// File: contracts/balancer/BPool.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

import "./BToken.sol";
import "./BMath.sol";

// Core contract; can't be changed. So disable solhint (reminder for v2)

/* solhint-disable func-order */
/* solhint-disable event-name-camelcase */

contract BPool is BBronze, BToken, BMath {
    struct Record {
        bool bound; // is token bound to pool
        uint256 index; // private
        uint256 denorm; // denormalized weight
        uint256 balance;
    }

    event LOG_SWAP(
        address indexed caller,
        address indexed tokenIn,
        address indexed tokenOut,
        uint256 tokenAmountIn,
        uint256 tokenAmountOut
    );

    event LOG_JOIN(address indexed caller, address indexed tokenIn, uint256 tokenAmountIn);

    event LOG_EXIT(address indexed caller, address indexed tokenOut, uint256 tokenAmountOut);

    event LOG_CALL(bytes4 indexed sig, address indexed caller, bytes data) anonymous;

    modifier _logs_() {
        emit LOG_CALL(msg.sig, msg.sender, msg.data);
        _;
    }

    modifier _lock_() {
        require(!_mutex, "ERR_REENTRY");
        _mutex = true;
        _;
        _mutex = false;
    }

    modifier _viewlock_() {
        require(!_mutex, "ERR_REENTRY");
        _;
    }

    bool private _mutex;

    address private _factory; // BFactory address to push token exitFee to
    address private _controller; // has CONTROL role
    bool private _publicSwap; // true if PUBLIC can call SWAP functions

    // `setSwapFee` and `finalize` require CONTROL
    // `finalize` sets `PUBLIC can SWAP`, `PUBLIC can JOIN`
    uint256 private _swapFee;
    bool private _finalized;

    address[] private _tokens;
    mapping(address => Record) private _records;
    uint256 private _totalWeight;

    bool public initialized;

    constructor() public {
        initialized = true;
    }

    function init() public {
        require(initialized == false, "Pool already initialized");
        _controller = msg.sender;
        _factory = msg.sender;
        _swapFee = MIN_FEE;
        _publicSwap = false;
        _finalized = false;
    }

    function isPublicSwap() external view returns (bool) {
        return _publicSwap;
    }

    function isFinalized() external view returns (bool) {
        return _finalized;
    }

    function isBound(address t) external view returns (bool) {
        return _records[t].bound;
    }

    function getNumTokens() external view returns (uint256) {
        return _tokens.length;
    }

    function getCurrentTokens() external view _viewlock_ returns (address[] memory tokens) {
        return _tokens;
    }

    function getFinalTokens() external view _viewlock_ returns (address[] memory tokens) {
        require(_finalized, "ERR_NOT_FINALIZED");
        return _tokens;
    }

    function getDenormalizedWeight(address token) external view _viewlock_ returns (uint256) {
        require(_records[token].bound, "ERR_NOT_BOUND");
        return _records[token].denorm;
    }

    function getTotalDenormalizedWeight() external view _viewlock_ returns (uint256) {
        return _totalWeight;
    }

    function getNormalizedWeight(address token) external view _viewlock_ returns (uint256) {
        require(_records[token].bound, "ERR_NOT_BOUND");
        uint256 denorm = _records[token].denorm;
        return bdiv(denorm, _totalWeight);
    }

    function getBalance(address token) external view _viewlock_ returns (uint256) {
        require(_records[token].bound, "ERR_NOT_BOUND");
        return _records[token].balance;
    }

    function getSwapFee() external view _viewlock_ returns (uint256) {
        return _swapFee;
    }

    function getController() external view _viewlock_ returns (address) {
        return _controller;
    }

    function setSwapFee(uint256 swapFee) external _logs_ _lock_ {
        require(!_finalized, "ERR_IS_FINALIZED");
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(swapFee >= MIN_FEE, "ERR_MIN_FEE");
        require(swapFee <= MAX_FEE, "ERR_MAX_FEE");
        _swapFee = swapFee;
    }

    function setController(address manager) external _logs_ _lock_ {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        _controller = manager;
    }

    function setPublicSwap(bool public_) external _logs_ _lock_ {
        require(!_finalized, "ERR_IS_FINALIZED");
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        _publicSwap = public_;
    }

    function finalize() external _logs_ _lock_ {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(!_finalized, "ERR_IS_FINALIZED");
        require(_tokens.length >= MIN_BOUND_TOKENS, "ERR_MIN_TOKENS");

