// File: /contracts/SpellBook.sol



// SPDX-License-Identifier: MIT


pragma solidity 0.8.7;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "./Interfaces/ICaster.sol";
import "./Interfaces/ICurse.sol";


contract SpellBook is AccessControl, Pausable {
    using Address for address;
    using SafeERC20 for IERC20;

    struct IEffectData {
        uint256 countdown;
        uint8 effectId;
    }

    struct ISpellConfig {
        uint256 costBase;
        uint256 costDiscountPerLvl;

        uint256 cooldownBase;
        uint256 cooldownDiscountPerLvl;

        uint256 effectBase;
        uint256 effectMultiplierPerLvl;

        uint8 minLvlToCast;
        uint8 xpRewardPerCast;
    }
    // Generic constants
    uint8 public constant MAX_LEVEL = 3;
    // ACL constants
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");

    // Spell constants
    uint8 public constant SPELL_FREEZE = 0;
    uint8 public constant SPELL_PROTECT = 1;
    uint8 public constant SPELL_DISPEL = 2;
    uint8 public constant SPELL_MINT = 3;
    uint8 public constant SPELL_BURN = 4;
    uint8 public constant SPELL_STEAL = 5;
    uint8 public constant SPELL_INFLATE = 6;
    uint8 public constant SPELL_DEFLATE = 7;
    uint8 public constant SPELL_DOMINATE = 8;

    uint8 public constant NUM_OF_SPELLS = 9;

    // Effect constants
    uint8 public constant EFFECT_COOLDOWN = 0;
    uint8 public constant EFFECT_FREEZE = 1;
    uint8 public constant EFFECT_PROTECT = 2;
    uint8 public constant EFFECT_STOLEN = 3;
    uint8 public constant EFFECT_IMMUNE = 4; // Only for dev, to protect UniswapPair and contract address

    uint8 public constant EFFECT_TOTAL = 5;

    // Price selector
    uint8 public constant PRICE_SPELLBOOK_ETH = 0;
    uint8 public constant PRICE_SPELLBOOK_CURSE = 1;

    // Generic config variables
    address public _feeWallet;
    address public _curseBeneficiary;

    uint256 public refreshPrice;
    
    uint256[MAX_LEVEL] public lvlUpPrice;
    uint256[MAX_LEVEL] public lvlUpXp;

    uint256[2] public baseSpellBookPrice;

    // Spell config variables
    ISpellConfig[NUM_OF_SPELLS] public spellConfig;

    IERC20 public CURSE;
    ICaster public CASTER;

    event SpellConfigUpdated(uint8 indexed spellId);
    event SpellCasted(address indexed caster, address indexed target, uint8 indexed spellId, uint256 effect);
    event LevelUp(address indexed caster, uint8 newLevel);
    event SpellBookBought(address indexed owner);

    constructor(address casterData) {
        address _owner = _msgSender();
        _grantRole(DEFAULT_ADMIN_ROLE, _owner);
        _grantRole(ADMIN_ROLE, _owner);

        CASTER = ICaster(casterData);

        _feeWallet = _owner;
        // Default CURSE holder is spellbook
        _curseBeneficiary = address(this);

        // Default spellbook price
        baseSpellBookPrice[PRICE_SPELLBOOK_ETH] = 0.025 ether; // 0.025 ETHER
        baseSpellBookPrice[PRICE_SPELLBOOK_CURSE] = 500 ether; // 500 CURSE

        // Default level up prices
        lvlUpPrice[0] = 0.025 ether; // lvl 0 -> 1
        lvlUpPrice[1] = 0.05 ether; // lvl 1 -> 2
        lvlUpPrice[2] = 0.075 ether; // lvl 2 -> 3

        // Default level up XP required
        lvlUpXp[0] = 100; // lvl 0 -> 1
        lvlUpXp[1] = 200; // lvl 1 -> 2
        lvlUpXp[2] = 400; // lvl 2 -> 3

