// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-upgradeable-0.7.2/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/utils/ReentrancyGuardUpgradeable.sol";
import "@openzeppelin/contracts-0.7.2/token/ERC721/IERC721.sol";
import "./storage/SuperRareBazaarStorage.sol";
import "./ISuperRareBazaar.sol";
/// @author koloz
/// @title SuperRareBazaar
/// @notice The unified contract for the bazaar logic (Marketplace and Auction House).
/// @dev All storage is inherrited and append only (no modifications) to make upgrade compliant.
contract SuperRareBazaar is
    ISuperRareBazaar,
    OwnableUpgradeable,
    ReentrancyGuardUpgradeable,
    SuperRareBazaarStorage
{
    /////////////////////////////////////////////////////////////////////////
    // Initializer
    /////////////////////////////////////////////////////////////////////////
    function initialize(
        address _marketplaceSettings,
        address _royaltyRegistry,
        address _royaltyEngine,
        address _superRareMarketplace,
        address _superRareAuctionHouse,
        address _spaceOperatorRegistry,
        address _approvedTokenRegistry,
        address _payments,
        address _stakingRegistry,
        address _networkBeneficiary
    ) public initializer {
        require(_marketplaceSettings != address(0));
        require(_royaltyRegistry != address(0));
        require(_royaltyEngine != address(0));
        require(_superRareMarketplace != address(0));
        require(_superRareAuctionHouse != address(0));
        require(_spaceOperatorRegistry != address(0));
        require(_approvedTokenRegistry != address(0));
        require(_payments != address(0));
        require(_networkBeneficiary != address(0));
        marketplaceSettings = IMarketplaceSettings(_marketplaceSettings);
        royaltyRegistry = IERC721CreatorRoyalty(_royaltyRegistry);
        royaltyEngine = IRoyaltyEngineV1(_royaltyEngine);
        superRareMarketplace = _superRareMarketplace;
        superRareAuctionHouse = _superRareAuctionHouse;
        spaceOperatorRegistry = ISpaceOperatorRegistry(_spaceOperatorRegistry);
        approvedTokenRegistry = IApprovedTokenRegistry(_approvedTokenRegistry);
        payments = IPayments(_payments);
        stakingRegistry = _stakingRegistry;
        networkBeneficiary = _networkBeneficiary;
        minimumBidIncreasePercentage = 10;
        maxAuctionLength = 7 days;
        auctionLengthExtension = 15 minutes;
        offerCancelationDelay = 5 minutes;
        __Ownable_init();
        __ReentrancyGuard_init();
    }
    /////////////////////////////////////////////////////////////////////////
    // Admin Functions
    /////////////////////////////////////////////////////////////////////////
    function setMarketplaceSettings(address _marketplaceSettings)
        external
        onlyOwner
    {
        require(_marketplaceSettings != address(0));
        marketplaceSettings = IMarketplaceSettings(_marketplaceSettings);
    }
    function setRoyaltyRegistry(address _royaltyRegistry) external onlyOwner {
        require(_royaltyRegistry != address(0));
        royaltyRegistry = IERC721CreatorRoyalty(_royaltyRegistry);
    }
    function setRoyaltyEngine(address _royaltyEngine) external onlyOwner {
        require(_royaltyEngine != address(0));
        royaltyEngine = IRoyaltyEngineV1(_royaltyEngine);
    }
    function setSuperRareMarketplace(address _superRareMarketplace)
        external
        onlyOwner
    {
        require(_superRareMarketplace != address(0));
        superRareMarketplace = _superRareMarketplace;
    }
    function setSuperRareAuctionHouse(address _superRareAuctionHouse)
        external
        onlyOwner
    {
        require(_superRareAuctionHouse != address(0));
        superRareAuctionHouse = _superRareAuctionHouse;
    }
    function setSpaceOperatorRegistry(address _spaceOperatorRegistry)
        external
        onlyOwner
    {
        require(_spaceOperatorRegistry != address(0));
        spaceOperatorRegistry = ISpaceOperatorRegistry(_spaceOperatorRegistry);
    }
    function setApprovedTokenRegistry(address _approvedTokenRegistry)
        external
        onlyOwner
    {
        require(_approvedTokenRegistry != address(0));
        approvedTokenRegistry = IApprovedTokenRegistry(_approvedTokenRegistry);
    }
    function setPayments(address _payments) external onlyOwner {
        require(_payments != address(0));
        payments = IPayments(_payments);
    }
    function setStakingRegistry(address _stakingRegistry) external onlyOwner {
        require(_stakingRegistry != address(0));
        stakingRegistry = _stakingRegistry;
    }
    function setNetworkBeneficiary(address _networkBeneficiary)
        external
        onlyOwner
    {
        require(_networkBeneficiary != address(0));
        networkBeneficiary = _networkBeneficiary;
    }
    function setMinimumBidIncreasePercentage(
        uint8 _minimumBidIncreasePercentage
    ) external onlyOwner {
        minimumBidIncreasePercentage = _minimumBidIncreasePercentage;
    }
    function setMaxAuctionLength(uint8 _maxAuctionLength) external onlyOwner {
        maxAuctionLength = _maxAuctionLength;
    }
    function setAuctionLengthExtension(uint256 _auctionLengthExtension)
        external
        onlyOwner
    {
        auctionLengthExtension = _auctionLengthExtension;
    }
    function setOfferCancelationDelay(uint256 _offerCancelationDelay)
        external
        onlyOwner
    {
        offerCancelationDelay = _offerCancelationDelay;
    }
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Functions
    /////////////////////////////////////////////////////////////////////////
    /// @notice Place an offer for a given asset
    /// @dev Notice we need to verify that the msg sender has approved us to move funds on their behalf.
    /// @dev Covers use of any currency (0 address is eth).
    /// @dev _amount is the amount of the offer excluding the marketplace fee.
    /// @dev There can be multiple offers of different currencies, but only 1 per currency.
    /// @param _originContract Contract address of the asset being listed.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the token being offered.
    /// @param _amount Amount being offered.
    /// @param _convertible If the offer can be converted into an auction
    function offer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        bool _convertible
    ) external payable override {
        (bool success, bytes memory data) = superRareMarketplace.delegatecall(
            abi.encodeWithSelector(
                this.offer.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _amount,
                _convertible
            )
        );
        require(success, string(data));
    }
    /// @notice Purchases the token for the current sale price.
    /// @dev Covers use of any currency (0 address is eth).
    /// @dev Need to verify that the buyer (if not using eth) has the marketplace approved for _currencyContract.
    /// @dev Need to verify that the seller has the marketplace approved for _originContract.
    /// @param _originContract Contract address for asset being bought.
    /// @param _tokenId TokenId of asset being bought.
    /// @param _currencyAddress Currency address of asset being used to buy.
    /// @param _amount Amount the piece if being bought for (including marketplace fee).
    function buy(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable override {
        (bool success, bytes memory data) = superRareMarketplace.delegatecall(
            abi.encodeWithSelector(
                this.buy.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _amount
            )
        );
        require(success, string(data));
    }
    /// @notice Cancels an existing offer the sender has placed on a piece.
    /// @param _originContract Contract address of token.
    /// @param _tokenId TokenId that has an offer.
    /// @param _currencyAddress Currency address of the offer.
    function cancelOffer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress
    ) external override {
        (bool success, bytes memory data) = superRareMarketplace.delegatecall(
            abi.encodeWithSelector(
                this.cancelOffer.selector,
                _originContract,
                _tokenId,
                _currencyAddress
            )
        );
        require(success, string(data));
    }
    /// @notice Sets a sale price for the given asset(s) directed at the _target address.
    /// @dev Covers use of any currency (0 address is eth).
    /// @dev Sale price for everyone is denoted as the 0 address.
    /// @dev Only 1 currency can be used for the sale price directed at a speicific target.
    /// @dev _listPrice of 0 signifies removing the list price for the provided currency.
    /// @dev This function can be used for counter offers as well.
    /// @param _originContract Contract address of the asset being listed.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Contract address of the currency asset is being listed for.
    /// @param _listPrice Amount of the currency the asset is being listed for (including all decimal points).
    /// @param _target Address of the person this sale price is target to.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function setSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _listPrice,
        address _target,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        (bool success, bytes memory data) = superRareMarketplace.delegatecall(
            abi.encodeWithSelector(
                this.setSalePrice.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _listPrice,
                _target,
                _splitAddresses,
                _splitRatios
            )
        );
        require(success, string(data));
    }
    /// @notice Removes the current sale price of an asset for _target for the given currency.
    /// @dev Sale prices could still exist for different currencies.
    /// @dev Sale prices could still exist for different targets.
    /// @dev Zero address for _currency means that its listed in ether.
    /// @dev _target of zero address is the general sale price.
    /// @param _originContract The origin contract of the asset.
    /// @param _tokenId The tokenId of the asset within the _originContract.
    /// @param _target The address of the person
    function removeSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _target
    ) external override {
        IERC721 erc721 = IERC721(_originContract);
        address tokenOwner = erc721.ownerOf(_tokenId);
        require(
            msg.sender == tokenOwner,
            "removeSalePrice::Must be tokenOwner."
        );
        delete tokenSalePrices[_originContract][_tokenId][_target];
        emit SetSalePrice(
            _originContract,
            address(0),
            address(0),
            0,
            _tokenId,
            new address payable[](0),
            new uint8[](0)
        );
    }
    /// @notice Accept an offer placed on _originContract : _tokenId.
    /// @dev Zero address for _currency means that the offer being accepted is in ether.
    /// @param _originContract Contract of the asset the offer was made on.
    /// @param _tokenId TokenId of the asset.
    /// @param _currencyAddress Address of the currency used for the offer.
    /// @param _amount Amount the offer was for/and is being accepted.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function acceptOffer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        (bool success, bytes memory data) = superRareMarketplace.delegatecall(
            abi.encodeWithSelector(
                this.acceptOffer.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _amount,
                _splitAddresses,
                _splitRatios
            )
        );
        require(success, string(data));
    }
    /////////////////////////////////////////////////////////////////////////
    // Auction House Functions
    /////////////////////////////////////////////////////////////////////////
    /// @notice Configures an Auction for a given asset.
    /// @dev If auction type is coldie (reserve) then _startingAmount cant be 0.
    /// @dev _currencyAddress equal to the zero address denotes eth.
    /// @dev All time related params are unix epoch timestamps.
    /// @param _auctionType The type of auction being configured.
    /// @param _originContract Contract address of the asset being put up for auction.
    /// @param _tokenId Token Id of the asset.
    /// @param _startingAmount The reserve price or min bid of an auction.
    /// @param _currencyAddress The currency the auction is being conducted in.
    /// @param _lengthOfAuction The amount of time in seconds that the auction is configured for.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function configureAuction(
        bytes32 _auctionType,
        address _originContract,
        uint256 _tokenId,
        uint256 _startingAmount,
        address _currencyAddress,
        uint256 _lengthOfAuction,
        uint256 _startTime,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        (bool success, bytes memory data) = superRareAuctionHouse.delegatecall(
            abi.encodeWithSelector(
                this.configureAuction.selector,
                _auctionType,
                _originContract,
                _tokenId,
                _startingAmount,
                _currencyAddress,
                _lengthOfAuction,
                _startTime,
                _splitAddresses,
                _splitRatios
            )
        );
        require(success, string(data));
    }
    /// @notice Converts an offer into a coldie auction.
    /// @dev Covers use of any currency (0 address is eth).
    /// @dev Only covers converting an offer to a coldie auction.
    /// @dev Cant convert offer if an auction currently exists.
    /// @param _originContract Contract address of the asset.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the currency being converted.
    /// @param _amount Amount being converted into an auction.
    /// @param _lengthOfAuction Number of seconds the auction will last.
    /// @param _splitAddresses Addresses that the sellers take in will be split amongst.
    /// @param _splitRatios Ratios that the take in will be split by.
    function convertOfferToAuction(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        uint256 _lengthOfAuction,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        (bool success, bytes memory data) = superRareAuctionHouse.delegatecall(
            abi.encodeWithSelector(
                this.convertOfferToAuction.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _amount,
                _lengthOfAuction,
                _splitAddresses,
                _splitRatios
            )
        );
        require(success, string(data));
    }
    /// @notice Cancels a configured Auction that has not started.
    /// @dev Requires the person sending the message to be the auction creator or token owner.
    /// @param _originContract Contract address of the asset pending auction.
    /// @param _tokenId Token Id of the asset.
    function cancelAuction(address _originContract, uint256 _tokenId)
        external
        override
    {
        (bool success, bytes memory data) = superRareAuctionHouse.delegatecall(
            abi.encodeWithSelector(
                this.cancelAuction.selector,
                _originContract,
                _tokenId
            )
        );
        require(success, string(data));
    }
    /// @notice Places a bid on a valid auction.
    /// @dev Only the configured currency can be used (Zero address for eth)
    /// @param _originContract Contract address of asset being bid on.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of currency being used to bid.
    /// @param _amount Amount of the currency being used for the bid.
    function bid(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable override {
        (bool success, bytes memory data) = superRareAuctionHouse.delegatecall(
            abi.encodeWithSelector(
                this.bid.selector,
                _originContract,
                _tokenId,
                _currencyAddress,
                _amount
            )
        );
        require(success, string(data));
    }
    /// @notice Settles an auction that has ended.
    /// @dev Anyone is able to settle an auction since non-input params are used.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    function settleAuction(address _originContract, uint256 _tokenId)
        external
        override
    {
        (bool success, bytes memory data) = superRareAuctionHouse.delegatecall(
            abi.encodeWithSelector(
                this.settleAuction.selector,
                _originContract,
                _tokenId
            )
        );
        require(success, string(data));
    }
    /// @notice Grabs the current auction details for a token.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    /** @return Auction Struct: creatorAddress, creationTime, startingTime, lengthOfAuction,
                currencyAddress, minimumBid, auctionType, splitRecipients array, and splitRatios array.
    */
    function getAuctionDetails(address _originContract, uint256 _tokenId)
        external
        view
        override
        returns (
            address,
            uint256,
            uint256,
            uint256,
            address,
            uint256,
            bytes32,
            address payable[] memory,
            uint8[] memory
        )
    {
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        return (
            auction.auctionCreator,
            auction.creationBlock,
            auction.startingTime,
            auction.lengthOfAuction,
            auction.currencyAddress,
            auction.minimumBid,
            auction.auctionType,
            auction.splitRecipients,
            auction.splitRatios
        );
    }
    function getSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _target
    )
        external
        view
        override
        returns (
            address,
            address,
            uint256,
            address payable[] memory,
            uint8[] memory
        )
    {
        SalePrice memory sp = tokenSalePrices[_originContract][_tokenId][
            _target
        ];
        return (
            sp.seller,
            sp.currencyAddress,
            sp.amount,
            sp.splitRecipients,
            sp.splitRatios
        );
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }
    function __Ownable_init_unchained() internal initializer {
        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;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../proxy/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal initializer {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
import "../../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;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "../../marketplace/IMarketplaceSettings.sol";
import "../../royalty/creator/IERC721CreatorRoyalty.sol";
import "../../payments/IPayments.sol";
import "../../registry/spaces/ISpaceOperatorRegistry.sol";
import "../../registry/token/IApprovedTokenRegistry.sol";
import "../../royalty/creator/IRoyaltyEngine.sol";
/// @author koloz
/// @title SuperRareBazaar Storage Contract
/// @dev STORAGE CAN ONLY BE APPENDED NOT INSERTED OR MODIFIED
contract SuperRareBazaarStorage {
    /////////////////////////////////////////////////////////////////////////
    // Constants
    /////////////////////////////////////////////////////////////////////////
    // Auction Types
    bytes32 public constant COLDIE_AUCTION = "COLDIE_AUCTION";
    bytes32 public constant SCHEDULED_AUCTION = "SCHEDULED_AUCTION";
    bytes32 public constant NO_AUCTION = bytes32(0);
    /////////////////////////////////////////////////////////////////////////
    // Structs
    /////////////////////////////////////////////////////////////////////////
    // The Offer truct for a given token:
    // buyer - address of person making the offer
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // amount - offer in wei/full erc20 value
    // marketplaceFee - the amount that is taken by the network on offer acceptance.
    struct Offer {
        address payable buyer;
        uint256 amount;
        uint256 timestamp;
        uint8 marketplaceFee;
        bool convertible;
    }
    // The Sale Price struct for a given token:
    // seller - address of the person selling the token
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // amount - offer in wei/full erc20 value
    struct SalePrice {
        address payable seller;
        address currencyAddress;
        uint256 amount;
        address payable[] splitRecipients;
        uint8[] splitRatios;
    }
    // Structure of an Auction:
    // auctionCreator - creator of the auction
    // creationBlock - time that the auction was created/configured
    // startingBlock - time that the auction starts on
    // lengthOfAuction - how long the auction is
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // minimumBid - min amount a bidder can bid at the start of an auction.
