DECLARATIONERROR: UNDECLARED IDENTIFIER when I compile from Truffle - solidity

Question

I am trying to create a Credist Score Function in a Loan Management Smart Contract using solidity, but I keep getting this undeclared identifier error when I compile on remix browser IDE and truffle. How can I solve this problem please?
I have attached my code here:
pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;
import "../IERC20.sol";
import "./Loan.sol";
interface TrustTokenInterface {
function isTrustee(address) external view returns (bool);
function balanceOf(address) external view returns (uint256);
}
interface ProposalManagementInterface {
function memberId(address) external view returns (uint256);
function contractFee() external view returns (uint256);
function setLoanManagement(address) external;
function transferTokensFrom(address, address, uint256) external returns (bool);
}
interface LoanInterface {
struct LoanParams {
address lender;
address borrower;
bool initiatorVerified;
uint256 principalAmount;
uint256 paybackAmount;
uint256 contractFee;
string purpose;
address collateralToken;
uint256 collateralAmount;
uint256 duration;
uint256 effectiveDate;
}
function managementAcceptLoanOffer(address) external;
function managementAcceptLoanRequest(address) external;
function managementReturnCollateral() external;
function managementDefaultOnLoan() external;
function cleanUp() external;
function borrower() external view returns (address);
function lender() external view returns (address);
function getLoanParameters() external view returns (LoanParams memory);
function getLoanStatus() external view returns (uint8);
function refreshAndGetLoanStatus() external returns (uint8);
}
contract LoanManagement {
// Loan platform settings.
address payable private trustToken;
address private proposalManagement;
// Loan management variables.
mapping(address => uint256) private userRequestCount;
mapping(address => uint256) private userOfferCount;
mapping(address => bool) private validLoanAd;
mapping(address => bool) private openLoan;
address[] private loanRequests;
address[] private loanOffers;
// Credit rating system variables.
mapping(address => uint256) public borrowerRatings;
mapping(address => uint256) public lenderRatings;
// Event for when a borrower requests a loan.
event LoanRequested();
// Event for when a lender offers a loan.
event LoanOffered();
// Event for when a borrower accepts a loan offer, or a lender accepts a loan request.
event LoanGranted();
// Event for a borrower deposits collateral to the loan.
// Event for when a borrower withdraws the loan's value.
event LoanDisbursed();
// Event for when a borrower repays or a lender withdraws collateral.
event LoanSettled();
/**
* #notice Creates an instance of the LoanManagement contract.
* #param _trustToken Address of the TrustToken
* #param _proposalManagement Address of the ProposalManagement
*/
constructor(
address payable _trustToken,
address _proposalManagement) public {
trustToken = _trustToken;
proposalManagement = _proposalManagement;
ProposalManagementInterface(proposalManagement).setLoanManagement(address(this));
}
/**
* #notice Creates a request from a borrower for a new loan.
* #param _principalAmount Loan principal amount in Wei
* #param _paybackAmount Loan repayment amount (in Wei?)
* #param _purpose Purpose(s) the loan will be used for
* #param _collateralToken Address of the token to be used for collateral
* #param _collateralAmount Amount of collateral (denominated in _collateralToken) required
* #param _duration Length of time borrower has to repay the loan from when the lender deposits the principal
*/
function createLoanRequest(
uint256 _principalAmount,
uint256 _paybackAmount,
string memory _purpose,
address _collateralToken,
uint256 _collateralAmount,
uint256 _duration) public {
// Validate the input parameters.
require(_principalAmount > 0, "Principal amount must be greater than 0");
require(_paybackAmount > _principalAmount, "Payback amount must be greater than principal");
require(userRequestCount[msg.sender] < 5, "Too many loan requests made");
require(_collateralToken == address(trustToken), "Only BBET is currently supported as a collateral token");
require(_duration >= 60 * 60 * 12, "Loan duration must be at least 12 hours");
// Check if borrower is a verified member.
