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Contract Name:
MerklyRefuel

Contract Source Code:

File 1 of 1 : MerklyRefuel

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


// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @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;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol


// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/IMessagingContext.sol



pragma solidity >=0.8.0;

interface IMessagingContext {
    function isSendingMessage() external view returns (bool);

    function getSendContext() external view returns (uint32 dstEid, address sender);
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/IMessagingChannel.sol



pragma solidity >=0.8.0;

interface IMessagingChannel {
    event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce);
    event PacketNilified(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
    event PacketBurnt(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);

    function eid() external view returns (uint32);

    // this is an emergency function if a message cannot be verified for some reasons
    // required to provide _nextNonce to avoid race condition
    function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external;

    function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;

    function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;

    function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32);

    function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);

    function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64);

    function inboundPayloadHash(
        address _receiver,
        uint32 _srcEid,
        bytes32 _sender,
        uint64 _nonce
    ) external view returns (bytes32);

    function lazyInboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/IMessagingComposer.sol



pragma solidity >=0.8.0;

interface IMessagingComposer {
    event ComposeSent(address from, address to, bytes32 guid, uint16 index, bytes message);
    event ComposeDelivered(address from, address to, bytes32 guid, uint16 index);
    event LzComposeAlert(
        address indexed from,
        address indexed to,
        address indexed executor,
        bytes32 guid,
        uint16 index,
        uint256 gas,
        uint256 value,
        bytes message,
        bytes extraData,
        bytes reason
    );

    function composeQueue(
        address _from,
        address _to,
        bytes32 _guid,
        uint16 _index
    ) external view returns (bytes32 messageHash);

    function sendCompose(address _to, bytes32 _guid, uint16 _index, bytes calldata _message) external;

    function lzCompose(
        address _from,
        address _to,
        bytes32 _guid,
        uint16 _index,
        bytes calldata _message,
        bytes calldata _extraData
    ) external payable;
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/IMessageLibManager.sol



pragma solidity >=0.8.0;

struct SetConfigParam {
    uint32 eid;
    uint32 configType;
    bytes config;
}

interface IMessageLibManager {
    struct Timeout {
        address lib;
        uint256 expiry;
    }

    event LibraryRegistered(address newLib);
    event DefaultSendLibrarySet(uint32 eid, address newLib);
    event DefaultReceiveLibrarySet(uint32 eid, address newLib);
    event DefaultReceiveLibraryTimeoutSet(uint32 eid, address oldLib, uint256 expiry);
    event SendLibrarySet(address sender, uint32 eid, address newLib);
    event ReceiveLibrarySet(address receiver, uint32 eid, address newLib);
    event ReceiveLibraryTimeoutSet(address receiver, uint32 eid, address oldLib, uint256 timeout);

    function registerLibrary(address _lib) external;

    function isRegisteredLibrary(address _lib) external view returns (bool);

    function getRegisteredLibraries() external view returns (address[] memory);

    function setDefaultSendLibrary(uint32 _eid, address _newLib) external;

    function defaultSendLibrary(uint32 _eid) external view returns (address);

    function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint256 _timeout) external;

    function defaultReceiveLibrary(uint32 _eid) external view returns (address);

    function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint256 _expiry) external;

    function defaultReceiveLibraryTimeout(uint32 _eid) external view returns (address lib, uint256 expiry);

    function isSupportedEid(uint32 _eid) external view returns (bool);

    function isValidReceiveLibrary(address _receiver, uint32 _eid, address _lib) external view returns (bool);

    /// ------------------- OApp interfaces -------------------
    function setSendLibrary(address _oapp, uint32 _eid, address _newLib) external;

    function getSendLibrary(address _sender, uint32 _eid) external view returns (address lib);

    function isDefaultSendLibrary(address _sender, uint32 _eid) external view returns (bool);

    function setReceiveLibrary(address _oapp, uint32 _eid, address _newLib, uint256 _gracePeriod) external;

    function getReceiveLibrary(address _receiver, uint32 _eid) external view returns (address lib, bool isDefault);

    function setReceiveLibraryTimeout(address _oapp, uint32 _eid, address _lib, uint256 _gracePeriod) external;

    function receiveLibraryTimeout(address _receiver, uint32 _eid) external view returns (address lib, uint256 expiry);

    function setConfig(address _oapp, address _lib, SetConfigParam[] calldata _params) external;