    // auctionType - type of auction, represented as the formatted bytes 32 string
    struct Auction {
        address payable auctionCreator;
        uint256 creationBlock;
        uint256 startingTime;
        uint256 lengthOfAuction;
        address currencyAddress;
        uint256 minimumBid;
        bytes32 auctionType;
        address payable[] splitRecipients;
        uint8[] splitRatios;
    }
    struct Bid {
        address payable bidder;
        address currencyAddress;
        uint256 amount;
        uint8 marketplaceFee;
    }
    /////////////////////////////////////////////////////////////////////////
    // Events
    /////////////////////////////////////////////////////////////////////////
    event Sold(
        address indexed _originContract,
        address indexed _buyer,
        address indexed _seller,
        address _currencyAddress,
        uint256 _amount,
        uint256 _tokenId
    );
    event SetSalePrice(
        address indexed _originContract,
        address indexed _currencyAddress,
        address _target,
        uint256 _amount,
        uint256 _tokenId,
        address payable[] _splitRecipients,
        uint8[] _splitRatios
    );
    event OfferPlaced(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _currencyAddress,
        uint256 _amount,
        uint256 _tokenId,
        bool _convertible
    );
    event AcceptOffer(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _seller,
        address _currencyAddress,
        uint256 _amount,
        uint256 _tokenId,
        address payable[] _splitAddresses,
        uint8[] _splitRatios
    );
    event CancelOffer(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _currencyAddress,
        uint256 _amount,
        uint256 _tokenId
    );
    event NewAuction(
        address indexed _contractAddress,
        uint256 indexed _tokenId,
        address indexed _auctionCreator,
        address _currencyAddress,
        uint256 _startingTime,
        uint256 _minimumBid,
        uint256 _lengthOfAuction
    );
    event CancelAuction(
        address indexed _contractAddress,
        uint256 indexed _tokenId,
        address indexed _auctionCreator
    );
    event AuctionBid(
        address indexed _contractAddress,
        address indexed _bidder,
        uint256 indexed _tokenId,
        address _currencyAddress,
        uint256 _amount,
        bool _startedAuction,
        uint256 _newAuctionLength,
        address _previousBidder
    );
    event AuctionSettled(
        address indexed _contractAddress,
        address indexed _bidder,
        address _seller,
        uint256 indexed _tokenId,
        address _currencyAddress,
        uint256 _amount
    );
    /////////////////////////////////////////////////////////////////////////
    // State Variables
    /////////////////////////////////////////////////////////////////////////
    // Current marketplace settings implementation to be used
    IMarketplaceSettings public marketplaceSettings;
    // Current creator royalty implementation to be used
    IERC721CreatorRoyalty public royaltyRegistry;
    // Address of the global royalty engine being used.
    IRoyaltyEngineV1 public royaltyEngine;
    // Current SuperRareMarketplace implementation to be used
    address public superRareMarketplace;
    // Current SuperRareAuctionHouse implementation to be used
    address public superRareAuctionHouse;
    // Current SpaceOperatorRegistry implementation to be used.
    ISpaceOperatorRegistry public spaceOperatorRegistry;
    // Current ApprovedTokenRegistry implementation being used for currencies.
    IApprovedTokenRegistry public approvedTokenRegistry;
    // Current payments contract to use
    IPayments public payments;
    // Address to be used for staking registry.
    address public stakingRegistry;
    // Address of the network beneficiary
    address public networkBeneficiary;
    // A minimum increase in bid amount when out bidding someone.
    uint8 public minimumBidIncreasePercentage; // 10 = 10%
    // Maximum length that an auction can be.
    uint256 public maxAuctionLength;
    // Extension length for an auction
    uint256 public auctionLengthExtension;
    // Offer cancellation delay
    uint256 public offerCancelationDelay;
    // Mapping from contract to mapping of tokenId to mapping of target to sale price.
    mapping(address => mapping(uint256 => mapping(address => SalePrice)))
        public tokenSalePrices;
    // Mapping from contract to mapping of tokenId to mapping of currency address to Current Offer.
    mapping(address => mapping(uint256 => mapping(address => Offer)))
        public tokenCurrentOffers;
    // Mapping from contract to mapping of tokenId to Auction.
    mapping(address => mapping(uint256 => Auction)) public tokenAuctions;
    // Mapping from contract to mapping of tokenId to Bid.
    mapping(address => mapping(uint256 => Bid)) public auctionBids;
    uint256[50] private __gap;
    /// ALL NEW STORAGE MUST COME AFTER THIS
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title ISuperRareBazaar
/// @notice Interface for the SuperRareBazaar Contract
interface ISuperRareBazaar {
    // Marketplace Functions
    // Buyer
    /// @notice Create an offer for a given asset
    /// @param _originContract Contract address of the asset being listed.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the token being offered.
    /// @param _amount Amount being offered.
    /// @param _convertible If the offer can be converted into an auction
    function offer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        bool _convertible
    ) external payable;
    /// @notice Purchases the token for the current sale price.
    /// @param _originContract Contract address for asset being bought.
    /// @param _tokenId TokenId of asset being bought.
    /// @param _currencyAddress Currency address of asset being used to buy.
    /// @param _amount Amount the piece if being bought for.
    function buy(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable;
    /// @notice Cancels an existing offer the sender has placed on a piece.
    /// @param _originContract Contract address of token.
    /// @param _tokenId TokenId that has an offer.
    /// @param _currencyAddress Currency address of the offer.
    function cancelOffer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress
    ) external;
    // Seller
    /// @notice Sets a sale price for the given asset(s).
    /// @param _originContract Contract address of the asset being listed.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Contract address of the currency asset is being listed for.
    /// @param _listPrice Amount of the currency the asset is being listed for (including all decimal points).
    /// @param _target Address of the person this sale price is target to.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function setSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _listPrice,
        address _target,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    /// @notice Removes the current sale price of an asset for the given currency.
    /// @param _originContract The origin contract of the asset.
    /// @param _tokenId The tokenId of the asset within the _originContract.
    /// @param _target The address of the person
    function removeSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _target
    ) external;
    /// @notice Accept an offer placed on _originContract : _tokenId.
    /// @param _originContract Contract of the asset the offer was made on.
    /// @param _tokenId TokenId of the asset.
    /// @param _currencyAddress Address of the currency used for the offer.
    /// @param _amount Amount the offer was for/and is being accepted.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function acceptOffer(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    // Auction House
    // Anyone
    /// @notice Settles an auction that has ended.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    function settleAuction(address _originContract, uint256 _tokenId) external;
    // Buyer
    /// @notice Places a bid on a valid auction.
    /// @param _originContract Contract address of asset being bid on.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of currency being used to bid.
    /// @param _amount Amount of the currency being used for the bid.
    function bid(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable;
    // Seller
    /// @notice Configures an Auction for a given asset.
    /// @param _auctionType The type of auction being configured.
    /// @param _originContract Contract address of the asset being put up for auction.
    /// @param _tokenId Token Id of the asset.
    /// @param _startingAmount The reserve price or min bid of an auction.
    /// @param _currencyAddress The currency the auction is being conducted in.
    /// @param _lengthOfAuction The amount of time in seconds that the auction is configured for.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function configureAuction(
        bytes32 _auctionType,
        address _originContract,
        uint256 _tokenId,
        uint256 _startingAmount,
        address _currencyAddress,
        uint256 _lengthOfAuction,
        uint256 _startTime,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    /// @notice Cancels a configured Auction that has not started.
    /// @param _originContract Contract address of the asset pending auction.
    /// @param _tokenId Token Id of the asset.
    function cancelAuction(address _originContract, uint256 _tokenId) external;
    /// @notice Converts an offer into a coldie auction.
    /// @param _originContract Contract address of the asset.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the currency being converted.
    /// @param _amount Amount being converted into an auction.
    /// @param _lengthOfAuction Number of seconds the auction will last.
    /// @param _splitAddresses Addresses that the sellers take in will be split amongst.
    /// @param _splitRatios Ratios that the take in will be split by.
    function convertOfferToAuction(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        uint256 _lengthOfAuction,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    /// @notice Grabs the current auction details for a token.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    /** @return Auction Struct: creatorAddress, creationTime, startingTime, lengthOfAuction,
                currencyAddress, minimumBid, auctionType, splitRecipients array, and splitRatios array.
    */
    function getAuctionDetails(address _originContract, uint256 _tokenId)
        external
        view
        returns (
            address,
            uint256,
            uint256,
            uint256,
            address,
            uint256,
            bytes32,
            address payable[] calldata,
            uint8[] calldata
        );
    function getSalePrice(
        address _originContract,
        uint256 _tokenId,
        address _target
    )
        external
        view
        returns (
            address,
            address,
            uint256,
            address payable[] memory,
            uint8[] memory
        );
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";
/*
 * @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 GSN 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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;
import "../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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);
    }
    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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/**
 * @title IMarketplaceSettings Settings governing a marketplace.
 */
interface IMarketplaceSettings {
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Min and Max Values
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMaxValue() external view returns (uint256);
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMinValue() external view returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the marketplace fee percentage.
     * @return uint8 wei fee.
     */
    function getMarketplaceFeePercentage() external view returns (uint8);
    /**
     * @dev Utility function for calculating the marketplace fee for given amount of wei.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculateMarketplaceFee(uint256 _amount)
        external
        view
        returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Primary Sale Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the primary sale fee percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @return uint8 wei primary sale fee.
     */
    function getERC721ContractPrimarySaleFeePercentage(address _contractAddress)
        external
        view
        returns (uint8);
    /**
     * @dev Utility function for calculating the primary sale fee for given amount of wei
     * @param _contractAddress address ERC721Contract address.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculatePrimarySaleFee(address _contractAddress, uint256 _amount)
        external
        view
        returns (uint256);
    /**
     * @dev Check whether the ERC721 token has sold at least once.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @return bool of whether the token has sold.
     */
    function hasERC721TokenSold(address _contractAddress, uint256 _tokenId)
        external
        view
        returns (bool);
    /**
     * @dev Mark a token as sold.
     * Requirements:
     *
     * - `_contractAddress` cannot be the zero address.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @param _hasSold bool of whether the token should be marked sold or not.
     */
    function markERC721Token(
        address _contractAddress,
        uint256 _tokenId,
        bool _hasSold
    ) external;
    function setERC721ContractPrimarySaleFeePercentage(
        address _contractAddress,
        uint8 _percentage
    ) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "../../token/ERC721/IERC721TokenCreator.sol";
/**
 * @title IERC721CreatorRoyalty Token level royalty interface.
 */
interface IERC721CreatorRoyalty is IERC721TokenCreator {
    /**
     * @dev Get the royalty fee percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @return uint8 wei royalty fee.
     */
    function getERC721TokenRoyaltyPercentage(
        address _contractAddress,
        uint256 _tokenId
    ) external view returns (uint8);
    /**
     * @dev Utililty function to calculate the royalty fee for a token.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculateRoyaltyFee(
        address _contractAddress,
        uint256 _tokenId,
        uint256 _amount
    ) external view returns (uint256);
    /**
     * @dev Utililty function to set the royalty percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @param _percentage percentage for royalty
     */
    function setPercentageForSetERC721ContractRoyalty(
        address _contractAddress,
        uint8 _percentage
    ) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title IPayments
/// @notice Interface for the Payments contract used.
interface IPayments {
    function refund(address _payee, uint256 _amount) external payable;
    function payout(address[] calldata _splits, uint256[] calldata _amounts)
        external
        payable;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title ISpaceOperatorRegistry
/// @notice The interface for the SpaceOperatorRegistry
interface ISpaceOperatorRegistry {
    function getPlatformCommission(address _operator)
        external
        view
        returns (uint8);
    function setPlatformCommission(address _operator, uint8 _commission)
        external;
    function isApprovedSpaceOperator(address _operator)
        external
        view
        returns (bool);
    function setSpaceOperatorApproved(address _operator, bool _approved)
        external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
interface IApprovedTokenRegistry {
    /// @notice Returns if a token has been approved or not.
    /// @param _tokenContract Contract of token being checked.
    /// @return True if the token is allowed, false otherwise.
    function isApprovedToken(address _tokenContract)
        external
        view
        returns (bool);
    /// @notice Adds a token to the list of approved tokens.
    /// @param _tokenContract Contract of token being approved.
    function addApprovedToken(address _tokenContract) external;
    /// @notice Removes a token from the approved tokens list.
    /// @param _tokenContract Contract of token being approved.
    function removeApprovedToken(address _tokenContract) external;
    /// @notice Sets whether all token contracts should be approved.
    /// @param _allTokensApproved Bool denoting if all tokens should be approved.
    function setAllTokensApproved(bool _allTokensApproved) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author: manifold.xyz
/**
 * @dev Lookup engine interface
 */
interface IRoyaltyEngineV1 {
    /**
     * Get the royalty for a given token (address, id) and value amount.  Does not cache the bps/amounts.  Caches the spec for a given token address
     *
     * @param tokenAddress - The address of the token
     * @param tokenId      - The id of the token
     * @param value        - The value you wish to get the royalty of
     *
     * returns Two arrays of equal length, royalty recipients and the corresponding amount each recipient should get
     */
    function getRoyalty(
        address tokenAddress,
        uint256 tokenId,
        uint256 value
    )
        external
        returns (address payable[] memory recipients, uint256[] memory amounts);
    /**
     * View only version of getRoyalty
     *
     * @param tokenAddress - The address of the token
     * @param tokenId      - The id of the token
     * @param value        - The value you wish to get the royalty of
     *
     * returns Two arrays of equal length, royalty recipients and the corresponding amount each recipient should get
     */
    function getRoyaltyView(
        address tokenAddress,
        uint256 tokenId,
        uint256 value
    )
        external
        view
        returns (address payable[] memory recipients, uint256[] memory amounts);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
interface IERC721TokenCreator {
    function tokenCreator(address _contractAddress, uint256 _tokenId)
        external
        view
        returns (address payable);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-upgradeable-0.7.2/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/utils/ReentrancyGuardUpgradeable.sol";
import "./ISuperRareAuctionHouse.sol";
import "../SuperRareBazaarBase.sol";
/// @author koloz
/// @title SuperRareAuctionHouse
/// @notice The logic for all functions related to the SuperRareAuctionHouse.
contract SuperRareAuctionHouse is
    ISuperRareAuctionHouse,
    OwnableUpgradeable,
    ReentrancyGuardUpgradeable,
    SuperRareBazaarBase
{
    using SafeMath for uint256;
    using SafeERC20 for IERC20;
    /////////////////////////////////////////////////////////////////////////
    // Initializer
    /////////////////////////////////////////////////////////////////////////
    function initialize(
        address _marketplaceSettings,
        address _royaltyRegistry,
        address _royaltyEngine,
        address _spaceOperatorRegistry,
        address _approvedTokenRegistry,
        address _payments,
        address _stakingRegistry,
        address _networkBeneficiary
    ) public initializer {
        require(_marketplaceSettings != address(0));
        require(_royaltyRegistry != address(0));
        require(_royaltyEngine != address(0));
        require(_spaceOperatorRegistry != address(0));
        require(_approvedTokenRegistry != address(0));
        require(_payments != address(0));
        require(_networkBeneficiary != address(0));
        marketplaceSettings = IMarketplaceSettings(_marketplaceSettings);
        royaltyRegistry = IERC721CreatorRoyalty(_royaltyRegistry);
        royaltyEngine = IRoyaltyEngineV1(_royaltyEngine);
        spaceOperatorRegistry = ISpaceOperatorRegistry(_spaceOperatorRegistry);
        approvedTokenRegistry = IApprovedTokenRegistry(_approvedTokenRegistry);
        payments = IPayments(_payments);
        stakingRegistry = _stakingRegistry;
        networkBeneficiary = _networkBeneficiary;
        minimumBidIncreasePercentage = 10;
        maxAuctionLength = 7 days;
        auctionLengthExtension = 15 minutes;
        offerCancelationDelay = 5 minutes;
        __Ownable_init();
        __ReentrancyGuard_init();
    }
    /// @notice Configures an Auction for a given asset.
