// File: contracts/NFTStaking.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

/*
 ▄████▄   ██▀███   ▄▄▄      ▒███████▒▓██   ██▓
▒██▀ ▀█  ▓██ ▒ ██▒▒████▄    ▒ ▒ ▒ ▄▀░ ▒██  ██▒
▒▓█    ▄ ▓██ ░▄█ ▒▒██  ▀█▄  ░ ▒ ▄▀▒░   ▒██ ██░
▒▓▓▄ ▄██▒▒██▀▀█▄  ░██▄▄▄▄██   ▄▀▒   ░  ░ ▐██▓░
▒ ▓███▀ ░░██▓ ▒██▒ ▓█   ▓██▒▒███████▒  ░ ██▒▓░
░ ░▒ ▒  ░░ ▒▓ ░▒▓░ ▒▒   ▓▒█░░▒▒ ▓░▒░▒   ██▒▒▒
  ░  ▒     ░▒ ░ ▒░  ▒   ▒▒ ░░░▒ ▒ ░ ▒ ▓██ ░▒░
░          ░░   ░   ░   ▒   ░ ░ ░ ░ ░ ▒ ▒ ░░
░ ░         ░           ░  ░  ░ ░     ░ ░
░                           ░         ░ ░
 ▄████▄   ██▓     ▒█████   █     █░ ███▄    █   ██████
▒██▀ ▀█  ▓██▒    ▒██▒  ██▒▓█░ █ ░█░ ██ ▀█   █ ▒██    ▒
▒▓█    ▄ ▒██░    ▒██░  ██▒▒█░ █ ░█ ▓██  ▀█ ██▒░ ▓██▄
▒▓▓▄ ▄██▒▒██░    ▒██   ██░░█░ █ ░█ ▓██▒  ▐▌██▒  ▒   ██▒
▒ ▓███▀ ░░██████▒░ ████▓▒░░░██▒██▓ ▒██░   ▓██░▒██████▒▒
░ ░▒ ▒  ░░ ▒░▓  ░░ ▒░▒░▒░ ░ ▓░▒ ▒  ░ ▒░   ▒ ▒ ▒ ▒▓▒ ▒ ░
  ░  ▒   ░ ░ ▒  ░  ░ ▒ ▒░   ▒ ░ ░  ░ ░░   ░ ▒░░ ░▒  ░ ░
░          ░ ░   ░ ░ ░ ▒    ░   ░     ░   ░ ░ ░  ░  ░
░ ░          ░  ░    ░ ░      ░             ░       ░
░

Crazy Clowns Insane Asylum
2021, V1.1
https://ccia.io
*/

import '@openzeppelin/contracts/utils/math/SafeMath.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import './CrazyClown.sol';
import './BalloonToken.sol';
import './NFTExtension.sol';

/**
 * @title NFTStaking
 * @dev Stake NFTs, earn ballon tokens
 * @author
 */

contract NFTStaking is Ownable {
  using SafeMath for uint256;

  // ERC20 Reward Token
  BalloonToken public rewardsToken;

  struct Pool {
    uint256 lastRewardBlock;
    uint256 rewardsEarned;
    uint256 rewardsReleased;
  }

  struct Stake {
    mapping(uint256 => Pool) pool;
    uint256[] tokenIds;
    mapping(uint256 => uint256) tokenIndex;
  }

  struct StakeParam {
    address _contract;
    uint256 _tokenId;
  }

  struct Path {
    address to_address;
    bool burn_original;
    BalloonToken fee_contract;
    uint256 evolve_fee;
  }

  mapping(address => Path) public evolvePathList;
  mapping(address => bool) public evolvePathExists;

  // Registered NFT List
  mapping(address => NFTExtension) public NFTTokens;
  mapping(address => bool) _isNFTRegistered;
  address[] NFTTokenList;

  // Blocks per day
  uint256 public blockPerDay = 5760;

  // Mapping of a NFT contract to mapping from account to Stake struct
  mapping(address => mapping(address => Stake)) stakers;

  // Turn staking on/off
  bool public allowStaking;

  // Turn claim reward on/off
  bool public allowClaiming;

  // Mapping from a NFT Contract to a mapping from a token ID to owner address
  mapping(address => mapping(uint256 => address)) public tokenOwner;

  // Mapping from NFT address to its daily reward
  mapping(address => uint256) public dailyReward;

  // @notice event emitted when a user has staked a token
  event Staked(address owner, address tokenAddress, uint256 amount);

  // @notice event emitted when a user has unstaked a token
  event Unstaked(address owner, address tokenAddress, uint256 amount);

  // @notice event emitted when a user claims reward
  event RewardPaid(address indexed user, uint256 reward);

  /// @notice Emergency unstake tokens without rewards
  event EmergencyUnstake(address indexed user, uint256 tokenId);

  modifier isAllowedStaking() {
    require(allowStaking, 'Staking is currently disabled');
    _;
  }

  modifier isAllowedClaiming() {
    require(allowClaiming, 'Claiming is currently disabled');
    _;
  }

  constructor(BalloonToken _rewardsToken) {
    rewardsToken = _rewardsToken;
  }

  /// @notice Function allows us to add or update an external NFT contract address along with dailyReward
  function addNftReward(address contract_address, uint256 reward_per_block_day) public {
    require(!_isNFTRegistered[contract_address], 'Contract has been already registered');
    dailyReward[contract_address] = reward_per_block_day;
    NFTTokens[contract_address] = NFTExtension(contract_address);
    NFTTokenList.push(contract_address);
    _isNFTRegistered[contract_address] = true;
  }

  /// @notice function will allow us to remove an external NFT contract address.
  function removeNftReward(address contract_address) public {
    require(_isNFTRegistered[contract_address], 'Contract is not registered');
    delete dailyReward[contract_address];
    delete NFTTokens[contract_address];
    // Remove from registered NFT Contract List
    for (uint256 i = 0; i < NFTTokenList.length; i++) {
      if (NFTTokenList[i] == contract_address) {
        NFTTokenList[i] = NFTTokenList[NFTTokenList.length - 1];
        NFTTokenList.pop();
        break;
      }
    }
    _isNFTRegistered[contract_address] = false;
  }

  function _getNFTTokenList() external view returns (address[] memory) {
    return NFTTokenList;
  }

  function stakeBatch(StakeParam[] memory _tokenList) external isAllowedStaking {
    for (uint256 i = 0; i < _tokenList.length; i++) {
      _stake(msg.sender, _tokenList[i]._contract, _tokenList[i]._tokenId);
    }
  }

