private static bool CancelOffer(object[] args, byte[] sender)
{
if (args.Length != 1)
{
return(false);
}
byte[] offerIdToCancel = (byte[])args[0];
string errMsg = "offerId not found";
if (offerIdToCancel.Length != 32)
{
goto CancelOfferError;
}
// We use a prefix and verify the length to ensure the onwer can't potentially use a bogus offerId of
// an asset setting and make a fake offer to increase their balance of an asset
byte[] offerKey = PREFIX_OFFERS.Concat(offerIdToCancel);
byte[] offerData = Storage.Get(Storage.CurrentContext, offerKey);
if (offerData.Length == 0)
{
goto CancelOfferError;
}
Offer offer = (Offer)offerData.Deserialize();
if (Runtime.CheckWitness(offer.Creator) == false && VerifyOwner() == false && VerifyManager() == false)
{
errMsg = "No permission";
goto CancelOfferError;
}
IncreaseBalanceOf(offer.AssetIdToSell, offer.Creator, offer.QuantityToSell);
Storage.Delete(Storage.CurrentContext, offerKey);
Runtime.Notify("offerCanceled", offer.Creator, offerIdToCancel);
return(true);
CancelOfferError:
Runtime.Notify("cancelOfferError", errMsg, sender, offerIdToCancel);
return(false);
}
private static bool AddOffer(object[] args, byte[] sender)
{
object[] notifyArgs;
string firstNotifyArg = "addOfferInitError";
Offer offer = new Offer();
offer.Creator = sender;
offer.AssetIdToBuy = (byte[])args[0];
BigInteger quantityToBuy = (BigInteger)args[1];
offer.QuantityToBuy = quantityToBuy;
offer.AssetIdToSell = (byte[])args[2];
BigInteger quantityToSell = (BigInteger)args[3];
offer.QuantityToSell = quantityToSell;
offer.Nonce = (BigInteger)args[4];
if (offer.AssetIdToBuy.Length != 32 && offer.AssetIdToBuy.Length != 20 ||
offer.AssetIdToSell.Length != 32 && offer.AssetIdToSell.Length != 20)
{
notifyArgs = new object[] { null, "Invalid Asset Length", sender, offer.AssetIdToBuy, offer.AssetIdToSell };
goto AddOfferErrorNotify;
}
if (quantityToBuy <= 0 || quantityToSell <= 0)
{
notifyArgs = new object[] { null, "No negative quantities allowed", sender, quantityToBuy, quantityToSell };
goto AddOfferErrorNotify;
}
byte[] offerData = offer.Serialize();
byte[] offerId = Hash256(offerData);
byte[] offerKey = PREFIX_OFFERS.Concat(offerId);
byte[] existingOfferData = Storage.Get(Storage.CurrentContext, offerKey);
if (existingOfferData.Length > 0)
{
notifyArgs = new object[] { null, "Offer already exists", sender, offerId };
goto AddOfferErrorNotify;
}
firstNotifyArg = "addOfferError";
var existingWhitelistedUserIdentity = Storage.Get(Storage.CurrentContext, PREFIX_WHITELIST.Concat(sender));
if (existingWhitelistedUserIdentity.Length == 0)
{
notifyArgs = new object[] { null, "Not whitelisted", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell };
goto AddOfferErrorNotify;
}
//validate this is a market we currently support and the order size is enough
Market offerMarket = GetMarket(offer.AssetIdToBuy, offer.AssetIdToSell);
if (offerMarket.QuoteAssetId.Length == 0)
{
notifyArgs = new object[] { null, "Invalid market", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell };
goto AddOfferErrorNotify;
}
BigInteger minimumTickSize = offerMarket.MinimumTickSize;
if (offer.AssetIdToBuy == offerMarket.QuoteAssetId)
{
if (quantityToBuy < offerMarket.MinimumSize)
{
notifyArgs = new object[] { null, "Insufficient order size", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell, quantityToBuy, minimumTickSize };
goto AddOfferErrorNotify;
}
BigInteger unitPrice = (quantityToSell * ONE) / quantityToBuy;
if ((unitPrice / minimumTickSize) * minimumTickSize != unitPrice)
{
notifyArgs = new object[] { null, "Invalid tick size", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell, unitPrice, minimumTickSize };
