// Contract: DogeBonk
// Target function: function accumulativeDividendOf(address _owner, address _rewardToken)
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

library SafeMathInt {
    int256 private constant MIN_INT256 = int256(1) << 255;
    int256 private constant MAX_INT256 = ~(int256(1) << 255);

    /**
     * @dev Multiplies two int256 variables and fails on overflow.
     */
    function mul(int256 a, int256 b) internal pure returns (int256) {
        int256 c = a * b;

        // Detect overflow when multiplying MIN_INT256 with -1
        require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
        require((b == 0) || (c / b == a));
        return c;
    }

    /**
     * @dev Division of two int256 variables and fails on overflow.
     */
    function div(int256 a, int256 b) internal pure returns (int256) {
        // Prevent overflow when dividing MIN_INT256 by -1
        require(b != -1 || a != MIN_INT256);

        // Solidity already throws when dividing by 0.
        return a / b;
    }

    /**
     * @dev Subtracts two int256 variables and fails on overflow.
     */
    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;
    }

    /**
     * @dev Adds two int256 variables and fails on overflow.
     */
    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;
    }

    /**
     * @dev Converts to absolute value, and fails on overflow.
     */
    function abs(int256 a) internal pure returns (int256) {
        require(a != MIN_INT256);
        return a < 0 ? -a : a;
    }

    function toUint256Safe(int256 a) internal pure returns (uint256) {
        require(a >= 0);
        return uint256(a);
    }
}

library SafeMathUint {
    function toInt256Safe(uint256 a) internal pure returns (int256) {
        int256 b = int256(a);
        require(b >= 0);
        return b;
    }
}

interface IUniswapV2Router01 {
    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 removeLiquidity(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETH(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountToken, uint256 amountETH);

    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint256 liquidity,
        uint256 amountAMin,
        uint256 amountBMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountA, uint256 amountB);

    function removeLiquidityETHWithPermit(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountToken, uint256 amountETH);

    function swapExactTokensForTokens(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapTokensForExactTokens(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactETHForTokens(
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function swapTokensForExactETH(
        uint256 amountOut,
        uint256 amountInMax,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapExactTokensForETH(
        uint256 amountIn,
        uint256 amountOutMin,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external returns (uint256[] memory amounts);

    function swapETHForExactTokens(
        uint256 amountOut,
        address[] calldata path,
        address to,
        uint256 deadline
    ) external payable returns (uint256[] memory amounts);

    function quote(
        uint256 amountA,
        uint256 reserveA,
        uint256 reserveB
    ) external pure returns (uint256 amountB);

    function getAmountOut(
        uint256 amountIn,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountOut);

    function getAmountIn(
        uint256 amountOut,
        uint256 reserveIn,
        uint256 reserveOut
    ) external pure returns (uint256 amountIn);

    function getAmountsOut(uint256 amountIn, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);

    function getAmountsIn(uint256 amountOut, address[] calldata path)
        external
        view
        returns (uint256[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external returns (uint256 amountETH);

    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint256 liquidity,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline,
        bool approveMax,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external returns (uint256 amountETH);

    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 DividendPayingToken is
    DividendPayingTokenInterface,
    DividendPayingTokenOptionalInterface,
    Ownable
{
    using SafeMath for uint256;
    using SafeMathUint for uint256;
    using SafeMathInt for int256;

    // With `magnitude`, we can properly distribute dividends even if the amount of received ether is small.
    // For more discussion about choosing the value of `magnitude`,
    //  see https://github.com/ethereum/EIPs/issues/1726#issuecomment-472352728
    uint256 internal constant magnitude = 2**128;

    mapping(address => uint256) internal magnifiedDividendPerShare;
    address[] public rewardTokens;
    address public nextRewardToken;
    uint256 public rewardTokenCounter;

    IUniswapV2Router02 public immutable uniswapV2Router;

    // About dividendCorrection:
    // If the token balance of a `_user` is never changed, the dividend of `_user` can be computed with:
    //   `dividendOf(_user) = dividendPerShare * balanceOf(_user)`.
    // When `balanceOf(_user)` is changed (via minting/burning/transferring tokens),
    //   `dividendOf(_user)` should not be changed,
    //   but the computed value of `dividendPerShare * balanceOf(_user)` is changed.
    // To keep the `dividendOf(_user)` unchanged, we add a correction term:
    //   `dividendOf(_user) = dividendPerShare * balanceOf(_user) + dividendCorrectionOf(_user)`,
    //   where `dividendCorrectionOf(_user)` is updated whenever `balanceOf(_user)` is changed:
    //   `dividendCorrectionOf(_user) = dividendPerShare * (old balanceOf(_user)) - (new balanceOf(_user))`.
    // So now `dividendOf(_user)` returns the same value before and after `balanceOf(_user)` is changed.
    mapping(address => mapping(address => int256))
        internal magnifiedDividendCorrections;
    mapping(address => mapping(address => uint256)) internal withdrawnDividends;

    mapping(address => uint256) public holderBalance;
    uint256 public totalBalance;

    mapping(address => uint256) public totalDividendsDistributed;

    constructor() {
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        );
        uniswapV2Router = _uniswapV2Router;