        // Default cooldown refresh price
        refreshPrice = 0.015 ether;
    }
    /**
      * Modifiers
     */
    modifier onlySpellBook(address caster) {
        require(hasSpellBook(caster), "Spellbook missing");
        _;
    }
    
    modifier notProtected(address target) {
        require(!isProtected(target), "Target protected");
        _;
    }

    modifier noCooldown(address caster) {
        require(!hasCooldown(caster), "On cooldown");
        _;
    }

    /**
      Internal helpers
     */
    function getCooldown(ISpellConfig memory spell, uint8 level) internal pure returns (uint256) {
        uint256 discount = (uint256(level) * spell.cooldownDiscountPerLvl);
        return spell.cooldownBase > discount? spell.cooldownBase - discount : spell.cooldownBase;
    }

    function getEffect(ISpellConfig memory spell, uint8 level) internal pure returns  (uint256) {
        uint256 multiplier = (uint256(level) * spell.effectMultiplierPerLvl);
        return spell.effectBase + multiplier;
    }
    
    function getPrice(ISpellConfig memory spell, uint8 level) internal pure returns (uint256){
        uint256 discount = (uint256(level) * spell.costDiscountPerLvl);
        return spell.costBase > discount? spell.costBase - discount : spell.costBase;
    }

    function setCooldown(address caster, ISpellConfig memory spell, uint8 level) internal returns (uint256) {
        uint256 duration = getCooldown(spell, level);
        CASTER.setEffect(caster, EFFECT_COOLDOWN, duration);
        return duration;
    }

    function setEffect(address caster, uint8 effectId, ISpellConfig memory spell, uint8 level) internal returns (uint256) {
        uint256 duration = getEffect(spell, level);
        CASTER.setEffect(caster, effectId, duration);
        return duration;
    }

    function ensureCurseBalance(uint256 price, address caster) internal view {
        if (price > 0) {
            require(CURSE.balanceOf(caster) >= price, "Insufficient balance");
        }
    }

    function takeCurseFee(uint256 price, address caster) internal {
        if (price > 0) {
            require(CURSE.balanceOf(caster) >= price, "Insufficient balance");
            // Transfer the amount
            CURSE.safeTransferFrom(caster, _curseBeneficiary, price);
        }
    }

    function clearEffect(address caster, uint8 effectId) internal {
        if (CASTER.hasEffect(caster, effectId)) CASTER.clearEffect(caster, effectId);
    }

    /**
      * Management functions
     */
    
    function pause() public onlyRole(ADMIN_ROLE) whenNotPaused {
        _pause();
    }

    function unpause() public onlyRole(ADMIN_ROLE) whenPaused {
        _unpause();
    }

    function setCurseToken(address addr) external onlyRole(ADMIN_ROLE) {
        CURSE = IERC20(addr);
        setPermanentProtection(addr, true);
    }
    
    function promoteAdmin(address newAdmin) public onlyRole(ADMIN_ROLE) {
        _grantRole(ADMIN_ROLE, newAdmin);
        //_setRoleAdmin(DEFAULT_ADMIN_ROLE, newAdmin);
        // TODO: remove the old admin
        setPermanentProtection(newAdmin, true);
    }

    function setLvlUpConfig(uint256[MAX_LEVEL] memory price, uint256[MAX_LEVEL] memory xpRequired) external onlyRole(ADMIN_ROLE) {
        lvlUpPrice = price;
        lvlUpXp = xpRequired;
    }

    function setFeeWallet(address addr) external onlyRole(ADMIN_ROLE) {
        _feeWallet = addr;
        
