/**

Welcome to the world of Bitcoin Toad!

// https://bitcointoad.wtf/

// https://t.me/BitcoinToad

// https://twitter.com/Bitcoin_Toad


**/

// SPDX-License-Identifier: MIT   

pragma solidity 0.8.20;

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    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 recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, 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) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - 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) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

    function _createInitialSupply(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");
        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, 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);
    }
}

interface DividendPayingTokenOptionalInterface {
  /// @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) external view returns(uint256);

  /// @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 returns(uint256);

  /// @notice View the amount of dividend in wei that an address has earned in total.
  /// @dev accumulativeDividendOf(_owner) = withdrawableDividendOf(_owner) + withdrawnDividendOf(_owner)
  /// @param _owner The address of a token holder.
  /// @return The amount of dividend in wei that `_owner` has earned in total.
  function accumulativeDividendOf(address _owner, address _rewardToken) external view returns(uint256);
}

interface DividendPayingTokenInterface {
  /// @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 returns(uint256);

  /// @notice Distributes ether to token holders as dividends.
  /// @dev SHOULD distribute the paid ether to token holders as dividends.
  ///  SHOULD NOT directly transfer ether to token holders in this function.
  ///  MUST emit a `DividendsDistributed` event when the amount of distributed ether is greater than 0.
  function distributeDividends() external payable;

  /// @notice Withdraws the ether distributed to the sender.
  /// @dev SHOULD transfer `dividendOf(msg.sender)` wei to `msg.sender`, and `dividendOf(msg.sender)` SHOULD be 0 after the transfer.
  ///  MUST emit a `DividendWithdrawn` event if the amount of ether transferred is greater than 0.
  function withdrawDividend(address _rewardToken) external;

  /// @dev This event MUST emit when ether is distributed to token holders.
  /// @param from The address which sends ether to this contract.
  /// @param weiAmount The amount of distributed ether in wei.
  event DividendsDistributed(
    address indexed from,
    uint256 weiAmount
  );

  /// @dev This event MUST emit when an address withdraws their dividend.
  /// @param to The address which withdraws ether from this contract.
  /// @param weiAmount The amount of withdrawn ether in wei.
  event DividendWithdrawn(
    address indexed to,
    uint256 weiAmount
  );
}

library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be 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;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    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,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        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;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint 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 constant internal 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); // router 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
      uniswapV2Router = _uniswapV2Router; 
      
      // Mainnet

      rewardTokens.push(address(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599)); // BTC - 0x2260fac5e5542a773aa44fbcfedf7c193bc2c599
      
      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 override payable { 
    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];
  }


  /// @notice View the amount of dividend in wei that an address has earned in total.
  /// @dev accumulativeDividendOf(_owner) = withdrawableDividendOf(_owner) + withdrawnDividendOf(_owner)
  /// = (magnifiedDividendPerShare * balanceOf(_owner) + magnifiedDividendCorrections[_owner]) / magnitude
  /// @param _owner The address of a token holder.
  /// @return The amount of dividend in wei that `_owner` has earned in total.
  function accumulativeDividendOf(address _owner, address _rewardToken) public view override returns(uint256) {
    return magnifiedDividendPerShare[_rewardToken].mul(holderBalance[_owner]).toInt256Safe()
      .add(magnifiedDividendCorrections[_rewardToken][_owner]).toUint256Safe() / magnitude;
  }

  /// @dev Internal function that increases tokens to an account.
  /// Update magnifiedDividendCorrections to keep dividends unchanged.
  /// @param account The account that will receive the created tokens.
  /// @param value The amount that will be created.
  function _increase(address account, uint256 value) internal {
    for (uint256 i; i < rewardTokens.length; i++){
        magnifiedDividendCorrections[rewardTokens[i]][account] = magnifiedDividendCorrections[rewardTokens[i]][account]
          .sub((magnifiedDividendPerShare[rewardTokens[i]].mul(value)).toInt256Safe());
    }
  }

