// File: contracts/WITHS.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.15;

import {ERC721Psi} from './ERC721Psi.sol';
import {ERC2981Base, ERC2981ContractWideRoyalties} from './ERC2981ContractWideRoyalties.sol';
import {Ownable} from '@openzeppelin/contracts/access/Ownable.sol';
import {Strings} from '@openzeppelin/contracts/utils/Strings.sol';

/**
 * @author Contract written by Duffles (https://github.com/DefiMatt) for
 * project 'Wish I Had The Same'.
 */
contract WIHTS is ERC721Psi, ERC2981ContractWideRoyalties, Ownable {
  using Strings for uint256;

  /*//////////////////////////////////////////////////////////////
    Public state.
  //////////////////////////////////////////////////////////////*/

  /// @notice Base URI for computing {tokenURI}.
  string public baseURI;
  /// @notice The number of NFTs claimed per address.
  mapping(address => uint256) public claimed;
  /// @notice The number of NFTs minted for free.
  uint256 public freeMints;
  /// @notice Whether the mint has been closed.
  bool public mintClosed;
  /// @notice The price in wei per NFT.
  uint256 public price = 0.0079 ether;
  /// @notice URI for {tokenURI} before the reveal.
  string public unrevealedURI = 'https://arweave.net/TdxegBMOs1GtUdFHoN2sMC5L9dH5mx_A6SfI5SfyvY0';

  /*//////////////////////////////////////////////////////////////
    Errors.
  //////////////////////////////////////////////////////////////*/

  /**
   * @notice The attempt to mint the requested amount of NFTs would exceed the
   * maximum number of NFTs allowed per wallet.
   *
   * @param counterfactualNumberInWallet What the number of NFTs minted by the
   * recipient wallet would have been if the requested amount of NFTs were
   * minted.
   */
  error MaximumPerWalletExceeded(uint256 counterfactualNumberInWallet);
  /**
   * @notice The attempt to mint the requested amount of NFTs would exceed the
   * maximum supply allowed.
   *
   * @param counterfactualNewSupply What the total supply would have been if the
   * requested amount of NFTs were minted.
   */
  error MaximumSupplyExceeded(uint256 counterfactualNewSupply);
  /// @notice Attempted to mint after minting was closed.
  error MintClosed();
  /// @notice Attempted to set royalties beyond the permitted maximum.
  error RoyaltiesTooHigh();
  /// @notice Attempted to query for a non-existent token.
  error TokenNonexistent();
  /**
   * @notice The wrong fee was supplied with the attempt to mint the requested
   * amount of NFTs.
   *
   * @param expectedFee The fee required to mint the amount of NFTs requested.
   * @param receivedFee The incorrect fee received.
   */
  error WrongFee(uint256 expectedFee, uint256 receivedFee);
  /// @notice Attempted to mint zero NFTs.
  error ZeroMintsRequested();

  /*//////////////////////////////////////////////////////////////
    Public functions.
  //////////////////////////////////////////////////////////////*/

  /**
   * @notice Mint one or more NFTs to the sender. If there are free mints
   * remaining and the sender hasn't minted yet, they get the first one free.
   *
   * @param amount How many to mint.
   */
  function mint(uint256 amount) external payable {
    if (mintClosed) revert MintClosed();
    if (0 == amount) revert ZeroMintsRequested();

    uint256 newSupply = totalSupply() + amount;
    if (newSupply > 5_000) revert MaximumSupplyExceeded(newSupply);

    uint256 _claimed = claimed[msg.sender];
    uint256 newClaimed = _claimed + amount;

    if (newClaimed > 10) revert MaximumPerWalletExceeded(newClaimed);

    uint256 expectedFee;

    if (0 == _claimed && freeMints < 2_000) {
      expectedFee = price * (amount - 1);
      ++freeMints;
    } else {
      expectedFee = price * amount;
    }

    if (msg.value != expectedFee) revert WrongFee(expectedFee, msg.value);

    claimed[msg.sender] = newClaimed;
    _mint(msg.sender, amount);
  }

  /*//////////////////////////////////////////////////////////////
    Constructor.
  //////////////////////////////////////////////////////////////*/

  constructor() ERC721Psi('Wish I Had The Same', 'WIHTS') {
    // Initial royalties of 2.5%.
    _setRoyalties(address(0xb291b5b2C35CD515CCb333b1Ebd688942ed1966c), 250);
    _transferOwnership(address(0xb291b5b2C35CD515CCb333b1Ebd688942ed1966c));
  }