    function getConfig(
        address _oapp,
        address _lib,
        uint32 _eid,
        uint32 _configType
    ) external view returns (bytes memory config);
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol



pragma solidity >=0.8.0;





struct MessagingParams {
    uint32 dstEid;
    bytes32 receiver;
    bytes message;
    bytes options;
    bool payInLzToken;
}

struct MessagingReceipt {
    bytes32 guid;
    uint64 nonce;
    MessagingFee fee;
}

struct MessagingFee {
    uint256 nativeFee;
    uint256 lzTokenFee;
}

struct Origin {
    uint32 srcEid;
    bytes32 sender;
    uint64 nonce;
}

interface ILayerZeroEndpointV2 is IMessageLibManager, IMessagingComposer, IMessagingChannel, IMessagingContext {
    event PacketSent(bytes encodedPayload, bytes options, address sendLibrary);

    event PacketVerified(Origin origin, address receiver, bytes32 payloadHash);

    event PacketDelivered(Origin origin, address receiver);

    event LzReceiveAlert(
        address indexed receiver,
        address indexed executor,
        Origin origin,
        bytes32 guid,
        uint256 gas,
        uint256 value,
        bytes message,
        bytes extraData,
        bytes reason
    );

    event LzTokenSet(address token);

    event DelegateSet(address sender, address delegate);

    function quote(MessagingParams calldata _params, address _sender) external view returns (MessagingFee memory);

    function send(
        MessagingParams calldata _params,
        address _refundAddress
    ) external payable returns (MessagingReceipt memory);

    function verify(Origin calldata _origin, address _receiver, bytes32 _payloadHash) external;

    function verifiable(Origin calldata _origin, address _receiver) external view returns (bool);

    function initializable(Origin calldata _origin, address _receiver) external view returns (bool);

    function lzReceive(
        Origin calldata _origin,
        address _receiver,
        bytes32 _guid,
        bytes calldata _message,
        bytes calldata _extraData
    ) external payable;

    // oapp can burn messages partially by calling this function with its own business logic if messages are verified in order
    function clear(address _oapp, Origin calldata _origin, bytes32 _guid, bytes calldata _message) external;

    function setLzToken(address _lzToken) external;

    function lzToken() external view returns (address);

    function nativeToken() external view returns (address);

    function setDelegate(address _delegate) external;
}

// File: @layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroReceiver.sol



pragma solidity >=0.8.0;


interface ILayerZeroReceiver {
    function allowInitializePath(Origin calldata _origin) external view returns (bool);

    function nextNonce(uint32 _eid, bytes32 _sender) external view returns (uint64);

    function lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) external payable;
}

// File: oapp/contracts/oapp/interfaces/IOAppCore.sol



pragma solidity ^0.8.20;


/**
 * @title IOAppCore
 */
interface IOAppCore {
    // Custom error messages
    error OnlyPeer(uint32 eid, bytes32 sender);
    error NoPeer(uint32 eid);
    error InvalidEndpointCall();

    // Event emitted when a peer (OApp) is set for a corresponding endpoint
    event PeerSet(uint32 eid, bytes32 peer);

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     */
    function oAppVersion() external view returns (uint64 senderVersion, uint64 receiverVersion);

    /**
     * @notice Retrieves the LayerZero endpoint associated with the OApp.
     * @return iEndpoint The LayerZero endpoint as an interface.
     */
    function endpoint() external view returns (ILayerZeroEndpointV2 iEndpoint);

    /**
     * @notice Retrieves the peer (OApp) associated with a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @return peer The peer address (OApp instance) associated with the corresponding endpoint.
     */
    function peers(uint32 _eid) external view returns (bytes32 peer);

    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     */
    function setPeer(uint32 _eid, bytes32 _peer) external;

    /**
     * @notice Sets the delegate address for the OApp Core.
     * @param _delegate The address of the delegate to be set.
     */
    function setDelegate(address _delegate) external;
}

// File: oapp/contracts/oapp/OAppCore.sol



pragma solidity ^0.8.20;



/**
 * @title OAppCore
 * @dev Abstract contract implementing the IOAppCore interface with basic OApp configurations.
 */
abstract contract OAppCore is IOAppCore, Ownable {
    // The LayerZero endpoint associated with the given OApp
    ILayerZeroEndpointV2 public immutable endpoint;

