// File: src/main/VestaNFT.sol



// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/utils/cryptography/MerkleProof.sol";
import "@openzeppelin/contracts/utils/Base64.sol";

import "./interfaces/IVestaNFT.sol";
import "./layerzero/ONFT721.sol";

contract VestaNFT is ONFT721, IVestaNFT {
	string public contractURI;
	string[] private URIs;

	uint256[] private offsetTierIds = [0, 1_000_000, 2_000_000];
	uint256[] private nextTokenIds;

	bytes32 public merkleRoot;

	mapping(bytes32 => bool) internal claimed;

	constructor(
		string memory _name,
		string memory _symbol,
		address _layerZeroEndpoint,
		string[] memory _uris,
		string memory _contractURI
	) ONFT721(_name, _symbol, _layerZeroEndpoint) {
		nextTokenIds = new uint256[](3);
		URIs = _uris;
		contractURI = _contractURI;
	}

	function setCollectionDescription(string memory _contractURI)
		external
		onlyOwner
	{
		contractURI = _contractURI;
	}

	function setMerkleRoot(bytes32 _newRoot) external onlyOwner {
		if (_newRoot == bytes32(0)) {
			revert ZeroMerkleRootPassed();
		}
		merkleRoot = _newRoot;
		emit MerkleRootChanged(_newRoot);
	}

	function hasClaimedNFT(address _user, uint8 _tier)
		external
		view
		override
		returns (bool)
	{
		return claimed[keccak256(abi.encodePacked(_user, _tier))];
	}

	function claimNFT(bytes32[] calldata _merkleProof, uint8 _tier)
		external
		override
	{
		//Removed, Arbitrum (0xe3c5D8349473Fe81a259257a5B5019493F98C217) is the only one with this option
	}

	function _mint(uint8 _tier) internal {
		uint256 tokenId = offsetTierIds[_tier] + nextTokenIds[_tier];
		nextTokenIds[_tier] += 1;

		_safeMint(msg.sender, tokenId);
		_setTokenURI(tokenId, URIs[_tier]);

		emit NFTClaimed(msg.sender, _tier);
	}

	function _creditTo(
		uint16,
		address _toAddress,
		uint256 _tokenId
	) internal override {
		uint256 offsetTier2 = offsetTierIds[2];
		uint256 tier = 0;

		if (_tokenId >= offsetTierIds[1] && _tokenId < offsetTier2) {
			tier = 1;
		} else if (_tokenId >= offsetTier2) {
			tier = 2;
		}

		_safeMint(_toAddress, _tokenId);
		_setTokenURI(_tokenId, URIs[tier]);
	}
}

// File: @openzeppelin/contracts/utils/cryptography/MerkleProof.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 *
 * WARNING: You should avoid using leaf values that are 64 bytes long prior to
 * hashing, or use a hash function other than keccak256 for hashing leaves.
 * This is because the concatenation of a sorted pair of internal nodes in
 * the merkle tree could be reinterpreted as a leaf value.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merkle tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}

// File: @openzeppelin/contracts/utils/Base64.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (utils/Base64.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides a set of functions to operate with Base64 strings.
 *
 * _Available since v4.5._
 */
library Base64 {
    /**
     * @dev Base64 Encoding/Decoding Table
     */
    string internal constant _TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

    /**
     * @dev Converts a `bytes` to its Bytes64 `string` representation.
     */
    function encode(bytes memory data) internal pure returns (string memory) {
        /**
         * Inspired by Brecht Devos (Brechtpd) implementation - MIT licence
         * https://github.com/Brechtpd/base64/blob/e78d9fd951e7b0977ddca77d92dc85183770daf4/base64.sol
         */
        if (data.length == 0) return "";

        // Loads the table into memory
        string memory table = _TABLE;

        // Encoding takes 3 bytes chunks of binary data from `bytes` data parameter
        // and split into 4 numbers of 6 bits.
        // The final Base64 length should be `bytes` data length multiplied by 4/3 rounded up
        // - `data.length + 2`  -> Round up
        // - `/ 3`              -> Number of 3-bytes chunks
        // - `4 *`              -> 4 characters for each chunk
        string memory result = new string(4 * ((data.length + 2) / 3));

        assembly {
            // Prepare the lookup table (skip the first "length" byte)
            let tablePtr := add(table, 1)

