Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: UNLICENSED
// A Sample ISMP solidity contract for unit tests

pragma solidity ^0.8.17;

import {BaseIsmpModule, IncomingPostRequest} from "@polytope-labs/ismp-solidity/IIsmpModule.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {DispatchPost, IDispatcher, PostRequest} from "@polytope-labs/ismp-solidity/IDispatcher.sol";

struct CrossChainMessage {
    bytes dest;
    bytes message;
    uint256 relayerFee;
    uint64 timeout;
}

contract CrossChainInscription is BaseIsmpModule {
    using SafeERC20 for IERC20;

    // An inscription has been received
    event PostReceived(string message);

    // An inscription has been received
    event PostDispatched(string message, bytes32 commitment);

    // An inscription has been received
    event PostTimedOut(string message);

    // Call is unauthorized
    error Unauthorized();

    address private _admin;
    address private _host;

    constructor(address admin) {
        _admin = admin;
    }

    function setHost(address host) public {
        if (msg.sender != _admin) revert Unauthorized();
        // infinite approval to save on gas
        IERC20(IDispatcher(host).feeToken()).approve(
            host,
            type(uint256).max
        );

        _host = host;
        _admin = address(0);
    }

    function inscribe(CrossChainMessage memory params) public payable {
        DispatchPost memory request = DispatchPost({
            body: params.message,
            dest: params.dest,
            timeout: params.timeout,
            // instance of this pallet on another chain.
            to: abi.encodePacked(address(this)),
            fee: params.relayerFee,
            payer: address(this)
        });

        bytes32 commitment;
        if (msg.value > 0) {
            // there's some native tokens left to pay for request dispatch
            commitment = IDispatcher(_host).dispatch{value: msg.value}(request);
        } else {
            // try to pay for dispatch with fee token
            uint256 length = 32 > params.message.length ? 32 : params.message.length;
            uint256 fee = (IDispatcher(_host).perByteFee(params.dest) * length) + params.relayerFee;
            IERC20(IDispatcher(_host).feeToken()).safeTransferFrom(msg.sender, address(this), fee);
            commitment = IDispatcher(_host).dispatch(request);
        }

        emit PostDispatched(string(params.message), commitment);
    }

    function onAccept(IncomingPostRequest memory incoming) external override {
        if (msg.sender != _host) revert UnauthorizedCall();
        emit PostReceived(string(incoming.request.body));
    }

    function onPostRequestTimeout(PostRequest calldata request) external override {
        if (msg.sender != _host) revert UnauthorizedCall();
        emit PostTimedOut(string(request.body));
    }
}

// Copyright (C) Polytope Labs Ltd.
// SPDX-License-Identifier: Apache-2.0
// 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 ^0.8.17;

import {PostRequest, PostResponse, GetResponse, GetRequest} from "./Message.sol";
import {DispatchPost, DispatchPostResponse, DispatchGet, IDispatcher} from "./IDispatcher.sol";

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

struct IncomingPostRequest {
	// The Post request
	PostRequest request;
	// Relayer responsible for delivering the request
	address relayer;
}

struct IncomingPostResponse {
	// The Post response
	PostResponse response;
	// Relayer responsible for delivering the response
	address relayer;
}

struct IncomingGetResponse {
	// The Get response
	GetResponse response;
	// Relayer responsible for delivering the response
	address relayer;
}

interface IIsmpModule {
	/**
	 * @dev Called by the `IsmpHost` to notify a module of a new request the module may choose to respond immediately, or in a later block
	 * @param incoming post request
	 */
	function onAccept(IncomingPostRequest memory incoming) external;

	/**
	 * @dev Called by the `IsmpHost` to notify a module of a post response to a previously sent out request
	 * @param incoming post response
	 */
	function onPostResponse(IncomingPostResponse memory incoming) external;

	/**
	 * @dev Called by the `IsmpHost` to notify a module of a get response to a previously sent out request
	 * @param incoming get response
	 */
	function onGetResponse(IncomingGetResponse memory incoming) external;

	/**
	 * @dev Called by the `IsmpHost` to notify a module of post requests that were previously sent but have now timed-out
	 * @param request post request
	 */
	function onPostRequestTimeout(PostRequest memory request) external;

