import 'dart:async';
import 'dart:convert';
import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:openfoodfacts/openfoodfacts.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:smooth_app/data_models/product_preferences.dart';
import 'package:smooth_app/pages/onboarding/onboarding_flow_navigator.dart';
import 'package:smooth_app/pages/preferences/user_preferences_dev_mode.dart';
import 'package:smooth_app/pages/product/product_page/footer/new_product_footer.dart';
import 'package:smooth_app/themes/color_schemes.dart';
import 'package:smooth_app/themes/theme_provider.dart';

part 'package:smooth_app/data_models/preferences/migration/user_preferences_migration.dart';

/// User choice regarding the picture source.
enum UserPictureSource {
  /// Always select between Gallery and Camera
  SELECT('S'),

  /// Always use Gallery
  GALLERY('G'),

  /// Always use Camera
  CAMERA('C');

  const UserPictureSource(this.tag);

  final String tag;

  static UserPictureSource get defaultValue => UserPictureSource.SELECT;

  static UserPictureSource fromString(final String tag) => UserPictureSource
      .values
      .firstWhere((final UserPictureSource source) => source.tag == tag);
}

class UserPreferences extends ChangeNotifier {
  UserPreferences._shared(final SharedPreferences sharedPreferences)
    : _sharedPreferences = sharedPreferences {
    onCrashReportingChanged = ValueNotifier<bool>(crashReports);
    onAnalyticsChanged = ValueNotifier<bool>(userTracking);
    _incrementAppLaunches();
  }

  /// Singleton
  static UserPreferences? _instance;
  final SharedPreferences _sharedPreferences;

  static Future<UserPreferences> getUserPreferences() async {
    if (_instance == null) {
      final SharedPreferences preferences =
          await SharedPreferences.getInstance();
      _instance = UserPreferences._shared(preferences);
    }

    return _instance!;
  }

  /// Once we initialized with main.dart, we don't need the "async".
  static UserPreferences getUserPreferencesSync() => _instance!;

  late ValueNotifier<bool> onCrashReportingChanged;
  late ValueNotifier<bool> onAnalyticsChanged;

  /// Whether the preferences are empty or not
  static const String _TAG_INIT = 'init';

  /// The current version of preferences
  static const String _TAG_VERSION = 'prefs_version';
  static const int _PREFS_CURRENT_VERSION = 3;
  static const String _TAG_APP_LAUNCHES = 'appLaunches';
  static const String _TAG_PREFIX_IMPORTANCE = 'IMPORTANCE_AS_STRING';
  static const String _TAG_CURRENT_THEME_MODE = 'currentThemeMode';
  static const String _TAG_CURRENT_COLOR_SCHEME = 'currentColorScheme';
  static const String _TAG_CURRENT_CONTRAST_MODE = 'contrastMode';
  static const String _TAG_USER_COUNTRY_CODE = 'userCountry';
  static const String _TAG_USER_COUNTRY_CODE_LAST_UPDATE =
      'userCountryLastUpdate';
  static const String _TAG_USER_CURRENCY_CODE = 'userCurrency';
  static const String _TAG_LAST_VISITED_ONBOARDING_PAGE =
      'lastVisitedOnboardingPage';
  static const String _TAG_PREFIX_FLAG = 'FLAG_PREFIX_';
  static const String _TAG_DEV_MODE = 'devMode';
  static const String _TAG_USER_TRACKING = 'user_tracking';
  static const String _TAG_CRASH_REPORTS = 'crash_reports';
  static const String _TAG_PRICES_FEEDBACK_FORM = 'prices_feedback_form';
  static const String _TAG_EXCLUDED_ATTRIBUTE_IDS = 'excluded_attributes';
  static const String _TAG_UNIQUE_RANDOM = '_unique_random';
  static const String _TAG_LAZY_COUNT_PREFIX = '_lazy_count_prefix';
  static const String _TAG_LATEST_PRODUCT_TYPE = '_latest_product_type';
  static const String _TAG_SEARCH_SHOW_PRODUCT_TYPE_FILTER =
      '_search_show_product_type_filter';
  static const String _TAG_PRODUCT_PAGE_ACTIONS = '_product_page_actions';
  static const String _TAG_LANGUAGES_USAGE = '_languages_usage';
  static const String _TAG_PRODUCT_PAGE_TABS = '_product_page_tabs';
  static const String _TAG_READY_FOR_PRICE_TAG_VALIDATION =
      'ready_for_price_tag_validation';

  /// Camera preferences

  // Use the flash/torch with the camera
  static const String _TAG_USE_FLASH_WITH_CAMERA = 'enable_flash_with_camera';

