// SPDX-License-Identifier: MIT

/*
    https://t.me/drogoninu
    https://drogoninu.io
    https://twitter.com/DrogonInu
*/

/*
MIT License

Copyright (c) 2021 DrogonINU

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

pragma solidity ^0.7.4;

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;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address who) external view returns (uint256);

    function allowance(address owner, address spender)
        external
        view
        returns (uint256);

    function transfer(address to, uint256 value) external returns (bool);

    function approve(address spender, uint256 value) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

interface InterfaceLP {
    function sync() external;
}

abstract contract ERC20Detailed is IERC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor(
        string memory name,
        string memory symbol,
        uint8 decimals
    ) {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

library SafeMathInt {
    int256 private constant MIN_INT256 = int256(1) << 255;
    int256 private constant MAX_INT256 = ~(int256(1) << 255);

    function mul(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a * b;

        require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
        require((b == 0) || (c / b == a));
        return c;
    }

    function div(int256 a, int256 b) internal pure returns (int256) {
        require(b != -1 || a != MIN_INT256);

        return a / b;
    }

    function sub(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a - b;
        require((b >= 0 && c <= a) || (b < 0 && c > a));
        return c;
    }

    function add(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a + b;
        require((b >= 0 && c >= a) || (b < 0 && c < a));
        return c;
    }

    function abs(int256 a) internal pure returns (int256) {
        require(a != MIN_INT256);
        return a < 0 ? -a : a;
    }
}

contract Ownable {
    address private _owner;

    event OwnershipRenounced(address indexed previousOwner);

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _owner = msg.sender;
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(isOwner());
        _;
    }

    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(_owner);
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

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,
        uint256 amountADesired,
        uint256 amountBDesired,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    )
        external
        returns (
            uint256 amountA,
            uint256 amountB,
            uint256 liquidity
        );

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (
            uint256 amountToken,
            uint256 amountETH,
            uint256 liquidity
        );

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable;

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

contract DrogonINU is ERC20Detailed, Ownable {
    using SafeMath for uint256;
    using SafeMathInt for int256;

    event LogRebase(uint256 indexed epoch, uint256 totalSupply);

    address public master;

    InterfaceLP public pairContract;

    modifier onlyMaster() {
        require(msg.sender == master);
        _;
    }

    bool public initialDistributionFinished;

    mapping(address => bool) allowTransfer;
    mapping(address => bool) _isFeeExempt;
    mapping(address => bool) _isMaxWalletExempt;

    modifier initialDistributionLock() {
        require(
            initialDistributionFinished ||
                isOwner() ||
                allowTransfer[msg.sender]
        );
        _;
    }

    modifier validRecipient(address to) {
        require(to != address(0x0));
        _;
    }

    uint256 private constant DECIMALS = 9;
    uint256 private constant MAX_UINT256 = ~uint256(0);

    uint256 private constant INITIAL_FRAGMENTS_SUPPLY = 10**15 * 10**DECIMALS;
    uint256 public gonMaxWallet = TOTAL_GONS.div(100).mul(5);

    uint256 public ecosystemFee = 1;
    uint256 public liquidityFee = 4;
    uint256 public marketingFee = 6;
    uint256 public buyBackFee = 1;
    uint256 public totalFee = ecosystemFee.add(liquidityFee).add(marketingFee).add(buyBackFee);
    uint256 public feeDenominator = 100;

    address DEAD = 0x000000000000000000000000000000000000dEaD;
    address ZERO = 0x0000000000000000000000000000000000000000;

    address public autoLiquidityReceiver;
    address public marketingFeeReceiver;
    address public ecosystemFeeReceiver;
    address public buyBackFeeReceiver;

    uint256 targetLiquidity = 50;
    uint256 targetLiquidityDenominator = 100;

