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

class ThemeProvider extends ChangeNotifier {
  static const String _themeKey = 'theme_mode';
  ThemeMode _themeMode = ThemeMode.system;

  ThemeMode get theme => _themeMode;

  ThemeProvider() {
    _loadTheme();
  }

  Future<void> _loadTheme() async {
    final prefs = await SharedPreferences.getInstance();
    final themeName = prefs.getString(_themeKey) ?? 'system';
    _themeMode = _themeFromString(themeName);
    notifyListeners();
  }

  Future<void> setTheme(ThemeMode mode) async {
    _themeMode = mode;
    notifyListeners();
    
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_themeKey, _themeToString(mode));
  }

  String _themeToString(ThemeMode mode) {
    switch (mode) {
      case ThemeMode.light:
        return 'light';
      case ThemeMode.dark:
        return 'dark';
      case ThemeMode.system:
        return 'system';
    }
  }

  ThemeMode _themeFromString(String theme) {
    switch (theme) {
      case 'light':
        return ThemeMode.light;
      case 'dark':
        return ThemeMode.dark;
      case 'system':
      default:
        return ThemeMode.system;
    }
  }
}