// File: contracts/Rng.sol

//SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title A pseudo random number generator
 *
 * @dev This is not a true random number generator because smart contracts must be deterministic (every node a transaction goes to must produce the same result).
 *      True randomness requires an oracle which is both expensive in terms of gas and would take a critical part of the project off the chain.
 */
struct Rng {
    bytes32 state;
}

/**
 * @title A library for working with the Rng struct.
 *
 * @dev Rng cannot be a contract because then anyone could manipulate it by generating random numbers.
 */
library RngLibrary {
    /**
     * Creates a new Rng.
     */
    function newRng() internal view returns (Rng memory) {
        return Rng(getEntropy());
    }

    /**
     * Creates a pseudo-random value from the current block miner's address and sender.
     */
    function getEntropy() internal view returns (bytes32) {
        return keccak256(abi.encodePacked(block.coinbase, msg.sender));
    }

    /**
     * Generates a random uint256.
     */
    function generate(Rng memory self) internal view returns (uint256) {
        self.state = keccak256(abi.encodePacked(getEntropy(), self.state));
        return uint256(self.state);
    }

    /**
     * Generates a random uint256 from min to max inclusive.
     *
     * @dev This function is not subject to modulo bias.
     *      The chance that this function has to reroll is astronomically unlikely, but it can theoretically reroll forever.
     */
    function generate(Rng memory self, uint min, uint max) internal view returns (uint256) {
        require(min <= max, "min > max");

        uint delta = max - min;

        if (delta == 0) {
            return min;
        }

        return generate(self) % (delta + 1) + min;
    }
}

// File: contracts/Enums.sol


pragma solidity ^0.8.0;

enum RerollTrait {
    BgColor,
    Outfit,
    HandAccessory,
    Mouth,
    Eyes,
    HeadAccessory
}

enum Special {
    NONE,
    DEVIL,
    GHOST,
    HIPPIE,
    JOKER,
    PRISONER,
    SQUID_GAME,
    WHERES_WALDO,
    HAZMAT,
    ASTRONAUT
}

enum Dominant {
    SKELETON,
    VAMPIRE,
    MUMMY,
    GHOST,
    WITCH,
    FRANKENSTEIN,
    WEREWOLF,
    PUMPKINHEAD
}

enum Recessive {
    SKELETON,
    VAMPIRE,
    MUMMY,
    GHOST,
    DEVIL,
    KONG
}

enum BgColor {
    DARK_BLUE,
    GRAY,
    LIGHT_BLUE,
    ORANGE,
    PINK,
    PURPLE,
    RED,
    TAN,
    TEAL,
    GREEN,
    RAINBOW
}

enum Outfit {
    WHITE_SHORTS,
    PINK_SHORTS,
    GRAY_PANTS,
    WHITE_AND_BLUE,
    PURPLE_SHORTS,
    PINK_AND_PURPLE,
    BROWN_AND_WHITE,
    BROWN_AND_BLUE,
    BLUE_SHORTS,
    BLUE_AND_WHITE,
    UNDERGARMENTS,
    LOUNGEWEAR,
    HOBO,
    SPORTS_JERSEY,
    GOLD_CHAIN,
    PAJAMAS,
    OVERALLS,
    SPEEDO,
    NINJA_SUIT,
    KARATE_UNIFORM,
    NONE,
    LUMBERJACK,
    PRIEST,
    TUX,
    SKELETON,
    CAMO,
    ARMOR
}

enum HandAccessory {
    NONE,
    BLOODY_KNIFE,
    BOW_AND_ARROW,
    SWORD,
    PITCHFORK,
    WAND,
    SPIKED_BASEBALL_BAT,
    ENERGY_DRINK,
    NINJA_STARS,
    NUNCHUCKS,
    POOP,
    FLAMETHROWER,
    HOOKS,
    WEIGHTS,
    SKULL,
    BRAIN
}

enum Mouth {
    NONE,
    HAPPY,
    MAD,
    SMILE,
    FANGS,
    HAPPY_FANGS,
    MAD_FANGS,
    SMILE_FANGS,
    SINGLE_TOOTH,
    DIRTY_TEETH,
    SMILE_DIRTY_TEETH,
    MAD_DIRTY_TEETH,
    BLOODY_FANGS,
    BLACK_MASK,
    HAPPY_BUCK_TEETH,
    HAPPY_SINGLE_TOOTH,
    MAD_SINGLE_TOOTH,
    SMILE_SINGLE_TOOTH,
    BREATHING_FIRE,
    GOLD_GRILLS,
    KISS,
    SMOKING_JOINT
}

