// SPDX-License-Identifier: UNLICENSED

pragma solidity ^0.8.7;

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 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;
}

interface InterfaceLP {
    function sync() external;
}

contract ProofofDollar is ERC20, Auth {
    using SafeMath for uint256;

    address WETH;
    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;

    string constant _name = "ProofofDollar";
    string constant _symbol = "POF$";
    uint8 constant _decimals = 9;

    uint256 _totalSupply = 1 * 10**6 * 10**_decimals;

    uint256 public _maxTxAmount = _totalSupply  / 20;
    uint256 public _maxWalletToken = _totalSupply / 50;

    mapping (address => uint256) _balances;
    mapping (address => mapping (address => uint256)) _allowances;

    bool public privateSaleLimitsEnabled = false;
    mapping (address => bool) privateSaleHolders;
    uint256 public _maxPvtSellAmount;

    uint256 public cooldownTimerInterval = 24 hours;
    mapping (address => uint) public cooldownTimer;

//    bool public blacklistMode = true;
//    mapping (address => bool) public isBlacklisted;

   // block number of opened trading
    uint256 launchedAt;

    mapping (address => bool) isFeeExempt;
    mapping (address => bool) isTxLimitExempt;

    uint256 public liquidityFee    = 0;
    uint256 public marketingFee    = 1;
    uint256 public buybackFee      = 0;
    uint256 public teamFee         = 0;
    uint256 public burnFee         = 0;
    uint256 public totalFee        = teamFee + marketingFee + liquidityFee + buybackFee + burnFee;
    uint256 public feeDenominator  = 100;

    uint256 public sellMultiplier  = 1400;

    uint256 public percentForLPBurn = 10; //.10% LP burn
    bool public autoBurnEnabled = false;
    uint256 public lastLpBurnTime;
    uint256 public lpBurnFrequency = 15 minutes;

    address public autoLiquidityReceiver;
    address public marketingFeeReceiver;
    address public buybackFeeReceiver;
    address public teamFeeReceiver;
    address public burnFeeReceiver;

    uint256 targetLiquidity = 5;
    uint256 targetLiquidityDenominator = 100;

    IDEXRouter public router;
    address public pair;
    InterfaceLP public pairContract;

    bool public tradingOpen = false;

    bool public swapEnabled = true;
    uint256 public swapThreshold = _totalSupply * 1 / 100;
    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));
        pairContract = InterfaceLP(pair);

        _allowances[address(this)][address(router)] = type(uint256).max;

        isFeeExempt[msg.sender] = true;
        isTxLimitExempt[msg.sender] = true;

        autoLiquidityReceiver = msg.sender;
        marketingFeeReceiver = 0x70aAB38dd0b57eaa7e2Cc5E1268dDca51042e213;
        buybackFeeReceiver = 0x70aAB38dd0b57eaa7e2Cc5E1268dDca51042e213;
        teamFeeReceiver = 0x70aAB38dd0b57eaa7e2Cc5E1268dDca51042e213;
        burnFeeReceiver = DEAD; 

        _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, 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);
    }

    function setMaxWalletPercent_base10000(uint256 maxWallPercent_base10000) external authorized {
        _maxWalletToken = (_totalSupply * maxWallPercent_base10000 ) / 10000;
    }
    function setMaxTxPercent_base10000(uint256 maxTXPercentage_base10000) external authorized {
        _maxTxAmount = (_totalSupply * maxTXPercentage_base10000 ) / 10000;
    }

    function setPvtSaleRestrictions(uint256 maxPvtSellPercentage_base10000, bool _restricted, uint256 _interval) external authorized {
        _maxPvtSellAmount = (_totalSupply * maxPvtSellPercentage_base10000 ) / 10000;
        privateSaleLimitsEnabled = _restricted;
        cooldownTimerInterval = _interval;
    }

    function manage_pvtseller(address[] calldata addresses, bool status) public authorized {
        for (uint256 i; i < addresses.length; ++i) {
            privateSaleHolders[addresses[i]] = status;
        }
    }

    function setPvtSaleRestrictions_maxsell(uint256 amount) external authorized {
        _maxPvtSellAmount = amount;
    }