	/**
	 * @dev Called by the `IsmpHost` to notify a module of post requests that were previously sent but have now timed-out
	 * @param request post request
	 */
	function onPostResponseTimeout(PostResponse memory request) external;

	/**
	 * @dev Called by the `IsmpHost` to notify a module of get requests that were previously sent but have now timed-out
	 * @param request get request
	 */
	function onGetTimeout(GetRequest memory request) external;
}

// @notice Abstract contract to make implementing `IIsmpModule` easier.
abstract contract BaseIsmpModule is IIsmpModule {
	// @notice Call was not expected
	error UnexpectedCall();

	// @notice Account is unauthorized
	error UnauthorizedCall();

	// @dev restricts caller to the local `IsmpHost`
	modifier onlyHost() {
		if (msg.sender != host()) revert UnauthorizedCall();
		_;
	}

	constructor() {
		address hostAddr = host();
		if (hostAddr != address(0)) {
			// approve the host infintely
			IERC20(IDispatcher(hostAddr).feeToken()).approve(hostAddr, type(uint256).max);
		}
	}

	// @dev Returns the `IsmpHost` address for the current chain.
	// The `IsmpHost` is an immutable contract that will never change.
	function host() public view returns (address h) {
		assembly {
			switch chainid()
			// Ethereum Sepolia
			case 11155111 {
				h := 0x27B0c6960B792a8dCb01F0652bDE48015cd5f23e
			}
			// Arbitrum Sepolia
			case 421614 {
				h := 0xfd7E2b2ad0b29Ec817dC7d406881b225B81dbFCf
			}
			// Optimism Sepolia
			case 11155420 {
				h := 0x30e3af1747B155F37F935E0EC995De5EA4e67586
			}
			// Base Sepolia
			case 84532 {
				h := 0x0D7037bd9CEAEF25e5215f808d309ADD0A65Cdb9
			}
			// Binance Smart Chain Testnet
			case 97 {
				h := 0x4cB0f5750f6fE14d4B86acA6fe126943bdA3c8c4
			}
			// Gnosis Chiado Testnet
			case 10200 {
				h := 0x11EB87c745D97a4Fa8Aec805359837459d240d1b
			}
		}
	}

	// @dev returns the quoted fee for a dispatch
	function quote(DispatchPost memory post) public view returns (uint256) {
		return post.fee + (post.body.length * IDispatcher(host()).perByteFee(post.dest));
	}

	// @dev returns the quoted fee for a dispatch
	function quote(DispatchPostResponse memory res) public view returns (uint256) {
		return res.fee + (res.response.length * IDispatcher(host()).perByteFee(res.request.source));
	}

	function onAccept(IncomingPostRequest calldata) external virtual onlyHost {
		revert UnexpectedCall();
	}

	function onPostRequestTimeout(PostRequest memory) external virtual onlyHost {
		revert UnexpectedCall();
	}

	function onPostResponse(IncomingPostResponse memory) external virtual onlyHost {
		revert UnexpectedCall();
	}

	function onPostResponseTimeout(PostResponse memory) external virtual onlyHost {
		revert UnexpectedCall();
	}

	function onGetResponse(IncomingGetResponse memory) external virtual onlyHost {
		revert UnexpectedCall();
	}

	function onGetTimeout(GetRequest memory) external virtual onlyHost {
		revert UnexpectedCall();
	}
}

// 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);
}

// 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");
        }
    }
}

// Copyright (C) Polytope Labs Ltd.
// SPDX-License-Identifier: Apache-2.0
// 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 ^0.8.17;

import {PostRequest, StateMachineHeight} from "./Message.sol";

// @notice An object for dispatching post requests to the Hyperbridge
struct DispatchPost {
	// bytes representation of the destination state machine
	bytes dest;
	// the destination module
	bytes to;
	// the request body
	bytes body;
	// timeout for this request in seconds
	uint64 timeout;
	// the amount put up to be paid to the relayer,
	// this is charged in `IIsmpHost.feeToken` to `msg.sender`
	uint256 fee;
	// who pays for this request?
	address payer;
}

