/**

Etheria and Maxtic's Adventure with Ko the Dragon: A Tale of Crypto Wonders, a magical creature that held the secrets to a wondrous crypto project.

Website: https://KoTheDragon.com
Twitter: https://twitter.com/KoTheDragon
Telegram: https://t.me/KoTheDragon

*/

// SPDX-License-Identifier: Unlicensed

pragma solidity ^0.8.20;

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
}

abstract contract Ownable is Context {
    address private _owner;
    bool ownerRemoved;
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _transferOwnership(_msgSender());
    }

    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    function owner() public view virtual returns (address) {
        if (ownerRemoved) {
            return address(0);
        }
        return _owner;
    }

    function _checkOwner() internal view virtual {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
    }

    function renounceOwnership() public virtual onlyOwner {
        ownerRemoved = true;
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

interface IERC20 {
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );

    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address to, 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 from,
        address to,
        uint256 amount
    ) external returns (bool);
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(
        address account
    ) public view virtual override returns (uint256) {
        return _balances[account];
    }

    function transfer(
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    function allowance(
        address owner,
        address spender
    ) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(
        address spender,
        uint256 amount
    ) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    function increaseAllowance(
        address spender,
        uint256 addedValue
    ) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    function decreaseAllowance(
        address spender,
        uint256 subtractedValue
    ) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(
            currentAllowance >= subtractedValue,
            "ERC20: decreased allowance below zero"
        );
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(
            fromBalance >= amount,
            "ERC20: transfer amount exceeds balance"
        );
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(
                currentAllowance >= amount,
                "ERC20: insufficient allowance"
            );
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

interface IUniswapV2Factory {
    function createPair(
        address tokenA,
        address tokenB
    ) external returns (address pair);
}

interface IUniswapV2Router02 {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    )
        external
        payable
        returns (uint256 amountToken, uint256 amountETH, uint256 liquidity);

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;
}

contract KoTheDragon is ERC20, Ownable {
    using SafeMath for uint256;

    IUniswapV2Router02 public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;
    bool private swapping;
    bool public tradingActive = false;
    bool public limitsInEffect = true;

    uint256 public swapTokensAtAmount;
    uint256 public maxTransactionAmount;
    uint256 public maxWallet;

    address public marketingWallet;
    address public kostakingpoolWallet;

    struct Taxes {
        uint256 marketing;
        uint256 liquidity;
        uint256 kostakingpool;
        uint256 total;
    }
    Taxes public buyTax;
    Taxes public sellTax;

    uint256 private tokensForMarketing;
    uint256 private tokensForLiquidity;
    uint256 private tokensForKoStakingPool;

    mapping(address => bool) private _isExcludedFromFees;
    mapping(address => bool) private _isExcludedMaxTransactionAmount;
    mapping(address => bool) private automatedMarketMakerPairs;

    event ExcludeFromFees(address indexed account, bool isExcluded);
    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);
    event SwapAndLiquidity(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );

    constructor() ERC20("Ko The Dragon", "KO") {
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        );
        excludeFromMaxTransaction(address(_uniswapV2Router), true);
        uniswapV2Router = _uniswapV2Router;

        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
            .createPair(address(this), _uniswapV2Router.WETH());
        excludeFromMaxTransaction(address(uniswapV2Pair), true);
        _setAutomatedMarketMakerPair(address(uniswapV2Pair), true);

        uint256 totalSupply = 10000000 * 10 ** decimals();

        maxWallet = maxTransactionAmount = (totalSupply * 2) / 100;
        swapTokensAtAmount = (totalSupply * 1) / 1000;

        marketingWallet = _msgSender();
        kostakingpoolWallet = _msgSender();

        buyTax = Taxes(5, 0, 5, 10);
        sellTax = Taxes(5, 0, 5, 30);

        excludeFromFees(owner(), true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);

        excludeFromMaxTransaction(owner(), true);
        excludeFromMaxTransaction(address(this), true);
        excludeFromMaxTransaction(address(0xdead), true);

        _mint(_msgSender(), totalSupply);
    }

    receive() external payable {}

    function enableTrading() external onlyOwner {
        require(tradingActive == false, "The trading has been opened.");
        tradingActive = true;
    }

    function removeLimits() external onlyOwner {
        require(limitsInEffect == true, "The limits has been removed.");
        limitsInEffect = false;
    }

    function setKoFees(
        uint256 _buyMarketing,
        uint256 _buyLiquidity,
        uint256 _buyKoStakingPool,
        uint256 _sellMarketing,
        uint256 _sellLiquidity,
        uint256 _sellKoStakingPool
    ) external onlyOwner {
        buyTax = Taxes(
            _buyMarketing,
            _buyLiquidity,
            _buyKoStakingPool,
            _buyMarketing + _buyLiquidity + _buyKoStakingPool
        );
        sellTax = Taxes(
            _sellMarketing,
            _sellLiquidity,
            _sellKoStakingPool,
            _sellMarketing + _sellLiquidity + _sellKoStakingPool
        );
    }

    function updateMarketingWallet(
        address _marketingWallet
    ) external onlyOwner {
        marketingWallet = _marketingWallet;
    }

    function updateKoStakingPool(address _kostakingpoolWallet) external onlyOwner {
        kostakingpoolWallet = _kostakingpoolWallet;
    }

