/**

https://t.me/GemCommunityPortal

*/

// SPDX-License-Identifier: MIT
pragma solidity 0.8.9;

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);
}

interface IFactoryV2 {
    event PairCreated(address indexed token0, address indexed token1, address lpPair, uint);
    function getPair(address tokenA, address tokenB) external view returns (address lpPair);
    function createPair(address tokenA, address tokenB) external returns (address lpPair);
}

interface IV2Pair {
    function factory() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function sync() external;
}

interface IRouter01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    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 swapExactETHForTokens(
        uint amountOutMin, 
        address[] calldata path, 
        address to, uint deadline
    ) external payable returns (uint[] memory amounts);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IRouter02 is IRouter01 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        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 swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
}

contract GEM is IERC20 {
    mapping (address => uint256) private _rOwned;
    mapping (address => uint256) private _tOwned;
    mapping (address => bool) lpPairs;
    uint256 private timeSinceLastPair = 0;
    mapping (address => mapping (address => uint256)) private _allowances;

    mapping (address => bool) private _liquidityHolders;
    mapping (address => bool) private _isExcludedFromFees;
    mapping (address => bool) private _isExcludedFromLimits;
    mapping (address => bool) private bots;

   
    uint256 constant private startingSupply = 100_000_000;
    string constant private _name = "Gem";
    string constant private _symbol = "GEM";
    uint8 constant private _decimals = 9;

    uint256 private _tTotal = startingSupply * 10**_decimals;

    struct Fees {
        uint16 buyFee;
        uint16 sellFee;
        uint16 transferFee;
    }

    struct Ratios {
        uint16 liquidity;
        uint16 marketing;
        uint16 development;
        uint16 burn;
        uint16 buyback;
        uint16 totalSwap;
    }

    Fees public _taxRates = Fees({
        buyFee: 1000,
        sellFee: 2000,
        transferFee: 0
    });

    Ratios public _ratios = Ratios({
        liquidity: 0,
        marketing: 0,
        development: 1000,
        burn: 0,
        buyback: 0,
        totalSwap: 1000
    });

    uint256 constant public maxBuyTaxes = 3000;
    uint256 constant public maxSellTaxes = 3000;
    uint256 constant public maxTransferTaxes = 0;
    uint256 constant public maxRoundtripTax = 6000;
    uint256 constant masterTaxDivisor = 10000;

    bool public taxesAreLocked;
    IRouter02 public dexRouter;
    address public lpPair;
    address constant public DEAD = 0x000000000000000000000000000000000000dEaD;

    struct TaxWallets {
        address payable marketing;
        address payable development;
        address payable liquidity;
        address payable buyback;
    }

    TaxWallets public _taxWallets = TaxWallets({
        marketing: payable(0x32b73F001b8d4E5164A97e706e9d7EF2De8b5Af3), 
        development: payable(0x32b73F001b8d4E5164A97e706e9d7EF2De8b5Af3),
        liquidity: payable(DEAD),
        buyback: payable(DEAD)
    });
    
    bool inSwap;
    bool public contractSwapEnabled = false;
    uint256 public swapThreshold;
    uint256 public swapAmount;
    bool public piContractSwapsEnabled;
    uint256 public piSwapPercent = 10;
    
    uint256 private _maxTxAmount = (_tTotal * 2) / 100;
    uint256 private _maxWalletSize = (_tTotal * 2) / 100;

    bool public tradingEnabled = false;
    bool public _hasLiqBeenAdded = false;

    address public buyback = address(this);

    uint256 public _totalBuyback;
    uint256 public _totalBurned;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    event ContractSwapEnabledUpdated(bool enabled);
    event AutoLiquify(uint256 amountCurrency, uint256 amountTokens);
    
    modifier inSwapFlag {
        inSwap = true;
        _;
        inSwap = false;
    }

    modifier onlyOwner() {
        require(_owner == msg.sender, "Caller =/= owner.");
        _;
    }

    constructor () payable {
        // Set the owner.
        _owner = _taxWallets.development;
        dexRouter = IRouter02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);

        _tOwned[_owner] = _tTotal;
        emit Transfer(address(0), _owner, _tTotal);

        lpPair = IFactoryV2(dexRouter.factory()).createPair(dexRouter.WETH(), address(this));
        lpPairs[lpPair] = true;

        _approve(_owner, address(dexRouter), type(uint256).max);
        _approve(address(this), address(dexRouter), type(uint256).max);