    /// @dev If auction type is coldie (reserve) then _startingAmount cant be 0.
    /// @dev _currencyAddress equal to the zero address denotes eth.
    /// @dev All time related params are unix epoch timestamps.
    /// @param _auctionType The type of auction being configured.
    /// @param _originContract Contract address of the asset being put up for auction.
    /// @param _tokenId Token Id of the asset.
    /// @param _startingAmount The reserve price or min bid of an auction.
    /// @param _currencyAddress The currency the auction is being conducted in.
    /// @param _lengthOfAuction The amount of time in seconds that the auction is configured for.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function configureAuction(
        bytes32 _auctionType,
        address _originContract,
        uint256 _tokenId,
        uint256 _startingAmount,
        address _currencyAddress,
        uint256 _lengthOfAuction,
        uint256 _startTime,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        _checkIfCurrencyIsApproved(_currencyAddress);
        _senderMustBeTokenOwner(_originContract, _tokenId);
        _ownerMustHaveMarketplaceApprovedForNFT(_originContract, _tokenId);
        _checkSplits(_splitAddresses, _splitRatios);
        _checkValidAuctionType(_auctionType);
        require(
            _lengthOfAuction <= maxAuctionLength,
            "configureAuction::Auction too long."
        );
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        require(
            auction.auctionType == NO_AUCTION ||
                auction.auctionCreator != msg.sender,
            "configureAuction::Cannot have a current auction."
        );
        require(_lengthOfAuction > 0, "configureAuction::Length must be > 0");
        if (_auctionType == COLDIE_AUCTION) {
            require(
                _startingAmount > 0,
                "configureAuction::Coldie starting price must be > 0"
            );
        } else if (_auctionType == SCHEDULED_AUCTION) {
            require(
                _startTime > block.timestamp,
                "configureAuction::Scheduled auction cannot start in past."
            );
        }
        require(
            _startingAmount <= marketplaceSettings.getMarketplaceMaxValue(),
            "configureAuction::Cannot set starting price higher than max value."
        );
        tokenAuctions[_originContract][_tokenId] = Auction(
            msg.sender,
            block.number,
            _auctionType == COLDIE_AUCTION ? 0 : _startTime,
            _lengthOfAuction,
            _currencyAddress,
            _startingAmount,
            _auctionType,
            _splitAddresses,
            _splitRatios
        );
        if (_auctionType == SCHEDULED_AUCTION) {
            IERC721 erc721 = IERC721(_originContract);
            erc721.transferFrom(msg.sender, address(this), _tokenId);
        }
        emit NewAuction(
            _originContract,
            _tokenId,
            msg.sender,
            _currencyAddress,
            _startTime,
            _startingAmount,
            _lengthOfAuction
        );
    }
    /// @notice Converts an offer into a coldie auction.
    /// @param _originContract Contract address of the asset.
    /// @dev Covers use of any currency (0 address is eth).
    /// @dev Only covers converting an offer to a coldie auction.
    /// @dev Cant convert offer if an auction currently exists.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the currency being converted.
    /// @param _amount Amount being converted into an auction.
    /// @param _lengthOfAuction Number of seconds the auction will last.
    /// @param _splitAddresses Addresses that the sellers take in will be split amongst.
    /// @param _splitRatios Ratios that the take in will be split by.
    function convertOfferToAuction(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        uint256 _lengthOfAuction,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external override {
        _senderMustBeTokenOwner(_originContract, _tokenId);
        _ownerMustHaveMarketplaceApprovedForNFT(_originContract, _tokenId);
        _checkSplits(_splitAddresses, _splitRatios);
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        require(
            auction.auctionType == NO_AUCTION ||
                auction.auctionCreator != msg.sender,
            "convertOfferToAuction::Cannot have a current auction."
        );
        require(
            _lengthOfAuction <= maxAuctionLength,
            "convertOfferToAuction::Auction too long."
        );
        Offer memory currOffer = tokenCurrentOffers[_originContract][_tokenId][
            _currencyAddress
        ];
        require(currOffer.buyer != msg.sender, "convert::own offer");
        require(
            currOffer.convertible,
            "convertOfferToAuction::Offer is not convertible"
        );
        require(
            currOffer.amount == _amount,
            "convertOfferToAuction::Converting offer with different amount."
        );
        tokenAuctions[_originContract][_tokenId] = Auction(
            msg.sender,
            block.number,
            block.timestamp,
            _lengthOfAuction,
            _currencyAddress,
            currOffer.amount,
            COLDIE_AUCTION,
            _splitAddresses,
            _splitRatios
        );
        delete tokenCurrentOffers[_originContract][_tokenId][_currencyAddress];
        auctionBids[_originContract][_tokenId] = Bid(
            currOffer.buyer,
            _currencyAddress,
            _amount,
            marketplaceSettings.getMarketplaceFeePercentage()
        );
        IERC721 erc721 = IERC721(_originContract);
        erc721.transferFrom(msg.sender, address(this), _tokenId);
        emit NewAuction(
            _originContract,
            _tokenId,
            msg.sender,
            _currencyAddress,
            block.timestamp,
            _amount,
            _lengthOfAuction
        );
        emit AuctionBid(
            _originContract,
            currOffer.buyer,
            _tokenId,
            _currencyAddress,
            _amount,
            true,
            0,
            address(0)
        );
    }
    /// @notice Cancels a configured Auction that has not started.
    /// @dev Requires the person sending the message to be the auction creator or token owner.
    /// @param _originContract Contract address of the asset pending auction.
    /// @param _tokenId Token Id of the asset.
    function cancelAuction(address _originContract, uint256 _tokenId)
        external
        override
    {
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        IERC721 erc721 = IERC721(_originContract);
        require(
            auction.auctionType != NO_AUCTION,
            "cancelAuction::Must have an auction configured."
        );
        require(
            auction.startingTime == 0 || block.timestamp < auction.startingTime,
            "cancelAuction::Auction must not have started."
        );
        require(
            auction.auctionCreator == msg.sender ||
                erc721.ownerOf(_tokenId) == msg.sender,
            "cancelAuction::Must be creator or owner."
        );
        delete tokenAuctions[_originContract][_tokenId];
        if (erc721.ownerOf(_tokenId) == address(this)) {
            erc721.transferFrom(address(this), msg.sender, _tokenId);
        }
        emit CancelAuction(_originContract, _tokenId, auction.auctionCreator);
    }
    /// @notice Places a bid on a valid auction.
    /// @dev Only the configured currency can be used (Zero address for eth)
    /// @param _originContract Contract address of asset being bid on.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of currency being used to bid.
    /// @param _amount Amount of the currency being used for the bid.
    function bid(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable override nonReentrant {
        uint256 requiredAmount = _amount.add(
            marketplaceSettings.calculateMarketplaceFee(_amount)
        );
        _senderMustHaveMarketplaceApproved(_currencyAddress, requiredAmount);
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        require(
            auction.auctionType != NO_AUCTION,
            "bid::Must have a current auction."
        );
        require(
            auction.auctionCreator != msg.sender,
            "bid::Cannot bid on your own auction."
        );
        require(
            block.timestamp >= auction.startingTime,
            "bid::Auction not active."
        );
        require(
            _currencyAddress == auction.currencyAddress,
            "bid::Currency must be in configured denomination"
        );
        require(_amount > 0, "bid::Cannot be 0");
        require(
            _amount <= marketplaceSettings.getMarketplaceMaxValue(),
            "bid::Must be less than max value."
        );
        require(
            _amount >= auction.minimumBid,
            "bid::Cannot be lower than minimum bid."
        );
        require(
            auction.startingTime == 0 ||
                block.timestamp <
                auction.startingTime.add(auction.lengthOfAuction),
            "bid::Must be active."
        );
        Bid memory currBid = auctionBids[_originContract][_tokenId];
        require(
            _amount >=
                currBid.amount.add(
                    currBid.amount.mul(minimumBidIncreasePercentage).div(100)
                ),
            "bid::Must be higher than prev bid + min increase."
        );
        IERC721 erc721 = IERC721(_originContract);
        address tokenOwner = erc721.ownerOf(_tokenId);
        require(
            auction.auctionCreator == tokenOwner || tokenOwner == address(this),
            "bid::Auction creator must be owner."
        );
        if (auction.auctionCreator == tokenOwner) {
            _ownerMustHaveMarketplaceApprovedForNFT(_originContract, _tokenId);
        }
        _checkAmountAndTransfer(_currencyAddress, requiredAmount);
        _refund(
            _currencyAddress,
            currBid.amount,
            currBid.marketplaceFee,
            currBid.bidder
        );
        auctionBids[_originContract][_tokenId] = Bid(
            msg.sender,
            _currencyAddress,
            _amount,
            marketplaceSettings.getMarketplaceFeePercentage()
        );
        bool startedAuction = false;
        uint256 newAuctionLength = 0;
        if (auction.startingTime == 0) {
            tokenAuctions[_originContract][_tokenId].startingTime = block
                .timestamp;
            erc721.transferFrom(
                auction.auctionCreator,
                address(this),
                _tokenId
            );
            startedAuction = true;
        } else if (
            auction.startingTime.add(auction.lengthOfAuction).sub(
                block.timestamp
            ) < auctionLengthExtension
        ) {
            newAuctionLength = block.timestamp.add(auctionLengthExtension).sub(
                auction.startingTime
            );
            tokenAuctions[_originContract][_tokenId]
                .lengthOfAuction = newAuctionLength;
        }
        emit AuctionBid(
            _originContract,
            msg.sender,
            _tokenId,
            _currencyAddress,
            _amount,
            startedAuction,
            newAuctionLength,
            currBid.bidder
        );
    }
    /// @notice Settles an auction that has ended.
    /// @dev Anyone is able to settle an auction since non-input params are used.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    function settleAuction(address _originContract, uint256 _tokenId)
        external
        override
    {
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        require(
            auction.auctionType != NO_AUCTION && auction.startingTime != 0,
            "settleAuction::Must have a current valid auction."
        );
        require(
            block.timestamp >=
                auction.startingTime.add(auction.lengthOfAuction),
            "settleAuction::Can only settle ended auctions."
        );
        Bid memory currBid = auctionBids[_originContract][_tokenId];
        delete tokenAuctions[_originContract][_tokenId];
        delete auctionBids[_originContract][_tokenId];
        IERC721 erc721 = IERC721(_originContract);
        if (currBid.bidder == address(0)) {
            erc721.transferFrom(
                address(this),
                auction.auctionCreator,
                _tokenId
            );
        } else {
            erc721.transferFrom(address(this), currBid.bidder, _tokenId);
            _payout(
                _originContract,
                _tokenId,
                auction.currencyAddress,
                currBid.amount,
                auction.auctionCreator,
                auction.splitRecipients,
                auction.splitRatios
            );
            marketplaceSettings.markERC721Token(
                _originContract,
                _tokenId,
                true
            );
        }
        emit AuctionSettled(
            _originContract,
            currBid.bidder,
            auction.auctionCreator,
            _tokenId,
            auction.currencyAddress,
            currBid.amount
        );
    }
    /// @notice Grabs the current auction details for a token.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    /** @return Auction Struct: creatorAddress, creationTime, startingTime, lengthOfAuction,
                currencyAddress, minimumBid, auctionType, splitRecipients array, and splitRatios array.
    */
    function getAuctionDetails(address _originContract, uint256 _tokenId)
        external
        view
        override
        returns (
            address,
            uint256,
            uint256,
            uint256,
            address,
            uint256,
            bytes32,
            address payable[] memory,
            uint8[] memory
        )
    {
        Auction memory auction = tokenAuctions[_originContract][_tokenId];
        return (
            auction.auctionCreator,
            auction.creationBlock,
            auction.startingTime,
            auction.lengthOfAuction,
            auction.currencyAddress,
            auction.minimumBid,
            auction.auctionType,
            auction.splitRecipients,
            auction.splitRatios
        );
    }
    function _checkValidAuctionType(bytes32 _auctionType) internal pure {
        if (
            _auctionType != COLDIE_AUCTION && _auctionType != SCHEDULED_AUCTION
        ) {
            revert("Invalid Auction Type");
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }
    function __Ownable_init_unchained() internal initializer {
        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;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../proxy/Initializable.sol";
/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.
    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;
    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }
    function __ReentrancyGuard_init_unchained() internal initializer {
        _status = _NOT_ENTERED;
    }
    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title ISuperRareAuctionHouse
/// @notice The interface for the SuperRareAuctionHouse Functions.
interface ISuperRareAuctionHouse {
    /// @notice Configures an Auction for a given asset.
    /// @param _auctionType The type of auction being configured.
    /// @param _originContract Contract address of the asset being put up for auction.
    /// @param _tokenId Token Id of the asset.
    /// @param _startingAmount The reserve price or min bid of an auction.
    /// @param _currencyAddress The currency the auction is being conducted in.
    /// @param _lengthOfAuction The amount of time in seconds that the auction is configured for.
    /// @param _splitAddresses Addresses to split the sellers commission with.
    /// @param _splitRatios The ratio for the split corresponding to each of the addresses being split with.
    function configureAuction(
        bytes32 _auctionType,
        address _originContract,
        uint256 _tokenId,
        uint256 _startingAmount,
        address _currencyAddress,
        uint256 _lengthOfAuction,
        uint256 _startTime,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    /// @notice Converts an offer into a coldie auction.
    /// @param _originContract Contract address of the asset.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of the currency being converted.
    /// @param _amount Amount being converted into an auction.
    /// @param _lengthOfAuction Number of seconds the auction will last.
    /// @param _splitAddresses Addresses that the sellers take in will be split amongst.
    /// @param _splitRatios Ratios that the take in will be split by.
    function convertOfferToAuction(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        uint256 _lengthOfAuction,
        address payable[] calldata _splitAddresses,
        uint8[] calldata _splitRatios
    ) external;
    /// @notice Cancels a configured Auction that has not started.
    /// @param _originContract Contract address of the asset pending auction.
    /// @param _tokenId Token Id of the asset.
    function cancelAuction(address _originContract, uint256 _tokenId) external;
    /// @notice Places a bid on a valid auction.
    /// @param _originContract Contract address of asset being bid on.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of currency being used to bid.
    /// @param _amount Amount of the currency being used for the bid.
    function bid(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount
    ) external payable;
    /// @notice Settles an auction that has ended.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    function settleAuction(address _originContract, uint256 _tokenId) external;
    /// @notice Grabs the current auction details for a token.
    /// @param _originContract Contract address of asset.
    /// @param _tokenId Token Id of the asset.
    /** @return Auction Struct: creatorAddress, creationTime, startingTime, lengthOfAuction,
                currencyAddress, minimumBid, auctionType, splitRecipients array, and splitRatios array.
    */
    function getAuctionDetails(address _originContract, uint256 _tokenId)
        external
        view
        returns (
            address,
            uint256,
            uint256,
            uint256,
            address,
            uint256,
            bytes32,
            address payable[] memory,
            uint8[] memory
        );
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-0.7.2/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts-0.7.2/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts-0.7.2/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts-0.7.2/math/SafeMath.sol";
import "./storage/SuperRareBazaarStorage.sol";
/// @author koloz
/// @title SuperRareBazaarBase
/// @notice Base contract containing the internal functions for the SuperRareBazaar.
abstract contract SuperRareBazaarBase is SuperRareBazaarStorage {
    using SafeMath for uint256;
    using SafeMath for uint8;
    using SafeERC20 for IERC20;
    /////////////////////////////////////////////////////////////////////////
    // Internal Functions
    /////////////////////////////////////////////////////////////////////////
    /// @notice Checks to see if the currenccy address is eth or an approved erc20 token.
    /// @param _currencyAddress Address of currency (Zero address if eth).
    function _checkIfCurrencyIsApproved(address _currencyAddress)
        internal
        view
    {
        require(
            _currencyAddress == address(0) ||
                approvedTokenRegistry.isApprovedToken(_currencyAddress),
            "Not approved currency"
        );
    }
    /// @notice Checks to see if the owner of the token has the marketplace approved.
    /// @param _originContract Contract address of the token being checked.
