/*
https://powerpool.finance/

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        rrp pr   wr00rrp      prwww0  pp   wr pp w00r prwwwpr  0rw    prwww0  pp   wr pp   wr    r0
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         prwr wrr0wpwr        00        www0   0w0ww    www0   0w     00        www0    www0   0www0
          wrr ww0rrrr

*/

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
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;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
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);
}

// File: @openzeppelin/contracts/utils/Address.sol

pragma solidity ^0.6.2;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol

pragma solidity ^0.6.0;




/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/GSN/Context.sol

pragma solidity ^0.6.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol

pragma solidity ^0.6.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
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 () internal {
        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;
    }
}

// File: contracts/interfaces/BMathInterface.sol

pragma solidity 0.6.12;

interface BMathInterface {
  function calcInGivenOut(
    uint256 tokenBalanceIn,
    uint256 tokenWeightIn,
    uint256 tokenBalanceOut,
    uint256 tokenWeightOut,
    uint256 tokenAmountOut,
    uint256 swapFee
  ) external pure returns (uint256 tokenAmountIn);
}

// File: contracts/interfaces/BPoolInterface.sol

pragma solidity 0.6.12;



interface BPoolInterface is IERC20, BMathInterface {
  function joinPool(uint256 poolAmountOut, uint256[] calldata maxAmountsIn) external;

  function exitPool(uint256 poolAmountIn, uint256[] calldata minAmountsOut) external;

  function swapExactAmountIn(
    address,
    uint256,
    address,
    uint256,
    uint256
  ) external returns (uint256, uint256);

  function swapExactAmountOut(
    address,
    uint256,
    address,
    uint256,
    uint256
  ) external returns (uint256, uint256);

  function joinswapExternAmountIn(
    address,
    uint256,
    uint256
  ) external returns (uint256);

  function joinswapPoolAmountOut(
    address,
    uint256,
    uint256
  ) external returns (uint256);

  function exitswapPoolAmountIn(
    address,
    uint256,
    uint256
  ) external returns (uint256);

  function exitswapExternAmountOut(
    address,
    uint256,
    uint256
  ) external returns (uint256);

  function getDenormalizedWeight(address) external view returns (uint256);

  function getBalance(address) external view returns (uint256);

  function getSwapFee() external view returns (uint256);

  function getTotalDenormalizedWeight() external view returns (uint256);

  function getCommunityFee()
    external
    view
    returns (
      uint256,
      uint256,
      uint256,
      address
    );

  function calcAmountWithCommunityFee(
    uint256,
    uint256,
    address
  ) external view returns (uint256, uint256);

  function getRestrictions() external view returns (address);

  function isPublicSwap() external view returns (bool);

  function isFinalized() external view returns (bool);

  function isBound(address t) external view returns (bool);

  function getCurrentTokens() external view returns (address[] memory tokens);

  function getFinalTokens() external view returns (address[] memory tokens);

  function setSwapFee(uint256) external;

  function setCommunityFeeAndReceiver(
    uint256,
    uint256,
    uint256,
    address
  ) external;

  function setController(address) external;

  function setPublicSwap(bool) external;

  function finalize() external;

  function bind(
    address,
    uint256,
    uint256
  ) external;

  function rebind(
    address,
    uint256,
    uint256
  ) external;

  function unbind(address) external;

  function callVoting(
    address voting,
    bytes4 signature,
    bytes calldata args,
    uint256 value
  ) external;

  function getMinWeight() external view returns (uint256);

  function getMaxBoundTokens() external view returns (uint256);
}

// File: contracts/interfaces/TokenInterface.sol

pragma solidity 0.6.12;


interface TokenInterface is IERC20 {
  function deposit() external payable;

  function withdraw(uint256) external;
}

// File: contracts/interfaces/IPoolRestrictions.sol

pragma solidity 0.6.12;

interface IPoolRestrictions {
  function getMaxTotalSupply(address _pool) external view returns (uint256);

  function isVotingSignatureAllowed(address _votingAddress, bytes4 _signature) external view returns (bool);

