// File: contracts/tokenbridge/ethereum/gateway/L1ERC20Gateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "./L1ArbitrumExtendedGateway.sol";
import "@openzeppelin/contracts/utils/Create2.sol";
import "../../libraries/Whitelist.sol";

/**
 * @title Layer 1 Gateway contract for bridging standard ERC20s
 * @notice This contract handles token deposits, holds the escrowed tokens on layer 1, and (ultimately) finalizes withdrawals.
 * @dev Any ERC20 that requires non-standard functionality should use a separate gateway.
 * Messages to layer 2 use the inbox's createRetryableTicket method.
 */
contract L1ERC20Gateway is L1ArbitrumExtendedGateway {
    // used for create2 address calculation
    bytes32 public cloneableProxyHash;
    // We don't use the solidity creationCode as it breaks when upgrading contracts
    // keccak256(type(ClonableBeaconProxy).creationCode);
    address public l2BeaconProxyFactory;
    // whitelist not used anymore
    address public whitelist;

    // start of inline reentrancy guard
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.2/contracts/utils/ReentrancyGuard.sol
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;

    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        _status = _NOT_ENTERED;
    }

    // end of inline reentrancy guard

    function outboundTransferCustomRefund(
        address _l1Token,
        address _refundTo,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) public payable virtual override nonReentrant returns (bytes memory res) {
        return
            super.outboundTransferCustomRefund(
                _l1Token,
                _refundTo,
                _to,
                _amount,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }

    function finalizeInboundTransfer(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _data
    ) public payable override nonReentrant {
        // the superclass checks onlyCounterpartGateway
        super.finalizeInboundTransfer(_token, _from, _to, _amount, _data);
    }

    function initialize(
        address _l2Counterpart,
        address _router,
        address _inbox,
        bytes32 _cloneableProxyHash,
        address _l2BeaconProxyFactory
    ) public {
        L1ArbitrumGateway._initialize(_l2Counterpart, _router, _inbox);
        require(_cloneableProxyHash != bytes32(0), "INVALID_PROXYHASH");
        require(_l2BeaconProxyFactory != address(0), "INVALID_BEACON");
        cloneableProxyHash = _cloneableProxyHash;
        l2BeaconProxyFactory = _l2BeaconProxyFactory;
        // disable whitelist by default
        whitelist = address(0);
        // reentrancy guard
        _status = _NOT_ENTERED;
    }

    /**
     * @notice utility function used to perform external read-only calls.
     * @dev the result is returned even if the call failed or was directed at an EOA,
     * it is cheaper to have the L2 consumer identify and deal with this.
     * @return result bytes, even if the call failed.
     */
    function callStatic(address targetContract, bytes4 targetFunction)
        internal
        view
        returns (bytes memory)
    {
        (
            ,
            /* bool success */
            bytes memory res
        ) = targetContract.staticcall(abi.encodeWithSelector(targetFunction));
        return res;
    }

    function getOutboundCalldata(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _data
    ) public view override returns (bytes memory outboundCalldata) {
        // TODO: cheaper to make static calls or save isDeployed to storage?
        bytes memory deployData = abi.encode(
            callStatic(_token, ERC20.name.selector),
            callStatic(_token, ERC20.symbol.selector),
            callStatic(_token, ERC20.decimals.selector)
        );

        outboundCalldata = abi.encodeWithSelector(
            ITokenGateway.finalizeInboundTransfer.selector,
            _token,
            _from,
            _to,
            _amount,
            GatewayMessageHandler.encodeToL2GatewayMsg(deployData, _data)
        );

        return outboundCalldata;
    }

    function calculateL2TokenAddress(address l1ERC20)
        public
        view
        override(ITokenGateway, TokenGateway)
        returns (address)
    {
        bytes32 salt = getSalt(l1ERC20);
        return Create2.computeAddress(salt, cloneableProxyHash, l2BeaconProxyFactory);
    }

    function getSalt(address l1ERC20) internal view returns (bytes32) {
        // TODO: use a library
        return keccak256(abi.encode(counterpartGateway, keccak256(abi.encode(l1ERC20))));
    }
}

// File: contracts/tokenbridge/ethereum/gateway/L1ArbitrumExtendedGateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "../../libraries/ITransferAndCall.sol";

import "./L1ArbitrumGateway.sol";

interface ITradeableExitReceiver {
    function onExitTransfer(
        address sender,
        uint256 exitNum,
        bytes calldata data
    ) external returns (bool);
}

abstract contract L1ArbitrumExtendedGateway is L1ArbitrumGateway {
    using Address for address;

    struct ExitData {
        bool isExit;
        address _newTo;
        bytes _newData;
    }

    mapping(bytes32 => ExitData) public redirectedExits;

    event WithdrawRedirected(
        address indexed from,
        address indexed to,
        uint256 indexed exitNum,
        bytes newData,
        bytes data,
        bool madeExternalCall
    );

    /**
     * @notice Allows a user to redirect their right to claim a withdrawal to another address.
     * @dev This method also allows you to make an arbitrary call after the transfer.
     * This does not validate if the exit was already triggered. It is assumed the `_exitNum` is
     * validated off-chain to ensure this was not yet triggered.
     * @param _exitNum Sequentially increasing exit counter determined by the L2 bridge
     * @param _initialDestination address the L2 withdrawal call initially set as the destination.
     * @param _newDestination address the L1 will now call instead of the previously set destination
     * @param _newData data to be used in inboundEscrowAndCall
     * @param _data optional data for external call upon transfering the exit
     */
    function transferExitAndCall(
        uint256 _exitNum,
        address _initialDestination,
        address _newDestination,
        bytes calldata _newData,
        bytes calldata _data
    ) external {
        // the initial data doesn't make a difference when transfering you exit
        // since the L2 bridge gives a unique exit ID to each exit
        (address expectedSender, ) = getExternalCall(_exitNum, _initialDestination, "");

        // if you want to transfer your exit, you must be the current destination
        require(msg.sender == expectedSender, "NOT_EXPECTED_SENDER");
        // the inboundEscrowAndCall functionality has been disabled, so no data is allowed
        require(_newData.length == 0, "NO_DATA_ALLOWED");

        setRedirectedExit(_exitNum, _initialDestination, _newDestination, _newData);

        if (_data.length > 0) {
            require(_newDestination.isContract(), "TO_NOT_CONTRACT");
            bool success = ITradeableExitReceiver(_newDestination).onExitTransfer(
                expectedSender,
                _exitNum,
                _data
            );
            require(success, "TRANSFER_HOOK_FAIL");
        }

        emit WithdrawRedirected(
            expectedSender,
            _newDestination,
            _exitNum,
            _newData,
            _data,
            _data.length > 0
        );
    }

    /// @notice this does not verify if the external call was already done
    function getExternalCall(
        uint256 _exitNum,
        address _initialDestination,
        bytes memory _initialData
    ) public view virtual override returns (address target, bytes memory data) {
        // this function is virtual so that subclasses can override it with custom logic where necessary
        bytes32 withdrawData = encodeWithdrawal(_exitNum, _initialDestination);
        ExitData storage exit = redirectedExits[withdrawData];

