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

class AuthService {
  final ApiService _apiService;
  final FlutterSecureStorage _storage = const FlutterSecureStorage();

  static const String _userKey = 'captain_user';

  AuthService(this._apiService);

  Future<User?> login(String username, String password) async {
    try {
      final response = await _apiService.login(username, password);
      final user = User(
        username: username,
        token: response['token'],
        expiresAt: DateTime.parse(response['expires_at']),
      );

      await _saveUser(user);
      _apiService.setToken(user.token);

      return user;
    } catch (e) {
      return null;
    }
  }

  Future<User?> getStoredUser() async {
    try {
      final data = await _storage.read(key: _userKey);
      if (data == null) return null;

      final user = User.fromJson(jsonDecode(data));
      if (user.isExpired) {
        await logout();
        return null;
      }

      _apiService.setToken(user.token);
      return user;
    } catch (e) {
      return null;
    }
  }

  Future<void> _saveUser(User user) async {
    await _storage.write(
      key: _userKey,
      value: jsonEncode(user.toJson()),
    );
  }

  Future<void> logout() async {
    await _storage.delete(key: _userKey);
    _apiService.setToken(null);
  }
}