// File: contracts/state-transfer/FxStateRootTunnel.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.7;

import "@openzeppelin/contracts/access/AccessControl.sol";

import { FxBaseRootTunnel } from "../tunnel/FxBaseRootTunnel.sol";

/**
 * @title FxStateRootTunnel
 */
contract FxStateRootTunnel is FxBaseRootTunnel, AccessControl {
	bytes public latestData;
	address public maticX;

	constructor(
		address _checkpointManager,
		address _fxRoot,
		address _maticX
	) FxBaseRootTunnel(_checkpointManager, _fxRoot) {
		_setupRole(DEFAULT_ADMIN_ROLE, msg.sender);

		maticX = _maticX;
	}

	function _processMessageFromChild(bytes memory data) internal override {
		latestData = data;
	}

	function sendMessageToChild(bytes memory message) public {
		require(msg.sender == maticX, "Not maticX");
		_sendMessageToChild(message);
	}

	function setMaticX(address _maticX) external onlyRole(DEFAULT_ADMIN_ROLE) {
		maticX = _maticX;
	}

	function setFxChildTunnel(address _fxChildTunnel)
		external
		override
		onlyRole(DEFAULT_ADMIN_ROLE)
	{
		fxChildTunnel = _fxChildTunnel;
	}
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(uint160(account), 20),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: contracts/tunnel/FxBaseRootTunnel.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { RLPReader } from "../lib/RLPReader.sol";
import { MerklePatriciaProof } from "../lib/MerklePatriciaProof.sol";
import { Merkle } from "../lib/Merkle.sol";
import "../lib/ExitPayloadReader.sol";

interface IFxStateSender {
	function sendMessageToChild(address _receiver, bytes calldata _data)
		external;
}

contract ICheckpointManager {
	struct HeaderBlock {
		bytes32 root;
		uint256 start;
		uint256 end;
		uint256 createdAt;
		address proposer;
	}

	/**
	 * @notice mapping of checkpoint header numbers to block details
	 * @dev These checkpoints are submited by plasma contracts
	 */
	mapping(uint256 => HeaderBlock) public headerBlocks;
}

abstract contract FxBaseRootTunnel {
	using RLPReader for RLPReader.RLPItem;
	using Merkle for bytes32;
	using ExitPayloadReader for bytes;
	using ExitPayloadReader for ExitPayloadReader.ExitPayload;
	using ExitPayloadReader for ExitPayloadReader.Log;
	using ExitPayloadReader for ExitPayloadReader.LogTopics;
	using ExitPayloadReader for ExitPayloadReader.Receipt;

	// keccak256(MessageSent(bytes))
	bytes32 public constant SEND_MESSAGE_EVENT_SIG =
		0x8c5261668696ce22758910d05bab8f186d6eb247ceac2af2e82c7dc17669b036;

	// state sender contract
	IFxStateSender public fxRoot;
	// root chain manager
	ICheckpointManager public checkpointManager;
	// child tunnel contract which receives and sends messages
	address public fxChildTunnel;

	// storage to avoid duplicate exits
	mapping(bytes32 => bool) public processedExits;

	constructor(address _checkpointManager, address _fxRoot) {
		checkpointManager = ICheckpointManager(_checkpointManager);
		fxRoot = IFxStateSender(_fxRoot);
	}

	function setFxChildTunnel(address _fxChildTunnel) external virtual;

	/**
	 * @notice Send bytes message to Child Tunnel
	 * @param message bytes message that will be sent to Child Tunnel
	 * some message examples -
	 *   abi.encode(tokenId);
	 *   abi.encode(tokenId, tokenMetadata);
	 *   abi.encode(messageType, messageData);
	 */
	function _sendMessageToChild(bytes memory message) internal {
		fxRoot.sendMessageToChild(fxChildTunnel, message);
	}

	function _validateAndExtractMessage(bytes memory inputData)
		internal
		returns (bytes memory)
	{
		ExitPayloadReader.ExitPayload memory payload = inputData
			.toExitPayload();

		bytes memory branchMaskBytes = payload.getBranchMaskAsBytes();
		uint256 blockNumber = payload.getBlockNumber();
		// checking if exit has already been processed
		// unique exit is identified using hash of (blockNumber, branchMask, receiptLogIndex)
		bytes32 exitHash = keccak256(
			abi.encodePacked(
				blockNumber,
				// first 2 nibbles are dropped while generating nibble array
				// this allows branch masks that are valid but bypass exitHash check (changing first 2 nibbles only)
				// so converting to nibble array and then hashing it
				MerklePatriciaProof._getNibbleArray(branchMaskBytes),
				payload.getReceiptLogIndex()
			)
		);
		require(
			processedExits[exitHash] == false,
			"FxRootTunnel: EXIT_ALREADY_PROCESSED"
		);
		processedExits[exitHash] = true;