        // here we don't authenticate `_initialData`. we could hash it into `withdrawData` but would increase gas costs
        // this is safe because if the exit isn't overriden, the _initialData coming from L2 is trusted
        // but if the exit is traded, all we care about is the latest user calldata
        if (exit.isExit) {
            return (exit._newTo, exit._newData);
        } else {
            return (_initialDestination, _initialData);
        }
    }

    function setRedirectedExit(
        uint256 _exitNum,
        address _initialDestination,
        address _newDestination,
        bytes memory _newData
    ) internal virtual {
        bytes32 withdrawData = encodeWithdrawal(_exitNum, _initialDestination);
        redirectedExits[withdrawData] = ExitData(true, _newDestination, _newData);
    }

    function encodeWithdrawal(uint256 _exitNum, address _initialDestination)
        public
        pure
        returns (bytes32)
    {
        // here we assume the L2 bridge gives a unique exitNum to each exit
        return keccak256(abi.encode(_exitNum, _initialDestination));
    }
}

// File: node_modules/@openzeppelin/contracts/utils/Create2.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Create2.sol)

pragma solidity ^0.8.0;

/**
 * @dev Helper to make usage of the `CREATE2` EVM opcode easier and safer.
 * `CREATE2` can be used to compute in advance the address where a smart
 * contract will be deployed, which allows for interesting new mechanisms known
 * as 'counterfactual interactions'.
 *
 * See the https://eips.ethereum.org/EIPS/eip-1014#motivation[EIP] for more
 * information.
 */
library Create2 {
    /**
     * @dev Deploys a contract using `CREATE2`. The address where the contract
     * will be deployed can be known in advance via {computeAddress}.
     *
     * The bytecode for a contract can be obtained from Solidity with
     * `type(contractName).creationCode`.
     *
     * Requirements:
     *
     * - `bytecode` must not be empty.
     * - `salt` must have not been used for `bytecode` already.
     * - the factory must have a balance of at least `amount`.
     * - if `amount` is non-zero, `bytecode` must have a `payable` constructor.
     */
    function deploy(
        uint256 amount,
        bytes32 salt,
        bytes memory bytecode
    ) internal returns (address addr) {
        require(address(this).balance >= amount, "Create2: insufficient balance");
        require(bytecode.length != 0, "Create2: bytecode length is zero");
        /// @solidity memory-safe-assembly
        assembly {
            addr := create2(amount, add(bytecode, 0x20), mload(bytecode), salt)
        }
        require(addr != address(0), "Create2: Failed on deploy");
    }

    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy}. Any change in the
     * `bytecodeHash` or `salt` will result in a new destination address.
     */
    function computeAddress(bytes32 salt, bytes32 bytecodeHash) internal view returns (address) {
        return computeAddress(salt, bytecodeHash, address(this));
    }

    /**
     * @dev Returns the address where a contract will be stored if deployed via {deploy} from a contract located at
     * `deployer`. If `deployer` is this contract's address, returns the same value as {computeAddress}.
     */
    function computeAddress(
        bytes32 salt,
        bytes32 bytecodeHash,
        address deployer
    ) internal pure returns (address addr) {
        /// @solidity memory-safe-assembly
        assembly {
            let ptr := mload(0x40) // Get free memory pointer

            // |                   | ↓ ptr ...  ↓ ptr + 0x0B (start) ...  ↓ ptr + 0x20 ...  ↓ ptr + 0x40 ...   |
            // |-------------------|---------------------------------------------------------------------------|
            // | bytecodeHash      |                                                        CCCCCCCCCCCCC...CC |
            // | salt              |                                      BBBBBBBBBBBBB...BB                   |
            // | deployer          | 000000...0000AAAAAAAAAAAAAAAAAAA...AA                                     |
            // | 0xFF              |            FF                                                             |
            // |-------------------|---------------------------------------------------------------------------|
            // | memory            | 000000...00FFAAAAAAAAAAAAAAAAAAA...AABBBBBBBBBBBBB...BBCCCCCCCCCCCCC...CC |
            // | keccak(start, 85) |            ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑ |

            mstore(add(ptr, 0x40), bytecodeHash)
            mstore(add(ptr, 0x20), salt)
            mstore(ptr, deployer) // Right-aligned with 12 preceding garbage bytes
            let start := add(ptr, 0x0b) // The hashed data starts at the final garbage byte which we will set to 0xff
            mstore8(start, 0xff)
            addr := keccak256(start, 85)
        }
    }
}

// File: contracts/tokenbridge/libraries/Whitelist.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2021, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

abstract contract WhitelistConsumer {
    address public whitelist;

    event WhitelistSourceUpdated(address newSource);

    modifier onlyWhitelisted() {
        if (whitelist != address(0)) {
            require(Whitelist(whitelist).isAllowed(msg.sender), "NOT_WHITELISTED");
        }
        _;
    }

    function updateWhitelistSource(address newSource) external {
        require(msg.sender == whitelist, "NOT_FROM_LIST");
        whitelist = newSource;
        emit WhitelistSourceUpdated(newSource);
    }
}

contract Whitelist {
    address public owner;
    mapping(address => bool) public isAllowed;

    event OwnerUpdated(address newOwner);
    event WhitelistUpgraded(address newWhitelist, address[] targets);

    constructor() {
        owner = msg.sender;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "ONLY_OWNER");
        _;
    }

    function setOwner(address newOwner) external onlyOwner {
        owner = newOwner;
        emit OwnerUpdated(newOwner);
    }

    function setWhitelist(address[] memory user, bool[] memory val) external onlyOwner {
        require(user.length == val.length, "INVALID_INPUT");

        for (uint256 i = 0; i < user.length; i++) {
            isAllowed[user[i]] = val[i];
        }
    }

    // set new whitelist to address(0) to disable whitelist
    function triggerConsumers(address newWhitelist, address[] memory targets) external onlyOwner {
        for (uint256 i = 0; i < targets.length; i++) {
            WhitelistConsumer(targets[i]).updateWhitelistSource(newWhitelist);
        }
        emit WhitelistUpgraded(newWhitelist, targets);
    }
}

// File: contracts/tokenbridge/libraries/ITransferAndCall.sol



// SPDX-License-Identifier: MIT
// solhint-disable-next-line compiler-version
pragma solidity >0.6.0 <0.9.0;

import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";

interface ITransferAndCall is IERC20Upgradeable {
    function transferAndCall(
        address to,
        uint256 value,
        bytes memory data
    ) external returns (bool success);

    event Transfer(address indexed from, address indexed to, uint256 value, bytes data);
}

/**
 * @notice note that implementation of ITransferAndCallReceiver is not expected to return a success bool
 */
interface ITransferAndCallReceiver {
    function onTokenTransfer(
        address _sender,
        uint256 _value,
        bytes memory _data
    ) external;
}

// File: contracts/tokenbridge/ethereum/gateway/L1ArbitrumGateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Create2.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "../L1ArbitrumMessenger.sol";
import "./IL1ArbitrumGateway.sol";
import "../../libraries/ProxyUtil.sol";
import "../../libraries/gateway/GatewayMessageHandler.sol";
import "../../libraries/gateway/TokenGateway.sol";
import "../../libraries/ITransferAndCall.sol";
import "../../libraries/ERC165.sol";

/**
 * @title Common interface for gatways on L1 messaging to Arbitrum.
 */
abstract contract L1ArbitrumGateway is
    L1ArbitrumMessenger,
    TokenGateway,
    ERC165,
    IL1ArbitrumGateway
{
    using SafeERC20 for IERC20;
    using Address for address;

    address public override inbox;

    event DepositInitiated(
        address l1Token,
        address indexed _from,
        address indexed _to,
        uint256 indexed _sequenceNumber,
        uint256 _amount
    );

    event WithdrawalFinalized(
        address l1Token,
        address indexed _from,
        address indexed _to,
        uint256 indexed _exitNum,
        uint256 _amount
    );

    modifier onlyCounterpartGateway() override {
        address _inbox = inbox;

