Add local persistence for deleted tasks

- Extended TaskService to manage a list of deleted tasks using shared_preferences.
- Modified TaskViewModel to filter out tasks that have been marked as deleted locally.
- Loaded the list of deleted tasks during app initialization in main.dart.

gui/lib/main.dart

@@ -42,6 +42,7 @@ class MyApp extends StatelessWidget {
     // Fetch services from providers
     final chatService = Provider.of<ChatService>(context, listen: false);
     final taskService = Provider.of<TaskService>(context, listen: false);
+    taskService.loadDeletedTasks();
 
     return MaterialApp(
       title: 'AutoGPT Flutter Client',

gui/lib/services/task_service.dart

@@ -1,10 +1,12 @@
 import 'package:auto_gpt_flutter_client/models/task_request_body.dart';
 import 'package:auto_gpt_flutter_client/models/task_response.dart';
 import 'package:auto_gpt_flutter_client/utils/rest_api_utility.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 /// Service class for performing task-related operations.
 class TaskService {
   final RestApiUtility api;
+  List<String> _deletedTaskIds = [];
 
   TaskService(this.api);
 
@@ -59,4 +61,21 @@ class TaskService {
       throw Exception('Failed to list task artifacts: $e');
     }
   }
+
+  Future<void> loadDeletedTasks() async {
+    _deletedTaskIds =
+        (await SharedPreferences.getInstance()).getStringList('deletedTasks') ??
+            [];
+    print("Deleted tasks fetched successfully!");
+  }
+
+  void saveDeletedTask(String taskId) {
+    _deletedTaskIds.add(taskId);
+    SharedPreferences.getInstance()
+        .then((prefs) => prefs.setStringList('deletedTasks', _deletedTaskIds));
+  }
+
+  bool isTaskDeleted(String taskId) {
+    return _deletedTaskIds.contains(taskId);
+  }
 }

gui/lib/viewmodels/task_viewmodel.dart

@@ -35,19 +35,21 @@ class TaskViewModel with ChangeNotifier {
   }
 
   /// Deletes a task.
-  void deleteTask(String id) async {
-    // TODO: Protocol doesn't support deleting tasks, we need to manually manage this list
-
-    // Update local tasks list and notify listeners
-    _tasks.removeWhere((task) => task.id == id);
+  void deleteTask(String taskId) {
+    _taskService.saveDeletedTask(taskId);
+    tasks.removeWhere((task) => task.id == taskId);
     notifyListeners();
+    print("Tasks deleted successfully!");
   }
 
   /// Fetches tasks from the data source.
   void fetchTasks() async {
     try {
       final TaskResponse tasksResponse = await _taskService.listAllTasks();
-      _tasks = tasksResponse.tasks;
+      final tasksFromApi = tasksResponse.tasks;
+      _tasks = tasksFromApi
+          .where((task) => !_taskService.isTaskDeleted(task.id))
+          .toList();
 
       notifyListeners();
       print("Tasks fetched successfully!");