		ExitPayloadReader.Receipt memory receipt = payload.getReceipt();
		ExitPayloadReader.Log memory log = receipt.getLog();

		// check child tunnel
		require(
			fxChildTunnel == log.getEmitter(),
			"FxRootTunnel: INVALID_FX_CHILD_TUNNEL"
		);

		bytes32 receiptRoot = payload.getReceiptRoot();
		// verify receipt inclusion
		require(
			MerklePatriciaProof.verify(
				receipt.toBytes(),
				branchMaskBytes,
				payload.getReceiptProof(),
				receiptRoot
			),
			"FxRootTunnel: INVALID_RECEIPT_PROOF"
		);

		// verify checkpoint inclusion
		_checkBlockMembershipInCheckpoint(
			blockNumber,
			payload.getBlockTime(),
			payload.getTxRoot(),
			receiptRoot,
			payload.getHeaderNumber(),
			payload.getBlockProof()
		);

		ExitPayloadReader.LogTopics memory topics = log.getTopics();

		require(
			bytes32(topics.getField(0).toUint()) == SEND_MESSAGE_EVENT_SIG, // topic0 is event sig
			"FxRootTunnel: INVALID_SIGNATURE"
		);

		// received message data
		bytes memory message = abi.decode(log.getData(), (bytes)); // event decodes params again, so decoding bytes to get message
		return message;
	}

	function _checkBlockMembershipInCheckpoint(
		uint256 blockNumber,
		uint256 blockTime,
		bytes32 txRoot,
		bytes32 receiptRoot,
		uint256 headerNumber,
		bytes memory blockProof
	) private view returns (uint256) {
		(
			bytes32 headerRoot,
			uint256 startBlock,
			,
			uint256 createdAt,

		) = checkpointManager.headerBlocks(headerNumber);

		require(
			keccak256(
				abi.encodePacked(blockNumber, blockTime, txRoot, receiptRoot)
			).checkMembership(blockNumber - startBlock, headerRoot, blockProof),
			"FxRootTunnel: INVALID_HEADER"
		);
		return createdAt;
	}

	/**
	 * @notice receive message from  L2 to L1, validated by proof
	 * @dev This function verifies if the transaction actually happened on child chain
	 *
	 * @param inputData RLP encoded data of the reference tx containing following list of fields
	 *  0 - headerNumber - Checkpoint header block number containing the reference tx
	 *  1 - blockProof - Proof that the block header (in the child chain) is a leaf in the submitted merkle root
	 *  2 - blockNumber - Block number containing the reference tx on child chain
	 *  3 - blockTime - Reference tx block time
	 *  4 - txRoot - Transactions root of block
	 *  5 - receiptRoot - Receipts root of block
	 *  6 - receipt - Receipt of the reference transaction
	 *  7 - receiptProof - Merkle proof of the reference receipt
	 *  8 - branchMask - 32 bits denoting the path of receipt in merkle tree
	 *  9 - receiptLogIndex - Log Index to read from the receipt
	 */
	function receiveMessage(bytes memory inputData) public virtual {
		bytes memory message = _validateAndExtractMessage(inputData);
		_processMessageFromChild(message);
	}

	/**
	 * @notice Process message received from Child Tunnel
	 * @dev function needs to be implemented to handle message as per requirement
	 * This is called by onStateReceive function.
	 * Since it is called via a system call, any event will not be emitted during its execution.
	 * @param message bytes message that was sent from Child Tunnel
	 */
	function _processMessageFromChild(bytes memory message) internal virtual;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

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



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

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



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



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

pragma solidity ^0.8.0;

/**
 * @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: contracts/lib/RLPReader.sol



