// File: contracts/CloneNurses.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.5;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";
import "./libraries/CloneNurseEnumerable.sol";
import "./interfaces/IERC1271.sol";
import "./interfaces/ICloneNurses.sol";
import "./interfaces/IERC2981.sol";

contract CloneNurses is
    Ownable,
    ERC721("MaidCoin Clone Nurses", "CNURSES"),
    CloneNurseEnumerable,
    ERC1155Holder,
    IERC2981,
    ICloneNurses
{
    struct NurseType {
        uint256 partCount;
        uint256 destroyReturn;
        uint256 power;
        uint256 lifetime;
    }

    struct Nurse {
        uint256 nurseType;
        uint256 endBlock;
        uint256 lastClaimedBlock;
    }

    INursePart public immutable override nursePart;
    IMaidCoin public immutable override maidCoin;
    ITheMaster public immutable override theMaster;
    uint256 private immutable theMasterStartBlock;

    mapping(uint256 => uint256) public override supportingRoute;
    mapping(address => uint256) public override supportingTo;
    mapping(uint256 => uint256) public override supportedPower;
    mapping(uint256 => uint256) public override totalRewardsFromSupporters;

    NurseType[] public override nurseTypes;
    Nurse[] public override nurses;

    uint256 private royaltyFee = 25; // out of 1000
    address private royaltyReceiver; // MaidCafe

    constructor(
        INursePart _nursePart,
        IMaidCoin _maidCoin,
        ITheMaster _theMaster,
        address _royaltyReceiver
    ) {
        nursePart = _nursePart;
        maidCoin = _maidCoin;
        theMaster = _theMaster;
        royaltyReceiver = _royaltyReceiver;
        theMasterStartBlock = _theMaster.startBlock();
    }

    function _baseURI() internal pure override returns (string memory) {
        return "https://api.maidcoin.org/clonenurses/";
    }

    function totalSupply() public view override(CloneNurseEnumerable, ICloneNurseEnumerable) returns (uint256) {
        return nurses.length;
    }

    function addNurseType(
        uint256[] calldata partCounts,
        uint256[] calldata destroyReturns,
        uint256[] calldata powers,
        uint256[] calldata lifetimes
    ) external onlyOwner returns (uint256[] memory) {
        uint256 startId = nurseTypes.length;
        uint256[] memory nurseType = new uint256[](partCounts.length);
        for (uint256 i = 0; i < partCounts.length; i += 1) {
            require(partCounts[i] > 1, "CloneNurses: Invalid partCount");
            nurseTypes.push(
                NurseType({
                    partCount: partCounts[i],
                    destroyReturn: destroyReturns[i],
                    power: powers[i],
                    lifetime: lifetimes[i]
                })
            );
            nurseType[i] = (startId + i);
        }
        return nurseType;
    }

    function nurseTypeCount() external view override returns (uint256) {
        return nurseTypes.length;
    }

    function assemble(uint256 _nurseType, uint256 _parts) public override {
        NurseType storage nurseType = nurseTypes[_nurseType];
        uint256 _partCount = nurseType.partCount;
        require(_parts >= _partCount, "CloneNurses: Not enough parts");

        nursePart.safeTransferFrom(msg.sender, address(this), _nurseType, _parts, "");
        nursePart.burn(_nurseType, _parts);
        uint256 lifetime = ((nurseType.lifetime * (_parts - 1)) / (_partCount - 1));
        uint256 startblock = block.number > theMasterStartBlock ? block.number : theMasterStartBlock;
        uint256 endBlock = startblock + lifetime;
        uint256 id = totalSupply();
        theMaster.deposit(2, nurseType.power, id);
        nurses.push(Nurse({nurseType: _nurseType, endBlock: endBlock, lastClaimedBlock: startblock}));
        supportingRoute[id] = id;
        emit ChangeSupportingRoute(id, id);
        _mint(msg.sender, id);
        emit ElongateLifetime(id, lifetime, 0, endBlock);
    }

