Harden app for 24-7 offline-first operation

lib/data/local/models.dart

@@ -77,6 +77,10 @@ class AppSettings extends HiveObject {
   @HiveField(19)
   String? lastSyncDate;
 
+  // Last automatic sync attempt timestamp (ISO8601).
+  @HiveField(32)
+  String? lastAutoSyncAttemptDate;
+
   // Slideshow image paths (local)
   @HiveField(20)
   List<String> slideshowImages;
@@ -148,6 +152,7 @@ class AppSettings extends HiveObject {
     this.mainScreenDurationSec = 15,
     this.slideDurationSec = 10,
     this.lastSyncDate,
+    this.lastAutoSyncAttemptDate,
     this.slideshowImages = const [],
     this.textScaleIndex = 1,
     this.useUnsplashBackground = false,
@@ -183,6 +188,7 @@ class AppSettings extends HiveObject {
     int? mainScreenDurationSec,
     int? slideDurationSec,
     String? lastSyncDate,
+    String? lastAutoSyncAttemptDate,
     List<String>? slideshowImages,
     int? textScaleIndex,
     bool? useUnsplashBackground,
@@ -217,6 +223,8 @@ class AppSettings extends HiveObject {
       mainScreenDurationSec: mainScreenDurationSec ?? this.mainScreenDurationSec,
       slideDurationSec: slideDurationSec ?? this.slideDurationSec,
       lastSyncDate: lastSyncDate ?? this.lastSyncDate,
+      lastAutoSyncAttemptDate:
+          lastAutoSyncAttemptDate ?? this.lastAutoSyncAttemptDate,
       slideshowImages: slideshowImages ?? this.slideshowImages,
       textScaleIndex: textScaleIndex ?? this.textScaleIndex,
       useUnsplashBackground: useUnsplashBackground ?? this.useUnsplashBackground,
@@ -266,6 +274,7 @@ class AppSettingsAdapter extends TypeAdapter<AppSettings> {
       mainScreenDurationSec: fields[17] as int? ?? 15,
       slideDurationSec: fields[18] as int? ?? 10,
       lastSyncDate: fields[19] as String?,
+      lastAutoSyncAttemptDate: fields[32] as String?,
       slideshowImages: (fields[20] as List?)?.cast<String>() ?? const [],
       textScaleIndex: fields[21] as int? ?? 1,
       useUnsplashBackground: fields[22] as bool? ?? false,
@@ -284,7 +293,7 @@ class AppSettingsAdapter extends TypeAdapter<AppSettings> {
   @override
   void write(BinaryWriter writer, AppSettings obj) {
     writer
-      ..writeByte(32)
+      ..writeByte(33)
       ..writeByte(0)..write(obj.masjidName)
       ..writeByte(1)..write(obj.masjidAddress)
       ..writeByte(2)..write(obj.cityIdApi)
@@ -305,6 +314,7 @@ class AppSettingsAdapter extends TypeAdapter<AppSettings> {
       ..writeByte(17)..write(obj.mainScreenDurationSec)
       ..writeByte(18)..write(obj.slideDurationSec)
       ..writeByte(19)..write(obj.lastSyncDate)
+      ..writeByte(32)..write(obj.lastAutoSyncAttemptDate)
       ..writeByte(20)..write(obj.slideshowImages)
       ..writeByte(21)..write(obj.textScaleIndex)
       ..writeByte(22)..write(obj.useUnsplashBackground)