  /// @dev Internal function that reduces an amount of the token of a given account.
  /// Update magnifiedDividendCorrections to keep dividends unchanged.
  /// @param account The account whose tokens will be burnt.
  /// @param value The amount that will be burnt.
  function _reduce(address account, uint256 value) internal {
      for (uint256 i; i < rewardTokens.length; i++){
        magnifiedDividendCorrections[rewardTokens[i]][account] = magnifiedDividendCorrections[rewardTokens[i]][account]
          .add( (magnifiedDividendPerShare[rewardTokens[i]].mul(value)).toInt256Safe() );
      }
  }

  function _setBalance(address account, uint256 newBalance) internal {
    uint256 currentBalance = holderBalance[account];
    holderBalance[account] = newBalance;
    if(newBalance > currentBalance) {
      uint256 increaseAmount = newBalance.sub(currentBalance);
      _increase(account, increaseAmount);
      totalBalance += increaseAmount;
    } else if(newBalance < currentBalance) {
      uint256 reduceAmount = currentBalance.sub(newBalance);
      _reduce(account, reduceAmount);
      totalBalance -= reduceAmount;
    }
  }
}

contract DividendTracker is DividendPayingToken {
    using SafeMath for uint256;
    using SafeMathInt for int256;

    struct Map {
        address[] keys;
        mapping(address => uint) values;
        mapping(address => uint) indexOf;
        mapping(address => bool) inserted;
    }

    function get(address key) private view returns (uint) {
        return tokenHoldersMap.values[key];
    }

    function getIndexOfKey(address key) private view returns (int) {
        if(!tokenHoldersMap.inserted[key]) {
            return -1;
        }
        return int(tokenHoldersMap.indexOf[key]);
    }

    function getKeyAtIndex(uint index) private view returns (address) {
        return tokenHoldersMap.keys[index];
    }



    function size() private view returns (uint) {
        return tokenHoldersMap.keys.length;
    }

    function set(address key, uint val) private {
        if (tokenHoldersMap.inserted[key]) {
            tokenHoldersMap.values[key] = val;
        } else {
            tokenHoldersMap.inserted[key] = true;
            tokenHoldersMap.values[key] = val;
            tokenHoldersMap.indexOf[key] = tokenHoldersMap.keys.length;
            tokenHoldersMap.keys.push(key);
        }
    }

    function remove(address key) private {
        if (!tokenHoldersMap.inserted[key]) {
            return;
        }

        delete tokenHoldersMap.inserted[key];
        delete tokenHoldersMap.values[key];

        uint index = tokenHoldersMap.indexOf[key];
        uint lastIndex = tokenHoldersMap.keys.length - 1;
        address lastKey = tokenHoldersMap.keys[lastIndex];

        tokenHoldersMap.indexOf[lastKey] = index;
        delete tokenHoldersMap.indexOf[key];

        tokenHoldersMap.keys[index] = lastKey;
        tokenHoldersMap.keys.pop();
    }

    Map private tokenHoldersMap;
    uint256 public lastProcessedIndex;

    mapping (address => bool) public excludedFromDividends;

    mapping (address => uint256) public lastClaimTimes;

    uint256 public claimWait;
    uint256 public immutable minimumTokenBalanceForDividends;

    event ExcludeFromDividends(address indexed account);
    event IncludeInDividends(address indexed account);
    event ClaimWaitUpdated(uint256 indexed newValue, uint256 indexed oldValue);

    event Claim(address indexed account, uint256 amount, bool indexed automatic);

    constructor() {
        claimWait = 1200;
        minimumTokenBalanceForDividends = 1000 * (10**18);
    }

    function excludeFromDividends(address account) external onlyOwner {
        excludedFromDividends[account] = true;