  /// @notice Stake NFTs and earn reward tokens.
  function stake(
    address _tokenAddress,
    uint256 _tokenId,
    address account
  ) external isAllowedStaking {
    require(_tokenAddress != address(0), 'Token Address is null');
    // require(NFTTokens[_tokenAddress].name(), "NFT Token is not registered");
    require(account == _msgSender() || _msgSender() == _tokenAddress, 'DONT GIVE YOUR TOKENS AWAY');
    if (_msgSender() != _tokenAddress) {
      require(NFTTokens[_tokenAddress].ownerOf(_tokenId) == msg.sender, 'msg.sender is not owner of token');
      _stake(msg.sender, _tokenAddress, _tokenId);
    } else {
      require(NFTTokens[_tokenAddress].ownerOf(_tokenId) == account, 'account is not owner of token');
      _stake(account, _tokenAddress, _tokenId);
    }
  }

  /**
   * @dev All the staking goes through this function
   */
  function _stake(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) internal {
    Stake storage _item = stakers[_tokenAddress][_user];
    _item.pool[_tokenId].lastRewardBlock = block.number;
    _item.tokenIds.push(_tokenId);
    _item.tokenIndex[_tokenId] = _item.tokenIds.length - 1;
    tokenOwner[_tokenAddress][_tokenId] = _user;

    NFTTokens[_tokenAddress].transferFrom(_user, address(this), _tokenId);

    emit Staked(_user, _tokenAddress, _tokenId);
  }

  function unstake(address _tokenAddress, uint256 _tokenId) external {
    require(_tokenAddress != address(0), 'Token Address is null');
    require(tokenOwner[_tokenAddress][_tokenId] == msg.sender, 'Sender must have staked tokenID');
    _claimReward(msg.sender, _tokenAddress, _tokenId);
    _unstake(msg.sender, _tokenAddress, _tokenId);
  }

  /**
   * @dev All the unstaking goes through this function
   * @dev Rewards to be given out is calculated
   */
  function _unstake(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) internal {
    Stake storage _item = stakers[_tokenAddress][_user];
    delete _item.pool[_tokenId];

    uint256 lastIndex = _item.tokenIds.length - 1;
    uint256 lastIndexKey = _item.tokenIds[lastIndex];
    uint256 tokenIdIndex = _item.tokenIndex[_tokenId];

    _item.tokenIds[tokenIdIndex] = lastIndexKey;
    _item.tokenIndex[lastIndexKey] = tokenIdIndex;
    if (_item.tokenIds.length > 0) {
      _item.tokenIds.pop();
      delete _item.tokenIndex[_tokenId];
    }

    delete tokenOwner[_tokenAddress][_tokenId];

    NFTTokens[_tokenAddress].transferFrom(address(this), _user, _tokenId);
    emit Unstaked(_user, _tokenAddress, _tokenId);
  }

  function pendingReward(address _tokenAddress, uint256 _tokenId) external view returns (uint256) {
    uint256 _reward = _pendingReward(msg.sender, _tokenAddress, _tokenId);
    return _reward;
  }

  // View function to see pending Reward on frontend.
  function _pendingReward(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) internal view returns (uint256) {
    Pool storage _pool = stakers[_tokenAddress][_user].pool[_tokenId];
    uint256 tokenReward = ((block.number).sub(_pool.lastRewardBlock)).mul(dailyReward[_tokenAddress]).div(blockPerDay);
    return tokenReward;
  }

  // Updates the reward earned per staked Token.
  function updateReward(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) internal {
    Pool storage _pool = stakers[_tokenAddress][_user].pool[_tokenId];
    uint256 _reward = _pendingReward(_user, _tokenAddress, _tokenId);
    _pool.rewardsEarned = _pool.rewardsEarned.add(_reward);
    _pool.lastRewardBlock = block.number;
  }

  function claimReward(address _tokenAddress, uint256 _tokenId) external {
    require(_tokenAddress != address(0), 'TokenAddress is null');
    _claimReward(msg.sender, _tokenAddress, _tokenId);
  }

  /// @notice Lets a user with rewards owing to claim tokens
  function _claimReward(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) internal isAllowedClaiming {
    updateReward(_user, _tokenAddress, _tokenId);
    Pool storage _pool = stakers[_tokenAddress][_user].pool[_tokenId];

    uint256 payableAmount = _pool.rewardsEarned.sub(_pool.rewardsReleased);
    _pool.rewardsReleased = _pool.rewardsReleased.add(payableAmount);

    rewardsToken.mint(_user, payableAmount);
    emit RewardPaid(_user, payableAmount);
  }

  /// @dev Getter functions for NFTStaking contract
  /// @dev Get the tokens staked by a user
  function getStakedTokens(address _user, address _tokenAddress) external view returns (uint256[] memory tokenIds) {
    return stakers[_tokenAddress][_user].tokenIds;
  }

  // Unstake without caring about rewards. EMERGENCY ONLY.
  function emergencyUnstake(address _tokenAddress, uint256 _tokenId) public {
    require(tokenOwner[_tokenAddress][_tokenId] == msg.sender, 'Sender must have staked tokenID');
    _unstake(msg.sender, _tokenAddress, _tokenId);
    emit EmergencyUnstake(msg.sender, _tokenId);
  }

  // Claim all the staked tokens from registered NFT contracts
  function claimAll() public {
    for (uint256 i = 0; i < NFTTokenList.length; i++) {
      address _tokenAddress = NFTTokenList[i];
      uint256[] storage tokenList = stakers[_tokenAddress][msg.sender].tokenIds;
      for (uint256 index = 0; index < tokenList.length; index++) {
        _claimReward(msg.sender, _tokenAddress, tokenList[index]);
      }
    }
  }

  // Public function to Update blockPerDay
  function updateBlockPerDay(uint256 _blockPerDay) public {
    blockPerDay = _blockPerDay;
  }

  // Function to register evolve path
  function addEvolvePath(
    address from_address,
    address to_address,
    bool burn_original,
    address fee_contract,
    uint256 evolve_fee
  ) external onlyOwner {
    require(from_address != address(0), 'Contract From Address is null');
    require(to_address != address(0), 'Contract to Address is null');
    require(fee_contract != address(0), 'Fee Contract  to Address is null');

    evolvePathList[from_address].to_address = to_address;
    evolvePathList[from_address].burn_original = burn_original;
    evolvePathList[from_address].fee_contract = BalloonToken(fee_contract);
    evolvePathList[from_address].evolve_fee = evolve_fee;
    evolvePathExists[from_address] = true;
  }

  // Function to delete evolve Path
  function deleteEvolvePath(address from_address) external onlyOwner {
    require(from_address != address(0), 'Contract From Address is null');
    delete evolvePathList[from_address];
    evolvePathExists[from_address] = false;
  }

