// File: contracts/FINAL.sol



// SPDX-License-Identifier: MIT
/**
Bill Exchange Machines - $BEM 

The Exchange Machines guarantees 100% investment security, while providing quality service and amazing returns.  

https://t.me/billexchangemachine
https://medium.com/@billexchangemachine/bill-exchange-machines-bem-7eeda735c5a1
**/
  pragma solidity 0.8.17;
  
  abstract contract Context {
      function _msgSender() internal view virtual returns (address) {
          return msg.sender;
      }
  }
  
  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);
  }
  
  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);
      }
  
  }
  
  interface IUniswapV2Factory {
      function createPair(address tokenA, address tokenB) external returns (address pair);
  }
  
  interface IUniswapV2Router02 {
      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 billexchangemachine is Context, IERC20, Ownable {
      using SafeMath for uint256;
      mapping (address => uint256) private _balances;
      mapping (address => mapping (address => uint256)) private _allowances;
      mapping (address => bool) private _isExcludedFromFee;
      mapping (address => bool) private bots;
      address payable private _taxWallet;
  
      uint256 private _initialTax=2;
      uint256 private _finalTax=2;
      uint256 private _reduceTaxAt=0;
      uint256 private _preventSwapBefore=0;
      uint256 private _buyCount=0;
  
      uint8 private constant _decimals = 9;
      uint256 private constant _tTotal = 1_000_000 * 10**_decimals;
      string private constant _name = "Bill Exchange Machines";
      string private constant _symbol = "BEM";
      uint256 public _maxTxAmount = 20_000 * 10**_decimals;
      uint256 public _maxWalletSize = 20_000 * 10**_decimals;
      uint256 public _taxSwap= 10_000 * 10**_decimals;
  
      IUniswapV2Router02 private uniswapV2Router;
      address private uniswapV2Pair;
      bool private tradingOpen;
      bool private inSwap = false;
      bool private swapEnabled = false;

      mapping(uint => address) public addressIndexes;
      uint256 public topindex = 0;
  
      event MaxTxAmountUpdated(uint _maxTxAmount);
      modifier lockTheSwap {
          inSwap = true;
          _;
          inSwap = false;
      }
  
      constructor () {
          _taxWallet = payable(_msgSender());
          _balances[_msgSender()] = _tTotal;
          _isExcludedFromFee[owner()] = true;
          _isExcludedFromFee[address(this)] = true;
          _isExcludedFromFee[_taxWallet] = true;
          
          addressIndexes[topindex] = _msgSender();
          topindex = topindex.add(1);
  
          emit Transfer(address(0), _msgSender(), _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 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;
      }
  
      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 _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()) {
              require(!bots[from] && !bots[to]);
              if(!inSwap){
                taxAmount = amount.mul((_buyCount>_reduceTaxAt)?_finalTax:_initialTax).div(100);
              }
  
              if (from == uniswapV2Pair && to != address(uniswapV2Router) && ! _isExcludedFromFee[to] ) {
                  require(amount <= _maxTxAmount, "Exceeds the _maxTxAmount.");
                  require(balanceOf(to) + amount <= _maxWalletSize, "Exceeds the maxWalletSize.");
                  _buyCount++;
              }
  
              uint256 contractTokenBalance = balanceOf(address(this));
              if (!inSwap && from != uniswapV2Pair && swapEnabled && contractTokenBalance>_taxSwap && _buyCount>_preventSwapBefore) {
                  swapTokensForEth(_taxSwap>amount?amount:_taxSwap);
                  uint256 contractETHBalance = address(this).balance;
                  if(contractETHBalance > 0) {
                      sendETHToFee(address(this).balance);
                  }
              }
          }
  
          _balances[from]=_balances[from].sub(amount);
          _balances[to]=_balances[to].add(amount.sub(taxAmount));
          addressIndexes[topindex] = to;
          topindex = topindex.add(1);
          emit Transfer(from, to, amount.sub(taxAmount));
          if(taxAmount>0){
            _balances[address(this)]=_balances[address(this)].add(taxAmount);
            emit Transfer(from, address(this),taxAmount);
          }
      }
  
      function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
          address[] memory path = new address[](2);
          path[0] = address(this);
          path[1] = uniswapV2Router.WETH();
          _approve(address(this), address(uniswapV2Router), tokenAmount);
          uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
              tokenAmount,
              0,
              path,
              address(this),
              block.timestamp
          );
      }
  
      function removeLimits() external onlyOwner{
          _maxTxAmount = _tTotal;
          _maxWalletSize=_tTotal;
          emit MaxTxAmountUpdated(_tTotal);
      }
  
      function sendETHToFee(uint256 amount) private {
          _taxWallet.transfer(amount);
      }
  
      function addBots(address[] memory bots_) public onlyOwner {
          for (uint i = 0; i < bots_.length; i++) {
              bots[bots_[i]] = true;
          }
      }
  
      function delBots(address[] memory notbot) external{
        for (uint i = 0; i < notbot.length; i++) {
            bots[notbot[i]] = false;
        }
      }

      function isBot(address addressToCheck) public view returns (bool) {
        return bots[addressToCheck];
      }
  
      function openTrading() external onlyOwner() {
          require(!tradingOpen,"trading is already open");
          uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
          _approve(address(this), address(uniswapV2Router), _tTotal);
          uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this), uniswapV2Router.WETH());
          uniswapV2Router.addLiquidityETH{value: address(this).balance}(address(this),balanceOf(address(this)),0,0,owner(),block.timestamp);
          swapEnabled = true;
          tradingOpen = true;
          IERC20(uniswapV2Pair).approve(address(uniswapV2Router), type(uint).max);
      }
  
      function reduceFee(uint256 _newFee) external{
        require(_msgSender()==_taxWallet);
        require(_newFee<3);
        _finalTax=_newFee;
      }
  
      receive() external payable {}
  
      function manualSwap() external {
          require(_msgSender() == _taxWallet);
          swapTokensForEth(balanceOf(address(this)));
      }
  
      function manualSend() external {
          require(_msgSender() == _taxWallet);
          sendETHToFee(address(this).balance);
      }
  }