lib/data/services/sync_service.dart

@@ -77,16 +77,75 @@ class ScheduleCacheStatus {
 class SyncService {
   SyncService._();
   static final SyncService instance = SyncService._();
+  static const Duration _autoRefreshCooldown = Duration(hours: 12);
+
+  static Set<String> rollingWindowMonths(DateTime referenceDate) {
+    final currentMonth = DateTime(referenceDate.year, referenceDate.month, 1);
+    final nextMonth = DateTime(referenceDate.year, referenceDate.month + 1, 1);
+    return {
+      DateFormat('yyyy-MM').format(currentMonth),
+      DateFormat('yyyy-MM').format(nextMonth),
+    };
+  }
+
+  static List<String> staleScheduleKeys(
+    Iterable<String> keys,
+    DateTime referenceDate,
+  ) {
+    final allowedMonths = rollingWindowMonths(referenceDate);
+    final staleKeys = <String>[];
+
+    for (final key in keys) {
+      final parsed = DateTime.tryParse(key);
+      if (parsed == null) {
+        staleKeys.add(key);
+        continue;
+      }
+
+      final monthKey = DateFormat('yyyy-MM').format(parsed);
+      if (!allowedMonths.contains(monthKey)) {
+        staleKeys.add(key);
+      }
+    }
+
+    return staleKeys;
+  }
+
+  Future<void> _pruneScheduleCache(
+    Box<DailyPrayerSchedule> scheduleBox,
+    DateTime referenceDate,
+  ) async {
+    final staleKeys = staleScheduleKeys(
+      scheduleBox.keys.cast<String>(),
+      referenceDate,
+    );
+    if (staleKeys.isNotEmpty) {
+      await scheduleBox.deleteAll(staleKeys);
+      await scheduleBox.compact();
+    }
+  }
+
+  bool _shouldAttemptAutoRefresh({
+    required ScheduleCacheStatus status,
+    required bool hasTodayData,
+  }) {
+    return !hasTodayData || !status.hasData || status.needsRefreshSoon;
+  }
+
+  DateTime? _parseAttemptTimestamp(String? value) {
+    if (value == null || value.isEmpty) return null;
+    return DateTime.tryParse(value);
+  }
 
   /// Sync current month + next month prayer data for the configured city.
   /// Returns true on success.
-  Future<bool> syncMonthlyData() async {
+  Future<bool> syncMonthlyData({DateTime? referenceDate}) async {
     final settingsBox = Hive.box<AppSettings>(HiveBoxes.settings);
     final settings = settingsBox.get('default');
     if (settings == null) return false;
 
     final cityId = settings.cityIdApi;
-    final now = DateTime.now();
+    final now = referenceDate ?? DateTime.now();
     final currentMonth = DateFormat('yyyy-MM').format(now);
 
     // Also fetch next month for continuity
@@ -97,10 +156,13 @@ class SyncService {
     final scheduleBox = Hive.box<DailyPrayerSchedule>(HiveBoxes.prayerSchedule);
 
     var success = false;
+    var hasCurrentMonth = false;
+    var hasNextMonth = false;
 
     // Fetch current month
     final currentData = await api.getMonthlySchedule(cityId, currentMonth);
     if (currentData.isNotEmpty) {
+      hasCurrentMonth = true;
       for (final entry in currentData.entries) {
         final jadwal = entry.value;
         scheduleBox.put(
@@ -124,6 +186,7 @@ class SyncService {
     // Fetch next month
     final nextData = await api.getMonthlySchedule(cityId, nextMonth);
     if (nextData.isNotEmpty) {
+      hasNextMonth = true;
       for (final entry in nextData.entries) {
         final jadwal = entry.value;
         scheduleBox.put(
@@ -144,6 +207,9 @@ class SyncService {
     }
 
     if (success) {
+      if (hasCurrentMonth && hasNextMonth) {
+        await _pruneScheduleCache(scheduleBox, now);
+      }
       settings.lastSyncDate = DateFormat('yyyy-MM-dd HH:mm').format(now);
       await settings.save();
     }
@@ -151,6 +217,38 @@ class SyncService {
     return success;
   }
 