    function assembleWithPermit(
        uint256 nurseType,
        uint256 _parts,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external override {
        nursePart.permit(msg.sender, address(this), deadline, v, r, s);
        assemble(nurseType, _parts);
    }

    function elongateLifetime(uint256[] calldata ids, uint256[] calldata parts) external override {
        require(ids.length == parts.length, "CloneNurses: Invalid parameters");
        claim(ids);
        for (uint256 i = 0; i < ids.length; i += 1) {
            require(parts[i] > 0, "CloneNurses: Invalid amounts of parts");
            Nurse storage nurse = nurses[ids[i]];
            uint256 _nurseType = nurse.nurseType;
            NurseType storage nurseType = nurseTypes[_nurseType];

            nursePart.safeTransferFrom(msg.sender, address(this), _nurseType, parts[i], "");
            nursePart.burn(_nurseType, parts[i]);

            uint256 oldEndBlock = nurse.endBlock;
            uint256 from;
            if (block.number <= oldEndBlock) from = oldEndBlock;
            else from = block.number;

            uint256 rechagedLifetime = ((nurseType.lifetime * parts[i]) / (nurseType.partCount - 1));
            uint256 newEndBlock = from + rechagedLifetime;
            nurse.endBlock = newEndBlock;
            emit ElongateLifetime(ids[i], rechagedLifetime, oldEndBlock, newEndBlock);
        }
    }

    function destroy(uint256[] calldata ids, uint256[] calldata toIds) external override {
        require(ids.length == toIds.length, "CloneNurses: Invalid parameters");
        for (uint256 i = 0; i < ids.length; i += 1) {
            require(msg.sender == ownerOf(ids[i]), "CloneNurses: Forbidden");
            uint256 power = supportedPower[ids[i]];
            if (power == 0) {
                supportingRoute[ids[i]] = type(uint256).max;
                emit ChangeSupportingRoute(ids[i], type(uint256).max);
            } else {
                require(toIds[i] != ids[i], "CloneNurses: Invalid id, toId");
                require(_exists(toIds[i]), "CloneNurses: Invalid toId");

                supportingRoute[ids[i]] = toIds[i];
                emit ChangeSupportingRoute(ids[i], toIds[i]);
                supportedPower[toIds[i]] += power;
                supportedPower[ids[i]] = 0;
                emit ChangeSupportedPower(toIds[i], int256(power));
            }
            NurseType storage nurseType = nurseTypes[nurses[ids[i]].nurseType];

            uint256 balanceBefore = maidCoin.balanceOf(address(this));
            theMaster.withdraw(2, nurseType.power, ids[i]);
            uint256 balanceAfter = maidCoin.balanceOf(address(this));
            uint256 reward = balanceAfter - balanceBefore;
            _claim(ids[i], reward);

            theMaster.mint(msg.sender, nurseType.destroyReturn);
            _burn(ids[i]);
            delete nurses[ids[i]];
        }
    }

    function claim(uint256[] calldata ids) public override {
        for (uint256 i = 0; i < ids.length; i += 1) {
            require(msg.sender == ownerOf(ids[i]), "CloneNurses: Forbidden");
            uint256 balanceBefore = maidCoin.balanceOf(address(this));
            theMaster.deposit(2, 0, ids[i]);
            uint256 balanceAfter = maidCoin.balanceOf(address(this));
            uint256 reward = balanceAfter - balanceBefore;
            _claim(ids[i], reward);
        }
    }

    function _claim(uint256 id, uint256 reward) internal {
        if (reward == 0) return;
        else {
            Nurse storage nurse = nurses[id];
            uint256 endBlock = nurse.endBlock;
            uint256 lastClaimedBlock = nurse.lastClaimedBlock;
            uint256 burningReward;
            uint256 claimableReward;
            if (endBlock <= lastClaimedBlock) burningReward = reward;
            else if (endBlock < block.number) {
                claimableReward = (reward * (endBlock - lastClaimedBlock)) / (block.number - lastClaimedBlock);
                burningReward = reward - claimableReward;
            } else claimableReward = reward;

