// SPDX-License-Identifier: MIT
//  
//     ___                     _                 _                   
//    / _ \_ __ __ _ _ __   __| |_ __   __ _    /_\  _ __   ___  ___ 
//   / /_\/ '__/ _` | '_ \ / _` | '_ \ / _` |  //_\\| '_ \ / _ \/ __|
//  / /_\\| | | (_| | | | | (_| | |_) | (_| | /  _  \ |_) |  __/\__ \
//  \____/|_|  \__,_|_| |_|\__,_| .__/ \__,_| \_/ \_/ .__/ \___||___/
//                              |_|                 |_|              
//              __,__
//     .--.  .-"     "-.  .--.
//    / .. \/  .-. .-.  \/ .. \
//   | |  '|  /   Y   \  |'  | |
//   | \   \  \ 0 | 0 /  /   / |
//    \ '- ,\.-"`` ``"-./, -' /
//     `'-' /_   ^ ^   _\ '-'`
//         |  \._   _./  |
//         \   \ `~` /   /
//          '._ '-=-' _.'
//             '~---~'
//  
// File: @openzeppelin/contracts/utils/Context.sol


// 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/access/Ownable.sol


// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: @openzeppelin/contracts/security/Pausable.sol


// OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)

pragma solidity ^0.8.0;


/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol


// OpenZeppelin Contracts (last updated v4.5.0) (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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol


// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;


/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, 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}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, 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}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, 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) {
        address owner = _msgSender();
        _approve(owner, spender, _allowances[owner][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) {
        address owner = _msgSender();
        uint256 currentAllowance = _allowances[owner][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, 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:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, 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 Spend `amount` form the allowance of `owner` toward `spender`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol


// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol)

pragma solidity ^0.8.0;



/**
 * @dev Extension of {ERC20} that allows token holders to destroy both their own
 * tokens and those that they have an allowance for, in a way that can be
 * recognized off-chain (via event analysis).
 */
abstract contract ERC20Burnable is Context, ERC20 {
    /**
     * @dev Destroys `amount` tokens from the caller.
     *
     * See {ERC20-_burn}.
     */
    function burn(uint256 amount) public virtual {
        _burn(_msgSender(), amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
     * allowance.
     *
     * See {ERC20-_burn} and {ERC20-allowance}.
     *
     * Requirements:
     *
     * - the caller must have allowance for ``accounts``'s tokens of at least
     * `amount`.
     */
    function burnFrom(address account, uint256 amount) public virtual {
        _spendAllowance(account, _msgSender(), amount);
        _burn(account, amount);
    }
}

// File: contracts/Gramps.sol


pragma solidity ^0.8.4;
//  
//     ___                     _                 _                   
//    / _ \_ __ __ _ _ __   __| |_ __   __ _    /_\  _ __   ___  ___ 
//   / /_\/ '__/ _` | '_ \ / _` | '_ \ / _` |  //_\\| '_ \ / _ \/ __|
//  / /_\\| | | (_| | | | | (_| | |_) | (_| | /  _  \ |_) |  __/\__ \
//  \____/|_|  \__,_|_| |_|\__,_| .__/ \__,_| \_/ \_/ .__/ \___||___/
//                              |_|                 |_|              
//              __,__
//     .--.  .-"     "-.  .--.
//    / .. \/  .-. .-.  \/ .. \
//   | |  '|  /   Y   \  |'  | |
//   | \   \  \ 0 | 0 /  /   / |
//    \ '- ,\.-"`` ``"-./, -' /
//     `'-' /_   ^ ^   _\ '-'`
//         |  \._   _./  |
//         \   \ `~` /   /
//          '._ '-=-' _.'
//             '~---~'
//  





contract Gramps is ERC20, ERC20Burnable, Pausable, Ownable {

  uint256 public costToBuy = 1000000000000 wei;
  uint256 public tokenSellValue = 900000000000 wei;
  uint256 public reserveAmount = 100000;
  uint256 public reserveEth = 1000000000000000000 wei;
  bool public mintStatus = false;
  bool public claimTokensStatus = false;
  bool public buyTokensStatus = false;
  bool public sellTokensStatus = false;
  bool public sendTokensBackStatus = false;
  mapping(string => bytes32) public signatures;
  event tokensClaimed(address indexed _by, string indexed nftTokenId, uint _amount);
  event tokensBought(address indexed _by, uint256 _eth, uint256 _amount);
  event tokensSold(address indexed _by, uint256 _amount, uint256 amountOfETHToTransfer);

    constructor(uint256 initialSupply) ERC20("Gramps", "GRAMPS") {
	 _mint(address(this), initialSupply);
	}