    /// @param _tokenId Token Id of the asset.
    function _ownerMustHaveMarketplaceApprovedForNFT(
        address _originContract,
        uint256 _tokenId
    ) internal view {
        IERC721 erc721 = IERC721(_originContract);
        address owner = erc721.ownerOf(_tokenId);
        require(
            erc721.isApprovedForAll(owner, address(this)),
            "owner must have approved contract"
        );
    }
    /// @notice Checks to see if the msg sender owns the token.
    /// @param _originContract Contract address of the token being checked.
    /// @param _tokenId Token Id of the asset.
    function _senderMustBeTokenOwner(address _originContract, uint256 _tokenId)
        internal
        view
    {
        IERC721 erc721 = IERC721(_originContract);
        require(
            erc721.ownerOf(_tokenId) == msg.sender,
            "sender must be the token owner"
        );
    }
    /// @notice Verifies that the splits supplied are valid.
    /// @dev A valid split has the same number of splits and ratios.
    /// @dev There can only be a max of 5 parties split with.
    /// @dev Total of the ratios should be 100 which is relative.
    /// @param _splits The addresses the amount is being split with.
    /// @param _ratios The ratios each address in _splits is getting.
    function _checkSplits(
        address payable[] calldata _splits,
        uint8[] calldata _ratios
    ) internal pure {
        require(_splits.length > 0, "checkSplits::Must have at least 1 split");
        require(_splits.length <= 5, "checkSplits::Split exceeded max size");
        require(
            _splits.length == _ratios.length,
            "checkSplits::Splits and ratios must be equal"
        );
        uint256 totalRatio = 0;
        for (uint256 i = 0; i < _ratios.length; i++) {
            totalRatio += _ratios[i];
        }
        require(totalRatio == 100, "checkSplits::Total must be equal to 100");
    }
    /// @notice Checks to see if the sender has approved the marketplace to move tokens.
    /// @dev This is for offers/buys/bids and the allowance of erc20 tokens.
    /// @dev Returns on zero address because no allowance is needed for eth.
    /// @param _contract The address of the currency being checked.
    /// @param _amount The total amount being checked.
    function _senderMustHaveMarketplaceApproved(
        address _contract,
        uint256 _amount
    ) internal view {
        if (_contract == address(0)) {
            return;
        }
        IERC20 erc20 = IERC20(_contract);
        require(
            erc20.allowance(msg.sender, address(this)) >= _amount,
            "sender needs to approve marketplace for currency"
        );
    }
    /// @notice Checks the user has the correct amount and transfers to the marketplace.
    /// @dev If the currency used is eth (zero address) the msg value is checked.
    /// @dev If eth isnt used and eth is sent we revert the txn.
    /// @dev We need to check this contracts balance before and after the transfer to ensure no fee.
    /// @param _currencyAddress Currency address being checked and transfered.
    /// @param _amount Total amount of currency.
    function _checkAmountAndTransfer(address _currencyAddress, uint256 _amount)
        internal
    {
        if (_currencyAddress == address(0)) {
            require(msg.value == _amount, "not enough eth sent");
            return;
        }
        require(msg.value == 0, "msg.value should be 0 when not using eth");
        IERC20 erc20 = IERC20(_currencyAddress);
        uint256 balanceBefore = erc20.balanceOf(address(this));
        erc20.safeTransferFrom(msg.sender, address(this), _amount);
        uint256 balanceAfter = erc20.balanceOf(address(this));
        require(
            balanceAfter.sub(balanceBefore) == _amount,
            "not enough tokens transfered"
        );
    }
    /// @notice Refunds an address the designated amount.
    /// @dev Return if amount being refunded is zero.
    /// @dev Forwards to payment contract if eth is being refunded.
    /// @param _currencyAddress Address of currency being refunded.
    /// @param _amount Amount being refunded.
    /// @param _marketplaceFee Marketplace Fee (percentage) paid by _recipient.
    /// @param _recipient Address amount is being refunded to.
    function _refund(
        address _currencyAddress,
        uint256 _amount,
        uint256 _marketplaceFee,
        address _recipient
    ) internal {
        if (_amount == 0) {
            return;
        }
        uint256 requiredAmount = _amount.add(
            _amount.mul(_marketplaceFee).div(100)
        );
        if (_currencyAddress == address(0)) {
            (bool success, bytes memory data) = address(payments).call{
                value: requiredAmount
            }(
                abi.encodeWithSignature(
                    "refund(address,uint256)",
                    _recipient,
                    requiredAmount
                )
            );
            require(success, string(data));
            return;
        }
        IERC20 erc20 = IERC20(_currencyAddress);
        erc20.safeTransfer(_recipient, requiredAmount);
    }
    /// @notice Sends a payout to all the necessary parties.
    /// @dev Sends payments to the network, royalty if applicable, and splits for the rest.
    /// @dev Forwards payments to the payment contract if payout is happening in eth.
    /// @dev Total amount of ratios should be 100 and is relative to the total ratio left.
    /// @param _originContract Contract address of asset triggering a payout.
    /// @param _tokenId Token Id of the asset.
    /// @param _currencyAddress Address of currency being paid out.
    /// @param _amount Total amount to be paid out.
    /// @param _seller Address of the person selling the asset.
    /// @param _splitAddrs Addresses that funds need to be split against.
    /// @param _splitRatios Ratios for split pertaining to each address.
    function _payout(
        address _originContract,
        uint256 _tokenId,
        address _currencyAddress,
        uint256 _amount,
        address _seller,
        address payable[] memory _splitAddrs,
        uint8[] memory _splitRatios
    ) internal {
        require(
            _splitAddrs.length == _splitRatios.length,
            "Number of split addresses and ratios must be equal."
        );
        /*
        The overall flow for payouts is:
            1. Payout marketplace fee
            2. Primary/Secondary Payouts
                a. Primary -> If space sale, query space operator registry for platform comission and payout
                              Else query marketplace setting for primary sale comission and payout
                b. Secondary -> Query global royalty registry for recipients and amounts and payout
            3. Calculate the amount for each _splitAddr based on remaining amount and payout
         */
        uint256 remainingAmount = _amount;
        // Marketplace fee
        uint256 marketplaceFee = marketplaceSettings.calculateMarketplaceFee(
            _amount
        );
        address payable[] memory mktFeeRecip = new address payable[](1);
        mktFeeRecip[0] = payable(networkBeneficiary);
        uint256[] memory mktFee = new uint256[](1);
        mktFee[0] = marketplaceFee;
        _performPayouts(_currencyAddress, marketplaceFee, mktFeeRecip, mktFee);
        if (
            !marketplaceSettings.hasERC721TokenSold(_originContract, _tokenId)
        ) {
            uint256[] memory platformFee = new uint256[](1);
            if (spaceOperatorRegistry.isApprovedSpaceOperator(_seller)) {
                uint256 platformCommission = spaceOperatorRegistry
                    .getPlatformCommission(_seller);
                remainingAmount = remainingAmount.sub(
                    _amount.mul(platformCommission).div(100)
                );
                platformFee[0] = _amount.mul(platformCommission).div(100);
                _performPayouts(
                    _currencyAddress,
                    platformFee[0],
                    mktFeeRecip,
                    platformFee
                );
            } else {
                uint256 platformCommission = marketplaceSettings
                    .getERC721ContractPrimarySaleFeePercentage(_originContract);
                remainingAmount = remainingAmount.sub(
                    _amount.mul(platformCommission).div(100)
                );
                platformFee[0] = _amount.mul(platformCommission).div(100);
                _performPayouts(
                    _currencyAddress,
                    platformFee[0],
                    mktFeeRecip,
                    platformFee
                );
            }
        } else {
            (
                address payable[] memory receivers,
                uint256[] memory royalties
            ) = royaltyEngine.getRoyalty(_originContract, _tokenId, _amount);
            uint256 totalRoyalties = 0;
            for (uint256 i = 0; i < royalties.length; i++) {
                totalRoyalties = totalRoyalties.add(royalties[i]);
            }
            remainingAmount = remainingAmount.sub(totalRoyalties);
            _performPayouts(
                _currencyAddress,
                totalRoyalties,
                receivers,
                royalties
            );
        }
        uint256[] memory remainingAmts = new uint256[](_splitAddrs.length);
        uint256 totalSplit = 0;
        for (uint256 i = 0; i < _splitAddrs.length; i++) {
            remainingAmts[i] = remainingAmount.mul(_splitRatios[i]).div(100);
            totalSplit = totalSplit.add(
                remainingAmount.mul(_splitRatios[i]).div(100)
            );
        }
        _performPayouts(
            _currencyAddress,
            totalSplit,
            _splitAddrs,
            remainingAmts
        );
    }
    function _performPayouts(
        address _currencyAddress,
        uint256 _amount,
        address payable[] memory _recipients,
        uint256[] memory _amounts
    ) internal {
        if (_currencyAddress == address(0)) {
            (bool success, bytes memory data) = address(payments).call{
                value: _amount
            }(
                abi.encodeWithSelector(
                    IPayments.payout.selector,
                    _recipients,
                    _amounts
                )
            );
            require(success, string(data));
        } else {
            IERC20 erc20 = IERC20(_currencyAddress);
            for (uint256 i = 0; i < _recipients.length; i++) {
                erc20.safeTransfer(_recipients[i], _amounts[i]);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";
/*
 * @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 GSN 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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;
import "../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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);
    }
    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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
import "../../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;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }
    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.
        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "../../marketplace/IMarketplaceSettings.sol";
import "../../royalty/creator/IERC721CreatorRoyalty.sol";
import "../../payments/IPayments.sol";
import "../../registry/spaces/ISpaceOperatorRegistry.sol";
import "../../registry/token/IApprovedTokenRegistry.sol";
import "../../royalty/creator/IRoyaltyEngine.sol";
/// @author koloz
/// @title SuperRareBazaar Storage Contract
/// @dev STORAGE CAN ONLY BE APPENDED NOT INSERTED OR MODIFIED
contract SuperRareBazaarStorage {
    /////////////////////////////////////////////////////////////////////////
    // Constants
    /////////////////////////////////////////////////////////////////////////
    // Auction Types
    bytes32 public constant COLDIE_AUCTION = "COLDIE_AUCTION";
    bytes32 public constant SCHEDULED_AUCTION = "SCHEDULED_AUCTION";
    bytes32 public constant NO_AUCTION = bytes32(0);
    /////////////////////////////////////////////////////////////////////////
    // Structs
    /////////////////////////////////////////////////////////////////////////
    // The Offer truct for a given token:
    // buyer - address of person making the offer
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // amount - offer in wei/full erc20 value
    // marketplaceFee - the amount that is taken by the network on offer acceptance.
    struct Offer {
        address payable buyer;
        uint256 amount;
        uint256 timestamp;
        uint8 marketplaceFee;
        bool convertible;
    }
    // The Sale Price struct for a given token:
    // seller - address of the person selling the token
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // amount - offer in wei/full erc20 value
    struct SalePrice {
        address payable seller;
        address currencyAddress;
        uint256 amount;
        address payable[] splitRecipients;
        uint8[] splitRatios;
    }
    // Structure of an Auction:
    // auctionCreator - creator of the auction
    // creationBlock - time that the auction was created/configured
    // startingBlock - time that the auction starts on
    // lengthOfAuction - how long the auction is
    // currencyAddress - address of the erc20 token used for an offer
    //                   or the zero address for eth
    // minimumBid - min amount a bidder can bid at the start of an auction.
    // auctionType - type of auction, represented as the formatted bytes 32 string
    struct Auction {
        address payable auctionCreator;
        uint256 creationBlock;
        uint256 startingTime;
        uint256 lengthOfAuction;
        address currencyAddress;
        uint256 minimumBid;
        bytes32 auctionType;
        address payable[] splitRecipients;
        uint8[] splitRatios;
    }
    struct Bid {
        address payable bidder;
        address currencyAddress;
        uint256 amount;
        uint8 marketplaceFee;
    }
    /////////////////////////////////////////////////////////////////////////
    // Events
    /////////////////////////////////////////////////////////////////////////
    event Sold(
        address indexed _originContract,
        address indexed _buyer,
        address indexed _seller,
        address _currencyAddress,
        uint256 _amount,
        uint256 _tokenId
    );
    event SetSalePrice(
        address indexed _originContract,
        address indexed _currencyAddress,
        address _target,
        uint256 _amount,
        uint256 _tokenId,
        address payable[] _splitRecipients,
        uint8[] _splitRatios
    );
    event OfferPlaced(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _currencyAddress,
        uint256 _amount,
        uint256 _tokenId,
        bool _convertible
    );
    event AcceptOffer(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _seller,
        address _currencyAddress,
        uint256 _amount,
        uint256 _tokenId,
        address payable[] _splitAddresses,
        uint8[] _splitRatios
    );
    event CancelOffer(
        address indexed _originContract,
        address indexed _bidder,
        address indexed _currencyAddress,
        uint256 _amount,
        uint256 _tokenId
    );
    event NewAuction(
        address indexed _contractAddress,
        uint256 indexed _tokenId,
        address indexed _auctionCreator,
        address _currencyAddress,
        uint256 _startingTime,
        uint256 _minimumBid,
        uint256 _lengthOfAuction
    );
    event CancelAuction(
        address indexed _contractAddress,
        uint256 indexed _tokenId,
        address indexed _auctionCreator
    );
    event AuctionBid(
        address indexed _contractAddress,
        address indexed _bidder,
        uint256 indexed _tokenId,
        address _currencyAddress,
        uint256 _amount,
        bool _startedAuction,
        uint256 _newAuctionLength,
        address _previousBidder
    );
    event AuctionSettled(
        address indexed _contractAddress,
        address indexed _bidder,
        address _seller,
        uint256 indexed _tokenId,
        address _currencyAddress,
        uint256 _amount
    );
    /////////////////////////////////////////////////////////////////////////
    // State Variables
    /////////////////////////////////////////////////////////////////////////
    // Current marketplace settings implementation to be used
    IMarketplaceSettings public marketplaceSettings;
    // Current creator royalty implementation to be used
    IERC721CreatorRoyalty public royaltyRegistry;
    // Address of the global royalty engine being used.
    IRoyaltyEngineV1 public royaltyEngine;
    // Current SuperRareMarketplace implementation to be used
    address public superRareMarketplace;
    // Current SuperRareAuctionHouse implementation to be used
    address public superRareAuctionHouse;
    // Current SpaceOperatorRegistry implementation to be used.
    ISpaceOperatorRegistry public spaceOperatorRegistry;
    // Current ApprovedTokenRegistry implementation being used for currencies.
    IApprovedTokenRegistry public approvedTokenRegistry;
    // Current payments contract to use
    IPayments public payments;
    // Address to be used for staking registry.
    address public stakingRegistry;
    // Address of the network beneficiary
    address public networkBeneficiary;
    // A minimum increase in bid amount when out bidding someone.
    uint8 public minimumBidIncreasePercentage; // 10 = 10%
    // Maximum length that an auction can be.
    uint256 public maxAuctionLength;
    // Extension length for an auction
    uint256 public auctionLengthExtension;
    // Offer cancellation delay
    uint256 public offerCancelationDelay;
    // Mapping from contract to mapping of tokenId to mapping of target to sale price.
    mapping(address => mapping(uint256 => mapping(address => SalePrice)))
        public tokenSalePrices;
    // Mapping from contract to mapping of tokenId to mapping of currency address to Current Offer.
    mapping(address => mapping(uint256 => mapping(address => Offer)))
        public tokenCurrentOffers;
    // Mapping from contract to mapping of tokenId to Auction.
    mapping(address => mapping(uint256 => Auction)) public tokenAuctions;
    // Mapping from contract to mapping of tokenId to Bid.
    mapping(address => mapping(uint256 => Bid)) public auctionBids;
    uint256[50] private __gap;
    /// ALL NEW STORAGE MUST COME AFTER THIS
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/**
 * @title IMarketplaceSettings Settings governing a marketplace.
 */
interface IMarketplaceSettings {
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Min and Max Values
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMaxValue() external view returns (uint256);
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMinValue() external view returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the marketplace fee percentage.
     * @return uint8 wei fee.
     */
    function getMarketplaceFeePercentage() external view returns (uint8);
    /**
     * @dev Utility function for calculating the marketplace fee for given amount of wei.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculateMarketplaceFee(uint256 _amount)
        external
        view
        returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Primary Sale Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the primary sale fee percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @return uint8 wei primary sale fee.