    }

    function setCurseBeneficiary(address addr) external onlyRole(ADMIN_ROLE) {
        _curseBeneficiary = addr;
    }

    function setSpellConfig(
        uint8 spellId,
        uint256 costBase,
        uint256 costDiscountPerLvl,
        uint256 cooldownBase,
        uint256 cooldownDiscountPerLvl,
        uint256 effectBase,
        uint256 effectMultiplierPerLvl,
        uint8 minLvlToCast,
        uint8 xpRewardPerCast
    ) public onlyRole(ADMIN_ROLE) {
        require(spellId < NUM_OF_SPELLS, "Out of range");

        spellConfig[spellId].costBase = costBase;
        spellConfig[spellId].costDiscountPerLvl = costDiscountPerLvl;
        spellConfig[spellId].cooldownBase = cooldownBase;
        spellConfig[spellId].cooldownDiscountPerLvl = cooldownDiscountPerLvl;
        spellConfig[spellId].effectBase = effectBase;
        spellConfig[spellId].effectMultiplierPerLvl = effectMultiplierPerLvl;
        spellConfig[spellId].minLvlToCast = minLvlToCast;
        spellConfig[spellId].xpRewardPerCast = xpRewardPerCast;

        emit SpellConfigUpdated(spellId);
    }

    function setSpellBookBasePrice(uint256 ethPrice, uint256 cursePrice) external onlyRole(ADMIN_ROLE) {
        baseSpellBookPrice[PRICE_SPELLBOOK_ETH] = ethPrice;
        baseSpellBookPrice[PRICE_SPELLBOOK_CURSE] = cursePrice;
    }

    function setRefreshPrice(uint256 price) external onlyRole(ADMIN_ROLE) {
        refreshPrice = price;
    }

    function setPermanentProtection(address addr, bool enabled) public onlyRole(ADMIN_ROLE) {
        if (enabled) {
            // Permanent protection is ~10 year
            CASTER.setEffect(addr, EFFECT_IMMUNE, 315360000);
        } else {
            CASTER.clearEffect(addr, EFFECT_IMMUNE);
        }

    }

    function sendEth() external {
        payable(_feeWallet).transfer(address(this).balance);
    }

    function sendCurse(address receiver) external onlyRole(ADMIN_ROLE) {   
        require(receiver != address(this), "Invalid receiver");
        uint256 balance = CURSE.balanceOf(address(this));
        if (balance > 0) {
            CURSE.transfer(receiver, balance);
        }
    }



    /**
      * Public getter functions
     */

    function totalSpells() public pure returns (uint8) {
        return NUM_OF_SPELLS;
    }

    function canLevelUp(address caster) public view returns (bool) {
        ICaster.SpellBookData memory book = CASTER.get(caster);
        uint8 level = CASTER.getLevel(caster);
        if (
            hasSpellBook(caster) &&
            level < MAX_LEVEL &&
            book.currentXp >= lvlUpXp[level]
        ) {
            return true;
        }
        return false;
    }

    function getLevel(address caster) public view returns (uint8) {
        return CASTER.getLevel(caster);
    }

    function getLevelUpPriceXp(address caster) public view returns (uint256, uint256) {
        uint8 level = CASTER.getLevel(caster);
        uint8 correctedLevel = level < MAX_LEVEL? level : level - 1;
        return (
            lvlUpPrice[correctedLevel],
            lvlUpXp[correctedLevel]
        );
    }

    function getSpell(address caster, uint8 spellId) public view returns (
        uint256 cost,
        uint256 cooldown,
        uint256 effect,
        uint256 xpReward,
        bool canCast
    ) {
        ISpellConfig memory spell = spellConfig[spellId];
        uint8 level = CASTER.getLevel(caster);

        cost = getPrice(spell, level);
        cooldown = getCooldown(spell, level);
        effect = getEffect(spell, level);
        xpReward = spell.xpRewardPerCast;
        canCast = level >= spell.minLvlToCast;
    }

    function hasSpellBook(address caster) public view returns (bool) {
        ICaster.SpellBookData memory book = CASTER.get(caster);
        return book.createdAt > 0;
    }

    function getSpellBook(address caster) external view returns (
        uint256 currentXp,
        uint256 createdAt,
        uint8 level
    ) {
        ICaster.SpellBookData memory book = CASTER.get(caster);

        currentXp = book.currentXp;
        createdAt = book.createdAt;
        level = book.level;
    }
    
