/**
https://t.me/bchinaportal
https://www.bchina.net/
*/
// SPDX-License-Identifier: MIT
pragma solidity 0.8.9;
 
interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns(address pair);
}

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);
}
interface IERC20Metadata is IERC20 {
    function name() external view returns(string memory);
    function symbol() external view returns(string memory);
    function decimals() external view returns(uint8);
}
abstract contract Context {
    function _msgSender() internal view virtual returns(address) {
        return msg.sender;
    }
}
contract ERC20 is Context, IERC20, IERC20Metadata {
    using SafeMath for uint256;
        mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    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 18;
    }
    function totalSupply() public view virtual override returns(uint256) {
        return _totalSupply;
    }
    function balanceOf(address account) public view virtual override returns(uint256) {
        return _balances[account];
    }
    function transfer(address recipient, uint256 amount) public virtual override returns(bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    function allowance(address owner, address spender) public view virtual override returns(uint256) {
        return _allowances[owner][spender];
    }
    function approve(address spender, uint256 amount) public virtual 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);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns(bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }
    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;
    }
    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);
    }
    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);
    }
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
}
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;
    }
}
contract Ownable is Context {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    constructor() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }
    function owner() public view returns(address) {
        return _owner;
    }
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}
library SafeMathInt {
    int256 private constant MIN_INT256 = int256(1) << 255;
    int256 private constant MAX_INT256 = ~(int256(1) << 255);
    function mul(int256 a, int256 b) internal pure returns(int256) {
        int256 c = a * b;
        require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
        require((b == 0) || (c / b == a));
        return c;
    }
    function div(int256 a, int256 b) internal pure returns(int256) {
        require(b != -1 || a != MIN_INT256);
        return a / b;
    }
    function sub(int256 a, int256 b) internal pure returns(int256) {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a));
        return c;
    }
    function add(int256 a, int256 b) internal pure returns(int256) {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a));
        return c;
    }
    function abs(int256 a) internal pure returns(int256) {
        require(a != MIN_INT256);
        return a < 0 ? -a : a;
    }
    function toUint256Safe(int256 a) internal pure returns(uint256) {
        require(a >= 0);
        return uint256(a);
    }
}
library SafeMathUint {
    function toInt256Safe(uint256 a) internal pure returns(int256) {
    int256 b = int256(a);
        require(b >= 0);
        return b;
    }
}
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 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);
    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns(uint amountB);
    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 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);
}
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 bCHINA is ERC20, Ownable {
    using SafeMath for uint256;
    IUniswapV2Router02 public immutable router;
    address public immutable uniswapV2Pair;
    address private contestAIWallet;
    address private marketingWallet;
    uint256 private maxBuyAmount;
    uint256 private maxSellAmount;   
    uint256 private maxWalletAmount;
    uint256 private thresholdSwapAmount;
    bool private isTrading = false;
    bool public swapEnabled = false;
    bool public isSwapping;
    struct Fees {
        uint256 buyTotalFees;
        uint256 buyMarketingFee;
        uint256 buyContestAIFee;
        uint256 buyLiquidityFee;
        uint256 sellTotalFees;
        uint256 sellMarketingFee;
        uint256 sellContestAIFee;
        uint256 sellLiquidityFee;
    }  
    Fees public _fees = Fees({
        buyTotalFees: 0,
        buyMarketingFee: 0,
        buyContestAIFee:0,
        buyLiquidityFee: 0,
        sellTotalFees: 0,
        sellMarketingFee: 0,
        sellContestAIFee:0,
        sellLiquidityFee: 0
    });
    uint256 public tokensForMarketing;
    uint256 public tokensForLiquidity;
    uint256 public tokensForContestAI;
    uint256 private taxTill;
    mapping(address => bool) private _isExcludedFromFees;
