MM_Redeemer.sol

//SPDX-License-Identifier: MIT
//2021, @fbsloXBT

pragma solidity ^0.8.4;

interface IUSDC {
    function transfer(address to, uint256 amount) external returns(bool);
    function transferFrom(address sender, address receiver, uint256 amount) external returns(bool);
}

interface IMM {
    function transfer(address to, uint256 amount) external returns(bool);
    function transferFrom(address sender, address receiver, uint256 amount) external returns(bool);
}

contract MM_Redeemer {
    //USDC
    IUSDC public USDC = IUSDC(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
    
    //MillionToken
    IMM public MM = IMM(0x6B4c7A5e3f0B99FCD83e9c089BDDD6c7FCe5c611);
    
    //Event
    event Redemption(address user, uint256 amount);
    event Buy(address user, uint256 amount);
    
    
    function redeem(uint256 amount) external {
        //Transfre MM from user and USDC to user
        bool mmTransfer = MM.transferFrom(msg.sender, address(this), amount);
        bool usdcTransfer = USDC.transfer(msg.sender, amount);
        
        //Make sure both transfers were successful
        require(mmTransfer && usdcTransfer, 'Transfer failed');
        
        emit Redemption(msg.sender, amount);
    }
    
    function buy(uint256 amount) external {
        //Transfer USDC from user and MM to user
        bool usdcTransfer = USDC.transferFrom(msg.sender, address(this), amount);
        bool mmTransfer = MM.transfer(msg.sender, amount);
        
        //Make sure both transfers were successful
        require(mmTransfer && usdcTransfer, 'Transfer failed');
        
        emit Buy(msg.sender, amount);        
    }
}