goto AddOfferErrorNotify;
}
}
else
{
if (quantityToSell < offerMarket.MinimumSize)
{
notifyArgs = new object[] { null, "Insufficient order size", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell, quantityToSell, minimumTickSize };
goto AddOfferErrorNotify;
}
BigInteger unitPrice = (quantityToBuy * ONE) / quantityToSell;
if ((unitPrice / minimumTickSize) * minimumTickSize != unitPrice)
{
notifyArgs = new object[] { null, "Invalid tick size", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell, unitPrice, minimumTickSize };
goto AddOfferErrorNotify;
}
}
bool reduced = ReduceBalanceOf(offer.AssetIdToSell, sender, quantityToSell);
if (reduced == false)
{
notifyArgs = new object[] { null, "Unable to reserve asset", sender, offerId, offer.AssetIdToBuy, offer.AssetIdToSell, quantityToSell };
goto AddOfferErrorNotify;
}
Storage.Put(Storage.CurrentContext, offerKey, offerData);
// Runtime.Notify("PostOffer", sender, offerId, offerData);
Runtime.Notify("offerCreated", offerId, offer.Creator, offer.AssetIdToBuy, quantityToBuy, offer.AssetIdToSell, quantityToSell);
return(true);
AddOfferErrorNotify:
notifyArgs[0] = firstNotifyArg;
Runtime.Notify(notifyArgs);
return(false);
}
private static bool AcceptOffer(object[] args)
{
byte[] offerIdToAccept = (byte[])args[0];
byte[] takerAddress = (byte[])args[1];
byte[] assetIdToGive = (byte[])args[2];
BigInteger quantityToGive = (BigInteger)args[3];
byte[] assetIdToReceive = (byte[])args[4];
BigInteger quantityToReceive = (BigInteger)args[5];
object[] notifyArgs;
Market offerMarket = GetMarket(assetIdToGive, assetIdToReceive);
if (offerMarket.QuoteAssetId.Length == 0)
{
notifyArgs = new object[] { null, "acceptOfferInvalidMarket", takerAddress, assetIdToGive, assetIdToReceive };
goto AcceptOfferErrorNotify;
}
BigInteger quoteQuantity = assetIdToGive == offerMarket.QuoteAssetId ? quantityToGive : quantityToReceive;
BigInteger baseQuantity = assetIdToGive == offerMarket.QuoteAssetId ? quantityToReceive : quantityToGive;
if (Runtime.CheckWitness(takerAddress) == false)
{
notifyArgs = new object[] { null, "takerAddress not a witness", takerAddress, offerIdToAccept, quoteQuantity };
goto AcceptOfferErrorNotify;
}
byte[] offerKey = PREFIX_OFFERS.Concat(offerIdToAccept);
byte[] offerData = Storage.Get(Storage.CurrentContext, offerKey);
if (offerData.Length == 0)
{
if ((bool)args[6] == true) // createIfMissing
{
BigInteger nonce = (BigInteger)args[7];
Runtime.Notify("acceptOfferCreatesOffer", "OfferId not found; Creating a new offer", takerAddress, offerIdToAccept, quoteQuantity);
return(AddOffer(new object[]
{
assetIdToReceive, quantityToReceive,
assetIdToGive, quantityToGive,
nonce
}, takerAddress));
}
notifyArgs = new object[] { null, "OfferId not found", takerAddress, offerIdToAccept, quoteQuantity, args[6] };
goto AcceptOfferErrorNotify;
}
Offer offer = (Offer)offerData.Deserialize();
if (offer.AssetIdToBuy != assetIdToGive)
{
notifyArgs = new object[] { null, "Invalid asset to give", takerAddress, offerIdToAccept, quoteQuantity, offer.AssetIdToBuy, assetIdToGive };
goto AcceptOfferErrorNotify;
}
if (offer.AssetIdToSell != assetIdToReceive)
{
notifyArgs = new object[] { null, "Invalid asset to receive", takerAddress, offerIdToAccept, quoteQuantity, offer.AssetIdToSell, assetIdToReceive };
goto AcceptOfferErrorNotify;
}
if (quantityToGive <= 0)
{
notifyArgs = new object[] { null, "Invalid quantity to give, <= 0", takerAddress, offerIdToAccept, quoteQuantity, quantityToGive };
goto AcceptOfferErrorNotify;
}
if (quantityToReceive <= 0)
{