    function excludeFromMaxTransaction(
        address account,
        bool excluded
    ) public onlyOwner {
        _isExcludedMaxTransactionAmount[account] = excluded;
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;
        emit ExcludeFromFees(account, excluded);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;
        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {
        require(from != address(0), "ERC20: transfer from the zero address.");
        require(to != address(0), "ERC20: transfer to the zero address.");
        require(
            amount > 0,
            "ERC20: Transfer amount must be greater than zero."
        );

        if (
            from != owner() &&
            to != owner() &&
            to != address(0) &&
            to != address(0xdead) &&
            !swapping
        ) {
            if (tradingActive == false) {
                require(
                    _isExcludedFromFees[from] || _isExcludedFromFees[to],
                    "ERC20: Trading is not active."
                );
            }

            if (limitsInEffect == true) {
                if (
                    automatedMarketMakerPairs[from] &&
                    !_isExcludedMaxTransactionAmount[to]
                ) {
                    require(
                        amount <= maxTransactionAmount,
                        "ERC20: Buy transfer amount exceeds the max transaction amount."
                    );
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "ERC20: Max wallet exceeded."
                    );
                } else if (
                    automatedMarketMakerPairs[to] &&
                    !_isExcludedMaxTransactionAmount[from]
                ) {
                    require(
                        amount <= maxTransactionAmount,
                        "ERC20: Sell transfer amount exceeds the max transaction amount."
                    );
                } else if (!_isExcludedMaxTransactionAmount[to]) {
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "ERC20: Max wallet exceeded."
                    );
                }
            } else {
                if (
                    automatedMarketMakerPairs[to] &&
                    !_isExcludedMaxTransactionAmount[from]
                ) {
                    require(
                        amount <= maxTransactionAmount / 1000,
                        "ERC20: Sell transfer amount exceeds the max transaction amount."
                    );
                }
            }
        }

        bool canSwap = balanceOf(address(this)) >= swapTokensAtAmount;
        if (
            canSwap &&
            !swapping &&
            !automatedMarketMakerPairs[from] &&
            !_isExcludedFromFees[from] &&
            !_isExcludedFromFees[to]
        ) {
            swapping = true;
            swapBack();
            swapping = false;
        }

        bool takeFee = !swapping;
        if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }

        uint256 fees = 0;
        if (takeFee) {
            if (automatedMarketMakerPairs[to] && sellTax.total > 0) {
                fees = amount.mul(sellTax.total).div(100);
                tokensForLiquidity +=
                    (fees * sellTax.liquidity) /
                    sellTax.total;
                tokensForMarketing +=
                    (fees * sellTax.marketing) /
                    sellTax.total;
                tokensForKoStakingPool += (fees * sellTax.kostakingpool) / sellTax.total;
            } else if (automatedMarketMakerPairs[from] && buyTax.total > 0) {
                fees = amount.mul(buyTax.total).div(100);
                tokensForLiquidity += (fees * buyTax.liquidity) / buyTax.total;
                tokensForMarketing += (fees * buyTax.marketing) / buyTax.total;
                tokensForKoStakingPool += (fees * buyTax.kostakingpool) / buyTax.total;
            }

            if (fees > 0) {
                super._transfer(from, address(this), fees);
            }
            amount -= fees;
        }
        super._transfer(from, to, amount);
    }

    function swapTokensForEth(uint256 tokenAmount) private {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        _approve(address(this), address(uniswapV2Router), tokenAmount);
        uniswapV2Router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0,
            0,
            address(0xdead),
            block.timestamp
        );
    }

    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForLiquidity +
            tokensForMarketing +
            tokensForKoStakingPool;
        bool marketingTransferSuccess;
        bool kostakingpoolTransferSuccess;

        if (contractBalance == 0 || totalTokensToSwap == 0) {
            return;
        }

        if (contractBalance > swapTokensAtAmount * 20) {
            contractBalance = swapTokensAtAmount * 20;
        }

        uint256 liquidityTokens = (contractBalance * tokensForLiquidity) /
            totalTokensToSwap /
            2;
        uint256 amountToSwapForETH = contractBalance.sub(liquidityTokens);

        uint256 initialETHBalance = address(this).balance;

        swapTokensForEth(amountToSwapForETH);

        uint256 ethBalance = address(this).balance.sub(initialETHBalance);

        uint256 ethForMarketing = ethBalance.mul(tokensForMarketing).div(
            totalTokensToSwap
        );
        uint256 ethForKoStakingPool = ethBalance.mul(tokensForKoStakingPool).div(
            totalTokensToSwap
        );
        uint256 ethForLiquidity = ethBalance - ethForMarketing - ethForKoStakingPool;

        tokensForLiquidity = 0;
        tokensForMarketing = 0;
        tokensForKoStakingPool = 0;

        if (liquidityTokens > 0 && ethForLiquidity > 0) {
            addLiquidity(liquidityTokens, ethForLiquidity);
            emit SwapAndLiquidity(
                amountToSwapForETH,
                ethForLiquidity,
                tokensForLiquidity
            );
        }

        (kostakingpoolTransferSuccess, ) = address(kostakingpoolWallet).call{
            value: ethForKoStakingPool
        }("");

        (marketingTransferSuccess, ) = address(marketingWallet).call{
            value: address(this).balance
        }("");
    }
}