            // Prepare result pointer, jump over length
            let resultPtr := add(result, 32)

            // Run over the input, 3 bytes at a time
            for {
                let dataPtr := data
                let endPtr := add(data, mload(data))
            } lt(dataPtr, endPtr) {

            } {
                // Advance 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // To write each character, shift the 3 bytes (18 bits) chunk
                // 4 times in blocks of 6 bits for each character (18, 12, 6, 0)
                // and apply logical AND with 0x3F which is the number of
                // the previous character in the ASCII table prior to the Base64 Table
                // The result is then added to the table to get the character to write,
                // and finally write it in the result pointer but with a left shift
                // of 256 (1 byte) - 8 (1 ASCII char) = 248 bits

                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(shr(6, input), 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance

                mstore8(resultPtr, mload(add(tablePtr, and(input, 0x3F))))
                resultPtr := add(resultPtr, 1) // Advance
            }

            // When data `bytes` is not exactly 3 bytes long
            // it is padded with `=` characters at the end
            switch mod(mload(data), 3)
            case 1 {
                mstore8(sub(resultPtr, 1), 0x3d)
                mstore8(sub(resultPtr, 2), 0x3d)
            }
            case 2 {
                mstore8(sub(resultPtr, 1), 0x3d)
            }
        }

        return result;
    }
}

// File: src/main/interfaces/IVestaNFT.sol



// SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.4;

interface IVestaNFT {
	error AlreadyClaimed(address _caller, uint8 _tier);
	error InvalidMerkleProof(address _caller, uint8 _tier);
	error ZeroMerkleRootPassed();
	error MerkleRootNotInitialized();

	event MerkleRootChanged(bytes32 _merkleRoot);
	event NFTClaimed(address _addr, uint8 _tier);

	/** 
	@notice setMerkleRoot is used to define who is eligible for the NFT airdrop
	@dev onlyOwner can execute this function
	@param _newRoot Generated Merkle Root of the eligible users
	*/
	function setMerkleRoot(bytes32 _newRoot) external;

	/** 
	@notice hasClaimedNFT to verify if a wallet already claimed a specific NFT Tier
	@param _user user wallet
	@param _tier V-Card tier
	@return hasBeenClaimed returns true if the user already claimed it
	*/
	function hasClaimedNFT(address _user, uint8 _tier)
		external
		view
		returns (bool);

	/** 
	@notice claimNFT to mint the nft by tier via a merkle proof
	@param _merkleProof generated merkle proof
	@param _tier V-Card tier
	*/
	function claimNFT(bytes32[] calldata _merkleProof, uint8 _tier) external;
}

// File: src/main/layerzero/ONFT721.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../interfaces/layerzero/IONFT721.sol";
import "./ONFT721Core.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";

// NOTE: this ONFT contract has no public minting logic.
// must implement your own minting logic in child classes
abstract contract ONFT721 is ONFT721Core, ERC721URIStorage, IONFT721 {
	constructor(
		string memory _name,
		string memory _symbol,
		address _lzEndpoint
	) ERC721(_name, _symbol) ONFT721Core(_lzEndpoint) {}

	function supportsInterface(bytes4 interfaceId)
		public
		view
		virtual
		override(ONFT721Core, ERC721, IERC165)
		returns (bool)
	{
		return
			interfaceId == type(IONFT721).interfaceId ||
			super.supportsInterface(interfaceId);
	}

	function _debitFrom(
		address _from,
		uint16,
		bytes memory,
		uint256 _tokenId
	) internal virtual override {
		require(
			_isApprovedOrOwner(_msgSender(), _tokenId),
			"ONFT721: send caller is not owner nor approved"
		);
		require(
			ERC721.ownerOf(_tokenId) == _from,
			"ONFT721: send from incorrect owner"
		);
		_burn(_tokenId);
	}
}

// File: src/main/interfaces/layerzero/IONFT721.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IONFT721Core.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";

/**
 * @dev Interface of the ONFT standard
 */
interface IONFT721 is IONFT721Core, IERC721 {