  // Play sound when decoding a barcode
  static const String _TAG_PLAY_CAMERA_SCAN_SOUND = 'camera_scan_sound';

  /// Vibrations / haptic feedback
  static const String _TAG_HAPTIC_FEEDBACK_IN_APP = 'haptic_feedback_enabled';

  /// Price privacy warning
  static const String TAG_PRICE_PRIVACY_WARNING = 'price_privacy_warning';

  /// Attribute group that is not collapsed
  static const String _TAG_ACTIVE_ATTRIBUTE_GROUP = 'activeAttributeGroup';

  /// User picture source
  static const String _TAG_USER_PICTURE_SOURCE = 'userPictureSource';

  /// If the in-app review was asked at least one time (false by default)
  static const String _TAG_IN_APP_REVIEW_ALREADY_DISPLAYED =
      'inAppReviewAlreadyAsked';

  static const String _TAG_NUMBER_OF_SCANS = 'numberOfScans';

  /// User knowledge panel order
  static const String _TAG_USER_KNOWLEDGE_PANEL_ORDER =
      'userKnowledgePanelOrder';

  /// Tagline feed (news displayed / clicked)
  static const String _TAG_TAGLINE_FEED_NEWS_DISPLAYED =
      'taglineFeedNewsDisplayed';
  static const String _TAG_TAGLINE_FEED_NEWS_CLICKED = 'taglineFeedNewsClicked';

  /// Info messages
  static const String _TAG_SHOW_BANNER_INPUT_PRODUCT_NAME =
      'bannerInputProductName';

  Future<void> init(final ProductPreferences productPreferences) async {
    await _onMigrate();

    if (_sharedPreferences.getBool(_TAG_INIT) != null) {
      return;
    }
    await productPreferences.resetImportances();
    await _sharedPreferences.setBool(_TAG_INIT, true);
  }

  /// Allow to migrate between versions
  Future<void> _onMigrate() async {
    await UserPreferencesMigrationTool.onUpgrade(
      this,
      _sharedPreferences.getInt(_TAG_VERSION),
      _PREFS_CURRENT_VERSION,
    );

    await _sharedPreferences.setInt(
      _TAG_VERSION,
      UserPreferences._PREFS_CURRENT_VERSION,
    );
  }

  int get appLaunches => _sharedPreferences.getInt(_TAG_APP_LAUNCHES) ?? 0;

  Future<void> _incrementAppLaunches() async {
    await _sharedPreferences.setInt(_TAG_APP_LAUNCHES, appLaunches + 1);
    // No need to call notifyListeners here
  }

  String _getImportanceTag(final String variable) =>
      _TAG_PREFIX_IMPORTANCE + variable;

  Future<void> setImportance(
    final String attributeId,
    final String importanceId,
  ) async {
    await _sharedPreferences.setString(
      _getImportanceTag(attributeId),
      importanceId,
    );
    notifyListeners();
  }

  String getImportance(final String attributeId) =>
      _sharedPreferences.getString(_getImportanceTag(attributeId)) ??
      PreferenceImportance.ID_NOT_IMPORTANT;

  Future<void> setTheme(final String theme) async {
    await _sharedPreferences.setString(_TAG_CURRENT_THEME_MODE, theme);
    notifyListeners();
  }

  Future<void> setColorScheme(final String color) async {
    await _sharedPreferences.setString(_TAG_CURRENT_COLOR_SCHEME, color);
    notifyListeners();
  }

  Future<void> setContrastScheme(final String contrastLevel) async {
    await _sharedPreferences.setString(
      _TAG_CURRENT_CONTRAST_MODE,
      contrastLevel,
    );
    notifyListeners();
  }

  String _getLazyCountTag(final String tag) => '$_TAG_LAZY_COUNT_PREFIX$tag';

  Future<void> setLazyCount(
    final int value,
    final String suffixTag, {
    required final bool notify,
  }) async {
    final int? oldValue = getLazyCount(suffixTag);
    if (value == oldValue) {
      return;
    }
    await _sharedPreferences.setInt(_getLazyCountTag(suffixTag), value);
    if (notify) {
      notifyListeners();
    }
  }

  int? getLazyCount(final String suffixTag) =>
      _sharedPreferences.getInt(_getLazyCountTag(suffixTag));

  Future<void> setUserTracking(final bool state) async {
    await _sharedPreferences.setBool(_TAG_USER_TRACKING, state);
    onAnalyticsChanged.value = state;
    notifyListeners();
  }

  bool get userTracking =>
      _sharedPreferences.getBool(_TAG_USER_TRACKING) ?? false;

