public async Task <bool> WaitOfferTakenAsync(OfferData offerData, CancellationToken cancellation = default(CancellationToken))
{
var decodedTxById = new Dictionary <uint256, JObject>();
var initiator = GetChain(offerData.Initiator.Asset.Chain);
var redeemHash = offerData.CreateRedeemScript().Hash;
int offset = 0;
int takeCount = 10;
while (true)
{
cancellation.ThrowIfCancellationRequested();
var transactions = await initiator.RPCClient.SendCommandAsync(RPCOperations.listtransactions, "*", takeCount, offset, true).ConfigureAwait(false);
offset += takeCount;
//If we reach end of the list, start over
if (transactions.Result == null || ((JArray)transactions.Result).Count() == 0)
{
offset = 0;
await Task.Delay(1000, cancellation).ConfigureAwait(false);
continue;
}
bool startOver = false;
//Check if the preimage is present
foreach (var tx in ((JArray)transactions.Result))
{
int confirmation = 0;
if (tx["confirmations"] != null)
{
confirmation = tx["confirmations"].Value <int>();
}
//Old transaction, skip
if (confirmation > 144)
{
startOver = true;
continue;
}
//Coinbase we can't have the preimage
var category = tx["category"]?.Value <string>();
if (category == "immature" || category == "generate")
{
continue;
}
var txId = new uint256(tx["txid"].Value <string>());
JObject txObj = null;
if (!decodedTxById.TryGetValue(txId, out txObj))
{
var getTransaction = await initiator.RPCClient.SendCommandAsync("gettransaction", txId.ToString(), true);
var decodeRawTransaction = await initiator.RPCClient.SendCommandAsync("decoderawtransaction", getTransaction.Result["hex"]);
txObj = (JObject)decodeRawTransaction.Result;
decodedTxById.Add(txId, txObj);
}
foreach (var input in txObj["vin"])
{
var scriptSig = input["scriptSig"]["asm"].Value <string>();
var sigParts = scriptSig.Split(' ').ToList();
// Add the hash in txin if segwit
if (input["txinwitness"] is JArray scriptWitness)
{
sigParts.AddRange(scriptWitness.Select(c => c.Value <string>()));
}
foreach (var sigPart in sigParts)
{
if (!HexEncoder.IsWellFormed(sigPart))
{
continue;
}
var preimage = new Preimage(Encoders.Hex.DecodeData(sigPart));
if (preimage.GetHash() == offerData.Hash)
{
_Repository.SavePreimage(preimage);
return(true);
}
}
}
}
//If we reach end of the list, start over
if (startOver)
{
offset = 0;
await Task.Delay(1000, cancellation).ConfigureAwait(false);
continue;
}
}
}
public async Task <uint256> TakeOffer(OfferData offer)
{
var taker = GetChain(offer.Taker.Asset.Chain);
var initiator = GetChain(offer.Initiator.Asset.Chain);
var preimage = _Repository.GetPreimage(offer.Hash);
if (preimage == null)
{
throw new InvalidOperationException("Unknown preimage");
}
var key = _Repository.GetPrivateKey(offer.Taker.PubKey);
if (key == null)
{
throw new InvalidOperationException("Unknown pubkey");
}
var offerOutpoint = _Repository.GetOffer(offer.CreateScriptPubkey());
if (offerOutpoint == null)
{
throw new InvalidOperationException("Unknown offer");
}
var destination = await initiator.RPCClient.GetNewAddressAsync().ConfigureAwait(false);
var tx = new Transaction();
tx.AddInput(new TxIn(offerOutpoint, offer.TakeOffer(new TransactionSignature(key.Sign(uint256.One), SigHash.All), preimage)));
tx.AddOutput(new TxOut(offer.Initiator.Asset.Amount, destination));
var fee = (await GetFeeAsync(initiator).ConfigureAwait(false)).GetFee(tx.GetVirtualSize());
tx.Outputs[0].Value -= fee;
var offerCoin = new Coin(offerOutpoint, new TxOut(offer.Initiator.Asset.Amount, offer.CreateScriptPubkey())).ToScriptCoin(offer.CreateRedeemScript());
var sig = tx.Inputs.AsIndexedInputs().First().Sign(key, offerCoin, SigHash.All);
tx.Inputs[0].ScriptSig = offer.TakeOffer(sig, preimage);
await initiator.RPCClient.SendRawTransactionAsync(tx).ConfigureAwait(false);
return(tx.GetHash());
}