        _finalized = true;
        _publicSwap = true;

        _mintPoolShare(INIT_POOL_SUPPLY);
        _pushPoolShare(msg.sender, INIT_POOL_SUPPLY);
    }

    function bind(
        address token,
        uint256 balance,
        uint256 denorm
    )
        external
        _logs_ // _lock_  Bind does not lock because it jumps to `rebind`, which does
    {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(!_records[token].bound, "ERR_IS_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

        require(_tokens.length < MAX_BOUND_TOKENS, "ERR_MAX_TOKENS");

        _records[token] = Record({
            bound: true,
            index: _tokens.length,
            denorm: 0, // balance and denorm will be validated
            balance: 0 // and set by `rebind`
        });
        _tokens.push(token);
        rebind(token, balance, denorm);
    }

    function rebind(
        address token,
        uint256 balance,
        uint256 denorm
    ) public _logs_ _lock_ {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(_records[token].bound, "ERR_NOT_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

        require(denorm >= MIN_WEIGHT, "ERR_MIN_WEIGHT");
        require(denorm <= MAX_WEIGHT, "ERR_MAX_WEIGHT");
        require(balance >= MIN_BALANCE, "ERR_MIN_BALANCE");

        // Adjust the denorm and totalWeight
        uint256 oldWeight = _records[token].denorm;
        if (denorm > oldWeight) {
            _totalWeight = badd(_totalWeight, bsub(denorm, oldWeight));
            require(_totalWeight <= MAX_TOTAL_WEIGHT, "ERR_MAX_TOTAL_WEIGHT");
        } else if (denorm < oldWeight) {
            _totalWeight = bsub(_totalWeight, bsub(oldWeight, denorm));
        }
        _records[token].denorm = denorm;

        // Adjust the balance record and actual token balance
        uint256 oldBalance = _records[token].balance;
        _records[token].balance = balance;
        if (balance > oldBalance) {
            _pullUnderlying(token, msg.sender, bsub(balance, oldBalance));
        } else if (balance < oldBalance) {
            // In this case liquidity is being withdrawn, so charge EXIT_FEE
            uint256 tokenBalanceWithdrawn = bsub(oldBalance, balance);
            uint256 tokenExitFee = bmul(tokenBalanceWithdrawn, EXIT_FEE);
            _pushUnderlying(token, msg.sender, bsub(tokenBalanceWithdrawn, tokenExitFee));
            _pushUnderlying(token, _factory, tokenExitFee);
        }
    }

    function unbind(address token) external _logs_ _lock_ {
        require(msg.sender == _controller, "ERR_NOT_CONTROLLER");
        require(_records[token].bound, "ERR_NOT_BOUND");
        require(!_finalized, "ERR_IS_FINALIZED");

        uint256 tokenBalance = _records[token].balance;
        uint256 tokenExitFee = bmul(tokenBalance, EXIT_FEE);

        _totalWeight = bsub(_totalWeight, _records[token].denorm);

        // Swap the token-to-unbind with the last token,
        // then delete the last token
        uint256 index = _records[token].index;
        uint256 last = _tokens.length - 1;
        _tokens[index] = _tokens[last];
        _records[_tokens[index]].index = index;
        _tokens.pop();
        _records[token] = Record({bound: false, index: 0, denorm: 0, balance: 0});

        _pushUnderlying(token, msg.sender, bsub(tokenBalance, tokenExitFee));
        _pushUnderlying(token, _factory, tokenExitFee);
    }

    // Absorb any tokens that have been sent to this contract into the pool
    function gulp(address token) external _logs_ _lock_ {
        require(_records[token].bound, "ERR_NOT_BOUND");
        _records[token].balance = IERC20(token).balanceOf(address(this));
    }

    function getSpotPrice(address tokenIn, address tokenOut) external view _viewlock_ returns (uint256 spotPrice) {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        Record storage inRecord = _records[tokenIn];
        Record storage outRecord = _records[tokenOut];
        return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, _swapFee);
    }

