// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IVotingEscrow {
    function create_lock_for(address addr, uint value, uint unlockTime) external;
}

contract LockProxy {
    struct PreLock {
        address account;
        uint amount;
        uint unlockTime;
    }

    event CreatePreLock(uint preLockId, address account, uint amount);
    event Lock(uint preLockId, address locker, uint amount, uint startTime);

    IERC20 public token;
    IVotingEscrow public ve;

    mapping (uint => PreLock) preLocks;
    uint nextPreLockId;

    constructor(
        IERC20 token_,
        IVotingEscrow ve_
    ) {
        token = token_;
        ve = ve_;
    }

    function preLockFor(address account_, uint amount_) external {
        token.transferFrom(msg.sender, address(this), amount_);

        preLocks[nextPreLockId] = PreLock({
            account: account_,
            amount: amount_,
            unlockTime: 0
        });

        emit CreatePreLock(nextPreLockId, account_, amount_);
        nextPreLockId++;
    }

    function activeLock(uint preLockId_, uint unlockTime_) external {
        PreLock memory preLock = preLocks[preLockId_];
        require(msg.sender == preLock.account, "!locker");
        require(preLock.unlockTime == 0, "already locked");

        token.approve(address(ve), preLock.amount);
        ve.create_lock_for(preLock.account, preLock.amount, unlockTime_);

        preLocks[preLockId_].unlockTime = unlockTime_;
        emit Lock(preLockId_, msg.sender, preLock.amount, unlockTime_);
    }
}

{
  "compilationTarget": {
    "contracts/LockProxy.sol": "LockProxy"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}