NFTFI Private contract
LoanData.sol
// SPDX-License-Identifier: BUSL-1.1
 
pragma solidity 0.8.4;
 
/**
 * @title  LoanData
 * @author NFTfi
 * @notice An interface containg the main Loan struct shared by Direct Loans types.
 */
interface LoanData {
    /* ********** */
    /* DATA TYPES */
    /* ********** */
 
    /**
     * @notice The main Loan Terms struct. This data is saved upon loan creation.
     *
     * @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
     * for this loan.
     * @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
     * the loan, measured in loanERC20Denomination's smallest units.
     * @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
     * collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
     * to pay this amount to retrieve their collateral, regardless of whether they repay early.
     * @param nftCollateralContract - The address of the the NFT collateral contract.
     * @param nftCollateralWrapper - The NFTfi wrapper of the NFT collateral contract.
     * @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
     * loan. The NFT is stored within this contract during the duration of the loan.
     * @param loanStartTime - The block.timestamp when the loan first began (measured in seconds).
     * @param loanDuration - The amount of time (measured in seconds) that can elapse before the lender can liquidate
     * the loan and seize the underlying collateral NFT.
     * @param loanInterestRateForDurationInBasisPoints - This is the interest rate (measured in basis points, e.g.
     * hundreths of a percent) for the loan, that must be repaid pro-rata by the borrower at the conclusion of the loan
     * or risk seizure of their nft collateral. Note if the type of the loan is fixed then this value  is not used and
     * is irrelevant so it should be set to 0.
     * @param loanAdminFeeInBasisPoints - The percent (measured in basis points) of the interest earned that will be
     * taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
     * attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
     * earned.
     * @param borrower
     */
    struct LoanTerms {
        uint256 loanPrincipalAmount;
        uint256 maximumRepaymentAmount;
        uint256 nftCollateralId;
        address loanERC20Denomination;
        uint32 loanDuration;
        uint16 loanInterestRateForDurationInBasisPoints;
        uint16 loanAdminFeeInBasisPoints;
        address nftCollateralWrapper;
        uint64 loanStartTime;
        address nftCollateralContract;
        address borrower;
    }
 
    /**
     * @notice Some extra Loan's settings struct. This data is saved upon loan creation.
     * We need this to avoid stack too deep errors.
     *
     * @param revenueSharePartner - The address of the partner that will receive the revenue share.
     * @param revenueShareInBasisPoints - The percent (measured in basis points) of the admin fee amount that will be
     * taken as a revenue share for a t
     * @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
     * be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.he partner, at the moment
     * the loan is begun.
     */
    struct LoanExtras {
        address revenueSharePartner;
        uint16 revenueShareInBasisPoints;
        uint16 referralFeeInBasisPoints;
    }
 
    /**
     * @notice The offer made by the lender. Used as parameter on both acceptOffer (initiated by the borrower) and
     * acceptListing (initiated by the lender).
     *
     * @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
     * for this loan.
     * @param loanPrincipalAmount - The original sum of money transferred from lender to borrower at the beginning of
     * the loan, measured in loanERC20Denomination's smallest units.
     * @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
     *  collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always
     * have to pay this amount to retrieve their collateral, regardless of whether they repay early.
     * @param nftCollateralContract - The address of the ERC721 contract of the NFT collateral.
     * @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
     * loan. The NFT is stored within this contract during the duration of the loan.
     * @param referrer - The address of the referrer who found the lender matching the listing, Zero address to signal
     * this there is no referrer.
     * @param loanDuration - The amount of time (measured in seconds) that can elapse before the lender can liquidate
     * the loan and seize the underlying collateral NFT.
     * @param loanAdminFeeInBasisPoints - The percent (measured in basis points) of the interest earned that will be
     * taken as a fee by the contract admins when the loan is repaid. The fee is stored in the loan struct to prevent an
     * attack where the contract admins could adjust the fee right before a loan is repaid, and take all of the interest
     * earned.
     */
    struct Offer {
        uint256 loanPrincipalAmount;
        uint256 maximumRepaymentAmount;
        uint256 nftCollateralId;
        address nftCollateralContract;
        uint32 loanDuration;
        uint16 loanAdminFeeInBasisPoints;
        address loanERC20Denomination;
        address referrer;
    }
 