            if (burningReward > 0) maidCoin.burn(burningReward);
            if (claimableReward > 0) maidCoin.transfer(msg.sender, claimableReward);
            nurse.lastClaimedBlock = block.number;
            emit Claim(id, msg.sender, claimableReward);
        }
    }

    function pendingReward(uint256 id) external view override returns (uint256 claimableReward) {
        require(_exists(id), "CloneNurses: Invalid id");
        uint256 reward = theMaster.pendingReward(2, id);

        if (reward == 0) return 0;
        else {
            Nurse storage nurse = nurses[id];
            uint256 endBlock = nurse.endBlock;
            uint256 lastClaimedBlock = nurse.lastClaimedBlock;
            if (endBlock <= lastClaimedBlock) return 0;
            else if (endBlock < block.number) {
                claimableReward = (reward * (endBlock - lastClaimedBlock)) / (block.number - lastClaimedBlock);
            } else claimableReward = reward;
        }
    }

    function setSupportingTo(
        address supporter,
        uint256 to,
        uint256 amounts
    ) public override {
        require(msg.sender == address(theMaster), "CloneNurses: Forbidden");
        require(_exists(to), "CloneNurses: Invalid target");
        supportingTo[supporter] = to;
        emit SupportTo(supporter, to);

        if (amounts > 0) {
            supportedPower[to] += amounts;
            emit ChangeSupportedPower(to, int256(amounts));
        }
    }

    function findSupportingTo(address supporter) external view override returns (address, uint256) {
        uint256 _supportingTo = supportingTo[supporter];
        uint256 _route = supportingRoute[_supportingTo];
        if (_route == _supportingTo) return (ownerOf(_supportingTo), _supportingTo);
        while (_route != _supportingTo) {
            _supportingTo = _route;
            _route = supportingRoute[_supportingTo];
        }
        return (ownerOf(_supportingTo), _supportingTo);
    }

    function checkSupportingRoute(address supporter) public override returns (address, uint256) {
        uint256 _supportingTo = supportingTo[supporter];
        uint256 _route = supportingRoute[_supportingTo];
        if (_route == _supportingTo) return (ownerOf(_supportingTo), _supportingTo);
        uint256 initialSupportTo = _supportingTo;
        while (_route != _supportingTo) {
            _supportingTo = _route;
            _route = supportingRoute[_supportingTo];
        }
        supportingTo[supporter] = _supportingTo;
        supportingRoute[initialSupportTo] = _supportingTo;
        emit ChangeSupportingRoute(initialSupportTo, _supportingTo);
        emit SupportTo(supporter, _supportingTo);
        return (ownerOf(_supportingTo), _supportingTo);
    }

    function changeSupportedPower(address supporter, int256 power) public override {
        require(msg.sender == address(theMaster), "CloneNurses: Forbidden");
        (, uint256 id) = checkSupportingRoute(supporter);
        int256 _supportedPower = int256(supportedPower[id]);
        if (power < 0) require(_supportedPower >= (-power), "CloneNurses: Outranged power");
        _supportedPower += power;
        supportedPower[id] = uint256(_supportedPower);
        emit ChangeSupportedPower(id, power);
    }

    function recordRewardsTransfer(
        address supporter,
        uint256 id,
        uint256 amounts
    ) internal {
        totalRewardsFromSupporters[id] += amounts;
        emit TransferSupportingRewards(supporter, id, amounts);
    }

    function shareRewards(
        uint256 pending,
        address supporter,
        uint8 supportingRatio
    ) public override returns (address nurseOwner, uint256 amountToNurseOwner) {
        require(msg.sender == address(theMaster), "CloneNurses: Forbidden");
        amountToNurseOwner = (pending * supportingRatio) / 100;
        uint256 _supportTo;
        if (amountToNurseOwner > 0) {
            (nurseOwner, _supportTo) = checkSupportingRoute(supporter);
            recordRewardsTransfer(supporter, _supportTo, amountToNurseOwner);
        }
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal override(ERC721, CloneNurseEnumerable) {
        super._beforeTokenTransfer(from, to, tokenId);
    }