enum Eyes {
    NONE,
    BLACK_EYE,
    BLACKOUT,
    BLEEDING,
    BLOODSHOT,
    WATERY,
    WHITE,
    BIGGER_BLACK_EYES,
    BIGGER_BLEEDING,
    BIGGER_WATERY,
    SMALLER_BLACK_EYES,
    SMALLER_BLEEDING,
    SMALLER_BLOODSHOT,
    SMALLER_WATERY,
    SMALLER,
    SUNGLASSES,
    EYE_PATCH,
    VR_HEADSET,
    DEAD,
    _3D_GLASSES,
    HEART_EYES,
    LASER_GLASSES,
    NINJA_MASK,
    LASER_EYES
}

enum HeadAccessory {
    NONE,
    BUCKET_HAT,
    FLOWER,
    SPORTS_HEADBAND,
    CHEF_HAT,
    BLUE_DURAG,
    RED_DURAG,
    SPIKY_HAIR,
    BONES,
    RICE_HAT,
    BEANIE_CAP,
    SANTA_HAT,
    HEAD_WOUND,
    HEADPHONES,
    GOLD_STUDS,
    WIZARD_HAT,
    LONG_HAIR,
    AIR_PODS,
    WHITE_PARTY_HAT,
    BLUE_PARTY_HAT,
    RED_PARTY_HAT,
    GREEN_PARTY_HAT,
    YELLOW_PARTY_HAT,
    PURPLE_PARTY_HAT,
    PIRATE_HAT,
    KING_CROWN,
    JOKER_HAT,
    DEVIL_HORNS,
    BRAINS
}

library Enums {
    function toString(Special v) external pure returns (string memory) {
        if (v == Special.NONE) {
            return "";
        }
    
        if (v == Special.DEVIL) {
            return "Devil";
        }
    
        if (v == Special.GHOST) {
            return "Ghost";
        }
    
        if (v == Special.HIPPIE) {
            return "Hippie";
        }
    
        if (v == Special.JOKER) {
            return "Society";
        }
    
        if (v == Special.PRISONER) {
            return "Prisoner";
        }
    
        if (v == Special.SQUID_GAME) {
            return "Squid Girl";
        }
    
        if (v == Special.WHERES_WALDO) {
            return "Where's Waldo?";
        }
    
        if (v == Special.HAZMAT) {
            return "Hazmat";
        }
    
        if (v == Special.ASTRONAUT) {
            return "Astronaut";
        }
        revert("invalid special");
    }
    
    function toString(Dominant v) external pure returns (string memory) {
        if (v == Dominant.SKELETON) {
            return "Skeleton";
        }
    
        if (v == Dominant.VAMPIRE) {
            return "Vampire";
        }
    
        if (v == Dominant.MUMMY) {
            return "Mummy";
        }
    
        if (v == Dominant.GHOST) {
            return "Ghost";
        }
    
        if (v == Dominant.WITCH) {
            return "Witch";
        }
    
        if (v == Dominant.FRANKENSTEIN) {
            return "Frankenstein";
        }
    
        if (v == Dominant.WEREWOLF) {
            return "Werewolf";
        }
    
        if (v == Dominant.PUMPKINHEAD) {
            return "Pumpkinhead";
        }
        revert("invalid dominant");
    }
    
    function toString(Recessive v) external pure returns (string memory) {
        if (v == Recessive.SKELETON) {
            return "Skeleton";
        }
    
        if (v == Recessive.VAMPIRE) {
            return "Vampire";
        }
    
        if (v == Recessive.MUMMY) {
            return "Mummy";
        }
    
        if (v == Recessive.GHOST) {
            return "Ghost";
        }
    
        if (v == Recessive.DEVIL) {
            return "Devil";
        }
    
        if (v == Recessive.KONG) {
            return "Kong";
        }
        revert("invalid recessive");
    }
    
    function toString(BgColor v) external pure returns (string memory) {
        if (v == BgColor.DARK_BLUE) {
            return "Dark Blue";
        }
    
        if (v == BgColor.GRAY) {
            return "Gray";
        }
    
        if (v == BgColor.LIGHT_BLUE) {
            return "Light Blue";
        }
    
        if (v == BgColor.ORANGE) {
            return "Orange";
        }
    
        if (v == BgColor.PINK) {
            return "Pink";
        }
    
        if (v == BgColor.PURPLE) {
            return "Purple";
        }
    
        if (v == BgColor.RED) {
            return "Red";
        }
    
        if (v == BgColor.TAN) {
            return "Tan";
        }
    
        if (v == BgColor.TEAL) {
            return "Teal";
        }
    
        if (v == BgColor.GREEN) {
            return "Green";
        }
    
        if (v == BgColor.RAINBOW) {
            return "Rainbow";
        }
        revert("invalid bgcolor");
    }
    