    function getSpotPriceSansFee(address tokenIn, address tokenOut)
        external
        view
        _viewlock_
        returns (uint256 spotPrice)
    {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        Record storage inRecord = _records[tokenIn];
        Record storage outRecord = _records[tokenOut];
        return calcSpotPrice(inRecord.balance, inRecord.denorm, outRecord.balance, outRecord.denorm, 0);
    }

    function joinPool(uint256 poolAmountOut, uint256[] calldata maxAmountsIn) external _logs_ _lock_ {
        require(_finalized, "ERR_NOT_FINALIZED");

        uint256 poolTotal = totalSupply();
        uint256 ratio = bdiv(poolAmountOut, poolTotal);
        require(ratio != 0, "ERR_MATH_APPROX");

        for (uint256 i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint256 bal = _records[t].balance;
            uint256 tokenAmountIn = bmul(ratio, bal);
            require(tokenAmountIn != 0, "ERR_MATH_APPROX");
            require(tokenAmountIn <= maxAmountsIn[i], "ERR_LIMIT_IN");
            _records[t].balance = badd(_records[t].balance, tokenAmountIn);
            emit LOG_JOIN(msg.sender, t, tokenAmountIn);
            _pullUnderlying(t, msg.sender, tokenAmountIn);
        }
        _mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
    }

    function exitPool(uint256 poolAmountIn, uint256[] calldata minAmountsOut) external _logs_ _lock_ {
        require(_finalized, "ERR_NOT_FINALIZED");

        uint256 poolTotal = totalSupply();
        uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);
        uint256 pAiAfterExitFee = bsub(poolAmountIn, exitFee);
        uint256 ratio = bdiv(pAiAfterExitFee, poolTotal);
        require(ratio != 0, "ERR_MATH_APPROX");

        _pullPoolShare(msg.sender, poolAmountIn);
        _pushPoolShare(_factory, exitFee);
        _burnPoolShare(pAiAfterExitFee);

        for (uint256 i = 0; i < _tokens.length; i++) {
            address t = _tokens[i];
            uint256 bal = _records[t].balance;
            uint256 tokenAmountOut = bmul(ratio, bal);
            require(tokenAmountOut != 0, "ERR_MATH_APPROX");
            require(tokenAmountOut >= minAmountsOut[i], "ERR_LIMIT_OUT");
            _records[t].balance = bsub(_records[t].balance, tokenAmountOut);
            emit LOG_EXIT(msg.sender, t, tokenAmountOut);
            _pushUnderlying(t, msg.sender, tokenAmountOut);
        }
    }

    function swapExactAmountIn(
        address tokenIn,
        uint256 tokenAmountIn,
        address tokenOut,
        uint256 minAmountOut,
        uint256 maxPrice
    ) external _logs_ _lock_ returns (uint256 tokenAmountOut, uint256 spotPriceAfter) {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

        Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

        require(tokenAmountIn <= bmul(inRecord.balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

        uint256 spotPriceBefore = calcSpotPrice(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            _swapFee
        );
        require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");

        tokenAmountOut = calcOutGivenIn(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            tokenAmountIn,
            _swapFee
        );
        require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

        inRecord.balance = badd(inRecord.balance, tokenAmountIn);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

        spotPriceAfter = calcSpotPrice(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            _swapFee
        );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

        emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

        return (tokenAmountOut, spotPriceAfter);
    }

    function swapExactAmountOut(
        address tokenIn,
        uint256 maxAmountIn,
        address tokenOut,
        uint256 tokenAmountOut,
        uint256 maxPrice
    ) external _logs_ _lock_ returns (uint256 tokenAmountIn, uint256 spotPriceAfter) {
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(_publicSwap, "ERR_SWAP_NOT_PUBLIC");

        Record storage inRecord = _records[address(tokenIn)];
        Record storage outRecord = _records[address(tokenOut)];

        require(tokenAmountOut <= bmul(outRecord.balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

        uint256 spotPriceBefore = calcSpotPrice(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            _swapFee
        );
        require(spotPriceBefore <= maxPrice, "ERR_BAD_LIMIT_PRICE");

        tokenAmountIn = calcInGivenOut(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            tokenAmountOut,
            _swapFee
        );
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

        inRecord.balance = badd(inRecord.balance, tokenAmountIn);
        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

        spotPriceAfter = calcSpotPrice(
            inRecord.balance,
            inRecord.denorm,
            outRecord.balance,
            outRecord.denorm,
            _swapFee
        );
        require(spotPriceAfter >= spotPriceBefore, "ERR_MATH_APPROX");
        require(spotPriceAfter <= maxPrice, "ERR_LIMIT_PRICE");
        require(spotPriceBefore <= bdiv(tokenAmountIn, tokenAmountOut), "ERR_MATH_APPROX");

        emit LOG_SWAP(msg.sender, tokenIn, tokenOut, tokenAmountIn, tokenAmountOut);