	// Pause
    function pause() public onlyOwner {
        _pause();
    }

	// Unpause
    function unpause() public onlyOwner {
        _unpause();
    }

	// Owner Mint
    function mint(address to, uint256 amount) public onlyOwner {
     require(mintStatus, "Minting is not allowed at the moment.");
     _mint(to, amount);
    }

	// Before Token Transfer
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal whenNotPaused override
    {
	 super._beforeTokenTransfer(from, to, amount);
    }
	
    // Auth
	//
	// DEVELOPED BY gallaghersean.eth
	// ATTENTION: If you would like to use this function in your contract, send 1 eth to gallaghersean.eth and you'll receive the rights to use the function AND 2 hours of development time to help implementing it.
	// (c) Copyright 2022 gallaghersean.eth All Rights Reserved
	//
    function auth(string memory nftTokenId, string memory privateKey, bytes32 newSignature) internal {
     require(signatures[nftTokenId] != "","Authentication failed!");
	 bytes32 signature = keccak256(abi.encodePacked(nftTokenId,privateKey));
     require(signatures[nftTokenId] == signature,"Authentication failed!");
	 signatures[nftTokenId] = newSignature;
    }
	
	// Update Signatures
	function updateSignatures(string[] calldata nftTokenIds, bytes32[] calldata _signatures) public onlyOwner {
     for (uint256 i=0; i < nftTokenIds.length; i++) {
	  string memory nftTokenId = nftTokenIds[i];
	  bytes32 signature = _signatures[i];
	  signatures[nftTokenId] = signature;
	 }
	}
	
	// Claim Tokens
	function claimTokens(uint _amount, string memory nftTokenId, string memory privateKey, bytes32 newSignature) public {
     require(claimTokensStatus, "Claiming tokens is not active at the moment.");
	 auth(nftTokenId,privateKey,newSignature);
     require(_amount > 0, "You have to claim at least 1 token.");
     uint256 contractBalance = ERC20(address(this)).balanceOf(address(this));
     require(contractBalance >= _amount, "Contract does not have enough tokens for you to claim right now.");
     require((contractBalance - _amount) >= reserveAmount, "Contract does not have enough tokens for you to claim right now.");
     (bool sent) = ERC20(address(this)).transfer(msg.sender, _amount);
     require(sent, "Failed to transfer tokens.");
     emit tokensClaimed(msg.sender, nftTokenId, _amount);
	}
	
	// Buy Tokens
	function buyTokens(uint256 _amount) public payable returns (uint256 _amountBought) {
     require(buyTokensStatus, "Buying tokens is not active at the moment.");
	 if (msg.sender != owner()) {
      require(msg.value > 0, "Send ETH to buy some tokens.");
      uint256 ethCost = costToBuy * _amount;
      require(msg.value >= ethCost, "Not enough ETH to buy tokens.");
      uint256 contractBalance = ERC20(address(this)).balanceOf(address(this));
      require(contractBalance >= _amount, "Contract does not have enough tokens for your purchase.");
      require((contractBalance - _amount) >= reserveAmount, "Contract does not have enough tokens for your purchase.");
	 }
     (bool sent) = ERC20(address(this)).transfer(msg.sender, _amount);
     require(sent, "Failed to transfer tokens.");
     emit tokensBought(msg.sender, msg.value, _amount);
     return _amount;
	}

