SPX_STRATEGY

// SPDX-License-Identifier: MIT


// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router01.sol

pragma solidity >=0.6.2;

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);
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol

pragma solidity >=0.6.2;

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;
}

// File: @uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    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(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol

// OpenZeppelin Contracts (last updated v4.9.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

abstract contract ReentrancyGuard {
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        _status = _NOT_ENTERED;
    }

    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }
}

// File: main.sol

pragma solidity ^0.8.19;

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;
        }
    }
}

pragma solidity ^0.8.0; 

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);
}

pragma solidity ^0.8.0;

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
}

pragma solidity ^0.8.19;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

pragma solidity ^0.8.0;

contract ERC20 is Context, IERC20, IERC20Metadata {
    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);

        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 _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 _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 _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

pragma solidity ^0.8.19;

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);
    }
}

pragma solidity ^0.8.30;

contract SPX_STRATEGY is ERC20, Ownable, ReentrancyGuard {
    using SafeMath for uint256;

    IUniswapV2Router02 public immutable uniswapRouter;
    address public uniswapV2Pair;

    address constant public SPX_TOKEN = payable(0xc50673EDb3A7b94E8CAD8a7d4E0cD68864E33eDF);
    address constant public WETH_TOKEN = payable(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2);
    address constant public DEAD_ADDRESS = payable(0x000000000000000000000000000000000000dEaD);

    uint256 public profitThresholdBps = 1200;

    struct Order {
        uint256 ethSpent;
        uint256 spxBought;
        uint256 timestamp;
        bool sold; 
    }

    uint256 public nextOrderId = 1;
    mapping(uint256 => Order) public orders;

    uint256 public minSpxBuy = 5 ether;
    uint256 public txReward = 0.01 ether;
    uint256 public maxSlippageBps = 500; // 10% max slippage

    bool private swapping;

    address public treasuryWallet;
    address public teamWallet;

    uint256 public maxTransactionAmount;
    uint256 public swapTokensAtAmount;
    uint256 public maxWallet;

    bool public limitsInEffect = true;
    bool public tradingActive = false;
    bool public swapEnabled = false;

    uint256 public buyTotalFees;
    uint256 public buyTreasuryFee;

    uint256 public sellTotalFees;
    uint256 public sellTreasuryFee;

    uint256 public tokensForTreasury;

    mapping(address => bool) private _isExcludedFromFees;
    mapping(address => bool) public _isExcludedMaxTransactionAmount;
    mapping(address => bool) public automatedMarketMakerPairs;
    event UpdateUniswapRouter(address indexed newAddress, address indexed oldAddress);
    event ExcludeFromFees(address indexed account, bool isExcluded);
    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);
    event treasuryWalletUpdated(address indexed newWallet, address indexed oldWallet);

    constructor() ERC20("SPX Strategy", "SPXSTR") {
        IUniswapV2Router02 _uniswapRouter = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D 
        );

        excludeFromMaxTransaction(address(_uniswapRouter), true);
        uniswapRouter = _uniswapRouter;

        uint256 _buyTreasuryFee = 40;
        uint256 _sellTreasuryFee = 40;

        uint256 totalSupply = 1_000_000_000 * 1e18;

        maxTransactionAmount = totalSupply ;
        maxWallet = totalSupply ;
        swapTokensAtAmount = (totalSupply * 5) / 10000; 

        buyTreasuryFee = _buyTreasuryFee;
        buyTotalFees = buyTreasuryFee;

        sellTreasuryFee = _sellTreasuryFee;
        sellTotalFees = sellTreasuryFee;

        treasuryWallet = address(this);
        teamWallet = msg.sender;

        excludeFromFees(owner(), true);
        excludeFromFees(address(this), true);

        excludeFromMaxTransaction(owner(), true);
        excludeFromMaxTransaction(address(this), true);

