feat: add undo for memory deleted by swiping (#2808)

Closes #2687 

Demo:


https://github.com/user-attachments/assets/c4f3371a-3f74-4f31-9b60-4ed05067760e

Author: aaravgarg

app/lib/pages/memories/page.dart

@@ -59,6 +59,7 @@ class MemoriesPageState extends State<MemoriesPage> with AutomaticKeepAliveClien
   MemoryCategory? _selectedCategory;
   final ScrollController _scrollController = ScrollController();
 
+  OverlayEntry? _deleteNotificationOverlay;
   // Filter options for the dropdown
   // Default will be set in initState based on current date
   late FilterOption _currentFilter;
@@ -67,9 +68,91 @@ class MemoriesPageState extends State<MemoriesPage> with AutomaticKeepAliveClien
   void dispose() {
     _searchController.dispose();
     _scrollController.dispose();
+    _removeDeleteNotification();
     super.dispose();
   }
 
+  // Remove the delete notification overlay if it exists
+  void _removeDeleteNotification() {
+    _deleteNotificationOverlay?.remove();
+    _deleteNotificationOverlay = null;
+  }
+
+  void showDeleteNotification(String memoryContent, Memory? memory) {
+    _removeDeleteNotification();
+
+    final provider = Provider.of<MemoriesProvider>(this.context, listen: false);
+
+    _deleteNotificationOverlay = OverlayEntry(
+      builder: (_) => Positioned(
+        bottom: 20,
+        left: 0,
+        right: 0,
+        child: Center(
+          child: Material(
+            color: Colors.transparent,
+            child: Container(
+              width: MediaQuery.of(this.context).size.width * 0.9,
+              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+              decoration: BoxDecoration(
+                color: Colors.black87,
+                borderRadius: BorderRadius.circular(8),
+                boxShadow: [
+                  BoxShadow(
+                    color: Colors.black.withOpacity(0.2),
+                    blurRadius: 4,
+                    offset: const Offset(0, 2),
+                  ),
+                ],
+              ),
+              child: Row(
+                children: [
+                  Expanded(
+                    child: Text(
+                      'Memory Deleted.',
+                      style: const TextStyle(color: Colors.white, fontSize: 14),
+                    ),
+                  ),
+                  TextButton(
+                    onPressed: () async {
+                      final success = await provider.restoreLastDeletedMemory();
+                      if (success) {
+                        _removeDeleteNotification();
+                      }
+                    },
+                    style: TextButton.styleFrom(
+                      padding: EdgeInsets.symmetric(horizontal: 8),
+                      minimumSize: Size(0, 36),
+                    ),
+                    child: Text(
+                      'Undo',
+                      style: TextStyle(color: Colors.blue, fontWeight: FontWeight.w500),
+                    ),
+                  ),
+                  IconButton(
+                    onPressed: () {
+                      _removeDeleteNotification();
+                    },
+                    icon: Icon(Icons.close, color: Colors.white70, size: 20),
+                    padding: EdgeInsets.zero,
+                    constraints: BoxConstraints(),
+                    splashRadius: 20,
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+
+    Overlay.of(this.context).insert(_deleteNotificationOverlay!);
+
+    Future.delayed(const Duration(seconds: 10), () {
+      _removeDeleteNotification();
+    });
+  }
+
   @override
   void initState() {
     super.initState();

app/lib/pages/memories/widgets/memory_item.dart

@@ -5,6 +5,7 @@ import 'package:omi/providers/memories_provider.dart';
 import 'package:omi/utils/analytics/mixpanel.dart';
 import 'package:omi/utils/ui_guidelines.dart';
 import 'package:omi/widgets/extensions/string.dart';
+import 'package:omi/pages/memories/page.dart';
 
 import 'delete_confirmation.dart';
 
@@ -61,8 +62,14 @@ class MemoryItem extends StatelessWidget {
         return shouldDelete;
       },
       onDismissed: (direction) {
+        final memoryContent = memory.content.decodeString;
+
         provider.deleteMemory(memory);
         MixpanelManager().memoriesPageDeletedMemory(memory);
+
+        if (context.findAncestorStateOfType<MemoriesPageState>() != null) {
+          context.findAncestorStateOfType<MemoriesPageState>()!.showDeleteNotification(memoryContent, memory);
+        }
       },
       background: Container(
         margin: const EdgeInsets.only(bottom: AppStyles.spacingM),

app/lib/providers/memories_provider.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'package:omi/widgets/extensions/string.dart';
 import 'package:omi/backend/http/api/memories.dart';
 import 'package:omi/backend/preferences.dart';
@@ -96,11 +97,66 @@ class MemoriesProvider extends ChangeNotifier {
     _setCategories();
   }
 
-  void deleteMemory(Memory memory) async {
-    await deleteMemoryServer(memory.id);
+  Memory? _lastDeletedMemory;
+  Timer? _deletionTimer;
+  String? _pendingDeletionId;
+
+  Memory? get lastDeletedMemory => _lastDeletedMemory;
+
+  void deleteMemory(Memory memory) {
+    _cancelDeletionTimer();
+
+    _lastDeletedMemory = memory;
+    _pendingDeletionId = memory.id;
+
     _memories.remove(memory);
     _unreviewed.remove(memory);
     _setCategories();
+    notifyListeners();
+
+    _startDeletionTimer();
+  }
+
+  void _cancelDeletionTimer() {
+    if (_deletionTimer != null && _deletionTimer!.isActive) {
+      _deletionTimer!.cancel();
+      _deletionTimer = null;
+    }
+  }
+
+  void _startDeletionTimer() {
+    _deletionTimer = Timer(const Duration(seconds: 10), () {
+      _executeServerDeletion();
+    });
+  }
+
+  Future<void> _executeServerDeletion() async {
+    if (_pendingDeletionId != null) {
+      await deleteMemoryServer(_pendingDeletionId!);
+      _pendingDeletionId = null;
+    }
+  }
+
+  // Restore the last deleted memory
+  Future<bool> restoreLastDeletedMemory() async {
+    if (_lastDeletedMemory == null) return false;
+
+    _cancelDeletionTimer();
+    _pendingDeletionId = null;
+
+    _memories.add(_lastDeletedMemory!);
+    if (!_lastDeletedMemory!.reviewed &&
+        _lastDeletedMemory!.createdAt.isAfter(DateTime.now().subtract(const Duration(days: 1)))) {
+      _unreviewed.add(_lastDeletedMemory!);
+    }
+
+    _setCategories();
+    notifyListeners();
+
+    final restoredMemory = _lastDeletedMemory;
+    _lastDeletedMemory = null;
+
+    return true;
   }
 
   void deleteAllMemories() async {