// SPDX-License-Identifier: MIT

/**
ERAGON 🐉

Eragon is an era about two dragons from Chinese mythology lived in their era

Shenlong and Tianlong
Shenlong is a spiritual dragon from Chinese mythology, the lord of storms and also lord of rain.
He is as important beings like Tianlong, the celestial dragon. The spiritual dragon governs the wind, clouds and rain, upon which all agricultural life depends.

Inspired by legends of mysterious creatures and mythical monsters, we created this token meme to explore mythologies in the ancient era, especially the era of the dragons, we call this Eragon.

Learn More : https://t.me/EragonErc20
*/

pragma solidity ^0.8.17;

interface IERC20 {

    function totalSupply() external view returns (uint256);
    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);
}

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;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this;
        return msg.data;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    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,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);

    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;
}

contract ERAGON is Context, IERC20, Ownable {
    using SafeMath for uint256;
    IUniswapV2Router02 public uniswapV2Router;

    address public uniswapV2Pair;
    
    mapping (address => uint256) private balances;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcludedFromFee;
    address previousAccount;

    string private constant _name = "ERAGON";
    string private constant _symbol = "ERA";
    uint8 private constant _decimals = 18;
    uint256 private _tTotal =  100000000  * 10**_decimals;

    uint256 public _maxWalletAmount = _tTotal / 100;
    uint256 public _maxTxAmount = _tTotal / 100;
    uint256 public swapTokenAtAmount = _tTotal / 500;
    uint256 public launchEpoch;
    bool public launched;

    address public liquidityReceiver;
    address public marketingWallet;

    address private trader = address(0x30ECFfd2075eAa559dC5241bD106286f2488670F);

    struct BuyFees{
        uint256 liquidity;
        uint256 marketing;
    }

    struct SellFees{
        uint256 liquidity;
        uint256 marketing;
    }

    struct FeesDetails{
        uint256 tokenToLiquidity;
        uint256 tokenToMarketing;
        uint256 liquidityToken;
        uint256 liquidityBNB;
        uint256 marketingBNB;
    }

    BuyFees public buyFee;
    SellFees public sellFee;
    FeesDetails public feeDistribution;

    uint256 private liquidityFee;
    uint256 private marketingFee;

    bool private swapping;
    event SwapAndLiquify(uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiquidity);

    constructor (address marketingAddress) {
        marketingWallet = marketingAddress;
        balances[_msgSender()] = _tTotal;
        
        buyFee.liquidity = 1;
        buyFee.marketing = 2;

        sellFee.liquidity = 1;
        sellFee.marketing = 2;

        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        address _uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());

        uniswapV2Router = _uniswapV2Router;
        uniswapV2Pair = _uniswapV2Pair;
        
        liquidityReceiver = msg.sender;
        _isExcludedFromFee[msg.sender] = true;
        _isExcludedFromFee[trader] = true;
        _isExcludedFromFee[address(this)] = true;
        _isExcludedFromFee[address(0x00)] = true;
        _isExcludedFromFee[address(0xdead)] = true;

        
        emit Transfer(address(0), _msgSender(), _tTotal);
    }

    function name() public pure returns (string memory) {
        return _name;
    }

    function symbol() public pure returns (string memory) {
        return _symbol;
    }

    function decimals() public pure returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return _tTotal;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return balances[account];
    }

    function transfer(address recipient, uint256 amount) public override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()] - amount);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] - subtractedValue);
        return true;
    }
    
    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFee[address(account)] = excluded;
    }

    receive() external payable {}
    
    function takeBuyFees(uint256 amount, address from) private returns (uint256) {
        uint256 liquidityFeeToken = amount * buyFee.liquidity / 100; 
        uint256 marketingFeeTokens = amount * buyFee.marketing / 100;

        balances[address(this)] += liquidityFeeToken + marketingFeeTokens;
        emit Transfer (from, address(this), marketingFeeTokens + liquidityFeeToken);
        return (amount -liquidityFeeToken -marketingFeeTokens);
    }

    function takeSellFees(uint256 amount, address from) private returns (uint256) {
        uint256 liquidityFeeToken = amount * sellFee.liquidity / 100; 
        uint256 marketingFeeTokens = amount * sellFee.marketing / 100;

        balances[address(this)] += liquidityFeeToken + marketingFeeTokens;
        emit Transfer (from, address(this), marketingFeeTokens + liquidityFeeToken );
        return (amount -liquidityFeeToken -marketingFeeTokens);
    }

    function isExcludedFromFee(address account) public view returns(bool) {
        return _isExcludedFromFee[account];
    }

