authenticate method

Implementation

@override
Future<Set<Token>> authenticate({required String username, required String password, required Set<Webservice> webservices}) async {
  log('Authenticating user $username for ${webservices.map((webService) => webService.name).join(', ')}');

  const url = '$kMoodleServerAdress/login/token.php';

  final tokens = <Token>{};

  for (final webservice in webservices) {
    final response = await _networkService.post(
      url,
      {
        'username': username,
        'password': password,
        'service': webservice.name,
        'moodlewsrestformat': 'json',
      },
      headers: {'Content-Type': 'application/x-www-form-urlencoded'},
    );

    if (response.isNotOk) {
      final e = AuthException(response, webservice);

      log('Authentication failed', e);

      throw e;
    }

    final json = response.body as JSON;

    final token = json['token'] as String?;

    if (token == null) {
      final e = _parseError(json, webservice);

      log('Authentication failed', e);

      throw e;
    }

    tokens.add(Token(token: token, webservice: webservice));

    log('Authenticated user $username for ${webservice.name}');
  }

  return tokens;
}