  function isVotingSenderAllowed(address _votingAddress, address _sender) external view returns (bool);

  function isWithoutFee(address _addr) external view returns (bool);
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
  event Approval(address indexed owner, address indexed spender, uint256 value);
  event Transfer(address indexed from, address indexed to, uint256 value);

  function name() external pure returns (string memory);

  function symbol() external pure returns (string memory);

  function decimals() external pure returns (uint8);

  function totalSupply() external view returns (uint256);

  function balanceOf(address owner) external view returns (uint256);

  function allowance(address owner, address spender) external view returns (uint256);

  function approve(address spender, uint256 value) external returns (bool);

  function transfer(address to, uint256 value) external returns (bool);

  function transferFrom(
    address from,
    address to,
    uint256 value
  ) external returns (bool);

  function DOMAIN_SEPARATOR() external view returns (bytes32);

  function PERMIT_TYPEHASH() external pure returns (bytes32);

  function nonces(address owner) external view returns (uint256);

  function permit(
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external;

  event Mint(address indexed sender, uint256 amount0, uint256 amount1);
  event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to);
  event Swap(
    address indexed sender,
    uint256 amount0In,
    uint256 amount1In,
    uint256 amount0Out,
    uint256 amount1Out,
    address indexed to
  );
  event Sync(uint112 reserve0, uint112 reserve1);

  function MINIMUM_LIQUIDITY() external pure returns (uint256);

  function factory() external view returns (address);

  function token0() external view returns (address);

  function token1() external view returns (address);

  function getReserves()
    external
    view
    returns (
      uint112 reserve0,
      uint112 reserve1,
      uint32 blockTimestampLast
    );

  function price0CumulativeLast() external view returns (uint256);

  function price1CumulativeLast() external view returns (uint256);

  function kLast() external view returns (uint256);

  function mint(address to) external returns (uint256 liquidity);

  function burn(address to) external returns (uint256 amount0, uint256 amount1);

  function swap(
    uint256 amount0Out,
    uint256 amount1Out,
    address to,
    bytes calldata data
  ) external;

  function skim(address to) external;

  function sync() external;

  function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
  event PairCreated(address indexed token0, address indexed token1, address pair, uint256);

  function feeTo() external view returns (address);

  function feeToSetter() external view returns (address);

  function migrator() external view returns (address);

  function getPair(address tokenA, address tokenB) external view returns (address pair);

  function allPairs(uint256) external view returns (address pair);

  function allPairsLength() external view returns (uint256);

  function createPair(address tokenA, address tokenB) external returns (address pair);

  function setFeeTo(address) external;

  function setFeeToSetter(address) external;

  function setMigrator(address) external;
}

// File: contracts/lib/SafeMathUniswap.sol

pragma solidity =0.6.12;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMathUniswap {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/lib/UniswapV2Library.sol

pragma solidity >=0.5.0;



library UniswapV2Library {
    using SafeMathUniswap for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'e18a34eb0e04b04f7a0ac29a6e80748dca96319b42c54d679cb821dca90c6303' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// File: contracts/EthPiptSwap.sol

pragma solidity 0.6.12;











contract EthPiptSwap is Ownable {
  using SafeMath for uint256;
  using SafeERC20 for IERC20;
  using SafeERC20 for TokenInterface;
  using SafeERC20 for BPoolInterface;

  TokenInterface public weth;
  TokenInterface public cvp;
  BPoolInterface public pipt;

  uint256[] public feeLevels;
  uint256[] public feeAmounts;
  address public feePayout;
  address public feeManager;

  mapping(address => bool) public uniswapFactoryAllowed;
  mapping(address => address) public uniswapEthPairByTokenAddress;
  mapping(address => bool) public reApproveTokens;
  uint256 public defaultSlippage;

  struct CalculationStruct {
    uint256 tokenAmount;
    uint256 ethAmount;
    uint256 tokenReserve;
    uint256 ethReserve;
  }