}

// File: src/main/layerzero/ONFT721Core.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../interfaces/layerzero/IONFT721Core.sol";
import "./NonblockingLzApp.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";

abstract contract ONFT721Core is NonblockingLzApp, ERC165, IONFT721Core {
	constructor(address _lzEndpoint) NonblockingLzApp(_lzEndpoint) {}

	function supportsInterface(bytes4 interfaceId)
		public
		view
		virtual
		override(ERC165, IERC165)
		returns (bool)
	{
		return
			interfaceId == type(IONFT721Core).interfaceId ||
			super.supportsInterface(interfaceId);
	}

	function estimateSendFee(
		uint16 _dstChainId,
		bytes memory _toAddress,
		uint256 _tokenId,
		bool _useZro,
		bytes memory _adapterParams
	)
		public
		view
		virtual
		override
		returns (uint256 nativeFee, uint256 zroFee)
	{
		// mock the payload for send()
		bytes memory payload = abi.encode(_toAddress, _tokenId);
		return
			lzEndpoint.estimateFees(
				_dstChainId,
				address(this),
				payload,
				_useZro,
				_adapterParams
			);
	}

	function sendFrom(
		address _from,
		uint16 _dstChainId,
		bytes memory _toAddress,
		uint256 _tokenId,
		address payable _refundAddress,
		address _zroPaymentAddress,
		bytes memory _adapterParams
	) public payable virtual override {
		_send(
			_from,
			_dstChainId,
			_toAddress,
			_tokenId,
			_refundAddress,
			_zroPaymentAddress,
			_adapterParams
		);
	}

	function _send(
		address _from,
		uint16 _dstChainId,
		bytes memory _toAddress,
		uint256 _tokenId,
		address payable _refundAddress,
		address _zroPaymentAddress,
		bytes memory _adapterParams
	) internal virtual {
		_debitFrom(_from, _dstChainId, _toAddress, _tokenId);

		bytes memory payload = abi.encode(_toAddress, _tokenId);
		_lzSend(
			_dstChainId,
			payload,
			_refundAddress,
			_zroPaymentAddress,
			_adapterParams
		);

		uint64 nonce = lzEndpoint.getOutboundNonce(_dstChainId, address(this));
		emit SendToChain(_from, _dstChainId, _toAddress, _tokenId, nonce);
	}

	function _nonblockingLzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) internal virtual override {
		// decode and load the toAddress
		(bytes memory toAddressBytes, uint256 tokenId) = abi.decode(
			_payload,
			(bytes, uint256)
		);
		address toAddress;
		assembly {
			toAddress := mload(add(toAddressBytes, 20))
		}

		_creditTo(_srcChainId, toAddress, tokenId);

		emit ReceiveFromChain(
			_srcChainId,
			_srcAddress,
			toAddress,
			tokenId,
			_nonce
		);
	}

	function _debitFrom(
		address _from,
		uint16 _dstChainId,
		bytes memory _toAddress,
		uint256 _tokenId
	) internal virtual;

	function _creditTo(
		uint16 _srcChainId,
		address _toAddress,
		uint256 _tokenId
	) internal virtual;
}

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721URIStorage.sol)

pragma solidity ^0.8.0;

import "../ERC721.sol";

/**
 * @dev ERC721 token with storage based token URI management.
 */
abstract contract ERC721URIStorage is ERC721 {
    using Strings for uint256;

    // Optional mapping for token URIs
    mapping(uint256 => string) private _tokenURIs;

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721URIStorage: URI query for nonexistent token");

        string memory _tokenURI = _tokenURIs[tokenId];
        string memory base = _baseURI();

        // If there is no base URI, return the token URI.
        if (bytes(base).length == 0) {
            return _tokenURI;
        }
        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
        if (bytes(_tokenURI).length > 0) {
            return string(abi.encodePacked(base, _tokenURI));
        }

        return super.tokenURI(tokenId);
    }

    /**
     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
        require(_exists(tokenId), "ERC721URIStorage: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual override {
        super._burn(tokenId);

        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
    }
}

// File: src/main/interfaces/layerzero/IONFT721Core.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

