// Sources flattened with hardhat v2.4.3 https://hardhat.org

// File contracts/common/lib/RLPReader.sol

// SPDX-License-Identifier: MIT

/*
* @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 {
        uint len;
        uint memPtr;
    }

    struct Iterator {
        RLPItem item;   // Item that's being iterated over.
        uint 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));

        uint ptr = self.nextPtr;
        uint 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) {
        uint 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));

        uint ptr = self.memPtr + _payloadOffset(self.memPtr);
        return Iterator(self, ptr);
    }

    /*
    * @param item RLP encoded bytes
    */
    function rlpLen(RLPItem memory item) internal pure returns (uint) {
        return item.len;
    }

    /*
    * @param item RLP encoded bytes
    */
    function payloadLen(RLPItem memory item) internal pure returns (uint) {
        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));

        uint items = numItems(item);
        RLPItem[] memory result = new RLPItem[](items);

        uint memPtr = item.memPtr + _payloadOffset(item.memPtr);
        uint dataLen;
        for (uint 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;
        uint 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 (uint, uint) {
        uint offset = _payloadOffset(item.memPtr);
        uint memPtr = item.memPtr + offset;
        uint 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) {
        (uint memPtr, uint 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;
        
        uint 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);
        uint result;
        uint 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 (uint) {
        require(item.len > 0 && item.len <= 33);

        uint offset = _payloadOffset(item.memPtr);
        uint len = item.len - offset;

        uint result;
        uint 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 (uint) {
        // one byte prefix
        require(item.len == 33);

        uint result;
        uint memPtr = item.memPtr + 1;
        assembly {
            result := mload(memPtr)
        }

        return result;
    }

    function toBytes(RLPItem memory item) internal pure returns (bytes memory) {
        require(item.len > 0);

        uint offset = _payloadOffset(item.memPtr);
        uint len = item.len - offset; // data length
        bytes memory result = new bytes(len);

        uint 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 (uint) {
        if (item.len == 0) return 0;

        uint count = 0;
        uint currPtr = item.memPtr + _payloadOffset(item.memPtr);
        uint 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(uint memPtr) private pure returns (uint) {
        uint itemLen;
        uint 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(uint memPtr) private pure returns (uint) {
        uint 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(uint src, uint dest, uint len) private pure {
        unchecked {
            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
            uint 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/common/lib/MerklePatriciaProof.sol


pragma solidity ^0.8.0;

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/common/lib/Merkle.sol


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/common/matic-sync/FxBaseRootTunnel.sol


pragma solidity ^0.8.0;



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 bytes;
    using RLPReader for RLPReader.RLPItem;
    using Merkle for bytes32;

    // 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);
    }

    // set fxChildTunnel if not set already
    function setFxChildTunnel(address _fxChildTunnel) public {
        require(fxChildTunnel == address(0x0), "FxBaseRootTunnel: CHILD_TUNNEL_ALREADY_SET");
        fxChildTunnel = _fxChildTunnel;
    }

    /**
     * @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) {
        RLPReader.RLPItem[] memory inputDataRLPList = inputData
            .toRlpItem()
            .toList();

        // checking if exit has already been processed
        // unique exit is identified using hash of (blockNumber, branchMask, receiptLogIndex)
        bytes32 exitHash = keccak256(
            abi.encodePacked(
                inputDataRLPList[2].toUint(), // 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(inputDataRLPList[8].toBytes()), // branchMask
                inputDataRLPList[9].toUint() // receiptLogIndex
            )
        );
        require(
            processedExits[exitHash] == false,
            "FxRootTunnel: EXIT_ALREADY_PROCESSED"
        );
        processedExits[exitHash] = true;

        RLPReader.RLPItem[] memory receiptRLPList = inputDataRLPList[6]
            .toBytes()
            .toRlpItem()
            .toList();
        RLPReader.RLPItem memory logRLP = receiptRLPList[3]
            .toList()[
                inputDataRLPList[9].toUint() // receiptLogIndex
            ];

        RLPReader.RLPItem[] memory logRLPList = logRLP.toList();
        
        // check child tunnel
        require(fxChildTunnel == RLPReader.toAddress(logRLPList[0]), "FxRootTunnel: INVALID_FX_CHILD_TUNNEL");

        // verify receipt inclusion
        require(
            MerklePatriciaProof.verify(
                inputDataRLPList[6].toBytes(), // receipt
                inputDataRLPList[8].toBytes(), // branchMask
                inputDataRLPList[7].toBytes(), // receiptProof
                bytes32(inputDataRLPList[5].toUint()) // receiptRoot
            ),
            "FxRootTunnel: INVALID_RECEIPT_PROOF"
        );

        // verify checkpoint inclusion
        _checkBlockMembershipInCheckpoint(
            inputDataRLPList[2].toUint(), // blockNumber
            inputDataRLPList[3].toUint(), // blockTime
            bytes32(inputDataRLPList[4].toUint()), // txRoot
            bytes32(inputDataRLPList[5].toUint()), // receiptRoot
            inputDataRLPList[0].toUint(), // headerNumber
            inputDataRLPList[1].toBytes() // blockProof
        );