        _mint(msg.sender, totalSupply);
    }

    receive() external payable {}

    function createPair() external onlyOwner {
        uniswapV2Pair = IUniswapV2Factory(uniswapRouter.factory())
            .createPair(address(this), uniswapRouter.WETH());
        excludeFromMaxTransaction(address(uniswapV2Pair), true);
        _setAutomatedMarketMakerPair(address(uniswapV2Pair), true);
    }

    function enableTrading() external onlyOwner {
        tradingActive = true;
        swapEnabled = true;
    }

    function removeLimits() external onlyOwner returns (bool) {
        limitsInEffect = false;
        return true;
    }

    function updateSwapTokensAtAmount(uint256 newAmount) external onlyOwner returns (bool) {
        swapTokensAtAmount = newAmount;
        return true;
    }

    function excludeFromMaxTransaction(address updAds, bool isEx) public onlyOwner {
        _isExcludedMaxTransactionAmount[updAds] = isEx;
    }

    function updateSwapEnabled(bool enabled) external onlyOwner {
        swapEnabled = enabled;
    }

    function updateBuyFees(uint256 _treasuryFee) external onlyOwner {
        buyTreasuryFee = _treasuryFee;
        buyTotalFees = buyTreasuryFee;
    }

    function updateSellFees(uint256 _treasuryFee) external onlyOwner {
        sellTreasuryFee = _treasuryFee;
        sellTotalFees = sellTreasuryFee;
    }

    function updateProfitThreshold(uint256 newBps) external onlyOwner {
    require(newBps >= 1000, "Minimum 0% profit (break-even)");
    require(newBps <= 5000, "Maximum 50% profit");
    profitThresholdBps = newBps;
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
        emit ExcludeFromFees(account, excluded);
    }

    function setAutomatedMarketMakerPair(address pair, bool value) public onlyOwner {
        require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs");
        _setAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;
        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function isExcludedFromFees(address account) public view returns (bool) {
        return _isExcludedFromFees[account];
    }

    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");

        if (amount == 0) {
            super._transfer(from, to, 0);
            return;
        }

        if (limitsInEffect) {
            if (from != owner() && to != owner() && to != address(0) && !swapping) {
                if (!tradingActive) {
                    require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
                }

                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) {
                    require(amount <= maxTransactionAmount, "Buy transfer amount exceeds the maxTransactionAmount.");
                    require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
                }
                else if (automatedMarketMakerPairs[to] && !_isExcludedMaxTransactionAmount[from]) {
                    require(amount <= maxTransactionAmount, "Sell transfer amount exceeds the maxTransactionAmount.");
                } else if (!_isExcludedMaxTransactionAmount[to]) {
                    require(amount + balanceOf(to) <= maxWallet, "Max wallet exceeded");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));
        bool canSwap = contractTokenBalance >= swapTokensAtAmount;

        if (canSwap && swapEnabled && !swapping && !automatedMarketMakerPairs[from] && 
            !_isExcludedFromFees[from] && !_isExcludedFromFees[to]) {
            swapping = true;
            swapBack();
            swapping = false;
        }

        bool takeFee = !swapping;

        if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }

        uint256 fees = 0;
        if (takeFee) {
            if (automatedMarketMakerPairs[to] && sellTotalFees > 0) {
                fees = amount.mul(sellTotalFees).div(100);
                tokensForTreasury += (fees * sellTreasuryFee) / sellTotalFees;
            }
            else if (automatedMarketMakerPairs[from] && buyTotalFees > 0) {
                fees = amount.mul(buyTotalFees).div(100);
                tokensForTreasury += (fees * buyTreasuryFee) / buyTotalFees;
            }

            if (fees > 0) {
                super._transfer(from, address(this), fees);
            }

            amount -= fees;
        }

        super._transfer(from, to, amount);
    }

    function swapTokensForEth(uint256 tokenAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapRouter.WETH();

        _approve(address(this), address(uniswapRouter), tokenAmount);

        uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForTreasury;
        bool success;

        if (contractBalance == 0 || totalTokensToSwap == 0) {
            return;
        }

        if (contractBalance > swapTokensAtAmount * 20) {
            contractBalance = swapTokensAtAmount * 20;
        }

        uint256 amountToSwapForETH = contractBalance;
        uint256 initialETHBalance = address(this).balance;
        swapTokensForEth(amountToSwapForETH);
        uint256 ethBalance = address(this).balance.sub(initialETHBalance);
        tokensForTreasury = 0;

        uint256 teamShare = ethBalance.mul(20).div(100);

        if (teamWallet != address(0)) {
            (success, ) = teamWallet.call{value: teamShare}("");
        }
    }