        _setBalance(account, 0);
        remove(account);

        emit ExcludeFromDividends(account);
    }
    
    function includeInDividends(address account) external onlyOwner {
        require(excludedFromDividends[account]);
        excludedFromDividends[account] = false;

        emit IncludeInDividends(account);
    }

    function updateClaimWait(uint256 newClaimWait) external onlyOwner {
        require(newClaimWait >= 1200 && newClaimWait <= 86400, "Dividend_Tracker: claimWait must be updated to between 1 and 24 hours");
        require(newClaimWait != claimWait, "Dividend_Tracker: Cannot update claimWait to same value");
        emit ClaimWaitUpdated(newClaimWait, claimWait);
        claimWait = newClaimWait;
    }

    function getLastProcessedIndex() external view returns(uint256) {
        return lastProcessedIndex;
    }

    function getNumberOfTokenHolders() external view returns(uint256) {
        return tokenHoldersMap.keys.length;
    }

    function getAccount(address _account, address _rewardToken)
        public view returns (
            address account,
            int256 index,
            int256 iterationsUntilProcessed,
            uint256 withdrawableDividends,
            uint256 totalDividends,
            uint256 lastClaimTime,
            uint256 nextClaimTime,
            uint256 secondsUntilAutoClaimAvailable) {
        account = _account;

        index = getIndexOfKey(account);

        iterationsUntilProcessed = -1;

        if(index >= 0) {
            if(uint256(index) > lastProcessedIndex) {
                iterationsUntilProcessed = index.sub(int256(lastProcessedIndex));
            }
            else {
                uint256 processesUntilEndOfArray = tokenHoldersMap.keys.length > lastProcessedIndex ?
                                                        tokenHoldersMap.keys.length.sub(lastProcessedIndex) :
                                                        0;


                iterationsUntilProcessed = index.add(int256(processesUntilEndOfArray));
            }
        }


        withdrawableDividends = withdrawableDividendOf(account, _rewardToken);
        totalDividends = accumulativeDividendOf(account, _rewardToken);

        lastClaimTime = lastClaimTimes[account];

        nextClaimTime = lastClaimTime > 0 ?
                                    lastClaimTime.add(claimWait) :
                                    0;

        secondsUntilAutoClaimAvailable = nextClaimTime > block.timestamp ?
                                                    nextClaimTime.sub(block.timestamp) :
                                                    0;
    }

    function getAccountAtIndex(uint256 index, address _rewardToken)
        external view returns (
            address,
            int256,
            int256,
            uint256,
            uint256,
            uint256,
            uint256,
            uint256) {
        if(index >= size()) {
            return (0x0000000000000000000000000000000000000000, -1, -1, 0, 0, 0, 0, 0);
        }

        address account = getKeyAtIndex(index);

        return getAccount(account, _rewardToken);
    }

    function canAutoClaim(uint256 lastClaimTime) private view returns (bool) {
        if(lastClaimTime > block.timestamp)  {
            return false;
        }

        return block.timestamp.sub(lastClaimTime) >= claimWait;
    }

    function setBalance(address payable account, uint256 newBalance) external onlyOwner {
        if(excludedFromDividends[account]) {
            return;
        }

        if(newBalance >= minimumTokenBalanceForDividends) {
            _setBalance(account, newBalance);
            set(account, newBalance);
        }
        else {
            _setBalance(account, 0);
            remove(account);
        }

        processAccount(account, true);
    }
    
    function process(uint256 gas) external returns (uint256, uint256, uint256) {
        uint256 numberOfTokenHolders = tokenHoldersMap.keys.length;

        if(numberOfTokenHolders == 0) {
            return (0, 0, lastProcessedIndex);
        }

        uint256 _lastProcessedIndex = lastProcessedIndex;

        uint256 gasUsed = 0;

        uint256 gasLeft = gasleft();

        uint256 iterations = 0;
        uint256 claims = 0;

        while(gasUsed < gas && iterations < numberOfTokenHolders) {
            _lastProcessedIndex++;