  /*//////////////////////////////////////////////////////////////
    Privileged functions.
  //////////////////////////////////////////////////////////////*/

  /**
   * @notice Close minting.
   *
   * @dev Can only be used by the owner.
   */
  function closeMint() external onlyOwner {
    mintClosed = true;
  }

  /**
   * @notice Change {baseURI}.
   *
   * @dev Can only be used by the owner.
   *
   * @param newBaseURI The new {baseURI}.
   */
  function setBaseURI(string calldata newBaseURI) external onlyOwner {
    baseURI = newBaseURI;
  }

  /**
   * @notice Change {price} per NFT.
   *
   * @dev Can only be used by the owner.
   *
   * @param newPrice The new {price} in wei per NFT.
   */
  function setPrice(uint256 newPrice) external onlyOwner {
    price = newPrice;
  }

  /**
   * @notice Change royalties (see {ERC2981ContractWideRoyalties-royaltyInfo}).
   *
   * @dev Can only be used by the owner.
   *
   * @param royaltyReceiver Address to receive royalty payments.
   * @param royaltyAmount Permyriadage / basis points (‱) of sale amounts to be
   * paid as royalties.
   */
  function setRoyalties(address royaltyReceiver, uint256 royaltyAmount)
    external
    onlyOwner
  {
    // Maximum royalties of 7.5%.
    if (royaltyAmount > 750) revert RoyaltiesTooHigh();

    _setRoyalties(royaltyReceiver, royaltyAmount);
  }

  /**
   * @notice Change {unrevealedURI}.
   *
   * @dev Can only be used by the owner.
   *
   * @param _unrevealedURI URI for {tokenURI} before the reveal.
   */
  function setUnrevealedURI(string memory _unrevealedURI) external onlyOwner {
    unrevealedURI = _unrevealedURI;
  }

  /**
   * @notice Withdraw accumulated Ether.
   */
  function withdraw() external onlyOwner {
    payable(address(0x354Fccdaa678cdebc25CDf297930e32F86EC6E18)).transfer(
      address(this).balance / 10
    );
    payable(owner()).transfer(address(this).balance);
  }

  /*//////////////////////////////////////////////////////////////
    View functions.
  //////////////////////////////////////////////////////////////*/

  /**
   * @notice Returns the URI for the token with id `tokenId`.
   *
   * @dev Returns {unrevealedURI} pre-reveal, and the concatenation of
   * {baseURI}, `tokenId` and '.json' post-reveal (see {baseURI} for more
   * details).
   *
   * @param tokenId The token id to get the URI for.
   * @return The URI for the token.
   */
  function tokenURI(uint256 tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    if (!_exists(tokenId)) revert TokenNonexistent();

    return
      0 == bytes(baseURI).length
        ? unrevealedURI
        : string(abi.encodePacked(baseURI, (tokenId + 1).toString(), '.json'));
  }

  /**
   * @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)
    public
    view
    virtual
    override(ERC721Psi, ERC2981Base)
    returns (bool)
  {
    return super.supportsInterface(interfaceId);
  }
}

// File: contracts/ERC721Psi.sol



// SPDX-License-Identifier: MIT
/**
  ______ _____   _____ ______ ___  __ _  _  _ 
 |  ____|  __ \ / ____|____  |__ \/_ | || || |
 | |__  | |__) | |        / /   ) || | \| |/ |
 |  __| |  _  /| |       / /   / / | |\_   _/ 
 | |____| | \ \| |____  / /   / /_ | |  | |   
 |______|_|  \_\\_____|/_/   |____||_|  |_|   
                                              