     */
    function getERC721ContractPrimarySaleFeePercentage(address _contractAddress)
        external
        view
        returns (uint8);
    /**
     * @dev Utility function for calculating the primary sale fee for given amount of wei
     * @param _contractAddress address ERC721Contract address.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculatePrimarySaleFee(address _contractAddress, uint256 _amount)
        external
        view
        returns (uint256);
    /**
     * @dev Check whether the ERC721 token has sold at least once.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @return bool of whether the token has sold.
     */
    function hasERC721TokenSold(address _contractAddress, uint256 _tokenId)
        external
        view
        returns (bool);
    /**
     * @dev Mark a token as sold.
     * Requirements:
     *
     * - `_contractAddress` cannot be the zero address.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @param _hasSold bool of whether the token should be marked sold or not.
     */
    function markERC721Token(
        address _contractAddress,
        uint256 _tokenId,
        bool _hasSold
    ) external;
    function setERC721ContractPrimarySaleFeePercentage(
        address _contractAddress,
        uint8 _percentage
    ) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "../../token/ERC721/IERC721TokenCreator.sol";
/**
 * @title IERC721CreatorRoyalty Token level royalty interface.
 */
interface IERC721CreatorRoyalty is IERC721TokenCreator {
    /**
     * @dev Get the royalty fee percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @return uint8 wei royalty fee.
     */
    function getERC721TokenRoyaltyPercentage(
        address _contractAddress,
        uint256 _tokenId
    ) external view returns (uint8);
    /**
     * @dev Utililty function to calculate the royalty fee for a token.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculateRoyaltyFee(
        address _contractAddress,
        uint256 _tokenId,
        uint256 _amount
    ) external view returns (uint256);
    /**
     * @dev Utililty function to set the royalty percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @param _percentage percentage for royalty
     */
    function setPercentageForSetERC721ContractRoyalty(
        address _contractAddress,
        uint8 _percentage
    ) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title IPayments
/// @notice Interface for the Payments contract used.
interface IPayments {
    function refund(address _payee, uint256 _amount) external payable;
    function payout(address[] calldata _splits, uint256[] calldata _amounts)
        external
        payable;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title ISpaceOperatorRegistry
/// @notice The interface for the SpaceOperatorRegistry
interface ISpaceOperatorRegistry {
    function getPlatformCommission(address _operator)
        external
        view
        returns (uint8);
    function setPlatformCommission(address _operator, uint8 _commission)
        external;
    function isApprovedSpaceOperator(address _operator)
        external
        view
        returns (bool);
    function setSpaceOperatorApproved(address _operator, bool _approved)
        external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
interface IApprovedTokenRegistry {
    /// @notice Returns if a token has been approved or not.
    /// @param _tokenContract Contract of token being checked.
    /// @return True if the token is allowed, false otherwise.
    function isApprovedToken(address _tokenContract)
        external
        view
        returns (bool);
    /// @notice Adds a token to the list of approved tokens.
    /// @param _tokenContract Contract of token being approved.
    function addApprovedToken(address _tokenContract) external;
    /// @notice Removes a token from the approved tokens list.
    /// @param _tokenContract Contract of token being approved.
    function removeApprovedToken(address _tokenContract) external;
    /// @notice Sets whether all token contracts should be approved.
    /// @param _allTokensApproved Bool denoting if all tokens should be approved.
    function setAllTokensApproved(bool _allTokensApproved) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author: manifold.xyz
/**
 * @dev Lookup engine interface
 */
interface IRoyaltyEngineV1 {
    /**
     * Get the royalty for a given token (address, id) and value amount.  Does not cache the bps/amounts.  Caches the spec for a given token address
     *
     * @param tokenAddress - The address of the token
     * @param tokenId      - The id of the token
     * @param value        - The value you wish to get the royalty of
     *
     * returns Two arrays of equal length, royalty recipients and the corresponding amount each recipient should get
     */
    function getRoyalty(
        address tokenAddress,
        uint256 tokenId,
        uint256 value
    )
        external
        returns (address payable[] memory recipients, uint256[] memory amounts);
    /**
     * View only version of getRoyalty
     *
     * @param tokenAddress - The address of the token
     * @param tokenId      - The id of the token
     * @param value        - The value you wish to get the royalty of
     *
     * returns Two arrays of equal length, royalty recipients and the corresponding amount each recipient should get
     */
    function getRoyaltyView(
        address tokenAddress,
        uint256 tokenId,
        uint256 value
    )
        external
        view
        returns (address payable[] memory recipients, uint256[] memory amounts);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
interface IERC721TokenCreator {
    function tokenCreator(address _contractAddress, uint256 _tokenId)
        external
        view
        returns (address payable);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;
import {IMarketplaceSettings} from "./IMarketplaceSettings.sol";
import {Ownable} from "openzeppelin-contracts/access/Ownable.sol";
import {AccessControl} from "openzeppelin-contracts/access/AccessControl.sol";
import {ITokenCreator} from "../token/ITokenCreator.sol";
import {IERC721} from "openzeppelin-contracts/token/ERC721/IERC721.sol";
import {EnumerableSet} from "openzeppelin-contracts/utils/structs/EnumerableSet.sol";
contract MarketplaceSettingsV2 is Ownable, AccessControl, IMarketplaceSettings {
    bytes32 public constant TOKEN_MARK_ROLE = keccak256("TOKEN_MARK_ROLE");
    // This is meant to be the MarketplaceSettings contract located in the V1 folder
    IMarketplaceSettings private oldMarketplaceSettings;
    // EnumerableSet library method
    using EnumerableSet for EnumerableSet.AddressSet;
    // EnumerableSet of contracts marked sold
    EnumerableSet.AddressSet private contractSold;
    uint256 private maxValue;
    uint256 private minValue;
    uint8 private marketplaceFeePercentage;
    uint8 private primarySaleFeePercentage;
    constructor(address newOwner, address oldSettings) {
        maxValue = 2**254;
        minValue = 1000;
        marketplaceFeePercentage = 3;
        primarySaleFeePercentage = 15;
        require(
            newOwner != address(0),
            "constructor::New owner address cannot be null"
        );
        require(
            oldSettings != address(0),
            "constructor::Old Marketplace Settings address cannot be null"
        );
        _setupRole(AccessControl.DEFAULT_ADMIN_ROLE, newOwner);
        _setupRole(TOKEN_MARK_ROLE, newOwner);
        transferOwnership(newOwner);
        oldMarketplaceSettings = IMarketplaceSettings(oldSettings);
    }
    function grantMarketplaceAccess(address _account) external {
        require(
            hasRole(AccessControl.DEFAULT_ADMIN_ROLE, _msgSender()),
            "grantMarketplaceAccess::Must be admin to call method"
        );
        grantRole(TOKEN_MARK_ROLE, _account);
    }
    function getMarketplaceMaxValue() external view override returns (uint256) {
        return maxValue;
    }
    function setPrimarySaleFeePercentage(uint8 _primarySaleFeePercentage)
        external
        onlyOwner
    {
        primarySaleFeePercentage = _primarySaleFeePercentage;
    }
    function setMarketplaceMaxValue(uint256 _maxValue) external onlyOwner {
        maxValue = _maxValue;
    }
    function getMarketplaceMinValue() external view override returns (uint256) {
        return minValue;
    }
    function setMarketplaceMinValue(uint256 _minValue) external onlyOwner {
        minValue = _minValue;
    }
    function getMarketplaceFeePercentage()
        external
        view
        override
        returns (uint8)
    {
        return marketplaceFeePercentage;
    }
    function setMarketplaceFeePercentage(uint8 _percentage) external onlyOwner {
        require(
            _percentage <= 100,
            "setMarketplaceFeePercentage::_percentage must be <= 100"
        );
        marketplaceFeePercentage = _percentage;
    }
    function calculateMarketplaceFee(uint256 _amount)
        external
        view
        override
        returns (uint256)
    {
        return (_amount * marketplaceFeePercentage) / 100;
    }
    function getERC721ContractPrimarySaleFeePercentage(address)
        external
        view
        override
        returns (uint8)
    {
        return primarySaleFeePercentage;
    }
    function setERC721ContractPrimarySaleFeePercentage(
        address _contractAddress,
        uint8 _percentage
    ) external override {}
    function calculatePrimarySaleFee(address, uint256 _amount)
        external
        view
        override
        returns (uint256)
    {
        return (_amount * primarySaleFeePercentage) / 100;
    }
    function hasERC721TokenSold(address _contractAddress, uint256 _tokenId)
        external
        view
        override
        returns (bool)
    {
        bool contractHasSold = contractSold.contains(_contractAddress);
        if (contractHasSold) return true;
        return
            oldMarketplaceSettings.hasERC721TokenSold(
                _contractAddress,
                _tokenId
            );
    }
    function markERC721Token(
        address _contractAddress,
        uint256 _tokenId,
        bool _hasSold
    ) public override {
        require(
            hasRole(TOKEN_MARK_ROLE, msg.sender),
            "markERC721Token::Must have TOKEN_MARK_ROLE role to call method"
        );
        oldMarketplaceSettings.markERC721Token(
            _contractAddress,
            _tokenId,
            _hasSold
        );
    }
    function markTokensAsSold(
        address _originContract,
        uint256[] calldata _tokenIds
    ) external {
        require(
            hasRole(TOKEN_MARK_ROLE, msg.sender),
            "markERC721Token::Must have TOKEN_MARK_ROLE role to call method"
        );
        // limit to batches of 2000
        require(
            _tokenIds.length <= 2000,
            "markTokensAsSold::Attempted to mark more than 2000 tokens as sold"
        );
        // Mark provided tokens as sold.
        for (uint256 i = 0; i < _tokenIds.length; i++) {
            markERC721Token(_originContract, _tokenIds[i], true);
        }
    }
    function markContractAsSold(address _contractAddress)
        external
        returns (bool)
    {
        require(
            hasRole(TOKEN_MARK_ROLE, msg.sender),
            "markContract::Must have TOKEN_MARK_ROLE role to call method"
        );
        // Prevents contract address from being marked multiple times
        require(
            !contractSold.contains(_contractAddress),
            "markContract::Contract already marked as sold"
        );
        // Adds contract address to set
        return contractSold.add(_contractAddress);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;
/**
 * @title IMarketplaceSettings Settings governing a marketplace.
 */
interface IMarketplaceSettings {
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Min and Max Values
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMaxValue() external view returns (uint256);
    /**
     * @dev Get the max value to be used with the marketplace.
     * @return uint256 wei value.
     */
    function getMarketplaceMinValue() external view returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Marketplace Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the marketplace fee percentage.
     * @return uint8 wei fee.
     */
    function getMarketplaceFeePercentage() external view returns (uint8);
    /**
     * @dev Utility function for calculating the marketplace fee for given amount of wei.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculateMarketplaceFee(uint256 _amount)
        external
        view
        returns (uint256);
    /////////////////////////////////////////////////////////////////////////
    // Primary Sale Fee
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Get the primary sale fee percentage for a specific ERC721 contract.
     * @param _contractAddress address ERC721Contract address.
     * @return uint8 wei primary sale fee.
     */
    function getERC721ContractPrimarySaleFeePercentage(address _contractAddress)
        external
        view
        returns (uint8);
    /**
     * @dev Utility function for calculating the primary sale fee for given amount of wei
     * @param _contractAddress address ERC721Contract address.
     * @param _amount uint256 wei amount.
     * @return uint256 wei fee.
     */
    function calculatePrimarySaleFee(address _contractAddress, uint256 _amount)
        external
        view
        returns (uint256);
    /**
     * @dev Check whether the ERC721 token has sold at least once.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @return bool of whether the token has sold.
     */
    function hasERC721TokenSold(address _contractAddress, uint256 _tokenId)
        external
        view
        returns (bool);
    /**
     * @dev Mark a token as sold.
     * Requirements:
     *
     * - `_contractAddress` cannot be the zero address.
     * @param _contractAddress address ERC721Contract address.
     * @param _tokenId uint256 token ID.
     * @param _hasSold bool of whether the token should be marked sold or not.
     */
    function markERC721Token(
        address _contractAddress,
        uint256 _tokenId,
        bool _hasSold
    ) external;
    function setERC721ContractPrimarySaleFeePercentage(
        address _contractAddress,
        uint8 _percentage
    ) external;
}
// 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);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";
/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }
    mapping(bytes32 => RoleData) private _roles;
    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
    }
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }
    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }
    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(uint160(account), 20),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");
        _revokeRole(role, account);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }
    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }
    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }
    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;
interface ITokenCreator {
    // bytes4(keccak256(tokenCreator(uint256))) == 0x40c1a064
    function tokenCreator(uint256 _tokenId)
        external
        view
        returns (address payable);
}
// 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);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            if (lastIndex != toDeleteIndex) {
                bytes32 lastValue = set._values[lastIndex];
                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastValue;
                // Update the index for the moved value
                set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
            }
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        return _values(set._inner);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;
        assembly {
            result := store
        }
        return result;
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;
        assembly {
            result := store
        }
        return result;
    }
}
// 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;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);
    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);
    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;
    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}
// 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);
    }
}
// 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;
    }
}
// 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);
}

// contracts/token/ERC721/sovereign/SovereignNFT.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
pragma experimental ABIEncoderV2;
import "@openzeppelin/contracts-upgradeable-0.7.2/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/token/ERC721/ERC721BurnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/introspection/ERC165Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/utils/CountersUpgradeable.sol";
import "../IERC721Creator.sol";
import "../../../royalty/ERC2981Upgradeable.sol";
contract SovereignNFT is
    OwnableUpgradeable,
    ERC165Upgradeable,
    ERC721Upgradeable,
    IERC721Creator,
    ERC721BurnableUpgradeable,
    ERC2981Upgradeable
{
    using SafeMathUpgradeable for uint256;
    using StringsUpgradeable for uint256;
    using CountersUpgradeable for CountersUpgradeable.Counter;
    struct MintBatch {
        uint256 startTokenId;
        uint256 endTokenId;
        string baseURI;
    }
    bool public disabled;
    // Mapping from token ID to the creator's address
    mapping(uint256 => address) private tokenCreators;
    // Mapping from tokenId to if it was burned or not (for batch minting)
    mapping(uint256 => bool) private tokensBurned;
    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;
    // Counter to keep track of the current token id.