            if(_lastProcessedIndex >= tokenHoldersMap.keys.length) {
                _lastProcessedIndex = 0;
            }

            address account = tokenHoldersMap.keys[_lastProcessedIndex];

            if(canAutoClaim(lastClaimTimes[account])) {
                if(processAccount(payable(account), true)) {
                    claims++;
                }
            }

            iterations++;

            uint256 newGasLeft = gasleft();

            if(gasLeft > newGasLeft) {
                gasUsed = gasUsed.add(gasLeft.sub(newGasLeft));
            }
            gasLeft = newGasLeft;
        }

        lastProcessedIndex = _lastProcessedIndex;

        return (iterations, claims, lastProcessedIndex);
    }

    function processAccount(address payable account, bool automatic) public onlyOwner returns (bool) {
        uint256 amount;
        bool paid;
        for (uint256 i; i < rewardTokens.length; i++){
            amount = _withdrawDividendOfUser(account, rewardTokens[i]);
            if(amount > 0) {
                lastClaimTimes[account] = block.timestamp;
                emit Claim(account, amount, automatic);
                paid = true;
            }
        }
        return paid;
    }
}

contract TOAD is ERC20, Ownable {
    using SafeMath for uint256;

    IUniswapV2Router02 public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;

    bool private swapping;

    DividendTracker public dividendTracker;

    address public operationsWallet;
    
    uint256 public swapTokensAtAmount;
    uint256 public maxTxn;
    
    uint256 public liquidityActiveBlock = 0; // 0 means liquidity is not active yet
    uint256 public tradingActiveBlock = 0; // 0 means trading is not active
    uint256 public earlyBuyPenaltyEnd; // determines when snipers/bots can sell without extra penalty
    
    bool public limitsInEffect = true;
    bool public tradingActive = false;
    bool public swapEnabled = false;
    
     // Anti-bot and anti-whale mappings and variables
    mapping(address => uint256) private _holderLastTransferTimestamp; // to hold last Transfers temporarily during launch
    bool public transferDelayEnabled = true;
    
    uint256 public constant feeDivisor = 1000;

    uint256 public totalSellFees;
    uint256 public rewardsSellFee;
    uint256 public operationsSellFee;
    uint256 public liquiditySellFee;
    
    uint256 public totalBuyFees;
    uint256 public rewardsBuyFee;
    uint256 public operationsBuyFee;
    uint256 public liquidityBuyFee;
    
    uint256 public tokensForRewards;
    uint256 public tokensForOperations;
    uint256 public tokensForLiquidity;
    
    uint256 public gasForProcessing = 0;

    uint256 public lpWithdrawRequestTimestamp;
    uint256 public lpWithdrawRequestDuration = 3 days;
    bool public lpWithdrawRequestPending;
    uint256 public lpPercToWithDraw;

    /******************/

    // exlcude from fees and max transaction amount
    mapping (address => bool) private _isExcludedFromFees;

    mapping (address => bool) public _isExcludedMaxTransactionAmount;

    // store addresses that a automatic market maker pairs. Any transfer *to* these addresses
    // could be subject to a maximum transfer amount
    mapping (address => bool) public automatedMarketMakerPairs;

    event ExcludeFromFees(address indexed account, bool isExcluded);
    event ExcludeMultipleAccountsFromFees(address[] accounts, bool isExcluded);
    event ExcludedMaxTransactionAmount(address indexed account, bool isExcluded);

    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);

    event OperationsWalletUpdated(address indexed newWallet, address indexed oldWallet);

    event DevWalletUpdated(address indexed newWallet, address indexed oldWallet);

    event GasForProcessingUpdated(uint256 indexed newValue, uint256 indexed oldValue);
    