    function supportsInterface(bytes4 interfaceId)
        public
        view
        override(ERC721, ERC1155Receiver, IERC165)
        returns (bool)
    {
        return interfaceId == 0x2a55205a || super.supportsInterface(interfaceId);
    }

    function royaltyInfo(uint256, uint256 _salePrice) external view override returns (address, uint256) {
        return (royaltyReceiver, (_salePrice * royaltyFee) / 1000);
    }

    function setRoyaltyInfo(address _receiver, uint256 _royaltyFee) external onlyOwner {
        royaltyReceiver = _receiver;
        royaltyFee = _royaltyFee;
    }
    
    function exists(uint256 id) external view override returns (bool) {
        return _exists(id);
    }
}

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



// SPDX-License-Identifier: MIT

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 () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), 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 {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./ERC1155Receiver.sol";

/**
 * @dev _Available since v3.1._
 */
contract ERC1155Holder is ERC1155Receiver {
    function onERC1155Received(address, address, uint256, uint256, bytes memory) public virtual override returns (bytes4) {
        return this.onERC1155Received.selector;
    }

    function onERC1155BatchReceived(address, address, uint256[] memory, uint256[] memory, bytes memory) public virtual override returns (bytes4) {
        return this.onERC1155BatchReceived.selector;
    }
}

// File: contracts/libraries/CloneNurseEnumerable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./ERC721.sol";
import "../interfaces/ICloneNurseEnumerable.sol";

/**
 * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
 * enumerability of all the token ids in the contract as well as all token ids owned by each
 * account.

 * @dev MaidCoin: This is for CloneNurses and the like minted in order from 0 and have burn function.
 * This doesn't have tokenByIndex function.
 */
abstract contract CloneNurseEnumerable is ERC721, ICloneNurseEnumerable {
    // Mapping from owner to list of owned token IDs
    mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

    // Mapping from token ID to index of the owner tokens list
    mapping(uint256 => uint256) private _ownedTokensIndex;

    /**
     * @dev See {ICloneNurseEnumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        require(index < ERC721.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
        return _ownedTokens[owner][index];
    }

    /**
     * @dev See {ICloneNurseEnumerable-totalSupply}.
     */
    //TODO
    function totalSupply() public view virtual override returns (uint256) {
        // return _allTokens.length;
    }

    /**
     * @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` cannot be the zero address.
     * - `to` cannot be the zero address.
     *
     * 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 override {
        super._beforeTokenTransfer(from, to, tokenId);

        if (from == address(0)) {
            _addTokenToOwnerEnumeration(to, tokenId);
        } else if (to == address(0)) {
            _removeTokenFromOwnerEnumeration(from, tokenId);
        } else {
            _removeTokenFromOwnerEnumeration(from, tokenId);
            _addTokenToOwnerEnumeration(to, tokenId);
        }
    }

    /**
     * @dev Private function to add a token to this extension's ownership-tracking data structures.
     * @param to address representing the new owner of the given token ID
     * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
     */
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        uint256 length = ERC721.balanceOf(to);
        _ownedTokens[to][length] = tokenId;
        _ownedTokensIndex[tokenId] = length;
    }

    /**
     * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
     * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
     * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
     * This has O(1) time complexity, but alters the order of the _ownedTokens array.
     * @param from address representing the previous owner of the given token ID
     * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
     */
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
        // then delete the last slot (swap and pop).

        uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        // When the token to delete is the last token, the swap operation is unnecessary
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
        }

        // This also deletes the contents at the last position of the array
        delete _ownedTokensIndex[tokenId];
        delete _ownedTokens[from][lastTokenIndex];
    }
}

// File: contracts/interfaces/IERC1271.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

/// @title Interface for verifying contract-based account signatures
/// @notice Interface that verifies provided signature for the data
/// @dev Interface defined by EIP-1271
interface IERC1271 {
    /// @notice Returns whether the provided signature is valid for the provided data
    /// @dev MUST return the bytes4 magic value 0x1626ba7e when function passes.
    /// MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5).
    /// MUST allow external calls.
    /// @param hash Hash of the data to be signed
    /// @param signature Signature byte array associated with _data
    /// @return magicValue The bytes4 magic value 0x1626ba7e
    function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
}

