/**
/**
// SPDX-License-Identifier: NOLICENSE

/**

Token Name: Great Wall of China
Ticker: 长城
Supply: 1,000,000

The Great Wall of China was built over centuries by China’s emperors to protect their territory. 

As the Chinese Ethereum doing good, we are inspired to build our own Wall and Territory as a solid community. 

Building our own green wall.

TG: https://t.me/GWOC_ERC20
TWITTER: https://twitter.com/GWOC_ERC20
WEBSITE: http://webuildthegreatwallofchina.com/

*/

pragma solidity ^0.8.4;

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, 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);
}

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;
        return c;
    }

    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;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        return c;
    }

}

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _setOwner(_msgSender());
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        _setOwner(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _setOwner(newOwner);
    }

    function _setOwner(address newOwner) private {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
    function getPair(address tokenA, address tokenB)  external view returns (address pair);
}

interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
}

contract GreatWallofChina is Context, IERC20, Ownable {

    using SafeMath for uint256;
    mapping (address => uint256) private _tOwned;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcludedFromFee;
    mapping (address => bool) private _isExcludedFromMaxWalletSize;

    string private constant _name = "Great Wall of China";
    string private constant _symbol = unicode"长城";
    uint8 private constant _decimals = 9;

    uint256 public buyAutoLiquidityFee = 0;
    uint256 public buyAutoBurnFee = 100;
    uint256 public buyMarketingFee = 200;
    uint256 public totalBuyFees = buyAutoLiquidityFee + buyAutoBurnFee + buyMarketingFee;

    uint256 public sellAutoLiquidityFee = 0;
    uint256 public sellAutoBurnFee = 100;
    uint256 public sellMarketingFee = 200;
    uint256 public totalSellFees =  sellAutoLiquidityFee + sellAutoBurnFee + sellMarketingFee;

    uint256 public tokensForAutoLiquidity;
    uint256 public tokensForAutoBurn;  
    uint256 public tokensForMarketing;
    uint16 public masterTaxDivisor = 10000;

    address public constant DEAD = 0x000000000000000000000000000000000000dEaD;
    address public pairAddress;
    
    IUniswapV2Router02 private uniswapV2Router;
    address private uniswapV2Pair;
    bool private tradingOpen;
    bool private inSwap = false;
    bool private swapEnabled = false;
    uint256 private _tTotal = 1000000 * 10**9;
    uint256 private maxWalletAmount = 20001 * 10**9;
    uint256 private maxTxAmount = 20001 * 10**9;
    address payable private feeAddrWallet;

    event MaxWalletAmountUpdated(uint maxWalletAmount);

    modifier lockTheSwap {
        inSwap = true;
        _;
        inSwap = false;
    }
  
    constructor () {
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        uniswapV2Router = _uniswapV2Router;
        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
        pairAddress = IUniswapV2Factory(_uniswapV2Router.factory()).getPair(address(this), _uniswapV2Router.WETH());
        feeAddrWallet = payable(0x42B7456B7460D68a6E4053077f9D4088a35068eD);    
        _tOwned[owner()] = _tTotal;  

        uint256 _buyAutoLiquidityFee = 0;
        uint256 _buyAutoBurnFee = 100;
        uint256 _buyMarketingFee = 1000;
        uint256 _sellAutoLiquidityFee = 0;
        uint256 _sellAutoBurnFee = 100;
        uint256 _sellMarketingFee = 3000;
        
        buyAutoLiquidityFee = _buyAutoLiquidityFee;
        buyAutoBurnFee = _buyAutoBurnFee;
        buyMarketingFee = _buyMarketingFee;
        totalBuyFees = buyAutoLiquidityFee + buyAutoBurnFee + buyMarketingFee;
        
        sellAutoLiquidityFee = _sellAutoLiquidityFee;
        sellAutoBurnFee = _sellAutoBurnFee;
        sellMarketingFee = _sellMarketingFee;
        totalSellFees = sellAutoLiquidityFee + sellAutoBurnFee + sellMarketingFee;      

        _isExcludedFromFee[owner()] = true;
        _isExcludedFromFee[address(this)] = true;
        _isExcludedFromFee[feeAddrWallet] = true;
        _isExcludedFromMaxWalletSize[owner()] = true;
        _isExcludedFromMaxWalletSize[address(this)] = true;
        _isExcludedFromMaxWalletSize[feeAddrWallet] = true;     
        emit Transfer(address(0), owner(), _tTotal);
    }

    function name() public pure returns (string memory) { return _name; }
    function symbol() public pure returns (string memory) { return _symbol; }
    function decimals() public pure returns (uint8) { return _decimals; }
    function totalSupply() public view override returns (uint256) { return _tTotal; }
    function balanceOf(address account) public view override returns (uint256) { return _tOwned[account]; }
    function transfer(address recipient, uint256 amount) public override returns (bool) { _transfer(_msgSender(), recipient, amount); return true; }
    function allowance(address owner, address spender) public view override returns (uint256) { return _allowances[owner][spender]; }
    function approve(address spender, uint256 amount) public override returns (bool) { _approve(_msgSender(), spender, amount); return true; }

    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");
        _approve(sender, _msgSender(), currentAllowance - amount);
        return true;
    }

    function _approve(address owner, address spender, uint256 amount) private {
        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);
    }