/**
 * @dev Interface of the ONFT Core standard
 */
interface IONFT721Core is IERC165 {
	/**
	 * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
	 * _dstChainId - L0 defined chain id to send tokens too
	 * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
	 * _tokenId - token Id to transfer
	 * _useZro - indicates to use zro to pay L0 fees
	 * _adapterParams - flexible bytes array to indicate messaging adapter services in L0
	 */
	function estimateSendFee(
		uint16 _dstChainId,
		bytes calldata _toAddress,
		uint256 _tokenId,
		bool _useZro,
		bytes calldata _adapterParams
	) external view returns (uint256 nativeFee, uint256 zroFee);

	/**
	 * @dev send token `_tokenId` to (`_dstChainId`, `_toAddress`) from `_from`
	 * `_toAddress` can be any size depending on the `dstChainId`.
	 * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
	 * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
	 */
	function sendFrom(
		address _from,
		uint16 _dstChainId,
		bytes calldata _toAddress,
		uint256 _tokenId,
		address payable _refundAddress,
		address _zroPaymentAddress,
		bytes calldata _adapterParams
	) external payable;

	/**
	 * @dev Emitted when `_tokenId` are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
	 * `_nonce` is the outbound nonce from
	 */
	event SendToChain(
		address indexed _sender,
		uint16 indexed _dstChainId,
		bytes indexed _toAddress,
		uint256 _tokenId,
		uint64 _nonce
	);

	/**
	 * @dev Emitted when `_tokenId` are sent from `_srcChainId` to the `_toAddress` at this chain. `_nonce` is the inbound nonce.
	 */
	event ReceiveFromChain(
		uint16 indexed _srcChainId,
		bytes indexed _srcAddress,
		address indexed _toAddress,
		uint256 _tokenId,
		uint64 _nonce
	);
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// 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: src/main/layerzero/NonblockingLzApp.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./LzApp.sol";

/*
 * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
 * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
 * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
 */
abstract contract NonblockingLzApp is LzApp {
	constructor(address _endpoint) LzApp(_endpoint) {}

	mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32)))
		public failedMessages;

	event MessageFailed(
		uint16 _srcChainId,
		bytes _srcAddress,
		uint64 _nonce,
		bytes _payload
	);

	// overriding the virtual function in LzReceiver
	function _blockingLzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) internal virtual override {
		// try-catch all errors/exceptions
		try
			this.nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload)
		{
			// do nothing
		} catch {
			// error / exception
			failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(
				_payload
			);
			emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload);
		}
	}

	function nonblockingLzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) public virtual {
		// only internal transaction
		require(
			_msgSender() == address(this),
			"NonblockingLzApp: caller must be LzApp"
		);
		_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
	}

	//@notice override this function
	function _nonblockingLzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) internal virtual;

	function retryMessage(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) public payable virtual {
		// assert there is message to retry
		bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
		require(
			payloadHash != bytes32(0),
			"NonblockingLzApp: no stored message"
		);
		require(
			keccak256(_payload) == payloadHash,
			"NonblockingLzApp: invalid payload"
		);
		// clear the stored message
		failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
		// execute the message. revert if it fails again
		_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
	}
}

// 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: src/main/layerzero/LzApp.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/layerzero/ILayerZeroReceiver.sol";
import "../interfaces/layerzero/ILayerZeroUserApplicationConfig.sol";
import "../interfaces/layerzero/ILayerZeroEndpoint.sol";

/*
 * a generic LzReceiver implementation
 */
abstract contract LzApp is
	Ownable,
	ILayerZeroReceiver,
	ILayerZeroUserApplicationConfig
{
	ILayerZeroEndpoint public immutable lzEndpoint;

	mapping(uint16 => bytes) public trustedRemoteLookup;

	event SetTrustedRemote(uint16 _srcChainId, bytes _srcAddress);

	constructor(address _endpoint) {
		lzEndpoint = ILayerZeroEndpoint(_endpoint);
	}

	function lzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) public virtual override {
		// lzReceive must be called by the endpoint for security
		require(
			_msgSender() == address(lzEndpoint),
			"LzApp: invalid endpoint caller"
		);

		bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
		// if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
		require(
			_srcAddress.length == trustedRemote.length &&
				keccak256(_srcAddress) == keccak256(trustedRemote),
			"LzApp: invalid source sending contract"
		);