  event SetUniswapFactoryAllowed(address indexed factory, bool indexed allowed);
  event SetTokenSetting(address indexed token, bool indexed reApprove, address indexed uniswapPair);
  event SetDefaultSlippage(uint256 newDefaultSlippage);
  event SetFees(
    address indexed sender,
    uint256[] newFeeLevels,
    uint256[] newFeeAmounts,
    address indexed feePayout,
    address indexed feeManager
  );

  event EthToPiptSwap(
    address indexed user,
    uint256 ethInAmount,
    uint256 ethSwapFee,
    uint256 poolOutAmount,
    uint256 poolCommunityFee
  );
  event OddEth(address indexed user, uint256 amount);
  event PiptToEthSwap(
    address indexed user,
    uint256 poolInAmount,
    uint256 poolCommunityFee,
    uint256 ethOutAmount,
    uint256 ethSwapFee
  );
  event PayoutCVP(address indexed receiver, uint256 wethAmount, uint256 cvpAmount);

  constructor(
    address _weth,
    address _cvp,
    address _pipt,
    address _feeManager
  ) public Ownable() {
    weth = TokenInterface(_weth);
    cvp = TokenInterface(_cvp);
    pipt = BPoolInterface(_pipt);
    feeManager = _feeManager;
    defaultSlippage = 0.02 ether;
  }

  modifier onlyFeeManagerOrOwner() {
    require(msg.sender == feeManager || msg.sender == owner(), "NOT_FEE_MANAGER");
    _;
  }

  receive() external payable {
    if (msg.sender != tx.origin) {
      return;
    }
    swapEthToPipt(defaultSlippage);
  }

  function swapEthToPipt(uint256 _slippage) public payable {
    (, uint256 swapAmount) = calcEthFee(msg.value);

    address[] memory tokens = pipt.getCurrentTokens();

    (, , uint256 poolAmountOut) = calcSwapEthToPiptInputs(swapAmount, tokens, _slippage);

    weth.deposit{ value: msg.value }();

    _swapWethToPiptByPoolOut(msg.value, poolAmountOut);
  }

  function swapEthToPiptByPoolOut(uint256 _poolAmountOut) external payable {
    weth.deposit{ value: msg.value }();

    _swapWethToPiptByPoolOut(msg.value, _poolAmountOut);
  }

  function swapPiptToEth(uint256 _poolAmountIn) external {
    uint256 ethOutAmount = _swapPiptToWeth(_poolAmountIn);

    weth.withdraw(ethOutAmount);
    msg.sender.transfer(ethOutAmount);
  }

  function convertOddToCvpAndSendToPayout(address[] memory oddTokens) external {
    require(msg.sender == tx.origin && !Address.isContract(msg.sender), "CONTRACT_NOT_ALLOWED");

    uint256 len = oddTokens.length;

    for (uint256 i = 0; i < len; i++) {
      uint256 tokenBalance = TokenInterface(oddTokens[i]).balanceOf(address(this));
      IUniswapV2Pair tokenPair = _uniswapPairFor(oddTokens[i]);

      (uint256 tokenReserve, uint256 ethReserve, ) = tokenPair.getReserves();
      uint256 wethOut = UniswapV2Library.getAmountOut(tokenBalance, tokenReserve, ethReserve);

      TokenInterface(oddTokens[i]).safeTransfer(address(tokenPair), tokenBalance);

      tokenPair.swap(uint256(0), wethOut, address(this), new bytes(0));
    }

    uint256 wethBalance = weth.balanceOf(address(this));

    IUniswapV2Pair cvpPair = _uniswapPairFor(address(cvp));

    (uint256 cvpReserve, uint256 ethReserve, ) = cvpPair.getReserves();
    uint256 cvpOut = UniswapV2Library.getAmountOut(wethBalance, ethReserve, cvpReserve);

    weth.safeTransfer(address(cvpPair), wethBalance);

    cvpPair.swap(cvpOut, uint256(0), address(this), new bytes(0));

    cvp.safeTransfer(feePayout, cvpOut);

