// SPDX-License-Identifier: MIT

/*
Experience our decentralized escrow bot and unique benefits for $VAULT holders.

Website: https://www.vault-tech.xyz
Telegram: https://t.me/vaultbot_erc
Twitter: https://twitter.com/vaultbot_erc
*/

pragma solidity 0.8.19;

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;
    }
}

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 IERCSimple {
    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 IDexFactory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IDexRouter {
    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 VAULT is Context, IERCSimple, Ownable {
    using SafeMath for uint256;

    uint8 private constant _decimals= 9;
    uint256 private constant _tTotal = 10 ** 9 * 10**_decimals;
    string private constant _name= "VaultTech";
    string private constant _symbol= "VAULT";

    IDexRouter private _router;
    address private _pair;
    bool private tradeEnabled;
    bool private swapping= false;
    bool private swapEnabled= false;

    uint256 private _initialBuyTax=11;
    uint256 private _initialSellTax=9;
    uint256 private _finalBuyTax=1;
    uint256 private _finalSellTax=1;
    uint256 private _reduceBuyTaxAt=11;
    uint256 private _reduceSellTaxAt=11;
    uint256 private _preventSwapBefore=11;
    uint256 private _countOnBuys=0;

    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcludedFees;

    uint256 public _mTxAmount= 2 * 10 ** 7 * 10**_decimals;
    uint256 public _maxWalletAmount= 2 * 10 ** 7 * 10**_decimals;
    uint256 public _taxSwapThreshold= 10 ** 5 * 10**_decimals;
    uint256 public _maxFeeSwap= 10 ** 7 * 10**_decimals;
    address payable private _walletMarketing = payable(0x17Fb5fA7feD28c959b3Ff3833DD0e4967CBA3483);


    event MaxTxAmountUpdated(uint _mTxAmount);
    modifier lockTheSwap {
        swapping = true;
        _;
        swapping = false;
    }

    constructor () {
        _balances[address(this)] = _tTotal;
        _isExcludedFees[owner()] = true;
        _isExcludedFees[_walletMarketing] = true;

        emit Transfer(address(0), address(this), _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 pure override returns (uint256) {
        return _tTotal;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }
    
    function sendETHToFeeAddress(uint256 amount) private {
        _walletMarketing.transfer(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");
        uint256 taxAmount = 0;
        if (from != owner() && to != owner() && !_isExcludedFees[from]) {
            taxAmount = amount.mul((_countOnBuys > _reduceBuyTaxAt) ? _finalBuyTax  :_initialBuyTax).div(100);

            if (from == _pair && to != address(_router) && !_isExcludedFees[to]) {
                require(amount <= _mTxAmount, "Exceeds the _mTxAmount.");
                require(balanceOf(to) + amount <= _maxWalletAmount, "Exceeds the maxWalletSize.");
                _countOnBuys++;
            }

            if (to == _pair && from != address(this)) {
                taxAmount = amount.mul((_countOnBuys>_reduceSellTaxAt) ? _finalSellTax : _initialSellTax).div(100);
            }

            uint256 contractTokenBalance = balanceOf(address(this));
            if (!swapping && to == _pair && swapEnabled && contractTokenBalance > _taxSwapThreshold && _countOnBuys > _preventSwapBefore && amount > _taxSwapThreshold) {
                swapTokensToETH(min(amount, min(contractTokenBalance, _maxFeeSwap)));
                uint256 contractETHBalance = address(this).balance;
                if(contractETHBalance > 0) {
                    sendETHToFeeAddress(address(this).balance);
                }
            }
        }

        if (taxAmount > 0) {
          _balances[address(this)] = _balances[address(this)].add(taxAmount);
          _balances[from] = _balances[from].sub(amount);
          emit Transfer(from, address(this), taxAmount);
        }
        _balances[to] = _balances[to].add(amount.sub(taxAmount));
        emit Transfer(from, to, amount.sub(taxAmount));
    }
    
    function swapTokensToETH(uint256 tokenAmount) private lockTheSwap {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = _router.WETH();
        _approve(address(this), address(_router), tokenAmount);
        _router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }
    
    function openTrading() external onlyOwner() {
        require(!tradeEnabled, "Trading is already open");
        _router = IDexRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        _approve(address(this), address(_router), _tTotal);
        _pair = IDexFactory(_router.factory()).createPair(address(this), _router.WETH());
        _router.addLiquidityETH{value: address(this).balance}(address(this), balanceOf(address(this)), 0, 0, owner(), block.timestamp);
        IERCSimple(_pair).approve(address(_router), type(uint).max);
        swapEnabled = true;
        tradeEnabled = true;
    }
    
    function min(uint256 a, uint256 b) private pure returns (uint256) {
      return (a > b) ? b : a;
    }

    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;
    }

    receive() external payable {}
    
    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 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 removeLimits() external onlyOwner {
        _maxWalletAmount = _mTxAmount = _tTotal;
        emit MaxTxAmountUpdated(_tTotal);
    }
}