        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

        return (tokenAmountIn, spotPriceAfter);
    }

    function joinswapExternAmountIn(
        address tokenIn,
        uint256 tokenAmountIn,
        uint256 minPoolAmountOut
    ) external _logs_ _lock_ returns (uint256 poolAmountOut) {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");
        require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

        Record storage inRecord = _records[tokenIn];

        poolAmountOut = calcPoolOutGivenSingleIn(
            inRecord.balance,
            inRecord.denorm,
            _totalSupply,
            _totalWeight,
            tokenAmountIn,
            _swapFee
        );

        require(poolAmountOut >= minPoolAmountOut, "ERR_LIMIT_OUT");

        inRecord.balance = badd(inRecord.balance, tokenAmountIn);

        emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

        _mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

        return poolAmountOut;
    }

    function joinswapPoolAmountOut(
        address tokenIn,
        uint256 poolAmountOut,
        uint256 maxAmountIn
    ) external _logs_ _lock_ returns (uint256 tokenAmountIn) {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenIn].bound, "ERR_NOT_BOUND");

        Record storage inRecord = _records[tokenIn];

        tokenAmountIn = calcSingleInGivenPoolOut(
            inRecord.balance,
            inRecord.denorm,
            _totalSupply,
            _totalWeight,
            poolAmountOut,
            _swapFee
        );

        require(tokenAmountIn != 0, "ERR_MATH_APPROX");
        require(tokenAmountIn <= maxAmountIn, "ERR_LIMIT_IN");

        require(tokenAmountIn <= bmul(_records[tokenIn].balance, MAX_IN_RATIO), "ERR_MAX_IN_RATIO");

        inRecord.balance = badd(inRecord.balance, tokenAmountIn);

        emit LOG_JOIN(msg.sender, tokenIn, tokenAmountIn);

        _mintPoolShare(poolAmountOut);
        _pushPoolShare(msg.sender, poolAmountOut);
        _pullUnderlying(tokenIn, msg.sender, tokenAmountIn);

        return tokenAmountIn;
    }

    function exitswapPoolAmountIn(
        address tokenOut,
        uint256 poolAmountIn,
        uint256 minAmountOut
    ) external _logs_ _lock_ returns (uint256 tokenAmountOut) {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");

        Record storage outRecord = _records[tokenOut];

        tokenAmountOut = calcSingleOutGivenPoolIn(
            outRecord.balance,
            outRecord.denorm,
            _totalSupply,
            _totalWeight,
            poolAmountIn,
            _swapFee
        );

        require(tokenAmountOut >= minAmountOut, "ERR_LIMIT_OUT");

        require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

        uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);

        emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

        _pullPoolShare(msg.sender, poolAmountIn);
        _burnPoolShare(bsub(poolAmountIn, exitFee));
        _pushPoolShare(_factory, exitFee);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

        return tokenAmountOut;
    }

    function exitswapExternAmountOut(
        address tokenOut,
        uint256 tokenAmountOut,
        uint256 maxPoolAmountIn
    ) external _logs_ _lock_ returns (uint256 poolAmountIn) {
        require(_finalized, "ERR_NOT_FINALIZED");
        require(_records[tokenOut].bound, "ERR_NOT_BOUND");
        require(tokenAmountOut <= bmul(_records[tokenOut].balance, MAX_OUT_RATIO), "ERR_MAX_OUT_RATIO");

        Record storage outRecord = _records[tokenOut];

        poolAmountIn = calcPoolInGivenSingleOut(
            outRecord.balance,
            outRecord.denorm,
            _totalSupply,
            _totalWeight,
            tokenAmountOut,
            _swapFee
        );

        require(poolAmountIn != 0, "ERR_MATH_APPROX");
        require(poolAmountIn <= maxPoolAmountIn, "ERR_LIMIT_IN");

        outRecord.balance = bsub(outRecord.balance, tokenAmountOut);

        uint256 exitFee = bmul(poolAmountIn, EXIT_FEE);

        emit LOG_EXIT(msg.sender, tokenOut, tokenAmountOut);

