// File: contracts/portal/CelestialPortalRoot.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.11;

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

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

/**
 * @title Celestial Portal Root
 * @notice Edited from fx-portal/contracts and EtherOrcsOfficial/etherOrcs-contracts.
 */
contract CelestialPortalRoot is Ownable {
  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;

  /// @notice Emited when we replay a call.
  event CallMade(address target, bool success, bytes data);

  /// @notice Hashed message event -> keccak256("MessageSent(bytes)").
  bytes32 public constant SEND_MESSAGE_EVENT_SIG = 0x8c5261668696ce22758910d05bab8f186d6eb247ceac2af2e82c7dc17669b036;

  /// @notice Fx Root contract address.
  address public fxRoot;
  /// @notice Checkpoint Manager contract address.
  address public checkpointManager;

  /// @notice Polyland Portal contract address.
  address public polylandPortal;

  /// @notice Authorized callers mapping.
  mapping(address => bool) public auth;

  /// @notice Message exits mapping.
  mapping(bytes32 => bool) public processedExits;

  /// @notice Require the sender to be the owner or authorized.
  modifier onlyAuth() {
    require(auth[msg.sender], "CelestialPortalRoot: Unauthorized to use the portal");
    _;
  }

  /// @notice Initialize the contract.
  function initialize(
    address newFxRoot,
    address newCheckpointManager,
    address newPolylandPortal
  ) external onlyOwner {
    fxRoot = newFxRoot;
    checkpointManager = newCheckpointManager;
    polylandPortal = newPolylandPortal;
  }

  /// @notice Give authentication to `adds_`.
  function setAuth(address[] calldata addresses, bool authorized) external onlyOwner {
    for (uint256 index = 0; index < addresses.length; index++) {
      auth[addresses[index]] = authorized;
    }
  }

  /// @notice Send a message to the portal via FxRoot.
  function sendMessage(bytes calldata message) external onlyAuth {
    IFxStateSender(fxRoot).sendMessageToChild(polylandPortal, message);
  }

  /// @notice Clone reflection calls by the owner.
  function replayCall(
    address target_,
    bytes calldata data_,
    bool required_
  ) external onlyOwner {
    (bool succ, ) = target_.call(data_);
    if (required_) require(succ, "CelestialPortalRoot: Replay call failed");
  }

  /**
   * @notice Executed when we receive a message from Polyland.
   * @dev This function verifies if the transaction actually happened on child chain.
   * @param data 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 calldata data) public virtual {
    bytes memory message = _validateAndExtractMessage(data);
    (address target, bytes[] memory calls) = abi.decode(message, (address, bytes[]));
    for (uint256 i = 0; i < calls.length; i++) {
      (bool success, ) = target.call(calls[i]);
      emit CallMade(target, success, calls[i]);
    }
  }

  /// @notice Validate and extract message from FxRoot.
  function _validateAndExtractMessage(bytes memory data) internal returns (bytes memory) {
    ExitPayloadReader.ExitPayload memory payload = data.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, "CelestialPortalRoot: EXIT_ALREADY_PROCESSED");
    processedExits[exitHash] = true;

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

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

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

  /// @notice Validate checkpoint payload.
  function _checkBlockMembershipInCheckpoint(
    uint256 blockNumber,
    uint256 blockTime,
    bytes32 txRoot,
    bytes32 receiptRoot,
    uint256 headerNumber,
    bytes memory blockProof
  ) internal view returns (uint256) {
    (bytes32 headerRoot, uint256 startBlock, , uint256 createdAt, ) = ICheckpointManager(checkpointManager)
      .headerBlocks(headerNumber);

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

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

interface ICheckpointManager {
  function headerBlocks(uint256 headerBlock)
    external
    view
    returns (
      bytes32 root,
      uint256 start,
      uint256 end,
      uint256 createdAt,
      address proposer
    );
}

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



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

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @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.
 *
 * By default, the owner account will be the one that deploys the contract. 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;

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

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

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

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing 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 {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _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: contracts/portal/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/portal/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/portal/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/portal/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];
  }
}

// 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;
    }
}