		_blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
	}

	// abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
	function _blockingLzReceive(
		uint16 _srcChainId,
		bytes memory _srcAddress,
		uint64 _nonce,
		bytes memory _payload
	) internal virtual;

	function _lzSend(
		uint16 _dstChainId,
		bytes memory _payload,
		address payable _refundAddress,
		address _zroPaymentAddress,
		bytes memory _adapterParams
	) internal virtual {
		bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
		require(
			trustedRemote.length != 0,
			"LzApp: destination chain is not a trusted source"
		);
		lzEndpoint.send{ value: msg.value }(
			_dstChainId,
			trustedRemote,
			_payload,
			_refundAddress,
			_zroPaymentAddress,
			_adapterParams
		);
	}

	//---------------------------UserApplication config----------------------------------------
	function getConfig(
		uint16 _version,
		uint16 _chainId,
		address,
		uint256 _configType
	) external view returns (bytes memory) {
		return
			lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
	}

	// generic config for LayerZero user Application
	function setConfig(
		uint16 _version,
		uint16 _chainId,
		uint256 _configType,
		bytes calldata _config
	) external override onlyOwner {
		lzEndpoint.setConfig(_version, _chainId, _configType, _config);
	}

	function setSendVersion(uint16 _version) external override onlyOwner {
		lzEndpoint.setSendVersion(_version);
	}

	function setReceiveVersion(uint16 _version) external override onlyOwner {
		lzEndpoint.setReceiveVersion(_version);
	}

	function forceResumeReceive(
		uint16 _srcChainId,
		bytes calldata _srcAddress
	) external override onlyOwner {
		lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
	}

	// allow owner to set it multiple times.
	function setTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress)
		external
		onlyOwner
	{
		trustedRemoteLookup[_srcChainId] = _srcAddress;
		emit SetTrustedRemote(_srcChainId, _srcAddress);
	}

	//--------------------------- VIEW FUNCTION ----------------------------------------

	function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress)
		external
		view
		returns (bool)
	{
		bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
		return keccak256(trustedSource) == keccak256(_srcAddress);
	}
}

// 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: src/main/interfaces/layerzero/ILayerZeroReceiver.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroReceiver {
	// @notice LayerZero endpoint will invoke this function to deliver the message on the destination
	// @param _srcChainId - the source endpoint identifier
	// @param _srcAddress - the source sending contract address from the source chain
	// @param _nonce - the ordered message nonce
	// @param _payload - the signed payload is the UA bytes has encoded to be sent
	function lzReceive(
		uint16 _srcChainId,
		bytes calldata _srcAddress,
		uint64 _nonce,
		bytes calldata _payload
	) external;
}

// File: src/main/interfaces/layerzero/ILayerZeroUserApplicationConfig.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroUserApplicationConfig {
	// @notice set the configuration of the LayerZero messaging library of the specified version
	// @param _version - messaging library version
	// @param _chainId - the chainId for the pending config change
	// @param _configType - type of configuration. every messaging library has its own convention.
	// @param _config - configuration in the bytes. can encode arbitrary content.
	function setConfig(
		uint16 _version,
		uint16 _chainId,
		uint256 _configType,
		bytes calldata _config
	) external;

	// @notice set the send() LayerZero messaging library version to _version
	// @param _version - new messaging library version
	function setSendVersion(uint16 _version) external;

	// @notice set the lzReceive() LayerZero messaging library version to _version
	// @param _version - new messaging library version
	function setReceiveVersion(uint16 _version) external;

	// @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
	// @param _srcChainId - the chainId of the source chain
	// @param _srcAddress - the contract address of the source contract at the source chain
	function forceResumeReceive(
		uint16 _srcChainId,
		bytes calldata _srcAddress
	) external;
}