    /**
      Public setter
     */

    function buySpellBookEth() external payable whenNotPaused {
        address caster = _msgSender();
        require(!hasSpellBook(caster), "Already have");
        require(msg.value >= baseSpellBookPrice[PRICE_SPELLBOOK_ETH], "SB: insufficient amount");        
        // Create the new SpellBook
        CASTER.create(caster);

        emit SpellBookBought(caster);
        
    }
    
    function buySpellBookCurse() external whenNotPaused {
        address caster = _msgSender();
        require(!hasSpellBook(caster), "Already have");
        uint256 price = baseSpellBookPrice[PRICE_SPELLBOOK_CURSE];

        if (price > 0) {
            require(CURSE.balanceOf(caster) >= price, "Insufficient balance");
            // Transfer the amount
            CURSE.safeTransferFrom(caster, _curseBeneficiary, price);
        }
        // Create the new SpellBook
        CASTER.create(caster);
        
        emit SpellBookBought(caster);
    }

    function levelUp() external payable onlySpellBook(_msgSender()) whenNotPaused {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);

        require(canLevelUp(caster), "Cannot level up");        
        (uint256 price,) = getLevelUpPriceXp(caster);
        require(msg.value >= price, "Insufficient amount");
        // XP is alredy check in canLevelUp, so it has to be greater or equal with the required XP level, not possible to overflow
        uint8 newLevel = book.level + 1;
        CASTER.setXp(caster, book.currentXp - lvlUpXp[book.level]);
        CASTER.setLevel(caster, newLevel);

        emit LevelUp(caster, newLevel);
    }

    function refresh() external payable onlySpellBook(_msgSender()) whenNotPaused {
        address caster = _msgSender();
        require(hasCooldown(caster), "On cooldown");
        require(msg.value >= refreshPrice, "Insufficient amount");     
        clearEffect(caster, EFFECT_COOLDOWN);
    }

    /**
        Effects
     */
    function getEffects(address caster) public view returns (IEffectData[] memory) {
        uint8 activeEffects = 0;
        for(uint8 i = 0; i < EFFECT_TOTAL; ++i) if (CASTER.hasEffect(caster, i)) activeEffects++;

        IEffectData[] memory effects = new IEffectData[](activeEffects);

        uint8 counter = 0;
        for(uint8 i = 0; i < EFFECT_TOTAL; ++i) {
            if (CASTER.hasEffect(caster, i)) {
                (uint256 timestamp, uint256 duration) = CASTER.getEffect(caster, i);
                effects[counter].effectId = i;
                effects[counter].countdown = (timestamp + duration) - block.timestamp;
                counter ++;
            }            
        }
        return effects;
    }

    function hasCooldown(address caster) public view returns (bool) {
        return CASTER.hasEffect(caster, EFFECT_COOLDOWN);
    }


    function isProtected(address target) public view returns (bool) {
        return CASTER.hasEffect(target, EFFECT_PROTECT) || CASTER.hasEffect(target, EFFECT_IMMUNE);
    }


    // This spell will froze an account balance for a certain time (unable to sell/transfer), can be cured by buying some token
    // Payed by token
    function castFreeze(address target) public onlySpellBook(_msgSender()) whenNotPaused notProtected(target) noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_FREEZE];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Freeze the target
        uint256 duration = setEffect(target, EFFECT_FREEZE, spell, book.level);

        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, target, SPELL_FREEZE, duration);
    }

    function castProtect() public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_PROTECT];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Protect the caster
        uint256 duration = setEffect(caster, EFFECT_PROTECT, spell, book.level);

        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, caster, SPELL_PROTECT, duration);
    }

    function castDispel(address target) public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_DISPEL];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Remove effects from target
        clearEffect(target, EFFECT_FREEZE);
        clearEffect(target, EFFECT_PROTECT);
        clearEffect(target, EFFECT_STOLEN);