  // Function to evolve NFT
  function evolvePath(
    address original_nft_address,
    uint256 token_id,
    bool isStaked
  ) external {
    require(original_nft_address != address(0), 'Original NFT Contract address is null');
    Path storage _path = evolvePathList[original_nft_address];
    if (isStaked) {
      // Evolve from Staked
      _unstake(msg.sender, original_nft_address, token_id);
    } else {
      // check to see if user has token_id in the original nft address
      require(NFTTokens[original_nft_address].ownerOf(token_id) == msg.sender, 'msg.sender is not owner of token');
    }

    // check to see if evolve path is registered
    require(evolvePathExists[original_nft_address], 'Evolve Path from original nft address is not registered');

    BalloonToken feeContract = _path.fee_contract;
    uint256 balanceOfSender = feeContract.balanceOf(address(msg.sender));
    // check to see if user has token amount to evolve
    require(balanceOfSender > _path.evolve_fee, 'User does not have enough ballon to evolve');

    // burn original token if burn_original of corresponding evolve path is true
    if (_path.burn_original) {
      NFTTokens[original_nft_address].burn(token_id);
    }
    // Transfer Balloon Fee Token to evolveToAddress Contract
    feeContract.burn(msg.sender, _path.evolve_fee);
    // Mint a new NFT Token to msg.sender
    uint256 _evolvedTokenId = NFTTokens[_path.to_address].evolve_mint(msg.sender);
    // Stake Evolved NFT if original token was staked.
    if (isStaked) {
      _stake(msg.sender, _path.to_address, _evolvedTokenId);
    }
  }

  function toggleAllowStaking() external onlyOwner {
    allowStaking = !allowStaking;
  }

  function toggleAllowClaiming() external onlyOwner {
    allowClaiming = !allowClaiming;
  }
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



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

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

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



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

// File: contracts/CrazyClown.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

/*
 ▄████▄   ██▀███   ▄▄▄      ▒███████▒▓██   ██▓
▒██▀ ▀█  ▓██ ▒ ██▒▒████▄    ▒ ▒ ▒ ▄▀░ ▒██  ██▒
▒▓█    ▄ ▓██ ░▄█ ▒▒██  ▀█▄  ░ ▒ ▄▀▒░   ▒██ ██░
▒▓▓▄ ▄██▒▒██▀▀█▄  ░██▄▄▄▄██   ▄▀▒   ░  ░ ▐██▓░
▒ ▓███▀ ░░██▓ ▒██▒ ▓█   ▓██▒▒███████▒  ░ ██▒▓░
░ ░▒ ▒  ░░ ▒▓ ░▒▓░ ▒▒   ▓▒█░░▒▒ ▓░▒░▒   ██▒▒▒
  ░  ▒     ░▒ ░ ▒░  ▒   ▒▒ ░░░▒ ▒ ░ ▒ ▓██ ░▒░
░          ░░   ░   ░   ▒   ░ ░ ░ ░ ░ ▒ ▒ ░░
░ ░         ░           ░  ░  ░ ░     ░ ░
░                           ░         ░ ░
 ▄████▄   ██▓     ▒█████   █     █░ ███▄    █   ██████
▒██▀ ▀█  ▓██▒    ▒██▒  ██▒▓█░ █ ░█░ ██ ▀█   █ ▒██    ▒
▒▓█    ▄ ▒██░    ▒██░  ██▒▒█░ █ ░█ ▓██  ▀█ ██▒░ ▓██▄
▒▓▓▄ ▄██▒▒██░    ▒██   ██░░█░ █ ░█ ▓██▒  ▐▌██▒  ▒   ██▒
▒ ▓███▀ ░░██████▒░ ████▓▒░░░██▒██▓ ▒██░   ▓██░▒██████▒▒
░ ░▒ ▒  ░░ ▒░▓  ░░ ▒░▒░▒░ ░ ▓░▒ ▒  ░ ▒░   ▒ ▒ ▒ ▒▓▒ ▒ ░
  ░  ▒   ░ ░ ▒  ░  ░ ▒ ▒░   ▒ ░ ░  ░ ░░   ░ ▒░░ ░▒  ░ ░
░          ░ ░   ░ ░ ░ ▒    ░   ░     ░   ░ ░ ░  ░  ░
░ ░          ░  ░    ░ ░      ░             ░       ░
░

Crazy Clowns Insane Asylum
2021, V1.1
https://ccia.io
*/

import '@openzeppelin/contracts/utils/Counters.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import './NFTExtension.sol';
import './Metadata.sol';
import './interfaces/INFTStaking.sol';

contract CrazyClown is Metadata, NFTExtension {
  using Counters for Counters.Counter;
  using Strings for uint256;

  // Counter service to determine tokenId
  Counters.Counter private _tokenIds;

  // General details
  uint256 public constant maxSupply = 9696;

  // Public sale details
  uint256 public price = 0.05 ether; // Public sale price
  uint256 public publicSaleTransLimit = 10; // Public sale limit per transaction
  uint256 public publicMintLimit = 500; // Public mint limit per Wallet
  bool private _publicSaleStarted; // Flag to enable public sale
  mapping(address => uint256) public mintListPurchases;

  // Presale sale details
  uint256 public preSalePrice = 0.04 ether;
  uint256 public preSaleMintLimit = 10; // Presale limit per wallet
  bool public preSaleLive = false;
  Counters.Counter private preSaleAmountMinted;
  mapping(address => uint256) public preSaleListPurchases;
  mapping(address => bool) public preSaleWhitelist;

  // Reserve details for founders / gifts
  uint256 private reservedSupply = 196;

  // Metadata details
  string _baseTokenURI;
  string _contractURI;

  //NFTStaking interface
  INFTStaking public nftStaking;

  // Whitelist contracts
  address[] contractWhitelist;
  mapping(address => uint256) contractWhitelistIndex;

  constructor(
    string memory name,
    string memory symbol,
    string memory baseURI,
    string memory contractStoreURI,
    address utilityToken,
    address _proxyRegistryAddress
  ) ERC721(name, symbol) Metadata(utilityToken, maxSupply) {
    _publicSaleStarted = false;
    _baseTokenURI = baseURI;
    _contractURI = contractStoreURI;
    admins[_msgSender()] = true;
    proxyRegistryAddress = _proxyRegistryAddress;
  }

