import 'dart:convert';
import 'package:p_tits_pas/services/api/api_config.dart';
import 'package:p_tits_pas/services/api/tokenService.dart';
import '../models/user.dart';
import 'package:http/http.dart' as http;


class AuthService {
  final String baseUrl = ApiConfig.baseUrl;

  //login
  Future<Map<String, dynamic>> login(String email, String password) async {
    try {
      final response = await http.post(
        Uri.parse('$baseUrl${ApiConfig.login}'),
        headers: ApiConfig.headers,
        body: jsonEncode({
          'email': email,
          'password': password
        }),
      );
      if (response.statusCode == 201) {
        final data = jsonDecode(response.body);

        await TokenService.saveToken(data['access_token']);
        await TokenService.saveRefreshToken(data['refresh_token']);
        final role = _extractRoleFromToken(data['access_token']);
        await TokenService.saveRole(role);

        return data;
      } else {
        throw Exception('Failed to login: ${response.body}');
      }
    } catch (e) {
      throw Exception('Failed to login: $e');
    }
  }

  String _extractRoleFromToken(String token) {
    try {
      final parts = token.split('.');
      if (parts.length != 3) return '';

      final payload = parts[1];
      final normalizedPayload = base64Url.normalize(payload);
      final decoded = utf8.decode(base64Url.decode(normalizedPayload));
      final Map<String, dynamic> payloadMap = jsonDecode(decoded);

      return payloadMap['role'] ?? '';
    } catch (e) {
      print('Error extracting role from token: $e');
      return '';
    }
  }

  Future<void> logout() async {
    await TokenService.clearAll();
  }

  Future<bool> isAuthenticated() async {
    final token = await TokenService.getToken();
    if (token == null) return false;

    return !_isTokenExpired(token);
  }

  bool _isTokenExpired(String token) {
    try {
      final parts = token.split('.');
      if (parts.length != 3) return true;

      final payload = parts[1];
      final normalizedPayload = base64Url.normalize(payload);
      final decoded = utf8.decode(base64Url.decode(normalizedPayload));
      final Map<String, dynamic> payloadMap = jsonDecode(decoded);

      final exp = payloadMap['exp'];
      if (exp == null) return true;

      final expirationDate = DateTime.fromMillisecondsSinceEpoch(exp * 1000);
      return DateTime.now().isAfter(expirationDate);
    } catch (e) {
      return true;
    }
  }

  //register
  Future<AppUser> register({
    required String email,
    required String password,
    required String firstName,
    required String lastName,
    required String role,
  }) async {
    final response = await http.post(
      Uri.parse('$baseUrl${ApiConfig.register}'),
      headers: {'Content-Type': 'application/json'},
      body: jsonEncode({
        'email': email,
        'password': password,
        'firstName': firstName,
        'lastName': lastName,
        'role': role,
      }),
    );

    if (response.statusCode == 201) {
      final data = jsonDecode(response.body);
      return AppUser.fromJson(data['user']);
    } else {
      throw Exception('Failed to register');
    }
  }

  Future<String> getUserId() async {
    final token = await TokenService.getToken();
    if (token == null) return '';

    try {
      final parts = token.split('.');
      if (parts.length != 3) return '';

      final payload = parts[1];
      final normalizedPayload = base64Url.normalize(payload);
      final decoded = utf8.decode(base64Url.decode(normalizedPayload));
      final Map<String, dynamic> payloadMap = jsonDecode(decoded);

      return payloadMap['sub'] ?? '';
    } catch (e) {
      print('Error extracting user id from token: $e');
      return '';
    }
  }

  Future<String?> getUserNameById() async {
    final userid = await getUserId();
    final token = await TokenService.getToken();

    if (token == null || userid.isEmpty) return null;
    try {
      final response = await http.get(
        Uri.parse('$baseUrl${ApiConfig.users}/$userid'),
        headers: {
          'Authorization': 'Bearer $token',
          'accept': '*/*',
        },
      );
      if (response.statusCode == 200) {
        final data = jsonDecode(response.body);
        final firstName = data['prenom'];
        // final lastName = data['nom'];
        return '$firstName';
      } else  {
        print('Erreur Api: ${response.statusCode} - ${response.body}');
        return null;
      }
    } catch (e) {
      print('Error fetching user name: $e');
      return null;
    }
  }
}