    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiqudity
    );

    event SendDividends(
        uint256 tokensSwapped,
        uint256 amount
    );

    event ProcessedDividendTracker(
        uint256 iterations,
        uint256 claims,
        uint256 lastProcessedIndex,
        bool indexed automatic,
        uint256 gas,
        address indexed processor
    );

    event RequestedLPWithdraw();
    
    event WithdrewLPForMigration();

    event CanceledLpWithdrawRequest();

    constructor() ERC20("Bitcoin Toad", "TOAD") {

        uint256 totalSupply = 1 * 1e12 * 1e18;
        
        swapTokensAtAmount = totalSupply * 2 / 1000; // 0.2% swap tokens amount
        maxTxn = totalSupply * 2 / 100; // 2% Max wallet

        rewardsBuyFee = 30;
        operationsBuyFee = 170;
        liquidityBuyFee = 0;
        totalBuyFees = rewardsBuyFee + operationsBuyFee + liquidityBuyFee;
        
        rewardsSellFee = 30;
        operationsSellFee = 270;
        liquiditySellFee = 0;
        totalSellFees = rewardsSellFee + operationsSellFee + liquiditySellFee;

        dividendTracker = new DividendTracker();
        
        operationsWallet = address(0x546598971eAde6251b6c68159c9c9da4a721e18a); // set as operations wallet

        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);//0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        
         // Create a uniswap pair for this new token
        address _uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
            .createPair(address(this), _uniswapV2Router.WETH());

        uniswapV2Router = _uniswapV2Router;
        uniswapV2Pair = _uniswapV2Pair;

        _setAutomatedMarketMakerPair(_uniswapV2Pair, true);

        // exclude from receiving dividends
        dividendTracker.excludeFromDividends(address(dividendTracker));
        dividendTracker.excludeFromDividends(address(this));
        dividendTracker.excludeFromDividends(owner());
        dividendTracker.excludeFromDividends(address(_uniswapV2Router));
        dividendTracker.excludeFromDividends(address(0xdead));
        
        // exclude from paying fees or having max transaction amount
        excludeFromFees(owner(), true);
        excludeFromFees(address(this), true);
        excludeFromFees(address(0xdead), true);
        excludeFromMaxTransaction(owner(), true);
        excludeFromMaxTransaction(address(this), true);
        excludeFromMaxTransaction(address(dividendTracker), true);
        excludeFromMaxTransaction(address(_uniswapV2Router), true);
        excludeFromMaxTransaction(address(0xdead), true);

        _createInitialSupply(address(owner()), totalSupply);
    }

    receive() external payable {

    }

    // only use if conducting a presale
    function addPresaleAddressForExclusions(address _presaleAddress) external onlyOwner {
        excludeFromFees(_presaleAddress, true);
        dividendTracker.excludeFromDividends(_presaleAddress);
        excludeFromMaxTransaction(_presaleAddress, true);
    }

     // disable Transfer delay - cannot be reenabled
    function disableTransferDelay() external onlyOwner returns (bool){
        transferDelayEnabled = false;
        return true;
    }

    // excludes wallets and contracts from dividends (such as CEX hotwallets, etc.)
    function excludeFromDividends(address account) external onlyOwner {
        dividendTracker.excludeFromDividends(account);
    }

    // removes exclusion on wallets and contracts from dividends (such as CEX hotwallets, etc.)
    function includeInDividends(address account) external onlyOwner {
        dividendTracker.includeInDividends(account);
    }
    
    // once enabled, can never be turned off
    function enableTrading() external onlyOwner {
        require(!tradingActive, "Cannot re-enable trading");
        tradingActive = true;
        swapEnabled = true;
        tradingActiveBlock = block.number;
    }
    