        _isExcludedFromFees[_owner] = true;
        _isExcludedFromFees[address(this)] = true;
        _isExcludedFromFees[DEAD] = true;
        _liquidityHolders[_owner] = true;
    }

    receive() external payable {}

//===============================================================================================================
//===============================================================================================================
//===============================================================================================================
    // Ownable removed as a lib and added here to allow for custom transfers and renouncements.
    // This allows for removal of ownership privileges from the owner once renounced or transferred.
    address private _owner;

    function transferOwner(address newOwner) external onlyOwner {
        require(newOwner != address(0), "Call renounceOwnership to transfer owner to the zero address.");
        require(newOwner != DEAD, "Call renounceOwnership to transfer owner to the zero address.");
        setExcludedFromFees(_owner, false);
        setExcludedFromFees(newOwner, true);
        
        if (balanceOf(_owner) > 0) {
            finalizeTransfer(_owner, newOwner, balanceOf(_owner), false, false, true);
        }
        
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
        
    }

    function renounceOwnership() external onlyOwner {
        setExcludedFromFees(_owner, false);
        address oldOwner = _owner;
        _owner = address(0);
        emit OwnershipTransferred(oldOwner, address(0));
    }

//===============================================================================================================
//===============================================================================================================
//===============================================================================================================

    function totalSupply() external view override returns (uint256) { return _tTotal; }
    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 allowance(address holder, address spender) external view override returns (uint256) { return _allowances[holder][spender]; }
    function balanceOf(address account) public view override returns (uint256) {
        return _tOwned[account];
    }

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

    function approve(address spender, uint256 amount) external override returns (bool) {
        _approve(msg.sender, spender, amount);
        return true;
    }

    function _approve(address sender, address spender, uint256 amount) internal {
        require(sender != address(0), "ERC20: Zero Address");
        require(spender != address(0), "ERC20: Zero Address");

        _allowances[sender][spender] = amount;
        emit Approval(sender, spender, 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] -= amount;
        }

        return _transfer(sender, recipient, amount);
    }

    function isExcludedFromLimits(address account) external view returns (bool) {
        return _isExcludedFromLimits[account];
    }

    function isExcludedFromFees(address account) external view returns(bool) {
        return _isExcludedFromFees[account];
    }

    function setExcludedFromLimits(address account, bool enabled) external onlyOwner {
        _isExcludedFromLimits[account] = enabled;
    }

    function setExcludedFromFees(address account, bool enabled) public onlyOwner {
        _isExcludedFromFees[account] = enabled;
    }

    function getCirculatingSupply() public view returns (uint256) {
        return (_tTotal - (balanceOf(DEAD) + balanceOf(address(0))));
    }

    function setTaxes(uint16 buyFee, uint16 sellFee, uint16 transferFee) external onlyOwner {
        require(buyFee <= maxBuyTaxes
                && sellFee <= maxSellTaxes
                && transferFee <= maxTransferTaxes,
                "Cannot exceed maximums.");
        require(buyFee + sellFee <= maxRoundtripTax, "Cannot exceed roundtrip maximum.");
        _taxRates.buyFee = buyFee;
        _taxRates.sellFee = sellFee;
        _taxRates.transferFee = transferFee;
    }

    function setRatios(uint16 liquidity, uint16 marketing, uint16 development, uint16 burn, uint16 _buyBack) external onlyOwner {
        _ratios.liquidity = liquidity;
        _ratios.marketing = marketing;
        _ratios.development = development;
        _ratios.burn = burn;
        _ratios.buyback = _buyBack;
        _ratios.totalSwap = liquidity + marketing + development + _buyBack;
        uint256 total = _taxRates.buyFee + _taxRates.sellFee;
        require(_ratios.totalSwap + _ratios.burn <= total, "Cannot exceed sum of buy and sell fees.");
    }

    function setWallets(address payable marketing, address payable development, address payable liquidity) external onlyOwner {
        _taxWallets.marketing = payable(marketing);
        _taxWallets.development = payable(development);
        _taxWallets.liquidity = payable(liquidity);
    }

    function setPurchaseDestinations(address payable _buyBack) external onlyOwner {
        _taxWallets.buyback = payable(_buyBack);
    }

    function setMaxTxPercent(uint256 percent, uint256 divisor) external onlyOwner {
        require((_tTotal * percent) / divisor >= (_tTotal * 5 / 1000), "Max Transaction amt must be above 0.5% of total supply.");
        _maxTxAmount = (_tTotal * percent) / divisor;
    }

    function setMaxWalletSize(uint256 percent, uint256 divisor) external onlyOwner {
        require((_tTotal * percent) / divisor >= (_tTotal / 100), "Max Wallet amt must be above 1% of total supply.");
        _maxWalletSize = (_tTotal * percent) / divisor;
    }

