Alluo - Extract 3CRV Adatptor

adaptor.sol

    function executeSwap(
        address pool,
        address fromToken,
        address toToken,
        uint256 amount
    ) external payable returns (uint256) {
        ICurve3Crv pool3crv = ICurve3Crv(pool);

        if (toToken == address(token3crv)) {
            // enter 3crv pool to get 3crv token
            int128 i = indexByCoin(fromToken);
            require(i != 0, "Curve3CrvSwapAdapter: can't swap");
            uint256[3] memory amounts;
            amounts[uint256(int256(i - 1))] = amount;

            pool3crv.add_liquidity(amounts, 0);

            return token3crv.balanceOf(address(this));
        } else if (fromToken == address(token3crv)) {
            // exit 3crv pool to get stable
            int128 i = indexByCoin(toToken);
            require(i != 0, "Curve3CrvSwapAdapter: can't swap");

            pool3crv.remove_liquidity_one_coin(amount, i - 1, 0);

            return IERC20(toToken).balanceOf(address(this));
        } else {
            revert("Curve3CrvSwapAdapter: can't swap");
        }
    }