    emit PayoutCVP(feePayout, wethBalance, cvpOut);
  }

  function setFees(
    uint256[] calldata _feeLevels,
    uint256[] calldata _feeAmounts,
    address _feePayout,
    address _feeManager
  ) external onlyFeeManagerOrOwner {
    feeLevels = _feeLevels;
    feeAmounts = _feeAmounts;
    feePayout = _feePayout;
    feeManager = _feeManager;

    emit SetFees(msg.sender, _feeLevels, _feeAmounts, _feePayout, _feeManager);
  }

  function setTokensSettings(
    address[] memory _tokens,
    address[] memory _pairs,
    bool[] memory _reapprove
  ) external onlyOwner {
    uint256 len = _tokens.length;
    require(len == _pairs.length && len == _reapprove.length, "LENGTHS_NOT_EQUAL");
    for (uint256 i = 0; i < _tokens.length; i++) {
      uniswapEthPairByTokenAddress[_tokens[i]] = _pairs[i];
      reApproveTokens[_tokens[i]] = _reapprove[i];
      emit SetTokenSetting(_tokens[i], _reapprove[i], _pairs[i]);
    }
  }

  function setUniswapFactoryAllowed(address[] memory _factories, bool[] memory _allowed) external onlyOwner {
    uint256 len = _factories.length;
    require(len == _allowed.length, "LENGTHS_NOT_EQUAL");
    for (uint256 i = 0; i < _factories.length; i++) {
      uniswapFactoryAllowed[_factories[i]] = _allowed[i];
      emit SetUniswapFactoryAllowed(_factories[i], _allowed[i]);
    }
  }

  function fetchUnswapPairsFromFactory(address _factory, address[] calldata _tokens) external {
    require(uniswapFactoryAllowed[_factory], "FACTORY_NOT_ALLOWED");

    uint256 len = _tokens.length;
    for (uint256 i = 0; i < _tokens.length; i++) {
      require(uniswapEthPairByTokenAddress[_tokens[i]] == address(0), "ALREADY_SET");
      uniswapEthPairByTokenAddress[_tokens[i]] = IUniswapV2Factory(_factory).getPair(_tokens[i], address(weth));
    }
  }

  function setDefaultSlippage(uint256 _defaultSlippage) external onlyOwner {
    defaultSlippage = _defaultSlippage;
    emit SetDefaultSlippage(_defaultSlippage);
  }

  function calcSwapEthToPiptInputs(
    uint256 _ethValue,
    address[] memory _tokens,
    uint256 _slippage
  )
    public
    view
    returns (
      uint256[] memory tokensInPipt,
      uint256[] memory ethInUniswap,
      uint256 poolOut
    )
  {
    _ethValue = _ethValue.sub(_ethValue.mul(_slippage).div(1 ether));

    // get shares and eth required for each share
    CalculationStruct[] memory calculations = new CalculationStruct[](_tokens.length);

    uint256 totalEthRequired = 0;
    {
      uint256 piptTotalSupply = pipt.totalSupply();
      // get pool out for 1 ether as 100% for calculate shares
      // poolOut by 1 ether first token join = piptTotalSupply.mul(1 ether).div(pipt.getBalance(_tokens[0]))
      // poolRatio = poolOut/totalSupply
      uint256 poolRatio =
        piptTotalSupply.mul(1 ether).div(pipt.getBalance(_tokens[0])).mul(1 ether).div(piptTotalSupply);

      for (uint256 i = 0; i < _tokens.length; i++) {
        // token share relatively 1 ether of first token
        calculations[i].tokenAmount = poolRatio.mul(pipt.getBalance(_tokens[i])).div(1 ether);

        (calculations[i].tokenReserve, calculations[i].ethReserve, ) = _uniswapPairFor(_tokens[i]).getReserves();
        calculations[i].ethAmount = UniswapV2Library.getAmountIn(
          calculations[i].tokenAmount,
          calculations[i].ethReserve,
          calculations[i].tokenReserve
        );
        totalEthRequired = totalEthRequired.add(calculations[i].ethAmount);
      }
    }