    function toString(Outfit v) external pure returns (string memory) {
        if (v == Outfit.WHITE_SHORTS) {
            return "White Shorts";
        }
    
        if (v == Outfit.PINK_SHORTS) {
            return "Pink Shorts";
        }
    
        if (v == Outfit.GRAY_PANTS) {
            return "Gray Pants";
        }
    
        if (v == Outfit.WHITE_AND_BLUE) {
            return "White and Blue";
        }
    
        if (v == Outfit.PURPLE_SHORTS) {
            return "Purple Shorts";
        }
    
        if (v == Outfit.PINK_AND_PURPLE) {
            return "Pink and Purple";
        }
    
        if (v == Outfit.BROWN_AND_WHITE) {
            return "Brown and White";
        }
    
        if (v == Outfit.BROWN_AND_BLUE) {
            return "Brown and Blue";
        }
    
        if (v == Outfit.BLUE_SHORTS) {
            return "Blue Shorts";
        }
    
        if (v == Outfit.BLUE_AND_WHITE) {
            return "Blue and White";
        }
    
        if (v == Outfit.UNDERGARMENTS) {
            return "Undergarments";
        }
    
        if (v == Outfit.LOUNGEWEAR) {
            return "Loungewear";
        }
    
        if (v == Outfit.HOBO) {
            return "Hobo";
        }
    
        if (v == Outfit.SPORTS_JERSEY) {
            return "Sports Jersey";
        }
    
        if (v == Outfit.GOLD_CHAIN) {
            return "Gold Chain";
        }
    
        if (v == Outfit.PAJAMAS) {
            return "Pajamas";
        }
    
        if (v == Outfit.OVERALLS) {
            return "Overalls";
        }
    
        if (v == Outfit.SPEEDO) {
            return "Speedo";
        }
    
        if (v == Outfit.NINJA_SUIT) {
            return "Ninja Suit";
        }
    
        if (v == Outfit.KARATE_UNIFORM) {
            return "Karate Uniform";
        }
    
        if (v == Outfit.NONE) {
            return "";
        }
    
        if (v == Outfit.LUMBERJACK) {
            return "Lumberjack";
        }
    
        if (v == Outfit.PRIEST) {
            return "Priest";
        }
    
        if (v == Outfit.TUX) {
            return "Tux";
        }
    
        if (v == Outfit.SKELETON) {
            return "Skeleton";
        }
    
        if (v == Outfit.CAMO) {
            return "Camo";
        }
    
        if (v == Outfit.ARMOR) {
            return "Armor";
        }
        revert("invalid outfit");
    }
    
    function toString(HandAccessory v) external pure returns (string memory) {
        if (v == HandAccessory.NONE) {
            return "";
        }
    
        if (v == HandAccessory.BLOODY_KNIFE) {
            return "Bloody Knife";
        }
    
        if (v == HandAccessory.BOW_AND_ARROW) {
            return "Bow and Arrow";
        }
    
        if (v == HandAccessory.SWORD) {
            return "Sword";
        }
    
        if (v == HandAccessory.PITCHFORK) {
            return "Pitchfork";
        }
    
        if (v == HandAccessory.WAND) {
            return "Wand";
        }
    
        if (v == HandAccessory.SPIKED_BASEBALL_BAT) {
            return "Spiked Baseball Bat";
        }
    
        if (v == HandAccessory.ENERGY_DRINK) {
            return "Energy Drink";
        }
    
        if (v == HandAccessory.NINJA_STARS) {
            return "Ninja Stars";
        }
    
        if (v == HandAccessory.NUNCHUCKS) {
            return "Nunchucks";
        }
    
        if (v == HandAccessory.POOP) {
            return "Poop";
        }
    
        if (v == HandAccessory.FLAMETHROWER) {
            return "Flamethrower";
        }
    
        if (v == HandAccessory.HOOKS) {
            return "Hooks";
        }
    
        if (v == HandAccessory.WEIGHTS) {
            return "Weights";
        }
    
        if (v == HandAccessory.SKULL) {
            return "Skull";
        }
    
        if (v == HandAccessory.BRAIN) {
            return "Brain";
        }
        revert("invalid handaccessory");
    }
    