        // a message coming from the counterpart gateway was executed by the bridge
        address bridge = address(super.getBridge(_inbox));
        require(msg.sender == bridge, "NOT_FROM_BRIDGE");

        // and the outbox reports that the L2 address of the sender is the counterpart gateway
        address l2ToL1Sender = super.getL2ToL1Sender(_inbox);
        require(l2ToL1Sender == counterpartGateway, "ONLY_COUNTERPART_GATEWAY");
        _;
    }

    function postUpgradeInit() external {
        // it is assumed the L1 Arbitrum Gateway contract is behind a Proxy controlled by a proxy admin
        // this function can only be called by the proxy admin contract
        address proxyAdmin = ProxyUtil.getProxyAdmin();
        require(msg.sender == proxyAdmin, "NOT_FROM_ADMIN");
        // this has no other logic since the current upgrade doesn't require this logic
    }

    function _initialize(
        address _l2Counterpart,
        address _router,
        address _inbox
    ) internal {
        TokenGateway._initialize(_l2Counterpart, _router);
        // L1 gateway must have a router
        require(_router != address(0), "BAD_ROUTER");
        require(_inbox != address(0), "BAD_INBOX");
        inbox = _inbox;
    }

    /**
     * @notice Finalizes a withdrawal via Outbox message; callable only by L2Gateway.outboundTransfer
     * @param _token L1 address of token being withdrawn from
     * @param _from initiator of withdrawal
     * @param _to address the L2 withdrawal call set as the destination.
     * @param _amount Token amount being withdrawn
     * @param _data encoded exitNum (Sequentially increasing exit counter determined by the L2Gateway) and additinal hook data
     */
    function finalizeInboundTransfer(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _data
    ) public payable virtual override onlyCounterpartGateway {
        // this function is marked as virtual so superclasses can override it to add modifiers
        (uint256 exitNum, bytes memory callHookData) = GatewayMessageHandler.parseToL1GatewayMsg(
            _data
        );

        if (callHookData.length != 0) {
            // callHookData should always be 0 since inboundEscrowAndCall is disabled
            callHookData = bytes("");
        }

        // we ignore the returned data since the callHook feature is now disabled
        (_to, ) = getExternalCall(exitNum, _to, callHookData);
        inboundEscrowTransfer(_token, _to, _amount);

        emit WithdrawalFinalized(_token, _from, _to, exitNum, _amount);
    }

    function getExternalCall(
        uint256, /* _exitNum */
        address _initialDestination,
        bytes memory _initialData
    ) public view virtual returns (address target, bytes memory data) {
        // this method is virtual so the destination of a call can be changed
        // using tradeable exits in a subclass (L1ArbitrumExtendedGateway)
        target = _initialDestination;
        data = _initialData;
    }

    function inboundEscrowTransfer(
        address _l1Token,
        address _dest,
        uint256 _amount
    ) internal virtual {
        // this method is virtual since different subclasses can handle escrow differently
        IERC20(_l1Token).safeTransfer(_dest, _amount);
    }

    /**
     * @dev Only excess gas is refunded to the _refundTo account, l2 call value is always returned to the _to account
     */
    function createOutboundTxCustomRefund(
        address _refundTo,
        address _from,
        uint256, /* _tokenAmount */
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        bytes memory _outboundCalldata
    ) internal virtual returns (uint256) {
        // We make this function virtual since outboundTransfer logic is the same for many gateways
        // but sometimes (ie weth) you construct the outgoing message differently.

        // msg.value is sent, but 0 is set to the L2 call value
        // the eth sent is used to pay for the tx's gas
        return
            sendTxToL2CustomRefund(
                inbox,
                counterpartGateway,
                _refundTo,
                _from,
                msg.value, // we forward the L1 call value to the inbox
                0, // l2 call value 0 by default
                L2GasParams({
                    _maxSubmissionCost: _maxSubmissionCost,
                    _maxGas: _maxGas,
                    _gasPriceBid: _gasPriceBid
                }),
                _outboundCalldata
            );
    }

    /**
     * @notice DEPRECATED - look at createOutboundTxCustomRefund instead
     */
    function createOutboundTx(
        address _from,
        uint256 _tokenAmount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        bytes memory _outboundCalldata
    ) internal returns (uint256) {
        return
            createOutboundTxCustomRefund(
                _from,
                _from,
                _tokenAmount,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                _outboundCalldata
            );
    }

    /**
     * @notice DEPRECATED - look at outboundTransferCustomRefund instead
     */
    function outboundTransfer(
        address _l1Token,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) public payable override returns (bytes memory res) {
        return
            outboundTransferCustomRefund(_l1Token, _to, _to, _amount, _maxGas, _gasPriceBid, _data);
    }

    /**
     * @notice Deposit ERC20 token from Ethereum into Arbitrum. If L2 side hasn't been deployed yet, includes name/symbol/decimals data for initial L2 deploy. Initiate by GatewayRouter.
     * @dev L2 address alias will not be applied to the following types of addresses on L1:
     *      - an externally-owned account
     *      - a contract in construction
     *      - an address where a contract will be created
     *      - an address where a contract lived, but was destroyed
     * @param _l1Token L1 address of ERC20
     * @param _refundTo Account, or its L2 alias if it have code in L1, to be credited with excess gas refund in L2
     * @param _to Account to be credited with the tokens in the L2 (can be the user's L2 account or a contract), not subject to L2 aliasing
                  This account, or its L2 alias if it have code in L1, will also be able to cancel the retryable ticket and receive callvalue refund
     * @param _amount Token Amount
     * @param _maxGas Max gas deducted from user's L2 balance to cover L2 execution
     * @param _gasPriceBid Gas price for L2 execution
     * @param _data encoded data from router and user
     * @return res abi encoded inbox sequence number
     */
    //  * @param maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
    function outboundTransferCustomRefund(
        address _l1Token,
        address _refundTo,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) public payable virtual override returns (bytes memory res) {
        require(isRouter(msg.sender), "NOT_FROM_ROUTER");
        // This function is set as public and virtual so that subclasses can override
        // it and add custom validation for callers (ie only whitelisted users)
        address _from;
        uint256 seqNum;
        bytes memory extraData;
        {
            uint256 _maxSubmissionCost;
            uint256 tokenTotalFeeAmount;
            if (super.isRouter(msg.sender)) {
                // router encoded
                (_from, extraData) = GatewayMessageHandler.parseFromRouterToGateway(_data);
            } else {
                _from = msg.sender;
                extraData = _data;
            }
            // unpack user encoded data
            (_maxSubmissionCost, extraData, tokenTotalFeeAmount) = _parseUserEncodedData(extraData);

            // the inboundEscrowAndCall functionality has been disabled, so no data is allowed
            require(extraData.length == 0, "EXTRA_DATA_DISABLED");

            require(_l1Token.isContract(), "L1_NOT_CONTRACT");
            address l2Token = calculateL2TokenAddress(_l1Token);
            require(l2Token != address(0), "NO_L2_TOKEN_SET");

            _amount = outboundEscrowTransfer(_l1Token, _from, _amount);

