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contracts...Quests.sol

pragma solidity >=0.7.0 <0.9.0;


interface cETH {
    
    // define functions of COMPOUND we'll be using
    
    function mint() external payable; // to deposit to compound
    function redeem(uint redeemTokens) external returns (uint); // to withdraw from compound
    
    //following 2 functions to determine how much you'll be able to withdraw
    function exchangeRateStored() external view returns (uint); 
    function balanceOf(address owner) external view returns (uint256 balance);
}


contract SmartBankAccount {


    uint totalContractBalance = 0;
    
    address COMPOUND_CETH_ADDRESS = 0x859e9d8a4edadfEDb5A2fF311243af80F85A91b8;
    cETH ceth = cETH(COMPOUND_CETH_ADDRESS);
    
    function getContractBalance() public view returns(uint){
        return address(this).balance;
    }
    
    mapping(address => uint) ethBalances;
    mapping(address => uint) cethBalances;
    mapping(address => uint) depositTimestamps;
    event myVAr(uint);
    
    function addBalance() public payable {
        ethBalances[msg.sender] += msg.value;
    }
    function deposit(uint amount, bool percent) public {
        // allow user to input percentage amount instead.
        if (percent) {
            amount = (ethBalances[msg.sender]*amount)/100;
        }
        require(amount <= ethBalances[msg.sender], 'insufficient balance to invest');
        uint256 cEthOfContractBeforeMinting = ceth.balanceOf(address(this)); //this refers to the current contract
        
        // send ethers to mint()
        ethBalances[msg.sender] -= amount;
        ceth.mint{value: amount}();
        
        uint256 cEthOfContractAfterMinting = ceth.balanceOf(address(this)); // updated balance after minting
        
        uint cEthOfUser = cEthOfContractAfterMinting - cEthOfContractBeforeMinting; // the difference is the amount that has been created by the mint() function
        cethBalances[msg.sender] += cEthOfUser;
    }
    
    function getBalance() public view returns(uint256) {
        return ceth.balanceOf(address(this));
    }
    
    function getEthBalance() public view returns(uint256) {
        return ethBalances[msg.sender];
    }
    
    function getCethBalance(address userAddress) public view returns(uint256) {
        return cethBalances[userAddress];
    }
    
    function getExchangeRate() public view returns(uint256){
        return ceth.exchangeRateStored() / 1e10;
    }

    function withdraw(uint amount, bool percent) public returns (bool) {
        uint rate = getExchangeRate();
        uint withdraw_value;
        if (percent) {
            withdraw_value = (cethBalances[msg.sender]*amount)/100;
        }else {
            withdraw_value = (amount*1e8)/rate;
        }
        emit myVAr(withdraw_value);
        require(cethBalances[msg.sender] >= withdraw_value, 'insufficient');
        cethBalances[msg.sender] -= withdraw_value;
        uint totalBefore = getContractBalance();
        require(ceth.redeem(withdraw_value) == 0, 'failed');
        uint balanceAfter = getContractBalance();
        // TODO: keep some percentage profit.
        payable(msg.sender).transfer(balanceAfter - totalBefore);
        return true;
    }

    function addMoneyToContract() public payable {
        totalContractBalance += msg.value;
    }

    receive() external payable{

    }

    
}