    function toString(Mouth v) external pure returns (string memory) {
        if (v == Mouth.NONE) {
            return "";
        }
    
        if (v == Mouth.HAPPY) {
            return "Happy";
        }
    
        if (v == Mouth.MAD) {
            return "Mad";
        }
    
        if (v == Mouth.SMILE) {
            return "Smile";
        }
    
        if (v == Mouth.FANGS) {
            return "Fangs";
        }
    
        if (v == Mouth.HAPPY_FANGS) {
            return "Happy Fangs";
        }
    
        if (v == Mouth.MAD_FANGS) {
            return "Mad Fangs";
        }
    
        if (v == Mouth.SMILE_FANGS) {
            return "Smile Fangs";
        }
    
        if (v == Mouth.SINGLE_TOOTH) {
            return "Single Tooth";
        }
    
        if (v == Mouth.DIRTY_TEETH) {
            return "Dirty Teeth";
        }
    
        if (v == Mouth.SMILE_DIRTY_TEETH) {
            return "Smile Dirty Teeth";
        }
    
        if (v == Mouth.MAD_DIRTY_TEETH) {
            return "Mad Dirty Teeth";
        }
    
        if (v == Mouth.BLOODY_FANGS) {
            return "Bloody Fangs";
        }
    
        if (v == Mouth.BLACK_MASK) {
            return "Black Mask";
        }
    
        if (v == Mouth.HAPPY_BUCK_TEETH) {
            return "Happy Buck Teeth";
        }
    
        if (v == Mouth.HAPPY_SINGLE_TOOTH) {
            return "Happy Single Tooth";
        }
    
        if (v == Mouth.MAD_SINGLE_TOOTH) {
            return "Mad Single Tooth";
        }
    
        if (v == Mouth.SMILE_SINGLE_TOOTH) {
            return "Smile Single Tooth";
        }
    
        if (v == Mouth.BREATHING_FIRE) {
            return "Breathing Fire";
        }
    
        if (v == Mouth.GOLD_GRILLS) {
            return "Gold Grills";
        }
    
        if (v == Mouth.KISS) {
            return "Kiss";
        }
    
        if (v == Mouth.SMOKING_JOINT) {
            return "Smoking Joint";
        }
        revert("invalid mouth");
    }
    
    function toString(Eyes v) external pure returns (string memory) {
        if (v == Eyes.NONE) {
            return "";
        }
    
        if (v == Eyes.BLACK_EYE) {
            return "Black Eye";
        }
    
        if (v == Eyes.BLACKOUT) {
            return "Blackout";
        }
    
        if (v == Eyes.BLEEDING) {
            return "Bleeding";
        }
    
        if (v == Eyes.BLOODSHOT) {
            return "Bloodshot";
        }
    
        if (v == Eyes.WATERY) {
            return "Watery";
        }
    
        if (v == Eyes.WHITE) {
            return "White";
        }
    
        if (v == Eyes.BIGGER_BLACK_EYES) {
            return "Bigger Black Eyes";
        }
    
        if (v == Eyes.BIGGER_BLEEDING) {
            return "Bigger Bleeding";
        }
    
        if (v == Eyes.BIGGER_WATERY) {
            return "Bigger Watery";
        }
    
        if (v == Eyes.SMALLER_BLACK_EYES) {
            return "Smaller Black Eyes";
        }
    
        if (v == Eyes.SMALLER_BLEEDING) {
            return "Smaller Bleeding";
        }
    
        if (v == Eyes.SMALLER_BLOODSHOT) {
            return "Smaller Bloodshot";
        }
    
        if (v == Eyes.SMALLER_WATERY) {
            return "Smaller Watery";
        }
    
        if (v == Eyes.SMALLER) {
            return "Smaller";
        }
    
        if (v == Eyes.SUNGLASSES) {
            return "Sunglasses";
        }
    
        if (v == Eyes.EYE_PATCH) {
            return "Eye Patch";
        }
    
        if (v == Eyes.VR_HEADSET) {
            return "VR Headset";
        }
    
        if (v == Eyes.DEAD) {
            return "Dead";
        }
    
        if (v == Eyes._3D_GLASSES) {
            return "3D Glasses";
        }
    
        if (v == Eyes.HEART_EYES) {
            return "Heart Eyes";
        }
    
        if (v == Eyes.LASER_GLASSES) {
            return "Laser Glasses";
        }
    
        if (v == Eyes.NINJA_MASK) {
            return "Ninja Mask";
        }
    
        if (v == Eyes.LASER_EYES) {
            return "Laser Eyes";
        }
        revert("invalid eyes");
    }
    