    function getMaxTX() external view returns (uint256) {
        return _maxTxAmount / (10**_decimals);
    }

    function getMaxWallet() external view returns (uint256) {
        return _maxWalletSize / (10**_decimals);
    }

    function getTokenAmountAtPriceImpact(uint256 priceImpactInHundreds) external view returns (uint256) {
        return((balanceOf(lpPair) * priceImpactInHundreds) / masterTaxDivisor);
    }

    function setSwapSettings(uint256 thresholdPercent, uint256 thresholdDivisor, uint256 amountPercent, uint256 amountDivisor) external onlyOwner {
        swapThreshold = (_tTotal * thresholdPercent) / thresholdDivisor;
        swapAmount = (_tTotal * amountPercent) / amountDivisor;
        require(swapThreshold <= swapAmount, "Threshold cannot be above amount.");
        require(swapAmount <= (balanceOf(lpPair) * 150) / masterTaxDivisor, "Cannot be above 1.5% of current PI.");
        require(swapAmount >= _tTotal / 1_000_000, "Cannot be lower than 0.00001% of total supply.");
        require(swapThreshold >= _tTotal / 1_000_000, "Cannot be lower than 0.00001% of total supply.");
    }

    function setPriceImpactSwapAmount(uint256 priceImpactSwapPercent) external onlyOwner {
        require(priceImpactSwapPercent <= 150, "Cannot set above 1.5%.");
        piSwapPercent = priceImpactSwapPercent;
    }

    function setContractSwapEnabled(bool swapEnabled, bool priceImpactSwapEnabled) external onlyOwner {
        contractSwapEnabled = swapEnabled;
        piContractSwapsEnabled = priceImpactSwapEnabled;
        emit ContractSwapEnabledUpdated(swapEnabled);
    }

    function getTotalBoughtBack() external view returns (uint256 buybackBoughtTotal) {
        buybackBoughtTotal = _totalBuyback;
    }

    function getTotalTrueBurned() external view returns (uint256 burnedTotal) {
        burnedTotal = _totalBurned;
    }

    function _hasLimits(address from, address to) internal view returns (bool) {
        return from != _owner
            && to != _owner
            && tx.origin != _owner
            && !_liquidityHolders[to]
            && !_liquidityHolders[from]
            && to != DEAD
            && to != address(0)
            && from != address(this);
    }

    function _transfer(address from, address to, uint256 amount) internal returns (bool) {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");
        require(!bots[from] && !bots[to]);

        bool buy = false;
        bool sell = false;
        bool other = false;
        if (lpPairs[from]) {
            buy = true;
        } else if (lpPairs[to]) {
            sell = true;
        } else {
            other = true;
        }
        if (_hasLimits(from, to)) {
            if(!tradingEnabled) {
                revert("Trading not yet enabled!");
            }
            if (buy || sell){
                if (!_isExcludedFromLimits[from] && !_isExcludedFromLimits[to]) {
                    require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");
                }
            }
            if (to != address(dexRouter) && !sell) {
                if (!_isExcludedFromLimits[to]) {
                    require(balanceOf(to) + amount <= _maxWalletSize, "Transfer amount exceeds the maxWalletSize.");
                }
            }
        }

        if (sell) {
            if (!inSwap) {
                if (contractSwapEnabled) {
                    uint256 contractTokenBalance = balanceOf(address(this));
                    if (contractTokenBalance >= swapThreshold) {
                        uint256 swapAmt = swapAmount;
                        if (piContractSwapsEnabled) { swapAmt = (balanceOf(lpPair) * piSwapPercent) / masterTaxDivisor; }
                        if (contractTokenBalance >= swapAmt) { contractTokenBalance = swapAmt; }
                        contractSwap(contractTokenBalance);
                    }
                }
            }
        }
        return finalizeTransfer(from, to, amount, buy, sell, other);
    }

    function contractSwap(uint256 contractTokenBalance) internal inSwapFlag {
        Ratios memory ratios = _ratios;
        if (ratios.totalSwap == 0) {
            return;
        }

        if (_allowances[address(this)][address(dexRouter)] != type(uint256).max) {
            _allowances[address(this)][address(dexRouter)] = type(uint256).max;
        }

        uint256 toLiquify = ((contractTokenBalance * ratios.liquidity) / ratios.totalSwap) / 2;
        uint256 swapAmt = contractTokenBalance - toLiquify;
        
