import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:intl/intl.dart';
import 'package:shared_preferences/src/shared_preferences_legacy.dart';
import 'package:simplecloudnotifier/state/globals.dart';

enum AppSettingsDateFormat {
  ISO(displayStr: 'ISO (yyyy-MM-dd)', key: 'ISO'),
  German(displayStr: 'German (dd.MM.yyyy)', key: 'German'),
  US(displayStr: 'US (MM/dd/yyyy)', key: 'US');

  const AppSettingsDateFormat({required this.displayStr, required this.key});

  final String displayStr;
  final String key;

  @override
  toString() => displayStr;

  DateFormat dateFormat() {
    switch (this) {
      case AppSettingsDateFormat.ISO:
        return DateFormat('yyyy-MM-dd HH:mm');
      case AppSettingsDateFormat.German:
        return DateFormat('dd.MM.yyyy HH:mm');
      case AppSettingsDateFormat.US:
        return DateFormat('MM/dd/yyyy HH:mm');
    }
  }

  static AppSettingsDateFormat? parse(String? string) {
    if (string == null) return null;
    return values.firstWhere((e) => e.key == string, orElse: null);
  }
}

class AppSettings extends ChangeNotifier {
  bool groupNotifications = true;
  int messagePageSize = 128;
  bool devMode = false;
  bool showDebugButton = false;
  bool backgroundRefreshMessageListOnPop = false;
  bool alwaysBackgroundRefreshMessageListOnLifecycleResume = true;
  AppSettingsDateFormat dateFormat = AppSettingsDateFormat.ISO;
  int messagePreviewLength = 3;

  AppNotificationSettings notification0 = AppNotificationSettings();
  AppNotificationSettings notification1 = AppNotificationSettings();
  AppNotificationSettings notification2 = AppNotificationSettings();

  static AppSettings? _singleton = AppSettings._internal();

  factory AppSettings() {
    return _singleton ?? (_singleton = AppSettings._internal());
  }

  AppSettings._internal() {
    load();
  }

  void reset() {
    groupNotifications = true;
    messagePageSize = 128;
    devMode = false;
    showDebugButton = false;
    backgroundRefreshMessageListOnPop = false;
    alwaysBackgroundRefreshMessageListOnLifecycleResume = true;
    dateFormat = AppSettingsDateFormat.ISO;
    messagePreviewLength = 3;

    notification0 = AppNotificationSettings();
    notification1 = AppNotificationSettings();
    notification2 = AppNotificationSettings();

    notifyListeners();
  }

  void load() {
    groupNotifications = Globals().sharedPrefs.getBool('settings.groupNotifications') ?? groupNotifications;
    messagePageSize = Globals().sharedPrefs.getInt('settings.messagePageSize') ?? messagePageSize;
    devMode = Globals().sharedPrefs.getBool('settings.devMode') ?? devMode;
    showDebugButton = Globals().sharedPrefs.getBool('settings.showDebugButton') ?? showDebugButton;
    backgroundRefreshMessageListOnPop = Globals().sharedPrefs.getBool('settings.backgroundRefreshMessageListOnPop') ?? backgroundRefreshMessageListOnPop;
    alwaysBackgroundRefreshMessageListOnLifecycleResume = Globals().sharedPrefs.getBool('settings.alwaysBackgroundRefreshMessageListOnLifecycleResume') ?? alwaysBackgroundRefreshMessageListOnLifecycleResume;
    dateFormat = AppSettingsDateFormat.parse(Globals().sharedPrefs.getString('settings.dateFormat')) ?? dateFormat;
    messagePreviewLength = Globals().sharedPrefs.getInt('settings.messagePreviewLength') ?? messagePreviewLength;

    notification0 = AppNotificationSettings.load(Globals().sharedPrefs, 'settings.notification0');
    notification1 = AppNotificationSettings.load(Globals().sharedPrefs, 'settings.notification1');
    notification2 = AppNotificationSettings.load(Globals().sharedPrefs, 'settings.notification2');
  }

  Future<void> save() async {
    await Globals().sharedPrefs.setBool('settings.groupNotifications', groupNotifications);
    await Globals().sharedPrefs.setInt('settings.messagePageSize', messagePageSize);
    await Globals().sharedPrefs.setBool('settings.devMode', devMode);
    await Globals().sharedPrefs.setBool('settings.showDebugButton', showDebugButton);
    await Globals().sharedPrefs.setBool('settings.backgroundRefreshMessageListOnPop', backgroundRefreshMessageListOnPop);
    await Globals().sharedPrefs.setBool('settings.alwaysBackgroundRefreshMessageListOnLifecycleResume', alwaysBackgroundRefreshMessageListOnLifecycleResume);
    await Globals().sharedPrefs.setString('settings.dateFormat', dateFormat.key);
    await Globals().sharedPrefs.setInt('settings.messagePreviewLength', messagePreviewLength);