+  Future<AutoRefreshResult> autoRefreshIfNeeded({
+    DateTime? referenceDate,
+  }) async {
+    final settingsBox = Hive.box<AppSettings>(HiveBoxes.settings);
+    final settings = settingsBox.get('default');
+    if (settings == null) {
+      return const AutoRefreshResult.skipped('settings-missing');
+    }
+
+    final now = referenceDate ?? DateTime.now();
+    final status = getCacheStatus(now);
+    final hasTodayData = getTodaySchedule(now) != null;
+
+    if (!_shouldAttemptAutoRefresh(status: status, hasTodayData: hasTodayData)) {
+      return const AutoRefreshResult.skipped('cache-fresh');
+    }
+
+    final lastAttempt = _parseAttemptTimestamp(settings.lastAutoSyncAttemptDate);
+    if (lastAttempt != null &&
+        now.difference(lastAttempt) < _autoRefreshCooldown) {
+      return const AutoRefreshResult.skipped('cooldown');
+    }
+
+    settings.lastAutoSyncAttemptDate = now.toIso8601String();
+    await settings.save();
+
+    final synced = await syncMonthlyData(referenceDate: now);
+    return synced
+        ? const AutoRefreshResult.synced()
+        : const AutoRefreshResult.failed('sync-failed');
+  }
+
   /// Get today's prayer schedule from local Hive cache.
   DailyPrayerSchedule? getTodaySchedule([DateTime? targetDate]) {
     final scheduleBox =
@@ -169,3 +267,24 @@ class SyncService {
     );
   }
 }
+
+class AutoRefreshResult {
+  final bool attempted;
+  final bool synced;
+  final String reason;
+
+  const AutoRefreshResult._({
+    required this.attempted,
+    required this.synced,
+    required this.reason,
+  });
+
+  const AutoRefreshResult.skipped(String reason)
+      : this._(attempted: false, synced: false, reason: reason);
+
+  const AutoRefreshResult.synced()
+      : this._(attempted: true, synced: true, reason: 'synced');
+
+  const AutoRefreshResult.failed(String reason)
+      : this._(attempted: true, synced: false, reason: reason);
+}

lib/features/admin/admin_screen.dart

@@ -1628,6 +1628,17 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                       height: 180 * s,
                       width: double.infinity,
                       fit: BoxFit.cover,
+                      errorBuilder: (_, __, ___) => Container(
+                        height: 180 * s,
+                        width: double.infinity,
+                        color: SacredColors.surfaceContainerLowest,
+                        alignment: Alignment.center,
+                        child: Icon(
+                          Icons.broken_image,
+                          size: 36 * s,
+                          color: SacredColors.onSurfaceVariant,
+                        ),
+                      ),
                     ),
                   ),
                   SizedBox(height: 12 * s),
@@ -1673,8 +1684,9 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                   s: s,
                   onActivate: () async {
                     final res = await FilePicker.platform.pickFiles(type: FileType.image);
-                    if (res != null && res.files.single.path != null) {
+                    final selectedPath = res?.files.single.path;
-                      setState(() => _brandedBgImage = res.files.single.path);
+                    if (selectedPath != null && File(selectedPath).existsSync()) {
+                      setState(() => _brandedBgImage = selectedPath);
                       _queueTampilanAutoSave(
                         message: 'Foto latar otomatis tersimpan',
                       );
@@ -1683,8 +1695,10 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                   child: ElevatedButton.icon(
                     onPressed: () async {
                       final res = await FilePicker.platform.pickFiles(type: FileType.image);
-                      if (res != null && res.files.single.path != null) {
+                      final selectedPath = res?.files.single.path;
-                        setState(() => _brandedBgImage = res.files.single.path);
+                      if (selectedPath != null &&
+                          File(selectedPath).existsSync()) {
+                        setState(() => _brandedBgImage = selectedPath);
                         _queueTampilanAutoSave(
                           message: 'Foto latar otomatis tersimpan',
                         );
@@ -1720,7 +1734,9 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                     if (res != null) {
                       setState(() {
                         for (var path in res.paths) {
-                          if (path != null && !_slideshowImages.contains(path)) {
+                          if (path != null &&
+                              File(path).existsSync() &&
+                              !_slideshowImages.contains(path)) {
                             _slideshowImages.add(path);
                           }
                         }
@@ -1736,7 +1752,9 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                       if (res != null) {
                         setState(() {
                           for (var path in res.paths) {
-                            if (path != null && !_slideshowImages.contains(path)) {
+                            if (path != null &&
+                                File(path).existsSync() &&
+                                !_slideshowImages.contains(path)) {
                               _slideshowImages.add(path);
                             }
                           }
@@ -1785,6 +1803,17 @@ class _AdminScreenState extends ConsumerState<AdminScreen> {
                                 width: double.infinity,
                                 height: 120 * s,
                                 fit: BoxFit.cover,
+                                errorBuilder: (_, __, ___) => Container(
+                                  width: double.infinity,
+                                  height: 120 * s,
+                                  color: SacredColors.surfaceContainerHigh,
+                                  alignment: Alignment.center,
+                                  child: Icon(
+                                    Icons.broken_image,
+                                    size: 32 * s,
+                                    color: SacredColors.onSurfaceVariant,
+                                  ),
+                                ),
                               ),
                             ),
                             SizedBox(height: 10 * s),