    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");
        require(amount <= balanceOf(from),"You are trying to transfer more than your balance");    
        require(tradingOpen || _isExcludedFromFee[from] || _isExcludedFromFee[to], "Trading not enabled yet");

        if (from == uniswapV2Pair && to != address(uniswapV2Router) && ! _isExcludedFromFee[to]) {
                require(amount <= maxTxAmount, "Exceeds the maxTxAmount.");
        }

      if (from == uniswapV2Pair && to != address(uniswapV2Router) && ! _isExcludedFromMaxWalletSize[to]) {             
                require(amount + balanceOf(to) <= maxWalletAmount, "Recipient exceeds max wallet size.");
        }

        uint256 contractTokenBalance = balanceOf(address(this));
            if (!inSwap && from != uniswapV2Pair && swapEnabled && contractTokenBalance>0) {
                swapTokensForEth(contractTokenBalance);
                uint256 contractETHBalance = address(this).balance;
                if(contractETHBalance > 0) {
                    sendETHToFee(address(this).balance);
                }
            }

        _tokenTransfer(from, to, amount, !(_isExcludedFromFee[from] || _isExcludedFromFee[to]));
    }

    function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function _tokenTransfer(address sender, address recipient, uint256 amount, bool takeFee) private {
        _tOwned[sender] -= amount;
        uint256 amountReceived = (takeFee) ? takeTaxes(sender, recipient, amount) : amount;
        _tOwned[recipient] += amountReceived;
        emit Transfer(sender, recipient, amountReceived);
    }

    function takeTaxes(address from, address to, uint256 amount) internal returns (uint256) {
        if(from == uniswapV2Pair && totalBuyFees > 0 ) { 
            tokensForAutoLiquidity = amount * buyAutoLiquidityFee / masterTaxDivisor;
            tokensForAutoBurn = amount * buyAutoBurnFee / masterTaxDivisor;         
            tokensForMarketing = amount * buyMarketingFee / masterTaxDivisor;    
        } else if (to == uniswapV2Pair  && totalSellFees > 0 ) { 
            tokensForAutoLiquidity = amount * sellAutoLiquidityFee / masterTaxDivisor;
            tokensForAutoBurn = amount * sellAutoBurnFee / masterTaxDivisor;
            tokensForMarketing = amount * sellMarketingFee / masterTaxDivisor;        
        }
        _tOwned[pairAddress] += tokensForAutoLiquidity;
        emit Transfer(from, pairAddress, tokensForAutoLiquidity);
        
        _tOwned[DEAD] += tokensForAutoBurn;
        _tTotal = _tTotal - tokensForAutoBurn;
        _tTotal = totalSupply();
        emit Transfer(from, DEAD, tokensForAutoBurn);
                
        _tOwned[address(this)] += tokensForMarketing;
        emit Transfer(from, address(this), tokensForMarketing);

        uint256 feeAmount = tokensForAutoLiquidity + tokensForAutoBurn + tokensForMarketing;
        return amount - feeAmount;
    }

    function excludeFromFee(address account) public onlyOwner {
        _isExcludedFromFee[account] = true;
    }

    function includeInFee(address account) public onlyOwner {
        _isExcludedFromFee[account] = false;
    }

    function excludeFromMaxWalletLimit(address account) public onlyOwner {
		_isExcludedFromMaxWalletSize[account] = true;
	}

    function includeInMaxWalletLimit(address account) public onlyOwner {
		_isExcludedFromMaxWalletSize[account] = false;
	}

    function setWalletandTxtAmount(uint256 _maxTxAmount, uint256 _maxWalletSize) external onlyOwner{
        maxTxAmount = _maxTxAmount * 10 **_decimals;
        maxWalletAmount = _maxWalletSize * 10 **_decimals;
    }

    function updateMaxWallet(uint256 _maxWalletSize) external onlyOwner{
        maxWalletAmount = _maxWalletSize * 10 **_decimals;
    }

    function updateMaxTxtAmount(uint256 _maxTxAmount) external onlyOwner{
        maxTxAmount = _maxTxAmount * 10 **_decimals;
    }
    function RervertSellFeesToOriginalTax() external onlyOwner {
        //Original state of sell tax
        sellAutoLiquidityFee = 0;
        sellAutoBurnFee = 100;
        sellMarketingFee = 200;
        totalSellFees = sellAutoLiquidityFee + sellAutoBurnFee + sellMarketingFee;
    }
    function RervertBuyFeesToOriginalTax() external onlyOwner {
        //Original state of buy tax
        buyAutoLiquidityFee = 0;
        buyAutoBurnFee = 100;
        buyMarketingFee = 200;
       totalBuyFees = buyAutoLiquidityFee + buyAutoBurnFee + buyMarketingFee;
           }

    function sendETHToFee(uint256 amount) private {
        feeAddrWallet.transfer(amount); 
    } 

    function openTrading() external onlyOwner() {
        require(!tradingOpen,"trading is already open");        
        swapEnabled = true;
        maxWalletAmount = 20001 * 10**9;
        maxTxAmount = 20001 * 10**9;
        tradingOpen = true;
        IERC20(uniswapV2Pair).approve(address(uniswapV2Router), type(uint).max);
    }

    receive() external payable{
    }

}