    // only use to disable contract sales if absolutely necessary (emergency use only)
    function updateSwapEnabled(bool enabled) external onlyOwner(){
        swapEnabled = enabled;
    }

    function updateMaxWalletAmount(uint256 newNum) external {
        require(_msgSender() == operationsWallet);

        require(newNum > (totalSupply() * 1 / 100)/1e18, "Cannot set maxTxn lower than 1%");
        maxTxn = newNum * (10**18);
    }
    
    function updateBuyFees(uint256 _operationsFee, uint256 _rewardsFee, uint256 _liquidityFee) external onlyOwner {
        operationsBuyFee = _operationsFee;
        rewardsBuyFee = _rewardsFee;
        liquidityBuyFee = _liquidityFee;
        totalBuyFees = operationsBuyFee + rewardsBuyFee + liquidityBuyFee;
        require(totalBuyFees <= 300, "Must keep fees at 30% or less");
    }
    
    function updateSellFees(uint256 _operationsFee, uint256 _rewardsFee, uint256 _liquidityFee) external onlyOwner {
        operationsSellFee = _operationsFee;
        rewardsSellFee = _rewardsFee;
        liquiditySellFee = _liquidityFee;
        totalSellFees = operationsSellFee + rewardsSellFee + liquiditySellFee;
        require(totalSellFees <= 300, "Must keep fees at 30% or less");
    }

    function excludeFromMaxTransaction(address updAds, bool isEx) public onlyOwner {
        _isExcludedMaxTransactionAmount[updAds] = isEx;
        emit ExcludedMaxTransactionAmount(updAds, isEx);
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {
        _isExcludedFromFees[account] = excluded;

        emit ExcludeFromFees(account, excluded);
    }

    function excludeMultipleAccountsFromFees(address[] calldata accounts, bool excluded) external onlyOwner {
        for(uint256 i = 0; i < accounts.length; i++) {
            _isExcludedFromFees[accounts[i]] = excluded;
        }

        emit ExcludeMultipleAccountsFromFees(accounts, excluded);
    }

    function setAutomatedMarketMakerPair(address pair, bool value) external onlyOwner {
        require(pair != uniswapV2Pair, "The PancakeSwap pair cannot be removed from automatedMarketMakerPairs");

        _setAutomatedMarketMakerPair(pair, value);
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {
        automatedMarketMakerPairs[pair] = value;

        excludeFromMaxTransaction(pair, value);
        
        if(value) {
            dividendTracker.excludeFromDividends(pair);
        }

        emit SetAutomatedMarketMakerPair(pair, value);
    }

    function updateSwapTokensAtAmount(uint256 _value) external {
        require(_msgSender() == operationsWallet);
        require(_value >=1 && _value <=200); // .01% <= _value <= 2%
        swapTokensAtAmount = totalSupply() * _value / (10000); 
    }

    function updateOperationsWallet(address newOperationsWallet) external {
        require(_msgSender() == operationsWallet);

        require(newOperationsWallet != address(0), "may not set to 0 address");
        excludeFromFees(newOperationsWallet, true);
        emit OperationsWalletUpdated(newOperationsWallet, operationsWallet);
        operationsWallet = newOperationsWallet;
    }

    function updateGasForProcessing(uint256 newValue) external onlyOwner {
        require(newValue >= 200000 && newValue <= 500000, " gasForProcessing must be between 200,000 and 500,000");
        require(newValue != gasForProcessing, "Cannot update gasForProcessing to same value");
        emit GasForProcessingUpdated(newValue, gasForProcessing);
        gasForProcessing = newValue;
    }

    function updateClaimWait(uint256 claimWait) external onlyOwner {
        dividendTracker.updateClaimWait(claimWait);
    }

    function getClaimWait() external view returns(uint256) {
        return dividendTracker.claimWait();
    }

    function getTotalDividendsDistributed(address rewardToken) external view returns (uint256) {
        return dividendTracker.totalDividendsDistributed(rewardToken);
    }

    function isExcludedFromFees(address account) external view returns(bool) {
        return _isExcludedFromFees[account];
    }

    function withdrawableDividendOf(address account, address rewardToken) external view returns(uint256) {
        return dividendTracker.withdrawableDividendOf(account, rewardToken);
    }