    function toString(HeadAccessory v) external pure returns (string memory) {
        if (v == HeadAccessory.NONE) {
            return "";
        }
    
        if (v == HeadAccessory.BUCKET_HAT) {
            return "Bucket Hat";
        }
    
        if (v == HeadAccessory.FLOWER) {
            return "Flower";
        }
    
        if (v == HeadAccessory.SPORTS_HEADBAND) {
            return "Sports Headband";
        }
    
        if (v == HeadAccessory.CHEF_HAT) {
            return "Chef Hat";
        }
    
        if (v == HeadAccessory.BLUE_DURAG) {
            return "Blue Durag";
        }
    
        if (v == HeadAccessory.RED_DURAG) {
            return "Red Durag";
        }
    
        if (v == HeadAccessory.SPIKY_HAIR) {
            return "Spiky Hair";
        }
    
        if (v == HeadAccessory.BONES) {
            return "Bones";
        }
    
        if (v == HeadAccessory.RICE_HAT) {
            return "Rice Hat";
        }
    
        if (v == HeadAccessory.BEANIE_CAP) {
            return "Beanie Cap";
        }
    
        if (v == HeadAccessory.SANTA_HAT) {
            return "Santa Hat";
        }
    
        if (v == HeadAccessory.HEAD_WOUND) {
            return "Head Wound";
        }
    
        if (v == HeadAccessory.HEADPHONES) {
            return "Headphones";
        }
    
        if (v == HeadAccessory.GOLD_STUDS) {
            return "Gold Studs";
        }
    
        if (v == HeadAccessory.WIZARD_HAT) {
            return "Wizard Hat";
        }
    
        if (v == HeadAccessory.LONG_HAIR) {
            return "Long Hair";
        }
    
        if (v == HeadAccessory.AIR_PODS) {
            return "Air Pods";
        }
    
        if (v == HeadAccessory.WHITE_PARTY_HAT) {
            return "White Party Hat";
        }
    
        if (v == HeadAccessory.BLUE_PARTY_HAT) {
            return "Blue Party Hat";
        }
    
        if (v == HeadAccessory.RED_PARTY_HAT) {
            return "Red Party Hat";
        }
    
        if (v == HeadAccessory.GREEN_PARTY_HAT) {
            return "Green Party Hat";
        }
    
        if (v == HeadAccessory.YELLOW_PARTY_HAT) {
            return "Yellow Party Hat";
        }
    
        if (v == HeadAccessory.PURPLE_PARTY_HAT) {
            return "Purple Party Hat";
        }
    
        if (v == HeadAccessory.PIRATE_HAT) {
            return "Pirate Hat";
        }
    
        if (v == HeadAccessory.KING_CROWN) {
            return "King Crown";
        }
    
        if (v == HeadAccessory.JOKER_HAT) {
            return "Joker Hat";
        }
    
        if (v == HeadAccessory.DEVIL_HORNS) {
            return "Devil Horns";
        }
    
        if (v == HeadAccessory.BRAINS) {
            return "Brains";
        }
        revert("invalid headaccessory");
    }
}

// File: contracts/BitMonster.sol


pragma solidity ^0.8.0;


struct BitMonster {
    bool genesis;
    bool superYield;
    Special special;
    Dominant dominant;
    Recessive recessive;
    BgColor bgColor;
    Outfit outfit;
    HandAccessory handAccessory;
    Mouth mouth;
    Eyes eyes;
    HeadAccessory headAccessory;
}

// File: @openzeppelin/contracts/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: @openzeppelin/contracts/token/ERC721/IERC721.sol



pragma solidity ^0.8.0;


/**
 * @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/extensions/IERC721Enumerable.sol



pragma solidity ^0.8.0;


/**
 * @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 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);
}

// File: contracts/IBitMonsters.sol


pragma solidity ^0.8.0;



interface IBitMonsters is IERC721Enumerable {
    function getBitMonster(uint256 tokenId) external view returns (BitMonster memory);
    function setBitMonster(uint256 tokenId, BitMonster memory bm) external;
    function createBitMonster(BitMonster memory bm, address owner) external;
    function isAdmin(address addr) external view returns (bool);
}
// File: @openzeppelin/contracts/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/access/Ownable.sol



pragma solidity ^0.8.0;