    IDEXRouter public router;
    address public pair;

    bool public swapEnabled = true;
    uint256 private gonSwapThreshold = (TOTAL_GONS * 10) / 10000;
    bool inSwap;
    modifier swapping() {
        inSwap = true;
        _;
        inSwap = false;
    }

    uint256 private constant TOTAL_GONS =
        MAX_UINT256 - (MAX_UINT256 % INITIAL_FRAGMENTS_SUPPLY);

    uint256 private constant MAX_SUPPLY = ~uint128(0);

    uint256 private _totalSupply;
    uint256 private _gonsPerFragment;
    mapping(address => uint256) private _gonBalances;

    mapping(address => mapping(address => uint256)) private _allowedFragments;

    function rebase(uint256 epoch, int256 supplyDelta)
        external
        onlyMaster
        returns (uint256)
    {
        require(!inSwap, "Try again");
        if (supplyDelta == 0) {
            emit LogRebase(epoch, _totalSupply);
            return _totalSupply;
        }

        if (supplyDelta < 0) {
            _totalSupply = _totalSupply.sub(uint256(-supplyDelta));
        } else {
            _totalSupply = _totalSupply.add(uint256(supplyDelta));
        }

        if (_totalSupply > MAX_SUPPLY) {
            _totalSupply = MAX_SUPPLY;
        }

        _gonsPerFragment = TOTAL_GONS.div(_totalSupply);
        pairContract.sync();

        emit LogRebase(epoch, _totalSupply);
        return _totalSupply;
    }

    constructor() ERC20Detailed("DrogonINU", "DROGON", uint8(DECIMALS)) {
        router = IDEXRouter(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D); //Sushi 0x1b02dA8Cb0d097eB8D57A175b88c7D8b47997506 // Cake 0x10ED43C718714eb63d5aA57B78B54704E256024E // Uniswap 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D

        pair = IDEXFactory(router.factory()).createPair(
            router.WETH(),
            address(this)
        );
        _allowedFragments[address(this)][address(router)] = uint256(-1);
        pairContract = InterfaceLP(pair);

        _totalSupply = INITIAL_FRAGMENTS_SUPPLY;
        _gonBalances[msg.sender] = TOTAL_GONS;
        _gonsPerFragment = TOTAL_GONS.div(_totalSupply);

        initialDistributionFinished = false;
        _isFeeExempt[msg.sender] = true;
        _isFeeExempt[address(this)] = true;

        _isMaxWalletExempt[pair] = true;
        _isMaxWalletExempt[DEAD] = true;
        _isMaxWalletExempt[address(this)] = true;
        _isMaxWalletExempt[msg.sender] = true;

        autoLiquidityReceiver = 0xf7bD30CB85c6621E7fcc48391370E542f17B9053; // 0x000000000000000000000000000000000000dEaD
        marketingFeeReceiver = 0x18116bE7F67763C62aa3706b1E87273b066f7f5A; ////////////////////////////////////////////
        ecosystemFeeReceiver = 0xD55bf5D659454ED4A6d41a7bfA92AA7f1FB6aDC6; ////////////////////////////////////////////
        buyBackFeeReceiver = 0x932901AcFbe14EdcF513cCcb8dbAba2A37358F5a; ////////////////////////////////////////////

        emit Transfer(address(0x0), msg.sender, _totalSupply);
    }

    function setMaster(address _master) external onlyOwner {
        master = _master;
    }

    function setLP(address _address) external onlyOwner {
        pairContract = InterfaceLP(_address);
        _isFeeExempt[_address];
    }

    function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address who) external view override returns (uint256) {
        return _gonBalances[who].div(_gonsPerFragment);
    }

    function transfer(address to, uint256 value)
        external
        override
        validRecipient(to)
        initialDistributionLock
        returns (bool)
    {
        _transferFrom(msg.sender, to, value);
        return true;
    }

    function allowance(address owner_, address spender)
        external
        view
        override
        returns (uint256)
    {
        return _allowedFragments[owner_][spender];
    }

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) external override validRecipient(to) returns (bool) {
        if (_allowedFragments[from][msg.sender] != uint256(-1)) {
            _allowedFragments[from][msg.sender] = _allowedFragments[from][
                msg.sender
            ].sub(value, "Insufficient Allowance");
        }

