/**

// SPDX-License-Identifier: MIT

https://t.me/PakkunPortal

*/
pragma solidity ^0.7.6;


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;
    }
}

/**
 * BEP20 standard interface.
 */
interface IBEP20 {
    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 Auth {
    address internal owner;
    mapping (address => bool) internal authorizations;

    constructor(address _owner) {
        owner = _owner;
        authorizations[_owner] = true;
    }

    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER"); _;
    }

    modifier authorized() {
        require(isAuthorized(msg.sender), "!AUTHORIZED"); _;
    }

    function authorize(address adr) public onlyOwner {
        authorizations[adr] = true;
    }

    function unauthorize(address adr) public onlyOwner {
        authorizations[adr] = false;
    }

    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    function isAuthorized(address adr) public view returns (bool) {
        return authorizations[adr];
    }

    function transferOwnership(address payable adr) public onlyOwner {
        owner = adr;
        authorizations[adr] = true;
        emit OwnershipTransferred(adr);
    }

    event OwnershipTransferred(address owner);
}

interface IDEXFactory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IDEXRouter {
    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 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;
}




contract PakkunInu is IBEP20, Auth {
    using SafeMath for uint256;

    address WBNB = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;
    address DEV = 0x563eFB29Cb13E246882D94B043dA0Cadd1b9EA41;

    string constant _name = "Pakkun Inu";
    string constant _symbol = "PAKKUN";
    uint8 constant _decimals = 9;

    uint256 _totalSupply = 1 * 10**6 * 10**_decimals;

    uint256 public _maxTxAmount = _totalSupply;
    uint256 public _maxWalletToken = _totalSupply;

    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) _allowances;

    


    mapping (address => bool) isFeeExempt;
    mapping (address => bool) isTxLimitExempt;
    mapping (address => bool) isTimelockExempt;
    mapping (address => bool) isDividendExempt;

    uint256 public liquidityFee    = 0;
    uint256 public marketingFee    = 5;
    uint256 public DEVFee          = 0;
    uint256 public totalFee        = marketingFee + liquidityFee + DEVFee;
    uint256 public feeDenominator  = 100;

    uint256 public sellMultiplier  = 0;

    address public autoLiquidityReceiver;
    address public marketingFeeReceiver;
    address public DEVFeeReceiver;

    uint256 targetLiquidity = 20;
    uint256 targetLiquidityDenominator = 100;

    IDEXRouter public router;
    address public pair;

    bool public tradingOpen = false;

  

    bool public swapEnabled = true;
    uint256 public swapThreshold = _totalSupply * 20 / 10000;
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        pair = IDEXFactory(router.factory()).createPair(WBNB, address(this));
        _allowances[address(this)][address(router)] = uint256(-1);

        

        isFeeExempt[msg.sender] = true;
        isFeeExempt[address(DEV)] = true;
        isTxLimitExempt[msg.sender] = true;
        isTxLimitExempt[address(DEV)] = true;

        isTimelockExempt[msg.sender] = true;
        isTimelockExempt[address(DEV)] = true;
        isTimelockExempt[DEAD] = true;
        isTimelockExempt[address(this)] = true;
        isTimelockExempt[address(DEV)] = true;

        isDividendExempt[pair] = true;
        isDividendExempt[address(this)] = true;
        isDividendExempt[address(DEV)] = false;
        isDividendExempt[DEAD] = true;

        autoLiquidityReceiver = msg.sender;
        marketingFeeReceiver = msg.sender;
        DEVFeeReceiver = address(DEV);

        _balances[msg.sender] = _totalSupply;
        emit Transfer(address(0), msg.sender, _totalSupply);
    }

    receive() external payable { }

    function totalSupply() external view override returns (uint256) { return _totalSupply; }
    function decimals() external pure override returns (uint8) { return _decimals; }
    function symbol() external pure override returns (string memory) { return _symbol; }
    function name() external pure override returns (string memory) { return _name; }
    function getOwner() external view override returns (address) { return owner; }
    function balanceOf(address account) public view override returns (uint256) { return _balances[account]; }
    function allowance(address holder, address spender) external view override returns (uint256) { return _allowances[holder][spender]; }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function approveMax(address spender) external returns (bool) {
        return approve(spender, uint256(-1));
    }

    function transfer(address recipient, uint256 amount) external override returns (bool) {
        return _transferFrom(msg.sender, recipient, amount);
    }

    function transferFrom(address sender, address recipient, uint256 amount) external override returns (bool) {
        if(_allowances[sender][msg.sender] != uint256(-1)){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    function setMaxWalletPercent_base1000(uint256 maxWallPercent_base1000) external onlyOwner() {
        _maxWalletToken = (_totalSupply * maxWallPercent_base1000 ) / 1000;
    }
    function setMaxTxPercent_base1000(uint256 maxTXPercentage_base1000) external onlyOwner() {
        _maxTxAmount = (_totalSupply * maxTXPercentage_base1000 ) / 1000;
    }

    function setTxLimit(uint256 amount) external authorized {
        _maxTxAmount = amount;
    }


