public void SwapToken(Address buyer, Address seller, string baseSymbol, string quoteSymbol, BigInteger tokenID, BigInteger price, byte[] signature)
{
Runtime.Expect(IsWitness(buyer), "invalid witness");
Runtime.Expect(seller != buyer, "invalid seller");
Runtime.Expect(Runtime.Nexus.TokenExists(baseSymbol), "invalid base token");
var baseToken = Runtime.Nexus.GetTokenInfo(baseSymbol);
Runtime.Expect(!baseToken.Flags.HasFlag(TokenFlags.Fungible), "token must be non-fungible");
var ownerships = new OwnershipSheet(baseSymbol);
var owner = ownerships.GetOwner(this.Storage, tokenID);
Runtime.Expect(owner == seller, "invalid owner");
var swap = new TokenSwap()
{
baseSymbol = baseSymbol,
quoteSymbol = quoteSymbol,
buyer = buyer,
seller = seller,
price = price,
value = tokenID,
};
var msg = Serialization.Serialize(swap);
Runtime.Expect(Ed25519.Verify(signature, msg, seller.PublicKey), "invalid signature");
Runtime.Expect(Runtime.Nexus.TokenExists(quoteSymbol), "invalid quote token");
var quoteToken = Runtime.Nexus.GetTokenInfo(quoteSymbol);
Runtime.Expect(quoteToken.Flags.HasFlag(TokenFlags.Fungible), "token must be fungible");
var balances = new BalanceSheet(quoteSymbol);
var balance = balances.Get(this.Storage, buyer);
Runtime.Expect(balance >= price, "invalid balance");
Runtime.Expect(Runtime.Nexus.TransferTokens(quoteSymbol, this.Storage, Runtime.Chain, buyer, owner, price), "payment failed");
Runtime.Expect(Runtime.Nexus.TransferToken(baseSymbol, this.Storage, Runtime.Chain, owner, buyer, tokenID), "transfer failed");
Runtime.Notify(EventKind.TokenSend, seller, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = baseSymbol, value = tokenID
});
Runtime.Notify(EventKind.TokenSend, buyer, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = quoteSymbol, value = price
});
Runtime.Notify(EventKind.TokenReceive, seller, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = quoteSymbol, value = price
});
Runtime.Notify(EventKind.TokenReceive, buyer, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = baseSymbol, value = tokenID
});
}
public void SwapTokens(Address buyer, Address seller, string baseSymbol, string quoteSymbol, BigInteger amount, BigInteger price, byte[] signature)
{
Runtime.Expect(IsWitness(buyer), "invalid witness");
Runtime.Expect(seller != buyer, "invalid seller");
var baseToken = Runtime.Nexus.FindTokenBySymbol(baseSymbol);
Runtime.Expect(baseToken != null, "invalid base token");
Runtime.Expect(baseToken.Flags.HasFlag(TokenFlags.Fungible), "token must be fungible");
var baseBalances = Runtime.Chain.GetTokenBalances(baseToken);
var baseBalance = baseBalances.Get(seller);
Runtime.Expect(baseBalance >= amount, "invalid amount");
var swap = new TokenSwap()
{
baseSymbol = baseSymbol,
quoteSymbol = quoteSymbol,
buyer = buyer,
seller = seller,
price = price,
value = amount,
};
var msg = Serialization.Serialize(swap);
Runtime.Expect(Ed25519.Verify(signature, msg, seller.PublicKey), "invalid signature");
var quoteToken = Runtime.Nexus.FindTokenBySymbol(quoteSymbol);
Runtime.Expect(quoteToken != null, "invalid base token");
Runtime.Expect(quoteToken.Flags.HasFlag(TokenFlags.Fungible), "token must be fungible");
var quoteBalances = Runtime.Chain.GetTokenBalances(quoteToken);
var quoteBalance = quoteBalances.Get(buyer);
Runtime.Expect(quoteBalance >= price, "invalid balance");
Runtime.Expect(quoteToken.Transfer(quoteBalances, buyer, seller, price), "payment failed");
Runtime.Expect(baseToken.Transfer(baseBalances, seller, buyer, amount), "transfer failed");
Runtime.Notify(EventKind.TokenSend, seller, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = baseSymbol, value = amount
});
Runtime.Notify(EventKind.TokenSend, buyer, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = quoteSymbol, value = price
});
Runtime.Notify(EventKind.TokenReceive, seller, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = quoteSymbol, value = price
});
Runtime.Notify(EventKind.TokenReceive, buyer, new TokenEventData()
{
chainAddress = Runtime.Chain.Address, symbol = baseSymbol, value = amount
});
}