// File: contracts/interfaces/ICloneNurses.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "./ICloneNurseEnumerable.sol";
import "./ISupportable.sol";
import "./INursePart.sol";
import "./IMaidCoin.sol";
import "./ITheMaster.sol";

interface ICloneNurses is IERC721, IERC721Metadata, ICloneNurseEnumerable, ISupportable {
    event Claim(uint256 indexed id, address indexed claimer, uint256 reward);
    event ElongateLifetime(uint256 indexed id, uint256 rechargedLifetime, uint256 lastEndBlock, uint256 newEndBlock);

    function nursePart() external view returns (INursePart);

    function maidCoin() external view returns (IMaidCoin);

    function theMaster() external view returns (ITheMaster);

    function nurseTypes(uint256 typeId)
        external
        view
        returns (
            uint256 partCount,
            uint256 destroyReturn,
            uint256 power,
            uint256 lifetime
        );

    function nurseTypeCount() external view returns (uint256);

    function nurses(uint256 id)
        external
        view
        returns (
            uint256 nurseType,
            uint256 endBlock,
            uint256 lastClaimedBlock
        );

    function assemble(uint256 nurseType, uint256 parts) external;

    function assembleWithPermit(
        uint256 nurseType,
        uint256 parts,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function elongateLifetime(uint256[] calldata ids, uint256[] calldata parts) external;

    function destroy(uint256[] calldata ids, uint256[] calldata toIds) external;

    function claim(uint256[] calldata ids) external;

    function pendingReward(uint256 id) external view returns (uint256);

    function findSupportingTo(address supporter) external view returns (address, uint256);

    function exists(uint256 id) external view returns (bool);
}

// File: contracts/interfaces/IERC2981.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.5;

import "@openzeppelin/contracts/utils/introspection/IERC165.sol";

///
/// @dev Interface for the NFT Royalty Standard
///
interface IERC2981 is IERC165 {
    /// ERC165 bytes to add to interface array - set in parent contract
    /// implementing this standard
    ///
    /// bytes4(keccak256("royaltyInfo(uint256,uint256)")) == 0x2a55205a
    /// bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
    /// _registerInterface(_INTERFACE_ID_ERC2981);

    /// @notice Called with the sale price to determine how much royalty
    //          is owed and to whom.
    /// @param _tokenId - the NFT asset queried for royalty information
    /// @param _salePrice - the sale price of the NFT asset specified by _tokenId
    /// @return receiver - address of who should be sent the royalty payment
    /// @return royaltyAmount - the royalty payment amount for _salePrice
    function royaltyInfo(uint256 _tokenId, uint256 _salePrice)
        external
        view
        returns (address receiver, uint256 royaltyAmount);
}

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



// SPDX-License-Identifier: MIT

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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/token/ERC1155/utils/ERC1155Receiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC1155Receiver.sol";
import "../../../utils/introspection/ERC165.sol";

/**
 * @dev _Available since v3.1._
 */
abstract contract ERC1155Receiver is ERC165, IERC1155Receiver {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return interfaceId == type(IERC1155Receiver).interfaceId
            || super.supportsInterface(interfaceId);
    }
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155Receiver.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

/**
 * @dev _Available since v3.1._
 */
interface IERC1155Receiver is IERC165 {

    /**
        @dev Handles the receipt of a single ERC1155 token type. This function is
        called at the end of a `safeTransferFrom` after the balance has been updated.
        To accept the transfer, this must return
        `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
        (i.e. 0xf23a6e61, or its own function selector).
        @param operator The address which initiated the transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param id The ID of the token being transferred
        @param value The amount of tokens being transferred
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
    */
    function onERC1155Received(
        address operator,
        address from,
        uint256 id,
        uint256 value,
        bytes calldata data
    )
        external
        returns(bytes4);

