Files
tycho-protocol-sdk/evm/src/uniswap-v2/UniswapV2SwapAdapter.sol
2023-12-04 13:52:23 +01:00

328 lines
10 KiB
Solidity

// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity ^0.8.13;
import {IERC20, ISwapAdapter} from "src/interfaces/ISwapAdapter.sol";
uint256 constant RESERVE_LIMIT_FACTOR = 10; // TODO why is the factor so high?
contract UniswapV2SwapAdapter is ISwapAdapter {
IUniswapV2Factory immutable factory;
constructor(address factory_) {
factory = IUniswapV2Factory(factory_);
}
function price(
bytes32 pairId,
IERC20 sellToken,
IERC20 buyToken,
uint256[] memory sellAmounts
) external view override returns (Fraction[] memory prices) {
prices = new Fraction[](sellAmounts.length);
IUniswapV2Pair pair = IUniswapV2Pair(address(bytes20(pairId)));
uint112 r0;
uint112 r1;
if (sellToken < buyToken) {
(r0, r1,) = pair.getReserves();
} else {
(r1, r0,) = pair.getReserves();
}
for (uint256 i = 0; i < sellAmounts.length; i++) {
prices[i] = getPriceAt(sellAmounts[i], r0, r1);
}
}
function getPriceAt(uint256 amountIn, uint256 reserveIn, uint256 reserveOut)
internal
pure
returns (Fraction memory)
{
if (reserveIn == 0 || reserveOut == 0) {
revert Unavailable("At least one reserve is zero!");
}
uint256 amountInWithFee = amountIn * 997;
uint256 numerator = amountInWithFee * reserveOut;
uint256 denominator = (reserveIn * 1000) + amountInWithFee;
uint256 amountOut = numerator / denominator;
uint256 newReserveOut = reserveOut - amountOut;
uint256 newReserveIn = reserveIn + amountIn;
return Fraction(newReserveOut * 1000, newReserveIn * 997);
}
function swap(
bytes32 pairId,
IERC20 sellToken,
IERC20 buyToken,
OrderSide side,
uint256 specifiedAmount
) external override returns (Trade memory trade) {
if (specifiedAmount == 0) {
return trade; // TODO: This returns Fraction(0, 0) instead of the
// expected zero Fraction(0, 1)
}
IUniswapV2Pair pair = IUniswapV2Pair(address(bytes20(pairId)));
uint112 r0;
uint112 r1;
bool zero2one = sellToken < buyToken;
if (zero2one) {
(r0, r1,) = pair.getReserves();
} else {
(r1, r0,) = pair.getReserves();
}
uint256 gasBefore = gasleft();
if (side == OrderSide.Sell) {
trade.receivedAmount =
sell(pair, sellToken, zero2one, r0, r1, specifiedAmount);
} else {
trade.receivedAmount =
buy(pair, sellToken, zero2one, r0, r1, specifiedAmount);
}
trade.gasUsed = gasBefore - gasleft();
trade.price = getPriceAt(specifiedAmount, r0, r1);
}
function sell(
IUniswapV2Pair pair,
IERC20 sellToken,
bool zero2one,
uint112 reserveIn,
uint112 reserveOut,
uint256 amount
) internal returns (uint256 receivedAmount) {
address swapper = msg.sender;
// TODO: use safeTransferFrom
sellToken.transferFrom(swapper, address(pair), amount);
uint256 amountOut = getAmountOut(amount, reserveIn, reserveOut);
if (zero2one) {
pair.swap(0, amountOut, swapper, "");
} else {
pair.swap(amountOut, 0, swapper, "");
}
return amountOut;
}
// Given an input amount of an asset and pair reserves, returns the maximum
// output amount of the other asset
function getAmountOut(
uint256 amountIn,
uint256 reserveIn,
uint256 reserveOut
) internal pure returns (uint256 amountOut) {
if (amountIn == 0) {
return 0;
}
if (reserveIn == 0 || reserveOut == 0) {
revert Unavailable("At least one reserve is zero!");
}
uint256 amountInWithFee = amountIn * 997;
uint256 numerator = amountInWithFee * reserveOut;
uint256 denominator = reserveIn * 1000 + amountInWithFee;
amountOut = numerator / denominator;
}
function buy(
IUniswapV2Pair pair,
IERC20 sellToken,
bool zero2one,
uint112 reserveIn,
uint112 reserveOut,
uint256 amountOut
) internal returns (uint256 receivedAmount) {
address swapper = msg.sender;
uint256 amount = getAmountIn(amountOut, reserveIn, reserveOut);
if (amount == 0) {
return 0;
}
// TODO: use safeTransferFrom
sellToken.transferFrom(swapper, address(pair), amount);
if (zero2one) {
pair.swap(0, amountOut, swapper, "");
} else {
