public async Task CompleteTxOutputs(Guid operationId, Transaction tx)
{
var inputs = tx.Inputs.Select(o => new Output(o.PrevOut)).ToList();
await SetInternalOutputsTxHash(operationId, tx.GetHash().ToString());
await _spentOutputRepository.InsertSpentOutputsAsync(operationId, inputs);
await RemoveUsedInternalOutputs(inputs);
}
public async Task CompleteTxOutputs(Guid operationId, NeoModules.NEP6.Transactions.Transaction tx)
{
var inputs = tx.Inputs.Select(o => new Output(o)).ToList();
await _spentOutputRepository.InsertSpentOutputsAsync(operationId, inputs);
}
/// <summary>
/// Builds a transaction that sends value from one address to another.
/// Change is spent to the source address, if necessary.
/// </summary>
/// <param name="request"></param>
/// <param name="feeFactor"></param>
/// <returns></returns>
/// <exception cref="BusinessException"></exception>
public async Task <BuildTransactionResponse> BuildSingleTransactionAsync(BuildSingleTransactionRequest request, decimal feeFactor)
{
if (string.IsNullOrWhiteSpace(request.FromAddress))
{
throw new BusinessException(ErrorReason.BadRequest, "FromAddress missing");
}
if (string.IsNullOrWhiteSpace(request.ToAddress))
{
throw new BusinessException(ErrorReason.BadRequest, "ToAddress missing");
}
if (!long.TryParse(request.Amount, out var amount) || amount <= 0)
{
throw new BusinessException(ErrorReason.BadRequest, $"Invalid amount {amount}");
}
var feePerKb = await _feeService.GetFeePerKb();
if (TransactionRules.IsDustAmount(amount, Transaction.PayToPubKeyHashPkScriptSize, new Amount(feePerKb)))
{
throw new BusinessException(ErrorReason.AmountTooSmall, "Amount is dust");
}
const int outputVersion = 0;
const int lockTime = 0;
const int expiry = 0;
// Number of outputs newly build tx will contain,
// not including the change address
const int numOutputs = 1;
// Lykke api doesn't have option to specify a change address.
var changeAddress = Address.Decode(request.FromAddress);
var toAddress = Address.Decode(request.ToAddress);
var allInputs = (await GetUtxosForAddress(request.FromAddress)).ToList();
long estFee = 0;
long totalSpent = 0;
var consumedInputs = new List <Transaction.Input>();
bool HasEnoughInputs(out long fee)
{
var calculateWithChange = false;
while (true)
{
var changeCount = calculateWithChange ? 1 : 0;
fee = _feeService.CalculateFee(feePerKb, consumedInputs.Count, numOutputs + changeCount, feeFactor);
var estAmount = amount + (request.IncludeFee ? 0 : fee);
if (totalSpent < estAmount)
{
return(false);
}
if (totalSpent == estAmount)
{
return(true);
}
if (totalSpent > estAmount && calculateWithChange)
{
return(true);
}
// Loop one more time but make sure change is accounted for this time.
if (totalSpent > estAmount)
{
calculateWithChange = true;
}
}
}
// Accumulate inputs until we have enough to cover the cost
// of the amount + fee
foreach (var input in allInputs)
{
consumedInputs.Add(input);
totalSpent += input.InputAmount;
if (HasEnoughInputs(out estFee))
{
break;
}
}
// If all inputs do not have enough value to fund the transaction.
if (totalSpent < amount + (request.IncludeFee ? 0 : estFee))
{
throw new BusinessException(ErrorReason.NotEnoughBalance, "Address balance too low");
}
// The fee either comes from the change or the sent amount
var send = amount - (request.IncludeFee ? estFee : 0);
var change = (totalSpent - amount) - (request.IncludeFee ? 0 : estFee);
// If all inputs do not have enough value to fund the transaction, throw error.
if (request.IncludeFee && estFee > amount)
{
throw new BusinessException(ErrorReason.AmountTooSmall, "Amount not enough to include fee");
}
// If all inputs do not have enough value to fund the transaction, throw error.
if (totalSpent < amount + (request.IncludeFee ? 0 : estFee))
{
throw new BusinessException(ErrorReason.NotEnoughBalance, "Address balance too low");
}
// Build outputs to address + change address.
// If any of the outputs is zero value, exclude it. For example, if there is no change.
var outputs = new[] {
new Transaction.Output(send, outputVersion, toAddress.BuildScript().Script),
new Transaction.Output(change, outputVersion, changeAddress.BuildScript().Script)
}.Where(o => o.Amount != 0).ToArray();
var newTx = new Transaction(
Transaction.SupportedVersion,
consumedInputs.ToArray(),
outputs,
lockTime,
expiry
);
await _spentOutputRepository.InsertSpentOutputsAsync(request.OperationId,
consumedInputs.Select(p => new Output(p.PreviousOutpoint.Hash.ToString(), p.PreviousOutpoint.Index)));
return(new BuildTransactionResponse
{
TransactionContext = HexUtil.FromByteArray(newTx.Serialize())
});
}