                                            
 */

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/StorageSlot.sol";
import "./BitMaps.sol";


contract ERC721Psi is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable {
    using Address for address;
    using Strings for uint256;
    using BitMaps for BitMaps.BitMap;

    BitMaps.BitMap private _batchHead;

    string private _name;
    string private _symbol;

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

    mapping(uint256 => address) private _tokenApprovals;
    mapping(address => mapping(address => bool)) private _operatorApprovals;

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

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override(ERC165, IERC165)
        returns (bool)
    {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            interfaceId == type(IERC721Enumerable).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) 
        public 
        view 
        virtual 
        override 
        returns (uint) 
    {
        require(owner != address(0), "ERC721Psi: balance query for the zero address");

        uint count;
        for( uint i; i < _minted; ++i ){
            if(_exists(i)){
                if( owner == ownerOf(i)){
                    ++count;
                }
            }
        }
        return count;
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId)
        public
        view
        virtual
        override
        returns (address)
    {
        (address owner, uint256 tokenIdBatchHead) = _ownerAndBatchHeadOf(tokenId);
        return owner;
    }

    function _ownerAndBatchHeadOf(uint256 tokenId) internal view returns (address owner, uint256 tokenIdBatchHead){
        require(_exists(tokenId), "ERC721Psi: owner query for nonexistent token");
        tokenIdBatchHead = _getBatchHead(tokenId);
        owner = _owners[tokenIdBatchHead];
    }

    /**
     * @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), "ERC721Psi: URI query for nonexistent token");

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

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


    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ownerOf(tokenId);
        require(to != owner, "ERC721Psi: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721Psi: 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),
            "ERC721Psi: approved query for nonexistent token"
        );

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved)
        public
        virtual
        override
    {
        require(operator != _msgSender(), "ERC721Psi: 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),
            "ERC721Psi: 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),
            "ERC721Psi: 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, 1,_data),
            "ERC721Psi: 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`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return tokenId < _minted;
    }

    /**
     * @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),
            "ERC721Psi: operator query for nonexistent token"
        );
        address owner = ownerOf(tokenId);
        return (spender == owner ||
            getApproved(tokenId) == spender ||
            isApprovedForAll(owner, spender));
    }

    /**
     * @dev Safely mints `quantity` tokens and transfers them to `to`.
     *
     * Requirements:
     *
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called for each safe transfer.
     * - `quantity` must be greater than 0.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 quantity) internal virtual {
        _safeMint(to, quantity, "");
    }

    
    function _safeMint(
        address to,
        uint256 quantity,
        bytes memory _data
    ) internal virtual {
        uint256 startTokenId = _minted;
        _mint(to, quantity);
        require(
            _checkOnERC721Received(address(0), to, startTokenId, quantity, _data),
            "ERC721Psi: transfer to non ERC721Receiver implementer"
        );
    }


    function _mint(
        address to,
        uint256 quantity
    ) internal virtual {
        uint256 tokenIdBatchHead = _minted;
        
        require(quantity > 0, "ERC721Psi: quantity must be greater 0");
        require(to != address(0), "ERC721Psi: mint to the zero address");
        
        _beforeTokenTransfers(address(0), to, tokenIdBatchHead, quantity);
        _minted += quantity;
        _owners[tokenIdBatchHead] = to;
        _batchHead.set(tokenIdBatchHead);
        _afterTokenTransfers(address(0), to, tokenIdBatchHead, quantity);
        
        // Emit events
        for(uint256 tokenId=tokenIdBatchHead;tokenId < tokenIdBatchHead + quantity; tokenId++){
            emit Transfer(address(0), to, 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 {
        (address owner, uint256 tokenIdBatchHead) = _ownerAndBatchHeadOf(tokenId);

        require(
            owner == from,
            "ERC721Psi: transfer of token that is not own"
        );
        require(to != address(0), "ERC721Psi: transfer to the zero address");