/*
 * @author Hamdi Allam hamdi.allam97@gmail.com
 * Please reach out with any questions or concerns
 */
pragma solidity ^0.8.0;

library RLPReader {
	uint8 constant STRING_SHORT_START = 0x80;
	uint8 constant STRING_LONG_START = 0xb8;
	uint8 constant LIST_SHORT_START = 0xc0;
	uint8 constant LIST_LONG_START = 0xf8;
	uint8 constant WORD_SIZE = 32;

	struct RLPItem {
		uint256 len;
		uint256 memPtr;
	}

	struct Iterator {
		RLPItem item; // Item that's being iterated over.
		uint256 nextPtr; // Position of the next item in the list.
	}

	/*
	 * @dev Returns the next element in the iteration. Reverts if it has not next element.
	 * @param self The iterator.
	 * @return The next element in the iteration.
	 */
	function next(Iterator memory self) internal pure returns (RLPItem memory) {
		require(hasNext(self));

		uint256 ptr = self.nextPtr;
		uint256 itemLength = _itemLength(ptr);
		self.nextPtr = ptr + itemLength;

		return RLPItem(itemLength, ptr);
	}

	/*
	 * @dev Returns true if the iteration has more elements.
	 * @param self The iterator.
	 * @return true if the iteration has more elements.
	 */
	function hasNext(Iterator memory self) internal pure returns (bool) {
		RLPItem memory item = self.item;
		return self.nextPtr < item.memPtr + item.len;
	}

	/*
	 * @param item RLP encoded bytes
	 */
	function toRlpItem(bytes memory item)
		internal
		pure
		returns (RLPItem memory)
	{
		uint256 memPtr;
		assembly {
			memPtr := add(item, 0x20)
		}

		return RLPItem(item.length, memPtr);
	}

	/*
	 * @dev Create an iterator. Reverts if item is not a list.
	 * @param self The RLP item.
	 * @return An 'Iterator' over the item.
	 */
	function iterator(RLPItem memory self)
		internal
		pure
		returns (Iterator memory)
	{
		require(isList(self));

		uint256 ptr = self.memPtr + _payloadOffset(self.memPtr);
		return Iterator(self, ptr);
	}

	/*
	 * @param item RLP encoded bytes
	 */
	function rlpLen(RLPItem memory item) internal pure returns (uint256) {
		return item.len;
	}

	/*
	 * @param item RLP encoded bytes
	 */
	function payloadLen(RLPItem memory item) internal pure returns (uint256) {
		return item.len - _payloadOffset(item.memPtr);
	}

	/*
	 * @param item RLP encoded list in bytes
	 */
	function toList(RLPItem memory item)
		internal
		pure
		returns (RLPItem[] memory)
	{
		require(isList(item));

		uint256 items = numItems(item);
		RLPItem[] memory result = new RLPItem[](items);

		uint256 memPtr = item.memPtr + _payloadOffset(item.memPtr);
		uint256 dataLen;
		for (uint256 i = 0; i < items; i++) {
			dataLen = _itemLength(memPtr);
			result[i] = RLPItem(dataLen, memPtr);
			memPtr = memPtr + dataLen;
		}

		return result;
	}

	// @return indicator whether encoded payload is a list. negate this function call for isData.
	function isList(RLPItem memory item) internal pure returns (bool) {
		if (item.len == 0) return false;

		uint8 byte0;
		uint256 memPtr = item.memPtr;
		assembly {
			byte0 := byte(0, mload(memPtr))
		}

		if (byte0 < LIST_SHORT_START) return false;
		return true;
	}

	/*
	 * @dev A cheaper version of keccak256(toRlpBytes(item)) that avoids copying memory.
	 * @return keccak256 hash of RLP encoded bytes.
	 */
	function rlpBytesKeccak256(RLPItem memory item)
		internal
		pure
		returns (bytes32)
	{
		uint256 ptr = item.memPtr;
		uint256 len = item.len;
		bytes32 result;
		assembly {
			result := keccak256(ptr, len)
		}
		return result;
	}

	function payloadLocation(RLPItem memory item)
		internal
		pure
		returns (uint256, uint256)
	{
		uint256 offset = _payloadOffset(item.memPtr);
		uint256 memPtr = item.memPtr + offset;
		uint256 len = item.len - offset; // data length
		return (memPtr, len);
	}