    // calculate eth and tokensIn based on shares and normalize if totalEthRequired more than 100%
    tokensInPipt = new uint256[](_tokens.length);
    ethInUniswap = new uint256[](_tokens.length);
    for (uint256 i = 0; i < _tokens.length; i++) {
      ethInUniswap[i] = _ethValue.mul(calculations[i].ethAmount.mul(1 ether).div(totalEthRequired)).div(1 ether);
      tokensInPipt[i] = calculations[i].tokenAmount.mul(_ethValue.mul(1 ether).div(totalEthRequired)).div(1 ether);
    }

    poolOut = pipt.totalSupply().mul(tokensInPipt[0]).div(pipt.getBalance(_tokens[0]));
  }

  function calcSwapPiptToEthInputs(uint256 _poolAmountIn, address[] memory _tokens)
    public
    view
    returns (
      uint256[] memory tokensOutPipt,
      uint256[] memory ethOutUniswap,
      uint256 totalEthOut,
      uint256 poolAmountFee
    )
  {
    tokensOutPipt = new uint256[](_tokens.length);
    ethOutUniswap = new uint256[](_tokens.length);

    (, , uint256 communityExitFee, ) = pipt.getCommunityFee();

    uint256 poolAmountInAfterFee;
    (poolAmountInAfterFee, poolAmountFee) = pipt.calcAmountWithCommunityFee(
      _poolAmountIn,
      communityExitFee,
      address(this)
    );

    uint256 poolRatio = poolAmountInAfterFee.mul(1 ether).div(pipt.totalSupply());

    totalEthOut = 0;
    for (uint256 i = 0; i < _tokens.length; i++) {
      tokensOutPipt[i] = poolRatio.mul(pipt.getBalance(_tokens[i])).div(1 ether);

      (uint256 tokenReserve, uint256 ethReserve, ) = _uniswapPairFor(_tokens[i]).getReserves();
      ethOutUniswap[i] = UniswapV2Library.getAmountOut(tokensOutPipt[i], tokenReserve, ethReserve);
      totalEthOut = totalEthOut.add(ethOutUniswap[i]);
    }
  }

  function calcEthFee(uint256 ethAmount) public view returns (uint256 ethFee, uint256 ethAfterFee) {
    ethFee = 0;
    uint256 len = feeLevels.length;
    for (uint256 i = 0; i < len; i++) {
      if (ethAmount >= feeLevels[i]) {
        ethFee = ethAmount.mul(feeAmounts[i]).div(1 ether);
        break;
      }
    }
    ethAfterFee = ethAmount.sub(ethFee);
  }

  function getFeeLevels() external view returns (uint256[] memory) {
    return feeLevels;
  }

  function getFeeAmounts() external view returns (uint256[] memory) {
    return feeAmounts;
  }

  function _uniswapPairFor(address token) internal view returns (IUniswapV2Pair) {
    return IUniswapV2Pair(uniswapEthPairByTokenAddress[token]);
  }

  function _swapWethToPiptByPoolOut(uint256 _wethAmount, uint256 _poolAmountOut) internal {
    require(_wethAmount > 0, "ETH_REQUIRED");

    {
      address poolRestrictions = pipt.getRestrictions();
      if (address(poolRestrictions) != address(0)) {
        uint256 maxTotalSupply = IPoolRestrictions(poolRestrictions).getMaxTotalSupply(address(pipt));
        require(pipt.totalSupply().add(_poolAmountOut) <= maxTotalSupply, "PIPT_MAX_SUPPLY");
      }
    }

    (uint256 feeAmount, uint256 swapAmount) = calcEthFee(_wethAmount);

    uint256 ratio = _poolAmountOut.mul(1 ether).div(pipt.totalSupply()).add(10);

    address[] memory tokens = pipt.getCurrentTokens();
    uint256 len = tokens.length;

    CalculationStruct[] memory calculations = new CalculationStruct[](tokens.length);
    uint256[] memory tokensInPipt = new uint256[](tokens.length);

    uint256 totalEthSwap = 0;
    for (uint256 i = 0; i < len; i++) {
      IUniswapV2Pair tokenPair = _uniswapPairFor(tokens[i]);