    await notification0.save(Globals().sharedPrefs, 'settings.notification0');
    await notification1.save(Globals().sharedPrefs, 'settings.notification1');
    await notification2.save(Globals().sharedPrefs, 'settings.notification2');
  }

  void update(void Function(AppSettings p) fn) {
    fn(this);
    save();
    notifyListeners();
  }

  void updateNotification(int prio, AppNotificationSettings Function(AppNotificationSettings p) fn) {
    if (prio == 0) {
      notification0 = fn(notification0);
    } else if (prio == 1) {
      notification1 = fn(notification1);
    } else if (prio == 2) {
      notification2 = fn(notification2);
    }

    save();
    notifyListeners();
  }

  AppNotificationSettings getNotificationSettings(int? prio) {
    if (prio != null && prio == 0) {
      return notification0;
    } else if (prio != null && prio == 1) {
      return notification1;
    } else if (prio != null && prio == 2) {
      return notification2;
    } else {
      return AppNotificationSettings();
    }
  }
}

class AppNotificationSettings {
  // Immutable
  AppNotificationSettings({
    this.enableLights = false,
    this.enableVibration = true,
    this.playSound = true,
    this.sound = null,
    this.silent = false,
    this.timeoutAfter = null,
  });

  final bool enableLights;
  final bool enableVibration;
  final bool playSound;
  final String? sound;
  final bool silent;
  final int? timeoutAfter;

  Future<void> save(SharedPreferences sharedPrefs, String prefix) async {
    await Globals().sharedPrefs.setBool('${prefix}.enableLights', enableLights);
    await Globals().sharedPrefs.setBool('${prefix}.enableVibration', enableVibration);
    await Globals().sharedPrefs.setBool('${prefix}.playSound', playSound);
    await Globals().sharedPrefs.setString('${prefix}.sound', _encode(sound));
    await Globals().sharedPrefs.setBool('${prefix}.silent', silent);
    await Globals().sharedPrefs.setString('${prefix}.timeoutAfter', _encode(timeoutAfter));
  }

  UriAndroidNotificationSound? soundURI() {
    return (sound != null) ? UriAndroidNotificationSound(sound!) : null;
  }

  AppNotificationSettings withEnableLights(bool v) => AppNotificationSettings(enableLights: v, enableVibration: enableVibration, playSound: playSound, sound: sound, silent: silent, timeoutAfter: timeoutAfter);
  AppNotificationSettings withEnableVibration(bool v) => AppNotificationSettings(enableLights: enableLights, enableVibration: v, playSound: playSound, sound: sound, silent: silent, timeoutAfter: timeoutAfter);
  AppNotificationSettings withPlaySound(bool v) => AppNotificationSettings(enableLights: enableLights, enableVibration: enableVibration, playSound: v, sound: sound, silent: silent, timeoutAfter: timeoutAfter);
  AppNotificationSettings withSound(String? v) => AppNotificationSettings(enableLights: enableLights, enableVibration: enableVibration, playSound: playSound, sound: v, silent: silent, timeoutAfter: timeoutAfter);
  AppNotificationSettings withSilent(bool v) => AppNotificationSettings(enableLights: enableLights, enableVibration: enableVibration, playSound: playSound, sound: sound, silent: v, timeoutAfter: timeoutAfter);
  AppNotificationSettings withTimeoutAfter(int? v) => AppNotificationSettings(enableLights: enableLights, enableVibration: enableVibration, playSound: playSound, sound: sound, silent: silent, timeoutAfter: v);

  static AppNotificationSettings load(SharedPreferences prefs, String prefix) {
    final def = AppNotificationSettings();

    final enableLights = prefs.getBool('${prefix}.enableLights') ?? def.enableLights;
    final enableVibration = prefs.getBool('${prefix}.enableVibration') ?? def.enableVibration;
    final playSound = prefs.getBool('${prefix}.playSound') ?? def.playSound;
    final sound = _decode(prefs.getString('${prefix}.sound'), def.sound);
    final silent = prefs.getBool('${prefix}.silent') ?? def.silent;
    final timeoutAfter = _decode(prefs.getString('${prefix}.timeoutAfter'), def.timeoutAfter);

    return AppNotificationSettings(
      enableLights: enableLights,
      enableVibration: enableVibration,
      playSound: playSound,
      sound: sound,
      silent: silent,
      timeoutAfter: timeoutAfter,
    );
  }
}

String _encode<T>(T v) {
  return JsonEncoder().convert(v);
}

T _decode<T>(String? v, T fallback) {
  if (v == null) return fallback;
  try {
    return JsonDecoder().convert(v) as T;
  } catch (_) {
    return fallback;
  }
}