public async Task <string> CreateTransaction(int userId, CreateTransactionModel transactionModel)
{
var semaphore = dictionary.GetOrAdd(userId, new SemaphoreSlim(1, 1));
await semaphore.WaitAsync();
try
{
var balance = await _balanceRepository.GetBalance(userId);
if (balance < transactionModel.Amount)
{
return(ErrorDictionary.BalanceSmallerThenAmount);
}
var date = DateTime.UtcNow;
var transactionId = await AddTransaction(userId, (int)transactionModel.CorrespondentId, date);
var negativeBalance = new Balance();
var positiveBalance = new Balance();
negativeBalance.Amount = -(int)transactionModel.Amount;
positiveBalance.Amount = (int)transactionModel.Amount;
negativeBalance.CreationDate = positiveBalance.CreationDate = date;
negativeBalance.TransferTransactionId = positiveBalance.TransferTransactionId = transactionId;
negativeBalance.UserId = userId;
positiveBalance.UserId = (int)transactionModel.CorrespondentId;
var result = await _balanceRepository.AddBalanceEntries(new List <Balance>() { negativeBalance, positiveBalance });
if (result.All(c => c.Id > 0))
{
return(ErrorDictionary.Ok);
}
else
{
await _balanceRepository.RemoveBalanceEntry(result.FirstOrDefault(c => c.Id > 0));
await _transferTransactionRepository.RemoveTransaction(transactionId);
return(ErrorDictionary.Error);
}
}
finally
{
semaphore.Release();
}
}
