status updates (install downloaded APK)
   void downloadCallbackForeground(
       String id, DownloadTaskStatus status, int progress) async {
     if (status == DownloadTaskStatus.complete) {
       // Wait for app to come to the foreground if not already, and notify the user
       while (!isForeground) {
-        await downloaderNotifications.show(
+        await notify(
             1,
             'Complete App Installation',
             'Obtainium must be open to install Apps',
-            const NotificationDetails(
-                android: AndroidNotificationDetails(
-                    'COMPLETE_INSTALL', 'Complete App Installation',
-                    channelDescription:
-                        'Ask the user to return to Obtanium to finish installing an App',
-                    importance: Importance.max,
-                    priority: Priority.max,
-                    groupKey: 'dev.imranr.obtainium.COMPLETE_INSTALL')));
+            'COMPLETE_INSTALL',
+            'Complete App Installation',
+            'Asks the user to return to Obtanium to finish installing an App');
         if (await FGBGEvents.stream.first == FGBGType.foreground) {
           break;
         }