ERC-7444: 时间锁到期时间

// SPDX-License-Identifier: CC0-1.0

pragma solidity ^0.8.0;

interface ERC-7444 {
    /
     * @notice 这个函数返回 `id` 指定的时间锁解锁的时间戳
     * @param  id 描述特定时间锁的标识符
     * @return maturity 时间锁解锁的时间戳
     */
    function getMaturity(bytes32 id)
        external
        view
        returns (uint256 maturity);

}

// SPDX-License-Identifier: CC0-1.0

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract LockedERC20ExampleContract implements ERC-7444{
    ERC20 public immutable token;
    uint256 public totalLocked;

    //Timelock struct
    struct TimeLock {
        address owner;
        uint256 amount;
        uint256 maturity;
        bytes32 lockId;
    }

    //maps lockId to balance of the lock
    mapping(bytes32 => TimeLock) public idToLock;    

    function constructor(
        address _token,
    ) public {
        token = ERC20(_token);
    }

    //Maturity is not appropriate
    error LockPeriodOngoing();
    error InvalidReceiver();
    error TransferFailed();

    /// @dev Deposit tokens to be locked in the requested locking period
    /// @param amount The amount of tokens to deposit
    /// @param lockingPeriod length of locking period for the tokens to be locked
    function deposit(uint256 amount, uint256 lockingPeriod) external returns (bytes32 lockId) {
        uint256 maturity = block.timestamp + lockingPeriod;
        lockId = keccack256(abi.encode(msg.sender, amount, maturity));

        require(idToLock[lockId].maturity == 0, "lock already exists");

        if (!token.transferFrom(msg.sender, address(this), amount)) {
            revert TransferFailed();
        }

        TimeLock memory newLock = TimeLock(msg.sender, amount, maturity, lockedId);

        totalLocked += amount;

        idToLock[lockId] = newLock;
        
    }

    /// @dev Withdraw tokens in the lock after the end of the locking period
    /// @param lockId id of the lock that user have deposited in
    function withdraw(bytes32 lockId) external {
        TimeLock memory lock = idToLock[lockId];

        if (msg.sender != lock.owner) {
            revert InvalidReceiver();
        }

        if (block.timestamp > lock.maturity) {
            revert LockPeriodOngoing();
        }

        totalLocked -= lock.amount;

        //State cleanup
        delete idToLock[lockId];

        if (!token.transfer(msg.sender, lock.amount)) {
            revert TransferFailed();
        }

    }

    function getMaturity(bytes32 id) external view returns (uint256 maturity) {
        return idToLock[id].maturity;
    }
}