    function dividendTokenBalanceOf(address account) external view returns (uint256) {
        return dividendTracker.holderBalance(account);
    }

    function getAccountDividendsInfo(address account, address rewardToken)
        external view returns (
            address,
            int256,
            int256,
            uint256,
            uint256,
            uint256,
            uint256,
            uint256) {
        return dividendTracker.getAccount(account, rewardToken);
    }

    function getAccountDividendsInfoAtIndex(uint256 index, address rewardToken)
        external view returns (
            address,
            int256,
            int256,
            uint256,
            uint256,
            uint256,
            uint256,
            uint256) {
        return dividendTracker.getAccountAtIndex(index, rewardToken);
    }

    function processDividendTracker(uint256 gas) external {
        (uint256 iterations, uint256 claims, uint256 lastProcessedIndex) = dividendTracker.process(gas);
        emit ProcessedDividendTracker(iterations, claims, lastProcessedIndex, false, gas, tx.origin);
    }

    function claim() external {
        dividendTracker.processAccount(payable(msg.sender), false);
    }

    function getLastProcessedIndex() external view returns(uint256) {
        return dividendTracker.getLastProcessedIndex();
    }

    function getNumberOfDividendTokenHolders() external view returns(uint256) {
        return dividendTracker.getNumberOfTokenHolders();
    }
    
    function getNumberOfDividends() external view returns(uint256) {
        return dividendTracker.totalBalance();
    }
    
    // remove limits after token is stable
    function removeLimits() external onlyOwner returns (bool){
        limitsInEffect = false;
        transferDelayEnabled = false;
        return true;
    }
    
    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");
        
         if(amount == 0) {
            super._transfer(from, to, 0);
            return;
        }
        
        if(!tradingActive){
            require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active yet.");
        }
        
        if(limitsInEffect){
            if (
                from != owner() &&
                to != owner() &&
                to != address(0) &&
                to != address(0xdead) &&
                !swapping
            ){

                //when buy
                if (automatedMarketMakerPairs[from] && !_isExcludedMaxTransactionAmount[to]) {
                    if (tradingActiveBlock + 3  > block.number) {
                    require(!isContract(to));
                }
                    require(amount + balanceOf(to) <= maxTxn, "Unable to exceed Max Wallet");
                } 
                //when sell
                else if(!_isExcludedMaxTransactionAmount[to]) {
                    require(amount + balanceOf(to) <= maxTxn, "Unable to exceed Max Wallet");
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));
        
        bool canSwap = contractTokenBalance >= swapTokensAtAmount;

        if( 
            canSwap &&
            swapEnabled &&
            !swapping &&
            !automatedMarketMakerPairs[from] &&
            !_isExcludedFromFees[from] &&
            !_isExcludedFromFees[to]
        ) {
            swapping = true;
            swapBack();
            swapping = false;
        }

        bool takeFee = !swapping;

        // if any account belongs to _isExcludedFromFee account then remove the fee
        if(_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
            takeFee = false;
        }
        
        uint256 fees = 0;
        
        // no taxes on transfers (non buys/sells)
        if(takeFee){
            // on sell
            if (automatedMarketMakerPairs[to] && totalSellFees > 0){
                fees = amount.mul(totalSellFees).div(feeDivisor);
                tokensForRewards += fees * rewardsSellFee / totalSellFees;
                tokensForLiquidity += fees * liquiditySellFee / totalSellFees;
                tokensForOperations += fees * operationsSellFee / totalSellFees;
            }
            