	/*
	 * @dev A cheaper version of keccak256(toBytes(item)) that avoids copying memory.
	 * @return keccak256 hash of the item payload.
	 */
	function payloadKeccak256(RLPItem memory item)
		internal
		pure
		returns (bytes32)
	{
		(uint256 memPtr, uint256 len) = payloadLocation(item);
		bytes32 result;
		assembly {
			result := keccak256(memPtr, len)
		}
		return result;
	}

	/** RLPItem conversions into data types **/

	// @returns raw rlp encoding in bytes
	function toRlpBytes(RLPItem memory item)
		internal
		pure
		returns (bytes memory)
	{
		bytes memory result = new bytes(item.len);
		if (result.length == 0) return result;

		uint256 ptr;
		assembly {
			ptr := add(0x20, result)
		}

		copy(item.memPtr, ptr, item.len);
		return result;
	}

	// any non-zero byte is considered true
	function toBoolean(RLPItem memory item) internal pure returns (bool) {
		require(item.len == 1);
		uint256 result;
		uint256 memPtr = item.memPtr;
		assembly {
			result := byte(0, mload(memPtr))
		}

		return result == 0 ? false : true;
	}

	function toAddress(RLPItem memory item) internal pure returns (address) {
		// 1 byte for the length prefix
		require(item.len == 21);

		return address(uint160(toUint(item)));
	}

	function toUint(RLPItem memory item) internal pure returns (uint256) {
		require(item.len > 0 && item.len <= 33);

		uint256 offset = _payloadOffset(item.memPtr);
		uint256 len = item.len - offset;

		uint256 result;
		uint256 memPtr = item.memPtr + offset;
		assembly {
			result := mload(memPtr)

			// shfit to the correct location if neccesary
			if lt(len, 32) {
				result := div(result, exp(256, sub(32, len)))
			}
		}

		return result;
	}

	// enforces 32 byte length
	function toUintStrict(RLPItem memory item) internal pure returns (uint256) {
		// one byte prefix
		require(item.len == 33);

		uint256 result;
		uint256 memPtr = item.memPtr + 1;
		assembly {
			result := mload(memPtr)
		}

		return result;
	}

	function toBytes(RLPItem memory item) internal pure returns (bytes memory) {
		require(item.len > 0);

		uint256 offset = _payloadOffset(item.memPtr);
		uint256 len = item.len - offset; // data length
		bytes memory result = new bytes(len);

		uint256 destPtr;
		assembly {
			destPtr := add(0x20, result)
		}

		copy(item.memPtr + offset, destPtr, len);
		return result;
	}

	/*
	 * Private Helpers
	 */

	// @return number of payload items inside an encoded list.
	function numItems(RLPItem memory item) private pure returns (uint256) {
		if (item.len == 0) return 0;

		uint256 count = 0;
		uint256 currPtr = item.memPtr + _payloadOffset(item.memPtr);
		uint256 endPtr = item.memPtr + item.len;
		while (currPtr < endPtr) {
			currPtr = currPtr + _itemLength(currPtr); // skip over an item
			count++;
		}

		return count;
	}

	// @return entire rlp item byte length
	function _itemLength(uint256 memPtr) private pure returns (uint256) {
		uint256 itemLen;
		uint256 byte0;
		assembly {
			byte0 := byte(0, mload(memPtr))
		}

		if (byte0 < STRING_SHORT_START) itemLen = 1;
		else if (byte0 < STRING_LONG_START)
			itemLen = byte0 - STRING_SHORT_START + 1;
		else if (byte0 < LIST_SHORT_START) {
			assembly {
				let byteLen := sub(byte0, 0xb7) // # of bytes the actual length is
				memPtr := add(memPtr, 1) // skip over the first byte
				/* 32 byte word size */
				let dataLen := div(mload(memPtr), exp(256, sub(32, byteLen))) // right shifting to get the len
				itemLen := add(dataLen, add(byteLen, 1))
			}
		} else if (byte0 < LIST_LONG_START) {
			itemLen = byte0 - LIST_SHORT_START + 1;
		} else {
			assembly {
				let byteLen := sub(byte0, 0xf7)
				memPtr := add(memPtr, 1)