    // Mapping to store peers associated with corresponding endpoints
    mapping(uint32 eid => bytes32 peer) public peers;

    /**
     * @dev Constructor to initialize the OAppCore with the provided endpoint and owner.
     * @param _endpoint The address of the LOCAL Layer Zero endpoint.
     * @param _owner The address of the owner of the OAppCore.
     */
    constructor(address _endpoint, address _owner) Ownable(_owner) {
        _transferOwnership(_owner);
        endpoint = ILayerZeroEndpointV2(_endpoint);
        endpoint.setDelegate(_owner); // @dev By default, the owner is the delegate
    }

    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
     * @dev Set this to bytes32(0) to remove the peer address.
     * @dev Peer is a bytes32 to accommodate non-evm chains.
     */
    function setPeer(uint32 _eid, bytes32 _peer) public virtual onlyOwner {
        peers[_eid] = _peer;
        emit PeerSet(_eid, _peer);
    }

    /**
     * @notice Internal function to get the peer address associated with a specific endpoint; reverts if NOT set.
     * ie. the peer is set to bytes32(0).
     * @param _eid The endpoint ID.
     * @return peer The address of the peer associated with the specified endpoint.
     */
    function _getPeerOrRevert(uint32 _eid) internal view virtual returns (bytes32) {
        bytes32 peer = peers[_eid];
        if (peer == bytes32(0)) revert NoPeer(_eid);
        return peer;
    }

    /**
     * @notice Sets the delegate address for the OApp.
     * @param _delegate The address of the delegate to be set.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Provides the ability for a delegate to set configs, on behalf of the OApp, directly on the Endpoint contract.
     * @dev Defaults to the owner of the OApp.
     */
    function setDelegate(address _delegate) public onlyOwner {
        endpoint.setDelegate(_delegate);
    }
}

// File: oapp/contracts/oapp/OAppReceiver.sol



pragma solidity ^0.8.20;



/**
 * @title OAppReceiver
 * @dev Abstract contract implementing the ILayerZeroReceiver interface and extending OAppCore for OApp receivers.
 */
abstract contract OAppReceiver is ILayerZeroReceiver, OAppCore {
    // Custom error message for when the caller is not the registered endpoint/
    error OnlyEndpoint(address addr);

    // @dev The version of the OAppReceiver implementation.
    // @dev Version is bumped when changes are made to this contract.
    uint64 internal constant RECEIVER_VERSION = 1;

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     *
     * @dev Providing 0 as the default for OAppSender version. Indicates that the OAppSender is not implemented.
     * ie. this is a SEND only OApp.
     * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions.
     */
    function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
        return (0, RECEIVER_VERSION);
    }

    /**
     * @notice Checks if the path initialization is allowed based on the provided origin.
     * @param origin The origin information containing the source endpoint and sender address.
     * @return Whether the path has been initialized.
     *
     * @dev This indicates to the endpoint that the OApp has enabled msgs for this particular path to be received.
     * @dev This defaults to assuming if a peer has been set, its initialized.
     * Can be overridden by the OApp if there is other logic to determine this.
     */
    function allowInitializePath(Origin calldata origin) public view virtual returns (bool) {
        return peers[origin.srcEid] == origin.sender;
    }

    /**
     * @notice Retrieves the next nonce for a given source endpoint and sender address.
     * @dev _srcEid The source endpoint ID.
     * @dev _sender The sender address.
     * @return nonce The next nonce.
     *
     * @dev The path nonce starts from 1. If 0 is returned it means that there is NO nonce ordered enforcement.
     * @dev Is required by the off-chain executor to determine the OApp expects msg execution is ordered.
     * @dev This is also enforced by the OApp.
     * @dev By default this is NOT enabled. ie. nextNonce is hardcoded to return 0.
     */
    function nextNonce(uint32 /*_srcEid*/, bytes32 /*_sender*/) public view virtual returns (uint64 nonce) {
        return 0;
    }

    /**
     * @dev Entry point for receiving messages or packets from the endpoint.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The payload of the received message.
     * @param _executor The address of the executor for the received message.
     * @param _extraData Additional arbitrary data provided by the corresponding executor.
     *
     * @dev Entry point for receiving msg/packet from the LayerZero endpoint.
     */
    function lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) public payable virtual {
        // Ensures that only the endpoint can attempt to lzReceive() messages to this OApp.
        if (address(endpoint) != msg.sender) revert OnlyEndpoint(msg.sender);