        _pullPoolShare(msg.sender, poolAmountIn);
        _burnPoolShare(bsub(poolAmountIn, exitFee));
        _pushPoolShare(_factory, exitFee);
        _pushUnderlying(tokenOut, msg.sender, tokenAmountOut);

        return poolAmountIn;
    }

    // ==
    // 'Underlying' token-manipulation functions make external calls but are NOT locked
    // You must `_lock_` or otherwise ensure reentry-safety

    function _pullUnderlying(
        address erc20,
        address from,
        uint256 amount
    ) internal {
        bool xfer = IERC20(erc20).transferFrom(from, address(this), amount);
        require(xfer, "ERR_ERC20_FALSE");
    }

    function _pushUnderlying(
        address erc20,
        address to,
        uint256 amount
    ) internal {
        bool xfer = IERC20(erc20).transfer(to, amount);
        require(xfer, "ERR_ERC20_FALSE");
    }

    function _pullPoolShare(address from, uint256 amount) internal {
        _pull(from, amount);
    }

    function _pushPoolShare(address to, uint256 amount) internal {
        _push(to, amount);
    }

    function _mintPoolShare(uint256 amount) internal {
        _mint(amount);
    }

    function _burnPoolShare(uint256 amount) internal {
        _burn(amount);
    }
}

// File: contracts/balancer/BToken.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

import "./BNum.sol";
import "./PCToken.sol";

// Highly opinionated token implementation

/*
interface IERC20 {
    event Approval(address indexed src, address indexed dst, uint amt);
    event Transfer(address indexed src, address indexed dst, uint amt);

    function totalSupply() external view returns (uint);
    function balanceOf(address whom) external view returns (uint);
    function allowance(address src, address dst) external view returns (uint);

    function approve(address dst, uint amt) external returns (bool);
    function transfer(address dst, uint amt) external returns (bool);
    function transferFrom(
        address src, address dst, uint amt
    ) external returns (bool);
}
*/

// Core contract; can't be changed. So disable solhint (reminder for v2)

/* solhint-disable func-order */

contract BTokenBase is BNum {
    mapping(address => uint256) internal _balance;
    mapping(address => mapping(address => uint256)) internal _allowance;
    uint256 internal _totalSupply;

    event Approval(address indexed src, address indexed dst, uint256 amt);
    event Transfer(address indexed src, address indexed dst, uint256 amt);

    function _mint(uint256 amt) internal {
        _balance[address(this)] = badd(_balance[address(this)], amt);
        _totalSupply = badd(_totalSupply, amt);
        emit Transfer(address(0), address(this), amt);
    }

    function _burn(uint256 amt) internal {
        require(_balance[address(this)] >= amt, "ERR_INSUFFICIENT_BAL");
        _balance[address(this)] = bsub(_balance[address(this)], amt);
        _totalSupply = bsub(_totalSupply, amt);
        emit Transfer(address(this), address(0), amt);
    }

    function _move(
        address src,
        address dst,
        uint256 amt
    ) internal {
        require(_balance[src] >= amt, "ERR_INSUFFICIENT_BAL");
        _balance[src] = bsub(_balance[src], amt);
        _balance[dst] = badd(_balance[dst], amt);
        emit Transfer(src, dst, amt);
    }

    function _push(address to, uint256 amt) internal {
        _move(address(this), to, amt);
    }

    function _pull(address from, uint256 amt) internal {
        _move(from, address(this), amt);
    }
}

contract BToken is BTokenBase, IERC20 {
    string private _name = "Balancer Pool Token";
    string private _symbol = "BPT";
    uint8 private _decimals = 18;

