import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

/// Provider de thème — light / dark avec persistance
class ThemeProvider extends ChangeNotifier {
  static const String _key = 'uf_theme_mode';

  ThemeMode _mode;

  ThemeProvider({ThemeMode initial = ThemeMode.system}) : _mode = initial;

  ThemeMode get mode => _mode;

  bool get isDark => _mode == ThemeMode.dark;

  Future<void> toggle() async {
    _mode = isDark ? ThemeMode.light : ThemeMode.dark;
    notifyListeners();
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_key, _mode.name);
  }

  Future<void> setMode(ThemeMode mode) async {
    if (_mode == mode) return;
    _mode = mode;
    notifyListeners();
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_key, mode.name);
  }

  /// Charge le thème persisté depuis les préférences
  static Future<ThemeProvider> load() async {
    final prefs = await SharedPreferences.getInstance();
    final stored = prefs.getString(_key);
    final mode = switch (stored) {
      'light' => ThemeMode.light,
      'dark'  => ThemeMode.dark,
      _       => ThemeMode.system,
    };
    return ThemeProvider(initial: mode);
  }
}