MeetupLoanWithRepayment.sol

pragma solidity 0.6.1;

interface MoneyToken {
    function transferFrom(address _from, address _to, uint256 _value) external returns (bool success);
}

contract Loan {
    mapping(address => uint256) public loanRegistry;
    address owner;
    address public ngntTokenAddress;

    constructor(address ownerAddress, address erc20TokenAddress) public {
        owner = ownerAddress;
        ngntTokenAddress = erc20TokenAddress;
    }
    
    function sendLoan(uint256 amount, address payable recipientsAddress) external {
        // ensure we are not loaning negative value
        require(amount != 0, "Loaning zero value wrong");
        require(msg.sender == owner, "You are not owner");
        
        // if we have loaned recipient previously update the loanRegistry
        uint256 currentValue = loanRegistry[recipientsAddress];
        loanRegistry[recipientsAddress] = currentValue + amount;
        
        // transfer actual money token
        MoneyToken ngntToken = MoneyToken(ngntTokenAddress);
        require(ngntToken.transferFrom(owner, recipientsAddress, amount), "Failed to transfer loan to receipient");
    }
    
    function repayLoan(uint256 amount) external {
        // check amount is not zero
        require(amount != 0, "Zero repayment not allowed");
        
        // update loan registry
        uint256 currentValue = loanRegistry[msg.sender];
        require(currentValue > amount, 'You are repaying too much');
        loanRegistry[msg.sender] = currentValue - amount;
        
        // transfer money from sender to owners account
        MoneyToken ngntToken = MoneyToken(ngntTokenAddress);
        require(ngntToken.transferFrom(msg.sender, owner, amount), "Failed to transfer repayment");
        
        // above will fail if msg.sender has not called
        // ngntToken.approve(address(this), amount);
    }
    
    
    function sendLoanEth(address payable recipientsAddress) payable external {
        // ensure we are not loaning negative value
        require(msg.value != 0, "Loaning zero value wrong");
        require(msg.sender == owner, "You are not owner");
        
        // if we have loaned recipient previously update the loanRegistry
        uint256 currentValue = loanRegistry[recipientsAddress];
        loanRegistry[recipientsAddress] = currentValue + msg.value;
        
        // transfer actual eth token
        recipientsAddress.transfer(msg.value);
    }
    
    function repayLoanEth() payable external {
        // check amount is not zero
        require(msg.value != 0, "Zero repayment not allowed");
        
        // update loan registry
        uint256 currentValue = loanRegistry[msg.sender];
        require(currentValue > msg.value, 'You are repaying too much');
        loanRegistry[msg.sender] = currentValue - msg.value;
    }
}