  /// Returns a huge random value that will be computed just once.
  Future<int> getUniqueRandom() async {
    const String tag = _TAG_UNIQUE_RANDOM;
    int? result = _sharedPreferences.getInt(tag);
    if (result != null) {
      return result;
    }
    result = math.Random().nextInt(1 << 32);
    await _sharedPreferences.setInt(tag, result);
    return result;
  }

  Future<void> setCrashReports(final bool state) async {
    await _sharedPreferences.setBool(_TAG_CRASH_REPORTS, state);
    onCrashReportingChanged.value = state;
    notifyListeners();
  }

  bool get crashReports =>
      _sharedPreferences.getBool(_TAG_CRASH_REPORTS) ?? false;

  Future<void> markPricesFeedbackFormAsCompleted() async {
    await _sharedPreferences.setBool(_TAG_PRICES_FEEDBACK_FORM, false);
    notifyListeners();
  }

  bool get shouldShowPricesFeedbackForm =>
      _sharedPreferences.getBool(_TAG_PRICES_FEEDBACK_FORM) ?? true;

  Future<void> setReadyForPriceTagValidation(final bool state) async =>
      _sharedPreferences.setBool(_TAG_READY_FOR_PRICE_TAG_VALIDATION, state);

  bool get readyForPriceTagValidation =>
      _sharedPreferences.getBool(_TAG_READY_FOR_PRICE_TAG_VALIDATION) ?? false;

  String get currentTheme =>
      _sharedPreferences.getString(_TAG_CURRENT_THEME_MODE) ??
      THEME_SYSTEM_DEFAULT;

  String get currentColor =>
      _sharedPreferences.getString(_TAG_CURRENT_COLOR_SCHEME) ??
      COLOR_DEFAULT_NAME;

  String get currentContrastLevel =>
      _sharedPreferences.getString(_TAG_CURRENT_CONTRAST_MODE) ??
      CONTRAST_MEDIUM;

  /// Please use [ProductQuery.setCountry] as interface
  Future<void> setUserCountryCode(final String countryCode) async {
    await _sharedPreferences.setString(_TAG_USER_COUNTRY_CODE, countryCode);
    await _sharedPreferences.setInt(
      _TAG_USER_COUNTRY_CODE_LAST_UPDATE,
      DateTime.now().millisecondsSinceEpoch,
    );
    notifyListeners();
  }

  String? get userCountryCode =>
      _sharedPreferences.getString(_TAG_USER_COUNTRY_CODE);

  Future<void> setUserCurrencyCode(final String code) async {
    await _sharedPreferences.setString(_TAG_USER_CURRENCY_CODE, code);
    notifyListeners();
  }

  String? get userCurrencyCode =>
      _sharedPreferences.getString(_TAG_USER_CURRENCY_CODE);

  Future<void> setLastVisitedOnboardingPage(final OnboardingPage page) async {
    await _sharedPreferences.setInt(
      _TAG_LAST_VISITED_ONBOARDING_PAGE,
      page.index,
    );
    notifyListeners();
  }

  Future<void> resetOnboarding() async {
    await setLastVisitedOnboardingPage(OnboardingPage.NOT_STARTED);
    // for tests with a fresh null country
    await _sharedPreferences.remove(_TAG_USER_COUNTRY_CODE);
    await _sharedPreferences.remove(_TAG_USER_CURRENCY_CODE);
    notifyListeners();
  }

  OnboardingPage get lastVisitedOnboardingPage {
    final int? pageIndex = _sharedPreferences.getInt(
      _TAG_LAST_VISITED_ONBOARDING_PAGE,
    );
    return pageIndex == null
        ? OnboardingPage.NOT_STARTED
        : OnboardingPage.values[math.min(
            pageIndex,
            OnboardingPage.values.length - 1,
          )];
  }

  Future<void> incrementScanCount() async {
    await _sharedPreferences.setInt(_TAG_NUMBER_OF_SCANS, numberOfScans + 1);
    notifyListeners();
  }

  int get numberOfScans => _sharedPreferences.getInt(_TAG_NUMBER_OF_SCANS) ?? 0;

  Future<void> markInAppReviewAsShown() async {
    await _sharedPreferences.setBool(
      _TAG_IN_APP_REVIEW_ALREADY_DISPLAYED,
      true,
    );
    notifyListeners();
  }

  bool get inAppReviewAlreadyAsked =>
      _sharedPreferences.getBool(_TAG_IN_APP_REVIEW_ALREADY_DISPLAYED) ?? false;

