FCM push Notifications

lib/main.dart

@@ -22,17 +22,12 @@ import 'services/notification_bridge.dart';
 
 /// Handle messages received while the app is terminated or in background.
 Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
-  // initialize plugin in background isolate
-  await NotificationService.initialize();
-  final notification = message.notification;
-  if (notification != null) {
-    NotificationService.show(
-      id: DateTime.now().millisecondsSinceEpoch ~/ 1000,
-      title: notification.title ?? 'Notification',
-      body: notification.body ?? '',
-      payload: message.data['payload'],
-    );
-  }
+  // Do minimal work in background isolate. Avoid initializing Flutter
+  // plugins here (e.g. flutter_local_notifications) as that can hang
+  // the background isolate and interfere with subsequent launches.
+  // If you need to persist data from a background message, perform a
+  // lightweight HTTP call or write to a background-capable DB.
+  return;
 }
 
 Future<void> main() async {
@@ -58,22 +53,9 @@ Future<void> main() async {
 
   await Supabase.initialize(url: supabaseUrl, anonKey: supabaseAnonKey);
 
-  // ensure token saved right away if already signed in
+  // ensure token saved shortly after startup if already signed in.
+  // Run this after runApp so startup is not blocked by network/token ops.
   final supaClient = Supabase.instance.client;
-  String? initialToken;
-  if (!kIsWeb) {
-    try {
-      initialToken = await FirebaseMessaging.instance.getToken();
-    } catch (e) {
-      debugPrint('FCM getToken failed: $e');
-      initialToken = null;
-    }
-    if (initialToken != null && supaClient.auth.currentUser != null) {
-      debugPrint('initial FCM token for signed-in user: $initialToken');
-      final ctrl = NotificationsController(supaClient);
-      await ctrl.registerFcmToken(initialToken);
-    }
-  }
 
   // listen for auth changes to register/unregister token accordingly
   supaClient.auth.onAuthStateChange.listen((data) async {
@@ -152,6 +134,24 @@ Future<void> main() async {
       ),
     ),
   );
+
+  // Post-startup: register current FCM token without blocking UI.
+  if (!kIsWeb) {
+    Future.microtask(() async {
+      try {
+        final token = await FirebaseMessaging.instance.getToken().timeout(
+          const Duration(seconds: 10),
+        );
+        if (token != null && supaClient.auth.currentUser != null) {
+          debugPrint('post-startup registering FCM token: $token');
+          final ctrl = NotificationsController(supaClient);
+          await ctrl.registerFcmToken(token);
+        }
+      } catch (e) {
+        debugPrint('post-startup FCM token registration failed: $e');
+      }
+    });
+  }
 }
 
 class NotificationSoundObserver extends ProviderObserver {

lib/providers/auth_provider.dart

@@ -2,6 +2,9 @@ import 'dart:async';
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:supabase_flutter/supabase_flutter.dart';
+import 'package:firebase_messaging/firebase_messaging.dart';
+import 'notifications_provider.dart';
+import '../utils/device_id.dart';
 
 import 'supabase_provider.dart';
 
@@ -64,6 +67,23 @@ class AuthController {
   }
 
   Future<void> signOut() {
+    // Attempt to unregister this device's FCM token before signing out.
+    return _doSignOut();
+  }
+
+  Future<void> _doSignOut() async {
+    try {
+      final userId = _client.auth.currentUser?.id;
+      if (userId != null) {
+        try {
+          final token = await FirebaseMessaging.instance.getToken();
+          if (token != null) {
+            final ctrl = NotificationsController(_client);
+            await ctrl.unregisterFcmToken(token);
+          }
+        } catch (_) {}
+      }
+    } catch (_) {}
     return _client.auth.signOut();
   }
 }

lib/providers/notifications_provider.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/foundation.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:supabase_flutter/supabase_flutter.dart';
+import '../utils/device_id.dart';
 
 import '../models/notification_item.dart';
 import 'profile_provider.dart';
@@ -165,10 +166,16 @@ class NotificationsController {
   Future<void> registerFcmToken(String token) async {
     final userId = _client.auth.currentUser?.id;
     if (userId == null) return;
-    final res = await _client.from('fcm_tokens').insert({
+    final deviceId = await DeviceId.getId();
+    // upsert using a unique constraint on (user_id, device_id) so a single
+    // device keeps its token updated without overwriting other devices.
+    final payload = {
       'user_id': userId,
+      'device_id': deviceId,
       'token': token,
-    });
+      'created_at': DateTime.now().toUtc().toIso8601String(),
+    };
+    final res = await _client.from('fcm_tokens').upsert(payload);
     if (res == null) {
       debugPrint(
         'registerFcmToken: null response for user=$userId token=$token',
@@ -189,11 +196,14 @@ class NotificationsController {
   Future<void> unregisterFcmToken(String token) async {
     final userId = _client.auth.currentUser?.id;
     if (userId == null) return;
+    final deviceId = await DeviceId.getId();
+    // Prefer to delete by device_id to avoid removing other devices' tokens.
     final res = await _client
         .from('fcm_tokens')
         .delete()
         .eq('user_id', userId)
-        .eq('token', token);
+        .eq('device_id', deviceId)
+        .or('token.eq.$token');
     if (res == null) {
       debugPrint(
         'unregisterFcmToken: null response for user=$userId token=$token',

lib/utils/device_id.dart

@@ -0,0 +1,23 @@
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:uuid/uuid.dart';
+
+class DeviceId {
+  static const _key = 'tasq_device_id';
+
+  /// Returns a stable UUID for this installation. Generated once and persisted
+  /// in `SharedPreferences`.
+  static Future<String> getId() async {
+    final prefs = await SharedPreferences.getInstance();
+    var id = prefs.getString(_key);
+    if (id != null && id.isNotEmpty) return id;
+    id = const Uuid().v4();
+    await prefs.setString(_key, id);
+    return id;
+  }
+
+  /// For testing or explicit reset.
+  static Future<void> reset() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.remove(_key);
+  }
+}