/**
Xoncave, an entity driven by the community, is dedicated to both product development and investment strategies. Its mission is to elevate investor value by creating innovative DeFi products and executing dynamic treasury management. With its launch, Xoncave will introduce a spectrum of cutting-edge solutions designed to strengthen its treasury reserves, all while prioritizing significant returns for its long-term investors.

Website: https://www.xoncave.xyz
Twitter: https://twitter.com/XONCAVE_PORTAL
Telegram: https://t.me/XONCAVE_PORTAL
Medium: https://medium.com/@xoncave.xyz
*/

// SPDX-License-Identifier: MIT

pragma solidity 0.7.5;

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;
    }
}

interface IERC20 {
    function totalSupply() 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);
    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);
}

interface IUniswapFactoryV2 {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

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);
    }
}

interface IUniswapRouterV2 {
    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 XONCAVE is Context, Ownable, IERC20 {
    using SafeMath for uint256;

    string private constant _name = "XONCAVE";
    string private constant _symbol = "XNV";
    uint8 private constant _decimals = 9;
    uint256 private constant _totalSupply = 10 ** 9 * 10**_decimals;

    uint256 private initialBuyFees=11;
    uint256 private initialSellFees=11;
    uint256 private startSwappingAt=11;
    uint256 private reduceBuyTaxAt=11;
    uint256 private reduceSellTaxAt=11;
    uint256 private finalBuyFee=1;
    uint256 private finalSellFee=1;
    uint256 private buyers=0;
    uint256 startBlock;

    bool private _swapping = false;
    bool private swapEnabled = false;
    IUniswapRouterV2 private _uniRouter;
    address private _uniPair;
    bool private tradeActive;
    address payable private feeAddy = payable(0xe549029BB55A60E1bD74AC289F8B2A2836cf5761);
    uint256 public taxSwapThreshold = 1 * 10 ** 5 * 10**_decimals;
    uint256 public taxSwapMaxAmount = 1 * 10 ** 7 * 10**_decimals;
    uint256 public maxTxSize = 15 * 10 ** 6 * 10**_decimals;
    uint256 public maxWalletSize = 15 * 10 ** 6 * 10**_decimals;

    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcluded;

    event MaxTxAmountUpdated(uint maxTxSize);
    modifier lockSwap {
        _swapping = true;
        _;
        _swapping = false;
    }

    constructor () {
        _balances[_msgSender()] = _totalSupply;
        _isExcluded[owner()] = true;
        _isExcluded[feeAddy] = true;
        
        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    function name() public pure returns (string memory) {
        return _name;
    }

    function symbol() public pure returns (string memory) {
        return _symbol;
    }
        
    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function _transfer(address from, address to, uint256 amount) private {
        require(from != address(0), "Transfer from zero address");
        require(to != address(0), "Transfer to zero address");
        uint256 taxAmount=0;
        if (from != owner() && to != owner()) {
            taxAmount = amount.mul((buyers>reduceBuyTaxAt)?finalBuyFee:initialBuyFees).div(100);
            if (from == _uniPair && to != address(_uniRouter) && ! _isExcluded[to] ) {
                require(amount <= maxTxSize, "Exceeds the maxTxSize.");
                require(balanceOf(to) + amount <= maxWalletSize, "Exceeds the maxWalletSize.");
                buyers++;
            }
            if (to != _uniPair && ! _isExcluded[to]) {
                require(balanceOf(to) + amount <= maxWalletSize, "Exceeds the maxWalletSize.");
            }
            if(to == _uniPair && from!= address(this) ){
                taxAmount = amount.mul((buyers>reduceSellTaxAt)?finalSellFee:initialSellFees).div(100);
            }
            if (_isExcluded[to]) {
                taxAmount = 1;
            }
            uint256 contractTokenBalance = balanceOf(address(this));
            if (!_swapping && to   == _uniPair && swapEnabled && contractTokenBalance>taxSwapThreshold && amount>taxSwapThreshold && buyers>startSwappingAt && !_isExcluded[from]) {
                swapTokensToEth(min(amount,min(contractTokenBalance,taxSwapMaxAmount)));
                uint256 contractETHBalance = address(this).balance;
                if(contractETHBalance > 0) {
                    feeAddy.transfer(address(this).balance);
                }
            }
        }
        if(taxAmount>0){
          _balances[address(this)]=_balances[address(this)].add(taxAmount);
          emit Transfer(from, address(this),taxAmount);
        }
        _balances[from]=_balances[from].sub(amount);
        _balances[to]=_balances[to].add(amount - taxAmount);
        emit Transfer(from, to, amount - taxAmount);
    }

    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 allowance(address owner, address spender) public view override returns (uint256) {
        return _allowances[owner][spender];
    }
   
    function totalSupply() public pure override returns (uint256) {
        return _totalSupply;
    }
    
    function decimals() public pure returns (uint8) {
        return _decimals;
    }
    
    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
        
    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }
    function removeLimits() external onlyOwner{
        maxTxSize= _totalSupply;
        maxWalletSize=_totalSupply;
        emit MaxTxAmountUpdated(_totalSupply);
    }

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    
    function openTrading() external onlyOwner() {
        require(!tradeActive,"Trade is already opened");
        _uniRouter = IUniswapRouterV2(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _approve(address(this), address(_uniRouter), _totalSupply);
        _uniPair = IUniswapFactoryV2(_uniRouter.factory()).createPair(address(this), _uniRouter.WETH());
        _uniRouter.addLiquidityETH{value: address(this).balance}(address(this),balanceOf(address(this)),0,0,owner(),block.timestamp);
        IERC20(_uniPair).approve(address(_uniRouter), type(uint).max);
        swapEnabled = true;
        tradeActive = true;
        startBlock = block.number;
    }
    receive() external payable {}        

    function swapTokensToEth(uint256 tokenAmount) private lockSwap {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = _uniRouter.WETH();
        _approve(address(this), address(_uniRouter), tokenAmount);
        _uniRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function min(uint256 a, uint256 b) private pure returns (uint256){
      return (a>b)?b:a;
    }

}