    /* SPX functions */

    function updateRewards(uint256 val) external onlyOwner {
        txReward = val;
    }

    function updateMinSpxBuy(uint256 val) external onlyOwner {
        minSpxBuy = val;
    }

    function updateMaxSlippage(uint256 bps) external onlyOwner {
        require(bps <= 1000, "Max 10% slippage");
        maxSlippageBps = bps;
    }

    function updateTeamWallet(address newWallet) external onlyOwner {
        require(newWallet != address(0), "Zero address not allowed");
        teamWallet = newWallet;
    }

    function buySpx() external nonReentrant {
        uint256 treasuryBalance = address(this).balance;
        require(treasuryBalance >= minSpxBuy + txReward, "Not enough ETH in treasury");

        uint256 ethToSpend = treasuryBalance - txReward;
        
        // Calculate minimum amount out with slippage protection
        address[] memory pathPreview = new address[](2);
        pathPreview[0] = uniswapRouter.WETH();
        pathPreview[1] = SPX_TOKEN;
        
        uint[] memory amountsExpected = uniswapRouter.getAmountsOut(ethToSpend, pathPreview);
        uint256 minAmountOut = amountsExpected[1].mul(10000 - maxSlippageBps).div(10000);

        uint256 beforeSpxBalance = IERC20(SPX_TOKEN).balanceOf(address(this));
        address[] memory path = new address[](2);
        path[0] = uniswapRouter.WETH();
        path[1] = SPX_TOKEN;

        uniswapRouter.swapExactETHForTokensSupportingFeeOnTransferTokens{value: ethToSpend}(
            minAmountOut, // Slippage protection
            path,
            address(this),
            block.timestamp
        );
        
        uint256 afterSpxBalance = IERC20(SPX_TOKEN).balanceOf(address(this));
        uint256 spxBought = afterSpxBalance - beforeSpxBalance;

        uint256 orderId = nextOrderId++;
        orders[orderId] = Order({
            ethSpent: ethToSpend,
            spxBought: spxBought,
            timestamp: block.timestamp,
            sold: false
        });

        payable(msg.sender).transfer(txReward);
    }

    function sellSpx(uint256 orderId) external nonReentrant {
        Order storage order = orders[orderId];
        require(!order.sold, "Already sold");
        require(previewSell(order.spxBought) * 1000 >= order.ethSpent * profitThresholdBps, "Profit threshold not met");
        require(IERC20(SPX_TOKEN).balanceOf(address(this)) >= order.spxBought, "Not enough SPX in contract");

        IERC20(SPX_TOKEN).approve(address(uniswapRouter), order.spxBought);

        // Calculate minimum ETH out with slippage protection
        uint256 expectedEth = previewSell(order.spxBought);
        uint256 minEthOut = expectedEth.mul(10000 - maxSlippageBps).div(10000);

        address[] memory path = new address[](2);
        path[0] = SPX_TOKEN;
        path[1] = uniswapRouter.WETH();

        uniswapRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            order.spxBought,
            minEthOut, // Slippage protection
            path,
            owner(),
            block.timestamp
        );

        order.sold = true;
        payable(msg.sender).transfer(txReward);
    }

    function previewSell(uint256 amountIn) public view returns (uint256 ethExpected) {
        address[] memory path = new address[](2);
        path[0] = SPX_TOKEN;
        path[1] = uniswapRouter.WETH();

        uint[] memory amounts = uniswapRouter.getAmountsOut(amountIn, path);
        ethExpected = amounts[1];
    }

    function withdrawETH(uint256 amount) external onlyOwner {
    require(amount <= address(this).balance, "Insufficient ETH balance");
    payable(owner()).transfer(amount);
    }

    function withdrawAllTaxETH() external onlyOwner {
    uint256 balance = address(this).balance;
    require(balance > 0, "No ETH to withdraw");
    payable(owner()).transfer(balance);
    }

    function stats() public view returns(uint256[] memory) {
        uint256[] memory data = new uint256[](3);
        data[0] = IERC20(address(this)).balanceOf(DEAD_ADDRESS);
        data[1] = address(this).balance;
        data[2] = IERC20(SPX_TOKEN).balanceOf(address(this));
        return data;
    }
}