  /// Please use [ProductQuery.setLanguage] as interface
  Future<void> setAppLanguageCode(String? languageCode) async {
    if (languageCode == null) {
      await _sharedPreferences.remove(
        UserPreferencesDevMode.userPreferencesAppLanguageCode,
      );
    } else {
      await setDevModeString(
        UserPreferencesDevMode.userPreferencesAppLanguageCode,
        languageCode,
      );
    }
    notifyListeners();
  }

  /// Please use [ProductQuery.getLanguage] as interface
  String? get appLanguageCode =>
      getDevModeString(UserPreferencesDevMode.userPreferencesAppLanguageCode);

  String _getFlagTag(final String key) => _TAG_PREFIX_FLAG + key;

  Future<void> setFlag(final String key, final bool? value) async {
    value == null
        ? await _sharedPreferences.remove(_getFlagTag(key))
        : await _sharedPreferences.setBool(_getFlagTag(key), value);
    notifyListeners();
  }

  bool? getFlag(final String key) =>
      _sharedPreferences.getBool(_getFlagTag(key));

  List<String> getExcludedAttributeIds() =>
      _sharedPreferences.getStringList(_TAG_EXCLUDED_ATTRIBUTE_IDS) ??
      <String>[];

  Future<void> setExcludedAttributeIds(final List<String> value) async {
    await _sharedPreferences.setStringList(_TAG_EXCLUDED_ATTRIBUTE_IDS, value);
    notifyListeners();
  }

  bool get useFlashWithCamera =>
      _sharedPreferences.getBool(_TAG_USE_FLASH_WITH_CAMERA) ?? false;

  Future<void> setUseFlashWithCamera(final bool useFlash) async {
    await _sharedPreferences.setBool(_TAG_USE_FLASH_WITH_CAMERA, useFlash);
    notifyListeners();
  }

  Future<void> setPlayCameraSound(bool playSound) async {
    await _sharedPreferences.setBool(_TAG_PLAY_CAMERA_SCAN_SOUND, playSound);
    notifyListeners();
  }

  bool get playCameraSound =>
      _sharedPreferences.getBool(_TAG_PLAY_CAMERA_SCAN_SOUND) ?? false;

  Future<void> setHapticFeedbackEnabled(bool enabled) async {
    await _sharedPreferences.setBool(_TAG_HAPTIC_FEEDBACK_IN_APP, enabled);
    notifyListeners();
  }

  bool get hapticFeedbackEnabled =>
      _sharedPreferences.getBool(_TAG_HAPTIC_FEEDBACK_IN_APP) ?? true;

  Future<void> setDevMode(final int value) async {
    await _sharedPreferences.setInt(_TAG_DEV_MODE, value);
    notifyListeners();
  }

  int get devMode => _sharedPreferences.getInt(_TAG_DEV_MODE) ?? 0;

  Future<void> setDevModeString(final String tag, final String value) async {
    await _sharedPreferences.setString(tag, value);
    notifyListeners();
  }

  String? getDevModeString(final String tag) =>
      _sharedPreferences.getString(tag);

  Future<void> setActiveAttributeGroup(final String value) async {
    await _sharedPreferences.setString(_TAG_ACTIVE_ATTRIBUTE_GROUP, value);
    notifyListeners();
  }

  String get activeAttributeGroup =>
      _sharedPreferences.getString(_TAG_ACTIVE_ATTRIBUTE_GROUP) ??
      AttributeGroup.ATTRIBUTE_GROUP_NUTRITIONAL_QUALITY;

  UserPictureSource get userPictureSource => UserPictureSource.fromString(
    _sharedPreferences.getString(_TAG_USER_PICTURE_SOURCE) ??
        UserPictureSource.defaultValue.tag,
  );

  Future<void> setUserPictureSource(final UserPictureSource source) async {
    await _sharedPreferences.setString(_TAG_USER_PICTURE_SOURCE, source.tag);
    notifyListeners();
  }

  List<String> get userKnowledgePanelOrder =>
      _sharedPreferences.getStringList(_TAG_USER_KNOWLEDGE_PANEL_ORDER) ??
      <String>[];

  Future<void> setUserKnowledgePanelOrder(final List<String> source) async {
    await _sharedPreferences.setStringList(
      _TAG_USER_KNOWLEDGE_PANEL_ORDER,
      source,
    );
    notifyListeners();
  }

  List<String> get taglineFeedDisplayedNews =>
      _sharedPreferences.getStringList(_TAG_TAGLINE_FEED_NEWS_DISPLAYED) ??
      <String>[];

  List<String> get taglineFeedClickedNews =>
      _sharedPreferences.getStringList(_TAG_TAGLINE_FEED_NEWS_CLICKED) ??
      <String>[];