        // Mainnet

        rewardTokens.push(address(0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84));
        nextRewardToken = rewardTokens[0];
    }

    /// @dev Distributes dividends whenever ether is paid to this contract.
    receive() external payable {
        distributeDividends();
    }

    /// @notice Distributes ether to token holders as dividends.
    /// @dev It reverts if the total supply of tokens is 0.
    /// It emits the `DividendsDistributed` event if the amount of received ether is greater than 0.
    /// About undistributed ether:
    ///   In each distribution, there is a small amount of ether not distributed,
    ///     the magnified amount of which is
    ///     `(msg.value * magnitude) % totalSupply()`.
    ///   With a well-chosen `magnitude`, the amount of undistributed ether
    ///     (de-magnified) in a distribution can be less than 1 wei.
    ///   We can actually keep track of the undistributed ether in a distribution
    ///     and try to distribute it in the next distribution,
    ///     but keeping track of such data on-chain costs much more than
    ///     the saved ether, so we don't do that.

    function distributeDividends() public payable override {
        require(totalBalance > 0);
        uint256 initialBalance = IERC20(nextRewardToken).balanceOf(
            address(this)
        );
        buyTokens(msg.value, nextRewardToken);
        uint256 newBalance = IERC20(nextRewardToken)
            .balanceOf(address(this))
            .sub(initialBalance);
        if (newBalance > 0) {
            magnifiedDividendPerShare[
                nextRewardToken
            ] = magnifiedDividendPerShare[nextRewardToken].add(
                (newBalance).mul(magnitude) / totalBalance
            );
            emit DividendsDistributed(msg.sender, newBalance);

            totalDividendsDistributed[
                nextRewardToken
            ] = totalDividendsDistributed[nextRewardToken].add(newBalance);
        }
        rewardTokenCounter = rewardTokenCounter == rewardTokens.length - 1
            ? 0
            : rewardTokenCounter + 1;
        nextRewardToken = rewardTokens[rewardTokenCounter];
    }

    // useful for buybacks or to reclaim any BNB on the contract in a way that helps holders.
    function buyTokens(uint256 bnbAmountInWei, address rewardToken) internal {
        // generate the uniswap pair path of weth -> eth
        address[] memory path = new address[](2);
        path[0] = uniswapV2Router.WETH();
        path[1] = rewardToken;

        // make the swap
        uniswapV2Router.swapExactETHForTokensSupportingFeeOnTransferTokens{
            value: bnbAmountInWei
        }(
            0, // accept any amount of Ethereum
            path,
            address(this),
            block.timestamp
        );
    }

    /// @notice Withdraws the ether distributed to the sender.
    /// @dev It emits a `DividendWithdrawn` event if the amount of withdrawn ether is greater than 0.
    function withdrawDividend(address _rewardToken) external virtual override {
        _withdrawDividendOfUser(payable(msg.sender), _rewardToken);
    }

    /// @notice Withdraws the ether distributed to the sender.
    /// @dev It emits a `DividendWithdrawn` event if the amount of withdrawn ether is greater than 0.
    function _withdrawDividendOfUser(address payable user, address _rewardToken)
        internal
        returns (uint256)
    {
        uint256 _withdrawableDividend = withdrawableDividendOf(
            user,
            _rewardToken
        );
        if (_withdrawableDividend > 0) {
            withdrawnDividends[user][_rewardToken] = withdrawnDividends[user][
                _rewardToken
            ].add(_withdrawableDividend);
            emit DividendWithdrawn(user, _withdrawableDividend);
            IERC20(_rewardToken).transfer(user, _withdrawableDividend);
            return _withdrawableDividend;
        }

        return 0;
    }

    /// @notice View the amount of dividend in wei that an address can withdraw.
    /// @param _owner The address of a token holder.
    /// @return The amount of dividend in wei that `_owner` can withdraw.
    function dividendOf(address _owner, address _rewardToken)
        external
        view
        override
        returns (uint256)
    {
        return withdrawableDividendOf(_owner, _rewardToken);
    }

    /// @notice View the amount of dividend in wei that an address can withdraw.
    /// @param _owner The address of a token holder.
    /// @return The amount of dividend in wei that `_owner` can withdraw.
    function withdrawableDividendOf(address _owner, address _rewardToken)
        public
        view
        override
        returns (uint256)
    {
        return
            accumulativeDividendOf(_owner, _rewardToken).sub(
                withdrawnDividends[_owner][_rewardToken]
            );
    }

    /// @notice View the amount of dividend in wei that an address has withdrawn.
    /// @param _owner The address of a token holder.
    /// @return The amount of dividend in wei that `_owner` has withdrawn.
    function withdrawnDividendOf(address _owner, address _rewardToken)
        external
        view
        override
        returns (uint256)
    {
        return withdrawnDividends[_owner][_rewardToken];
    }