  // Public sale functions
  modifier whenPublicSaleStarted() {
    require(_publicSaleStarted, 'Sale has not yet started');
    _;
  }

  function flipPublicSaleStarted() external onlyOwner {
    _publicSaleStarted = !_publicSaleStarted;
  }

  function saleStarted() public view returns (bool) {
    return _publicSaleStarted;
  }

  function mint(uint256 _nbTokens, bool allowStaking) external payable override {
    // Presale minting
    require(_publicSaleStarted || preSaleLive, 'Sale has not yet started');
    uint256 _currentSupply = _tokenIds.current();
    if (!_publicSaleStarted && preSaleLive) {
      require(preSaleWhitelist[msg.sender] || isWhitelistContractHolder(msg.sender), 'Not on presale whitelist');
      require(preSaleListPurchases[msg.sender] + _nbTokens <= preSaleMintLimit, 'Exceeded presale allowed buy limit');
      require(preSalePrice * _nbTokens <= msg.value, 'Insufficient ETH');
      for (uint256 i = 0; i < _nbTokens; i++) {
        preSaleAmountMinted.increment();
        _tokenIds.increment();
        uint256 newItemId = _tokenIds.current();
        preSaleListPurchases[msg.sender]++;
        tokenMintDate[newItemId] = block.timestamp;
        _safeMint(msg.sender, newItemId);
        if (allowStaking) {
          nftStaking.stake(address(this), newItemId, msg.sender);
        }
      }
    } else if (_publicSaleStarted) {
      // Public sale minting
      require(_nbTokens <= publicSaleTransLimit, 'You cannot mint that many NFTs at once');
      require(_currentSupply + _nbTokens <= maxSupply - reservedSupply, 'Not enough Tokens left.');
      require(mintListPurchases[msg.sender] + _nbTokens <= publicMintLimit, 'Exceeded sale allowed buy limit');
      require(_nbTokens * price <= msg.value, 'Insufficient ETH');
      for (uint256 i; i < _nbTokens; i++) {
        _tokenIds.increment();
        uint256 newItemId = _tokenIds.current();
        mintListPurchases[msg.sender]++;
        tokenMintDate[newItemId] = block.timestamp;
        _safeMint(msg.sender, newItemId);
        if (allowStaking) {
          setApprovalForAll(address(nftStaking), true);
          nftStaking.stake(address(this), newItemId, msg.sender);
        }
      }
    }
  }

  /**
   * called after deployment so that the contract can get NFT staking contracts
   * @param _nftStaking the address of the NFTStaking
   */
  function setNFTStaking(address _nftStaking) external onlyOwner {
    nftStaking = INFTStaking(_nftStaking);
  }

  function setPublicMintLimit(uint256 limit) external onlyOwner {
    publicMintLimit = limit;
  }

  function setPublicSaleTransLimit(uint256 limit) external onlyOwner {
    publicSaleTransLimit = limit;
  }

  // Make it possible to change the price: just in case
  function setPrice(uint256 _newPrice) external onlyOwner {
    price = _newPrice;
  }

  function getPrice() public view returns (uint256) {
    return price;
  }

  // Pre sale functions
  modifier whenPreSaleLive() {
    require(preSaleLive, 'Presale has not yet started');
    _;
  }

  modifier whenPreSaleNotLive() {
    require(!preSaleLive, 'Presale has already started');
    _;
  }

  function setPreSalePrice(uint256 _newPreSalePrice) external onlyOwner whenPreSaleNotLive {
    preSalePrice = _newPreSalePrice;
  }

  // Add an array of wallet addresses to the presale white list
  function addToPreSaleList(address[] calldata entries) external onlyOwner {
    for (uint256 i = 0; i < entries.length; i++) {
      address entry = entries[i];
      require(entry != address(0), 'NULL_ADDRESS');
      require(!preSaleWhitelist[entry], 'DUPLICATE_ENTRY');

      preSaleWhitelist[entry] = true;
    }
  }

  // Remove an array of wallet addresses to the presale white list
  function removeFromPreSaleList(address[] calldata entries) external onlyOwner {
    for (uint256 i = 0; i < entries.length; i++) {
      address entry = entries[i];
      require(entry != address(0), 'NULL_ADDRESS');
      preSaleWhitelist[entry] = false;
    }
  }

  function isPreSaleApproved(address addr) external view returns (bool) {
    return preSaleWhitelist[addr];
  }

  function flipPreSaleStatus() external onlyOwner {
    preSaleLive = !preSaleLive;
  }

  function getPreSalePrice() public view returns (uint256) {
    return preSalePrice;
  }

  function setPreSaleMintLimit(uint256 _newPresaleMintLimit) external onlyOwner {
    preSaleMintLimit = _newPresaleMintLimit;
  }

  // Reserve functions
  // Owner to send reserve NFT to address
  function sendReserve(address _receiver, uint256 _nbTokens) public onlyAdmin {
    uint256 _currentSupply = _tokenIds.current();
    require(_currentSupply + _nbTokens <= maxSupply - reservedSupply, 'Not enough supply left');
    require(_nbTokens <= reservedSupply, 'That would exceed the max reserved');
    for (uint256 i; i < _nbTokens; i++) {
      _tokenIds.increment();
      uint256 newItemId = _tokenIds.current();
      tokenMintDate[newItemId] = block.timestamp;
      _safeMint(_receiver, newItemId);
    }
    reservedSupply = reservedSupply - _nbTokens;
  }

  function getReservedLeft() public view whenPublicSaleStarted returns (uint256) {
    return reservedSupply;
  }

  // Make it possible to change the reserve only if sale not started: just in case
  function setReservedSupply(uint256 _newReservedSupply) external onlyOwner {
    reservedSupply = _newReservedSupply;
  }

  // Storefront metadata
  // https://docs.opensea.io/docs/contract-level-metadata
  function contractURI() public view returns (string memory) {
    return _contractURI;
  }

  function setContractURI(string memory _URI) external onlyOwner {
    _contractURI = _URI;
  }

  function setBaseURI(string memory _URI) external onlyOwner {
    _baseTokenURI = _URI;
  }

  function _baseURI() internal view override(ERC721) returns (string memory) {
    return _baseTokenURI;
  }

  // General functions & helper functions
  // Helper to list all the NFTs of a wallet
  function walletOfOwner(address _owner) public view returns (uint256[] memory) {
    uint256 tokenCount = balanceOf(_owner);
    uint256[] memory tokensId = new uint256[](tokenCount);
    for (uint256 i; i < tokenCount; i++) {
      tokensId[i] = tokenOfOwnerByIndex(_owner, i);
    }
    return tokensId;
  }

  function withdraw(address _receiver) public onlyOwner {
    uint256 _balance = address(this).balance;

    require(payable(_receiver).send(_balance));
  }

  function burn(uint256 tokenId) external override onlyAdmin {
    _burn(tokenId);
  }