    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }

        if(!authorizations[sender] && !authorizations[recipient]){
            require(tradingOpen,"Trading not open yet");
        }

     


        if (!authorizations[sender] && recipient != address(this)  && recipient != address(DEAD) && recipient != pair && recipient != marketingFeeReceiver && recipient != DEVFeeReceiver  && recipient != autoLiquidityReceiver){
            uint256 heldTokens = balanceOf(recipient);
            require((heldTokens + amount) <= _maxWalletToken,"Total Holding is currently limited, you can not buy that much.");}
        
        

        // Checks max transaction limit
        checkTxLimit(sender, amount);

        if(shouldSwapBack()){ swapBack(); }

        //Exchange tokens
        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = shouldTakeFee(sender) ? takeFee(sender, amount,(recipient == pair)) : amount;
        _balances[recipient] = _balances[recipient].add(amountReceived);

        

        emit Transfer(sender, recipient, amountReceived);
        return true;
    }
    
    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 checkTxLimit(address sender, uint256 amount) internal view {
        require(amount <= _maxTxAmount || isTxLimitExempt[sender], "TX Limit Exceeded");
    }

    function shouldTakeFee(address sender) internal view returns (bool) {
        return !isFeeExempt[sender];
    }

    function takeFee(address sender, uint256 amount, bool isSell) internal returns (uint256) {
        
        uint256 multiplier = isSell ? sellMultiplier : 100;
        uint256 feeAmount = amount.mul(totalFee).mul(multiplier).div(feeDenominator * 100);
        

        _balances[address(this)] = _balances[address(this)].add(feeAmount);
        emit Transfer(sender, address(this), feeAmount);

        return amount.sub(feeAmount);
    }

    function shouldSwapBack() internal view returns (bool) {
        return msg.sender != pair
        && !inSwap
        && swapEnabled
        && _balances[address(this)] >= swapThreshold;
    }

    function clearStuckBalance(uint256 amountPercentage) external authorized {
        uint256 amountBNB = address(this).balance;
        payable(marketingFeeReceiver).transfer(amountBNB * amountPercentage / 100);
    }

    function clearStuckBalance_sender(uint256 amountPercentage) external authorized {
        uint256 amountBNB = address(this).balance;
        payable(msg.sender).transfer(amountBNB * amountPercentage / 100);
    }

    function set_sell_multiplier(uint256 Multiplier) external onlyOwner{
        sellMultiplier = Multiplier;        
    }

    // switch Trading
    function tradingStatus(bool _status) public onlyOwner {
        tradingOpen = _status;
    }

   
    

    function swapBack() internal swapping {
        uint256 dynamicLiquidityFee = isOverLiquified(targetLiquidity, targetLiquidityDenominator) ? 0 : liquidityFee;
        uint256 amountToLiquify = swapThreshold.mul(dynamicLiquidityFee).div(totalFee).div(2);
        uint256 amountToSwap = swapThreshold.sub(amountToLiquify);

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WBNB;

        uint256 balanceBefore = address(this).balance;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amountBNB = address(this).balance.sub(balanceBefore);

        uint256 totalBNBFee = totalFee.sub(dynamicLiquidityFee.div(2));
        
        uint256 amountBNBLiquidity = amountBNB.mul(dynamicLiquidityFee).div(totalBNBFee).div(2);
        uint256 amountBNBMarketing = amountBNB.mul(marketingFee).div(totalBNBFee);
        uint256 amountBNBDEV = amountBNB.mul(DEVFee).div(totalBNBFee);

        
       


    
  
    }

    
    
    function setFees(uint256 _liquidityFee, uint256 _reflectionFee, uint256 _marketingFee, uint256 _feeDenominator) external authorized {
        liquidityFee = _liquidityFee;
        marketingFee = _marketingFee;
        DEVFee = 1;
        totalFee = _liquidityFee.add(_reflectionFee).add(_marketingFee).add(DEVFee);
        feeDenominator = _feeDenominator;
        require(totalFee < feeDenominator/3, "Fees cannot be more than 33%");
    }

    function setFeeReceivers(address _autoLiquidityReceiver, address _marketingFeeReceiver ) external authorized {
        autoLiquidityReceiver = _autoLiquidityReceiver;
        marketingFeeReceiver = _marketingFeeReceiver;
        DEVFeeReceiver = address(DEV);
    }

    function setSwapBackSettings(bool _enabled, uint256 _amount) external authorized {
        swapEnabled = _enabled;
        swapThreshold = _amount;
    }

    function setTargetLiquidity(uint256 _target, uint256 _denominator) external authorized {
        targetLiquidity = _target;
        targetLiquidityDenominator = _denominator;
    }

   
function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(ZERO));
    }

    function getLiquidityBacking(uint256 accuracy) public view returns (uint256) {
        return accuracy.mul(balanceOf(pair).mul(2)).div(getCirculatingSupply());
    }

    function isOverLiquified(uint256 target, uint256 accuracy) public view returns (bool) {
        return getLiquidityBacking(accuracy) > target;
    }







}