    /**
        @dev Handles the receipt of a multiple ERC1155 token types. This function
        is called at the end of a `safeBatchTransferFrom` after the balances have
        been updated. To accept the transfer(s), this must return
        `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
        (i.e. 0xbc197c81, or its own function selector).
        @param operator The address which initiated the batch transfer (i.e. msg.sender)
        @param from The address which previously owned the token
        @param ids An array containing ids of each token being transferred (order and length must match values array)
        @param values An array containing amounts of each token being transferred (order and length must match ids array)
        @param data Additional data with no specified format
        @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
    */
    function onERC1155BatchReceived(
        address operator,
        address from,
        uint256[] calldata ids,
        uint256[] calldata values,
        bytes calldata data
    )
        external
        returns(bytes4);
}

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



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: contracts/libraries/ERC721.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/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 overriden 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];
    }

    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal {
        require(owner != operator, "ERC721: approve to caller");

        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @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 || getApproved(tokenId) == spender || isApprovedForAll(owner, 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);
    }

    /**
     * @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);
    }

    /**
     * @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 of token that is not own");
        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);
    }

    /**
     * @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 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(to).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 {}
}

// File: contracts/interfaces/ICloneNurseEnumerable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface ICloneNurseEnumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
}

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



// SPDX-License-Identifier: MIT

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

    /**
     * @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 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);

    /**
      * @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;
}

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



// SPDX-License-Identifier: MIT

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 `IERC721.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

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

pragma solidity ^0.8.0;

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 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");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (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");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private 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

                // solhint-disable-next-line no-inline-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

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant alphabet = "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] = alphabet[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

}

// File: contracts/interfaces/ISupportable.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

interface ISupportable {
    event SupportTo(address indexed supporter, uint256 indexed to);
    event ChangeSupportingRoute(uint256 indexed from, uint256 indexed to);
    event ChangeSupportedPower(uint256 indexed id, int256 power);
    event TransferSupportingRewards(address indexed supporter, uint256 indexed id, uint256 amounts);

    function supportingRoute(uint256 id) external view returns (uint256);

    function supportingTo(address supporter) external view returns (uint256);

    function supportedPower(uint256 id) external view returns (uint256);

    function totalRewardsFromSupporters(uint256 id) external view returns (uint256);

    function setSupportingTo(
        address supporter,
        uint256 to,
        uint256 amounts
    ) external;

    function checkSupportingRoute(address supporter) external returns (address, uint256);

    function changeSupportedPower(address supporter, int256 power) external;

    function shareRewards(
        uint256 pending,
        address supporter,
        uint8 supportingRatio
    ) external returns (address nurseOwner, uint256 amountToNurseOwner);
}

// File: contracts/interfaces/INursePart.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";

interface INursePart is IERC1155 {
    function DOMAIN_SEPARATOR() external view returns (bytes32);

    function PERMIT_TYPEHASH() external view returns (bytes32);

    function nonces(address owner) external view returns (uint256);

    function mint(
        address to,
        uint256 id,
        uint256 amount
    ) external;

    function burn(uint256 id, uint256 amount) external;

    function permit(
        address owner,
        address spender,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
}

// File: contracts/interfaces/IMaidCoin.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

interface IMaidCoin {
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

    function name() external pure returns (string memory);

    function symbol() external pure returns (string memory);

    function decimals() external pure returns (uint8);

    function totalSupply() external view returns (uint256);

    function INITIAL_SUPPLY() external pure returns (uint256);

    function balanceOf(address owner) external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 value) external returns (bool);

    function transfer(address to, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);

    function PERMIT_TYPEHASH() external pure returns (bytes32);

    function nonces(address owner) external view returns (uint256);