  /**
   * @dev See {IERC721-transferFrom}.
   */
  function transferFrom(
    address from,
    address to,
    uint256 tokenId
  ) public virtual override {
    _transfer(from, to, tokenId);
  }

  function addContractToWhitelist(address _contract) external onlyOwner {
    contractWhitelist.push(_contract);
    contractWhitelistIndex[_contract] = contractWhitelist.length - 1;
  }

  function removeContractFromWhitelist(address _contract) external onlyOwner {
    uint256 lastIndex = contractWhitelist.length - 1;
    address lastContract = contractWhitelist[lastIndex];
    uint256 contractIndex = contractWhitelistIndex[_contract];

    contractWhitelist[contractIndex] = lastContract;
    contractWhitelistIndex[lastContract] = contractIndex;
    if (contractWhitelist.length > 0) {
      contractWhitelist.pop();
      delete contractWhitelistIndex[_contract];
    }
  }

  function isWhitelistContractHolder(address user) internal view returns (bool) {
    for (uint256 index = 0; index < contractWhitelist.length; index++) {
      uint256 balanceOfSender = IERC721(contractWhitelist[index]).balanceOf(user);
      if (balanceOfSender > 0) return true;
    }
    return false;
  }

  function tokenURI(uint256 tokenId) public view override returns (string memory) {
    require(tokenId <= _tokenIds.current(), 'Token does not exist');
    if (PublicRevealStatus) return super.tokenURI(tokenId);
    else return placeHolderURI;
  }

  function isWhitelisted() public view returns (bool) {
    return (preSaleWhitelist[msg.sender] || isWhitelistContractHolder(msg.sender));
  }
}

// File: contracts/BalloonToken.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

/*
 ▄████▄   ██▀███   ▄▄▄      ▒███████▒▓██   ██▓
▒██▀ ▀█  ▓██ ▒ ██▒▒████▄    ▒ ▒ ▒ ▄▀░ ▒██  ██▒
▒▓█    ▄ ▓██ ░▄█ ▒▒██  ▀█▄  ░ ▒ ▄▀▒░   ▒██ ██░
▒▓▓▄ ▄██▒▒██▀▀█▄  ░██▄▄▄▄██   ▄▀▒   ░  ░ ▐██▓░
▒ ▓███▀ ░░██▓ ▒██▒ ▓█   ▓██▒▒███████▒  ░ ██▒▓░
░ ░▒ ▒  ░░ ▒▓ ░▒▓░ ▒▒   ▓▒█░░▒▒ ▓░▒░▒   ██▒▒▒
  ░  ▒     ░▒ ░ ▒░  ▒   ▒▒ ░░░▒ ▒ ░ ▒ ▓██ ░▒░
░          ░░   ░   ░   ▒   ░ ░ ░ ░ ░ ▒ ▒ ░░
░ ░         ░           ░  ░  ░ ░     ░ ░
░                           ░         ░ ░
 ▄████▄   ██▓     ▒█████   █     █░ ███▄    █   ██████
▒██▀ ▀█  ▓██▒    ▒██▒  ██▒▓█░ █ ░█░ ██ ▀█   █ ▒██    ▒
▒▓█    ▄ ▒██░    ▒██░  ██▒▒█░ █ ░█ ▓██  ▀█ ██▒░ ▓██▄
▒▓▓▄ ▄██▒▒██░    ▒██   ██░░█░ █ ░█ ▓██▒  ▐▌██▒  ▒   ██▒
▒ ▓███▀ ░░██████▒░ ████▓▒░░░██▒██▓ ▒██░   ▓██░▒██████▒▒
░ ░▒ ▒  ░░ ▒░▓  ░░ ▒░▒░▒░ ░ ▓░▒ ▒  ░ ▒░   ▒ ▒ ▒ ▒▓▒ ▒ ░
  ░  ▒   ░ ░ ▒  ░  ░ ▒ ▒░   ▒ ░ ░  ░ ░░   ░ ▒░░ ░▒  ░ ░
░          ░ ░   ░ ░ ░ ▒    ░   ░     ░   ░ ░ ░  ░  ░
░ ░          ░  ░    ░ ░      ░             ░       ░
░

Crazy Clowns Insane Asylum
2021, V1.1
https://ccia.io
*/

import '@openzeppelin/contracts/token/ERC20/ERC20.sol';
import '@openzeppelin/contracts/access/Ownable.sol';

contract BalloonToken is ERC20, Ownable {
  mapping(address => bool) private minters;

  modifier onlyMinter() {
    require(minters[_msgSender()], 'Caller is not the minter');
    _;
  }

  constructor(uint256 initialSupply) ERC20('Balloon Token', 'BALLOON') {
    _mint(msg.sender, initialSupply * 10**decimals());
  }

  function _mint(address to, uint256 amount) internal override(ERC20) {
    super._mint(to, amount);
  }

  function mint(address to, uint256 amount) external onlyMinter {
    _mint(to, amount);
  }

  function _burn(address account, uint256 amount) internal override(ERC20) {
    super._burn(account, amount);
  }

  function burn(address account, uint256 amount) external {
    _burn(account, amount);
  }

  // Function to grant mint role
  function addMinterRole(address _address) external onlyOwner {
    minters[_address] = true;
  }

  // Function to revoke mint role
  function revokeMinterRole(address _address) external onlyOwner {
    minters[_address] = false;
  }
}

// File: contracts/NFTExtension.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

import '@openzeppelin/contracts/token/ERC721/ERC721.sol';
import '@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol';
import '@openzeppelin/contracts/utils/Counters.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/access/Ownable.sol';

/**
  @title An OpenSea delegate proxy contract which we include for whitelisting.
  @author OpenSea
*/
contract OwnableDelegateProxy {

}

/**
  @title An OpenSea proxy registry contract which we include for whitelisting.
  @author OpenSea
*/
contract ProxyRegistry {
  mapping(address => OwnableDelegateProxy) public proxies;
}

abstract contract NFTExtension is ERC721URIStorage, Ownable {
  using Counters for Counters.Counter;

  mapping(address => bool) internal admins;

  Counters.Counter internal _totalSupply;

  // Mapping from owner to list of owned token IDs
  mapping(address => mapping(uint256 => uint256)) private _ownedTokens;

  // Mapping from token ID to index of the owner tokens list
  mapping(uint256 => uint256) private _ownedTokensIndex;

  // Specifically whitelist an OpenSea proxy registry address.
  address public proxyRegistryAddress;

  modifier onlyAdmin() {
    require(admins[_msgSender()], 'Caller is not the admin');
    _;
  }

