import 'dart:convert';

import 'package:shared_preferences/shared_preferences.dart';

import '../alarm.dart';
import '../location.dart';
import '../task.dart';
import 'interfaces/alarm_repository.dart';
import 'interfaces/location_repository.dart';
import 'interfaces/task_repository.dart';

class LocalRepository
    implements TaskRepository, AlarmRepository, LocationRepository {
  static const String _tasksKey = 'tasks';
  static const String _taskOrderKey = 'taskOrder';
  static const String _alarmsKey = 'alarms';
  static const String _locationsKey = 'locations';

  SharedPreferencesWithCache? _prefs;

  Future<void> initialize() async {
    if (_prefs == null) {
      await SharedPreferencesWithCache.create(
        cacheOptions: const SharedPreferencesWithCacheOptions(
          allowList: <String>{
            _tasksKey,
            _taskOrderKey,
            _alarmsKey,
            _locationsKey,
          },
        ),
      ).then((value) => _prefs = value);
    }
  }

  Future<void> _saveTasks(List<Task> tasks) async {
    final jsonList = tasks.map<String>((e) => jsonEncode(e.toJson())).toList();
    _prefs!.setStringList(_tasksKey, jsonList);
  }

  Future<void> _saveLocations(List<Location> locations) async {
    final jsonList = locations
        .map<String>((e) => jsonEncode(e.toJson()))
        .toList();
    _prefs!.setStringList(_locationsKey, jsonList);
  }

  Future<void> _saveTaskOrder(List<String> taskOrder) async {
    final jsonList = taskOrder.map((e) => jsonEncode(e)).toList();
    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
  Future<void> createTask(Task task) async {
    final tasks = await loadTasks();
    tasks.add(task);
    return _saveTasks(tasks);
  }

  @override
  Future<void> createTaskOrderEntry(String taskOrderEntry) async {
    final taskOrder = await loadTaskOrder();
    taskOrder.add(taskOrderEntry);
    return _saveTaskOrder(taskOrder);
  }

  @override
  Future<void> createAlarm(Alarm alarm) async {
    final alarms = await loadAlarms();
    alarms.add(alarm);
    _saveAlarms(alarms);
  }

  @override
  Future<void> createLocation(Location location) async {
    final locations = await loadLocations();
    locations.add(location);
    _saveLocations(locations);
  }

  // Read

  @override
  Future<List<Task>> loadTasks() async {
    final Iterable<String> jsonList = _prefs!.getStringList(_tasksKey) ?? [];
    return jsonList.map<Task>((e) => Task.fromJson(jsonDecode(e))).toList();
  }

  @override
  Future<List<String>> loadTaskOrder() async {
    final Iterable<String> jsonList =
        _prefs!.getStringList(_taskOrderKey) ?? [];
    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();
  }

  @override
  Future<List<Location>> loadLocations() async {
    final Iterable<String> jsonList =
        _prefs!.getStringList(_locationsKey) ?? [];
    return jsonList
        .map<Location>((e) => Location.fromJson(jsonDecode(e)))
        .toList();
  }

  // Update

  @override
  Future<void> updateTask(Task task) async {
    final tasks = await loadTasks();
    tasks.remove(task);
    tasks.add(task);
    return _saveTasks(tasks);
  }

  @override
  Future<void> updateTaskOrder(List<String> taskOrder) async {
    return _saveTaskOrder(taskOrder);
  }

  @override
  Future<void> updateAlarm(Alarm alarm) async {
    final alarms = await loadAlarms();
    alarms.remove(alarm);
    alarms.add(alarm);
    _saveAlarms(alarms);
  }

  @override
  Future<void> updateLocation(Location location) async {
    final locations = await loadLocations();
    locations.remove(location);
    locations.add(location);
    _saveLocations(locations);
  }

  // Delete

  @override
  Future<void> deleteTask(Task task) async {
    final tasks = await loadTasks();
    tasks.remove(task);
    return _saveTasks(tasks);
  }

  @override
  Future<void> deleteTaskOrderEntry(String taskOrderEntry) async {
    final taskOrder = await loadTaskOrder();
    taskOrder.remove(taskOrderEntry);
    return _saveTaskOrder(taskOrder);
  }

  @override
  Future<void> deleteAlarm(Alarm alarm) async {
    final alarms = await loadAlarms();
    alarms.remove(alarm);
    _saveAlarms(alarms);
  }

  @override
  Future<void> deleteLocation(Location location) async {
    final locations = await loadLocations();
    locations.remove(location);
    _saveLocations(locations);
  }
}