            // we override the res field to save on the stack
            res = getOutboundCalldata(_l1Token, _from, _to, _amount, extraData);

            seqNum = _initiateDeposit(
                _refundTo,
                _from,
                _amount,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                tokenTotalFeeAmount,
                res
            );
        }
        emit DepositInitiated(_l1Token, _from, _to, seqNum, _amount);
        return abi.encode(seqNum);
    }

    function outboundEscrowTransfer(
        address _l1Token,
        address _from,
        uint256 _amount
    ) internal virtual returns (uint256 amountReceived) {
        // this method is virtual since different subclasses can handle escrow differently
        // user funds are escrowed on the gateway using this function
        uint256 prevBalance = IERC20(_l1Token).balanceOf(address(this));
        IERC20(_l1Token).safeTransferFrom(_from, address(this), _amount);
        uint256 postBalance = IERC20(_l1Token).balanceOf(address(this));
        return postBalance - prevBalance;
    }

    function getOutboundCalldata(
        address _l1Token,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _data
    ) public view virtual override returns (bytes memory outboundCalldata) {
        // this function is public so users can query how much calldata will be sent to the L2
        // before execution
        // it is virtual since different gateway subclasses can build this calldata differently
        // ( ie the standard ERC20 gateway queries for a tokens name/symbol/decimals )
        bytes memory emptyBytes = "";

        outboundCalldata = abi.encodeWithSelector(
            ITokenGateway.finalizeInboundTransfer.selector,
            _l1Token,
            _from,
            _to,
            _amount,
            GatewayMessageHandler.encodeToL2GatewayMsg(emptyBytes, _data)
        );

        return outboundCalldata;
    }

    function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(ERC165, IERC165)
        returns (bool)
    {
        // registering interfaces that is added after arb-bridge-peripherals >1.0.11
        // using function selector instead of single function interfaces to reduce bloat
        return
            interfaceId == this.outboundTransferCustomRefund.selector ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @notice Parse data that was encoded by user and passed into the outbound TX entrypoint
     * @dev In case of standard ETH-based rollup, format of encoded data is expected to be:
     *      - maxSubmissionCost (uint256)
     *      - callHookData (bytes)
     *      In case of ERC20-based rollup, format of encoded data is expected to be:
     *      - maxSubmissionCost (uint256)
     *      - tokenTotalFeeAmount (uint256)
     *      - callHookData (bytes)
     * @param data data encoded by user
     * @return maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @return callHookData Calldata for extra call in inboundEscrowAndCall on L2
     * @return tokenTotalFeeAmount Amount of fees to be deposited in native token to cover for retryable ticket cost (used only in ERC20-based rollups, otherwise 0)
     */
    function _parseUserEncodedData(bytes memory data)
        internal
        pure
        virtual
        returns (
            uint256 maxSubmissionCost,
            bytes memory callHookData,
            uint256 tokenTotalFeeAmount
        )
    {
        (maxSubmissionCost, callHookData) = abi.decode(data, (uint256, bytes));
    }

    /**
     * @notice Intermediate internal function that passes on parameters needed to trigger creation of retryable ticket.
     * @param _refundTo Account, or its L2 alias if it have code in L1, to be credited with excess gas refund in L2
     * @param _from Initiator of deposit
     * @param _amount Token amount being deposited
     * @param _maxGas Max gas deducted from user's L2 balance to cover L2 execution
     * @param _gasPriceBid Gas price for L2 execution
     * @param _maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @param _data encoded data from router and user
     * @return res abi encoded inbox sequence number
     */
    function _initiateDeposit(
        address _refundTo,
        address _from,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        uint256, // tokenTotalFeeAmount - amount of fees to be deposited in native token to cover for retryable ticket cost (used only in ERC20-based rollups)
        bytes memory _data
    ) internal virtual returns (uint256) {
        return
            createOutboundTxCustomRefund(
                _refundTo,
                _from,
                _amount,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                _data
            );
    }
}

// File: node_modules/@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20Upgradeable {
    /**
     * @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 amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves `amount` 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 amount) 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 `amount` 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 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` 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 amount
    ) external returns (bool);
}

// File: node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: node_modules/@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: node_modules/@openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

// File: contracts/tokenbridge/ethereum/L1ArbitrumMessenger.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "@arbitrum/nitro-contracts/src/bridge/IInbox.sol";
import "@arbitrum/nitro-contracts/src/bridge/IOutbox.sol";

/// @notice L1 utility contract to assist with L1 <=> L2 interactions
/// @dev this is an abstract contract instead of library so the functions can be easily overriden when testing
abstract contract L1ArbitrumMessenger {
    event TxToL2(address indexed _from, address indexed _to, uint256 indexed _seqNum, bytes _data);

    struct L2GasParams {
        uint256 _maxSubmissionCost;
        uint256 _maxGas;
        uint256 _gasPriceBid;
    }

    function sendTxToL2CustomRefund(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        L2GasParams memory _l2GasParams,
        bytes memory _data
    ) internal returns (uint256) {
        // alternative function entry point when struggling with the stack size
        return
            sendTxToL2CustomRefund(
                _inbox,
                _to,
                _refundTo,
                _user,
                _l1CallValue,
                _l2CallValue,
                _l2GasParams._maxSubmissionCost,
                _l2GasParams._maxGas,
                _l2GasParams._gasPriceBid,
                _data
            );
    }

    function sendTxToL2(
        address _inbox,
        address _to,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        L2GasParams memory _l2GasParams,
        bytes memory _data
    ) internal returns (uint256) {
        // alternative function entry point when struggling with the stack size
        return
            sendTxToL2(
                _inbox,
                _to,
                _user,
                _l1CallValue,
                _l2CallValue,
                _l2GasParams._maxSubmissionCost,
                _l2GasParams._maxGas,
                _l2GasParams._gasPriceBid,
                _data
            );
    }

    function sendTxToL2CustomRefund(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal returns (uint256) {
        uint256 seqNum = _createRetryable(
            _inbox,
            _to,
            _refundTo,
            _user,
            _l1CallValue,
            _l2CallValue,
            _maxSubmissionCost,
            _maxGas,
            _gasPriceBid,
            _data
        );
        emit TxToL2(_user, _to, seqNum, _data);
        return seqNum;
    }

    function sendTxToL2(
        address _inbox,
        address _to,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal returns (uint256) {
        return
            sendTxToL2CustomRefund(
                _inbox,
                _to,
                _user,
                _user,
                _l1CallValue,
                _l2CallValue,
                _maxSubmissionCost,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }

    function getBridge(address _inbox) internal view returns (IBridge) {
        return IInbox(_inbox).bridge();
    }

    /// @dev the l2ToL1Sender behaves as the tx.origin, the msg.sender should be validated to protect against reentrancies
    function getL2ToL1Sender(address _inbox) internal view returns (address) {
        IOutbox outbox = IOutbox(getBridge(_inbox).activeOutbox());
        address l2ToL1Sender = outbox.l2ToL1Sender();

        require(l2ToL1Sender != address(0), "NO_SENDER");
        return l2ToL1Sender;
    }