				let dataLen := div(mload(memPtr), exp(256, sub(32, byteLen))) // right shifting to the correct length
				itemLen := add(dataLen, add(byteLen, 1))
			}
		}

		return itemLen;
	}

	// @return number of bytes until the data
	function _payloadOffset(uint256 memPtr) private pure returns (uint256) {
		uint256 byte0;
		assembly {
			byte0 := byte(0, mload(memPtr))
		}

		if (byte0 < STRING_SHORT_START) return 0;
		else if (
			byte0 < STRING_LONG_START ||
			(byte0 >= LIST_SHORT_START && byte0 < LIST_LONG_START)
		) return 1;
		else if (byte0 < LIST_SHORT_START)
			// being explicit
			return byte0 - (STRING_LONG_START - 1) + 1;
		else return byte0 - (LIST_LONG_START - 1) + 1;
	}

	/*
	 * @param src Pointer to source
	 * @param dest Pointer to destination
	 * @param len Amount of memory to copy from the source
	 */
	function copy(
		uint256 src,
		uint256 dest,
		uint256 len
	) private pure {
		if (len == 0) return;

		// copy as many word sizes as possible
		for (; len >= WORD_SIZE; len -= WORD_SIZE) {
			assembly {
				mstore(dest, mload(src))
			}

			src += WORD_SIZE;
			dest += WORD_SIZE;
		}

		if (len == 0) return;

		// left over bytes. Mask is used to remove unwanted bytes from the word
		uint256 mask = 256**(WORD_SIZE - len) - 1;

		assembly {
			let srcpart := and(mload(src), not(mask)) // zero out src
			let destpart := and(mload(dest), mask) // retrieve the bytes
			mstore(dest, or(destpart, srcpart))
		}
	}
}

// File: contracts/lib/MerklePatriciaProof.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import { RLPReader } from "./RLPReader.sol";

library MerklePatriciaProof {
	/*
	 * @dev Verifies a merkle patricia proof.
	 * @param value The terminating value in the trie.
	 * @param encodedPath The path in the trie leading to value.
	 * @param rlpParentNodes The rlp encoded stack of nodes.
	 * @param root The root hash of the trie.
	 * @return The boolean validity of the proof.
	 */
	function verify(
		bytes memory value,
		bytes memory encodedPath,
		bytes memory rlpParentNodes,
		bytes32 root
	) internal pure returns (bool) {
		RLPReader.RLPItem memory item = RLPReader.toRlpItem(rlpParentNodes);
		RLPReader.RLPItem[] memory parentNodes = RLPReader.toList(item);

		bytes memory currentNode;
		RLPReader.RLPItem[] memory currentNodeList;

		bytes32 nodeKey = root;
		uint256 pathPtr = 0;

		bytes memory path = _getNibbleArray(encodedPath);
		if (path.length == 0) {
			return false;
		}

		for (uint256 i = 0; i < parentNodes.length; i++) {
			if (pathPtr > path.length) {
				return false;
			}

			currentNode = RLPReader.toRlpBytes(parentNodes[i]);
			if (nodeKey != keccak256(currentNode)) {
				return false;
			}
			currentNodeList = RLPReader.toList(parentNodes[i]);

			if (currentNodeList.length == 17) {
				if (pathPtr == path.length) {
					if (
						keccak256(RLPReader.toBytes(currentNodeList[16])) ==
						keccak256(value)
					) {
						return true;
					} else {
						return false;
					}
				}

				uint8 nextPathNibble = uint8(path[pathPtr]);
				if (nextPathNibble > 16) {
					return false;
				}
				nodeKey = bytes32(
					RLPReader.toUintStrict(currentNodeList[nextPathNibble])
				);
				pathPtr += 1;
			} else if (currentNodeList.length == 2) {
				uint256 traversed = _nibblesToTraverse(
					RLPReader.toBytes(currentNodeList[0]),
					path,
					pathPtr
				);
				if (pathPtr + traversed == path.length) {
					//leaf node
					if (
						keccak256(RLPReader.toBytes(currentNodeList[1])) ==
						keccak256(value)
					) {
						return true;
					} else {
						return false;
					}
				}