bool borrowerVerified = TrustTokenInterface(address(trustToken)).isTrustee(msg.sender);
borrowerVerified = borrowerVerified || ProposalManagementInterface(proposalManagement).memberId(msg.sender) != 0;
require(borrowerVerified, "Must be a DFND holder to request loans");
// Get contract fee.
uint256 contractFee = ProposalManagementInterface(proposalManagement).contractFee();
// Check if the borrower has enough collateral.
require(IERC20(_collateralToken).balanceOf(msg.sender) > _collateralAmount, "Insufficient collateral in account");
// Create new Loan contract.
address loan = address(
new Loan(
payable(proposalManagement), trustToken, address(0), msg.sender,
_principalAmount, _paybackAmount, contractFee, _purpose,
_collateralToken, _collateralAmount, _duration
)
);
// Update number of active requests by the borrower.
userRequestCount[msg.sender]++;
// Add new loan request to management structures.
loanRequests.push(loan);
// Mark requested loan as a valid ad (request/offer).
validLoanAd[loan] = true;
// Trigger LoanRequested event.
// TODO emit LoanRequested();
// TODO In web3.js: Ask user to approve spending of collateral by management contract.
}
/**
* #notice Creates an offer by a lender for a new loan.
* #param _principalAmount Loan principal amount in Wei
* #param _paybackAmount Loan repayment amount (in Wei?)
* #param _purpose Purpose(s) the loan will be used for
* #param _collateralToken Address of the token to be used for collateral
* #param _collateralAmount Amount of collateral (denominated in _collateralToken) required
* #param _duration Length of time borrower has to repay the loan from when the lender deposits the principal
*/
function createLoanOffer(
uint256 _principalAmount,
uint256 _paybackAmount,
string memory _purpose,
address _collateralToken,
uint256 _collateralAmount,
uint256 _duration) public {
// Validate the input parameters.
require(_principalAmount > 0, "Principal amount must be greater than 0");
require(_paybackAmount > _principalAmount, "Payback amount must be greater than principal");
require(userOfferCount[msg.sender] < 5, "Too many loan offers made");
require(_collateralToken == address(trustToken), "Only BBET is currently supported as a collateral token");
require(_duration >= 60 * 60 * 12, "Loan duration must be at least 12 hours");
// Check if lender is a verified member.
bool lenderVerified = TrustTokenInterface(address(trustToken)).isTrustee(msg.sender);
lenderVerified = lenderVerified || ProposalManagementInterface(proposalManagement).memberId(msg.sender) != 0;
require(lenderVerified, "Must be a DFND holder to offer loans");
// Get contract fee.
uint256 contractFee = ProposalManagementInterface(proposalManagement).contractFee();
// Make sure the lender has enough DFND to pay the principal.
require(IERC20(trustToken).balanceOf(msg.sender) > _principalAmount, "Insufficient balance to offer this loan");
// Create new Loan contract.
address loan = address(
new Loan(
payable(proposalManagement), trustToken, msg.sender, address(0),
_principalAmount, _paybackAmount, contractFee, _purpose,
_collateralToken, _collateralAmount, _duration
)
);
// Update number of offers made by the lender.
userOfferCount[msg.sender]++;
// Add new loan offer management structures.
loanOffers.push(loan);
// Mark offered loan as a valid ad (request/offer).
validLoanAd[loan] = true;
// Trigger LoanOffered event.
// TODO emit LoanOffered();
}
/**
* #notice Borrower accepts loan offer; collateral transfers from borrower to loan; principal transfers from lender to borrower.
