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Add first draft of swapAndRepay without using flash loans

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This commit is contained in:
Gerardo Nardelli 2020-11-24 12:11:13 -03:00
parent 43d05c2bdf
commit 50e5ea907b
2 changed files with 54 additions and 9 deletions
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29
contracts/adapters/BaseUniswapAdapter.sol
View File

@ -73,7 +73,7 @@ contract BaseUniswapAdapter {
view view
returns (uint256, uint256, uint256, uint256) returns (uint256, uint256, uint256, uint256)
{ {
AmountCalc memory results = _getAmountsOut(reserveIn, reserveOut, amountIn); AmountCalc memory results = _getAmountsOutData(reserveIn, reserveOut, amountIn);
return ( return (
results.calculatedAmount, results.calculatedAmount,
@ -98,7 +98,7 @@ contract BaseUniswapAdapter {
view view
returns (uint256, uint256, uint256, uint256) returns (uint256, uint256, uint256, uint256)
{ {
AmountCalc memory results = _getAmountsIn(reserveIn, reserveOut, amountOut); AmountCalc memory results = _getAmountsInData(reserveIn, reserveOut, amountOut);
return ( return (
results.calculatedAmount, results.calculatedAmount,
@ -291,7 +291,7 @@ contract BaseUniswapAdapter {
* uint256 In amount of reserveIn value denominated in USD (8 decimals) * uint256 In amount of reserveIn value denominated in USD (8 decimals)
* uint256 Out amount of reserveOut value denominated in USD (8 decimals) * uint256 Out amount of reserveOut value denominated in USD (8 decimals)
*/ */
function _getAmountsOut(address reserveIn, address reserveOut, uint256 amountIn) internal view returns (AmountCalc memory) { function _getAmountsOutData(address reserveIn, address reserveOut, uint256 amountIn) internal view returns (AmountCalc memory) {
// Subtract flash loan fee // Subtract flash loan fee
uint256 finalAmountIn = amountIn.sub(amountIn.mul(FLASHLOAN_PREMIUM_TOTAL).div(10000)); uint256 finalAmountIn = amountIn.sub(amountIn.mul(FLASHLOAN_PREMIUM_TOTAL).div(10000));
@ -328,12 +328,8 @@ contract BaseUniswapAdapter {
* uint256 In amount of reserveIn value denominated in USD (8 decimals) * uint256 In amount of reserveIn value denominated in USD (8 decimals)
* uint256 Out amount of reserveOut value denominated in USD (8 decimals) * uint256 Out amount of reserveOut value denominated in USD (8 decimals)
*/ */
function _getAmountsIn(address reserveIn, address reserveOut, uint256 amountOut) internal view returns (AmountCalc memory) { function _getAmountsInData(address reserveIn, address reserveOut, uint256 amountOut) internal view returns (AmountCalc memory) {
address[] memory path = new address[](2); uint256[] memory amounts = _getAmountsIn(reserveIn, reserveOut, amountOut);
path[0] = reserveIn;
path[1] = reserveOut;
uint256[] memory amounts = UNISWAP_ROUTER.getAmountsIn(amountOut, path);
// Add flash loan fee // Add flash loan fee
uint256 finalAmountIn = amounts[0].add(amounts[0].mul(FLASHLOAN_PREMIUM_TOTAL).div(10000)); uint256 finalAmountIn = amounts[0].add(amounts[0].mul(FLASHLOAN_PREMIUM_TOTAL).div(10000));
@ -353,4 +349,19 @@ contract BaseUniswapAdapter {
_calcUsdValue(reserveOut, amountOut, reserveOutDecimals) _calcUsdValue(reserveOut, amountOut, reserveOutDecimals)
); );
} }
/**
* @dev Calculates the input asset amount required to buy the given output asset amount
* @param reserveIn Address of the asset to be swap from
* @param reserveOut Address of the asset to be swap to
* @param amountOut Amount of reserveOut
* @return uint256[] amounts Array containing the amountIn and amountOut for a swap
*/
function _getAmountsIn(address reserveIn, address reserveOut, uint256 amountOut) internal view returns (uint256[] memory) {
address[] memory path = new address[](2);
path[0] = reserveIn;
path[1] = reserveOut;
return UNISWAP_ROUTER.getAmountsIn(amountOut, path);
}
} }

34
contracts/adapters/UniswapRepayAdapter.sol
View File

@ -76,6 +76,40 @@ contract UniswapRepayAdapter is BaseUniswapAdapter, IFlashLoanReceiver {
return true; return true;
} }
function swapAndRepay(
address collateralAsset,
address debtAsset,
uint256 collateralAmount,
uint256 debtRepayAmount,
uint256 debtRateMode,
PermitSignature calldata permitSignature
) external {
ReserveLogic.ReserveData memory reserveData = _getReserveData(collateralAsset);
if (collateralAsset != debtAsset) {
// Get exact collateral needed for the swap to avoid leftovers
uint256[] memory amounts = _getAmountsIn(collateralAsset, debtAsset, debtRepayAmount);
require(amounts[0] <= collateralAmount, 'slippage too high');
// Pull aTokens from user
_pullAToken(collateralAsset, reserveData.aTokenAddress, msg.sender, amounts[0], permitSignature);
// Swap collateral for debt asset
_swapTokensForExactTokens(collateralAsset, debtAsset, amounts[0], debtRepayAmount);
} else {
// Pull aTokens from user
_pullAToken(collateralAsset, reserveData.aTokenAddress, msg.sender, debtRepayAmount, permitSignature);
}
// Repay debt
IERC20(debtAsset).approve(address(POOL), debtRepayAmount);
POOL.repay(debtAsset, debtRepayAmount, debtRateMode, msg.sender);
// In the case the repay amount provided exceeded the actual debt, send the leftovers to the user
_sendLeftovers(debtAsset, msg.sender);
}
/** /**
* @dev Perform the repay of the debt, pulls the initiator collateral and swaps to repay the flash loan * @dev Perform the repay of the debt, pulls the initiator collateral and swaps to repay the flash loan
* *