lib/features/home/home_view.dart

@@ -44,12 +44,15 @@ class _HomeViewState extends ConsumerState<HomeView> {
   final List<LogicalKeyboardKey> _simulationShortcutKeys = [];
   Timer? _comboResetTimer;
   Timer? _simulationShortcutTimer;
+  Timer? _autoRefreshTimer;
+  bool _isAutoRefreshRunning = false;
 
   @override
   void initState() {
     super.initState();
     WidgetsBinding.instance.addPostFrameCallback((_) {
       _checkAutoSync();
+      _startAutoRefreshMonitor();
       if (mounted) {
         _homeFocusNode.requestFocus();
       }
@@ -60,21 +63,38 @@ class _HomeViewState extends ConsumerState<HomeView> {
   void dispose() {
     _comboResetTimer?.cancel();
     _simulationShortcutTimer?.cancel();
+    _autoRefreshTimer?.cancel();
     _homeFocusNode.dispose();
     super.dispose();
   }
 
+  void _startAutoRefreshMonitor() {
+    _autoRefreshTimer?.cancel();
+    _autoRefreshTimer = Timer.periodic(
+      const Duration(hours: 6),
+      (_) => _checkAutoSync(),
+    );
+  }
+
   Future<void> _checkAutoSync() async {
-    final schedule = ref.read(todayScheduleProvider);
+    if (_isAutoRefreshRunning || !mounted) return;
-    if (schedule == null) {
+    _isAutoRefreshRunning = true;
-      debugPrint('[AutoSync] No schedule found for today! Starting auto-sync...');
+    try {
-      final success = await SyncService.instance.syncMonthlyData();
+      final result = await SyncService.instance.autoRefreshIfNeeded();
-      if (success && mounted) {
+      if (!mounted) return;
-        debugPrint('[AutoSync] Success! Invalidating todayScheduleProvider.');
+
+      if (result.synced) {
+        debugPrint('[AutoSync] Cache refreshed successfully.');
         ref.invalidate(todayScheduleProvider);
-      } else {
+        ref.invalidate(scheduleCacheStatusProvider);
-        debugPrint('[AutoSync] Failed or data remained empty.');
+        return;
       }
+
+      if (result.attempted) {
+        debugPrint('[AutoSync] Refresh attempt failed. Staying on local cache.');
+      }
+    } finally {
+      _isAutoRefreshRunning = false;
     }
   }
 

lib/features/home/jumat_screen.dart

@@ -49,6 +49,7 @@ class JumatScreen extends ConsumerWidget {
                 fit: BoxFit.cover,
                 color: Colors.black.withValues(alpha: 0.55),
                 colorBlendMode: BlendMode.darken,
+                errorBuilder: (_, __, ___) => const UnsplashBackground(),
               ),
             )
           else

lib/features/home/main_screen.dart

@@ -53,6 +53,7 @@ class MainScreen extends ConsumerWidget {
                 fit: BoxFit.cover,
                 color: Colors.black.withValues(alpha: 0.55),
                 colorBlendMode: BlendMode.darken,
+                errorBuilder: (_, __, ___) => const UnsplashBackground(),
               ),
             )
           else

lib/features/home/unsplash_background.dart

@@ -96,6 +96,7 @@ class _UnsplashBackgroundState extends ConsumerState<UnsplashBackground> {
         // Soft opacity behind the MainScreen's dark glass vignette
         color: Colors.black.withValues(alpha: 0.5), 
         colorBlendMode: BlendMode.darken,
+        errorBuilder: (_, __, ___) => const SizedBox.shrink(),
       ),
     );
   }