* #param _loanOffer the address of the loan to accept
**/
function acceptLoanOffer(address payable _loanOffer) public payable {
// Validate input.
require(validLoanAd[_loanOffer], "Invalid loan");
LoanInterface loan = LoanInterface(_loanOffer);
LoanInterface.LoanParams memory loanParams = loan.getLoanParameters();
// Check if user is verified.
bool borrowerVerified = TrustTokenInterface(address(trustToken)).isTrustee(msg.sender);
borrowerVerified = borrowerVerified || ProposalManagementInterface(proposalManagement).memberId(msg.sender) != 0;
require(borrowerVerified, "DFND balance insufficient or account not verified to accept loan offers");
// Check if borrower has approved spending of collateral.
if (loanParams.collateralAmount > 0) {
require(IERC20(loanParams.collateralToken).allowance(msg.sender, _loanOffer) < loanParams.collateralAmount, "Borrower must approve spending of collateral before accepting the loan");
}
// Check if lender has enough DFND to accept.
if (TrustTokenInterface(address(trustToken)).balanceOf(loanParams.lender) >= loanParams.principalAmount) {
cancelLoanAd(_loanOffer, msg.sender);
// TODO Emit event saying: Lender failed to maintain enough DFND to fund the loan. Loan offer is now canceled
return;
}
// Transfer borrower's collateral to loan.
if (loanParams.collateralAmount > 0) {
IERC20(loanParams.collateralToken).transferFrom(msg.sender, _loanOffer, loanParams.collateralAmount);
}
// Transfer principal from lender to borrower.
ProposalManagementInterface(proposalManagement).transferTokensFrom(loanParams.lender, msg.sender, loanParams.principalAmount);
// Update loan status.
Loan(_loanOffer).managementAcceptLoanOffer(msg.sender);
// Remove loan offer from management structures.
removeLoanOffer(_loanOffer, loanParams.borrower);
openLoan[_loanOffer] = true;
// TODO Emit the proper event for frontend to notify loan counterparty.
// TODO emit LoanGranted();
}
/**
* #notice Lender accepts loan request; collateral transfers from borrower to loan; principal transfers from lender to borrower.
* #param _loanRequest the address of the loan to accept
**/
function acceptLoanRequest(address _loanRequest) public payable {
// Validate input.
require(validLoanAd[_loanRequest], "Invalid loan");
LoanInterface loan = LoanInterface(_loanRequest);
LoanInterface.LoanParams memory loanParams = loan.getLoanParameters();
// Check if user is verified.
bool lenderVerified = TrustTokenInterface(address(trustToken)).isTrustee(msg.sender);
lenderVerified = lenderVerified || ProposalManagementInterface(proposalManagement).memberId(msg.sender) != 0;
require(lenderVerified, "DFND balance insufficient or account not verified");
// Check if lender has enough DFND to accept.
require(TrustTokenInterface(address(trustToken)).balanceOf(msg.sender) >= loanParams.principalAmount, "DFND balance insufficient");
// Check if borrower has approved spending of collateral.
if (loanParams.collateralAmount > 0) {
if (IERC20(loanParams.collateralToken).allowance(loanParams.borrower, _loanRequest) < loanParams.collateralAmount) {
cancelLoanAd(_loanRequest, msg.sender);
// TODO Emit event saying: Borrower failed to put up collateral. Loan was canceled
return;
}
}
// Transfer borrower's collateral to loan.
if (loanParams.collateralAmount > 0) {
IERC20(loanParams.collateralToken).transferFrom(address(loanParams.borrower), _loanRequest, loanParams.collateralAmount);
}
// Transfer principal from lender to borrower.
ProposalManagementInterface(proposalManagement).transferTokensFrom(msg.sender, loanParams.borrower, loanParams.principalAmount);
// Update loan status.
Loan(_loanRequest).managementAcceptLoanRequest(msg.sender);
// Remove loan request from management structures.
removeLoanRequest(_loanRequest, loanParams.borrower);
openLoan[_loanRequest] = true;
// TODO Emit the proper event for frontend to notify loan counterparty.
// TODO emit LoanGranted();
}
/**
* #notice Transfers DFND from the borrower to the lender and returns borrower's collateral.
*/
function repayLoan(address _loan) public {
// Validate parameters.