    /**
     * @notice Calls inbox to create retryable ticket. Default implementation is for standard Eth-based rollup, but it can be overriden to create retryable in ERC20-based rollup.
     * @param _inbox address of the rollup's inbox
     * @param _to destination L2 contract address
     * @param _refundTo refund address for excess fee
     * @param _user refund address for callvalue
     * @param _totalFeeAmount amount of fees to pay, in Eth or native token, for retryable's execution
     * @param _l2CallValue call value for retryable L2 message
     * @param _maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @param _maxGas Max gas deducted from user's L2 balance to cover L2 execution
     * @param _gasPriceBid price bid for L2 execution
     * @param _data ABI encoded data of L2 message
     * @return unique message number of the retryable transaction
     */
    function _createRetryable(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _totalFeeAmount,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal virtual returns (uint256) {
        return
            IInbox(_inbox).createRetryableTicket{ value: _totalFeeAmount }(
                _to,
                _l2CallValue,
                _maxSubmissionCost,
                _refundTo,
                _user,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }
}

interface IERC20Inbox {
    function createRetryableTicket(
        address to,
        uint256 l2CallValue,
        uint256 maxSubmissionCost,
        address excessFeeRefundAddress,
        address callValueRefundAddress,
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 tokenTotalFeeAmount,
        bytes calldata data
    ) external returns (uint256);
}
// File: contracts/tokenbridge/ethereum/gateway/IL1ArbitrumGateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

import "../../libraries/gateway/ITokenGateway.sol";
import "../../libraries/IERC165.sol";

/**
 * @title Common interface for gatways on L1 messaging to Arbitrum.
 */
interface IL1ArbitrumGateway is ITokenGateway, IERC165 {
    function inbox() external view returns (address);

    /**
     * @notice Deposit ERC20 token from Ethereum into Arbitrum. If L2 side hasn't been deployed yet, includes name/symbol/decimals data for initial L2 deploy. Initiate by GatewayRouter.
     * @dev L2 address alias will not be applied to the following types of addresses on L1:
     *      - an externally-owned account
     *      - a contract in construction
     *      - an address where a contract will be created
     *      - an address where a contract lived, but was destroyed
     * @param _l1Token L1 address of ERC20
     * @param _refundTo Account, or its L2 alias if it have code in L1, to be credited with excess gas refund in L2
     * @param _to Account to be credited with the tokens in the L2 (can be the user's L2 account or a contract), not subject to L2 aliasing
                  This account, or its L2 alias if it have code in L1, will also be able to cancel the retryable ticket and receive callvalue refund
     * @param _amount Token Amount
     * @param _maxGas Max gas deducted from user's L2 balance to cover L2 execution
     * @param _gasPriceBid Gas price for L2 execution
     * @param _data encoded data from router and user
     * @return res abi encoded inbox sequence number
     */
    //  * @param maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
    function outboundTransferCustomRefund(
        address _l1Token,
        address _refundTo,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) external payable returns (bytes memory);
}

// File: contracts/tokenbridge/libraries/ProxyUtil.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2021, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

library ProxyUtil {
    function getProxyAdmin() internal view returns (address admin) {
        // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/proxy/TransparentUpgradeableProxy.sol#L48
        // Storage slot with the admin of the proxy contract.
        // This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
        bytes32 slot = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
        assembly {
            admin := sload(slot)
        }
    }
}

// File: contracts/tokenbridge/libraries/gateway/GatewayMessageHandler.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2021, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

/// @notice this library manages encoding and decoding of gateway communication
library GatewayMessageHandler {
    // these are for communication from L1 to L2 gateway

    function encodeToL2GatewayMsg(bytes memory gatewayData, bytes memory callHookData)
        internal
        pure
        returns (bytes memory res)
    {
        res = abi.encode(gatewayData, callHookData);
    }

    function parseFromL1GatewayMsg(bytes calldata _data)
        internal
        pure
        returns (bytes memory gatewayData, bytes memory callHookData)
    {
        // abi decode may revert, but the encoding is done by L1 gateway, so we trust it
        (gatewayData, callHookData) = abi.decode(_data, (bytes, bytes));
    }

    // these are for communication from L2 to L1 gateway

    function encodeFromL2GatewayMsg(uint256 exitNum, bytes memory callHookData)
        internal
        pure
        returns (bytes memory res)
    {
        res = abi.encode(exitNum, callHookData);
    }

    function parseToL1GatewayMsg(bytes calldata _data)
        internal
        pure
        returns (uint256 exitNum, bytes memory callHookData)
    {
        // abi decode may revert, but the encoding is done by L1 gateway, so we trust it
        (exitNum, callHookData) = abi.decode(_data, (uint256, bytes));
    }

    // these are for communication from router to gateway

    function encodeFromRouterToGateway(address _from, bytes calldata _data)
        internal
        pure
        returns (bytes memory res)
    {
        // abi decode may revert, but the encoding is done by L1 gateway, so we trust it
        return abi.encode(_from, _data);
    }

    function parseFromRouterToGateway(bytes calldata _data)
        internal
        pure
        returns (address, bytes memory res)
    {
        // abi decode may revert, but the encoding is done by L1 gateway, so we trust it
        return abi.decode(_data, (address, bytes));
    }
}

// File: contracts/tokenbridge/libraries/gateway/TokenGateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "./ITokenGateway.sol";
import "@openzeppelin/contracts/utils/Address.sol";

abstract contract TokenGateway is ITokenGateway {
    using Address for address;

    address public counterpartGateway;
    address public router;

    // This modifier is overriden in gateways to validate the message sender
    // For L1 to L2 messages need to be validated against the aliased counterpartGateway
    // For L2 to L1 messages need to be validated against the bridge and L2ToL1Sender
    // prettier-ignore
    modifier onlyCounterpartGateway() virtual;

    function _initialize(address _counterpartGateway, address _router) internal virtual {
        // This initializes internal variables of the abstract contract it can be chained together with other functions.
        // It is virtual so subclasses can override or wrap around this logic.
        // An example where this is useful is different subclasses that validate the router address differently
        require(_counterpartGateway != address(0), "INVALID_COUNTERPART");
        require(counterpartGateway == address(0), "ALREADY_INIT");
        counterpartGateway = _counterpartGateway;
        router = _router;
    }

    function isRouter(address _target) internal view returns (bool isTargetRouter) {
        return _target == router;
    }

    /**
     * @notice Calculate the address used when bridging an ERC20 token
     * @dev the L1 and L2 address oracles may not always be in sync.
     * For example, a custom token may have been registered but not deploy or the contract self destructed.
     * @param l1ERC20 address of L1 token
     * @return L2 address of a bridged ERC20 token
     */
    function calculateL2TokenAddress(address l1ERC20)
        public
        view
        virtual
        override
        returns (address);
}

// File: contracts/tokenbridge/libraries/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

// With pragma modification to support ^0.6.11
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v4.6/contracts/utils/introspection/ERC165.sol

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: node_modules/@openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @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 amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

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

    /**
     * @dev Moves `amount` 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 amount) 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 `amount` 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 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` 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 amount
    ) external returns (bool);
}

// File: node_modules/@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: node_modules/@openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: node_modules/@openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/IInbox.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

import "./IBridge.sol";
import "./IDelayedMessageProvider.sol";
import "./ISequencerInbox.sol";

interface IInbox is IDelayedMessageProvider {
    function bridge() external view returns (IBridge);

    function sequencerInbox() external view returns (ISequencerInbox);

    /**
     * @notice Send a generic L2 message to the chain
     * @dev This method is an optimization to avoid having to emit the entirety of the messageData in a log. Instead validators are expected to be able to parse the data from the transaction's input
     *      This method will be disabled upon L1 fork to prevent replay attacks on L2
     * @param messageData Data of the message being sent
     */
    function sendL2MessageFromOrigin(bytes calldata messageData) external returns (uint256);