        // Ensure that the sender matches the expected peer for the source endpoint.
        if (_getPeerOrRevert(_origin.srcEid) != _origin.sender) revert OnlyPeer(_origin.srcEid, _origin.sender);

        // Call the internal OApp implementation of lzReceive.
        _lzReceive(_origin, _guid, _message, _executor, _extraData);
    }

    /**
     * @dev Internal function to implement lzReceive logic without needing to copy the basic parameter validation.
     */
    function _lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual;
}

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


// OpenZeppelin Contracts (last updated v5.0.0) (utils/Address.sol)

pragma solidity ^0.8.20;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev The ETH balance of the account is not enough to perform the operation.
     */
    error AddressInsufficientBalance(address account);

    /**
     * @dev There's no code at `target` (it is not a contract).
     */
    error AddressEmptyCode(address target);

    /**
     * @dev A call to an address target failed. The target may have reverted.
     */
    error FailedInnerCall();

    /**
     * @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://consensys.net/diligence/blog/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/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert AddressInsufficientBalance(address(this));
        }

        (bool success, ) = recipient.call{value: amount}("");
        if (!success) {
            revert FailedInnerCall();
        }
    }

    /**
     * @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 or custom error, it is bubbled
     * up by this function (like regular Solidity function calls). However, if
     * the call reverted with no returned reason, this function reverts with a
     * {FailedInnerCall} error.
     *
     * 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.
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @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`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert AddressInsufficientBalance(address(this));
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

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

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

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {FailedInnerCall}) in case of an
     * unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {FailedInnerCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {FailedInnerCall}.
     */
    function _revert(bytes memory returndata) 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 FailedInnerCall();
        }
    }
}

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


// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.20;

/**
 * @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.
 *
 * ==== Security Considerations
 *
 * There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
 * expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
 * considered as an intention to spend the allowance in any specific way. The second is that because permits have
 * built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
 * take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
 * generally recommended is:
 *
 * ```solidity
 * function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
 *     try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
 *     doThing(..., value);
 * }
 *
 * function doThing(..., uint256 value) public {
 *     token.safeTransferFrom(msg.sender, address(this), value);
 *     ...
 * }
 * ```
 *
 * Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
 * `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
 * {SafeERC20-safeTransferFrom}).
 *
 * Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
 * contracts should have entry points that don't rely on permit.
 */
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].
     *
     * CAUTION: See Security Considerations above.
     */
    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: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

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

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

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

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

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

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

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

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

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


// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;




/**
 * @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;

    /**
     * @dev An operation with an ERC20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @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);
        if (returndata.length != 0 && !abi.decode(returndata, (bool))) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // 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 cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return success && (returndata.length == 0 || abi.decode(returndata, (bool))) && address(token).code.length > 0;
    }
}

// File: oapp/contracts/oapp/OAppSender.sol



pragma solidity ^0.8.20;




/**
 * @title OAppSender
 * @dev Abstract contract implementing the OAppSender functionality for sending messages to a LayerZero endpoint.
 */
abstract contract OAppSender is OAppCore {
    using SafeERC20 for IERC20;

    // Custom error messages
    error NotEnoughNative(uint256 msgValue);
    error LzTokenUnavailable();

    // @dev The version of the OAppSender implementation.
    // @dev Version is bumped when changes are made to this contract.
    uint64 internal constant SENDER_VERSION = 1;

    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     *
     * @dev Providing 0 as the default for OAppReceiver version. Indicates that the OAppReceiver is not implemented.
     * ie. this is a RECEIVE only OApp.
     * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions
     */
    function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
        return (SENDER_VERSION, 0);
    }

    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.quote() for fee calculation.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _payInLzToken Flag indicating whether to pay the fee in LZ tokens.
     * @return fee The calculated MessagingFee for the message.
     *      - nativeFee: The native fee for the message.
     *      - lzTokenFee: The LZ token fee for the message.
     */
    function _quote(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        bool _payInLzToken
    ) internal view virtual returns (MessagingFee memory fee) {
        return
            endpoint.quote(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _payInLzToken),
                address(this)
            );
    }