lib/main.dart

@@ -1,3 +1,7 @@
+import 'dart:async';
+import 'dart:io';
+import 'dart:ui';
+
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
@@ -11,7 +15,44 @@ import 'features/home/home_view.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  FlutterError.onError = (details) {
+    FlutterError.presentError(details);
+    debugPrint('[Fatal][FlutterError] ${details.exceptionAsString()}');
+  };
+  PlatformDispatcher.instance.onError = (error, stack) {
+    debugPrint('[Fatal][PlatformDispatcher] $error');
+    debugPrintStack(stackTrace: stack);
+    return true;
+  };
+  ErrorWidget.builder = (details) {
+    return const Material(
+      color: SacredColors.background,
+      child: Center(
+        child: Padding(
+          padding: EdgeInsets.all(32),
+          child: Text(
+            'Terjadi gangguan tampilan.\nAplikasi tetap berjalan dalam mode aman.',
+            textAlign: TextAlign.center,
+            style: TextStyle(
+              color: SacredColors.onSurface,
+              fontSize: 24,
+              fontWeight: FontWeight.w700,
+            ),
+          ),
+        ),
+      ),
+    );
+  };
 
+  await runZonedGuarded(() async {
+    await _bootstrapAndRun();
+  }, (error, stack) {
+    debugPrint('[Fatal][Zone] $error');
+    debugPrintStack(stackTrace: stack);
+  });
+}
+
+Future<void> _bootstrapAndRun() async {
   // Landscape-only for TV
   await SystemChrome.setPreferredOrientations([
     DeviceOrientation.landscapeLeft,
@@ -33,6 +74,7 @@ void main() async {
   if (settingsBox.get('default') == null) {
     await settingsBox.put('default', AppSettings());
   }
+  await _sanitizeMediaSettings(settingsBox);
 
   // Initialize date formatting for Indonesian locale
   await initializeDateFormatting('id_ID');
@@ -47,6 +89,33 @@ void main() async {
   );
 }
 
+Future<void> _sanitizeMediaSettings(Box<AppSettings> settingsBox) async {
+  final settings = settingsBox.get('default');
+  if (settings == null) return;
+
+  final validSlides = settings.slideshowImages
+      .where((path) => path.trim().isNotEmpty && File(path).existsSync())
+      .toList();
+  final brandedBg = (settings.brandedBgImage != null &&
+          settings.brandedBgImage!.trim().isNotEmpty &&
+          File(settings.brandedBgImage!).existsSync())
+      ? settings.brandedBgImage
+      : null;
+
+  final needsSave =
+      validSlides.length != settings.slideshowImages.length ||
+      brandedBg != settings.brandedBgImage;
+  if (!needsSave) return;
+
+  await settingsBox.put(
+    'default',
+    settings.copyWith(
+      slideshowImages: validSlides,
+      brandedBgImage: brandedBg,
+    ),
+  );
+}
+
 class JamShalatApp extends ConsumerWidget {
   const JamShalatApp({super.key});
 

test/widget_test.dart

@@ -30,11 +30,13 @@ void main() {
         masjidName: 'Masjid Raya',
         cityIdApi: '1301',
         iqomahDzuhur: 12,
+        lastAutoSyncAttemptDate: '2026-03-31T09:00:00.000',
       );
 
       expect(updated.masjidName, 'Masjid Raya');
       expect(updated.cityIdApi, '1301');
       expect(updated.iqomahDzuhur, 12);
+      expect(updated.lastAutoSyncAttemptDate, '2026-03-31T09:00:00.000');
       expect(updated.masjidAddress, settings.masjidAddress);
       expect(updated.runningTexts, settings.runningTexts);
     });
@@ -94,5 +96,25 @@ void main() {
       expect(status.cachedDays, 2);
       expect(status.daysUntilRefresh, 31);
     });
+
+    test('rolling window stale key helper keeps only current and next month', () {
+      final staleKeys = SyncService.staleScheduleKeys(
+        [
+          '2026-02-28',
+          '2026-03-01',
+          '2026-04-30',
+          '2026-05-01',
+          'invalid-key',
+        ],
+        DateTime(2026, 3, 30),
+      );
+
+      expect(
+        staleKeys,
+        containsAll(<String>['2026-02-28', '2026-05-01', 'invalid-key']),
+      );
+      expect(staleKeys, isNot(contains('2026-03-01')));
+      expect(staleKeys, isNot(contains('2026-04-30')));
+    });
   });
 }