pair.swap(amountOut, 0, swapper, "");
}
return amount;
}
// given an output amount of an asset and pair reserves, returns a required
// input amount of the other asset
function getAmountIn(
uint256 amountOut,
uint256 reserveIn,
uint256 reserveOut
) internal pure returns (uint256 amountIn) {
if (amountIn == 0) {
return 0;
}
if (reserveIn == 0) {
revert Unavailable("reserveIn is zero");
}
if (reserveOut == 0) {
revert Unavailable("reserveOut is zero");
}
uint256 numerator = reserveIn * amountOut * 1000;
uint256 denominator = (reserveOut - amountOut) * 997;
amountIn = (numerator / denominator) + 1;
}
function getLimits(bytes32 pairId, IERC20 sellToken, IERC20 buyToken)
external
view
override
returns (uint256[] memory limits)
{
IUniswapV2Pair pair = IUniswapV2Pair(address(bytes20(pairId)));
limits = new uint256[](2);
if (sellToken < buyToken) {
(limits[0], limits[1],) = pair.getReserves();
} else {
(limits[1], limits[0],) = pair.getReserves();
}
}
function getCapabilities(bytes32, IERC20, IERC20)
external
pure
override
returns (Capability[] memory capabilities)
{
capabilities = new Capability[](3);
capabilities[0] = Capability.SellOrder;
capabilities[1] = Capability.BuyOrder;
capabilities[2] = Capability.PriceFunction;
}
function getTokens(bytes32 pairId)
external
view
override
returns (IERC20[] memory tokens)
{
tokens = new IERC20[](2);
IUniswapV2Pair pair = IUniswapV2Pair(address(bytes20(pairId)));
tokens[0] = IERC20(pair.token0());
tokens[1] = IERC20(pair.token1());
}
function getPoolIds(uint256 offset, uint256 limit)
external
view
override
returns (bytes32[] memory ids)
{
uint256 endIdx = offset + limit;
if (endIdx > factory.allPairsLength()) {
endIdx = factory.allPairsLength();
}
ids = new bytes32[](endIdx - offset);
for (uint256 i = 0; i < ids.length; i++) {
ids[i] = bytes20(factory.allPairs(offset + i));
}
}
}
interface IUniswapV2Pair {
event Approval(
address indexed owner, address indexed spender, uint256 value
);
event Transfer(address indexed from, address indexed to, uint256 value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint256);
function balanceOf(address owner) external view returns (uint256);
function allowance(address owner, address spender)
external
view
returns (uint256);
function approve(address spender, uint256 value) external returns (bool);
function transfer(address to, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value)
external
returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint256);
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
event Mint(address indexed sender, uint256 amount0, uint256 amount1);
event Burn(
address indexed sender,
uint256 amount0,
uint256 amount1,
address indexed to
);
event Swap(
address indexed sender,
uint256 amount0In,
uint256 amount1In,
uint256 amount0Out,
uint256 amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint256);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves()
external
view
returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint256);
function price1CumulativeLast() external view returns (uint256);
function kLast() external view returns (uint256);
function mint(address to) external returns (uint256 liquidity);
function burn(address to)
external
returns (uint256 amount0, uint256 amount1);
function swap(
uint256 amount0Out,
uint256 amount1Out,
address to,
bytes calldata data
) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IUniswapV2Factory {
event PairCreated(
address indexed token0, address indexed token1, address pair, uint256
);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(address tokenA, address tokenB)
external
view
returns (address pair);
function allPairs(uint256) external view returns (address pair);
function allPairsLength() external view returns (uint256);
function createPair(address tokenA, address tokenB)
external
returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}