Lease Smart Contract

Overview

The Lease Agreement Contract is responsible for managing lease agreements between property owners and lessees. It ensures that lease agreements are created, terminated, and enforced according to the agreed-upon terms.

Key features of the Lease Agreement Contract:

• Stores references to DeedNFT and LeaseNFT contracts.

• Includes a mapping to store active lease agreements.

• Provides functions for creating, terminating, and updating lease agreements.

• Implements a function to verify the ownership of a DeedNFT before creating a lease agreement.

Contract Data Structure

The Lease Agreement Contract manages lease agreements using a struct called Lease, which includes the following information:

• LeaseNFT token ID

• DeedNFT token ID

• Lessee and lessor Ethereum addresses

• Lease start and end dates

• Rent amount and payment frequency

• Security deposit amount

• Lease status (active or terminated)

Core Contract Functions

The Lease Agreement Contract includes functions for creating, updating, and terminating lease agreements. The functions can only be called by the contract owner or authorized addresses.

createLease: Creates a new lease agreement and mints a corresponding LeaseNFT.

function createLease(
    address _lessee,
    uint256 _startDate,
    uint256 _endDate,
    uint256 _rentAmount,
    uint256 _securityDeposit,
    uint256 _propertyTokenId // Add the _propertyTokenId parameter
) external {
    require(_lessee != address(0), "LeaseAgreement: Invalid lessee address");
    require(_startDate < _endDate, "LeaseAgreement: Invalid start and end dates");
    require(verifyDeedOwnership(msg.sender, _propertyTokenId), "LeaseAgreement: Lessor must own the property NFT");
    uint256 leaseId = leaseCounter;
    leaseCounter++;

    Lease storage lease = leases[leaseId];
    lease.lessor = msg.sender;
    lease.lessee = _lessee;
    lease.startDate = _startDate;
    lease.endDate = _endDate;
    lease.rentAmount = _rentAmount;
    lease.securityDeposit = _securityDeposit;
    lease.rentDueDate = _startDate + 30 days;
    lease.unpaidMonths = 0;
    lease.extensionCount = 0;
    lease.propertyTokenId = _propertyTokenId; // Set the propertyTokenId in the Lease struct

    leaseNFT.mintToken(msg.sender, leaseId); // Add a custom error message for debugging
    require(true, "createLease: Lease created successfully");
}

updateLease: Updates an existing lease agreement's information.

function updateLease(
    uint256 _leaseId,
    uint256 _newStartDate,
    uint256 _newEndDate,
    uint256 _newLeaseAmount
) public {
    LeaseAgreement storage lease = leaseAgreements[_leaseId];

    // Check that the caller is the lessor
    require(msg.sender == lease.lessor, "Only the lessor can update the lease");

    // Update the lease fields
    lease.startDate = _newStartDate;
    lease.endDate = _newEndDate;
    lease.leaseAmount = _newLeaseAmount;
}

terminateLease: Terminates a lease agreement and burns the corresponding LeaseNFT.

function terminateLease(uint256 leaseId) public {
        Lease storage lease = leases[leaseId];
        require(msg.sender == lease.lessor || msg.sender == lease.lessee, "Only lessor or lessee can terminate the lease");
        require(block.timestamp >= lease.startDate, "Lease has not started yet");

        if (lease.securityDeposit > 0) {
            xDai.transfer(lease.lessee, lease.securityDeposit);
        }

        uint256 remainingBalance = xDai.balanceOf(address(this));
        if (remainingBalance > 0) {
            xDai.transfer(lease.lessor, remainingBalance);
        }

        leaseNFT.burn(leaseId);
    }