// TODO: Make whole thing atomic with Unit of Work
public async Task <Result <Payment> > Handle(CreatePaymentCommand command, CancellationToken cancellationToken)
{
var cardDetails = new CardDetails(command.FirstName, command.Surname, command.CardNumber,
command.ExpiryMonth, command.ExpiryYear, command.CVV);
var currency = Enum.Parse <Currency>(command.Currency);
var payment = new Payment(Guid.NewGuid(), cardDetails, currency, command.Amount);
payment.SetSubmitting();
Result <Guid> acquiringBankResult = await _acquiringBankService.ProcessPayment(payment);
if (acquiringBankResult.IsSuccess)
{
// TODO: Use structured logging
_logger.LogInformation($"Acquiring bank processed payment {payment.Id} successfully");
payment.SetSuccess(acquiringBankResult.Value);
_domainEvent = new PaymentSuccessfulDomainEvent(payment);
}
else
{
_logger.LogWarning($"Acquiring bank would not process {payment.Id} {acquiringBankResult.Error}");
payment.SetFailure(acquiringBankResult.Error);
_domainEvent = new PaymentFailedDomainEvent(payment);
}
Result dbResult = await _paymentHistoryRepository.InsertPayment(payment);
if (dbResult.IsFailure)
{
_logger.LogError($"Failed to save the Payment {payment.Id} to the DB");
}
var eventStoreResult = await _eventStoreClient.Write(_domainEvent);
if (eventStoreResult.IsFailure)
{
_logger.LogError($"Failed to send the Domain Event for Payment {payment.Id} of type {_domainEvent.GetType()}");
}
if (dbResult.IsFailure)
{
return(Result.Failure <Payment>(CreatePaymentErrors.PaymentSaveFailed));
}
_metrics.Measure.Counter.Increment(MetricsRegistry.PaymentsCreatedCounter);
return(acquiringBankResult.IsSuccess
? Result.Ok(payment)
: Result.Failure <Payment>(CreatePaymentErrors.AcquiringBankRefusedPayment));
}
public async Task ProcessPayment(Payment paymentEntity)
{
var validationErrors = _validationService.Validate(paymentEntity);
if (validationErrors.Any())
{
paymentEntity.StatusCode = PaymentStatusCode.ValidationFailed;
// It would be better to return a list of error messages as well
return;
}
await _repository.Save(paymentEntity);
await _acquiringBankService.ProcessPayment(paymentEntity);
try
{
await _repository.Update(paymentEntity);
}
catch (Exception)
{
// See comments for Scenario 2.8 in readme.txt
}
}
public PaymentResponse ProcessPayment(ProcessPaymentRequest request, string merchantApiKey)
{
//Get merchant
var merchant = _merchantDao.GetMerchantBasedOnApiKey(merchantApiKey);
if (merchant == null)
{
Logger.Info("Request from an unknown merchant received");
throw new RequestValidationException("Unknown Merchant");
}
if (string.IsNullOrWhiteSpace(request.CardNumber))
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Missing Card Number");
throw new RequestValidationException("Missing Card Number");
}
if (!(request.CardNumber.Length == 19 || request.CardNumber.Length == 16))
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Invalid Card Number");
throw new RequestValidationException("Invalid Card Number");
}
if (string.IsNullOrWhiteSpace(request.CardCvv))
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Missing Card CVV Number");
throw new RequestValidationException("Missing Card CVV Number");
}
if (request.CardCvv.Length != 4)
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Invalid Card Card CVV Number");
throw new RequestValidationException("Invalid Card Card CVV Number");
}
if (request.PaymentAmount == 0)
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Invalid Payment Amount");
throw new RequestValidationException("Payment Amount should be greater than zero");
}
if (string.IsNullOrWhiteSpace(request.ExpiryDate))
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Missing Card Expiry Date");
throw new RequestValidationException("Missing Card Card Expiry Date");
}
DateTime expiryDate;
try
{
expiryDate = DateTime.ParseExact(request.ExpiryDate, _expiryDateFormat, CultureInfo.InvariantCulture);
}
catch (Exception e)
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Invalid ExpiryDate provided");
throw new RequestValidationException("Invalid ExpiryDate provided");
}
if (string.IsNullOrWhiteSpace(request.Currency))
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Missing Currency");
throw new RequestValidationException("Missing Currency");
}
var currency = GetCurrency(request);
if (currency == null)
{
Logger.Info($"Bad Request from MerchantId :{merchant.ID}, Unknown currency");
throw new RequestValidationException("Unknown Currency");
}
var card = GetOrCreateCard(request, expiryDate);
var paymentRequest = new PaymentRequest
{
MerchantId = merchant.ID,
CardId = card.ID,
CurrencyId = currency.ID,
Amount = request.PaymentAmount,
DateTimeAdded = DateTime.UtcNow
};
_paymentRequestDao.InsertPaymentRequest(paymentRequest);
paymentRequest =
_paymentRequestDao.GetPaymentRequestBasedOnMerchantIdCardIdCurrencyIdAndAmount(paymentRequest);
Logger.Info($"Payment request from Merchant: {merchant.ID} logged. PaymentRequestId : {paymentRequest.Id}");
var acquiringBankRequest = new AcquiringBankRequest
{
CardNumber = request.CardNumber,
CardCvv = request.CardCvv,
PaymentAmount = request.PaymentAmount,
ExpiryDate = request.ExpiryDate,
Currency = request.Currency,
MerchantId = merchant.ID
};
var response = _acquiringBankService.ProcessPayment(acquiringBankRequest);
var bankPaymentResponse = new BankPaymentResponse
{
PaymentRequestId = paymentRequest.Id,
Status = response.PaymentStatus,
BankPaymentIdentifier = response.PaymentIdentifier,
DateTimeAdded = DateTime.UtcNow
};
_bankPaymentResponseDao.InsertBankPaymentResponse(bankPaymentResponse);
return(new PaymentResponse
{
Status = response.PaymentStatus,
PaymentUniqueId = response.PaymentIdentifier
});
}