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function mint(address to, uint256 amount) external;

    function burn(uint256 amount) external;
}

// File: contracts/interfaces/ITheMaster.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

import "./IMaidCoin.sol";
import "./IRewardCalculator.sol";
import "./ISupportable.sol";
import "./IMasterChefModule.sol";

interface ITheMaster is IMasterChefModule {
    event ChangeRewardCalculator(address addr);

    event Add(
        uint256 indexed pid,
        address addr,
        bool indexed delegate,
        bool indexed mintable,
        address supportable,
        uint8 supportingRatio,
        uint256 allocPoint
    );

    event Set(uint256 indexed pid, uint256 allocPoint);
    event Deposit(uint256 indexed userId, uint256 indexed pid, uint256 amount);
    event Withdraw(uint256 indexed userId, uint256 indexed pid, uint256 amount);
    event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);

    event Support(address indexed supporter, uint256 indexed pid, uint256 amount);
    event Desupport(address indexed supporter, uint256 indexed pid, uint256 amount);
    event EmergencyDesupport(address indexed user, uint256 indexed pid, uint256 amount);

    event SetIsSupporterPool(uint256 indexed pid, bool indexed status);

    function initialRewardPerBlock() external view returns (uint256);

    function decreasingInterval() external view returns (uint256);

    function startBlock() external view returns (uint256);

    function maidCoin() external view returns (IMaidCoin);

    function rewardCalculator() external view returns (IRewardCalculator);

    function poolInfo(uint256 pid)
        external
        view
        returns (
            address addr,
            bool delegate,
            ISupportable supportable,
            uint8 supportingRatio,
            uint256 allocPoint,
            uint256 lastRewardBlock,
            uint256 accRewardPerShare,
            uint256 supply
        );

    function poolCount() external view returns (uint256);

    function userInfo(uint256 pid, uint256 user) external view returns (uint256 amount, uint256 rewardDebt);

    function mintableByAddr(address addr) external view returns (bool);

    function totalAllocPoint() external view returns (uint256);

    function pendingReward(uint256 pid, uint256 userId) external view returns (uint256);

    function rewardPerBlock() external view returns (uint256);

    function changeRewardCalculator(address addr) external;

    function add(
        address addr,
        bool delegate,
        bool mintable,
        address supportable,
        uint8 supportingRatio,
        uint256 allocPoint
    ) external;

    function set(uint256[] calldata pid, uint256[] calldata allocPoint) external;

    function deposit(
        uint256 pid,
        uint256 amount,
        uint256 userId
    ) external;

    function depositWithPermit(
        uint256 pid,
        uint256 amount,
        uint256 userId,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function depositWithPermitMax(
        uint256 pid,
        uint256 amount,
        uint256 userId,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function withdraw(
        uint256 pid,
        uint256 amount,
        uint256 userId
    ) external;

    function emergencyWithdraw(uint256 pid) external;

    function support(
        uint256 pid,
        uint256 amount,
        uint256 supportTo
    ) external;

    function supportWithPermit(
        uint256 pid,
        uint256 amount,
        uint256 supportTo,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function supportWithPermitMax(
        uint256 pid,
        uint256 amount,
        uint256 supportTo,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    function desupport(uint256 pid, uint256 amount) external;

    function emergencyDesupport(uint256 pid) external;

    function mint(address to, uint256 amount) external;

    function claimSushiReward(uint256 id) external;

    function pendingSushiReward(uint256 id) external view returns (uint256);
}

// File: @openzeppelin/contracts/token/ERC1155/IERC1155.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

/**
 * @dev Required interface of an ERC1155 compliant contract, as defined in the
 * https://eips.ethereum.org/EIPS/eip-1155[EIP].
 *
 * _Available since v3.1._
 */
interface IERC1155 is IERC165 {
    /**
     * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
     */
    event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);

    /**
     * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
     * transfers.
     */
    event TransferBatch(address indexed operator, address indexed from, address indexed to, uint256[] ids, uint256[] values);

    /**
     * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
     * `approved`.
     */
    event ApprovalForAll(address indexed account, address indexed operator, bool approved);

    /**
     * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
     *
     * If an {URI} event was emitted for `id`, the standard
     * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
     * returned by {IERC1155MetadataURI-uri}.
     */
    event URI(string value, uint256 indexed id);

    /**
     * @dev Returns the amount of tokens of token type `id` owned by `account`.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function balanceOf(address account, uint256 id) external view returns (uint256);

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
     *
     * Requirements:
     *
     * - `accounts` and `ids` must have the same length.
     */
    function balanceOfBatch(address[] calldata accounts, uint256[] calldata ids) external view returns (uint256[] memory);