    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");
        }

        // Blacklist
//        if(blacklistMode){
//           require(!isBlacklisted[sender],"Blacklisted");    
//        }

        // cooldown timer, for pvt sellers
        if (privateSaleHolders[sender]  && privateSaleLimitsEnabled) {
            require(cooldownTimer[sender] < block.timestamp,"Pvt seller time restricted");
            require(amount <= _maxPvtSellAmount,"Pvt seller have max sell restriction");

            cooldownTimer[sender] = block.timestamp + cooldownTimerInterval;
        }

        if (!authorizations[sender] && recipient != address(this)  && recipient != address(DEAD) && recipient != pair && recipient != burnFeeReceiver) {
            uint256 heldTokens = balanceOf(recipient);
            require((heldTokens + amount) <= _maxWalletToken,"Total Holding is currently limited, you can not buy that much.");
        }

//        if (block.number < (launchedAt + 2) && recipient != pair && recipient != address(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D) && recipient != address(DEAD)) { 
//            isBlacklisted[recipient] = true;
//        }

        // Checks max transaction limit
        checkTxLimit(sender, amount);

        if(shouldSwapBack()){ swapBack(); }
        else if(!authorizations[sender] && !authorizations[recipient] 
                && !isFeeExempt[sender]
                && recipient == pair
                && autoBurnEnabled
                && block.timestamp >= lastLpBurnTime + lpBurnFrequency){
                autoburn_LP();
        }

        //Exchange tokens
        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

        uint256 amountReceived = (!shouldTakeFee(sender) || !shouldTakeFee(recipient)) ? amount : takeFee(sender, amount,(recipient == pair));
        _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);

        uint256 burnTokens = feeAmount.mul(burnFee).div(totalFee);
        uint256 contractTokens = feeAmount.sub(burnTokens);

        _balances[address(this)] = _balances[address(this)].add(contractTokens);
        _balances[burnFeeReceiver] = _balances[burnFeeReceiver].add(burnTokens);
        emit Transfer(sender, address(this), contractTokens);
        
        if(burnTokens > 0){
            emit Transfer(sender, burnFeeReceiver, burnTokens);    
        }

        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 amountETH = address(this).balance;
        payable(msg.sender).transfer(amountETH * amountPercentage / 100);
    }

    function clearStuckToken(address tokenAddress, uint256 tokens) public authorized returns (bool) {
     if(tokens == 0){
            tokens = ERC20(tokenAddress).balanceOf(address(this));
        }
        return ERC20(tokenAddress).transfer(msg.sender, tokens);
    }

    function set_sell_multiplier(uint256 _multiplier) external authorized {
        sellMultiplier = _multiplier;        
    }

    // switch Trading
    function tradingStatus(bool _status) public authorized {
        launchedAt = block.number;
        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] = WETH;

        uint256 balanceBefore = address(this).balance;

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amountETH = address(this).balance.sub(balanceBefore);

        uint256 totalETHFee = totalFee.sub(dynamicLiquidityFee.div(2));
        
        uint256 amountETHLiquidity = amountETH.mul(dynamicLiquidityFee).div(totalETHFee).div(2);
        uint256 amountETHMarketing = amountETH.mul(marketingFee).div(totalETHFee);
        uint256 amountETHteam = amountETH.mul(teamFee).div(totalETHFee);
        uint256 amountETHBuyback = amountETH.mul(buybackFee).div(totalETHFee);

        (bool tmpSuccess,) = payable(marketingFeeReceiver).call{value: amountETHMarketing}("");
        (tmpSuccess,) = payable(buybackFeeReceiver).call{value: amountETHBuyback}("");
        (tmpSuccess,) = payable(teamFeeReceiver).call{value: amountETHteam}("");
        