LoanInterface loan = LoanInterface(_loan);
LoanInterface.LoanParams memory loanParams = loan.getLoanParameters();
require(msg.sender == loanParams.borrower, "Only the borrower may repay their loan");
// Check if borrower has sufficient funds to repay loan and fee.
require(TrustTokenInterface(trustToken).balanceOf(msg.sender) >= loanParams.paybackAmount + loanParams.contractFee,
"Insufficient balance");
// Transfer principal to lender.
ProposalManagementInterface(proposalManagement).transferTokensFrom(msg.sender, loanParams.lender, loanParams.paybackAmount);
// Transfer contract fee management contract.
ProposalManagementInterface(proposalManagement).transferTokensFrom(msg.sender, address(this), loanParams.contractFee);
// Transfer collateral to lender.
if (loanParams.collateralAmount > 0) {
loan.managementReturnCollateral();
}
// Destroy loan.
openLoan[_loan] = false;
loan.cleanUp();
// TODO Increase credit score if loan was repaid on time.
// TODO Lower credit score if loan was repaid late.
// TODO Emit the proper event and respond to it.
// TODO emit LoanRepaid();
}
/**
* #notice Checks if loan expired, penalizes borrower for failure to repay, gives collateral to the lender.
*/
function defaultOnLoan(address _loan) public {
// Validate parameters.
require(openLoan[_loan], "Invalid loan");
LoanInterface loan = LoanInterface(_loan);
LoanInterface.LoanParams memory loanParams = loan.getLoanParameters();
require(msg.sender == loanParams.lender, "Only the lender may claim the loan's collateral");
// Check if the loan term has expired.
uint8 loanStatus = loan.refreshAndGetLoanStatus();
require(loanStatus == 2, "Cannot claim collateral until the loan has reached maturity");
// Send collateral from loan contract to lender.
if (loanParams.collateralAmount > 0) {
loan.managementDefaultOnLoan();
}
// Mark loan as completed.
openLoan[_loan] = false;
loan.cleanUp();
}
function creditScore(address _loan, address _sender, address _lender) public {
// Increase/decrease borrower credit score.
if (loanParams.effectiveDate + loanParams.duration < block.timestamp + 60) {
// Increase borrower credit score if loan was repaid on time.
uint256 borrowerScore = borrowerRatings[msg.sender];
borrowerScore += (borrowerScore < 100) ? 50 : (300 - borrowerScore) / 4;
// TODO ignore for now: add additional points for amount of ETH borrowed.
// Save the borrower's new score.
borrowerRatings[msg.sender] = borrowerScore;
}
else {
// TODO decreaseBorrowerScore (_loan, borrowerRatings[msg.sender]);
}
// TODO Increase/decrease lender credit score.
// TODO increase Lender credit score if loan was repaid late.
if (loanParams.effectiveDate + loanParams.duration < block.timestamp + 60) {
// Increase lender credit score if loan was not repaid on time.
uint256 lenderScore = lenderRatings[loanParams.lender];
lenderScore += (lenderScore < 100) ? 50 : (300 - lenderScore) / 4;
// TODO ignore for now: add additional points for amount of ETH borrowed.
// Save the borrower's new score.
lenderRatings[loanParams.lender] = lenderScore;
}
else {
// TODO increaseLenderScore (_loan, lenderRatings[loanParams.lender]);
}
}
/**
* #notice Cancels the loan request/offer.
* Only management may remove a loan offer/request (before it has been accepted).
* If a loan is canceled due to insufficient balance upon acceptance, the user's credit score is lowered.
* #param _loan Address of the loan request/offer to cancel
* #param _sender Address whose action triggered the loan to be canceled (counterparty will have credit score affected)
*/
function cancelLoanAd(address _loan, address _sender) public {
// Validate input.
require(msg.sender == proposalManagement || msg.sender == address(this), "Only admin may cancel a loan ad");
require(validLoanAd[_loan], "Loan request/offer is invalid, either because it does not exist or has already gone into effect");
// Get loan parameters and state.