        RLPReader.RLPItem[] memory logTopicRLPList = logRLPList[1].toList(); // topics

        require(
            bytes32(logTopicRLPList[0].toUint()) == SEND_MESSAGE_EVENT_SIG, // topic0 is event sig
            "FxRootTunnel: INVALID_SIGNATURE"
        );

        // received message data
        bytes memory receivedData = logRLPList[2].toBytes();
        (bytes memory message) = abi.decode(receivedData, (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) virtual internal;
}


// File @openzeppelin/contracts/token/ERC20/IERC20.sol@v4.2.0



pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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 `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, 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 `sender` to `recipient` 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 sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @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);
}


// File @openzeppelin/contracts/security/ReentrancyGuard.sol@v4.2.0



pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}


// File @openzeppelin/contracts/utils/Context.sol@v4.2.0



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/security/Pausable.sol@v4.2.0



pragma solidity ^0.8.0;

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}


// File @openzeppelin/contracts/utils/Strings.sol@v4.2.0



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/IERC165.sol@v4.2.0



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 @openzeppelin/contracts/utils/introspection/ERC165.sol@v4.2.0



pragma solidity ^0.8.0;

/**
 * @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/access/AccessControl.sol@v4.2.0



pragma solidity ^0.8.0;



/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    function hasRole(bytes32 role, address account) external view returns (bool);

    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    function grantRole(bytes32 role, address account) external;

    function revokeRole(bytes32 role, address account) external;

    function renounceRole(bytes32 role, address account) external;
}

/**
 * @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 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 {_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 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]{20}) is missing role (0x[0-9a-f]{32})$/
     *
     * _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 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]{20}) is missing role (0x[0-9a-f]{32})$/
     */
    function _checkRole(bytes32 role, address account) internal view {
        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 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 granted `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}.
     * ====
     */
    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 {
        emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);
        _roles[role].adminRole = adminRole;
    }

    function _grantRole(bytes32 role, address account) private {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}


// File contracts/common/AccessControlMixin.sol


pragma solidity 0.8.4;

contract AccessControlMixin is AccessControl {
    string private _revertMsg;
    function _setupContractId(string memory contractId) internal {
        _revertMsg = string(abi.encodePacked(contractId, ": INSUFFICIENT_PERMISSIONS"));
    }

    modifier only(bytes32 role) {
        require(
            hasRole(role, _msgSender()),
            _revertMsg
        );
        _;
    }
}


// File contracts/common/ContextMixin.sol


pragma solidity 0.8.4;

abstract contract ContextMixin {
    function msgSender()
        internal
        view
        returns (address sender)
    {
        if (msg.sender == address(this)) {
            bytes memory array = msg.data;
            uint256 index = msg.data.length;
            assembly {
                // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
                sender := and(
                    mload(add(array, index)),
                    0xffffffffffffffffffffffffffffffffffffffff
                )
            }
        } else {
            sender = msg.sender;
        }
        return sender;
    }
}


// File contracts/ethereum/Moonchest.sol


pragma solidity 0.8.4;






/** 
 * @title Moonchest contract
 */
contract Moonchest is FxBaseRootTunnel, AccessControlMixin, ContextMixin, ReentrancyGuard, Pausable {

    // STATE CONSTANTS
    bytes32 public constant PRICE_ADMIN_ROLE = keccak256("PRICE_ADMIN_ROLE");

    // STATE VARIABLES
    IERC20 private _moonieToken;
    address private _bank;

    uint256 public moonchestPrice;
    uint256 public maxMoonchests;

    // MODIFIERS

    modifier moonchestLimit(uint256 amount) 
    {
        require(amount <= maxMoonchests, "Moonchest: Too many moonchests");
        _;
    }

    // CONSTRUCTOR

    constructor(address moonieToken, address checkpointManager, address fxRoot, address bank)  FxBaseRootTunnel(checkpointManager, fxRoot) Pausable() {
        _moonieToken = IERC20(moonieToken);
        _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
        _bank = bank;
        _pause();
    }

    // EXTERNAL FUNCTIONS

    function openMoonchests(uint256 amount) external nonReentrant whenNotPaused moonchestLimit(amount) {
        require(_moonieToken.transferFrom(msg.sender, _bank, amount * moonchestPrice), "Moonchest: There was a problem with MNY transfer");
        _sendMessageToChild(abi.encode(msg.sender, amount));
    }

    function setBank(address bank) external only(DEFAULT_ADMIN_ROLE) {
        _bank = bank;
    }

    function setMoonchestPrice(uint256 price) external only(PRICE_ADMIN_ROLE) {
        moonchestPrice = price;
    }

    function setMoonchestLimit(uint256 limit) external only(DEFAULT_ADMIN_ROLE) {
        maxMoonchests = limit;
    }

    function pause() external only(DEFAULT_ADMIN_ROLE) {
        _pause();
    }

    function unpause() external only(DEFAULT_ADMIN_ROLE) {
        _unpause();
    }

    // INTERNAL FUNCTIONS

    function _processMessageFromChild(bytes memory data) internal override {
    }

}