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function allowance(address src, address dst) external view override returns (uint256) {
        return _allowance[src][dst];
    }

    function balanceOf(address whom) external view override returns (uint256) {
        return _balance[whom];
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function approve(address dst, uint256 amt) external override returns (bool) {
        _allowance[msg.sender][dst] = amt;
        emit Approval(msg.sender, dst, amt);
        return true;
    }

    function increaseApproval(address dst, uint256 amt) external returns (bool) {
        _allowance[msg.sender][dst] = badd(_allowance[msg.sender][dst], amt);
        emit Approval(msg.sender, dst, _allowance[msg.sender][dst]);
        return true;
    }

    function decreaseApproval(address dst, uint256 amt) external returns (bool) {
        uint256 oldValue = _allowance[msg.sender][dst];
        if (amt > oldValue) {
            _allowance[msg.sender][dst] = 0;
        } else {
            _allowance[msg.sender][dst] = bsub(oldValue, amt);
        }
        emit Approval(msg.sender, dst, _allowance[msg.sender][dst]);
        return true;
    }

    function transfer(address dst, uint256 amt) external override returns (bool) {
        _move(msg.sender, dst, amt);
        return true;
    }

    function transferFrom(
        address src,
        address dst,
        uint256 amt
    ) external override returns (bool) {
        require(msg.sender == src || amt <= _allowance[src][msg.sender], "ERR_BTOKEN_BAD_CALLER");
        _move(src, dst, amt);
        if (msg.sender != src && _allowance[src][msg.sender] != uint256(-1)) {
            _allowance[src][msg.sender] = bsub(_allowance[src][msg.sender], amt);
            emit Approval(msg.sender, dst, _allowance[src][msg.sender]);
        }
        return true;
    }
}

// File: contracts/balancer/BMath.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

import "./BNum.sol";

contract BMath is BBronze, BConst, BNum {
    /**********************************************************************************************
    // calcSpotPrice                                                                             //
    // sP = spotPrice                                                                            //
    // bI = tokenBalanceIn                ( bI / wI )         1                                  //
    // bO = tokenBalanceOut         sP =  -----------  *  ----------                             //
    // wI = tokenWeightIn                 ( bO / wO )     ( 1 - sF )                             //
    // wO = tokenWeightOut                                                                       //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
    function calcSpotPrice(
        uint256 tokenBalanceIn,
        uint256 tokenWeightIn,
        uint256 tokenBalanceOut,
        uint256 tokenWeightOut,
        uint256 swapFee
    ) public pure returns (uint256 spotPrice) {
        uint256 numer = bdiv(tokenBalanceIn, tokenWeightIn);
        uint256 denom = bdiv(tokenBalanceOut, tokenWeightOut);
        uint256 ratio = bdiv(numer, denom);
        uint256 scale = bdiv(BONE, bsub(BONE, swapFee));
        return (spotPrice = bmul(ratio, scale));
    }

    /**********************************************************************************************
    // calcOutGivenIn                                                                            //
    // aO = tokenAmountOut                                                                       //
    // bO = tokenBalanceOut                                                                      //
    // bI = tokenBalanceIn              /      /            bI             \    (wI / wO) \      //
    // aI = tokenAmountIn    aO = bO * |  1 - | --------------------------  | ^            |     //
    // wI = tokenWeightIn               \      \ ( bI + ( aI * ( 1 - sF )) /              /      //
    // wO = tokenWeightOut                                                                       //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
    function calcOutGivenIn(
        uint256 tokenBalanceIn,
        uint256 tokenWeightIn,
        uint256 tokenBalanceOut,
        uint256 tokenWeightOut,
        uint256 tokenAmountIn,
        uint256 swapFee
    ) public pure returns (uint256 tokenAmountOut) {
        uint256 weightRatio = bdiv(tokenWeightIn, tokenWeightOut);
        uint256 adjustedIn = bsub(BONE, swapFee);
        adjustedIn = bmul(tokenAmountIn, adjustedIn);
        uint256 y = bdiv(tokenBalanceIn, badd(tokenBalanceIn, adjustedIn));
        uint256 foo = bpow(y, weightRatio);
        uint256 bar = bsub(BONE, foo);
        tokenAmountOut = bmul(tokenBalanceOut, bar);
        return tokenAmountOut;
    }