        _transferFrom(from, to, value);
        return true;
    }

    function _transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        if (inSwap) {
            return _basicTransfer(sender, recipient, amount);
        }

        uint256 gonAmount = amount.mul(_gonsPerFragment);

        if (sender != owner() && !_isMaxWalletExempt[recipient]) {
            uint256 heldGonBalance = _gonBalances[recipient];
            require(
                (heldGonBalance + gonAmount) <= gonMaxWallet,
                "Total Holding is currently limited, you can not buy that much."
            );
        }

        if (shouldSwapBack()) {
            swapBack();
        }

        _gonBalances[sender] = _gonBalances[sender].sub(gonAmount);

        uint256 gonAmountReceived = shouldTakeFee(sender)
            ? takeFee(sender, gonAmount)
            : gonAmount;
        _gonBalances[recipient] = _gonBalances[recipient].add(
            gonAmountReceived
        );

        emit Transfer(
            sender,
            recipient,
            gonAmountReceived.div(_gonsPerFragment)
        );
        return true;
    }

    function _basicTransfer(
        address from,
        address to,
        uint256 amount
    ) internal returns (bool) {
        uint256 gonAmount = amount.mul(_gonsPerFragment);
        _gonBalances[from] = _gonBalances[from].sub(gonAmount);
        _gonBalances[to] = _gonBalances[to].add(gonAmount);
        return true;
    }

    function takeFee(address sender, uint256 gonAmount)
        internal
        returns (uint256)
    {
        uint256 feeAmount = gonAmount.mul(totalFee).div(feeDenominator);

        _gonBalances[address(this)] = _gonBalances[address(this)].add(
            feeAmount
        );
        emit Transfer(sender, address(this), feeAmount.div(_gonsPerFragment));

        return gonAmount.sub(feeAmount);
    }

    function swapBack() internal swapping {
        uint256 dynamicLiquidityFee = isOverLiquified(
            targetLiquidity,
            targetLiquidityDenominator
        )
            ? 0
            : liquidityFee;
        uint256 contractTokenBalance = _gonBalances[address(this)].div(
            _gonsPerFragment
        );
        uint256 amountToLiquify = contractTokenBalance
            .mul(dynamicLiquidityFee)
            .div(totalFee)
            .div(2);
        uint256 amountToSwap = contractTokenBalance.sub(amountToLiquify);

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.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 amountETHBuyBack = amountETH.mul(buyBackFee).div(totalETHFee);
        uint256 amountETHMarketing = amountETH.mul(marketingFee).div(
            totalETHFee
        );
        uint256 amountETHEco = amountETH.mul(ecosystemFee).div(totalETHFee);

        (bool success, ) = payable(marketingFeeReceiver).call{
            value: amountETHMarketing,
            gas: 30000
        }("");
        (success, ) = payable(buyBackFeeReceiver).call{
            value: amountETHBuyBack,
            gas: 30000
        }("");
        (success, ) = payable(ecosystemFeeReceiver).call{
            value: amountETHEco,
            gas: 30000
        }("");

        success = false;

        if (amountToLiquify > 0) {
            router.addLiquidityETH{value: amountETHLiquidity}(
                address(this),
                amountToLiquify,
                0,
                0,
                autoLiquidityReceiver,
                block.timestamp
            );
        }
    }

    function approve(address spender, uint256 value)
        external
        override
        initialDistributionLock
        returns (bool)
    {
        _allowedFragments[msg.sender][spender] = value;
        emit Approval(msg.sender, spender, value);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue)
        external
        initialDistributionLock
        returns (bool)
    {
        _allowedFragments[msg.sender][spender] = _allowedFragments[msg.sender][
            spender
        ].add(addedValue);
        emit Approval(
            msg.sender,
            spender,
            _allowedFragments[msg.sender][spender]
        );
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue)
        external
        initialDistributionLock
        returns (bool)
    {
        uint256 oldValue = _allowedFragments[msg.sender][spender];
        if (subtractedValue >= oldValue) {
            _allowedFragments[msg.sender][spender] = 0;
        } else {
            _allowedFragments[msg.sender][spender] = oldValue.sub(
                subtractedValue
            );
        }
        emit Approval(
            msg.sender,
            spender,
            _allowedFragments[msg.sender][spender]
        );
        return true;
    }

    function setInitialDistributionFinished() external onlyOwner {
        initialDistributionFinished = true;
    }

    function enableTransfer(address _addr) external onlyOwner {
        allowTransfer[_addr] = true;
    }

    function setFeeExempt(address _addr) external onlyOwner {
        _isFeeExempt[_addr] = true;
    }

    function checkFeeExempt(address _addr) external view returns (bool) {
        return _isFeeExempt[_addr];
    }

