/**
*/

// SPDX-License-Identifier: Unlicensed
/**


     Our concept is simple. $RU and $UA will be launched on erc20 simultaneously. 
     One hour after the trading is live, the one with less volume will be "defeated,"
     and its liquidity will be pulled out and injected into the other token as a buyback and burn. 
     We will then open an official chat of the winning coin, and it will be the one that will be pushed.
   
   Twitter - https://twitter.com/RUvsUAerc20
   Telegram - https://t.me/RUvsUAchannel

**/
pragma solidity ^0.8.18;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
}

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
    );
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB)
        external
        returns (address pair);
}

interface IUniswapV2Router02 {
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external;

    function factory() external pure returns (address);

    function WETH() external pure returns (address);
}

contract Russia is Context, IERC20 {
    IUniswapV2Router02 immutable uniswapV2Router;
    address immutable uniswapV2Pair;
    address immutable WETH;
    address payable immutable marketingWallet;

    address public _owner = msg.sender;
    uint8 private launch;
    uint8 private inSwapAndLiquify;

    uint256 private _totalSupply        = 10_000_000e18;
    uint256 public maxTxAmount = 200_000e18;
    uint256 private constant onePercent =   100_000e18;
    uint256 private constant minSwap    =     50_000e18;

    uint256 public buyTax;
    uint256 public sellTax;
    uint256 public burnRate = 100;

    uint256 private launchBlock;
  
    uint256 public _transactionVolumeCurrent;
    uint256 public _transactionVolumePrevious;
    uint256 public _lastBucketTime = block.timestamp;
    uint256 private constant _bucketDuration = 60 minutes;

    mapping(address => uint256) private _balance;
    mapping(address => mapping(address => uint256)) private _allowances;
    mapping(address => bool) private _isExcludedFromFeeWallet;

    function onlyOwner() internal view {
        require(_owner == msg.sender);
    }

    constructor() {
        uniswapV2Router = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        );
        WETH = uniswapV2Router.WETH();
        buyTax = 300;
        sellTax = 300;

        uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(
            address(this),
            WETH
        );

        marketingWallet = payable(0x9Ea7EE0B95f640e1020b25df030c73033eA5113B);
        _balance[msg.sender] = _totalSupply;

        _isExcludedFromFeeWallet[marketingWallet] = true;
        _isExcludedFromFeeWallet[msg.sender] = true;
        _isExcludedFromFeeWallet[address(this)] = true;
        _allowances[address(this)][address(uniswapV2Router)] = type(uint256)
            .max;
        _allowances[msg.sender][address(uniswapV2Router)] = type(uint256).max;
        _allowances[marketingWallet][address(uniswapV2Router)] = type(uint256)
            .max;

        emit Transfer(address(0), _msgSender(), _totalSupply);
    }

    function name() public pure returns (string memory) {
        return "Russia";
    }

    function symbol() public pure returns (string memory) {
        return "$RU";
    }

    function decimals() public pure returns (uint8) {
        return 18;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balance[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 _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 openTrading() external  {
        onlyOwner();
        launch = 1;
        launchBlock = block.number;
    }

    function addExcludedWallet(address wallet) external {
        onlyOwner();
        _isExcludedFromFeeWallet[wallet] = true;
    }

    function removeLimits() external  {
        onlyOwner();
        maxTxAmount = _totalSupply;
    }

    function changeTax(uint256 newBuyTax, uint256 newSellTax, uint256 newBurnRate)
        external
        
    {
        onlyOwner();
        require(newBuyTax + newSellTax + newBurnRate <= 20, "Taxes more than 20%");
        buyTax = newBuyTax * 100;
        sellTax = newSellTax * 100;
        burnRate = newBurnRate * 100;
    }

    function burn(uint256 amount) external {
        _burn(msg.sender, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        uint256 accountBalance = _balance[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balance[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(amount > 1e9, "Min transfer amt");
        //Update current _burnRate

        unchecked {
	    _transactionVolumeCurrent += amount;
            if (block.timestamp >= _lastBucketTime + _bucketDuration) {
                //If current > previous
                if (_transactionVolumeCurrent > _transactionVolumePrevious) {
                    if (burnRate + 50 <= 200) {
                        //Add 0.25% to _burnRate
                        burnRate += 50;
                    }
                    //else remain at 0 until volume decreases
                } else {
		    //If previous > current or previous == current
		    if (burnRate >= 50) {
                        //Remove 0.5% from _burnRate
                        burnRate -= 50;
                    }
                    
                }
                _transactionVolumePrevious = _transactionVolumeCurrent;
                _transactionVolumeCurrent = 0;
                _lastBucketTime = block.timestamp;
            }
        }
	
        uint256 _tax;
        if (_isExcludedFromFeeWallet[from] || _isExcludedFromFeeWallet[to]) {
            _tax = 0;
        } else {
            require(
                launch != 0 && amount <= maxTxAmount,
                "Launch / Max TxAmount 1% at launch"
            );

            if (inSwapAndLiquify == 1) {
                //No tax transfer
                _balance[from] -= amount;
                _balance[to] += amount;
                emit Transfer(from, to, amount);
                return;
            }

            if (from == uniswapV2Pair) {
                _tax = buyTax;
            } else if (to == uniswapV2Pair) {
                uint256 tokensToSwap = _balance[address(this)];
                if (tokensToSwap > minSwap && inSwapAndLiquify == 0) {
                    if (tokensToSwap > onePercent) {
                        tokensToSwap = onePercent;
                    }
                    inSwapAndLiquify = 1;
                    address[] memory path = new address[](2);
                    path[0] = address(this);
                    path[1] = WETH;
                    uniswapV2Router
                        .swapExactTokensForETHSupportingFeeOnTransferTokens(
                            tokensToSwap,
                            0,
                            path,
                            marketingWallet,
                            block.timestamp
                        );
                    inSwapAndLiquify = 0;
                }
                _tax = sellTax;
            } else {
                _tax = 0;
            }
        }


        if (_tax != 0) {
            uint256 burnTokens = amount * burnRate / 10000;
            uint256 taxTokens = amount * _tax / 10000;
            uint256 transferAmount = amount - (burnTokens + taxTokens);

            _balance[from] -= amount;
            _balance[to] += transferAmount;
            _balance[address(this)] += taxTokens;
            _totalSupply -= burnTokens;
            emit Transfer(from, address(0), burnTokens);
            emit Transfer(from, address(this), taxTokens);
            emit Transfer(from, to, transferAmount);
        } else {
            //No tax transfer
            _balance[from] -= amount;
            _balance[to] += amount;

            emit Transfer(from, to, amount);
        }
    }

    receive() external payable {}
}