/**
 * @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() {
        _setOwner(_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 {
        _setOwner(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");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: contracts/BitMonstersAddon.sol


pragma solidity ^0.8.0;



/**
 * @title A contract should inherit this if it provides functionality for the Bit Monsters contract.
 */
abstract contract BitMonstersAddon is Ownable {
    IBitMonsters internal bitMonsters;

    modifier onlyAdmin() {
        require(bitMonsters.isAdmin(msg.sender), "admins only");
        _;
    }

    modifier ownsToken(uint tokenId) {
        require(bitMonsters.ownerOf(tokenId) == msg.sender, "you don't own this shit");
        _;
    }

    /**
     * @notice This must be called before the Brainz contract can be used.
     *
     * @dev Within the BitMonsters contract, call initializeBrainz().
     */
    function setBitMonstersContract(IBitMonsters _contract) external onlyOwner {
        bitMonsters = _contract;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



pragma solidity ^0.8.0;


/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



pragma solidity ^0.8.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol



pragma solidity ^0.8.0;



/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract ERC20Burnable is Context, ERC20 {
    /**
     * @dev Destroys `amount` tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 amount) public virtual {
        _burn(_msgSender(), amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
     * allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for ``accounts``'s tokens of at least
     * `amount`.
     */
    function burnFrom(address account, uint256 amount) public virtual {
        uint256 currentAllowance = allowance(account, _msgSender());
        require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
        unchecked {
            _approve(account, _msgSender(), currentAllowance - amount);
        }
        _burn(account, amount);
    }
}

// File: contracts/Brainz.sol


pragma solidity ^0.8.0;









// shamelessly "inspired by" the anonymice cheeth contract

/**
 * @title The contract for the Brainz token and staking. At the moment, these can only be obtained by staking Bit Monsters.
 */
contract Brainz is ERC20Burnable, BitMonstersAddon {
    using RngLibrary for Rng;

    mapping (uint => uint) public tokenIdToTimestamp;
    Rng private rng = RngLibrary.newRng();

    constructor() ERC20("Brainz", "BRAINZ") {
    }

    function adminMint(address addr, uint256 count) external onlyAdmin {
        _mint(addr, count * 1 ether);
    }

    function adminBurn(address addr, uint256 count) external onlyAdmin {
        _burn(addr, count * 1 ether);
    }

    /**
     * Claims all Brainz from all staked Bit Monsters the caller owns.
     */
    function claimBrainz() external {
        uint count = bitMonsters.balanceOf(msg.sender);
        uint total = 0;

        for (uint i = 0; i < count; ++i) {
            uint tokenId = bitMonsters.tokenOfOwnerByIndex(msg.sender, i);
            uint rewards = calculateRewards(tokenId);
            if (rewards > 0) {
                tokenIdToTimestamp[tokenId] = block.timestamp - ((block.timestamp - tokenIdToTimestamp[tokenId]) % 86400);
            }
            total += rewards;
        }

        _mint(msg.sender, total);
    }

    function rewardRate(BitMonster memory m) public pure returns (uint) {
        return ((m.genesis ? 2 : 1) * (m.special != Special.NONE ? 2 : 1) + (m.superYield ? 1 : 0)) * 1 ether;
    }

    /**
     * Returns the amount of pending Brainz the caller can currently claim.
     */
    function calculateRewards(uint tokenId) public view returns (uint) {
        BitMonster memory m = bitMonsters.getBitMonster(tokenId);
        uint nDays = (block.timestamp - tokenIdToTimestamp[tokenId]) / 86400;

        return rewardRate(m) * nDays;
    }

    /**
     * Tracks the Bit Monster with the given tokenId for reward calculation.
     */
    function register(uint tokenId) external onlyAdmin {
        require(tokenIdToTimestamp[tokenId] == 0, "already staked");
        tokenIdToTimestamp[tokenId] = block.timestamp;
    }

    /**
     * Stake your Brainz a-la OSRS Duel Arena.
     *
     * 50% chance of multiplying your Brainz by 1.9x rounded up.
     * 50% chance of losing everything you stake.
     */
    function stake(uint count) external returns (bool won) {
        require(count > 0, "Must stake at least one BRAINZ");
        require(balanceOf(msg.sender) >= count, "You don't have that many tokens");

        Rng memory rn = rng;

        if (rn.generate(0, 1) == 0) {
            _mint(msg.sender, (count - count / 10) * 1 ether);
            won = true;
        }
        else {
            _burn(msg.sender, count * 1 ether);
            won = false;
        }

        rng = rn;
    }
}