DelayedWithdrawalRouter.sol

// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.12;

import "@openzeppelin-upgrades/contracts/proxy/utils/Initializable.sol";
import "@openzeppelin-upgrades/contracts/access/OwnableUpgradeable.sol";
import "@openzeppelin-upgrades/contracts/security/ReentrancyGuardUpgradeable.sol";
import "../interfaces/IEigenPodManager.sol";
import "../interfaces/IDelayedWithdrawalRouter.sol";
import "../permissions/Pausable.sol";

contract DelayedWithdrawalRouter is
    Initializable,
    OwnableUpgradeable,
    ReentrancyGuardUpgradeable,
    Pausable,
    IDelayedWithdrawalRouter
{
    // index for flag that pauses withdrawals (i.e. 'delayedWithdrawal claims') when set
    uint8 internal constant PAUSED_DELAYED_WITHDRAWAL_CLAIMS = 0;

    /**
     * @notice Delay enforced by this contract for completing any delayedWithdrawal. Measured in blocks, and adjustable by this contract's owner,
     * up to a maximum of `MAX_WITHDRAWAL_DELAY_BLOCKS`. Minimum value is 0 (i.e. no delay enforced).
     */
    uint256 public withdrawalDelayBlocks;
    // the number of 12-second blocks in 30 days (60 * 60 * 24 * 30 / 12 = 216,000)
    uint256 public constant MAX_WITHDRAWAL_DELAY_BLOCKS = 216000;

    /// @notice The EigenPodManager contract of EigenLayer.
    IEigenPodManager public immutable eigenPodManager;

    /// @notice Mapping: user => struct storing all delayedWithdrawal info. Marked as internal with an external getter function named `userWithdrawals`
    mapping(address => UserDelayedWithdrawals) internal _userWithdrawals;

    /// @notice Modifier used to permission a function to only be called by the EigenPod of the specified `podOwner`
    modifier onlyEigenPod(address podOwner) {
        require(
            address(eigenPodManager.getPod(podOwner)) == msg.sender,
            "DelayedWithdrawalRouter.onlyEigenPod: not podOwner's EigenPod"
        );
        _;
    }

    constructor(IEigenPodManager _eigenPodManager) {
        require(
            address(_eigenPodManager) != address(0),
            "DelayedWithdrawalRouter.constructor: _eigenPodManager cannot be zero address"
        );
        eigenPodManager = _eigenPodManager;
        _disableInitializers();
    }

    function initialize(
        address initOwner,
        IPauserRegistry _pauserRegistry,
        uint256 initPausedStatus,
        uint256 _withdrawalDelayBlocks
    ) external initializer {
        _transferOwnership(initOwner);
        _initializePauser(_pauserRegistry, initPausedStatus);
        _setWithdrawalDelayBlocks(_withdrawalDelayBlocks);
    }

    /**
     * @notice Creates a delayed withdrawal for `msg.value` to the `recipient`.
     * @dev Only callable by the `podOwner`'s EigenPod contract.
     */
    function createDelayedWithdrawal(
        address podOwner,
        address recipient
    ) external payable onlyEigenPod(podOwner) onlyWhenNotPaused(PAUSED_DELAYED_WITHDRAWAL_CLAIMS) {
        require(
            recipient != address(0),
            "DelayedWithdrawalRouter.createDelayedWithdrawal: recipient cannot be zero address"
        );
        uint224 withdrawalAmount = uint224(msg.value);
        if (withdrawalAmount != 0) {
            DelayedWithdrawal memory delayedWithdrawal = DelayedWithdrawal({
                amount: withdrawalAmount,
                blockCreated: uint32(block.number)
            });
            _userWithdrawals[recipient].delayedWithdrawals.push(delayedWithdrawal);
            emit DelayedWithdrawalCreated(
                podOwner,
                recipient,
                withdrawalAmount,
                _userWithdrawals[recipient].delayedWithdrawals.length - 1
            );
        }
    }

