feat:improve Quran data caching mechanism

- Add cache validity duration check in QuranImpl
- Implement last update timestamp functionality in QuranLocalDataSource
- Modify QuranImpl to use cache when valid and fall back to remote data
- Add SharedPreferences for storing timestamp in QuranLocalDataSource
- Create new SaveLastUpdateTimestampException
- Update quranLocalDataSourceProvider to include SharedPreferences

lib/src/data/data_source/quran/quran_local_data_source.dart

@@ -1,16 +1,19 @@
 import 'dart:developer';
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:fpdart/fpdart.dart';
 import 'package:hive_flutter/adapters.dart';
 import 'package:mawaqit/src/const/constants.dart';
 import 'package:mawaqit/src/domain/model/quran/surah_model.dart';
 
 import 'package:mawaqit/src/domain/error/quran_exceptions.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 class QuranLocalDataSource {
   final Box _surahBox;
+  final SharedPreferences _prefs;
 
-  QuranLocalDataSource(this._surahBox);
+  QuranLocalDataSource(this._surahBox, this._prefs);
 
   /// [saveSuwarByLanguage] save the list of surwars by language code
   Future<void> saveSuwarByLanguage(String languageCode, List<SurahModel> suwar) async {
@@ -69,9 +72,28 @@ class QuranLocalDataSource {
       throw CannotFindSuwarByLanguageException(e.toString());
     }
   }
+
+  Future<Option<DateTime>> getLastUpdateTimestamp(String languageCode) async {
+    try {
+      final timestamp = _prefs.getInt('${languageCode}_last_fetch');
+      return Option.fromNullable(timestamp != null ? DateTime.fromMillisecondsSinceEpoch(timestamp) : null);
+    } catch (e) {
+      log('quran: getLastUpdateTimestamp: ${e.toString()}');
+      return None();
+    }
+  }
+
+  Future<void> saveLastUpdateTimestamp(String languageCode, DateTime timestamp) async {
+    try {
+      await _prefs.setInt('${languageCode}_last_fetch', timestamp.millisecondsSinceEpoch);
+    } catch (e) {
+      throw SaveLastUpdateTimestampException(e.toString());
+    }
+  }
 }
 
 final quranLocalDataSourceProvider = FutureProvider<QuranLocalDataSource>((ref) async {
   final surahBox = await Hive.openBox(QuranConstant.kSurahBox);
-  return QuranLocalDataSource(surahBox);
+  final prefs = await SharedPreferences.getInstance();
+  return QuranLocalDataSource(surahBox, prefs);
 });

lib/src/data/repository/quran/quran_impl.dart

@@ -10,6 +10,7 @@ import 'package:mawaqit/src/data/data_source/quran/quran_remote_data_source.dart
 class QuranImpl extends QuranRepository {
   final QuranRemoteDataSource _quranRemoteDataSource;
   final QuranLocalDataSource _quranLocalDataSource;
+  final Duration _cacheValidityDuration = Duration(hours: 24);
 
   QuranImpl(
     this._quranRemoteDataSource,
@@ -28,15 +29,43 @@ class QuranImpl extends QuranRepository {
     String languageCode = 'en',
   }) async {
     try {
+      // Check if cached data exists and is still valid
+      if (await _isCacheValid(languageCode)) {
+        final cachedSuwar = await _quranLocalDataSource.getSuwarByLanguage(languageCode);
+        return cachedSuwar;
+      }
+
+      // If cache is invalid or doesn't exist, fetch from remote
       final suwar = await _quranRemoteDataSource.getSuwarByLanguage(languageCode: languageCode);
-      log('quran: QuranImpl: getSuwarByLanguage: ${suwar[0]}');
-      await _quranLocalDataSource.saveSuwarByLanguage(languageCode, suwar);
+
+      // Save the new data to cache with current timestamp
+      await _saveSuwarWithTimestamp(languageCode, suwar);
+
       return suwar;
     } on Exception catch (_) {
-      final suwar = await _quranLocalDataSource.getSuwarByLanguage(languageCode);
-      return suwar;
+      // If remote fetch fails, try to return cached data even if it's outdated
+      final cachedSuwar = await _quranLocalDataSource.getSuwarByLanguage(languageCode);
+      if (cachedSuwar.isNotEmpty) {
+        return cachedSuwar;
+      }
+      // If no cached data, rethrow the exception
+      rethrow;
     }
   }
+
+  Future<bool> _isCacheValid(String languageCode) async {
+    final lastUpdateTimestamp = await _quranLocalDataSource.getLastUpdateTimestamp(languageCode);
+    return lastUpdateTimestamp.fold(() => false, (time) {
+      final currentTime = DateTime.now();
+      final difference = currentTime.difference(time);
+      return difference < _cacheValidityDuration;
+    });
+  }
+
+  Future<void> _saveSuwarWithTimestamp(String languageCode, List<SurahModel> suwar) async {
+    await _quranLocalDataSource.saveSuwarByLanguage(languageCode, suwar);
+    await _quranLocalDataSource.saveLastUpdateTimestamp(languageCode, DateTime.now());
+  }
 }
 
 final quranRepositoryProvider = FutureProvider<QuranImpl>((ref) async {

lib/src/domain/error/quran_exceptions.dart

@@ -103,3 +103,8 @@ class CannotFindSuwarByLanguageException extends QuranException {
   CannotFindSuwarByLanguageException(String message)
       : super('Error occurred while finding suwar by language: $message', 'FIND_SUWAR_BY_LANGUAGE_ERROR');
 }
+
+class SaveLastUpdateTimestampException extends QuranException {
+  SaveLastUpdateTimestampException(String message)
+      : super('Error occurred while saving last update timestamp: $message', 'SAVE_LAST_UPDATE_TIMESTAMP_ERROR');
+}