    CountersUpgradeable.Counter private tokenIdCounter;
    MintBatch[] private mintBatches;
    // Default royalty percentage
    uint256 public defaultRoyaltyPercentage;
    event ContractDisabled(address indexed user);
    event ConsecutiveTransfer(
        uint256 indexed fromTokenId,
        uint256 toTokenId,
        address indexed fromAddress,
        address indexed toAddress
    );
    function init(
        string calldata _name,
        string calldata _symbol,
        address _creator
    ) public initializer {
        require(_creator != address(0));
        defaultRoyaltyPercentage = 10;
        disabled = false;
        __Ownable_init();
        __ERC721_init(_name, _symbol);
        __ERC165_init();
        __ERC2981__init();
        _setDefaultRoyaltyReceiver(_creator);
        _registerInterface(calcIERC721CreatorInterfaceId());
        super.transferOwnership(_creator);
    }
    modifier onlyTokenOwner(uint256 _tokenId) {
        require(ownerOf(_tokenId) == msg.sender, "Must be owner of token.");
        _;
    }
    modifier ifNotDisabled() {
        require(!disabled, "Contract must not be disabled.");
        _;
    }
    function batchMint(string calldata _baseURI, uint256 _numberOfTokens)
        public
        onlyOwner
        ifNotDisabled
    {
        uint256 startTokenId = tokenIdCounter.current() + 1;
        uint256 endTokenId = startTokenId + _numberOfTokens - 1;
        tokenIdCounter = CountersUpgradeable.Counter(endTokenId);
        mintBatches.push(MintBatch(startTokenId, endTokenId, _baseURI));
        emit ConsecutiveTransfer(startTokenId, endTokenId, address(0), owner());
    }
    function addNewToken(string memory _uri) public onlyOwner ifNotDisabled {
        _createToken(
            _uri,
            msg.sender,
            msg.sender,
            defaultRoyaltyPercentage,
            msg.sender
        );
    }
    function mintTo(
        string calldata _uri,
        address _receiver,
        address _royaltyReceiver
    ) external onlyOwner ifNotDisabled {
        _createToken(
            _uri,
            msg.sender,
            _receiver,
            defaultRoyaltyPercentage,
            _royaltyReceiver
        );
    }
    function renounceOwnership() public view override onlyOwner {
        revert("unsupported");
    }
    function transferOwnership(address) public view override onlyOwner {
        revert("unsupported");
    }
    function deleteToken(uint256 _tokenId) public onlyTokenOwner(_tokenId) {
        burn(_tokenId);
    }
    function burn(uint256 _tokenId) public virtual override {
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        tokensBurned[_tokenId] = true;
        if (wasBatchMinted && !ERC721Upgradeable._exists(_tokenId)) {
            return;
        }
        ERC721BurnableUpgradeable.burn(_tokenId);
    }
    function tokenCreator(uint256)
        public
        view
        override
        returns (address payable)
    {
        return payable(owner());
    }
    function disableContract() public onlyOwner {
        disabled = true;
        emit ContractDisabled(msg.sender);
    }
    function setDefaultRoyaltyReceiver(address _receiver) external onlyOwner {
        _setDefaultRoyaltyReceiver(_receiver);
    }
    function setRoyaltyReceiverForToken(address _receiver, uint256 _tokenId)
        external
        onlyOwner
    {
        royaltyReceivers[_tokenId] = _receiver;
    }
    function _setTokenCreator(uint256 _tokenId, address _creator) internal {
        tokenCreators[_tokenId] = _creator;
    }
    function _createToken(
        string memory _uri,
        address _creator,
        address _to,
        uint256 _royaltyPercentage,
        address _royaltyReceiver
    ) internal returns (uint256) {
        tokenIdCounter.increment();
        uint256 tokenId = tokenIdCounter.current();
        _safeMint(_to, tokenId);
        _setTokenURI(tokenId, _uri);
        _setTokenCreator(tokenId, _creator);
        _setRoyaltyPercentage(tokenId, _royaltyPercentage);
        _setRoyaltyReceiver(tokenId, _royaltyReceiver);
        return tokenId;
    }
    ///////////////////////////////////////////////
    // Overriding Methods to support batch mints
    ///////////////////////////////////////////////
    function tokenURI(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (string memory)
    {
        (bool wasBatchMinted, , string memory baseTokenUri) = _batchMintInfo(
            _tokenId
        );
        if (!wasBatchMinted) {
            return super.tokenURI(_tokenId);
        } else {
            return
                string(
                    abi.encodePacked(
                        baseTokenUri,
                        "/",
                        _tokenId.toString(),
                        ".json"
                    )
                );
        }
    }
    function ownerOf(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (address)
    {
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        if (!wasBatchMinted) {
            return ERC721Upgradeable.ownerOf(_tokenId);
        } else if (tokensBurned[_tokenId]) {
            return ERC721Upgradeable.ownerOf(_tokenId);
        } else {
            if (!ERC721Upgradeable._exists(_tokenId)) {
                return owner();
            } else {
                return ERC721Upgradeable.ownerOf(_tokenId);
            }
        }
    }
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = 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);
    }
    function _isApprovedOrOwner(address _spender, uint256 _tokenId)
        internal
        view
        virtual
        override
        returns (bool)
    {
        address owner = ownerOf(_tokenId);
        return (_spender == owner ||
            getApproved(_tokenId) == _spender ||
            isApprovedForAll(owner, _spender));
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal override {
        _tokenApprovals[tokenId] = to;
        emit Approval(ownerOf(tokenId), to, tokenId); // internal owner
    }
    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (address)
    {
        address receiver = royaltyReceivers[_tokenId];
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        bool exists = (wasBatchMinted || receiver != address(0)) &&
            !tokensBurned[_tokenId];
        require(exists, "ERC721: approved query for nonexistent token");
        return _tokenApprovals[_tokenId];
    }
    function _transfer(
        address _from,
        address _to,
        uint256 _tokenId
    ) internal virtual override {
        require(_tokenId != 0);
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        if (
            wasBatchMinted &&
            !ERC721Upgradeable._exists(_tokenId) &&
            !tokensBurned[_tokenId]
        ) {
            _mint(_from, _tokenId);
        }
        ERC721Upgradeable._transfer(_from, _to, _tokenId);
    }
    function totalSupply() public view virtual override returns (uint256) {
        return tokenIdCounter.current();
    }
    function _batchMintInfo(uint256 _tokenId)
        internal
        view
        returns (
            bool _wasBatchMinted,
            uint256 _batchIndex,
            string memory _baseTokenUri
        )
    {
        for (uint256 i = 0; i < mintBatches.length; i++) {
            if (
                _tokenId >= mintBatches[i].startTokenId &&
                _tokenId <= mintBatches[i].endTokenId
            ) {
                return (true, i, mintBatches[i].baseURI);
            }
        }
        return (false, 0, "");
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../utils/ContextUpgradeable.sol";
import "./IERC721Upgradeable.sol";
import "./IERC721MetadataUpgradeable.sol";
import "./IERC721EnumerableUpgradeable.sol";
import "./IERC721ReceiverUpgradeable.sol";
import "../../introspection/ERC165Upgradeable.sol";
import "../../math/SafeMathUpgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/EnumerableSetUpgradeable.sol";
import "../../utils/EnumerableMapUpgradeable.sol";
import "../../utils/StringsUpgradeable.sol";
import "../../proxy/Initializable.sol";
/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev see https://eips.ethereum.org/EIPS/eip-721
 */
contract ERC721Upgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721Upgradeable, IERC721MetadataUpgradeable, IERC721EnumerableUpgradeable {
    using SafeMathUpgradeable for uint256;
    using AddressUpgradeable for address;
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.UintSet;
    using EnumerableMapUpgradeable for EnumerableMapUpgradeable.UintToAddressMap;
    using StringsUpgradeable for uint256;
    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
    // Mapping from holder address to their (enumerable) set of owned tokens
    mapping (address => EnumerableSetUpgradeable.UintSet) private _holderTokens;
    // Enumerable mapping from token ids to their owners
    EnumerableMapUpgradeable.UintToAddressMap private _tokenOwners;
    // 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;
    // Token name
    string private _name;
    // Token symbol
    string private _symbol;
    // Optional mapping for token URIs
    mapping (uint256 => string) private _tokenURIs;
    // Base URI
    string private _baseURI;
    /*
     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231
     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
     *
     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
     *        0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
     */
    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
    /*
     *     bytes4(keccak256('name()')) == 0x06fdde03
     *     bytes4(keccak256('symbol()')) == 0x95d89b41
     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
     *
     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
     */
    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
    /*
     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd
     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
     *
     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
     */
    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    function __ERC721_init(string memory name_, string memory symbol_) internal initializer {
        __Context_init_unchained();
        __ERC165_init_unchained();
        __ERC721_init_unchained(name_, symbol_);
    }
    function __ERC721_init_unchained(string memory name_, string memory symbol_) internal initializer {
        _name = name_;
        _symbol = symbol_;
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_INTERFACE_ID_ERC721);
        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
    }
    /**
     * @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 _holderTokens[owner].length();
    }
    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
    }
    /**
     * @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 _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));
        }
        // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
        return string(abi.encodePacked(base, tokenId.toString()));
    }
    /**
    * @dev Returns the base URI set via {_setBaseURI}. This will be
    * automatically added as a prefix in {tokenURI} to each token's URI, or
    * to the token ID if no specific URI is set for that token ID.
    */
    function baseURI() public view virtual returns (string memory) {
        return _baseURI;
    }
    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        return _holderTokens[owner].at(index);
    }
    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
        return _tokenOwners.length();
    }
    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        (uint256 tokenId, ) = _tokenOwners.at(index);
        return tokenId;
    }
    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721Upgradeable.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");
        require(_msgSender() == owner || ERC721Upgradeable.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 {
        require(operator != _msgSender(), "ERC721: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_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 _tokenOwners.contains(tokenId);
    }
    /**
     * @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 = ERC721Upgradeable.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || ERC721Upgradeable.isApprovedForAll(owner, spender));
    }
    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     d*
     * - `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);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(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 = ERC721Upgradeable.ownerOf(tokenId); // internal owner
        _beforeTokenTransfer(owner, address(0), tokenId);
        // Clear approvals
        _approve(address(0), tokenId);
        // Clear metadata (if any)
        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
        _holderTokens[owner].remove(tokenId);
        _tokenOwners.remove(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(ERC721Upgradeable.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); // internal 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);
        _holderTokens[from].remove(tokenId);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(tokenId, to);
        emit Transfer(from, to, 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), "ERC721Metadata: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }
    /**
     * @dev Internal function to set the base URI for all token IDs. It is
     * automatically added as a prefix to the value returned in {tokenURI},
     * or to the token ID if {tokenURI} is empty.
     */
    function _setBaseURI(string memory baseURI_) internal virtual {
        _baseURI = baseURI_;
    }
    /**
     * @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()) {
            return true;
        }
        bytes memory returndata = to.functionCall(abi.encodeWithSelector(
            IERC721ReceiverUpgradeable(to).onERC721Received.selector,
            _msgSender(),
            from,
            tokenId,
            _data
        ), "ERC721: transfer to non ERC721Receiver implementer");
        bytes4 retval = abi.decode(returndata, (bytes4));
        return (retval == _ERC721_RECEIVED);
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721Upgradeable.ownerOf(tokenId), to, tokenId); // internal owner
    }
    /**
     * @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 { }
    uint256[41] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../utils/ContextUpgradeable.sol";
import "./ERC721Upgradeable.sol";
import "../../proxy/Initializable.sol";
/**
 * @title ERC721 Burnable Token
 * @dev ERC721 Token that can be irreversibly burned (destroyed).
 */
abstract contract ERC721BurnableUpgradeable is Initializable, ContextUpgradeable, ERC721Upgradeable {
    function __ERC721Burnable_init() internal initializer {
        __Context_init_unchained();
        __ERC165_init_unchained();
        __ERC721Burnable_init_unchained();
    }
    function __ERC721Burnable_init_unchained() internal initializer {
    }
    /**
     * @dev Burns `tokenId`. See {ERC721-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) public virtual {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
        _burn(tokenId);
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC165Upgradeable.sol";
import "../proxy/Initializable.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts may inherit from this and call {_registerInterface} to declare
 * their support of an interface.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
    /**
     * @dev Mapping of interface ids to whether or not it's supported.
     */
    mapping(bytes4 => bool) private _supportedInterfaces;
    function __ERC165_init() internal initializer {
        __ERC165_init_unchained();
    }
    function __ERC165_init_unchained() internal initializer {
        // Derived contracts need only register support for their own interfaces,
        // we register support for ERC165 itself here
        _registerInterface(_INTERFACE_ID_ERC165);
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     *
     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return _supportedInterfaces[interfaceId];
    }
    /**
     * @dev Registers the contract as an implementer of the interface defined by
     * `interfaceId`. Support of the actual ERC165 interface is automatic and
     * registering its interface id is not required.
     *
     * See {IERC165-supportsInterface}.
     *
     * Requirements:
     *
     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
     */
    function _registerInterface(bytes4 interfaceId) internal virtual {
        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
        _supportedInterfaces[interfaceId] = true;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }
    function __Ownable_init_unchained() internal initializer {
        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;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../math/SafeMathUpgradeable.sol";
/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath}
 * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
 * directly accessed.
 */
library CountersUpgradeable {
    using SafeMathUpgradeable for uint256;
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }
    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }
    function increment(Counter storage counter) internal {
        // The {SafeMath} overflow check can be skipped here, see the comment at the top
        counter._value += 1;
    }
    function decrement(Counter storage counter) internal {
        counter._value = counter._value.sub(1);
    }
}
// contracts/token/ERC721/IERC721Creator.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/**
 * @title IERC721 Non-Fungible Token Creator basic interface
 */
abstract contract IERC721Creator {
    /**
     * @dev Gets the creator of the token
     * @param _tokenId uint256 ID of the token
     * @return address of the creator
     */
    function tokenCreator(uint256 _tokenId)
        public
        view
        virtual
        returns (address payable);
    function calcIERC721CreatorInterfaceId() public pure returns (bytes4) {
        return this.tokenCreator.selector;
    }
}
// contracts/royalty/ERC2981.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-upgradeable-0.7.2/introspection/ERC165Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/math/SafeMathUpgradeable.sol";
import "./IERC2981.sol";
abstract contract ERC2981Upgradeable is IERC2981, ERC165Upgradeable {
    using SafeMathUpgradeable for uint256;
    // bytes4(keccak256("royaltyInfo(uint256,uint256)")) == 0x2a55205a
    bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
    address public defaultRoyaltyReceiver;
    mapping(uint256 => address) royaltyReceivers;
    mapping(uint256 => uint256) royaltyPercentages;
    constructor() {}
    function __ERC2981__init() internal initializer {
        __ERC165_init();
        _registerInterface(_INTERFACE_ID_ERC2981);
    }
    function royaltyInfo(uint256 _tokenId, uint256 _salePrice)
        public
        view
        virtual
        override
        returns (address receiver, uint256 royaltyAmount)
    {
        receiver = royaltyReceivers[_tokenId] != address(0)
            ? royaltyReceivers[_tokenId]
            : defaultRoyaltyReceiver;
        royaltyAmount = _salePrice.mul(royaltyPercentages[_tokenId]).div(100);
    }
    function _setDefaultRoyaltyReceiver(address _receiver) internal {
        defaultRoyaltyReceiver = _receiver;
    }
    function _setRoyaltyReceiver(uint256 _tokenId, address _newReceiver)
        internal
    {
        royaltyReceivers[_tokenId] = _newReceiver;
    }
    function _setRoyaltyPercentage(uint256 _tokenId, uint256 _percentage)
        internal
    {
        royaltyPercentages[_tokenId] = _percentage;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";
/*
 * @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 GSN 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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../introspection/IERC165Upgradeable.sol";
/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721Upgradeable is IERC165Upgradeable {
    /**
     * @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;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721Upgradeable.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721MetadataUpgradeable is IERC721Upgradeable {
    /**
     * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721Upgradeable.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721EnumerableUpgradeable is IERC721Upgradeable {
    /**
     * @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);
    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721ReceiverUpgradeable {
    /**
     * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMathUpgradeable {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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);
    }
    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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) { // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            bytes32 lastvalue = set._values[lastIndex];
            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        require(set._values.length > index, "EnumerableSet: index out of bounds");
        return set._values[index];
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing an enumerable variant of Solidity's
 * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
 * type.
 *
 * Maps have the following properties:
 *
 * - Entries are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Entries are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableMap for EnumerableMap.UintToAddressMap;
 *
 *     // Declare a set state variable
 *     EnumerableMap.UintToAddressMap private myMap;
 * }
 * ```
 *
 * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
 * supported.
 */
library EnumerableMapUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Map type with
    // bytes32 keys and values.
    // The Map implementation uses private functions, and user-facing
    // implementations (such as Uint256ToAddressMap) are just wrappers around
    // the underlying Map.
    // This means that we can only create new EnumerableMaps for types that fit
    // in bytes32.
    struct MapEntry {
        bytes32 _key;
        bytes32 _value;
    }
    struct Map {
        // Storage of map keys and values
        MapEntry[] _entries;
        // Position of the entry defined by a key in the `entries` array, plus 1
        // because index 0 means a key is not in the map.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) { // Equivalent to !contains(map, key)
            map._entries.push(MapEntry({ _key: key, _value: value }));
            // The entry is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            map._indexes[key] = map._entries.length;
            return true;
        } else {
            map._entries[keyIndex - 1]._value = value;
            return false;
        }
    }
    /**
     * @dev Removes a key-value pair from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function _remove(Map storage map, bytes32 key) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex != 0) { // Equivalent to contains(map, key)
            // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one
            // in the array, and then remove the last entry (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = keyIndex - 1;
            uint256 lastIndex = map._entries.length - 1;
            // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            MapEntry storage lastEntry = map._entries[lastIndex];
            // Move the last entry to the index where the entry to delete is
            map._entries[toDeleteIndex] = lastEntry;
            // Update the index for the moved entry
            map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved entry was stored
            map._entries.pop();
            // Delete the index for the deleted slot
            delete map._indexes[key];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function _contains(Map storage map, bytes32 key) private view returns (bool) {
        return map._indexes[key] != 0;
    }
    /**
     * @dev Returns the number of key-value pairs in the map. O(1).
     */
    function _length(Map storage map) private view returns (uint256) {
        return map._entries.length;
    }
   /**
    * @dev Returns the key-value pair stored at position `index` in the map. O(1).
