2022-05-18 19:53:50 -04:00

96 lines
2.8 KiB
Solidity

pragma solidity ^0.6;
pragma experimental ABIEncoderV2;
import "./interfaces/IGMX.sol";
import "./ApproximateBuys.sol";
import "./SamplerUtils.sol";
contract GMXSampler is
SamplerUtils,
ApproximateBuys
{
struct GMXInfo {
address reader;
address vault;
address[] path;
}
function sampleSellsFromGMX(
address reader,
address vault,
address[] memory path,
uint256[] memory takerTokenAmounts
)
public
view
returns (uint256[] memory makerTokenAmounts)
{
uint256 numSamples = takerTokenAmounts.length;
makerTokenAmounts = new uint256[](numSamples);
for (uint256 i = 0; i < numSamples; i++) {
try
IGMX(reader).getAmountOut(IVault(vault), path[0], path[1], takerTokenAmounts[i])
returns (uint256 amountAfterFees, uint256 feeAmount)
{
makerTokenAmounts[i] = amountAfterFees;
// Break early if there are 0 amounts
if (makerTokenAmounts[i] == 0) {
break;
}
} catch (bytes memory) {
// Swallow failures, leaving all results as zero.
break;
}
}
}
function sampleBuysFromGMX(
address reader,
address vault,
address[] memory path,
uint256[] memory makerTokenAmounts
)
public
view
returns (uint256[] memory takerTokenAmounts)
{
address[] memory invertBuyPath = new address[](2);
invertBuyPath[0] = path[1];
invertBuyPath[1] = path[0];
return _sampleApproximateBuys(
ApproximateBuyQuoteOpts({
makerTokenData: abi.encode(reader, vault, invertBuyPath),
takerTokenData: abi.encode(reader, vault, path),
getSellQuoteCallback: _sampleSellForApproximateBuyFromGMX
}),
makerTokenAmounts
);
}
function _sampleSellForApproximateBuyFromGMX(
bytes memory takerTokenData,
bytes memory makerTokenData,
uint256 sellAmount
)
private
view
returns (uint256 buyAmount)
{
(address _reader, address _vault, address[] memory _path ) = abi.decode(takerTokenData, (address, address, address[]));
(bool success, bytes memory resultData) = address(this).staticcall(abi.encodeWithSelector(
this.sampleSellsFromGMX.selector,
_reader,
_vault,
_path,
_toSingleValueArray(sellAmount)
));
if(!success) {
return 0;
}
// solhint-disable-next-line indent
return abi.decode(resultData, (uint256[]))[0];
}
}