        _beforeTokenTransfers(from, to, tokenId, 1);

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

        uint256 nextTokenId = tokenId + 1;

        if(!_batchHead.get(nextTokenId) &&  
            nextTokenId < _minted
        ) {
            _owners[nextTokenId] = from;
            _batchHead.set(nextTokenId);
        }

        _owners[tokenId] = to;
        if(tokenId != tokenIdBatchHead) {
            _batchHead.set(tokenId);
        }

        emit Transfer(from, to, tokenId);

        _afterTokenTransfers(from, to, tokenId, 1);
    }

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

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param startTokenId uint256 the first ID of the tokens to be transferred
     * @param quantity uint256 amount of the tokens to be transfered.
     * @param _data bytes optional data to send along with the call
     * @return r bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity,
        bytes memory _data
    ) private returns (bool r) {
        if (to.isContract()) {
            r = true;
            for(uint256 tokenId = startTokenId; tokenId < startTokenId + quantity; tokenId++){
                try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                    r = r && retval == IERC721Receiver.onERC721Received.selector;
                } catch (bytes memory reason) {
                    if (reason.length == 0) {
                        revert("ERC721Psi: transfer to non ERC721Receiver implementer");
                    } else {
                        assembly {
                            revert(add(32, reason), mload(reason))
                        }
                    }
                }
            }
            return r;
        } else {
            return true;
        }
    }

    function _getBatchHead(uint256 tokenId) internal view returns (uint256 tokenIdBatchHead) {
        tokenIdBatchHead = _batchHead.scanForward(tokenId); 
    }

    /**
     * @dev See {IERC721Enumerable-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _minted;
    }

    /**
     * @dev See {IERC721Enumerable-tokenByIndex}.
     */
    function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
        require(index < totalSupply(), "ERC721Psi: global index out of bounds");
        
        uint count;
        for(uint i; i < _minted; i++){
            if(_exists(i)){
                if(count == index) return i;
                else count++;
            }
        }
    }

    /**
     * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256 tokenId) {
        uint count;
        for(uint i; i < _minted; i++){
            if(_exists(i) && owner == ownerOf(i)){
                if(count == index) return i;
                else count++;
            }
        }

        revert("ERC721Psi: owner index out of bounds");
    }


    /**
     * @dev Hook that is called before a set of serially-ordered token ids are about to be transferred. This includes minting.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * 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`.
     */
    function _beforeTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}

    /**
     * @dev Hook that is called after a set of serially-ordered token ids have been transferred. This includes
     * minting.
     *
     * startTokenId - the first token id to be transferred
     * quantity - the amount to be transferred
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero.
     * - `from` and `to` are never both zero.
     */
    function _afterTokenTransfers(
        address from,
        address to,
        uint256 startTokenId,
        uint256 quantity
    ) internal virtual {}
}

// File: contracts/ERC2981ContractWideRoyalties.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/utils/introspection/ERC165.sol';

import './ERC2981Base.sol';

/// @dev This is a contract used to add ERC2981 support to ERC721 and 1155
/// @dev This implementation has the same royalties for each and every tokens
abstract contract ERC2981ContractWideRoyalties is ERC2981Base {
    RoyaltyInfo private _royalties;

    /// @dev Sets token royalties
    /// @param recipient recipient of the royalties
    /// @param value percentage (using 2 decimals - 10000 = 100, 0 = 0)
    function _setRoyalties(address recipient, uint256 value) internal {
        _royalties = RoyaltyInfo(recipient, uint24(value));
    }

    /// @inheritdoc	IERC2981Royalties
    function royaltyInfo(uint256, uint256 value)
        external
        view
        override
        returns (address receiver, uint256 royaltyAmount)
    {
        RoyaltyInfo memory royalties = _royalties;
        receiver = royalties.recipient;
        royaltyAmount = (value * royalties.amount) / 10000;
    }
}

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



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

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

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

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

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

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

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

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

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

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

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

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

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

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

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

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



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

pragma solidity ^0.8.0;

import "../IERC721.sol";