	// Sell Tokens
    function sellTokens(uint256 _amount) public {
     require(sellTokensStatus, "Selling tokens is not active at the moment.");
     require(_amount > 0, "Specify an amount of tokens greater than zero.");
     uint256 userBalance = ERC20(address(this)).balanceOf(msg.sender);
     require(userBalance >= _amount, "Your balance is lower than the amount of tokens you want to sell.");
     uint256 amountOfETHToTransfer = _amount * tokenSellValue;
     uint256 contractETHBalance = address(this).balance;
     require(contractETHBalance >= amountOfETHToTransfer, "Contract does not have enough funds to accept the sell request.");
     require((contractETHBalance - reserveEth) >= amountOfETHToTransfer, "Contract does not have enough funds to accept the sell request.");
	 approve(address(this), _amount);
     (bool sent) = ERC20(address(this)).transferFrom(msg.sender, address(this), _amount);
     require(sent, "Failed to transfer tokens.");
     (sent,) = msg.sender.call{value: amountOfETHToTransfer}("");
     require(sent, "Failed to send ETH.");
     emit tokensSold(msg.sender, _amount, amountOfETHToTransfer);
    }
	
	// Send Tokens Back to Contract
	function sendTokensBack(uint256 _amount) public {
     require(sendTokensBackStatus, "Sending tokens back is not active at the moment.");
     require(_amount > 0, "Specify an amount of tokens greater than zero.");
     uint256 userBalance = ERC20(address(this)).balanceOf(msg.sender);
     require(userBalance >= _amount, "Your balance is lower than the amount of tokens needed.");
	 approve(address(this), _amount);
     (bool sent) = ERC20(address(this)).transferFrom(msg.sender, address(this), _amount);
     require(sent, "Failed to transfer tokens.");
	}
	
	// Get Status
    function getStatus(string memory _type) public view returns (bool _status) {
	 if(compare(_type,"claimTokens")) { _status = claimTokensStatus; }
	 else if(compare(_type,"buyTokens")) { _status = buyTokensStatus; }
	 else if(compare(_type,"sellTokens")) { _status = sellTokensStatus; }
	 else if(compare(_type,"sendTokensBack")) { _status = sendTokensBackStatus; }
     return _status;
	}
	
	// Set Status
    function setStatus(string[] calldata _type, bool[] calldata _status) public onlyOwner {
     for (uint i=0; i < _type.length; i++) {
	  if(compare(_type[i],"mint")) { mintStatus = _status[i]; }
	  else if(compare(_type[i],"claimTokens")) { claimTokensStatus = _status[i]; }
	  else if(compare(_type[i],"buyTokens")) { buyTokensStatus = _status[i]; }
	  else if(compare(_type[i],"sellTokens")) { sellTokensStatus = _status[i]; }
	  else if(compare(_type[i],"sendTokensBack")) { sendTokensBackStatus = _status[i]; }
     }
	}
	
	// Change Values for costToBuy and tokenSellValue and reserveAmount
	function changeVars(string[] calldata _vars,uint256[] calldata _amounts) public onlyOwner {
     for (uint i=0; i < _vars.length; i++) {
	  if(compare(_vars[i],"costToBuy")) { costToBuy = _amounts[i]; }
	  else if(compare(_vars[i],"tokenSellValue")) { tokenSellValue = _amounts[i]; }
	  else if(compare(_vars[i],"reserveAmount")) { reserveAmount = _amounts[i]; }
      else if(compare(_vars[i],"reserveEth")) { reserveEth = _amounts[i]; }
	 }
	}
	
	// Withdraw Exact Amount
	function withdrawAmount(uint256 _amount) public onlyOwner {
     uint256 ownerBalance = address(this).balance;
     require(ownerBalance >= _amount, "The contract does not have enough of a balance to withdraw.");
     (bool sent,) = msg.sender.call{value: _amount}("");
     require(sent, "Failed to send withdraw.");
    }
	
	// Withdraw
	function withdraw() public onlyOwner {
     uint256 ownerBalance = address(this).balance;
     require(ownerBalance > 0, "The contract does not have a balance to withdraw.");
     (bool sent,) = msg.sender.call{value: address(this).balance}("");
     require(sent, "Failed to send withdraw.");
    }
   
    // Compare Strings
    function compare(string memory a, string memory b) public pure returns(bool) {
     return keccak256(abi.encodePacked(a)) == keccak256(abi.encodePacked(b));
    }
}