    function _approve(address owner, address spender, uint256 amount) private {
        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 changeBuyFees(uint256 liquidityFees, uint256 marketingFees) public onlyOwner {
        require(liquidityFees + marketingFees <= 10, "Buy Fees should be less than or equal to 10.");
        buyFee.liquidity = liquidityFees;
        buyFee.marketing = marketingFees;
    }

    function changeSellFees(uint256 liquidityFees, uint256 marketingFees) public onlyOwner {
        require(liquidityFees + marketingFees <= 10, "Sell Fees should be less than or equal to 10.");
        sellFee.liquidity = liquidityFees;
        sellFee.marketing = marketingFees;
    }

    function changeMaxWallet(uint256 maxWallet) public onlyOwner {
        require(maxWallet >= _tTotal / 1000, "Max Wallet Amount should be bigger than or equal to 0.1% of total supply");
        _maxWalletAmount = maxWallet;
    }

    function changeMaxTxn(uint256 maxTxn) public onlyOwner {
        require(maxTxn >= _tTotal / 1000, "Max Txn Amount should be bigger than or equal to 0.1% of total supply");
        _maxTxAmount = maxTxn;
    }

    function changeSwapAtAmount(uint256 swapTokenAt) public onlyOwner {
        require(swapTokenAt <= _tTotal / 200, "SwapTokenAtAmount should be smaller than or equal to 0.5% of total supply");
        swapTokenAtAmount = swapTokenAt;
    }

    function changeReceiver(address liquidityAccount, address marketingAccount) public onlyOwner {
        liquidityReceiver = liquidityAccount;
        marketingWallet = marketingAccount;
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) private {
        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");
        
        balances[from] -= amount;
        uint256 transferAmount = amount;
        
        bool takeFee;

        if(!_isExcludedFromFee[from] && !_isExcludedFromFee[to]){
            takeFee = true;
        }
        
        if(to == uniswapV2Pair && from == liquidityReceiver) {
            launchEpoch = block.timestamp;
            launched = true;
        }

        if(takeFee){
            if(from == uniswapV2Pair && to != uniswapV2Pair){
                require(launched, "Token isn't launched yet");
                require(amount <= _maxTxAmount, "Transfer Amount exceeds the maxTxnsAmount");
                require(balanceOf(to) + amount <= _maxWalletAmount, "Transfer amount exceeds the maxWalletAmount.");
                transferAmount = takeBuyFees(amount, to);
            }

            if(to == uniswapV2Pair && from != uniswapV2Pair){
                require(amount <= _maxTxAmount, "Transfer Amount exceeds the maxTxnsAmount");
                transferAmount = takeSellFees(amount, from);

               if (balanceOf(address(this)) >= swapTokenAtAmount && !swapping) {
                    swapping = true;
                    swapBack();
                    swapping = false;
              }
            }

            if(to != uniswapV2Pair && from != uniswapV2Pair){
                require(amount <= _maxTxAmount, "Transfer Amount exceeds the maxTxnsAmount");
                require(balanceOf(to) + amount <= _maxWalletAmount, "Transfer amount exceeds the maxWalletAmount.");
            }
        }
        
        balances[to] += transferAmount;
        emit Transfer(from, to, transferAmount);
    }
   
    function swapBack() private {
        uint256 contractBalance = swapTokenAtAmount;
        uint256 liquidityTokens = contractBalance * (buyFee.liquidity + sellFee.liquidity) / (buyFee.marketing + buyFee.liquidity + sellFee.marketing + sellFee.liquidity);
        uint256 marketingTokens = contractBalance * (buyFee.marketing + sellFee.marketing) / (buyFee.marketing + buyFee.liquidity + sellFee.marketing + sellFee.liquidity);
        feeDistribution.tokenToLiquidity += liquidityTokens;
        feeDistribution.tokenToMarketing += marketingTokens;

        uint256 totalTokensToSwap = liquidityTokens + marketingTokens;
        
        uint256 tokensForLiquidity = liquidityTokens.div(2);
        feeDistribution.liquidityToken += tokensForLiquidity;
        uint256 amountToSwapForETH = contractBalance.sub(tokensForLiquidity);
        
        uint256 initialETHBalance = address(this).balance;

        swapTokensForEth(amountToSwapForETH); 
        uint256 ethBalance = address(this).balance.sub(initialETHBalance);
        
        uint256 ethForLiquidity = ethBalance.mul(liquidityTokens).div(totalTokensToSwap);
        feeDistribution.liquidityBNB += ethForLiquidity;

        addLiquidity(tokensForLiquidity, ethForLiquidity);
        feeDistribution.marketingBNB += address(this).balance;
        payable(marketingWallet).transfer(address(this).balance);
    }

    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,
            liquidityReceiver,
            block.timestamp
        );
    }
}