    *
    * Note that there are no guarantees on the ordering of entries inside the
    * array, and it may change when more entries are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {
        require(map._entries.length > index, "EnumerableMap: index out of bounds");
        MapEntry storage entry = map._entries[index];
        return (entry._key, entry._value);
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     */
    function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) return (false, 0); // Equivalent to contains(map, key)
        return (true, map._entries[keyIndex - 1]._value); // All indexes are 1-based
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function _get(Map storage map, bytes32 key) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, "EnumerableMap: nonexistent key"); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    /**
     * @dev Same as {_get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {_tryGet}.
     */
    function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    // UintToAddressMap
    struct UintToAddressMap {
        Map _inner;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {
        return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
        return _remove(map._inner, bytes32(key));
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
        return _contains(map._inner, bytes32(key));
    }
    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToAddressMap storage map) internal view returns (uint256) {
        return _length(map._inner);
    }
   /**
    * @dev Returns the element stored at position `index` in the set. O(1).
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
        (bytes32 key, bytes32 value) = _at(map._inner, index);
        return (uint256(key), address(uint160(uint256(value))));
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     *
     * _Available since v3.4._
     */
    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));
        return (success, address(uint160(uint256(value))));
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key)))));
    }
    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev String operations.
 */
library StringsUpgradeable {
    /**
     * @dev Converts a `uint256` to its ASCII `string` 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);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = bytes1(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;
import "../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @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 IERC165Upgradeable {
    /**
     * @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);
}
// contracts/royalty/IERC2981.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @dev Interface for the NFT Royalty Standard
interface IERC2981 {
    /// 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);
}

// contracts/token/ERC721/sovereign/SovereignNFT.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
pragma experimental ABIEncoderV2;
import "@openzeppelin/contracts-upgradeable-0.7.2/token/ERC721/ERC721Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/token/ERC721/ERC721BurnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/introspection/ERC165Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/utils/CountersUpgradeable.sol";
import "../IERC721Creator.sol";
import "../../../royalty/ERC2981Upgradeable.sol";
contract SovereignNFT is
    OwnableUpgradeable,
    ERC165Upgradeable,
    ERC721Upgradeable,
    IERC721Creator,
    ERC721BurnableUpgradeable,
    ERC2981Upgradeable
{
    using SafeMathUpgradeable for uint256;
    using StringsUpgradeable for uint256;
    using CountersUpgradeable for CountersUpgradeable.Counter;
    struct MintBatch {
        uint256 startTokenId;
        uint256 endTokenId;
        string baseURI;
    }
    bool public disabled;
    // Mapping from token ID to the creator's address
    mapping(uint256 => address) private tokenCreators;
    // Mapping from tokenId to if it was burned or not (for batch minting)
    mapping(uint256 => bool) private tokensBurned;
    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;
    // Counter to keep track of the current token id.
    CountersUpgradeable.Counter private tokenIdCounter;
    MintBatch[] private mintBatches;
    // Default royalty percentage
    uint256 public defaultRoyaltyPercentage;
    event ContractDisabled(address indexed user);
    event ConsecutiveTransfer(
        uint256 indexed fromTokenId,
        uint256 toTokenId,
        address indexed fromAddress,
        address indexed toAddress
    );
    function init(
        string calldata _name,
        string calldata _symbol,
        address _creator
    ) public initializer {
        require(_creator != address(0));
        defaultRoyaltyPercentage = 10;
        disabled = false;
        __Ownable_init();
        __ERC721_init(_name, _symbol);
        __ERC165_init();
        __ERC2981__init();
        _setDefaultRoyaltyReceiver(_creator);
        _registerInterface(calcIERC721CreatorInterfaceId());
        super.transferOwnership(_creator);
    }
    modifier onlyTokenOwner(uint256 _tokenId) {
        require(ownerOf(_tokenId) == msg.sender, "Must be owner of token.");
        _;
    }
    modifier ifNotDisabled() {
        require(!disabled, "Contract must not be disabled.");
        _;
    }
    function batchMint(string calldata _baseURI, uint256 _numberOfTokens)
        public
        onlyOwner
        ifNotDisabled
    {
        uint256 startTokenId = tokenIdCounter.current() + 1;
        uint256 endTokenId = startTokenId + _numberOfTokens - 1;
        tokenIdCounter = CountersUpgradeable.Counter(endTokenId);
        mintBatches.push(MintBatch(startTokenId, endTokenId, _baseURI));
        emit ConsecutiveTransfer(startTokenId, endTokenId, address(0), owner());
    }
    function addNewToken(string memory _uri) public onlyOwner ifNotDisabled {
        _createToken(
            _uri,
            msg.sender,
            msg.sender,
            defaultRoyaltyPercentage,
            msg.sender
        );
    }
    function mintTo(
        string calldata _uri,
        address _receiver,
        address _royaltyReceiver
    ) external onlyOwner ifNotDisabled {
        _createToken(
            _uri,
            msg.sender,
            _receiver,
            defaultRoyaltyPercentage,
            _royaltyReceiver
        );
    }
    function renounceOwnership() public view override onlyOwner {
        revert("unsupported");
    }
    function transferOwnership(address) public view override onlyOwner {
        revert("unsupported");
    }
    function deleteToken(uint256 _tokenId) public onlyTokenOwner(_tokenId) {
        burn(_tokenId);
    }
    function burn(uint256 _tokenId) public virtual override {
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        tokensBurned[_tokenId] = true;
        if (wasBatchMinted && !ERC721Upgradeable._exists(_tokenId)) {
            return;
        }
        ERC721BurnableUpgradeable.burn(_tokenId);
    }
    function tokenCreator(uint256)
        public
        view
        override
        returns (address payable)
    {
        return payable(owner());
    }
    function disableContract() public onlyOwner {
        disabled = true;
        emit ContractDisabled(msg.sender);
    }
    function setDefaultRoyaltyReceiver(address _receiver) external onlyOwner {
        _setDefaultRoyaltyReceiver(_receiver);
    }
    function setRoyaltyReceiverForToken(address _receiver, uint256 _tokenId)
        external
        onlyOwner
    {
        royaltyReceivers[_tokenId] = _receiver;
    }
    function _setTokenCreator(uint256 _tokenId, address _creator) internal {
        tokenCreators[_tokenId] = _creator;
    }
    function _createToken(
        string memory _uri,
        address _creator,
        address _to,
        uint256 _royaltyPercentage,
        address _royaltyReceiver
    ) internal returns (uint256) {
        tokenIdCounter.increment();
        uint256 tokenId = tokenIdCounter.current();
        _safeMint(_to, tokenId);
        _setTokenURI(tokenId, _uri);
        _setTokenCreator(tokenId, _creator);
        _setRoyaltyPercentage(tokenId, _royaltyPercentage);
        _setRoyaltyReceiver(tokenId, _royaltyReceiver);
        return tokenId;
    }
    ///////////////////////////////////////////////
    // Overriding Methods to support batch mints
    ///////////////////////////////////////////////
    function tokenURI(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (string memory)
    {
        (bool wasBatchMinted, , string memory baseTokenUri) = _batchMintInfo(
            _tokenId
        );
        if (!wasBatchMinted) {
            return super.tokenURI(_tokenId);
        } else {
            return
                string(
                    abi.encodePacked(
                        baseTokenUri,
                        "/",
                        _tokenId.toString(),
                        ".json"
                    )
                );
        }
    }
    function ownerOf(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (address)
    {
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        if (!wasBatchMinted) {
            return ERC721Upgradeable.ownerOf(_tokenId);
        } else if (tokensBurned[_tokenId]) {
            return ERC721Upgradeable.ownerOf(_tokenId);
        } else {
            if (!ERC721Upgradeable._exists(_tokenId)) {
                return owner();
            } else {
                return ERC721Upgradeable.ownerOf(_tokenId);
            }
        }
    }
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = 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);
    }
    function _isApprovedOrOwner(address _spender, uint256 _tokenId)
        internal
        view
        virtual
        override
        returns (bool)
    {
        address owner = ownerOf(_tokenId);
        return (_spender == owner ||
            getApproved(_tokenId) == _spender ||
            isApprovedForAll(owner, _spender));
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal override {
        _tokenApprovals[tokenId] = to;
        emit Approval(ownerOf(tokenId), to, tokenId); // internal owner
    }
    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (address)
    {
        address receiver = royaltyReceivers[_tokenId];
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        bool exists = (wasBatchMinted || receiver != address(0)) &&
            !tokensBurned[_tokenId];
        require(exists, "ERC721: approved query for nonexistent token");
        return _tokenApprovals[_tokenId];
    }
    function _transfer(
        address _from,
        address _to,
        uint256 _tokenId
    ) internal virtual override {
        require(_tokenId != 0);
        (bool wasBatchMinted, , ) = _batchMintInfo(_tokenId);
        if (
            wasBatchMinted &&
            !ERC721Upgradeable._exists(_tokenId) &&
            !tokensBurned[_tokenId]
        ) {
            _mint(_from, _tokenId);
        }
        ERC721Upgradeable._transfer(_from, _to, _tokenId);
    }
    function totalSupply() public view virtual override returns (uint256) {
        return tokenIdCounter.current();
    }
    function _batchMintInfo(uint256 _tokenId)
        internal
        view
        returns (
            bool _wasBatchMinted,
            uint256 _batchIndex,
            string memory _baseTokenUri
        )
    {
        for (uint256 i = 0; i < mintBatches.length; i++) {
            if (
                _tokenId >= mintBatches[i].startTokenId &&
                _tokenId <= mintBatches[i].endTokenId
            ) {
                return (true, i, mintBatches[i].baseURI);
            }
        }
        return (false, 0, "");
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../utils/ContextUpgradeable.sol";
import "./IERC721Upgradeable.sol";
import "./IERC721MetadataUpgradeable.sol";
import "./IERC721EnumerableUpgradeable.sol";
import "./IERC721ReceiverUpgradeable.sol";
import "../../introspection/ERC165Upgradeable.sol";
import "../../math/SafeMathUpgradeable.sol";
import "../../utils/AddressUpgradeable.sol";
import "../../utils/EnumerableSetUpgradeable.sol";
import "../../utils/EnumerableMapUpgradeable.sol";
import "../../utils/StringsUpgradeable.sol";
import "../../proxy/Initializable.sol";
/**
 * @title ERC721 Non-Fungible Token Standard basic implementation
 * @dev see https://eips.ethereum.org/EIPS/eip-721
 */
contract ERC721Upgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721Upgradeable, IERC721MetadataUpgradeable, IERC721EnumerableUpgradeable {
    using SafeMathUpgradeable for uint256;
    using AddressUpgradeable for address;
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.UintSet;
    using EnumerableMapUpgradeable for EnumerableMapUpgradeable.UintToAddressMap;
    using StringsUpgradeable for uint256;
    // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
    // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
    // Mapping from holder address to their (enumerable) set of owned tokens
    mapping (address => EnumerableSetUpgradeable.UintSet) private _holderTokens;
    // Enumerable mapping from token ids to their owners
    EnumerableMapUpgradeable.UintToAddressMap private _tokenOwners;
    // 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;
    // Token name
    string private _name;
    // Token symbol
    string private _symbol;
    // Optional mapping for token URIs
    mapping (uint256 => string) private _tokenURIs;
    // Base URI
    string private _baseURI;
    /*
     *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231
     *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
     *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
     *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
     *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
     *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
     *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
     *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
     *
     *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
     *        0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
     */
    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
    /*
     *     bytes4(keccak256('name()')) == 0x06fdde03
     *     bytes4(keccak256('symbol()')) == 0x95d89b41
     *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
     *
     *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
     */
    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
    /*
     *     bytes4(keccak256('totalSupply()')) == 0x18160ddd
     *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
     *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
     *
     *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
     */
    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    function __ERC721_init(string memory name_, string memory symbol_) internal initializer {
        __Context_init_unchained();
        __ERC165_init_unchained();
        __ERC721_init_unchained(name_, symbol_);
    }
    function __ERC721_init_unchained(string memory name_, string memory symbol_) internal initializer {
        _name = name_;
        _symbol = symbol_;
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(_INTERFACE_ID_ERC721);
        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
    }
    /**
     * @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 _holderTokens[owner].length();
    }
    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
    }
    /**
     * @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 _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));
        }
        // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
        return string(abi.encodePacked(base, tokenId.toString()));
    }
    /**
    * @dev Returns the base URI set via {_setBaseURI}. This will be
    * automatically added as a prefix in {tokenURI} to each token's URI, or
    * to the token ID if no specific URI is set for that token ID.
    */
    function baseURI() public view virtual returns (string memory) {
        return _baseURI;
    }
    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
        return _holderTokens[owner].at(index);
    }
    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
        return _tokenOwners.length();
    }
    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        (uint256 tokenId, ) = _tokenOwners.at(index);
        return tokenId;
    }
    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721Upgradeable.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");
        require(_msgSender() == owner || ERC721Upgradeable.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 {
        require(operator != _msgSender(), "ERC721: approve to caller");
        _operatorApprovals[_msgSender()][operator] = approved;
        emit ApprovalForAll(_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 _tokenOwners.contains(tokenId);
    }
    /**
     * @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 = ERC721Upgradeable.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || ERC721Upgradeable.isApprovedForAll(owner, spender));
    }
    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     d*
     * - `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);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(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 = ERC721Upgradeable.ownerOf(tokenId); // internal owner
        _beforeTokenTransfer(owner, address(0), tokenId);
        // Clear approvals
        _approve(address(0), tokenId);
        // Clear metadata (if any)
        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
        _holderTokens[owner].remove(tokenId);
        _tokenOwners.remove(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(ERC721Upgradeable.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own"); // internal 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);
        _holderTokens[from].remove(tokenId);
        _holderTokens[to].add(tokenId);
        _tokenOwners.set(tokenId, to);
        emit Transfer(from, to, 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), "ERC721Metadata: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }
    /**
     * @dev Internal function to set the base URI for all token IDs. It is
     * automatically added as a prefix to the value returned in {tokenURI},
     * or to the token ID if {tokenURI} is empty.
     */
    function _setBaseURI(string memory baseURI_) internal virtual {
        _baseURI = baseURI_;
    }
    /**
     * @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()) {
            return true;
        }
        bytes memory returndata = to.functionCall(abi.encodeWithSelector(
            IERC721ReceiverUpgradeable(to).onERC721Received.selector,
            _msgSender(),
            from,
            tokenId,
            _data
        ), "ERC721: transfer to non ERC721Receiver implementer");
        bytes4 retval = abi.decode(returndata, (bytes4));
        return (retval == _ERC721_RECEIVED);
    }
    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits an {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721Upgradeable.ownerOf(tokenId), to, tokenId); // internal owner
    }
    /**
     * @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 { }
    uint256[41] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../utils/ContextUpgradeable.sol";
import "./ERC721Upgradeable.sol";
import "../../proxy/Initializable.sol";
/**
 * @title ERC721 Burnable Token
 * @dev ERC721 Token that can be irreversibly burned (destroyed).
 */
abstract contract ERC721BurnableUpgradeable is Initializable, ContextUpgradeable, ERC721Upgradeable {
    function __ERC721Burnable_init() internal initializer {
        __Context_init_unchained();
        __ERC165_init_unchained();
        __ERC721Burnable_init_unchained();
    }
    function __ERC721Burnable_init_unchained() internal initializer {
    }
    /**
     * @dev Burns `tokenId`. See {ERC721-_burn}.
     *
     * Requirements:
     *
     * - The caller must own `tokenId` or be an approved operator.
     */
    function burn(uint256 tokenId) public virtual {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
        _burn(tokenId);
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC165Upgradeable.sol";
import "../proxy/Initializable.sol";
/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts may inherit from this and call {_registerInterface} to declare
 * their support of an interface.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    /*
     * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
     */
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
    /**
     * @dev Mapping of interface ids to whether or not it's supported.
     */
    mapping(bytes4 => bool) private _supportedInterfaces;
    function __ERC165_init() internal initializer {
        __ERC165_init_unchained();
    }
    function __ERC165_init_unchained() internal initializer {
        // Derived contracts need only register support for their own interfaces,
        // we register support for ERC165 itself here
        _registerInterface(_INTERFACE_ID_ERC165);
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     *
     * Time complexity O(1), guaranteed to always use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return _supportedInterfaces[interfaceId];
    }
    /**
     * @dev Registers the contract as an implementer of the interface defined by
     * `interfaceId`. Support of the actual ERC165 interface is automatic and
     * registering its interface id is not required.