// @notice An object for dispatching get requests to the Hyperbridge
struct DispatchGet {
	// bytes representation of the destination state machine
	bytes dest;
	// height at which to read the state machine
	uint64 height;
	// storage keys to read
	bytes[] keys;
	// timeout for this request in seconds
	uint64 timeout;
	// Hyperbridge protocol fees for processing this request.
	uint256 fee;
	// Some application-specific metadata relating to this request
	bytes context;
}

struct DispatchPostResponse {
	// The request that initiated this response
	PostRequest request;
	// bytes for post response
	bytes response;
	// timeout for this response in seconds
	uint64 timeout;
	// the amount put up to be paid to the relayer,
	// this is charged in `IIsmpHost.feeToken` to `msg.sender`
	uint256 fee;
	// who pays for this request?
	address payer;
}

/*
 * @title The Ismp Dispatcher
 * @author Polytope Labs ([email protected])
 *
 * @notice The IDispatcher serves as the interface requests & response messages.
 */
interface IDispatcher {
	/**
	 * @dev Returns the address for the Uniswap V2 Router implementation used for swaps
	 * @return routerAddress - The address to the in-use RouterV02 implementation
	 */
	function uniswapV2Router() external view returns (address);

	/**
	 * @dev Returns the nonce immediately available for requests
	 * @return the `nonce`
	 */
	function nonce() external view returns (uint256);

	/**
	 * @dev Returns the address of the ERC-20 fee token contract configured for this state machine.
	 *
	 * @notice Hyperbridge collects it's dispatch fees in the provided token denomination. This will typically be in stablecoins.
	 *
	 * @return feeToken - The ERC20 contract address for fees.
	 */
	function feeToken() external view returns (address);

	/**
	 * @dev Returns the address of the per byte fee configured for the destination state machine.
	 *
	 * @notice Hyperbridge collects it's dispatch fees per every byte of the outgoing message.
	 *
	 * @param dest - The destination chain for the per byte fee.
	 * @return perByteFee - The per byte fee for outgoing messages.
	 */
	function perByteFee(bytes memory dest) external view returns (uint256);

	/**
	 * @dev Dispatch a POST request to Hyperbridge
	 *
	 * @notice Payment for the request can be made with either the native token or the IIsmpHost.feeToken.
	 * If native tokens are supplied, it will perform a swap under the hood using the local uniswap router.
	 * Will revert if enough native tokens are not provided.
	 *
	 * If no native tokens are provided then it will try to collect payment from the calling contract in
	 * the IIsmpHost.feeToken.
	 *
	 * @param request - post request
	 * @return commitment - the request commitment
	 */
	function dispatch(DispatchPost memory request) external payable returns (bytes32 commitment);

	/**
	 * @dev Dispatch a GET request to Hyperbridge
	 *
	 * @notice Payment for the request can be made with either the native token or the IIsmpHost.feeToken.
	 * If native tokens are supplied, it will perform a swap under the hood using the local uniswap router.
	 * Will revert if enough native tokens are not provided.
	 *
	 * If no native tokens are provided then it will try to collect payment from the calling contract in
	 * the IIsmpHost.feeToken.
	 *
	 * @param request - get request
	 * @return commitment - the request commitment
	 */
	function dispatch(DispatchGet memory request) external payable returns (bytes32 commitment);

	/**
	 * @dev Dispatch a POST response to Hyperbridge
	 *
	 * @notice Payment for the request can be made with either the native token or the IIsmpHost.feeToken.
	 * If native tokens are supplied, it will perform a swap under the hood using the local uniswap router.
	 * Will revert if enough native tokens are not provided.
	 *
	 * If no native tokens are provided then it will try to collect payment from the calling contract in
	 * the IIsmpHost.feeToken.
	 *
	 * @param response - post response
	 * @return commitment - the request commitment
	 */
	function dispatch(DispatchPostResponse memory response) external payable returns (bytes32 commitment);

	/**
	 * @dev Increase the relayer fee for a previously dispatched request.
	 * This is provided for use only on pending requests, such that when they timeout,
	 * the user can recover the entire relayer fee.
	 *
	 * @notice Payment can be made with either the native token or the IIsmpHost.feeToken.
	 * If native tokens are supplied, it will perform a swap under the hood using the local uniswap router.
	 * Will revert if enough native tokens are not provided.
	 *
	 * If no native tokens are provided then it will try to collect payment from the calling contract in
	 * the IIsmpHost.feeToken.
	 *
	 * If called on an already delivered request, these funds will be seen as a donation to the hyperbridge protocol.
	 * @param commitment - The request commitment
	 * @param amount - The amount provided in `IIsmpHost.feeToken()`
	 */
	function fundRequest(bytes32 commitment, uint256 amount) external payable;