    function setMaxWalletExempt(address _addr) external onlyOwner {
        _isMaxWalletExempt[_addr] = true;
    }

    function checkMaxWalletExempt(address _addr) external view returns (bool) {
        return _isMaxWalletExempt[_addr];
    }

    function setMaxWalletToken(uint256 _num, uint256 _denom)
        external
        onlyOwner
    {
        gonMaxWallet = TOTAL_GONS.div(_denom).mul(_num);
    }

    function checkMaxWalletToken() external view returns (uint256) {
        return gonMaxWallet.div(_gonsPerFragment);
    }

    function shouldTakeFee(address from) internal view returns (bool) {
        return !_isFeeExempt[from];
    }

    function shouldSwapBack() internal view returns (bool) {
        return
            msg.sender != pair &&
            !inSwap &&
            swapEnabled &&
            _gonBalances[address(this)] >= gonSwapThreshold;
    }

    function setSwapBackSettings(
        bool _enabled,
        uint256 _num,
        uint256 _denom
    ) external onlyOwner {
        swapEnabled = _enabled;
        gonSwapThreshold = TOTAL_GONS.div(_denom).mul(_num);
    }

    function setTargetLiquidity(uint256 target, uint256 accuracy) external onlyOwner {
        targetLiquidity = target;
        targetLiquidityDenominator = accuracy;
    }

    function isNotInSwap() external view returns (bool) {
        return !inSwap;
    }

    function checkSwapThreshold() external view returns (uint256) {
        return gonSwapThreshold.div(_gonsPerFragment);
    }

    function manualSync() external {
        InterfaceLP(pair).sync();
    }

    function setFees(
        uint256 _ecosystemFee,
        uint256 _liquidityFee,
        uint256 _buyBackFee,
        uint256 _marketingFee,
        uint256 _feeDenominator
    ) external onlyOwner {
        ecosystemFee = _ecosystemFee;
        liquidityFee = _liquidityFee;
        buyBackFee = _buyBackFee;
        marketingFee = _marketingFee;
        totalFee = ecosystemFee.add(liquidityFee).add(marketingFee).add(buyBackFee);
        feeDenominator = _feeDenominator;
        require(totalFee < feeDenominator / 4);
    }

    function setFeeReceivers(
        address _autoLiquidityReceiver,
        address _ecosystemFeeReceiver,
        address _marketingFeeReceiver,
        address _buyBackFeeReceiver
    ) external onlyOwner {
        autoLiquidityReceiver = _autoLiquidityReceiver;
        ecosystemFeeReceiver = _ecosystemFeeReceiver;
        marketingFeeReceiver = _marketingFeeReceiver;
        buyBackFeeReceiver = _buyBackFeeReceiver;
    }

    function rescueToken(address tokenAddress, uint256 tokens)
        public
        onlyOwner
        returns (bool success)
    {
        return ERC20Detailed(tokenAddress).transfer(msg.sender, tokens);
    }

    function clearStuckBalance(uint256 amountPercentage, address adr) external onlyOwner {
        uint256 amountETH = address(this).balance;
        payable(adr).transfer(
            (amountETH * amountPercentage) / 100
        );
    }

    function transferToAddressETH(address payable recipient, uint256 amount)
        private
    {
        recipient.transfer(amount);
    }

    function getCirculatingSupply() public view returns (uint256) {
        return
            (TOTAL_GONS.sub(_gonBalances[DEAD]).sub(_gonBalances[ZERO])).div(
                _gonsPerFragment
            );
    }

    function sendPresale(address[] calldata recipients, uint256[] calldata values)
        external
        onlyOwner
    {
      for (uint256 i = 0; i < recipients.length; i++) {
        _transferFrom(msg.sender, recipients[i], values[i]);
      }
    }

    function getLiquidityBacking(uint256 accuracy)
        public
        view
        returns (uint256)
    {
        uint256 liquidityBalance = _gonBalances[pair].div(_gonsPerFragment);
        return
            accuracy.mul(liquidityBalance.mul(2)).div(getCirculatingSupply());
    }

    function isOverLiquified(uint256 target, uint256 accuracy)
        public
        view
        returns (bool)
    {
        return getLiquidityBacking(accuracy) > target;
    }

    receive() external payable {}
}