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

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

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

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Enumerable is IERC721 {
    /**
     * @dev Returns the total amount of tokens stored by the contract.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
     * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
     */
    function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);

    /**
     * @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);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

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

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



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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/StorageSlot.sol)

pragma solidity ^0.8.0;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC1967 implementation slot:
 * ```
 * contract ERC1967 {
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly {
            r.slot := slot
        }
    }
}

// File: contracts/BitMaps.sol



// SPDX-License-Identifier: MIT
/**
   _____       ___     ___ __           ____  _ __      
  / ___/____  / (_)___/ (_) /___  __   / __ )(_) /______
  \__ \/ __ \/ / / __  / / __/ / / /  / __  / / __/ ___/
 ___/ / /_/ / / / /_/ / / /_/ /_/ /  / /_/ / / /_(__  ) 
/____/\____/_/_/\__,_/_/\__/\__, /  /_____/_/\__/____/  
                           /____/                        

- npm: https://www.npmjs.com/package/solidity-bits
- github: https://github.com/estarriolvetch/solidity-bits

 */
pragma solidity ^0.8.0;

import "./BitScan.sol";

/**
 * @dev This Library is a modified version of Openzeppelin's BitMaps library.
 * Functions of finding the index of the closest set bit from a given index are added.
 * The indexing of each bucket is modifed to count from the MSB to the LSB instead of from the LSB to the MSB.
 * The modification of indexing makes finding the closest previous set bit more efficient in gas usage.
*/

/**
 * @dev Library for managing uint256 to bool mapping in a compact and efficient way, providing the keys are sequential.
 * Largelly inspired by Uniswap's https://github.com/Uniswap/merkle-distributor/blob/master/contracts/MerkleDistributor.sol[merkle-distributor].
 */

library BitMaps {
    using BitScan for uint256;
    uint256 private constant MASK_INDEX_ZERO = (1 << 255);
    struct BitMap {
        mapping(uint256 => uint256) _data;
    }

    /**
     * @dev Returns whether the bit at `index` is set.
     */
    function get(BitMap storage bitmap, uint256 index) internal view returns (bool) {
        uint256 bucket = index >> 8;
        uint256 mask = MASK_INDEX_ZERO >> (index & 0xff);
        return bitmap._data[bucket] & mask != 0;
    }

    /**
     * @dev Sets the bit at `index` to the boolean `value`.
     */
    function setTo(
        BitMap storage bitmap,
        uint256 index,
        bool value
    ) internal {
        if (value) {
            set(bitmap, index);
        } else {
            unset(bitmap, index);
        }
    }

    /**
     * @dev Sets the bit at `index`.
     */
    function set(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = MASK_INDEX_ZERO >> (index & 0xff);
        bitmap._data[bucket] |= mask;
    }

    /**
     * @dev Unsets the bit at `index`.
     */
    function unset(BitMap storage bitmap, uint256 index) internal {
        uint256 bucket = index >> 8;
        uint256 mask = MASK_INDEX_ZERO >> (index & 0xff);
        bitmap._data[bucket] &= ~mask;
    }

    /**
     * @dev Find the closest index of the set bit before `index`.
     */
    function scanForward(BitMap storage bitmap, uint256 index) internal view returns (uint256) {
        uint256 bucket = index >> 8;

        // index within the bucket
        uint256 bucketIndex = (index & 0xff);

        // load a bitboard from the bitmap.
        uint256 bb = bitmap._data[bucket];

        // offset the bitboard to scan from `bucketIndex`.
        bb = bb >> (0xff ^ bucketIndex); // bb >> (255 - bucketIndex)
        
        if(bb > 0) {
            unchecked {
                return (bucket << 8) | (bucketIndex -  bb.bitScanForward256());    
            }
        } else {
