import 'dart:ui';

import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:shared_preferences/shared_preferences.dart';

part 'locale_provider.g.dart';

/// Key for storing locale preference in SharedPreferences
const String _localeKey = 'app_locale';

/// Provider for locale state management
/// State is Locale? where null means "use system default"
@riverpod
class LocaleNotifier extends _$LocaleNotifier {
  @override
  Locale? build() {
    _loadLocale();
    return null; // Default: system locale
  }

  /// Load locale from SharedPreferences
  Future<void> _loadLocale() async {
    final prefs = await SharedPreferences.getInstance();
    final localeString = prefs.getString(_localeKey);

    if (localeString != null) {
      final parts = localeString.split('_');
      final locale =
          parts.length > 1 ? Locale(parts[0], parts[1]) : Locale(parts[0]);
      state = locale;
    }
  }

  /// Set locale and persist to SharedPreferences
  /// Pass null to use system default
  Future<void> setLocale(Locale? locale) async {
    state = locale;
    final prefs = await SharedPreferences.getInstance();
    if (locale == null) {
      await prefs.remove(_localeKey);
    } else {
      final localeString = locale.countryCode != null
          ? '${locale.languageCode}_${locale.countryCode}'
          : locale.languageCode;
      await prefs.setString(_localeKey, localeString);
    }
  }
}