  // This method voluntarily does not notify listeners (not needed)
  Future<void> taglineFeedMarkNewsAsDisplayed(final String ids) async {
    final List<String> displayedNews = taglineFeedDisplayedNews;
    final List<String> clickedNews = taglineFeedClickedNews;

    if (!displayedNews.contains(ids)) {
      displayedNews.add(ids);
      _sharedPreferences.setStringList(
        _TAG_TAGLINE_FEED_NEWS_DISPLAYED,
        displayedNews,
      );
    }

    if (clickedNews.contains(ids)) {
      clickedNews.remove(ids);
      _sharedPreferences.setStringList(
        _TAG_TAGLINE_FEED_NEWS_CLICKED,
        clickedNews,
      );
    }
  }

  // This method voluntarily does not notify listeners (not needed)
  Future<void> taglineFeedMarkNewsAsClicked(final String ids) async {
    final List<String> displayedNews = taglineFeedDisplayedNews;
    final List<String> clickedNews = taglineFeedClickedNews;

    if (displayedNews.contains(ids)) {
      displayedNews.remove(ids);
      _sharedPreferences.setStringList(
        _TAG_TAGLINE_FEED_NEWS_DISPLAYED,
        displayedNews,
      );
    }

    if (!clickedNews.contains(ids)) {
      clickedNews.add(ids);
      _sharedPreferences.setStringList(
        _TAG_TAGLINE_FEED_NEWS_CLICKED,
        clickedNews,
      );
    }
  }

  bool showInputProductNameBanner() =>
      _sharedPreferences.getBool(_TAG_SHOW_BANNER_INPUT_PRODUCT_NAME) ?? true;

  Future<void> hideInputProductNameBanner() async {
    await _sharedPreferences.setBool(
      _TAG_SHOW_BANNER_INPUT_PRODUCT_NAME,
      false,
    );
    notifyListeners();
  }

  ProductType get latestProductType =>
      ProductType.fromOffTag(
        _sharedPreferences.getString(_TAG_LATEST_PRODUCT_TYPE),
      ) ??
      ProductType.food;

  set latestProductType(final ProductType value) => unawaited(
    _sharedPreferences.setString(_TAG_LATEST_PRODUCT_TYPE, value.offTag),
  );

  Future<void> setSearchProductTypeFilter(final bool visible) async {
    await _sharedPreferences.setBool(
      _TAG_SEARCH_SHOW_PRODUCT_TYPE_FILTER,
      visible,
    );
    notifyListeners();
  }

  bool get searchProductTypeFilterVisible =>
      _sharedPreferences.getBool(_TAG_SEARCH_SHOW_PRODUCT_TYPE_FILTER) ?? false;

  List<ProductFooterActionBar> get productPageActions {
    final List<String>? actions = _sharedPreferences.getStringList(
      _TAG_PRODUCT_PAGE_ACTIONS,
    );

    if (actions == null) {
      return ProductFooterActionBar.defaultOrder();
    }

    return actions
        .map((String action) => ProductFooterActionBar.fromKey(action))
        .toList(growable: false);
  }

  Future<void> setProductPageActions(
    final Iterable<ProductFooterActionBar> value,
  ) async {
    assert(!value.contains(ProductFooterActionBar.settings));
    await _sharedPreferences.setStringList(
      _TAG_PRODUCT_PAGE_ACTIONS,
      value
          .map((ProductFooterActionBar action) => action.key)
          .toList(growable: false),
    );
    notifyListeners();
  }

  void increaseLanguageUsage(final OpenFoodFactsLanguage language) {
    final String? usage = _sharedPreferences.getString(_TAG_LANGUAGES_USAGE);
    final Map<String, int> languages;
    if (usage == null || usage.isEmpty) {
      languages = <String, int>{};
    } else {
      languages = Map<String, int>.from(jsonDecode(usage));
    }

    languages[language.code] = (languages[language.code] ?? 0) + 1;
    unawaited(
      _sharedPreferences.setString(_TAG_LANGUAGES_USAGE, jsonEncode(languages)),
    );
  }

  Map<String, int> get languagesUsage {
    final String? usage = _sharedPreferences.getString(_TAG_LANGUAGES_USAGE);
    if (usage == null || usage.isEmpty) {
      return <String, int>{};
    }
    return Map<String, int>.from(jsonDecode(usage));
  }

  List<String> get productPageTabs =>
      _sharedPreferences.getStringList(_TAG_PRODUCT_PAGE_TABS) ?? <String>[];
  Future<void> setProductPageTabs(final List<String> value) async {
    await _sharedPreferences.setStringList(_TAG_PRODUCT_PAGE_TABS, value);
    notifyListeners();
  }
}