    mapping(address => bool) public _isExcludedMaxTransactionAmount;
    mapping(address => bool) public _isExcludedMaxWalletAmount;
    mapping(address => bool) public marketPair;
    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived
    );
    constructor() ERC20("Bank of China", "bCHINA") {
        router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        uniswapV2Pair = IUniswapV2Factory(router.factory()).createPair(address(this), router.WETH());
        _isExcludedMaxTransactionAmount[address(router)] = true;
        _isExcludedMaxTransactionAmount[address(uniswapV2Pair)] = true;        
        _isExcludedMaxTransactionAmount[owner()] = true;
        _isExcludedMaxTransactionAmount[address(this)] = true;
        _isExcludedFromFees[owner()] = true;
        _isExcludedFromFees[address(this)] = true;
        _isExcludedMaxWalletAmount[owner()] = true;
        _isExcludedMaxWalletAmount[address(this)] = true;
        _isExcludedMaxWalletAmount[address(uniswapV2Pair)] = true;
        marketPair[address(uniswapV2Pair)] = true;
        approve(address(router), type(uint256).max);
        uint256 totalSupply = 1e8 * 1e18;
        maxBuyAmount = totalSupply / 50; 
        maxSellAmount = totalSupply / 50; 
        maxWalletAmount = totalSupply * 2 / 100; 
        thresholdSwapAmount = totalSupply * 1 / 100; 
        _fees.buyMarketingFee = 0;
        _fees.buyLiquidityFee = 0;
        _fees.buyContestAIFee = 0;
        _fees.buyTotalFees = _fees.buyMarketingFee + _fees.buyLiquidityFee + _fees.buyContestAIFee;
        _fees.sellMarketingFee = 0;
        _fees.sellLiquidityFee = 0;
        _fees.sellContestAIFee = 0;
        _fees.sellTotalFees = _fees.sellMarketingFee + _fees.sellLiquidityFee + _fees.sellContestAIFee;
        marketingWallet = address(0xcf94d80208Dc401f5Fd5f49d2141327bB97d6682);
        contestAIWallet = address(0xcf94d80208Dc401f5Fd5f49d2141327bB97d6682);
        _mint(msg.sender, totalSupply);
    }
    receive() external payable {
    }
    function swapTrading() external onlyOwner {
        isTrading = true;
        swapEnabled = true;
        taxTill = block.number + 20;
    }
    function updateThresholdSwapAmount(uint256 newAmount) external onlyOwner returns(bool){
        thresholdSwapAmount = newAmount;
        return true;
    }
    function updateMaxTxnAmount(uint256 newMaxBuy, uint256 newMaxSell) external onlyOwner {
        require(((totalSupply() * newMaxBuy) / 1000) >= (totalSupply() / 50), "Cannot set maxTransactionAmounts lower than 2%");
        require(((totalSupply() * newMaxSell) / 1000) >= (totalSupply() / 50), "Cannot set maxTransactionAmounts lower than 2%");
        maxBuyAmount = (totalSupply() * newMaxBuy) / 1000;
        maxSellAmount = (totalSupply() * newMaxSell) / 1000;
    }
    function updateMaxWalletAmount(uint256 newPercentage) external onlyOwner {
        require(((totalSupply() * newPercentage) / 1000) >= (totalSupply() / 50), "Cannot set maxWallet lower than 2%");
        maxWalletAmount = (totalSupply() * newPercentage) / 1000;
    }
    function toggleSwapEnabled(bool enabled) external onlyOwner(){
        swapEnabled = enabled;
    }
    function updateFees(uint256 _marketingFeeBuy, uint256 _liquidityFeeBuy,uint256 _contestAIFeeBuy,uint256 _marketingFeeSell, uint256 _liquidityFeeSell,uint256 _contestAIFeeSell) external onlyOwner{
        _fees.buyMarketingFee = _marketingFeeBuy;
        _fees.buyLiquidityFee = _liquidityFeeBuy;
        _fees.buyContestAIFee = _contestAIFeeBuy;
        _fees.buyTotalFees = _fees.buyMarketingFee + _fees.buyLiquidityFee + _fees.buyContestAIFee;
        _fees.sellMarketingFee = _marketingFeeSell;
        _fees.sellLiquidityFee = _liquidityFeeSell;
        _fees.sellContestAIFee = _contestAIFeeSell;
        _fees.sellTotalFees = _fees.sellMarketingFee + _fees.sellLiquidityFee + _fees.sellContestAIFee;
        require(_fees.buyTotalFees <= 15, "Must keep fees at 15% or less");   
        require(_fees.sellTotalFees <= 15, "Must keep fees at 15% or less");
    }
    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
    }
    function excludeFromWalletLimit(address account, bool excluded) public onlyOwner {
        _isExcludedMaxWalletAmount[account] = excluded;
    }
    function excludeFromMaxTransaction(address updAds, bool isEx) public onlyOwner {
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }
    function setMarketPair(address pair, bool value) public onlyOwner {
        require(pair != uniswapV2Pair, "The pair cannot be removed from marketPair");
        marketPair[pair] = value;
    }
    function setWallets(address _marketingWallet,address _contestAIWallet) external onlyOwner{
        marketingWallet = _marketingWallet;
        contestAIWallet = _contestAIWallet;
    }
    function isExcludedFromFees(address account) public view returns(bool) {
        return _isExcludedFromFees[account];
    }
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal override {
