import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';
import '../models/user.dart';
import '../utils/constants.dart';
import 'api_service.dart';

class AuthService {
  static final AuthService _instance = AuthService._internal();
  factory AuthService() => _instance;
  AuthService._internal();

  final _storage = const FlutterSecureStorage();
  final _apiService = ApiService();

  User? _currentUser;
  User? get currentUser => _currentUser;
  bool get isAuthenticated => _currentUser != null;

  Future<bool> login(String email, String password) async {
    try {
      final response = await _apiService.login(email, password);
      final token = response['access_token'] as String;

      await _storage.write(key: AppConstants.storageKeyToken, value: token);
      _apiService.setAuthToken(token);

      _currentUser = await _apiService.getCurrentUser();

      final prefs = await SharedPreferences.getInstance();
      await prefs.setString(
        AppConstants.storageKeyUser,
        json.encode(_currentUser!.toJson()),
      );

      return true;
    } catch (e) {
      print('Login error: $e');
      return false;
    }
  }

  Future<bool> autoLogin() async {
    try {
      final token = await _storage.read(key: AppConstants.storageKeyToken);
      if (token == null) return false;

      _apiService.setAuthToken(token);
      _currentUser = await _apiService.getCurrentUser();
      return true;
    } catch (e) {
      print('Auto login error: $e');
      await logout();
      return false;
    }
  }

  Future<void> logout() async {
    _currentUser = null;
    _apiService.clearAuthToken();
    await _storage.delete(key: AppConstants.storageKeyToken);
    final prefs = await SharedPreferences.getInstance();
    await prefs.remove(AppConstants.storageKeyUser);
    await prefs.remove(AppConstants.storageKeyFcmToken);
  }

  Future<void> saveFcmToken(String fcmToken) async {
    try {
      await _apiService.registerFcmToken(fcmToken);
      final prefs = await SharedPreferences.getInstance();
      await prefs.setString(AppConstants.storageKeyFcmToken, fcmToken);
    } catch (e) {
      print('Error saving FCM token: $e');
    }
  }
}