    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.send() for sending a message.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _fee The calculated LayerZero fee for the message.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess fee values sent to the endpoint.
     * @return receipt The receipt for the sent message.
     *      - guid: The unique identifier for the sent message.
     *      - nonce: The nonce of the sent message.
     *      - fee: The LayerZero fee incurred for the message.
     */
    function _lzSend(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        MessagingFee memory _fee,
        address _refundAddress
    ) internal virtual returns (MessagingReceipt memory receipt) {
        // @dev Push corresponding fees to the endpoint, any excess is sent back to the _refundAddress from the endpoint.
        uint256 messageValue = _payNative(_fee.nativeFee);
        if (_fee.lzTokenFee > 0) _payLzToken(_fee.lzTokenFee);

        return
            // solhint-disable-next-line check-send-result
            endpoint.send{ value: messageValue }(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _fee.lzTokenFee > 0),
                _refundAddress
            );
    }

    /**
     * @dev Internal function to pay the native fee associated with the message.
     * @param _nativeFee The native fee to be paid.
     * @return nativeFee The amount of native currency paid.
     *
     * @dev If the OApp needs to initiate MULTIPLE LayerZero messages in a single transaction,
     * this will need to be overridden because msg.value would contain multiple lzFees.
     * @dev Should be overridden in the event the LayerZero endpoint requires a different native currency.
     * @dev Some EVMs use an ERC20 as a method for paying transactions/gasFees.
     * @dev The endpoint is EITHER/OR, ie. it will NOT support both types of native payment at a time.
     */
    function _payNative(uint256 _nativeFee) internal virtual returns (uint256 nativeFee) {
        if (msg.value != _nativeFee) revert NotEnoughNative(msg.value);
        return _nativeFee;
    }

    /**
     * @dev Internal function to pay the LZ token fee associated with the message.
     * @param _lzTokenFee The LZ token fee to be paid.
     *
     * @dev If the caller is trying to pay in the specified lzToken, then the lzTokenFee is passed to the endpoint.
     * @dev Any excess sent, is passed back to the specified _refundAddress in the _lzSend().
     */
    function _payLzToken(uint256 _lzTokenFee) internal virtual {
        // @dev Cannot cache the token because it is not immutable in the endpoint.
        address lzToken = endpoint.lzToken();
        if (lzToken == address(0)) revert LzTokenUnavailable();

        // Pay LZ token fee by sending tokens to the endpoint.
        IERC20(lzToken).safeTransferFrom(msg.sender, address(endpoint), _lzTokenFee);
    }
}

// File: oapp/contracts/oapp/OApp.sol

pragma solidity ^0.8.20;





contract MerklyRefuel is OAppSender, OAppReceiver {
    constructor(address _endpoint) OAppCore(_endpoint, msg.sender) {}

    function bridgeGas(uint32 _dstEid, string memory _message, bytes calldata _options) external payable {
        bytes memory _payload = abi.encodePacked(_message); // Encodes message as bytes.
 
        _lzSend(
            _dstEid, // Destination chain's endpoint ID.
            _payload, // Encoded message payload being sent.
            _options, // Message execution options (e.g., gas to use on destination).
            MessagingFee(msg.value, 0), // Fee struct containing native gas and ZRO token.
            payable(address(this)) // The refund address in case the send call reverts.
        );
    }

    function quote(
        uint32 _dstEid, // Destination chain's endpoint ID.
        string memory _message, // The message to send.
        bytes calldata _options, // Message execution options
        bool _payInLzToken // boolean for which token to return fee in
    ) public view returns (uint256 nativeFee, uint256 lzTokenFee) {
        bytes memory _payload = abi.encodePacked(_message);
        MessagingFee memory fee = _quote(_dstEid, _payload, _options, _payInLzToken);
        return (fee.nativeFee, fee.lzTokenFee);
    }


    function _lzReceive(
        Origin calldata _origin, // struct containing info about the message sender
        bytes32 _guid, // global packet identifier
        bytes calldata payload, // encoded message payload being received
        address _executor, // the Executor address.
        bytes calldata _extraData // arbitrary data appended by the Executor
    ) internal override {
    }



    function oAppVersion()
        public
        pure
        virtual
        override(OAppSender, OAppReceiver)
        returns (uint64 senderVersion, uint64 receiverVersion)
    {
        return (SENDER_VERSION, RECEIVER_VERSION);
    }

    function withdraw() public payable onlyOwner {
        (bool success, ) = payable(msg.sender).call{value: address(this).balance}("");
        require(success);
    }

    fallback() external payable {}

    receive() external payable {}
}

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