    /**
     * @notice Send a generic L2 message to the chain
     * @dev This method can be used to send any type of message that doesn't require L1 validation
     *      This method will be disabled upon L1 fork to prevent replay attacks on L2
     * @param messageData Data of the message being sent
     */
    function sendL2Message(bytes calldata messageData) external returns (uint256);

    function sendL1FundedUnsignedTransaction(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 nonce,
        address to,
        bytes calldata data
    ) external payable returns (uint256);

    function sendL1FundedContractTransaction(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        address to,
        bytes calldata data
    ) external payable returns (uint256);

    function sendUnsignedTransaction(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 nonce,
        address to,
        uint256 value,
        bytes calldata data
    ) external returns (uint256);

    function sendContractTransaction(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        address to,
        uint256 value,
        bytes calldata data
    ) external returns (uint256);

    /**
     * @dev This method can only be called upon L1 fork and will not alias the caller
     *      This method will revert if not called from origin
     */
    function sendL1FundedUnsignedTransactionToFork(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 nonce,
        address to,
        bytes calldata data
    ) external payable returns (uint256);

    /**
     * @dev This method can only be called upon L1 fork and will not alias the caller
     *      This method will revert if not called from origin
     */
    function sendUnsignedTransactionToFork(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 nonce,
        address to,
        uint256 value,
        bytes calldata data
    ) external returns (uint256);

    /**
     * @notice Send a message to initiate L2 withdrawal
     * @dev This method can only be called upon L1 fork and will not alias the caller
     *      This method will revert if not called from origin
     */
    function sendWithdrawEthToFork(
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 nonce,
        uint256 value,
        address withdrawTo
    ) external returns (uint256);

    /**
     * @notice Get the L1 fee for submitting a retryable
     * @dev This fee can be paid by funds already in the L2 aliased address or by the current message value
     * @dev This formula may change in the future, to future proof your code query this method instead of inlining!!
     * @param dataLength The length of the retryable's calldata, in bytes
     * @param baseFee The block basefee when the retryable is included in the chain, if 0 current block.basefee will be used
     */
    function calculateRetryableSubmissionFee(uint256 dataLength, uint256 baseFee)
        external
        view
        returns (uint256);

    /**
     * @notice Deposit eth from L1 to L2 to address of the sender if sender is an EOA, and to its aliased address if the sender is a contract
     * @dev This does not trigger the fallback function when receiving in the L2 side.
     *      Look into retryable tickets if you are interested in this functionality.
     * @dev This function should not be called inside contract constructors
     */
    function depositEth() external payable returns (uint256);

    /**
     * @notice Put a message in the L2 inbox that can be reexecuted for some fixed amount of time if it reverts
     * @dev all msg.value will deposited to callValueRefundAddress on L2
     * @dev Gas limit and maxFeePerGas should not be set to 1 as that is used to trigger the RetryableData error
     * @param to destination L2 contract address
     * @param l2CallValue call value for retryable L2 message
     * @param maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @param excessFeeRefundAddress gasLimit x maxFeePerGas - execution cost gets credited here on L2 balance
     * @param callValueRefundAddress l2Callvalue gets credited here on L2 if retryable txn times out or gets cancelled
     * @param gasLimit Max gas deducted from user's L2 balance to cover L2 execution. Should not be set to 1 (magic value used to trigger the RetryableData error)
     * @param maxFeePerGas price bid for L2 execution. Should not be set to 1 (magic value used to trigger the RetryableData error)
     * @param data ABI encoded data of L2 message
     * @return unique message number of the retryable transaction
     */
    function createRetryableTicket(
        address to,
        uint256 l2CallValue,
        uint256 maxSubmissionCost,
        address excessFeeRefundAddress,
        address callValueRefundAddress,
        uint256 gasLimit,
        uint256 maxFeePerGas,
        bytes calldata data
    ) external payable returns (uint256);

    /**
     * @notice Put a message in the L2 inbox that can be reexecuted for some fixed amount of time if it reverts
     * @dev Same as createRetryableTicket, but does not guarantee that submission will succeed by requiring the needed funds
     * come from the deposit alone, rather than falling back on the user's L2 balance
     * @dev Advanced usage only (does not rewrite aliases for excessFeeRefundAddress and callValueRefundAddress).
     * createRetryableTicket method is the recommended standard.
     * @dev Gas limit and maxFeePerGas should not be set to 1 as that is used to trigger the RetryableData error
     * @param to destination L2 contract address
     * @param l2CallValue call value for retryable L2 message
     * @param maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @param excessFeeRefundAddress gasLimit x maxFeePerGas - execution cost gets credited here on L2 balance
     * @param callValueRefundAddress l2Callvalue gets credited here on L2 if retryable txn times out or gets cancelled
     * @param gasLimit Max gas deducted from user's L2 balance to cover L2 execution. Should not be set to 1 (magic value used to trigger the RetryableData error)
     * @param maxFeePerGas price bid for L2 execution. Should not be set to 1 (magic value used to trigger the RetryableData error)
     * @param data ABI encoded data of L2 message
     * @return unique message number of the retryable transaction
     */
    function unsafeCreateRetryableTicket(
        address to,
        uint256 l2CallValue,
        uint256 maxSubmissionCost,
        address excessFeeRefundAddress,
        address callValueRefundAddress,
        uint256 gasLimit,
        uint256 maxFeePerGas,
        bytes calldata data
    ) external payable returns (uint256);

    // ---------- onlyRollupOrOwner functions ----------

    /// @notice pauses all inbox functionality
    function pause() external;

    /// @notice unpauses all inbox functionality
    function unpause() external;

    // ---------- initializer ----------

    /**
     * @dev function to be called one time during the inbox upgrade process
     *      this is used to fix the storage slots
     */
    function postUpgradeInit(IBridge _bridge) external;

    function initialize(IBridge _bridge, ISequencerInbox _sequencerInbox) external;
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/IOutbox.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

import "./IBridge.sol";

interface IOutbox {
    event SendRootUpdated(bytes32 indexed outputRoot, bytes32 indexed l2BlockHash);
    event OutBoxTransactionExecuted(
        address indexed to,
        address indexed l2Sender,
        uint256 indexed zero,
        uint256 transactionIndex
    );

    function rollup() external view returns (address); // the rollup contract

    function bridge() external view returns (IBridge); // the bridge contract

    function spent(uint256) external view returns (bytes32); // packed spent bitmap

    function roots(bytes32) external view returns (bytes32); // maps root hashes => L2 block hash

    // solhint-disable-next-line func-name-mixedcase
    function OUTBOX_VERSION() external view returns (uint128); // the outbox version

    function updateSendRoot(bytes32 sendRoot, bytes32 l2BlockHash) external;

    /// @notice When l2ToL1Sender returns a nonzero address, the message was originated by an L2 account
    ///         When the return value is zero, that means this is a system message
    /// @dev the l2ToL1Sender behaves as the tx.origin, the msg.sender should be validated to protect against reentrancies
    function l2ToL1Sender() external view returns (address);

    /// @return l2Block return L2 block when the L2 tx was initiated or 0 if no L2 to L1 transaction is active
    function l2ToL1Block() external view returns (uint256);

    /// @return l1Block return L1 block when the L2 tx was initiated or 0 if no L2 to L1 transaction is active
    function l2ToL1EthBlock() external view returns (uint256);

    /// @return timestamp return L2 timestamp when the L2 tx was initiated or 0 if no L2 to L1 transaction is active
    function l2ToL1Timestamp() external view returns (uint256);

    /// @return outputId returns the unique output identifier of the L2 to L1 tx or 0 if no L2 to L1 transaction is active
    function l2ToL1OutputId() external view returns (bytes32);

