//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 ItProtocol is IERC20, Auth {
    using SafeMath for uint256;

    address public WETH;
    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;

    string constant _name = "It Protocol";
    string constant _symbol = "IT";
    uint8 constant _decimals = 9;

    uint256 _totalSupply = 1 * 10 ** 5 * (10 ** _decimals);
    uint256 public _maxTxAmount = _totalSupply  / 100; // 1%
    uint256 public _maxWalletToken = _totalSupply / 100; // 2%

    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) _allowances;

    mapping (address => bool) isFeeExempt;
    mapping (address => bool) isLimitExempt;

    bool tradingEnabled = false;

    uint256 marketingFee = 20;
    uint256 totalFee = 20;

    uint256 feeDenominator = 1000;
    uint256 feeAmount;

    address public marketingFeeReceiver;

    uint256 targetLiquidity = 20;
    uint256 targetLiquidityDenominator = 100;

    IDEXRouter public router;
    address public pair;

    // Cooldown & timer functionality

    bool public swapEnabled = true;
    uint256 public swapThreshold = _totalSupply * 10 / 10000; // 0.01% of supply
    bool inSwap;
    modifier swapping() { inSwap = true; _; inSwap = false; }

    constructor () Auth(msg.sender) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D );
        // router = IDEXRouter(0xD99D1c33F9fC3444f8101754aBC46c52416550D1 );
        
        
        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;
        
        isFeeExempt[msg.sender] = true;
        isFeeExempt[address(this)] = true;
        
        marketingFeeReceiver = msg.sender;
        
        _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 removeLimits() external onlyOwner{
        _maxWalletToken = _totalSupply;
        _maxTxAmount = _totalSupply;
    }

    function _transferFrom(address sender, address recipient, uint256 amount) internal returns (bool) {
        if(inSwap){ return _basicTransfer(sender, recipient, amount); }
        require(tradingEnabled || isLimitExempt[sender], "Trading is not enabled.");
        
        // 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 = shouldTakeFee(sender) ? takeFee(sender, amount) : amount;
        _balances[recipient] = _balances[recipient].add(amountReceived);

        emit Transfer(sender, recipient, amountReceived);
        return true;
    }

    function enableTrading() public onlyOwner{
        tradingEnabled = 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, address recipient) internal view {
        require(amount <= _maxTxAmount || isLimitExempt[sender] || isLimitExempt[recipient] , "TX Limit Exceeded");
    }

    function shouldTakeFee(address sender) internal view returns (bool) {
        return !isFeeExempt[sender];
    }

    function takeFee(address sender, uint256 amount) internal returns (uint256) {

        feeAmount = amount.mul(totalFee).div(feeDenominator);
        
        _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 swapBack() internal swapping {

        uint256 amountToSwap = swapThreshold;

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = WETH;

        uint256 balanceBefore = address(this).balance;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amountETH = address(this).balance.sub(balanceBefore);
        uint256 amountETHMarketing = amountETH;

        payable(marketingFeeReceiver).call{value: amountETHMarketing, gas:30000};
        
    }

    function setIsLimitExempt(address holder, bool exempt) external authorized {
        isLimitExempt[holder] = exempt;
    }

    function setIsFeeExempt(address holder, bool exempt) external authorized {
        isFeeExempt[holder] = exempt;
    }


    function setFeeReceivers( address _marketingFeeReceiver) external authorized {
        marketingFeeReceiver = _marketingFeeReceiver;
    }

    function setSwapBackSettings(bool _enabled, uint256 _amount) external authorized {
        swapEnabled = _enabled;
        swapThreshold = _amount;
    }

    function getStuckBalance() external authorized {
        uint256 contractETHBalance = address(this).balance;
        payable(marketingFeeReceiver).transfer(contractETHBalance);
    }
    
    function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply.sub(balanceOf(DEAD)).sub(balanceOf(ZERO));
    }

}