    /**
     * @notice Called in order to withdraw delayed withdrawals made to the `recipient` that have passed the `withdrawalDelayBlocks` period.
     * @param recipient The address to claim delayedWithdrawals for.
     * @param maxNumberOfDelayedWithdrawalsToClaim Used to limit the maximum number of delayedWithdrawals to loop through claiming.
     * @dev
     *      WARNING: Note that the caller of this function cannot control where the funds are sent, but they can control when the
     *              funds are sent once the withdrawal becomes claimable.
     */
    function claimDelayedWithdrawals(
        address recipient,
        uint256 maxNumberOfDelayedWithdrawalsToClaim
    ) external nonReentrant onlyWhenNotPaused(PAUSED_DELAYED_WITHDRAWAL_CLAIMS) {
        _claimDelayedWithdrawals(recipient, maxNumberOfDelayedWithdrawalsToClaim);
    }

    /**
     * @notice Called in order to withdraw delayed withdrawals made to the caller that have passed the `withdrawalDelayBlocks` period.
     * @param maxNumberOfDelayedWithdrawalsToClaim Used to limit the maximum number of delayedWithdrawals to loop through claiming.
     */
    function claimDelayedWithdrawals(
        uint256 maxNumberOfDelayedWithdrawalsToClaim
    ) external nonReentrant onlyWhenNotPaused(PAUSED_DELAYED_WITHDRAWAL_CLAIMS) {
        _claimDelayedWithdrawals(msg.sender, maxNumberOfDelayedWithdrawalsToClaim);
    }

    /// @notice Owner-only function for modifying the value of the `withdrawalDelayBlocks` variable.
    function setWithdrawalDelayBlocks(uint256 newValue) external onlyOwner {
        _setWithdrawalDelayBlocks(newValue);
    }

    /// @notice Getter function for the mapping `_userWithdrawals`
    function userWithdrawals(address user) external view returns (UserDelayedWithdrawals memory) {
        return _userWithdrawals[user];
    }

    /// @notice Getter function to get all delayedWithdrawals of the `user`
    function getUserDelayedWithdrawals(address user) external view returns (DelayedWithdrawal[] memory) {
        uint256 delayedWithdrawalsCompleted = _userWithdrawals[user].delayedWithdrawalsCompleted;
        uint256 totalDelayedWithdrawals = _userWithdrawals[user].delayedWithdrawals.length;
        uint256 userDelayedWithdrawalsLength = totalDelayedWithdrawals - delayedWithdrawalsCompleted;
        DelayedWithdrawal[] memory userDelayedWithdrawals = new DelayedWithdrawal[](userDelayedWithdrawalsLength);
        for (uint256 i = 0; i < userDelayedWithdrawalsLength; i++) {
            userDelayedWithdrawals[i] = _userWithdrawals[user].delayedWithdrawals[delayedWithdrawalsCompleted + i];
        }
        return userDelayedWithdrawals;
    }

    /// @notice Getter function to get all delayedWithdrawals that are currently claimable by the `user`
    function getClaimableUserDelayedWithdrawals(address user) external view returns (DelayedWithdrawal[] memory) {
        uint256 delayedWithdrawalsCompleted = _userWithdrawals[user].delayedWithdrawalsCompleted;
        uint256 totalDelayedWithdrawals = _userWithdrawals[user].delayedWithdrawals.length;
        uint256 userDelayedWithdrawalsLength = totalDelayedWithdrawals - delayedWithdrawalsCompleted;

        uint256 firstNonClaimableWithdrawalIndex = userDelayedWithdrawalsLength;

        for (uint256 i = 0; i < userDelayedWithdrawalsLength; i++) {
            DelayedWithdrawal memory delayedWithdrawal = _userWithdrawals[user].delayedWithdrawals[
                delayedWithdrawalsCompleted + i
            ];
            // check if delayedWithdrawal can be claimed. break the loop as soon as a delayedWithdrawal cannot be claimed
            if (block.number < delayedWithdrawal.blockCreated + withdrawalDelayBlocks) {
                firstNonClaimableWithdrawalIndex = i;
                break;
            }
        }
        uint256 numberOfClaimableWithdrawals = firstNonClaimableWithdrawalIndex;
        DelayedWithdrawal[] memory claimableDelayedWithdrawals = new DelayedWithdrawal[](numberOfClaimableWithdrawals);

        if (numberOfClaimableWithdrawals != 0) {
            for (uint256 i = 0; i < numberOfClaimableWithdrawals; i++) {
                claimableDelayedWithdrawals[i] = _userWithdrawals[user].delayedWithdrawals[
                    delayedWithdrawalsCompleted + i
                ];
            }
        }
        return claimableDelayedWithdrawals;
    }