    /**
     * @notice Executes a messages in an Outbox entry.
     * @dev Reverts if dispute period hasn't expired, since the outbox entry
     *      is only created once the rollup confirms the respective assertion.
     * @dev it is not possible to execute any L2-to-L1 transaction which contains data
     *      to a contract address without any code (as enforced by the Bridge contract).
     * @param proof Merkle proof of message inclusion in send root
     * @param index Merkle path to message
     * @param l2Sender sender if original message (i.e., caller of ArbSys.sendTxToL1)
     * @param to destination address for L1 contract call
     * @param l2Block l2 block number at which sendTxToL1 call was made
     * @param l1Block l1 block number at which sendTxToL1 call was made
     * @param l2Timestamp l2 Timestamp at which sendTxToL1 call was made
     * @param value wei in L1 message
     * @param data abi-encoded L1 message data
     */
    function executeTransaction(
        bytes32[] calldata proof,
        uint256 index,
        address l2Sender,
        address to,
        uint256 l2Block,
        uint256 l1Block,
        uint256 l2Timestamp,
        uint256 value,
        bytes calldata data
    ) external;

    /**
     *  @dev function used to simulate the result of a particular function call from the outbox
     *       it is useful for things such as gas estimates. This function includes all costs except for
     *       proof validation (which can be considered offchain as a somewhat of a fixed cost - it's
     *       not really a fixed cost, but can be treated as so with a fixed overhead for gas estimation).
     *       We can't include the cost of proof validation since this is intended to be used to simulate txs
     *       that are included in yet-to-be confirmed merkle roots. The simulation entrypoint could instead pretend
     *       to confirm a pending merkle root, but that would be less practical for integrating with tooling.
     *       It is only possible to trigger it when the msg sender is address zero, which should be impossible
     *       unless under simulation in an eth_call or eth_estimateGas
     */
    function executeTransactionSimulation(
        uint256 index,
        address l2Sender,
        address to,
        uint256 l2Block,
        uint256 l1Block,
        uint256 l2Timestamp,
        uint256 value,
        bytes calldata data
    ) external;

    /**
     * @param index Merkle path to message
     * @return true if the message has been spent
     */
    function isSpent(uint256 index) external view returns (bool);

    function calculateItemHash(
        address l2Sender,
        address to,
        uint256 l2Block,
        uint256 l1Block,
        uint256 l2Timestamp,
        uint256 value,
        bytes calldata data
    ) external pure returns (bytes32);

    function calculateMerkleRoot(
        bytes32[] memory proof,
        uint256 path,
        bytes32 item
    ) external pure returns (bytes32);
}

// File: contracts/tokenbridge/libraries/gateway/ITokenGateway.sol



// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

interface ITokenGateway {
    /// @notice event deprecated in favor of DepositInitiated and WithdrawalInitiated
    // event OutboundTransferInitiated(
    //     address token,
    //     address indexed _from,
    //     address indexed _to,
    //     uint256 indexed _transferId,
    //     uint256 _amount,
    //     bytes _data
    // );

    /// @notice event deprecated in favor of DepositFinalized and WithdrawalFinalized
    // event InboundTransferFinalized(
    //     address token,
    //     address indexed _from,
    //     address indexed _to,
    //     uint256 indexed _transferId,
    //     uint256 _amount,
    //     bytes _data
    // );

    function outboundTransfer(
        address _token,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) external payable returns (bytes memory);

    function finalizeInboundTransfer(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _data
    ) external payable;

    /**
     * @notice Calculate the address used when bridging an ERC20 token
     * @dev the L1 and L2 address oracles may not always be in sync.
     * For example, a custom token may have been registered but not deploy or the contract self destructed.
     * @param l1ERC20 address of L1 token
     * @return L2 address of a bridged ERC20 token
     */
    function calculateL2TokenAddress(address l1ERC20) external view returns (address);

    function getOutboundCalldata(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes memory _data
    ) external view returns (bytes memory);
}

// File: contracts/tokenbridge/libraries/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

// With pragma modification to allow interface compatibility with >=0.6.9 <0.9.0
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/release-v4.6/contracts/utils/introspection/IERC165.sol

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/IBridge.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

import "./IOwnable.sol";

interface IBridge {
    event MessageDelivered(
        uint256 indexed messageIndex,
        bytes32 indexed beforeInboxAcc,
        address inbox,
        uint8 kind,
        address sender,
        bytes32 messageDataHash,
        uint256 baseFeeL1,
        uint64 timestamp
    );

    event BridgeCallTriggered(
        address indexed outbox,
        address indexed to,
        uint256 value,
        bytes data
    );

    event InboxToggle(address indexed inbox, bool enabled);

    event OutboxToggle(address indexed outbox, bool enabled);

    event SequencerInboxUpdated(address newSequencerInbox);

    function allowedDelayedInboxList(uint256) external returns (address);

    function allowedOutboxList(uint256) external returns (address);

    /// @dev Accumulator for delayed inbox messages; tail represents hash of the current state; each element represents the inclusion of a new message.
    function delayedInboxAccs(uint256) external view returns (bytes32);

    /// @dev Accumulator for sequencer inbox messages; tail represents hash of the current state; each element represents the inclusion of a new message.
    function sequencerInboxAccs(uint256) external view returns (bytes32);

    function rollup() external view returns (IOwnable);

    function sequencerInbox() external view returns (address);

    function activeOutbox() external view returns (address);

    function allowedDelayedInboxes(address inbox) external view returns (bool);

    function allowedOutboxes(address outbox) external view returns (bool);

    function sequencerReportedSubMessageCount() external view returns (uint256);

    /**
     * @dev Enqueue a message in the delayed inbox accumulator.
     *      These messages are later sequenced in the SequencerInbox, either
     *      by the sequencer as part of a normal batch, or by force inclusion.
     */
    function enqueueDelayedMessage(
        uint8 kind,
        address sender,
        bytes32 messageDataHash
    ) external payable returns (uint256);

    function executeCall(
        address to,
        uint256 value,
        bytes calldata data
    ) external returns (bool success, bytes memory returnData);

    function delayedMessageCount() external view returns (uint256);

    function sequencerMessageCount() external view returns (uint256);

    // ---------- onlySequencerInbox functions ----------

    function enqueueSequencerMessage(
        bytes32 dataHash,
        uint256 afterDelayedMessagesRead,
        uint256 prevMessageCount,
        uint256 newMessageCount
    )
        external
        returns (
            uint256 seqMessageIndex,
            bytes32 beforeAcc,
            bytes32 delayedAcc,
            bytes32 acc
        );

    /**
     * @dev Allows the sequencer inbox to submit a delayed message of the batchPostingReport type
     *      This is done through a separate function entrypoint instead of allowing the sequencer inbox
     *      to call `enqueueDelayedMessage` to avoid the gas overhead of an extra SLOAD in either
     *      every delayed inbox or every sequencer inbox call.
     */
    function submitBatchSpendingReport(address batchPoster, bytes32 dataHash)
        external
        returns (uint256 msgNum);

    // ---------- onlyRollupOrOwner functions ----------

    function setSequencerInbox(address _sequencerInbox) external;

    function setDelayedInbox(address inbox, bool enabled) external;

    function setOutbox(address inbox, bool enabled) external;

    // ---------- initializer ----------

    function initialize(IOwnable rollup_) external;
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/IDelayedMessageProvider.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

interface IDelayedMessageProvider {
    /// @dev event emitted when a inbox message is added to the Bridge's delayed accumulator
    event InboxMessageDelivered(uint256 indexed messageNum, bytes data);