      (calculations[i].tokenReserve, calculations[i].ethReserve, ) = tokenPair.getReserves();
      tokensInPipt[i] = ratio.mul(pipt.getBalance(tokens[i])).div(1 ether);
      calculations[i].ethAmount = UniswapV2Library.getAmountIn(
        tokensInPipt[i],
        calculations[i].ethReserve,
        calculations[i].tokenReserve
      );

      weth.safeTransfer(address(tokenPair), calculations[i].ethAmount);

      tokenPair.swap(tokensInPipt[i], uint256(0), address(this), new bytes(0));
      totalEthSwap = totalEthSwap.add(calculations[i].ethAmount);

      if (reApproveTokens[tokens[i]]) {
        TokenInterface(tokens[i]).approve(address(pipt), 0);
      }

      TokenInterface(tokens[i]).approve(address(pipt), tokensInPipt[i]);
    }

    (, uint256 communityJoinFee, , ) = pipt.getCommunityFee();
    (uint256 poolAmountOutAfterFee, uint256 poolAmountOutFee) =
      pipt.calcAmountWithCommunityFee(_poolAmountOut, communityJoinFee, address(this));

    emit EthToPiptSwap(msg.sender, swapAmount, feeAmount, _poolAmountOut, poolAmountOutFee);

    pipt.joinPool(_poolAmountOut, tokensInPipt);
    pipt.safeTransfer(msg.sender, poolAmountOutAfterFee);

    uint256 ethDiff = swapAmount.sub(totalEthSwap);
    if (ethDiff > 0) {
      weth.withdraw(ethDiff);
      msg.sender.transfer(ethDiff);
      emit OddEth(msg.sender, ethDiff);
    }
  }

  function _swapPiptToWeth(uint256 _poolAmountIn) internal returns (uint256) {
    address[] memory tokens = pipt.getCurrentTokens();
    uint256 len = tokens.length;

    (uint256[] memory tokensOutPipt, uint256[] memory ethOutUniswap, uint256 totalEthOut, uint256 poolAmountFee) =
      calcSwapPiptToEthInputs(_poolAmountIn, tokens);

    pipt.safeTransferFrom(msg.sender, address(this), _poolAmountIn);

    pipt.approve(address(pipt), _poolAmountIn);

    pipt.exitPool(_poolAmountIn, tokensOutPipt);

    for (uint256 i = 0; i < len; i++) {
      IUniswapV2Pair tokenPair = _uniswapPairFor(tokens[i]);
      TokenInterface(tokens[i]).safeTransfer(address(tokenPair), tokensOutPipt[i]);
      tokenPair.swap(uint256(0), ethOutUniswap[i], address(this), new bytes(0));
    }

    (uint256 ethFeeAmount, uint256 ethOutAmount) = calcEthFee(totalEthOut);

    emit PiptToEthSwap(msg.sender, _poolAmountIn, poolAmountFee, ethOutAmount, ethFeeAmount);

    return ethOutAmount;
  }
}

// File: contracts/Erc20PiptSwap.sol

pragma solidity 0.6.12;


contract Erc20PiptSwap is EthPiptSwap {
  event Erc20ToPiptSwap(
    address indexed user,
    address indexed swapToken,
    uint256 erc20InAmount,
    uint256 ethInAmount,
    uint256 poolOutAmount
  );
  event PiptToErc20Swap(
    address indexed user,
    address indexed swapToken,
    uint256 poolInAmount,
    uint256 ethOutAmount,
    uint256 erc20OutAmount
  );

  constructor(
    address _weth,
    address _cvp,
    address _pipt,
    address _feeManager
  ) public EthPiptSwap(_weth, _cvp, _pipt, _feeManager) {}

  function swapErc20ToPipt(
    address _swapToken,
    uint256 _swapAmount,
    uint256 _slippage
  ) external {
    IERC20(_swapToken).safeTransferFrom(msg.sender, address(this), _swapAmount);

    IUniswapV2Pair tokenPair = _uniswapPairFor(_swapToken);
    (uint256 tokenReserve, uint256 ethReserve, ) = tokenPair.getReserves();
    uint256 ethAmount = UniswapV2Library.getAmountOut(_swapAmount, tokenReserve, ethReserve);