    /// @notice Getter function for fetching the delayedWithdrawal at the `index`th entry from the `_userWithdrawals[user].delayedWithdrawals` array
    function userDelayedWithdrawalByIndex(
        address user,
        uint256 index
    ) external view returns (DelayedWithdrawal memory) {
        return _userWithdrawals[user].delayedWithdrawals[index];
    }

    /// @notice Getter function for fetching the length of the delayedWithdrawals array of a specific user
    function userWithdrawalsLength(address user) external view returns (uint256) {
        return _userWithdrawals[user].delayedWithdrawals.length;
    }

    /// @notice Convenience function for checking whether or not the delayedWithdrawal at the `index`th entry from the `_userWithdrawals[user].delayedWithdrawals` array is currently claimable
    function canClaimDelayedWithdrawal(address user, uint256 index) external view returns (bool) {
        return ((index >= _userWithdrawals[user].delayedWithdrawalsCompleted) &&
            (block.number >= _userWithdrawals[user].delayedWithdrawals[index].blockCreated + withdrawalDelayBlocks));
    }

    /// @notice internal function used in both of the overloaded `claimDelayedWithdrawals` functions
    function _claimDelayedWithdrawals(address recipient, uint256 maxNumberOfDelayedWithdrawalsToClaim) internal {
        uint256 amountToSend = 0;
        uint256 delayedWithdrawalsCompletedBefore = _userWithdrawals[recipient].delayedWithdrawalsCompleted;
        uint256 _userWithdrawalsLength = _userWithdrawals[recipient].delayedWithdrawals.length;
        uint256 i = 0;
        while (
            i < maxNumberOfDelayedWithdrawalsToClaim && (delayedWithdrawalsCompletedBefore + i) < _userWithdrawalsLength
        ) {
            // copy delayedWithdrawal from storage to memory
            DelayedWithdrawal memory delayedWithdrawal = _userWithdrawals[recipient].delayedWithdrawals[
                delayedWithdrawalsCompletedBefore + i
            ];
            // check if delayedWithdrawal can be claimed. break the loop as soon as a delayedWithdrawal cannot be claimed
            if (block.number < delayedWithdrawal.blockCreated + withdrawalDelayBlocks) {
                break;
            }
            // otherwise, the delayedWithdrawal can be claimed, in which case we increase the amountToSend and increment i
            amountToSend += delayedWithdrawal.amount;
            // increment i to account for the delayedWithdrawal being claimed
            unchecked {
                ++i;
            }
        }
        // mark the i delayedWithdrawals as claimed
        _userWithdrawals[recipient].delayedWithdrawalsCompleted = delayedWithdrawalsCompletedBefore + i;
        // actually send the ETH
        if (amountToSend != 0) {
            AddressUpgradeable.sendValue(payable(recipient), amountToSend);
        }
        emit DelayedWithdrawalsClaimed(recipient, amountToSend, delayedWithdrawalsCompletedBefore + i);
    }

    /// @notice internal function for changing the value of `withdrawalDelayBlocks`. Also performs sanity check and emits an event.
    function _setWithdrawalDelayBlocks(uint256 newValue) internal {
        require(
            newValue <= MAX_WITHDRAWAL_DELAY_BLOCKS,
            "DelayedWithdrawalRouter._setWithdrawalDelayBlocks: newValue too large"
        );
        emit WithdrawalDelayBlocksSet(withdrawalDelayBlocks, newValue);
        withdrawalDelayBlocks = newValue;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[48] private __gap;
}