    /// @dev event emitted when a inbox message is added to the Bridge's delayed accumulator
    /// same as InboxMessageDelivered but the batch data is available in tx.input
    event InboxMessageDeliveredFromOrigin(uint256 indexed messageNum);
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/ISequencerInbox.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;
pragma experimental ABIEncoderV2;

import "../libraries/IGasRefunder.sol";
import "./IDelayedMessageProvider.sol";
import "./IBridge.sol";

interface ISequencerInbox is IDelayedMessageProvider {
    struct MaxTimeVariation {
        uint256 delayBlocks;
        uint256 futureBlocks;
        uint256 delaySeconds;
        uint256 futureSeconds;
    }

    struct TimeBounds {
        uint64 minTimestamp;
        uint64 maxTimestamp;
        uint64 minBlockNumber;
        uint64 maxBlockNumber;
    }

    enum BatchDataLocation {
        TxInput,
        SeparateBatchEvent,
        NoData
    }

    event SequencerBatchDelivered(
        uint256 indexed batchSequenceNumber,
        bytes32 indexed beforeAcc,
        bytes32 indexed afterAcc,
        bytes32 delayedAcc,
        uint256 afterDelayedMessagesRead,
        TimeBounds timeBounds,
        BatchDataLocation dataLocation
    );

    event OwnerFunctionCalled(uint256 indexed id);

    /// @dev a separate event that emits batch data when this isn't easily accessible in the tx.input
    event SequencerBatchData(uint256 indexed batchSequenceNumber, bytes data);

    /// @dev a valid keyset was added
    event SetValidKeyset(bytes32 indexed keysetHash, bytes keysetBytes);

    /// @dev a keyset was invalidated
    event InvalidateKeyset(bytes32 indexed keysetHash);

    function totalDelayedMessagesRead() external view returns (uint256);

    function bridge() external view returns (IBridge);

    /// @dev The size of the batch header
    // solhint-disable-next-line func-name-mixedcase
    function HEADER_LENGTH() external view returns (uint256);

    /// @dev If the first batch data byte after the header has this bit set,
    ///      the sequencer inbox has authenticated the data. Currently not used.
    // solhint-disable-next-line func-name-mixedcase
    function DATA_AUTHENTICATED_FLAG() external view returns (bytes1);

    function rollup() external view returns (IOwnable);

    function isBatchPoster(address) external view returns (bool);

    struct DasKeySetInfo {
        bool isValidKeyset;
        uint64 creationBlock;
    }

    // https://github.com/ethereum/solidity/issues/11826
    // function maxTimeVariation() external view returns (MaxTimeVariation calldata);
    // function dasKeySetInfo(bytes32) external view returns (DasKeySetInfo calldata);

    /// @notice Remove force inclusion delay after a L1 chainId fork
    function removeDelayAfterFork() external;

    /// @notice Force messages from the delayed inbox to be included in the chain
    ///         Callable by any address, but message can only be force-included after maxTimeVariation.delayBlocks and
    ///         maxTimeVariation.delaySeconds has elapsed. As part of normal behaviour the sequencer will include these
    ///         messages so it's only necessary to call this if the sequencer is down, or not including any delayed messages.
    /// @param _totalDelayedMessagesRead The total number of messages to read up to
    /// @param kind The kind of the last message to be included
    /// @param l1BlockAndTime The l1 block and the l1 timestamp of the last message to be included
    /// @param baseFeeL1 The l1 gas price of the last message to be included
    /// @param sender The sender of the last message to be included
    /// @param messageDataHash The messageDataHash of the last message to be included
    function forceInclusion(
        uint256 _totalDelayedMessagesRead,
        uint8 kind,
        uint64[2] calldata l1BlockAndTime,
        uint256 baseFeeL1,
        address sender,
        bytes32 messageDataHash
    ) external;

    function inboxAccs(uint256 index) external view returns (bytes32);

    function batchCount() external view returns (uint256);

    function isValidKeysetHash(bytes32 ksHash) external view returns (bool);

    /// @notice the creation block is intended to still be available after a keyset is deleted
    function getKeysetCreationBlock(bytes32 ksHash) external view returns (uint256);

    // ---------- BatchPoster functions ----------

    function addSequencerL2BatchFromOrigin(
        uint256 sequenceNumber,
        bytes calldata data,
        uint256 afterDelayedMessagesRead,
        IGasRefunder gasRefunder
    ) external;

    function addSequencerL2Batch(
        uint256 sequenceNumber,
        bytes calldata data,
        uint256 afterDelayedMessagesRead,
        IGasRefunder gasRefunder,
        uint256 prevMessageCount,
        uint256 newMessageCount
    ) external;

    // ---------- onlyRollupOrOwner functions ----------

    /**
     * @notice Set max delay for sequencer inbox
     * @param maxTimeVariation_ the maximum time variation parameters
     */
    function setMaxTimeVariation(MaxTimeVariation memory maxTimeVariation_) external;

    /**
     * @notice Updates whether an address is authorized to be a batch poster at the sequencer inbox
     * @param addr the address
     * @param isBatchPoster_ if the specified address should be authorized as a batch poster
     */
    function setIsBatchPoster(address addr, bool isBatchPoster_) external;

    /**
     * @notice Makes Data Availability Service keyset valid
     * @param keysetBytes bytes of the serialized keyset
     */
    function setValidKeyset(bytes calldata keysetBytes) external;

    /**
     * @notice Invalidates a Data Availability Service keyset
     * @param ksHash hash of the keyset
     */
    function invalidateKeysetHash(bytes32 ksHash) external;

    // ---------- initializer ----------

    function initialize(IBridge bridge_, MaxTimeVariation calldata maxTimeVariation_) external;
}

// File: node_modules/@arbitrum/nitro-contracts/src/bridge/IOwnable.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.4.21 <0.9.0;

interface IOwnable {
    function owner() external view returns (address);
}

// File: node_modules/@arbitrum/nitro-contracts/src/libraries/IGasRefunder.sol



// Copyright 2021-2022, Offchain Labs, Inc.
// For license information, see https://github.com/nitro/blob/master/LICENSE
// SPDX-License-Identifier: BUSL-1.1

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

interface IGasRefunder {
    function onGasSpent(
        address payable spender,
        uint256 gasUsed,
        uint256 calldataSize
    ) external returns (bool success);
}

abstract contract GasRefundEnabled {
    /// @dev this refunds the sender for execution costs of the tx
    /// calldata costs are only refunded if `msg.sender == tx.origin` to guarantee the value refunded relates to charging
    /// for the `tx.input`. this avoids a possible attack where you generate large calldata from a contract and get over-refunded
    modifier refundsGas(IGasRefunder gasRefunder) {
        uint256 startGasLeft = gasleft();
        _;
        if (address(gasRefunder) != address(0)) {
            uint256 calldataSize;
            assembly {
                calldataSize := calldatasize()
            }
            uint256 calldataWords = (calldataSize + 31) / 32;
            // account for the CALLDATACOPY cost of the proxy contract, including the memory expansion cost
            startGasLeft += calldataWords * 6 + (calldataWords**2) / 512;
            // if triggered in a contract call, the spender may be overrefunded by appending dummy data to the call
            // so we check if it is a top level call, which would mean the sender paid calldata as part of tx.input
            // solhint-disable-next-line avoid-tx-origin
            if (msg.sender != tx.origin) {
                // We can't be sure if this calldata came from the top level tx,
                // so to be safe we tell the gas refunder there was no calldata.
                calldataSize = 0;
            }
            gasRefunder.onGasSpent(payable(msg.sender), startGasLeft - gasleft(), calldataSize);
        }
    }
}