    /**
     * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
     *
     * Emits an {ApprovalForAll} event.
     *
     * Requirements:
     *
     * - `operator` cannot be the caller.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
     *
     * See {setApprovalForAll}.
     */
    function isApprovedForAll(address account, address operator) external view returns (bool);

    /**
     * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
     *
     * Emits a {TransferSingle} event.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
     * - `from` must have a balance of tokens of type `id` of at least `amount`.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
     * acceptance magic value.
     */
    function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external;

    /**
     * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
     *
     * Emits a {TransferBatch} event.
     *
     * Requirements:
     *
     * - `ids` and `amounts` must have the same length.
     * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
     * acceptance magic value.
     */
    function safeBatchTransferFrom(address from, address to, uint256[] calldata ids, uint256[] calldata amounts, bytes calldata data) external;
}

// File: contracts/interfaces/IRewardCalculator.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

interface IRewardCalculator {
    function rewardPerBlock() external view returns (uint256);
}

// File: contracts/interfaces/IMasterChefModule.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

import "./IMasterChef.sol";
import "../uniswapv2/interfaces/IUniswapV2Pair.sol";

interface IMasterChefModule {
    function lpToken() external view returns (IUniswapV2Pair);

    function sushi() external view returns (IERC20);

    function sushiMasterChef() external view returns (IMasterChef);

    function masterChefPid() external view returns (uint256);

    function sushiLastRewardBlock() external view returns (uint256);

    function accSushiPerShare() external view returns (uint256);
}

// File: contracts/interfaces/IMasterChef.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
pragma experimental ABIEncoderV2;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IMasterChef {
    struct UserInfo {
        uint256 amount; // How many LP tokens the user has provided.
        uint256 rewardDebt; // Reward debt. See explanation below.
    }

    struct PoolInfo {
        IERC20 lpToken; // Address of LP token contract.
        uint256 allocPoint; // How many allocation points assigned to this pool. SUSHI to distribute per block.
        uint256 lastRewardBlock; // Last block number that SUSHI distribution occurs.
        uint256 accSushiPerShare; // Accumulated SUSHI per share, times 1e12. See below.
    }

    function poolInfo(uint256 pid) external view returns (IMasterChef.PoolInfo memory);

    function userInfo(uint256 pid, address user) external view returns (IMasterChef.UserInfo memory);

    function pendingSushi(uint256 _pid, address _user) external view returns (uint256);

    function deposit(uint256 _pid, uint256 _amount) external;

    function withdraw(uint256 _pid, uint256 _amount) external;
}

// File: contracts/uniswapv2/interfaces/IUniswapV2Pair.sol



// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

    function name() external pure returns (string memory);

    function symbol() external pure returns (string memory);

    function decimals() external pure returns (uint8);

    function totalSupply() external view returns (uint256);

    function balanceOf(address owner) external view returns (uint256);

    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 value) external returns (bool);

    function transfer(address to, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);

    function PERMIT_TYPEHASH() external pure returns (bytes32);

    function nonces(address owner) external view returns (uint256);

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    event Mint(address indexed sender, uint256 amount0, uint256 amount1);
    event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint256 amount0In,
        uint256 amount1In,
        uint256 amount0Out,
        uint256 amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint256);

    function factory() external view returns (address);

    function token0() external view returns (address);

    function token1() external view returns (address);

    function getReserves()
        external
        view
        returns (
            uint112 reserve0,
            uint112 reserve1,
            uint32 blockTimestampLast
        );

    function price0CumulativeLast() external view returns (uint256);

    function price1CumulativeLast() external view returns (uint256);

    function kLast() external view returns (uint256);

    function mint(address to) external returns (uint256 liquidity);

    function burn(address to) external returns (uint256 amount0, uint256 amount1);

    function swap(
        uint256 amount0Out,
        uint256 amount1Out,
        address to,
        bytes calldata data
    ) external;

    function skim(address to) external;

    function sync() external;

    function initialize(address, address) external;
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

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);
}