     *
     * See {IERC165-supportsInterface}.
     *
     * Requirements:
     *
     * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
     */
    function _registerInterface(bytes4 interfaceId) internal virtual {
        require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
        _supportedInterfaces[interfaceId] = true;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../utils/ContextUpgradeable.sol";
import "../proxy/Initializable.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 OwnableUpgradeable is Initializable, ContextUpgradeable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    function __Ownable_init() internal initializer {
        __Context_init_unchained();
        __Ownable_init_unchained();
    }
    function __Ownable_init_unchained() internal initializer {
        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;
    }
    uint256[49] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../math/SafeMathUpgradeable.sol";
/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath}
 * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
 * directly accessed.
 */
library CountersUpgradeable {
    using SafeMathUpgradeable for uint256;
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }
    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }
    function increment(Counter storage counter) internal {
        // The {SafeMath} overflow check can be skipped here, see the comment at the top
        counter._value += 1;
    }
    function decrement(Counter storage counter) internal {
        counter._value = counter._value.sub(1);
    }
}
// contracts/token/ERC721/IERC721Creator.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/**
 * @title IERC721 Non-Fungible Token Creator basic interface
 */
abstract contract IERC721Creator {
    /**
     * @dev Gets the creator of the token
     * @param _tokenId uint256 ID of the token
     * @return address of the creator
     */
    function tokenCreator(uint256 _tokenId)
        public
        view
        virtual
        returns (address payable);
    function calcIERC721CreatorInterfaceId() public pure returns (bytes4) {
        return this.tokenCreator.selector;
    }
}
// contracts/royalty/ERC2981.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-upgradeable-0.7.2/introspection/ERC165Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable-0.7.2/math/SafeMathUpgradeable.sol";
import "./IERC2981.sol";
abstract contract ERC2981Upgradeable is IERC2981, ERC165Upgradeable {
    using SafeMathUpgradeable for uint256;
    // bytes4(keccak256("royaltyInfo(uint256,uint256)")) == 0x2a55205a
    bytes4 private constant _INTERFACE_ID_ERC2981 = 0x2a55205a;
    address public defaultRoyaltyReceiver;
    mapping(uint256 => address) royaltyReceivers;
    mapping(uint256 => uint256) royaltyPercentages;
    constructor() {}
    function __ERC2981__init() internal initializer {
        __ERC165_init();
        _registerInterface(_INTERFACE_ID_ERC2981);
    }
    function royaltyInfo(uint256 _tokenId, uint256 _salePrice)
        public
        view
        virtual
        override
        returns (address receiver, uint256 royaltyAmount)
    {
        receiver = royaltyReceivers[_tokenId] != address(0)
            ? royaltyReceivers[_tokenId]
            : defaultRoyaltyReceiver;
        royaltyAmount = _salePrice.mul(royaltyPercentages[_tokenId]).div(100);
    }
    function _setDefaultRoyaltyReceiver(address _receiver) internal {
        defaultRoyaltyReceiver = _receiver;
    }
    function _setRoyaltyReceiver(uint256 _tokenId, address _newReceiver)
        internal
    {
        royaltyReceivers[_tokenId] = _newReceiver;
    }
    function _setRoyaltyPercentage(uint256 _tokenId, uint256 _percentage)
        internal
    {
        royaltyPercentages[_tokenId] = _percentage;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../proxy/Initializable.sol";
/*
 * @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 GSN 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 ContextUpgradeable is Initializable {
    function __Context_init() internal initializer {
        __Context_init_unchained();
    }
    function __Context_init_unchained() internal initializer {
    }
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
    uint256[50] private __gap;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "../../introspection/IERC165Upgradeable.sol";
/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721Upgradeable is IERC165Upgradeable {
    /**
     * @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;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721Upgradeable.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721MetadataUpgradeable is IERC721Upgradeable {
    /**
     * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
import "./IERC721Upgradeable.sol";
/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721EnumerableUpgradeable is IERC721Upgradeable {
    /**
     * @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);
    /**
     * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
     * Use along with {totalSupply} to enumerate all tokens.
     */
    function tokenByIndex(uint256 index) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721ReceiverUpgradeable {
    /**
     * @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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMathUpgradeable {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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);
    }
    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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.
    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];
        if (valueIndex != 0) { // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;
            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            bytes32 lastvalue = set._values[lastIndex];
            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved value was stored
            set._values.pop();
            // Delete the index for the deleted slot
            delete set._indexes[value];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        require(set._values.length > index, "EnumerableSet: index out of bounds");
        return set._values[index];
    }
    // Bytes32Set
    struct Bytes32Set {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }
    // AddressSet
    struct AddressSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }
    // UintSet
    struct UintSet {
        Set _inner;
    }
    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }
    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }
    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }
   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev Library for managing an enumerable variant of Solidity's
 * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
 * type.
 *
 * Maps have the following properties:
 *
 * - Entries are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Entries are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableMap for EnumerableMap.UintToAddressMap;
 *
 *     // Declare a set state variable
 *     EnumerableMap.UintToAddressMap private myMap;
 * }
 * ```
 *
 * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
 * supported.
 */
library EnumerableMapUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Map type with
    // bytes32 keys and values.
    // The Map implementation uses private functions, and user-facing
    // implementations (such as Uint256ToAddressMap) are just wrappers around
    // the underlying Map.
    // This means that we can only create new EnumerableMaps for types that fit
    // in bytes32.
    struct MapEntry {
        bytes32 _key;
        bytes32 _value;
    }
    struct Map {
        // Storage of map keys and values
        MapEntry[] _entries;
        // Position of the entry defined by a key in the `entries` array, plus 1
        // because index 0 means a key is not in the map.
        mapping (bytes32 => uint256) _indexes;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) { // Equivalent to !contains(map, key)
            map._entries.push(MapEntry({ _key: key, _value: value }));
            // The entry is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            map._indexes[key] = map._entries.length;
            return true;
        } else {
            map._entries[keyIndex - 1]._value = value;
            return false;
        }
    }
    /**
     * @dev Removes a key-value pair from a map. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function _remove(Map storage map, bytes32 key) private returns (bool) {
        // We read and store the key's index to prevent multiple reads from the same storage slot
        uint256 keyIndex = map._indexes[key];
        if (keyIndex != 0) { // Equivalent to contains(map, key)
            // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one
            // in the array, and then remove the last entry (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.
            uint256 toDeleteIndex = keyIndex - 1;
            uint256 lastIndex = map._entries.length - 1;
            // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
            MapEntry storage lastEntry = map._entries[lastIndex];
            // Move the last entry to the index where the entry to delete is
            map._entries[toDeleteIndex] = lastEntry;
            // Update the index for the moved entry
            map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based
            // Delete the slot where the moved entry was stored
            map._entries.pop();
            // Delete the index for the deleted slot
            delete map._indexes[key];
            return true;
        } else {
            return false;
        }
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function _contains(Map storage map, bytes32 key) private view returns (bool) {
        return map._indexes[key] != 0;
    }
    /**
     * @dev Returns the number of key-value pairs in the map. O(1).
     */
    function _length(Map storage map) private view returns (uint256) {
        return map._entries.length;
    }
   /**
    * @dev Returns the key-value pair stored at position `index` in the map. O(1).
    *
    * Note that there are no guarantees on the ordering of entries inside the
    * array, and it may change when more entries are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {
        require(map._entries.length > index, "EnumerableMap: index out of bounds");
        MapEntry storage entry = map._entries[index];
        return (entry._key, entry._value);
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     */
    function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {
        uint256 keyIndex = map._indexes[key];
        if (keyIndex == 0) return (false, 0); // Equivalent to contains(map, key)
        return (true, map._entries[keyIndex - 1]._value); // All indexes are 1-based
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function _get(Map storage map, bytes32 key) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, "EnumerableMap: nonexistent key"); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    /**
     * @dev Same as {_get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {_tryGet}.
     */
    function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {
        uint256 keyIndex = map._indexes[key];
        require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)
        return map._entries[keyIndex - 1]._value; // All indexes are 1-based
    }
    // UintToAddressMap
    struct UintToAddressMap {
        Map _inner;
    }
    /**
     * @dev Adds a key-value pair to a map, or updates the value for an existing
     * key. O(1).
     *
     * Returns true if the key was added to the map, that is if it was not
     * already present.
     */
    function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {
        return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
    }
    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the key was removed from the map, that is if it was present.
     */
    function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
        return _remove(map._inner, bytes32(key));
    }
    /**
     * @dev Returns true if the key is in the map. O(1).
     */
    function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
        return _contains(map._inner, bytes32(key));
    }
    /**
     * @dev Returns the number of elements in the map. O(1).
     */
    function length(UintToAddressMap storage map) internal view returns (uint256) {
        return _length(map._inner);
    }
   /**
    * @dev Returns the element stored at position `index` in the set. O(1).
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
        (bytes32 key, bytes32 value) = _at(map._inner, index);
        return (uint256(key), address(uint160(uint256(value))));
    }
    /**
     * @dev Tries to returns the value associated with `key`.  O(1).
     * Does not revert if `key` is not in the map.
     *
     * _Available since v3.4._
     */
    function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));
        return (success, address(uint160(uint256(value))));
    }
    /**
     * @dev Returns the value associated with `key`.  O(1).
     *
     * Requirements:
     *
     * - `key` must be in the map.
     */
    function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key)))));
    }
    /**
     * @dev Same as {get}, with a custom error message when `key` is not in the map.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryGet}.
     */
    function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {
        return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @dev String operations.
 */
library StringsUpgradeable {
    /**
     * @dev Converts a `uint256` to its ASCII `string` 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);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = bytes1(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }
}
// SPDX-License-Identifier: MIT
// solhint-disable-next-line compiler-version
pragma solidity >=0.4.24 <0.8.0;
import "../utils/AddressUpgradeable.sol";
/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;
    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;
    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier initializer() {
        require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
        }
    }
    /// @dev Returns true if and only if the function is running in the constructor
    function _isConstructor() private view returns (bool) {
        return !AddressUpgradeable.isContract(address(this));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
 * @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 IERC165Upgradeable {
    /**
     * @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);
}
// contracts/royalty/IERC2981.sol
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @dev Interface for the NFT Royalty Standard
interface IERC2981 {
    /// 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);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
import "@openzeppelin/contracts-0.7.2/payment/PullPayment.sol";
import "@openzeppelin/contracts-0.7.2/math/SafeMath.sol";
import "./IPayments.sol";
/**
 * @title Payments contract for SuperRare Marketplaces.
 */
contract Payments is IPayments, PullPayment {
    using SafeMath for uint256;
    /////////////////////////////////////////////////////////////////////////
    // refund
    /////////////////////////////////////////////////////////////////////////
    /**
     * @dev Internal function to refund an address. Typically for canceled bids or offers.
     * Requirements:
     *
     *  - _payee cannot be the zero address
     *
     * @param _amount uint256 value to be split.
     * @param _payee address seller of the token.
     */
    function refund(address _payee, uint256 _amount) external payable override {
        require(
            _payee != address(0),
            "refund::no payees can be the zero address"
        );
        require(msg.value == _amount);
        if (_amount > 0) {
            (bool success, ) = address(_payee).call{value: _amount}("");
            if (!success) {
                _asyncTransfer(_payee, _amount);
            }
        }
    }
    /////////////////////////////////////////////////////////////////////////
    // payout
    /////////////////////////////////////////////////////////////////////////
    function payout(address[] calldata _splits, uint256[] calldata _amounts)
        external
        payable
        override
    {
        uint256 totalAmount = 0;
        for (uint256 i = 0; i < _splits.length; i++) {
            totalAmount = totalAmount.add(_amounts[i]);
            if (_splits[i] != address(0)) {
                (bool success, ) = address(_splits[i]).call{value: _amounts[i]}(
                    ""
                );
                if (!success) {
                    _asyncTransfer(_splits[i], _amounts[i]);
                }
            }
        }
        require(msg.value == totalAmount, "payout::not enough sent");
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <0.8.0;
import "./escrow/Escrow.sol";
/**
 * @dev Simple implementation of a
 * https://consensys.github.io/smart-contract-best-practices/recommendations/#favor-pull-over-push-for-external-calls[pull-payment]
 * strategy, where the paying contract doesn't interact directly with the
 * receiver account, which must withdraw its payments itself.
 *
 * Pull-payments are often considered the best practice when it comes to sending
 * Ether, security-wise. It prevents recipients from blocking execution, and
 * eliminates reentrancy concerns.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 *
 * To use, derive from the `PullPayment` contract, and use {_asyncTransfer}
 * instead of Solidity's `transfer` function. Payees can query their due
 * payments with {payments}, and retrieve them with {withdrawPayments}.
 */
abstract contract PullPayment {
    Escrow private _escrow;
    constructor () internal {
        _escrow = new Escrow();
    }
    /**
     * @dev Withdraw accumulated payments, forwarding all gas to the recipient.
     *
     * Note that _any_ account can call this function, not just the `payee`.
     * This means that contracts unaware of the `PullPayment` protocol can still
     * receive funds this way, by having a separate account call
     * {withdrawPayments}.
     *
     * WARNING: Forwarding all gas opens the door to reentrancy vulnerabilities.
     * Make sure you trust the recipient, or are either following the
     * checks-effects-interactions pattern or using {ReentrancyGuard}.
     *
     * @param payee Whose payments will be withdrawn.
     */
    function withdrawPayments(address payable payee) public virtual {
        _escrow.withdraw(payee);
    }
    /**
     * @dev Returns the payments owed to an address.
     * @param dest The creditor's address.
     */
    function payments(address dest) public view returns (uint256) {
        return _escrow.depositsOf(dest);
    }
    /**
     * @dev Called by the payer to store the sent amount as credit to be pulled.
     * Funds sent in this way are stored in an intermediate {Escrow} contract, so
     * there is no danger of them being spent before withdrawal.
     *
     * @param dest The destination address of the funds.
     * @param amount The amount to transfer.
     */
    function _asyncTransfer(address dest, uint256 amount) internal virtual {
        _escrow.deposit{ value: amount }(dest);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }
    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) return 0;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }
    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.3;
/// @author koloz
/// @title IPayments
/// @notice Interface for the Payments contract used.
interface IPayments {
    function refund(address _payee, uint256 _amount) external payable;
    function payout(address[] calldata _splits, uint256[] calldata _amounts)
        external
        payable;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../../math/SafeMath.sol";
import "../../access/Ownable.sol";
import "../../utils/Address.sol";
 /**
  * @title Escrow
  * @dev Base escrow contract, holds funds designated for a payee until they
  * withdraw them.
  *
  * Intended usage: This contract (and derived escrow contracts) should be a
  * standalone contract, that only interacts with the contract that instantiated
  * it. That way, it is guaranteed that all Ether will be handled according to
  * the `Escrow` rules, and there is no need to check for payable functions or
  * transfers in the inheritance tree. The contract that uses the escrow as its
  * payment method should be its owner, and provide public methods redirecting
  * to the escrow's deposit and withdraw.
  */
contract Escrow is Ownable {
    using SafeMath for uint256;
    using Address for address payable;
    event Deposited(address indexed payee, uint256 weiAmount);
    event Withdrawn(address indexed payee, uint256 weiAmount);
    mapping(address => uint256) private _deposits;
    function depositsOf(address payee) public view returns (uint256) {
        return _deposits[payee];
    }
    /**
     * @dev Stores the sent amount as credit to be withdrawn.
     * @param payee The destination address of the funds.
     */
    function deposit(address payee) public payable virtual onlyOwner {
        uint256 amount = msg.value;
        _deposits[payee] = _deposits[payee].add(amount);
        emit Deposited(payee, amount);
    }
    /**
     * @dev Withdraw accumulated balance for a payee, forwarding all gas to the
     * recipient.
     *
     * WARNING: Forwarding all gas opens the door to reentrancy vulnerabilities.
     * Make sure you trust the recipient, or are either following the
     * checks-effects-interactions pattern or using {ReentrancyGuard}.
     *
     * @param payee The address whose funds will be withdrawn and transferred to.
     */
    function withdraw(address payable payee) public virtual onlyOwner {
        uint256 payment = _deposits[payee];
        _deposits[payee] = 0;
        payee.sendValue(payment);
        emit Withdrawn(payee, payment);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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 () internal {
        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;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2 <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);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <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 GSN 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 payable) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}