  /**
    An override to whitelist the OpenSea proxy contract to enable gas-free
    listings. This function returns true if `_operator` is approved to transfer
    items owned by `_owner`.
    @param _owner The owner of items to check for transfer ability.
    @param _operator The potential transferrer of `_owner`'s items.
  */
  function isApprovedForAll(address _owner, address _operator) public view override returns (bool isOperator) {
    ProxyRegistry proxyRegistry = ProxyRegistry(proxyRegistryAddress);
    if (address(proxyRegistry.proxies(_owner)) == _operator) {
      return true;
    }
    return super.isApprovedForAll(_owner, _operator);
  }

  // Function to grant admin role
  function addAdminRole(address _address) external onlyOwner {
    admins[_address] = true;
  }

  // Function to revoke admin role
  function revokeAdminRole(address _address) external onlyOwner {
    admins[_address] = false;
  }

  function hasAdminRole(address _address) external view returns (bool) {
    return admins[_address];
  }

  function _burn(uint256 tokenId) internal override(ERC721URIStorage) {
    super._burn(tokenId);
  }

  // Support Interface
  /*  function supportsInterface(bytes4 interfaceId) public view virtual override(ERC721) returns (bool) {
    return super.supportsInterface(interfaceId);
  } */

  function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual returns (uint256) {
    require(index < balanceOf(owner), 'ERC721Enumerable: owner index out of bounds');
    return _ownedTokens[owner][index];
  }

  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 tokenId
  ) internal override {
    super._beforeTokenTransfer(from, to, tokenId);

    if (from == address(0)) {
      _totalSupply.increment();
    } else if (from != to) {
      _removeTokenFromOwnerEnumeration(from, tokenId);
    }

    if (to == address(0)) {
      _totalSupply.decrement();
    } else if (to != from) {
      _addTokenToOwnerEnumeration(to, tokenId);
    }
  }

  function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
    uint256 length = balanceOf(to);
    _ownedTokens[to][length] = tokenId;
    _ownedTokensIndex[tokenId] = length;
  }

  function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
    // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
    // then delete the last slot (swap and pop).

    uint256 lastTokenIndex = balanceOf(from) - 1;
    uint256 tokenIndex = _ownedTokensIndex[tokenId];

    // When the token to delete is the last token, the swap operation is unnecessary
    if (tokenIndex != lastTokenIndex) {
      uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

      _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
      _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
    }

    // This also deletes the contents at the last position of the array
    delete _ownedTokensIndex[tokenId];
    delete _ownedTokens[from][lastTokenIndex];
  }

  function totalSupply() public view returns (uint256) {
    return _totalSupply.current();
  }

  // function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {}

  function burn(uint256 tokenId) external virtual {}

  function mint(uint256 _nbTokens, bool nftStaking) external payable virtual {}

  function evolve_mint(address _user) external virtual returns (uint256) {}
}

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



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

pragma solidity ^0.8.0;

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

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

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



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

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

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



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

pragma solidity ^0.8.0;

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

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

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

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

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

// File: contracts/Metadata.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

pragma experimental ABIEncoderV2;
import { Base64 } from 'base64-sol/base64.sol';
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/utils/Strings.sol';
import '@openzeppelin/contracts/access/Ownable.sol';
import './interfaces/IBalloonToken.sol';

contract Metadata is Ownable {
  using Strings for uint256;

  // utility token
  IBalloonToken public utilityToken;

  // Utility Token Fee to update Name, Bio
  uint256 public _changeNameFee = 10 * 10**18;
  uint256 public _changeBioFee = 25 * 10**18;
  uint256 TotalSupply;

  // Image Placeholder URI
  string public placeHolderURI;

  // Public Reveal Status
  bool public PublicRevealStatus = false;

  struct Meta {
    string name;
    string description;
  }

  // Mapping from tokenId to meta struct
  mapping(uint256 => Meta) metaList;

  // Mapping from tokenId to boolean to make sure name is updated.
  mapping(uint256 => bool) _isNameUpdated;

  // Mapping from tokenId to boolean to make sure bio is updated.
  mapping(uint256 => bool) _isBioUpdated;

  // Mapping from token Id to mint date
  mapping(uint256 => uint256) tokenMintDate;

  constructor(address _utilityToken, uint256 _totalSupply) {
    utilityToken = IBalloonToken(_utilityToken);
    TotalSupply = _totalSupply;
  }

  function changeName(uint256 _tokenId, string memory _name) external {
    Meta storage _meta = metaList[_tokenId];
    _meta.name = _name;
    _isNameUpdated[_tokenId] = true;
    utilityToken.burn(msg.sender, _changeNameFee);
  }

  function changeBio(uint256 _tokenId, string memory _bio) external {
    Meta storage _meta = metaList[_tokenId];
    _meta.description = _bio;
    _isBioUpdated[_tokenId] = true;
    utilityToken.burn(msg.sender, _changeBioFee);
  }

  function getTokenName(uint256 _tokenId) public view returns (string memory) {
    return metaList[_tokenId].name;
  }

  function getTokenBio(uint256 _tokenId) public view returns (string memory) {
    return metaList[_tokenId].description;
  }

  function setPlaceholderURI(string memory uri) public onlyOwner {
    placeHolderURI = uri;
  }

  function togglePublicReveal() external onlyOwner {
    PublicRevealStatus = !PublicRevealStatus;
  }

  function _getTokenMintDate(uint256 tokenId) internal view returns (uint256) {
    return tokenMintDate[tokenId];
  }

  function setChangeNameFee(uint256 _fee) external onlyOwner {
    _changeNameFee = _fee;
  }

  function setChangeBioFee(uint256 _fee) external onlyOwner {
    _changeBioFee = _fee;
  }
}

// File: contracts/interfaces/INFTStaking.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

