/// <summary>
/// 移除流动性
/// </summary>
/// <param name="sender"></param>
/// <param name="tokenA"></param>
/// <param name="tokenB"></param>
/// <param name="liquidity">移除的liquidity Token量</param>
/// <param name="amountAMin">tokenA 期望最小提取量,Bounds the extent to which the B/A price can go up before the transaction reverts. Must be <= amountADesired.</param>
/// <param name="amountBMin">tokenB 期望最小提取量</param>
/// <param name="deadLine"></param>
/// <returns></returns>
public static BigInteger[] RemoveLiquidity(UInt160 sender, UInt160 tokenA, UInt160 tokenB, BigInteger liquidity, BigInteger amountAMin, BigInteger amountBMin, BigInteger deadLine)
{
//验证权限
Assert(Runtime.CheckWitness(sender), "Forbidden");
//看看有没有超过最后期限
Assert((BigInteger)Runtime.Time <= deadLine, "Exceeded the deadline");
var pairContract = GetExchangePairWithAssert(tokenA, tokenB);
SafeTransfer(pairContract, sender, pairContract, liquidity);
var amounts = pairContract.DynamicBurn(sender);
//var amounts = (byte[])Contract.Call(pairContract, "burn", CallFlags.All, sender);
var tokenAIsToken0 = tokenA.ToUInteger() < tokenB.ToUInteger();
var amountA = tokenAIsToken0 ? amounts[0] : amounts[1];
var amountB = tokenAIsToken0 ? amounts[1] : amounts[0];
Assert(amountA >= amountAMin, "Insufficient A Amount");
Assert(amountB >= amountBMin, "Insufficient B Amount");
return(new BigInteger[] { amountA, amountB });
}
/// <summary>
/// 查询TokenA,TokenB交易对合约的里的持有量并按A、B顺序返回
/// </summary>
/// <param name="tokenA"></param>
/// <param name="tokenB"></param>
/// <returns></returns>
public static BigInteger[] GetReserves(UInt160 tokenA, UInt160 tokenB)
{
var reserveData = (ReservesData)Contract.Call(GetExchangePairWithAssert(tokenA, tokenB), "getReserves", CallFlags.ReadOnly, new object[] { });
return(tokenA.ToUInteger() < tokenB.ToUInteger() ? new BigInteger[] { reserveData.Reserve0, reserveData.Reserve1 } : new BigInteger[] { reserveData.Reserve1, reserveData.Reserve0 });
}
/// <summary>
/// 获取pair
/// </summary>
/// <param name="tokenA"></param>
/// <param name="tokenB"></param>
/// <returns></returns>
private static byte[] GetPairKey(UInt160 tokenA, UInt160 tokenB)
{
return(tokenA.ToUInteger() < tokenB.ToUInteger()
? ExchangeMapKey.Concat(tokenA).Concat(tokenB)
: ExchangeMapKey.Concat(tokenB).Concat(tokenA));
}