				//extension node
				if (traversed == 0) {
					return false;
				}

				pathPtr += traversed;
				nodeKey = bytes32(RLPReader.toUintStrict(currentNodeList[1]));
			} else {
				return false;
			}
		}
	}

	function _nibblesToTraverse(
		bytes memory encodedPartialPath,
		bytes memory path,
		uint256 pathPtr
	) private pure returns (uint256) {
		uint256 len = 0;
		// encodedPartialPath has elements that are each two hex characters (1 byte), but partialPath
		// and slicedPath have elements that are each one hex character (1 nibble)
		bytes memory partialPath = _getNibbleArray(encodedPartialPath);
		bytes memory slicedPath = new bytes(partialPath.length);

		// pathPtr counts nibbles in path
		// partialPath.length is a number of nibbles
		for (uint256 i = pathPtr; i < pathPtr + partialPath.length; i++) {
			bytes1 pathNibble = path[i];
			slicedPath[i - pathPtr] = pathNibble;
		}

		if (keccak256(partialPath) == keccak256(slicedPath)) {
			len = partialPath.length;
		} else {
			len = 0;
		}
		return len;
	}

	// bytes b must be hp encoded
	function _getNibbleArray(bytes memory b)
		internal
		pure
		returns (bytes memory)
	{
		bytes memory nibbles = "";
		if (b.length > 0) {
			uint8 offset;
			uint8 hpNibble = uint8(_getNthNibbleOfBytes(0, b));
			if (hpNibble == 1 || hpNibble == 3) {
				nibbles = new bytes(b.length * 2 - 1);
				bytes1 oddNibble = _getNthNibbleOfBytes(1, b);
				nibbles[0] = oddNibble;
				offset = 1;
			} else {
				nibbles = new bytes(b.length * 2 - 2);
				offset = 0;
			}

			for (uint256 i = offset; i < nibbles.length; i++) {
				nibbles[i] = _getNthNibbleOfBytes(i - offset + 2, b);
			}
		}
		return nibbles;
	}

	function _getNthNibbleOfBytes(uint256 n, bytes memory str)
		private
		pure
		returns (bytes1)
	{
		return
			bytes1(
				n % 2 == 0 ? uint8(str[n / 2]) / 0x10 : uint8(str[n / 2]) % 0x10
			);
	}
}

// File: contracts/lib/Merkle.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

library Merkle {
	function checkMembership(
		bytes32 leaf,
		uint256 index,
		bytes32 rootHash,
		bytes memory proof
	) internal pure returns (bool) {
		require(proof.length % 32 == 0, "Invalid proof length");
		uint256 proofHeight = proof.length / 32;
		// Proof of size n means, height of the tree is n+1.
		// In a tree of height n+1, max #leafs possible is 2 ^ n
		require(index < 2**proofHeight, "Leaf index is too big");

		bytes32 proofElement;
		bytes32 computedHash = leaf;
		for (uint256 i = 32; i <= proof.length; i += 32) {
			assembly {
				proofElement := mload(add(proof, i))
			}

			if (index % 2 == 0) {
				computedHash = keccak256(
					abi.encodePacked(computedHash, proofElement)
				);
			} else {
				computedHash = keccak256(
					abi.encodePacked(proofElement, computedHash)
				);
			}

			index = index / 2;
		}
		return computedHash == rootHash;
	}
}

// File: contracts/lib/ExitPayloadReader.sol



pragma solidity ^0.8.0;

import { RLPReader } from "./RLPReader.sol";

library ExitPayloadReader {
	using RLPReader for bytes;
	using RLPReader for RLPReader.RLPItem;

	uint8 constant WORD_SIZE = 32;

	struct ExitPayload {
		RLPReader.RLPItem[] data;
	}

	struct Receipt {
		RLPReader.RLPItem[] data;
		bytes raw;
		uint256 logIndex;
	}

	struct Log {
		RLPReader.RLPItem data;
		RLPReader.RLPItem[] list;
	}

	struct LogTopics {
		RLPReader.RLPItem[] data;
	}

	// copy paste of private copy() from RLPReader to avoid changing of existing contracts
	function copy(
		uint256 src,
		uint256 dest,
		uint256 len
	) private pure {
		if (len == 0) return;