/*
 ▄████▄   ██▀███   ▄▄▄      ▒███████▒▓██   ██▓
▒██▀ ▀█  ▓██ ▒ ██▒▒████▄    ▒ ▒ ▒ ▄▀░ ▒██  ██▒
▒▓█    ▄ ▓██ ░▄█ ▒▒██  ▀█▄  ░ ▒ ▄▀▒░   ▒██ ██░
▒▓▓▄ ▄██▒▒██▀▀█▄  ░██▄▄▄▄██   ▄▀▒   ░  ░ ▐██▓░
▒ ▓███▀ ░░██▓ ▒██▒ ▓█   ▓██▒▒███████▒  ░ ██▒▓░
░ ░▒ ▒  ░░ ▒▓ ░▒▓░ ▒▒   ▓▒█░░▒▒ ▓░▒░▒   ██▒▒▒
  ░  ▒     ░▒ ░ ▒░  ▒   ▒▒ ░░░▒ ▒ ░ ▒ ▓██ ░▒░
░          ░░   ░   ░   ▒   ░ ░ ░ ░ ░ ▒ ▒ ░░
░ ░         ░           ░  ░  ░ ░     ░ ░
░                           ░         ░ ░
 ▄████▄   ██▓     ▒█████   █     █░ ███▄    █   ██████
▒██▀ ▀█  ▓██▒    ▒██▒  ██▒▓█░ █ ░█░ ██ ▀█   █ ▒██    ▒
▒▓█    ▄ ▒██░    ▒██░  ██▒▒█░ █ ░█ ▓██  ▀█ ██▒░ ▓██▄
▒▓▓▄ ▄██▒▒██░    ▒██   ██░░█░ █ ░█ ▓██▒  ▐▌██▒  ▒   ██▒
▒ ▓███▀ ░░██████▒░ ████▓▒░░░██▒██▓ ▒██░   ▓██░▒██████▒▒
░ ░▒ ▒  ░░ ▒░▓  ░░ ▒░▒░▒░ ░ ▓░▒ ▒  ░ ▒░   ▒ ▒ ▒ ▒▓▒ ▒ ░
  ░  ▒   ░ ░ ▒  ░  ░ ▒ ▒░   ▒ ░ ░  ░ ░░   ░ ▒░░ ░▒  ░ ░
░          ░ ░   ░ ░ ░ ▒    ░   ░     ░   ░ ░ ░  ░  ░
░ ░          ░  ░    ░ ░      ░             ░       ░
░

Crazy Clowns Insane Asylum
2021, V1.1
https://ccia.io
*/

interface INFTStaking {
  function DEFAULT_ADMIN_ROLE() external view returns (bytes32);

  function NFTTokens(address) external view returns (address);

  function addEvolvePath(
    address from_address,
    address to_address,
    bool burn_original,
    address fee_contract,
    uint256 evolve_fee
  ) external;

  function addNftReward(address contract_address, uint256 reward_per_block_day) external;

  function blockPerDay() external view returns (uint256);

  function claimAll(address _tokenAddress) external;

  function claimReward(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) external;

  function dailyReward(address) external view returns (uint256);

  function deleteEvolvePath(address from_address) external;

  function emergencyUnstake(address _tokenAddress, uint256 _tokenId) external;

  function evolvePath(address original_nft_address, uint256 token_id) external;

  function evolvePathList(address)
    external
    view
    returns (
      address to_address,
      bool burn_original,
      address fee_contract,
      uint256 evolve_fee
    );

  function getRoleAdmin(bytes32 role) external view returns (bytes32);

  function getStakedTokens(address _user, address _tokenAddress) external view returns (uint256[] memory tokenIds);

  function grantRole(bytes32 role, address account) external;

  function hasRole(bytes32 role, address account) external view returns (bool);

  function pendingReward(
    address _user,
    address _tokenAddress,
    uint256 _tokenId
  ) external view returns (uint256);

  function removeNftReward(address contract_address) external;

  function renounceRole(bytes32 role, address account) external;

  function revokeRole(bytes32 role, address account) external;

  function rewardsToken() external view returns (address);

  function stake(
    address _tokenAddress,
    uint256 _tokenId,
    address _account
  ) external;

  function supportsInterface(bytes4 interfaceId) external view returns (bool);

  function tokenOwner(address, uint256) external view returns (address);

  function unstake(address _tokenAddress, uint256 _tokenId) external;

  function updateBlockPerDay(uint256 _blockPerDay) external;
}

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



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

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

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

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

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

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

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

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

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

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

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

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721URIStorage.sol)

pragma solidity ^0.8.0;

import "../ERC721.sol";

/**
 * @dev ERC721 token with storage based token URI management.
 */
abstract contract ERC721URIStorage is ERC721 {
    using Strings for uint256;

    // Optional mapping for token URIs
    mapping(uint256 => string) private _tokenURIs;

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721URIStorage: URI query for nonexistent token");

        string memory _tokenURI = _tokenURIs[tokenId];
        string memory base = _baseURI();

        // If there is no base URI, return the token URI.
        if (bytes(base).length == 0) {
            return _tokenURI;
        }
        // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
        if (bytes(_tokenURI).length > 0) {
            return string(abi.encodePacked(base, _tokenURI));
        }

        return super.tokenURI(tokenId);
    }

    /**
     * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
        require(_exists(tokenId), "ERC721URIStorage: URI set of nonexistent token");
        _tokenURIs[tokenId] = _tokenURI;
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual override {
        super._burn(tokenId);

        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

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

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

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

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

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

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

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

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



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

pragma solidity ^0.8.0;

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

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



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

pragma solidity ^0.8.0;

import "../IERC721.sol";

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

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

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

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



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

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/utils/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/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: base64-sol/base64.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0;

/// @title Base64
/// @author Brecht Devos - <brecht@loopring.org>
/// @notice Provides functions for encoding/decoding base64
library Base64 {
    string internal constant TABLE_ENCODE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    bytes  internal constant TABLE_DECODE = hex"0000000000000000000000000000000000000000000000000000000000000000"
                                            hex"00000000000000000000003e0000003f3435363738393a3b3c3d000000000000"
                                            hex"00000102030405060708090a0b0c0d0e0f101112131415161718190000000000"
                                            hex"001a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132330000000000";

    function encode(bytes memory data) internal pure returns (string memory) {
        if (data.length == 0) return '';

        // load the table into memory
        string memory table = TABLE_ENCODE;

        // multiply by 4/3 rounded up
        uint256 encodedLen = 4 * ((data.length + 2) / 3);

        // add some extra buffer at the end required for the writing
        string memory result = new string(encodedLen + 32);

        assembly {
            // set the actual output length
            mstore(result, encodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

            // result ptr, jump over length
            let resultPtr := add(result, 32)

            // run over the input, 3 bytes at a time
            for {} lt(dataPtr, endPtr) {}
            {
                // read 3 bytes
                dataPtr := add(dataPtr, 3)
                let input := mload(dataPtr)

                // write 4 characters
                mstore8(resultPtr, mload(add(tablePtr, and(shr(18, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr(12, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(shr( 6, input), 0x3F))))
                resultPtr := add(resultPtr, 1)
                mstore8(resultPtr, mload(add(tablePtr, and(        input,  0x3F))))
                resultPtr := add(resultPtr, 1)
            }

            // padding with '='
            switch mod(mload(data), 3)
            case 1 { mstore(sub(resultPtr, 2), shl(240, 0x3d3d)) }
            case 2 { mstore(sub(resultPtr, 1), shl(248, 0x3d)) }
        }

        return result;
    }

    function decode(string memory _data) internal pure returns (bytes memory) {
        bytes memory data = bytes(_data);

        if (data.length == 0) return new bytes(0);
        require(data.length % 4 == 0, "invalid base64 decoder input");