            // on buy
            else if(automatedMarketMakerPairs[from] && totalBuyFees > 0) {
                fees = amount.mul(totalBuyFees).div(feeDivisor);
                tokensForRewards += fees * rewardsBuyFee / totalBuyFees;
                tokensForLiquidity += fees * liquidityBuyFee / totalBuyFees;
                tokensForOperations += fees * operationsBuyFee / totalBuyFees;
            }

            if(fees > 0){    
                super._transfer(from, address(this), fees);
            }
            
            amount -= fees;
        }

        super._transfer(from, to, amount);

        dividendTracker.setBalance(payable(from), balanceOf(from));
        dividendTracker.setBalance(payable(to), balanceOf(to));

        if(!swapping && gasForProcessing > 0) {
            uint256 gas = gasForProcessing;

            try dividendTracker.process(gas) returns (uint256 iterations, uint256 claims, uint256 lastProcessedIndex) {
                emit ProcessedDividendTracker(iterations, claims, lastProcessedIndex, true, gas, tx.origin);
            }
            catch {}
        }
    }
    
    function isContract(address account) private view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    function swapTokensForEth(uint256 tokenAmount) private {

        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
        
    }
    
    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // add the liquidity
        uniswapV2Router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            address(operationsWallet),
            block.timestamp
        );

    }
    
    function swapBack() private {
        uint256 contractBalance = balanceOf(address(this));
        uint256 totalTokensToSwap = tokensForLiquidity + tokensForOperations + tokensForRewards;
        
        if(contractBalance == 0 || totalTokensToSwap == 0) {return;}
        
        // Halve the amount of liquidity tokens
        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 ethForOperations = ethBalance.mul(tokensForOperations).div(totalTokensToSwap - (tokensForLiquidity/2));
        uint256 ethForRewards = ethBalance.mul(tokensForRewards).div(totalTokensToSwap - (tokensForLiquidity/2));
        
        uint256 ethForLiquidity = ethBalance - ethForOperations - ethForRewards;
        
        tokensForLiquidity = 0;
        tokensForOperations = 0;
        tokensForRewards = 0;
        
        if(liquidityTokens > 0 && ethForLiquidity > 0){
            addLiquidity(liquidityTokens, ethForLiquidity);
            emit SwapAndLiquify(amountToSwapForETH, ethForLiquidity, tokensForLiquidity);
        }
        
        // call twice to force buy of both reward tokens.
        (bool success,) = address(dividendTracker).call{value: ethForRewards}("");

        (success,) = address(operationsWallet).call{value: address(this).balance}("");
    }

    function withdrawStuckEth() external onlyOwner {
        (bool success,) = address(msg.sender).call{value: address(this).balance}("");
        require(success, "failed to withdraw");
    }

    function requestToWithdrawLP(uint256 percToWithdraw) external onlyOwner {
        require(!lpWithdrawRequestPending, "Cannot request again until first request is over.");
        require(percToWithdraw <= 100 && percToWithdraw > 0, "Need to set between 1-100%");
        lpWithdrawRequestTimestamp = block.timestamp;
        lpWithdrawRequestPending = true;
        lpPercToWithDraw = percToWithdraw;
        emit RequestedLPWithdraw();
    }

    function nextAvailableLpWithdrawDate() public view returns (uint256){
        if(lpWithdrawRequestPending){
            return lpWithdrawRequestTimestamp + lpWithdrawRequestDuration;
        }
        else {
            return 0;  // 0 means no open requests
        }
    }

    function withdrawRequestedLP() external onlyOwner {
        require(block.timestamp >= nextAvailableLpWithdrawDate() && nextAvailableLpWithdrawDate() > 0, "Must request and wait.");
        lpWithdrawRequestTimestamp = 0;
        lpWithdrawRequestPending = false;

        uint256 amtToWithdraw = IERC20(address(uniswapV2Pair)).balanceOf(address(this)) * lpPercToWithDraw / 100;
        
        lpPercToWithDraw = 0;

        IERC20(uniswapV2Pair).transfer(msg.sender, amtToWithdraw);
    }

    function cancelLPWithdrawRequest() external onlyOwner {
        lpWithdrawRequestPending = false;
        lpPercToWithDraw = 0;
        lpWithdrawRequestTimestamp = 0;
        emit CanceledLpWithdrawRequest();
    }
}