		// copy as many word sizes as possible
		for (; len >= WORD_SIZE; len -= WORD_SIZE) {
			assembly {
				mstore(dest, mload(src))
			}

			src += WORD_SIZE;
			dest += WORD_SIZE;
		}

		// left over bytes. Mask is used to remove unwanted bytes from the word
		uint256 mask = 256**(WORD_SIZE - len) - 1;
		assembly {
			let srcpart := and(mload(src), not(mask)) // zero out src
			let destpart := and(mload(dest), mask) // retrieve the bytes
			mstore(dest, or(destpart, srcpart))
		}
	}

	function toExitPayload(bytes memory data)
		internal
		pure
		returns (ExitPayload memory)
	{
		RLPReader.RLPItem[] memory payloadData = data.toRlpItem().toList();

		return ExitPayload(payloadData);
	}

	function getHeaderNumber(ExitPayload memory payload)
		internal
		pure
		returns (uint256)
	{
		return payload.data[0].toUint();
	}

	function getBlockProof(ExitPayload memory payload)
		internal
		pure
		returns (bytes memory)
	{
		return payload.data[1].toBytes();
	}

	function getBlockNumber(ExitPayload memory payload)
		internal
		pure
		returns (uint256)
	{
		return payload.data[2].toUint();
	}

	function getBlockTime(ExitPayload memory payload)
		internal
		pure
		returns (uint256)
	{
		return payload.data[3].toUint();
	}

	function getTxRoot(ExitPayload memory payload)
		internal
		pure
		returns (bytes32)
	{
		return bytes32(payload.data[4].toUint());
	}

	function getReceiptRoot(ExitPayload memory payload)
		internal
		pure
		returns (bytes32)
	{
		return bytes32(payload.data[5].toUint());
	}

	function getReceipt(ExitPayload memory payload)
		internal
		pure
		returns (Receipt memory receipt)
	{
		receipt.raw = payload.data[6].toBytes();
		RLPReader.RLPItem memory receiptItem = receipt.raw.toRlpItem();

		if (receiptItem.isList()) {
			// legacy tx
			receipt.data = receiptItem.toList();
		} else {
			// pop first byte before parsting receipt
			bytes memory typedBytes = receipt.raw;
			bytes memory result = new bytes(typedBytes.length - 1);
			uint256 srcPtr;
			uint256 destPtr;
			assembly {
				srcPtr := add(33, typedBytes)
				destPtr := add(0x20, result)
			}

			copy(srcPtr, destPtr, result.length);
			receipt.data = result.toRlpItem().toList();
		}

		receipt.logIndex = getReceiptLogIndex(payload);
		return receipt;
	}

	function getReceiptProof(ExitPayload memory payload)
		internal
		pure
		returns (bytes memory)
	{
		return payload.data[7].toBytes();
	}

	function getBranchMaskAsBytes(ExitPayload memory payload)
		internal
		pure
		returns (bytes memory)
	{
		return payload.data[8].toBytes();
	}

	function getBranchMaskAsUint(ExitPayload memory payload)
		internal
		pure
		returns (uint256)
	{
		return payload.data[8].toUint();
	}

	function getReceiptLogIndex(ExitPayload memory payload)
		internal
		pure
		returns (uint256)
	{
		return payload.data[9].toUint();
	}

	// Receipt methods
	function toBytes(Receipt memory receipt)
		internal
		pure
		returns (bytes memory)
	{
		return receipt.raw;
	}

	function getLog(Receipt memory receipt) internal pure returns (Log memory) {
		RLPReader.RLPItem memory logData = receipt.data[3].toList()[
			receipt.logIndex
		];
		return Log(logData, logData.toList());
	}

	// Log methods
	function getEmitter(Log memory log) internal pure returns (address) {
		return RLPReader.toAddress(log.list[0]);
	}

	function getTopics(Log memory log)
		internal
		pure
		returns (LogTopics memory)
	{
		return LogTopics(log.list[1].toList());
	}

	function getData(Log memory log) internal pure returns (bytes memory) {
		return log.list[2].toBytes();
	}

	function toRlpBytes(Log memory log) internal pure returns (bytes memory) {
		return log.data.toRlpBytes();
	}

	// LogTopics methods
	function getField(LogTopics memory topics, uint256 index)
		internal
		pure
		returns (RLPReader.RLPItem memory)
	{
		return topics.data[index];
	}
}