notifyArgs = new object[] { null, "Invalid quantity to receive, <= 0", takerAddress, offerIdToAccept, quoteQuantity, quantityToReceive };
goto AcceptOfferErrorNotify;
}
if (quantityToGive > offer.QuantityToBuy)
{
// Runtime.Notify(acceptOfferErrorStr, "Invalid quantity to give, more than offered", takerAddress, offerIdToAccept, quoteQuantity, offer.QuantityToBuy);
quantityToGive = offer.QuantityToBuy;
quantityToReceive = (offer.QuantityToBuy / quantityToGive) * quantityToReceive;
}
else if (quantityToGive < offer.QuantityToBuy)
{
if (offer.AssetIdToBuy == offerMarket.QuoteAssetId)
{
if (offer.QuantityToBuy - quantityToGive < offerMarket.MinimumSize)
{
notifyArgs = new object[] { null, "Would leave <min size", takerAddress, offerIdToAccept, quoteQuantity, offer.AssetIdToBuy, offer.QuantityToBuy - quantityToGive, offerMarket.MinimumSize };
goto AcceptOfferErrorNotify;
}
}
else
{
if (offer.QuantityToSell - quantityToReceive < offerMarket.MinimumSize)
{
notifyArgs = new object[] { null, "Would leave <min size", takerAddress, offerIdToAccept, quoteQuantity, offer.AssetIdToSell, offer.QuantityToSell - quantityToReceive, offerMarket.MinimumSize };
goto AcceptOfferErrorNotify;
}
}
}
BigInteger calculatedQuantityToReceive = (quantityToGive * offer.QuantityToSell) / offer.QuantityToBuy;
if (quantityToReceive != calculatedQuantityToReceive)
{
notifyArgs = new object[] { null, "Receive Quantity != calculated", takerAddress, offerIdToAccept, quoteQuantity, offerIdToAccept, quantityToReceive, calculatedQuantityToReceive };
goto AcceptOfferErrorNotify;
}
BigInteger feePercentage = assetIdToGive == offerMarket.QuoteAssetId ? offerMarket.SellFeePercent : offerMarket.BuyFeePercent;
BigInteger baseAssetToAphConversionRate = GetAssetToAphConversionRate(offerMarket.BaseAssetId);
BigInteger fee = baseQuantity * baseAssetToAphConversionRate * feePercentage / ONE / ONE;
// Take away what the taker sold
if (NoPullReduceBalanceOf(assetIdToGive, takerAddress, quantityToGive) == false)
{
notifyArgs = new object[] { null, "Insufficient balance of asset", takerAddress, offerIdToAccept, quoteQuantity, assetIdToGive };
goto AcceptOfferErrorNotify;
}
// ** FEES **
// if (fee > 0) // Removed - SetMarket gaurantees fees cannot be negative, and we need to reduce worst case GAS cost.
//charge the fees to the taker
if (NoPullReduceBalanceOf(APH, takerAddress, fee) == false)
{
//refund the asset the taker sold, wasn't able to charge fees
IncreaseBalanceOf(assetIdToGive, takerAddress, quantityToGive);
notifyArgs = new object[] { null, "Insufficient APH for trade fee", takerAddress, offerIdToAccept, quoteQuantity, assetIdToGive };
goto AcceptOfferErrorNotify;
}
// Give them to the distribution pool
FeeCollected(fee);
// ** END FEES **
// Give the maker what they bought
IncreaseBalanceOf(assetIdToGive, offer.Creator, quantityToGive);
offer.QuantityToSell -= quantityToReceive;
offer.QuantityToBuy -= quantityToGive;
// Update to close out the order
if (offer.QuantityToBuy == 0)
{
Storage.Delete(Storage.CurrentContext, offerKey);
}
else
{
byte[] updatedData = offer.Serialize();
Storage.Put(Storage.CurrentContext, offerKey, updatedData);
}
// Give the taker what they bought (do last in case the taker somehow maliciously causes the invocation to run out of gas, they won't get what they bought)
IncreaseBalanceOf(assetIdToReceive, takerAddress, quantityToReceive);
Runtime.Notify("offerAccepted", takerAddress, offerIdToAccept, offer.QuantityToBuy, offer.QuantityToSell);
return(true);
AcceptOfferErrorNotify:
notifyArgs[0] = "acceptOfferError";
Runtime.Notify(notifyArgs);
return(false);
}