	/**
	 * @dev Increase the relayer fee for a previously dispatched response.
	 * This is provided for use only on pending responses, such that when they timeout,
	 * the user can recover the entire relayer fee.
	 *
	 * @notice Payment can be made with either the native token or the IIsmpHost.feeToken.
	 * If native tokens are supplied, it will perform a swap under the hood using the local uniswap router.
	 * Will revert if enough native tokens are not provided.
	 *
	 * If no native tokens are provided then it will try to collect payment from the calling contract in
	 * the IIsmpHost.feeToken.
	 *
	 * If called on an already delivered response, these funds will be seen as a donation to the hyperbridge protocol.
	 * @param commitment - The response commitment
	 * @param amount - The amount to be provided in `IIsmpHost.feeToken()`
	 */
	function fundResponse(bytes32 commitment, uint256 amount) external payable;
}

// Copyright (C) Polytope Labs Ltd.
// SPDX-License-Identifier: Apache-2.0
// 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 ^0.8.17;

import {StorageValue} from "@polytope-labs/solidity-merkle-trees/src/Types.sol";

// Identifies some state machine height. We allow for a state machine identifier here
// as some consensus clients may track multiple, concurrent state machines.
struct StateMachineHeight {
	// the state machine identifier
	uint256 stateMachineId;
	// height of this state machine
	uint256 height;
}

struct PostRequest {
	// the source state machine of this request
	bytes source;
	// the destination state machine of this request
	bytes dest;
	// request nonce
	uint64 nonce;
	// Module Id of this request origin
	bytes from;
	// destination module id
	bytes to;
	// timestamp by which this request times out.
	uint64 timeoutTimestamp;
	// request body
	bytes body;
}

struct GetRequest {
	// the source state machine of this request
	bytes source;
	// the destination state machine of this request
	bytes dest;
	// request nonce
	uint64 nonce;
	// Module Id of this request origin
	address from;
	// timestamp by which this request times out.
	uint64 timeoutTimestamp;
	// Storage keys to read.
	bytes[] keys;
	// height at which to read destination state machine
	uint64 height;
	// Some application-specific metadata relating to this request
	bytes context;
}

struct GetResponse {
	// The request that initiated this response
	GetRequest request;
	// storage values for get response
	StorageValue[] values;
}

struct PostResponse {
	// The request that initiated this response
	PostRequest request;
	// bytes for post response
	bytes response;
	// timestamp by which this response times out.
	uint64 timeoutTimestamp;
}

// A post request as a leaf in a merkle tree
struct PostRequestLeaf {
	// The request
	PostRequest request;
	// It's index in the mmr leaves
	uint256 index;
	// it's k-index
	uint256 kIndex;
}

// A post response as a leaf in a merkle tree
struct PostResponseLeaf {
	// The response
	PostResponse response;
	// It's index in the mmr leaves
	uint256 index;
	// it's k-index
	uint256 kIndex;
}

// A get response as a leaf in a merkle mountain range tree
struct GetResponseLeaf {
	// The response
	GetResponse response;
	// It's index in the mmr leaves
	uint256 index;
	// it's k-index
	uint256 kIndex;
}

// A merkle mountain range proof.
struct Proof {
	// height of the state machine
	StateMachineHeight height;
	// the multi-proof
	bytes32[] multiproof;
	// The total number of leaves in the mmr for this proof.
	uint256 leafCount;
}

// A message for handling incoming requests
struct PostRequestMessage {
	// proof for the requests
	Proof proof;
	// The requests, contained in the merkle mountain range tree
	PostRequestLeaf[] requests;
}

// A message for handling incoming GET responses
struct GetResponseMessage {
	// proof for the responses
	Proof proof;
	// The responses, contained in the merkle mountain range tree
	GetResponseLeaf[] responses;
}

struct GetTimeoutMessage {
	// requests which have timed-out
	GetRequest[] timeouts;
	// the height of the state machine proof
	StateMachineHeight height;
	// non-membership proof of the requests
	bytes[] proof;
}

struct PostRequestTimeoutMessage {
	// requests which have timed-out
	PostRequest[] timeouts;
	// the height of the state machine proof
	StateMachineHeight height;
	// non-membership proof of the requests
	bytes[] proof;
}

struct PostResponseTimeoutMessage {
	// responses which have timed-out
	PostResponse[] timeouts;
	// the height of the state machine proof
	StateMachineHeight height;
	// non-membership proof of the requests
	bytes[] proof;
}