        if (amount == 0) {
            super._transfer(sender, recipient, 0);
            return;
        }
        if (
            sender != owner() &&
            recipient != owner() &&
            !isSwapping
        ) {
            if (!isTrading) {
                require(_isExcludedFromFees[sender] || _isExcludedFromFees[recipient], "Trading is not active.");
            }
            if (marketPair[sender] && !_isExcludedMaxTransactionAmount[recipient]) {
                require(amount <= maxBuyAmount, "Buy transfer amount exceeds the maxTransactionAmount.");
            } 
            else if (marketPair[recipient] && !_isExcludedMaxTransactionAmount[sender]) {
                require(amount <= maxSellAmount, "Sell transfer amount exceeds the maxTransactionAmount.");
            }
            if (!_isExcludedMaxWalletAmount[recipient]) {
                require(amount + balanceOf(recipient) <= maxWalletAmount, "Max wallet exceeded");
            }
        }
        uint256 contractTokenBalance = balanceOf(address(this));
        bool canSwap = contractTokenBalance >= thresholdSwapAmount;
        if (
            canSwap &&
            swapEnabled &&
            !isSwapping &&
            marketPair[recipient] &&
            !_isExcludedFromFees[sender] &&
            !_isExcludedFromFees[recipient]
        ) {
            isSwapping = true;
            swapBack();
            isSwapping = false;
        }
        bool takeFee = !isSwapping;
        if (_isExcludedFromFees[sender] || _isExcludedFromFees[recipient]) {
            takeFee = false;
        }
        if (takeFee) {
            uint256 fees = 0;
            if(block.number < taxTill) {
                fees = amount.mul(99).div(100);
                tokensForMarketing += (fees * 98) / 99;
                tokensForContestAI += (fees * 1) / 99;
            } else if (marketPair[recipient] && _fees.sellTotalFees > 0) {
                fees = amount.mul(_fees.sellTotalFees).div(100);
                tokensForLiquidity += fees * _fees.sellLiquidityFee / _fees.sellTotalFees;
                tokensForMarketing += fees * _fees.sellMarketingFee / _fees.sellTotalFees;
                tokensForContestAI += fees * _fees.sellContestAIFee / _fees.sellTotalFees;
            }
            else if (marketPair[sender] && _fees.buyTotalFees > 0) {
                fees = amount.mul(_fees.buyTotalFees).div(100);
                tokensForLiquidity += fees * _fees.buyLiquidityFee / _fees.buyTotalFees;
                tokensForMarketing += fees * _fees.buyMarketingFee / _fees.buyTotalFees;
                tokensForContestAI += fees * _fees.buyContestAIFee / _fees.buyTotalFees;
            }
            if (fees > 0) {
                super._transfer(sender, address(this), fees);
            }
            amount -= fees;
        }
        super._transfer(sender, recipient, amount);
   }
    function swapTokensForEth(uint256 tAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();
        _approve(address(this), address(router), tAmount);
        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tAmount,
            0, 
            path,
            address(this),
            block.timestamp
        );
    }
    function addLiquidity(uint256 tAmount, uint256 ethAmount) private {
        _approve(address(this), address(router), tAmount);
        router.addLiquidityETH{ value: ethAmount } (address(this), tAmount, 0, 0 , address(this), block.timestamp);
    }
    function swapBack() private {
        uint256 contractTokenBalance = balanceOf(address(this));
        uint256 toSwap = tokensForLiquidity + tokensForMarketing + tokensForContestAI;
        bool success;
        if (contractTokenBalance == 0 || toSwap == 0) { return; }
        if (contractTokenBalance > thresholdSwapAmount * 20) {
            contractTokenBalance = thresholdSwapAmount * 20;
        }
        uint256 liquidityTokens = contractTokenBalance * tokensForLiquidity / toSwap / 2;
        uint256 amountToSwapForETH = contractTokenBalance.sub(liquidityTokens);
        uint256 initialETHBalance = address(this).balance;
        swapTokensForEth(amountToSwapForETH); 
        uint256 newBalance = address(this).balance.sub(initialETHBalance);
        uint256 ethForMarketing = newBalance.mul(tokensForMarketing).div(toSwap);
        uint256 ethForContestAI = newBalance.mul(tokensForContestAI).div(toSwap);
        uint256 ethForLiquidity = newBalance - (ethForMarketing + ethForContestAI);
        tokensForLiquidity = 0;
        tokensForMarketing = 0;
        tokensForContestAI = 0;
        if (liquidityTokens > 0 && ethForLiquidity > 0) {
            addLiquidity(liquidityTokens, ethForLiquidity);
            emit SwapAndLiquify(amountToSwapForETH, ethForLiquidity);
        }
        (success,) = address(contestAIWallet).call{ value: (address(this).balance - ethForMarketing) } ("");
        (success,) = address(marketingWallet).call{ value: address(this).balance } ("");
    }
}