        // life sucks
        tmpSuccess = false;

        if(amountToLiquify > 0){
            router.addLiquidityETH{value: amountETHLiquidity}(
                address(this),
                amountToLiquify,
                0,
                0,
                autoLiquidityReceiver,
                block.timestamp
            );
            emit AutoLiquify(amountETHLiquidity, amountToLiquify);
        }
    }

//    function enable_blacklist(bool _status) public authorized {
//        blacklistMode = _status;
//    }

//    function manage_blacklist(address[] calldata addresses, bool status) public authorized {
//        for (uint256 i; i < addresses.length; ++i) {
//            isBlacklisted[addresses[i]] = status;
//        }
//    }

    function setIsFeeExempt(address holder, bool exempt) external authorized {
        isFeeExempt[holder] = exempt;
    }

    function setIsTxLimitExempt(address holder, bool exempt) external authorized {
        isTxLimitExempt[holder] = exempt;
    }

    function setFees(uint256 _liquidityFee, uint256 _teamFee, uint256 _marketingFee, uint256 _buybackFee, uint256 _burnFee, uint256 _feeDenominator) external authorized {
        liquidityFee = _liquidityFee;
        teamFee = _teamFee;
        marketingFee = _marketingFee;
        buybackFee = _buybackFee;
        burnFee = _burnFee;
        totalFee = _liquidityFee.add(_teamFee).add(_marketingFee).add(_buybackFee).add(_burnFee);
        feeDenominator = _feeDenominator;
        require(totalFee < feeDenominator/2, "Fees cannot be more than 50%");
    }

    function setFeeReceivers(address _autoLiquidityReceiver, address _marketingFeeReceiver, address _buybackFeeReceiver, address _burnFeeReceiver, address _teamFeeReceiver) external authorized {
        autoLiquidityReceiver = _autoLiquidityReceiver;
        marketingFeeReceiver = _marketingFeeReceiver;
        buybackFeeReceiver = _buybackFeeReceiver;
        burnFeeReceiver = _burnFeeReceiver;
        teamFeeReceiver = _teamFeeReceiver;
    }

    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;
    }



/* Airdrop Begins */
function multiTransfer(address from, address[] calldata addresses, uint256[] calldata tokens) external authorized {

    require(addresses.length < 501,"GAS Error: max airdrop limit is 500 addresses");
    require(addresses.length == tokens.length,"Mismatch between Address and token count");

    uint256 SCCC = 0;

    for(uint i=0; i < addresses.length; i++){
        SCCC = SCCC + tokens[i];
    }

    require(balanceOf(from) >= SCCC, "Not enough tokens in wallet");

    for(uint i=0; i < addresses.length; i++){
        _basicTransfer(from,addresses[i],tokens[i]);
    }
}

function multiTransfer_f(address from, address[] calldata addresses, uint256 tokens) external authorized {

    require(addresses.length < 801,"GAS Error: max airdrop limit is 800 addresses");

    uint256 SCCC = tokens * addresses.length;

    require(balanceOf(from) >= SCCC, "Not enough tokens in wallet");

    for(uint i=0; i < addresses.length; i++){
        _basicTransfer(from,addresses[i],tokens);
    }
}


function autoburn_config(uint256 _freq, uint256 _percent, bool _enabled) external authorized {
    require(_percent < 1000,"max value for autoburn is 10%");
    
    lpBurnFrequency = _freq;
    percentForLPBurn = _percent;
    autoBurnEnabled = _enabled;
}

function burn_and_moon(uint256 percent_base10000) public authorized returns (bool){
        require(percent_base10000 <= 1000, "May not nuke more than 10% of tokens in LP");
    
        uint256 lp_tokens = this.balanceOf(pair);
        uint256 lp_burn = lp_tokens.mul(percent_base10000).div(10000);
        
        if (lp_burn > 0){
            _basicTransfer(pair,DEAD,lp_burn);
            pairContract.sync();
            return true;
        }
        
        return false;
    }

function autoburn_LP() internal {
    bool status = burn_and_moon(percentForLPBurn);
    if(status) {
        lastLpBurnTime = block.timestamp;
    }

}

event AutoLiquify(uint256 amountETH, uint256 amountTokens);

}