            while(true) {
                require(bucket > 0, "BitMaps: The set bit before the index doesn't exist.");
                unchecked {
                    bucket--;
                }
                // No offset. Always scan from the least significiant bit now.
                bb = bitmap._data[bucket];
                
                if(bb > 0) {
                    unchecked {
                        return (bucket << 8) | (255 -  bb.bitScanForward256());    
                    }
                } 
            }
        }
    }

    function getBucket(BitMap storage bitmap, uint256 bucket) internal view returns (uint256) {
        return bitmap._data[bucket];
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

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

// File: contracts/BitScan.sol



// SPDX-License-Identifier: MIT
/**
   _____       ___     ___ __           ____  _ __      
  / ___/____  / (_)___/ (_) /___  __   / __ )(_) /______
  \__ \/ __ \/ / / __  / / __/ / / /  / __  / / __/ ___/
 ___/ / /_/ / / / /_/ / / /_/ /_/ /  / /_/ / / /_(__  ) 
/____/\____/_/_/\__,_/_/\__/\__, /  /_____/_/\__/____/  
                           /____/                        

- npm: https://www.npmjs.com/package/solidity-bits
- github: https://github.com/estarriolvetch/solidity-bits

 */

pragma solidity ^0.8.0;


library BitScan {
    uint256 constant private DEBRUIJN_256 = 0x818283848586878898a8b8c8d8e8f929395969799a9b9d9e9faaeb6bedeeff;
    bytes constant private LOOKUP_TABLE_256 = hex"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";

    /**
        @dev Isolate the least significant set bit.
     */ 
    function isolateLS1B256(uint256 bb) pure internal returns (uint256) {
        require(bb > 0);
        unchecked {
            return bb & (0 - bb);
        }
    } 

    /**
        @dev Isolate the most significant set bit.
     */ 
    function isolateMS1B256(uint256 bb) pure internal returns (uint256) {
        require(bb > 0);
        unchecked {
            bb |= bb >> 256;
            bb |= bb >> 128;
            bb |= bb >> 64;
            bb |= bb >> 32;
            bb |= bb >> 16;
            bb |= bb >> 8;
            bb |= bb >> 4;
            bb |= bb >> 2;
            bb |= bb >> 1;
            
            return (bb >> 1) + 1;
        }
    } 

    /**
        @dev Find the index of the lest significant set bit. (trailing zero count)
     */ 
    function bitScanForward256(uint256 bb) pure internal returns (uint8) {
        unchecked {
            return uint8(LOOKUP_TABLE_256[(isolateLS1B256(bb) * DEBRUIJN_256) >> 248]);
        }   
    }

    /**
        @dev Find the index of the most significant set bit.
     */ 
    function bitScanReverse256(uint256 bb) pure internal returns (uint8) {
        unchecked {
            return 255 - uint8(LOOKUP_TABLE_256[((isolateMS1B256(bb) * DEBRUIJN_256) >> 248)]);
        }   
    }

    function log2(uint256 bb) pure internal returns (uint8) {
        unchecked {
            return uint8(LOOKUP_TABLE_256[(isolateMS1B256(bb) * DEBRUIJN_256) >> 248]);
        } 
    }
}

// File: contracts/ERC2981Base.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/utils/introspection/ERC165.sol';

import './IERC2981Royalties.sol';

/// @dev This is a contract used to add ERC2981 support to ERC721 and 1155
abstract contract ERC2981Base is ERC165, IERC2981Royalties {
    struct RoyaltyInfo {
        address recipient;
        uint24 amount;
    }

    /// @inheritdoc	ERC165
    function supportsInterface(bytes4 interfaceId)
        public
        view
        virtual
        override
        returns (bool)
    {
        return
            interfaceId == type(IERC2981Royalties).interfaceId ||
            super.supportsInterface(interfaceId);
    }
}

// File: contracts/IERC2981Royalties.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @title IERC2981Royalties
/// @dev Interface for the ERC2981 - Token Royalty standard
interface IERC2981Royalties {
    /// @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 _value - 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 value sale price
    function royaltyInfo(uint256 _tokenId, uint256 _value)
        external
        view
        returns (address _receiver, uint256 _royaltyAmount);
}