    IERC20(_swapToken).safeTransfer(address(tokenPair), _swapAmount);
    tokenPair.swap(uint256(0), ethAmount, address(this), new bytes(0));

    (, uint256 ethSwapAmount) = calcEthFee(ethAmount);
    address[] memory tokens = pipt.getCurrentTokens();
    (, , uint256 poolAmountOut) = calcSwapEthToPiptInputs(ethSwapAmount, tokens, _slippage);

    _swapWethToPiptByPoolOut(ethAmount, poolAmountOut);

    emit Erc20ToPiptSwap(msg.sender, _swapToken, _swapAmount, ethAmount, poolAmountOut);
  }

  function swapPiptToErc20(address _swapToken, uint256 _poolAmountIn) external {
    uint256 ethOut = _swapPiptToWeth(_poolAmountIn);

    IUniswapV2Pair tokenPair = _uniswapPairFor(_swapToken);

    (uint256 tokenReserve, uint256 ethReserve, ) = tokenPair.getReserves();
    uint256 erc20Out = UniswapV2Library.getAmountOut(ethOut, ethReserve, tokenReserve);

    weth.safeTransfer(address(tokenPair), ethOut);

    tokenPair.swap(erc20Out, uint256(0), address(this), new bytes(0));

    IERC20(_swapToken).safeTransfer(msg.sender, erc20Out);

    emit PiptToErc20Swap(msg.sender, _swapToken, _poolAmountIn, ethOut, erc20Out);
  }

  function calcSwapErc20ToPiptInputs(
    address _swapToken,
    uint256 _swapAmount,
    address[] memory _tokens,
    uint256 _slippage,
    bool _withFee
  )
    external
    view
    returns (
      uint256[] memory tokensInPipt,
      uint256[] memory ethInUniswap,
      uint256 poolOut
    )
  {
    (uint256 tokenReserve, uint256 ethReserve, ) = _uniswapPairFor(_swapToken).getReserves();
    uint256 ethAmount = UniswapV2Library.getAmountOut(_swapAmount, tokenReserve, ethReserve);
    if (_withFee) {
      (, ethAmount) = calcEthFee(ethAmount);
    }
    return calcSwapEthToPiptInputs(ethAmount, _tokens, _slippage);
  }

  function calcSwapPiptToErc20Inputs(
    address _swapToken,
    uint256 _poolAmountIn,
    address[] memory _tokens,
    bool _withFee
  )
    external
    view
    returns (
      uint256[] memory tokensOutPipt,
      uint256[] memory ethOutUniswap,
      uint256 totalErc20Out,
      uint256 poolAmountFee
    )
  {
    uint256 totalEthOut;

    (tokensOutPipt, ethOutUniswap, totalEthOut, poolAmountFee) = calcSwapPiptToEthInputs(_poolAmountIn, _tokens);
    if (_withFee) {
      (, totalEthOut) = calcEthFee(totalEthOut);
    }
    (uint256 tokenReserve, uint256 ethReserve, ) = _uniswapPairFor(_swapToken).getReserves();
    totalErc20Out = UniswapV2Library.getAmountOut(totalEthOut, ethReserve, tokenReserve);
  }

  function calcErc20Fee(address _swapToken, uint256 _swapAmount)
    external
    view
    returns (
      uint256 erc20Fee,
      uint256 erc20AfterFee,
      uint256 ethFee,
      uint256 ethAfterFee
    )
  {
    (uint256 tokenReserve, uint256 ethReserve, ) = _uniswapPairFor(_swapToken).getReserves();
    uint256 ethAmount = UniswapV2Library.getAmountOut(_swapAmount, tokenReserve, ethReserve);

    (ethFee, ethAfterFee) = calcEthFee(ethAmount);

    if (ethFee != 0) {
      erc20Fee = UniswapV2Library.getAmountOut(ethFee, ethReserve, tokenReserve);
    }
    erc20AfterFee = UniswapV2Library.getAmountOut(ethAfterFee, ethReserve, tokenReserve);
  }
}