// File: src/main/interfaces/layerzero/ILayerZeroEndpoint.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ILayerZeroUserApplicationConfig.sol";

interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
	// @notice send a LayerZero message to the specified address at a LayerZero endpoint.
	// @param _dstChainId - the destination chain identifier
	// @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
	// @param _payload - a custom bytes payload to send to the destination contract
	// @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
	// @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
	// @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
	function send(
		uint16 _dstChainId,
		bytes calldata _destination,
		bytes calldata _payload,
		address payable _refundAddress,
		address _zroPaymentAddress,
		bytes calldata _adapterParams
	) external payable;

	// @notice used by the messaging library to publish verified payload
	// @param _srcChainId - the source chain identifier
	// @param _srcAddress - the source contract (as bytes) at the source chain
	// @param _dstAddress - the address on destination chain
	// @param _nonce - the unbound message ordering nonce
	// @param _gasLimit - the gas limit for external contract execution
	// @param _payload - verified payload to send to the destination contract
	function receivePayload(
		uint16 _srcChainId,
		bytes calldata _srcAddress,
		address _dstAddress,
		uint64 _nonce,
		uint256 _gasLimit,
		bytes calldata _payload
	) external;

	// @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
	// @param _srcChainId - the source chain identifier
	// @param _srcAddress - the source chain contract address
	function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress)
		external
		view
		returns (uint64);

	// @notice get the outboundNonce from this source chain which, consequently, is always an EVM
	// @param _srcAddress - the source chain contract address
	function getOutboundNonce(uint16 _dstChainId, address _srcAddress)
		external
		view
		returns (uint64);

	// @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
	// @param _dstChainId - the destination chain identifier
	// @param _userApplication - the user app address on this EVM chain
	// @param _payload - the custom message to send over LayerZero
	// @param _payInZRO - if false, user app pays the protocol fee in native token
	// @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
	function estimateFees(
		uint16 _dstChainId,
		address _userApplication,
		bytes calldata _payload,
		bool _payInZRO,
		bytes calldata _adapterParam
	) external view returns (uint256 nativeFee, uint256 zroFee);

	// @notice get this Endpoint's immutable source identifier
	function getChainId() external view returns (uint16);

	// @notice the interface to retry failed message on this Endpoint destination
	// @param _srcChainId - the source chain identifier
	// @param _srcAddress - the source chain contract address
	// @param _payload - the payload to be retried
	function retryPayload(
		uint16 _srcChainId,
		bytes calldata _srcAddress,
		bytes calldata _payload
	) external;

	// @notice query if any STORED payload (message blocking) at the endpoint.
	// @param _srcChainId - the source chain identifier
	// @param _srcAddress - the source chain contract address
	function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress)
		external
		view
		returns (bool);

	// @notice query if the _libraryAddress is valid for sending msgs.
	// @param _userApplication - the user app address on this EVM chain
	function getSendLibraryAddress(address _userApplication)
		external
		view
		returns (address);

	// @notice query if the _libraryAddress is valid for receiving msgs.
	// @param _userApplication - the user app address on this EVM chain
	function getReceiveLibraryAddress(address _userApplication)
		external
		view
		returns (address);

	// @notice query if the non-reentrancy guard for send() is on
	// @return true if the guard is on. false otherwise
	function isSendingPayload() external view returns (bool);

	// @notice query if the non-reentrancy guard for receive() is on
	// @return true if the guard is on. false otherwise
	function isReceivingPayload() external view returns (bool);

	// @notice get the configuration of the LayerZero messaging library of the specified version
	// @param _version - messaging library version
	// @param _chainId - the chainId for the pending config change
	// @param _userApplication - the contract address of the user application
	// @param _configType - type of configuration. every messaging library has its own convention.
	function getConfig(
		uint16 _version,
		uint16 _chainId,
		address _userApplication,
		uint256 _configType
	) external view returns (bytes memory);

	// @notice get the send() LayerZero messaging library version
	// @param _userApplication - the contract address of the user application
	function getSendVersion(address _userApplication)
		external
		view
		returns (uint16);

	// @notice get the lzReceive() LayerZero messaging library version
	// @param _userApplication - the contract address of the user application
	function getReceiveVersion(address _userApplication)
		external
		view
		returns (uint16);
}

// 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/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overridden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);

        _afterTokenTransfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);

        _afterTokenTransfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);

        _afterTokenTransfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721Receiver.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

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



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

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// 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);
    }
}