        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, target, SPELL_DISPEL, 0);
    }
    
    function castMint() public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_MINT];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        uint256 percentage = getEffect(spell, book.level);
        curse.conjuration(caster, percentage);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, caster, SPELL_MINT, percentage);
    }

    function castBurn(address target) public onlySpellBook(_msgSender()) whenNotPaused notProtected(target) noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_BURN];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        uint256 percentage = getEffect(spell, book.level);
        curse.invocation(target, percentage);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, target, SPELL_BURN, percentage);
    }

    function castSteal(address target) public onlySpellBook(_msgSender()) whenNotPaused notProtected(target) noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_STEAL];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        uint256 percentage = getEffect(spell, book.level);
        curse.necromancy(target, caster, percentage);

        // Steal will give a unique effect to the caster for 1 hour
        CASTER.setEffect(caster, EFFECT_STOLEN, 1 hours);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, target, SPELL_STEAL, percentage);
    }
    
    function castInflate() public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_INFLATE];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        uint256 percentage = getEffect(spell, book.level);
        curse.alteration(percentage);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, address(0), SPELL_INFLATE, percentage);
    }

    function castDeflate() public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_DEFLATE];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        uint256 percentage = getEffect(spell, book.level);
        curse.divination(percentage);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, address(0), SPELL_DEFLATE, percentage);
    }

    function castDominate() public onlySpellBook(_msgSender()) whenNotPaused noCooldown(_msgSender()) {
        address caster = _msgSender();
        ICaster.SpellBookData memory book = CASTER.get(caster);
        ISpellConfig memory spell = spellConfig[SPELL_DOMINATE];

        // Calculate the price, and give discount based on level
        uint256 price = getPrice(spell, book.level);

        require(book.level >= spell.minLvlToCast, "Insufficient level");
        ensureCurseBalance(price, caster);

        // Cast the address to a specific instance interface
        address payable curseAddr = payable(address(CURSE));
        ICurse curse = ICurse(curseAddr);

        curse.illusion(caster);
        
        CASTER.setXp(caster, book.currentXp + spell.xpRewardPerCast);
        // Calculate the cooldown based on level
        setCooldown(caster, spell, book.level);

        emit SpellCasted(caster, caster, SPELL_DOMINATE, 0);
    }

    receive() external payable {}
}

// File: /contracts/Interfaces/ICurse.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.8.7;

interface ICurse {

    function invocation(address target, uint256 percentage) external;
    function conjuration(address target, uint256 percentage) external;
    function necromancy(address target, address caster, uint256 percentage) external; 
    function alteration(uint256 percentage) external; 
    function divination(uint256 percentage) external; 
    function illusion(address caster) external; 
    
}
// File: /contracts/Interfaces/ICaster.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.8.7;

interface ICaster {

    struct EffectData {
        uint256 timestamp;
        uint256 duration;
    }

    struct SpellBookData {
        uint256 currentXp;
        uint256 createdAt;
        uint8 level;
    }

    function hasEffect(address caster, uint8 effectId) external view returns (bool);
    function setEffect(address caster, uint8 effectId, uint256 duration) external;
    function clearEffect(address caster, uint8 effectId) external;
    function getEffect(address caster, uint8 effectId) external view returns (uint256, uint256);
    function setXp(address caster, uint256 xp) external; 
    function setLevel(address caster, uint8 level) external;
    function getLevel(address caster) external view returns(uint8);
    function get(address caster) external view returns (SpellBookData memory);
    function set(SpellBookData memory data, address caster) external;   
    function create(address caster) external;   
}
// 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: @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/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @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);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }
}

// 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/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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
                /// @solidity memory-safe-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/extensions/draft-IERC20Permit.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

    /**
     * @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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from,
        address to,
        uint256 amount
    ) external returns (bool);
}

// File: @openzeppelin/contracts/security/Pausable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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/access/IAccessControl.sol



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

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControl {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/AccessControl.sol)

pragma solidity ^0.8.0;

import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context, IAccessControl, ERC165 {
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

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

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        Strings.toHexString(uint160(account), 20),
                        " is missing role ",
                        Strings.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleGranted} event.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleRevoked} event.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * May emit a {RoleGranted} event.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}