getPaymentId method

Future<String?> getPaymentId({ required String id, required String secret, required String subject, required String amount, required String currency, String? email, })

Implementation

Future<String?> getPaymentId({
  required String id,
  required String secret,
  required String subject,
  required String amount,
  required String currency,
  String? email,
}) async {
  validateFields(id, secret, subject, amount, currency, email);

  String method = "POST";
  var url = 'https://khipu.com/api/2.0/payments';

  var toSign = new StringBuffer(
      method.toUpperCase() + "&" + encryptData.percentEncode(url));

  Map parameters = new Map<String, dynamic>();
  parameters["subject"] = removeDiacritics(subject);
  parameters["amount"] = amount;
  parameters["currency"] = currency;
  if (email != null && email.isNotEmpty) parameters["payer_email"] = email;

  var sortedKeys = parameters.keys.toList()..sort();
  for (var key in sortedKeys) {
    toSign.write('&' +
        encryptData.percentEncode(key) +
        '=' +
        encryptData.percentEncode(parameters[key]));
  }

  String sign = encryptData.hmacSHA256(secret, toSign.toString());
  String authorization = '$id' + ':' + sign;

  var postData = new StringBuffer();
  for (var key in parameters.keys) {
    if (postData.length > 0) {
      postData.write('&' +
          encryptData.percentEncode(key) +
          '=' +
          encryptData.percentEncode(parameters[key]));
    } else {
      postData.write(encryptData.percentEncode(key) +
          '=' +
          encryptData.percentEncode(parameters[key]));
    }
  }

  var response = await http.post(
    Uri.parse('$url?${postData.toString()}'),
    headers: {
      'Authorization': authorization,
      'Content-Type': 'application/x-www-form-urlencoded',
    },
  );

  if (response.statusCode == 200 || response.statusCode == 201) {
    final Map responseMap = json.decode(response.body);
    print("paymentId: " + responseMap["payment_id"]);
    return responseMap["payment_id"];
  } else {
    final Map responseMap = json.decode(response.body);
    print(responseMap);
    return responseMap["message"];
  }
}