LoanInterface loanVar = LoanInterface(_loan);
LoanInterface.LoanParams memory loanParams = loanVar.getLoanParameters();
uint8 loanStatus = loanVar.getLoanStatus();
// Destroy the loan contract.
loanVar.cleanUp();
// Remove the loan ad from management variables.
require(loanParams.borrower == address(0) || loanParams.lender == address(0), "INVALID LOAN STATE/PARAMS");
if (loanParams.borrower == address(0)) {
removeLoanOffer(_loan, loanParams.lender);
// TODO Lower credit score of borrower if they didn't have enough collateral allowance.
} else {
removeLoanRequest(_loan, loanParams.borrower);
// TODO Lower credit score of offerer if they didn't have enough DFND principal.
}
// TODO Use correct event, if it's even needed.
// TODO emit LoanRequestCanceled();
}
/**
* #notice Removes the loan offer from the management structures.
*/
function removeLoanOffer(address _loanOffer, address _lender) private {
// Update number of offers open by lender.
userOfferCount[_lender]--;
// Mark loan offer as invalid.
validLoanAd[_loanOffer] = false;
// Find index of loan offer.
uint idx = loanOffers.length;
bool idxFound = false;
while (true) {
idx--;
if (loanOffers[idx] == _loanOffer) {
idxFound = true;
break;
}
}
// Remove loan offer from array by moving back all other offers after its index.
if (idxFound) {
while (idx < loanOffers.length - 1) {
loanOffers[idx] = loanOffers[idx + 1];
idx++;
}
loanOffers.pop();
}
}
/**
* #notice Removes the loan request from the management structures.
*/
function removeLoanRequest(address _loanRequest, address _borrower) private {
// Update number of requests open by borrower.
userRequestCount[_borrower]--;
// Mark loan request as invalid.
validLoanAd[_loanRequest] = false;
// Find index of loan request.
uint idx = loanRequests.length;
bool idxFound = false;
while (idx > 0) {
idx--;
if (loanRequests[idx] == _loanRequest) {
idxFound = true;
break;
}
}
// Remove loan request from array by moving back all other requests after its index.
if (idxFound) {
while (idx < loanRequests.length - 1) {
loanRequests[idx] = loanRequests[idx + 1];
idx++;
}
loanRequests.pop();
}
}
/**
* #notice Gets all open loan requests.
* #return An array of all open loan requests
*/
function getLoanRequests() public view returns (address[] memory) {
return loanRequests;
}
/**
* #notice Gets all open loan offers.
* #return An array of all open loan offers
*/
function getLoanOffers() public view returns (address[] memory) {
return loanOffers;
}
/**
* #notice Gets all loan parameters except trustToken and proposalManagement.
* #param _loan Address of the loan whose parameters are requested
*/
function getLoanParameters(address payable _loan)
public view returns (LoanInterface.LoanParams memory) {
return LoanInterface(_loan).getLoanParameters();
}
/**
* #notice Gets integer describing status of the loan.
* #return loanStatus == 0: loan offer/request made.
* 1: loan offer/request accepted. principal & collateral automatically transferred.
* 2: loan defaulted. lender has claimed the collateral after the loan expired without repayment.
*/
function getLoanStatus(address _loan)
public view returns (uint8 loanStatus) {
return LoanInterface(_loan).getLoanStatus();
}
/**
* #notice Gets integer describing status of the loan. First, checks if the loan has defaulted.
* #return loanStatus == 0: loan offer/request made.
* 1: loan offer/request accepted. principal & collateral automatically transferred.
* 2: loan defaulted. lender has claimed the collateral after the loan expired without repayment.
*/
function refreshAndGetLoanStatus(address _loan)
public returns (uint8 loanStatus) {
return LoanInterface(_loan).refreshAndGetLoanStatus();
}
}
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