Hanzo Rollups

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@hanzo/rollups/IL2Bridge.sol";
import "@hanzo/rollups/ICrossChainMessenger.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/// @title L2Bridge - Bridge assets between L1 and L2 rollups
contract L2Bridge {
    IL2Bridge public bridge;
    ICrossChainMessenger public messenger;

    mapping(bytes32 => bool) public processedDeposits;

    event DepositInitiated(address indexed from, uint256 amount, uint256 l2ChainId);
    event WithdrawalCompleted(address indexed to, uint256 amount);

    constructor(address _bridge, address _messenger) {
        bridge = IL2Bridge(_bridge);
        messenger = ICrossChainMessenger(_messenger);
    }

    // Bridge ETH from L1 to L2
    function bridgeETHToL2(uint256 l2ChainId) external payable {
        bridge.depositETH{value: msg.value}(l2ChainId, msg.sender);
        emit DepositInitiated(msg.sender, msg.value, l2ChainId);
    }

    // Bridge ERC20 tokens to L2
    function bridgeTokenToL2(
        address token,
        uint256 amount,
        uint256 l2ChainId
    ) external {
        IERC20(token).transferFrom(msg.sender, address(this), amount);
        IERC20(token).approve(address(bridge), amount);
        bridge.depositERC20(token, amount, l2ChainId, msg.sender);
        emit DepositInitiated(msg.sender, amount, l2ChainId);
    }

    // Finalize withdrawal on L1 (called by relayer)
    function finalizeWithdrawal(
        bytes32 withdrawalHash,
        address to,
        uint256 amount,
        bytes calldata proof
    ) external {
        require(!processedDeposits[withdrawalHash], "Already processed");
        require(bridge.verifyWithdrawalProof(withdrawalHash, proof), "Invalid proof");

        processedDeposits[withdrawalHash] = true;
        payable(to).transfer(amount);
        emit WithdrawalCompleted(to, amount);
    }
}