refactor(memory-home-widget): streamline memory update logic and improve synchronization handling

mobile/lib/app.dart

@@ -66,8 +66,7 @@ class _EnteAppState extends State<EnteApp> with WidgetsBindingObserver {
     _memoriesChangedSubscription =
         Bus.instance.on<MemoriesChangedEvent>().listen(
       (event) async {
-        await MemoryHomeWidgetService.instance.updateMemoryChanged(true);
-        await MemoryHomeWidgetService.instance.initMemoryHW(true);
+        await MemoryHomeWidgetService.instance.memoryChanged();
       },
     );
   }

mobile/lib/services/memories_cache_service.dart

@@ -370,6 +370,10 @@ class MemoriesCacheService {
     }
   }
 
+  Future<List<SmartMemory>?> getCachedMemories() async {
+    return _cachedMemories;
+  }
+
   Future<void> goToMemoryFromGeneratedFileID(
     BuildContext context,
     int generatedFileID,

mobile/lib/services/memory_home_widget_service.dart

@@ -5,6 +5,7 @@ import "package:photos/models/file/file.dart";
 import "package:photos/service_locator.dart";
 import "package:photos/services/home_widget_service.dart";
 import "package:shared_preferences/shared_preferences.dart";
+import "package:synchronized/synchronized.dart";
 
 class MemoryHomeWidgetService {
   final Logger _logger = Logger((MemoryHomeWidgetService).toString());
@@ -16,6 +17,7 @@ class MemoryHomeWidgetService {
 
   late final SharedPreferences _prefs;
 
+  final _memoryForceRefreshLock = Lock();
   bool _hasSyncedMemory = false;
 
   static const memoryChangedKey = "memoryChanged.widget";
@@ -31,14 +33,6 @@ class MemoryHomeWidgetService {
   }
 
   Future<void> _memorySync() async {
-    final total = await _getTotal();
-    if (total == 0 || total == null) {
-      _logger.warning(
-        "sync stopped because no memory is cached yet, so nothing to sync",
-      );
-      return;
-    }
-
     final homeWidgetCount = await HomeWidgetService.instance.countHomeWidgets();
     if (homeWidgetCount == 0) {
       _logger.warning("no home widget active");
@@ -57,13 +51,20 @@ class MemoryHomeWidgetService {
       return;
     }
 
-    forceFetchNewMemories ??= await getForceFetchCondition();
+    await _memoryForceRefreshLock.synchronized(() async {
+      final isTotalEmpty = await checkIfTotalEmpty();
+      forceFetchNewMemories ??= await getForceFetchCondition(isTotalEmpty);
 
-    if (forceFetchNewMemories) {
-      await _forceMemoryUpdate();
-    } else {
-      await _memorySync();
-    }
+      _logger.warning(
+        "init memory hw: forceFetch: $forceFetchNewMemories, isTotalEmpty: $isTotalEmpty",
+      );
+
+      if (forceFetchNewMemories!) {
+        await _forceMemoryUpdate();
+      } else if (!isTotalEmpty) {
+        await _memorySync();
+      }
+    });
   }
 
   Future<void> clearWidget() async {
@@ -84,19 +85,27 @@ class MemoryHomeWidgetService {
     await _prefs.setBool(memoryChangedKey, value);
   }
 
-  Future<bool> getForceFetchCondition() async {
-    final memoryChanged = _prefs.getBool(memoryChangedKey);
+  Future<bool> checkIfTotalEmpty() async {
     final total = await _getTotal();
+    return total == 0 || total == null;
+  }
+
+  Future<bool> getForceFetchCondition(bool isTotalEmpty) async {
+    final memoryChanged = _prefs.getBool(memoryChangedKey);
+    if (memoryChanged == true) return true;
+
+    final cachedMemories = await memoriesCacheService.getCachedMemories();
 
     final forceFetchNewMemories =
-        memoryChanged == true || total == 0 || total == null;
+        isTotalEmpty && (cachedMemories?.isNotEmpty ?? false);
     return forceFetchNewMemories;
   }
 
   Future<void> checkPendingMemorySync() async {
     await Future.delayed(const Duration(seconds: 5), () {});
 
-    final forceFetchNewMemories = await getForceFetchCondition();
+    final isTotalEmpty = await checkIfTotalEmpty();
+    final forceFetchNewMemories = await getForceFetchCondition(isTotalEmpty);
 
     if (_hasSyncedMemory && !forceFetchNewMemories) {
       _logger.info(">>> Memory already synced");
@@ -141,6 +150,22 @@ class MemoryHomeWidgetService {
     _logger.info(">>> Home Widget updated");
   }
 
+  Future<void> memoryChanged() async {
+    final cachedMemories = await memoriesCacheService.getCachedMemories();
+    final currentTotal = cachedMemories?.length ?? 0;
+
+    final int total = await _getTotal() ?? 0;
+
+    if (total == currentTotal && total == 0) {
+      _logger.info(">>> Memories not changed, doing nothing");
+      return;
+    }
+
+    _logger.info(">>> Memories changed, updating widget");
+    await updateMemoryChanged(true);
+    await initMemoryHW(true);
+  }
+
   Future<int?> _getTotal() async {
     return HomeWidgetService.instance.getData<int>(totalSet);
   }

mobile/lib/ui/tabs/home_widget.dart

@@ -124,7 +124,9 @@ class _HomeWidgetState extends State<HomeWidget> {
     _logger.info("Building initstate");
     super.initState();
 
-    MemoryHomeWidgetService.instance.checkPendingMemorySync();
+    if (LocalSyncService.instance.hasCompletedFirstImport()) {
+      MemoryHomeWidgetService.instance.checkPendingMemorySync();
+    }
     _tabChangedEventSubscription =
         Bus.instance.on<TabChangedEvent>().listen((event) {
       _selectedTabIndex = event.selectedIndex;
@@ -184,13 +186,11 @@ class _HomeWidgetState extends State<HomeWidget> {
         }
         Future.delayed(
           delayInRefresh,
-          () => {
-            if (mounted)
-              {
-                setState(
-                  () {},
-                ),
-              },
+          () {
+            if (mounted) {
+              setState(() {});
+              MemoryHomeWidgetService.instance.checkPendingMemorySync();
+            }
           },
         );
       }

mobile/pubspec.yaml

@@ -189,7 +189,7 @@ dependencies:
   styled_text: ^8.1.0
   syncfusion_flutter_core: ^25.2.5
   syncfusion_flutter_sliders: ^25.2.5
-  synchronized: ^3.1.0
+  synchronized: ^3.3.0+3
   system_info_plus: ^0.0.6
   tuple: ^2.0.0
   ua_client_hints: ^1.4.0