        // load the table into memory
        bytes memory table = TABLE_DECODE;

        // every 4 characters represent 3 bytes
        uint256 decodedLen = (data.length / 4) * 3;

        // add some extra buffer at the end required for the writing
        bytes memory result = new bytes(decodedLen + 32);

        assembly {
            // padding with '='
            let lastBytes := mload(add(data, mload(data)))
            if eq(and(lastBytes, 0xFF), 0x3d) {
                decodedLen := sub(decodedLen, 1)
                if eq(and(lastBytes, 0xFFFF), 0x3d3d) {
                    decodedLen := sub(decodedLen, 1)
                }
            }

            // set the actual output length
            mstore(result, decodedLen)

            // prepare the lookup table
            let tablePtr := add(table, 1)

            // input ptr
            let dataPtr := data
            let endPtr := add(dataPtr, mload(data))

            // result ptr, jump over length
            let resultPtr := add(result, 32)

            // run over the input, 4 characters at a time
            for {} lt(dataPtr, endPtr) {}
            {
               // read 4 characters
               dataPtr := add(dataPtr, 4)
               let input := mload(dataPtr)

               // write 3 bytes
               let output := add(
                   add(
                       shl(18, and(mload(add(tablePtr, and(shr(24, input), 0xFF))), 0xFF)),
                       shl(12, and(mload(add(tablePtr, and(shr(16, input), 0xFF))), 0xFF))),
                   add(
                       shl( 6, and(mload(add(tablePtr, and(shr( 8, input), 0xFF))), 0xFF)),
                               and(mload(add(tablePtr, and(        input , 0xFF))), 0xFF)
                    )
                )
                mstore(resultPtr, shl(232, output))
                resultPtr := add(resultPtr, 3)
            }
        }

        return result;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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: contracts/interfaces/IBalloonToken.sol



// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity ^0.8.3;

/*
 ▄████▄   ██▀███   ▄▄▄      ▒███████▒▓██   ██▓
▒██▀ ▀█  ▓██ ▒ ██▒▒████▄    ▒ ▒ ▒ ▄▀░ ▒██  ██▒
▒▓█    ▄ ▓██ ░▄█ ▒▒██  ▀█▄  ░ ▒ ▄▀▒░   ▒██ ██░
▒▓▓▄ ▄██▒▒██▀▀█▄  ░██▄▄▄▄██   ▄▀▒   ░  ░ ▐██▓░
▒ ▓███▀ ░░██▓ ▒██▒ ▓█   ▓██▒▒███████▒  ░ ██▒▓░
░ ░▒ ▒  ░░ ▒▓ ░▒▓░ ▒▒   ▓▒█░░▒▒ ▓░▒░▒   ██▒▒▒
  ░  ▒     ░▒ ░ ▒░  ▒   ▒▒ ░░░▒ ▒ ░ ▒ ▓██ ░▒░
░          ░░   ░   ░   ▒   ░ ░ ░ ░ ░ ▒ ▒ ░░
░ ░         ░           ░  ░  ░ ░     ░ ░
░                           ░         ░ ░
 ▄████▄   ██▓     ▒█████   █     █░ ███▄    █   ██████
▒██▀ ▀█  ▓██▒    ▒██▒  ██▒▓█░ █ ░█░ ██ ▀█   █ ▒██    ▒
▒▓█    ▄ ▒██░    ▒██░  ██▒▒█░ █ ░█ ▓██  ▀█ ██▒░ ▓██▄
▒▓▓▄ ▄██▒▒██░    ▒██   ██░░█░ █ ░█ ▓██▒  ▐▌██▒  ▒   ██▒
▒ ▓███▀ ░░██████▒░ ████▓▒░░░██▒██▓ ▒██░   ▓██░▒██████▒▒
░ ░▒ ▒  ░░ ▒░▓  ░░ ▒░▒░▒░ ░ ▓░▒ ▒  ░ ▒░   ▒ ▒ ▒ ▒▓▒ ▒ ░
  ░  ▒   ░ ░ ▒  ░  ░ ▒ ▒░   ▒ ░ ░  ░ ░░   ░ ▒░░ ░▒  ░ ░
░          ░ ░   ░ ░ ░ ▒    ░   ░     ░   ░ ░ ░  ░  ░
░ ░          ░  ░    ░ ░      ░             ░       ░
░

Crazy Clowns Insane Asylum
2021, V1.1
https://ccia.io
*/

interface IBalloonToken {
  function DEFAULT_ADMIN_ROLE() external view returns (bytes32);

  function DOMAIN_SEPARATOR() external view returns (bytes32);

  function MINTER_ROLE() external view returns (bytes32);

  function addMinterRole(address _address) external;

  function allowance(address owner, address spender) external view returns (uint256);

  function approve(address spender, uint256 amount) external returns (bool);

  function balanceOf(address account) external view returns (uint256);

  function burn(address account, uint256 amount) external;

  // function checkpoints ( address account, uint32 pos ) external view returns ( tuple );
  function decimals() external view returns (uint8);

  function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);

  function delegate(address delegatee) external;

  function delegateBySig(
    address delegatee,
    uint256 nonce,
    uint256 expiry,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external;

  function delegates(address account) external view returns (address);

  function getPastTotalSupply(uint256 blockNumber) external view returns (uint256);

  function getPastVotes(address account, uint256 blockNumber) external view returns (uint256);

  function getRoleAdmin(bytes32 role) external view returns (bytes32);

  function getVotes(address account) external view returns (uint256);

  function grantRole(bytes32 role, address account) external;

  function hasRole(bytes32 role, address account) external view returns (bool);

  function increaseAllowance(address spender, uint256 addedValue) external returns (bool);

  function mint(address to, uint256 amount) external;

  function name() external view returns (string memory);

  function nonces(address owner) external view returns (uint256);

  function numCheckpoints(address account) external view returns (uint32);

  // function owner (  ) external view returns ( address );
  function pause() external;

  function paused() external view returns (bool);

  function permit(
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external;

  function renounceOwnership() external;

  function renounceRole(bytes32 role, address account) external;

  function revokeRole(bytes32 role, address account) external;

  function supportsInterface(bytes4 interfaceId) external view returns (bool);

  function symbol() external view returns (string memory);

  function totalSupply() external view returns (uint256);

  function transfer(address recipient, uint256 amount) external returns (bool);

  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) external returns (bool);

  function transferOwnership(address newOwner) external;

  function unpause() external;
}

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



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

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @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/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @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);
}