    /**
     * @notice Signature related params. Used as parameter on both acceptOffer (containing borrower signature) and
     * acceptListing (containing lender signature).
     *
     * @param signer - The address of the signer. The borrower for `acceptOffer` the lender for `acceptListing`.
     * @param nonce - The nonce referred here is not the same as an Ethereum account's nonce.
     * We are referring instead to a nonce that is used by the lender or the borrower when they are first signing
     * off-chain NFTfi orders. These nonce can be any uint256 value that the user has not previously used to sign an
     * off-chain order. Each nonce can be used at most once per user within NFTfi, regardless of whether they are the
     * lender or the borrower in that situation. This serves two purposes:
     * - First, it prevents replay attacks where an attacker would submit a user's off-chain order more than once.
     * - Second, it allows a user to cancel an off-chain order by calling NFTfi.cancelLoanCommitmentBeforeLoanHasBegun()
     * , which marks the nonce as used and prevents any future loan from using the user's off-chain order that contains
     * that nonce.
     * @param expiry - Date when the signature expires
     * @param signature - The ECDSA signature of the borrower or the lender, obtained off-chain ahead of time, signing
     * the following combination of parameters:
     * - Borrower
     *   - ListingTerms.loanERC20Denomination,
     *   - ListingTerms.minLoanPrincipalAmount,
     *   - ListingTerms.maxLoanPrincipalAmount,
     *   - ListingTerms.nftCollateralContract,
     *   - ListingTerms.nftCollateralId,
     *   - ListingTerms.revenueSharePartner,
     *   - ListingTerms.minLoanDuration,
     *   - ListingTerms.maxLoanDuration,
     *   - ListingTerms.maxInterestRateForDurationInBasisPoints,
     *   - ListingTerms.referralFeeInBasisPoints,
     *   - Signature.signer,
     *   - Signature.nonce,
     *   - Signature.expiry,
     *   - address of the loan type contract
     *   - chainId
     * - Lender:
     *   - Offer.loanERC20Denomination
     *   - Offer.loanPrincipalAmount
     *   - Offer.maximumRepaymentAmount
     *   - Offer.nftCollateralContract
     *   - Offer.nftCollateralId
     *   - Offer.referrer
     *   - Offer.loanDuration
     *   - Offer.loanAdminFeeInBasisPoints
     *   - Signature.signer,
     *   - Signature.nonce,
     *   - Signature.expiry,
     *   - address of the loan type contract
     *   - chainId
     */
    struct Signature {
        uint256 nonce;
        uint256 expiry;
        address signer;
        bytes signature;
    }
 
    /**
     * @notice Some extra parameters that the borrower needs to set when accepting an offer.
     *
     * @param revenueSharePartner - The address of the partner that will receive the revenue share.
     * @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
     * be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
     */
    struct BorrowerSettings {
        address revenueSharePartner;
        uint16 referralFeeInBasisPoints;
    }
 
    /**
     * @notice Terms the borrower set off-chain and is willing to accept automatically when fulfiled by a lender's
     * offer.
     *
     * @param loanERC20Denomination - The address of the ERC20 contract of the currency being used as principal/interest
     * for this loan.
     * @param minLoanPrincipalAmount - The minumum sum of money transferred from lender to borrower at the beginning of
     * the loan, measured in loanERC20Denomination's smallest units.
     * @param maxLoanPrincipalAmount - The  sum of money transferred from lender to borrower at the beginning of
     * the loan, measured in loanERC20Denomination's smallest units.
     * @param maximumRepaymentAmount - The maximum amount of money that the borrower would be required to retrieve their
     * collateral, measured in the smallest units of the ERC20 currency used for the loan. The borrower will always have
     * to pay this amount to retrieve their collateral, regardless of whether they repay early.
     * @param nftCollateralContract - The address of the ERC721 contract of the NFT collateral.
     * @param nftCollateralId - The ID within the NFTCollateralContract for the NFT being used as collateral for this
     * loan. The NFT is stored within this contract during the duration of the loan.
     * @param revenueSharePartner - The address of the partner that will receive the revenue share.
     * @param minLoanDuration - The minumum amount of time (measured in seconds) that can elapse before the lender can
     * liquidate the loan and seize the underlying collateral NFT.
     * @param maxLoanDuration - The maximum amount of time (measured in seconds) that can elapse before the lender can
     * liquidate the loan and seize the underlying collateral NFT.
     * @param maxInterestRateForDurationInBasisPoints - This is maximum the interest rate (measured in basis points,
     * e.g. hundreths of a percent) for the loan.
     * @param referralFeeInBasisPoints - The percent (measured in basis points) of the loan principal amount that will
     * be taken as a fee to pay to the referrer, 0 if the lender is not paying referral fee.
     */
    struct ListingTerms {
        uint256 minLoanPrincipalAmount;
        uint256 maxLoanPrincipalAmount;
        uint256 nftCollateralId;
        address nftCollateralContract;
        uint32 minLoanDuration;
        uint32 maxLoanDuration;
        uint16 maxInterestRateForDurationInBasisPoints;
        uint16 referralFeeInBasisPoints;
        address revenueSharePartner;
        address loanERC20Denomination;
    }
}