// A message for handling incoming responses
struct PostResponseMessage {
	// proof for the responses
	Proof proof;
	// the responses, contained in a merkle tree leaf
	PostResponseLeaf[] responses;
}

library Message {
	/**
	 * @dev Calculates the absolute timeout value for a PostRequest
	 */
	function timeout(PostRequest memory req) internal pure returns (uint64) {
		if (req.timeoutTimestamp == 0) {
			return type(uint64).max;
		} else {
			return req.timeoutTimestamp;
		}
	}

	/**
	 * @dev Calculates the absolute timeout value for a GetRequest
	 */
	function timeout(GetRequest memory req) internal pure returns (uint64) {
		if (req.timeoutTimestamp == 0) {
			return type(uint64).max;
		} else {
			return req.timeoutTimestamp;
		}
	}

	/**
	 * @dev Calculates the absolute timeout value for a PostResponse
	 */
	function timeout(PostResponse memory res) internal pure returns (uint64) {
		if (res.timeoutTimestamp == 0) {
			return type(uint64).max;
		} else {
			return res.timeoutTimestamp;
		}
	}

	/**
	 * @dev Encode the given post request for commitment
	 */
	function encode(PostRequest memory req) internal pure returns (bytes memory) {
		return abi.encodePacked(req.source, req.dest, req.nonce, req.timeoutTimestamp, req.from, req.to, req.body);
	}

	/**
	 * @dev Encode the given get request for commitment
	 */
	function encode(GetRequest memory req) internal pure returns (bytes memory) {
		bytes memory keysEncoding = bytes("");
		uint256 len = req.keys.length;
		for (uint256 i = 0; i < len; i++) {
			keysEncoding = bytes.concat(keysEncoding, req.keys[i]);
		}

		return
			abi.encodePacked(
				req.source,
				req.dest,
				req.nonce,
				req.height,
				req.timeoutTimestamp,
				abi.encodePacked(req.from),
				keysEncoding,
				req.context
			);
	}

	/**
	 * @dev Returns the commitment for the given post response
	 */
	function hash(PostResponse memory res) internal pure returns (bytes32) {
		return keccak256(bytes.concat(encode(res.request), abi.encodePacked(res.response, res.timeoutTimestamp)));
	}

	/**
	 * @dev Returns the commitment for the given post request
	 */
	function hash(PostRequest memory req) internal pure returns (bytes32) {
		return keccak256(encode(req));
	}

	/**
	 * @dev Returns the commitment for the given get request
	 */
	function hash(GetRequest memory req) internal pure returns (bytes32) {
		return keccak256(encode(req));
	}

	/**
	 * @dev Returns the commitment for the given get response
	 */
	function hash(GetResponse memory res) internal pure returns (bytes32) {
		bytes memory response = bytes("");
		uint256 len = res.values.length;
		for (uint256 i = 0; i < len; i++) {
			response = bytes.concat(response, bytes.concat(res.values[i].key, res.values[i].value));
		}
		return keccak256(bytes.concat(encode(res.request), response));
	}
}

// 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);
}

// 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);
        }
    }
}

pragma solidity ^0.8.17;

// SPDX-License-Identifier: Apache2

// Outcome of a successfully verified merkle-patricia proof
struct StorageValue {
    // the storage key
    bytes key;
    // the encoded value
    bytes value;
}

/// @title A representation of a Merkle tree node
struct Node {
    // Distance of the node to the leftmost node
    uint256 k_index;
    // A hash of the node itself
    bytes32 node;
}

/// @title A representation of a MerkleMountainRange leaf
struct MmrLeaf {
    // the leftmost index of a node
    uint256 k_index;
    // The position in the tree
    uint256 leaf_index;
    // The hash of the position in the tree
    bytes32 hash;
}

struct Iterator {
    uint256 offset;
    bytes32[] data;
}