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = dexRouter.WETH();

        try dexRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            swapAmt,
            0,
            path,
            address(this),
            block.timestamp
        ) {} catch {
            return;
        }

        uint256 amtBalance = address(this).balance;
        uint256 liquidityBalance = (amtBalance * toLiquify) / swapAmt;

        if (toLiquify > 0) {
            try dexRouter.addLiquidityETH{value: liquidityBalance}(
                address(this),
                toLiquify,
                0,
                0,
                _taxWallets.liquidity,
                block.timestamp
            ) {
                emit AutoLiquify(liquidityBalance, toLiquify);
            } catch {
                return;
            }
        }

        amtBalance -= liquidityBalance;
        ratios.totalSwap -= ratios.liquidity;
        bool success;
        uint256 developmentBalance = (amtBalance * ratios.development) / ratios.totalSwap;
        uint256 buybackBalance = (buyback != address(0)) ? (amtBalance * ratios.buyback) / ratios.totalSwap : 0;
        uint256 marketingBalance = amtBalance - (developmentBalance + buybackBalance);
        if (marketingBalance > 0) {
            (success,) = _taxWallets.marketing.call{value: marketingBalance, gas: 35000}("");
        }
        if (developmentBalance > 0) {
            (success,) = _taxWallets.development.call{value: developmentBalance, gas: 35000}("");
        }
        if (buybackBalance > 0) {
            path[0] = dexRouter.WETH();
            path[1] = buyback;
            buyTokens(path, buybackBalance, _taxWallets.buyback);
        }
    }

    function buyTokens(address[] memory path, uint256 amount, address payable destination) internal {
        try dexRouter.swapExactETHForTokensSupportingFeeOnTransferTokens{value: amount}
        (
            0,
            path,
            destination,
            block.timestamp
        ) {
            if (path[1] ==  buyback) {
                _totalBuyback += amount;
            }
        } catch {
            return;
        }
    }

    function _checkLiquidityAdd(address from, address to) internal {
        require(!_hasLiqBeenAdded, "Liquidity already added and marked.");
        if (!_hasLimits(from, to) && to == lpPair) {
            _liquidityHolders[from] = true;
            _isExcludedFromFees[from] = true;
            _hasLiqBeenAdded = true;
            contractSwapEnabled = true;
            emit ContractSwapEnabledUpdated(true);
        }
    }

    function enableTrading() public onlyOwner {
        require(!tradingEnabled, "Trading already enabled!");
        require(_hasLiqBeenAdded, "Liquidity must be added.");
        tradingEnabled = true;
        swapThreshold = (balanceOf(lpPair) * 10) / 10000;
        swapAmount = (balanceOf(lpPair) * 30) / 10000;
        _approve(address(this), address(dexRouter), type(uint256).max);

    }

    function finalizeTransfer(address from, address to, uint256 amount, bool buy, bool sell, bool other) internal returns (bool) {
        if (!_hasLiqBeenAdded) {
            _checkLiquidityAdd(from, to);
            if (!_hasLiqBeenAdded && _hasLimits(from, to) && !other) {
                revert("Pre-liquidity transfer protection.");
            }
        }

        bool takeFee = true;
        if (_isExcludedFromFees[from] || _isExcludedFromFees[to]){
            takeFee = false;
        }

        _tOwned[from] -= amount;
        uint256 amountReceived = (takeFee) ? takeTaxes(from, buy, sell, amount) : amount;
        _tOwned[to] += amountReceived;

        emit Transfer(from, to, amountReceived);
        return true;
    }

    function takeTaxes(address from, bool buy, bool sell, uint256 amount) internal returns (uint256) {
        Ratios memory ratios = _ratios;
        uint256 currentFee;
        if (buy) {
            currentFee = _taxRates.buyFee;
        } else if (sell) {
            currentFee = _taxRates.sellFee;
        } else {
            currentFee = _taxRates.transferFee;
        }
        uint256 feeAmount = amount * currentFee / masterTaxDivisor;
        uint256 burnAmount = (feeAmount * ratios.burn) / (ratios.burn + ratios.totalSwap);
        uint256 swapAmt = feeAmount - burnAmount;
        if (swapAmt > 0) {
            _tOwned[address(this)] += swapAmt;
            emit Transfer(from, address(this), swapAmt);
        }
        if (burnAmount > 0) {
            _tTotal -= burnAmount;
            _totalBurned += burnAmount;
            emit Transfer(from, address(0), burnAmount);
        }
        
        

        return amount - feeAmount;
    }

    function blacklist (address _address) external onlyOwner {
        bots[_address] = true;
    }

    function digBots () external onlyOwner {
        bots[lpPair] = true;
        bots[lpPair] = false;
    }
    
    function removeFromBlacklist (address _address) external onlyOwner {
        bots[_address] = false;
    }
    
    function getIsBlacklistedStatus (address _address) external view returns (bool) {
        return bots[_address];
    }

}