added alarm handling

lib/model/repositories/local_repository.dart

@@ -2,12 +2,16 @@ import 'dart:convert';
 
 import 'package:shared_preferences/shared_preferences.dart';
 
+import '../alarm.dart';
 import '../task.dart';
+import 'interfaces/alarm_repository.dart';
 import 'interfaces/task_repository.dart';
 
-class LocalRepository implements TaskRepository {
+class LocalRepository implements TaskRepository, AlarmRepository {
   static const String _tasksKey = 'tasks';
   static const String _taskOrderKey = 'taskOrder';
+  static const String _alarmsKey = 'alarms';
+
   SharedPreferencesWithCache? _prefs;
 
   Future<void> initialize() async {
@@ -30,6 +34,11 @@ class LocalRepository implements TaskRepository {
     return _prefs!.setStringList(_taskOrderKey, jsonList);
   }
 
+  Future<void> _saveAlarms(List<Alarm> alarms) async {
+    final jsonList = alarms.map<String>((e) => jsonEncode(e.toJson())).toList();
+    return _prefs!.setStringList(_alarmsKey, jsonList);
+  }
+
   // Create
 
   @override
@@ -46,6 +55,13 @@ class LocalRepository implements TaskRepository {
     return _saveTaskOrder(taskOrder);
   }
 
+  @override
+  Future<void> createAlarm(Alarm alarm) async {
+    final alarms = await loadAlarms();
+    alarms.add(alarm);
+    _saveAlarms(alarms);
+  }
+
   // Read
 
   @override
@@ -61,6 +77,12 @@ class LocalRepository implements TaskRepository {
     return jsonList.map<String>((e) => jsonDecode(e)).toList();
   }
 
+  @override
+  Future<List<Alarm>> loadAlarms() async {
+    final Iterable<String> jsonList = _prefs!.getStringList(_alarmsKey) ?? [];
+    return jsonList.map<Alarm>((e) => Alarm.fromJson(jsonDecode(e))).toList();
+  }
+
   // Update
 
   @override
@@ -76,6 +98,14 @@ class LocalRepository implements TaskRepository {
     return _saveTaskOrder(taskOrder);
   }
 
+  @override
+  Future<void> updateAlarm(Alarm alarm) async {
+    final alarms = await loadAlarms();
+    alarms.remove(alarm);
+    alarms.add(alarm);
+    _saveAlarms(alarms);
+  }
+
   // Delete
 
   @override
@@ -91,4 +121,11 @@ class LocalRepository implements TaskRepository {
     taskOrder.remove(taskOrderEntry);
     return _saveTaskOrder(taskOrder);
   }
+
+  @override
+  Future<void> deleteAlarm(Alarm alarm) async {
+    final alarms = await loadAlarms();
+    alarms.remove(alarm);
+    _saveAlarms(alarms);
+  }
 }