    /**********************************************************************************************
    // calcInGivenOut                                                                            //
    // aI = tokenAmountIn                                                                        //
    // bO = tokenBalanceOut               /  /     bO      \    (wO / wI)      \                 //
    // bI = tokenBalanceIn          bI * |  | ------------  | ^            - 1  |                //
    // aO = tokenAmountOut    aI =        \  \ ( bO - aO ) /                   /                 //
    // wI = tokenWeightIn           --------------------------------------------                 //
    // wO = tokenWeightOut                          ( 1 - sF )                                   //
    // sF = swapFee                                                                              //
    **********************************************************************************************/
    function calcInGivenOut(
        uint256 tokenBalanceIn,
        uint256 tokenWeightIn,
        uint256 tokenBalanceOut,
        uint256 tokenWeightOut,
        uint256 tokenAmountOut,
        uint256 swapFee
    ) public pure returns (uint256 tokenAmountIn) {
        uint256 weightRatio = bdiv(tokenWeightOut, tokenWeightIn);
        uint256 diff = bsub(tokenBalanceOut, tokenAmountOut);
        uint256 y = bdiv(tokenBalanceOut, diff);
        uint256 foo = bpow(y, weightRatio);
        foo = bsub(foo, BONE);
        tokenAmountIn = bsub(BONE, swapFee);
        tokenAmountIn = bdiv(bmul(tokenBalanceIn, foo), tokenAmountIn);
        return tokenAmountIn;
    }

    /**********************************************************************************************
    // calcPoolOutGivenSingleIn                                                                  //
    // pAo = poolAmountOut         /                                              \              //
    // tAi = tokenAmountIn        ///      /     //    wI \      \\       \     wI \             //
    // wI = tokenWeightIn        //| tAi *| 1 - || 1 - --  | * sF || + tBi \    --  \            //
    // tW = totalWeight     pAo=||  \      \     \\    tW /      //         | ^ tW   | * pS - pS //
    // tBi = tokenBalanceIn      \\  ------------------------------------- /        /            //
    // pS = poolSupply            \\                    tBi               /        /             //
    // sF = swapFee                \                                              /              //
    **********************************************************************************************/
    function calcPoolOutGivenSingleIn(
        uint256 tokenBalanceIn,
        uint256 tokenWeightIn,
        uint256 poolSupply,
        uint256 totalWeight,
        uint256 tokenAmountIn,
        uint256 swapFee
    ) public pure returns (uint256 poolAmountOut) {
        // Charge the trading fee for the proportion of tokenAi
        // which is implicitly traded to the other pool tokens.
        // That proportion is (1- weightTokenIn)
        // tokenAiAfterFee = tAi * (1 - (1-weightTi) * poolFee);
        uint256 normalizedWeight = bdiv(tokenWeightIn, totalWeight);
        uint256 zaz = bmul(bsub(BONE, normalizedWeight), swapFee);
        uint256 tokenAmountInAfterFee = bmul(tokenAmountIn, bsub(BONE, zaz));

        uint256 newTokenBalanceIn = badd(tokenBalanceIn, tokenAmountInAfterFee);
        uint256 tokenInRatio = bdiv(newTokenBalanceIn, tokenBalanceIn);

        // uint newPoolSupply = (ratioTi ^ weightTi) * poolSupply;
        uint256 poolRatio = bpow(tokenInRatio, normalizedWeight);
        uint256 newPoolSupply = bmul(poolRatio, poolSupply);
        poolAmountOut = bsub(newPoolSupply, poolSupply);
        return poolAmountOut;
    }

    /**********************************************************************************************
    // calcSingleInGivenPoolOut                                                                  //
    // tAi = tokenAmountIn              //(pS + pAo)\     /    1    \\                           //
    // pS = poolSupply                 || ---------  | ^ | --------- || * bI - bI                //
    // pAo = poolAmountOut              \\    pS    /     \(wI / tW)//                           //
    // bI = balanceIn          tAi =  --------------------------------------------               //
    // wI = weightIn                              /      wI  \                                   //
    // tW = totalWeight                          |  1 - ----  |  * sF                            //
    // sF = swapFee                               \      tW  /                                   //
    **********************************************************************************************/
    function calcSingleInGivenPoolOut(
        uint256 tokenBalanceIn,
        uint256 tokenWeightIn,
        uint256 poolSupply,
        uint256 totalWeight,
        uint256 poolAmountOut,
        uint256 swapFee
    ) public pure returns (uint256 tokenAmountIn) {
        uint256 normalizedWeight = bdiv(tokenWeightIn, totalWeight);
        uint256 newPoolSupply = badd(poolSupply, poolAmountOut);
        uint256 poolRatio = bdiv(newPoolSupply, poolSupply);

        //uint newBalTi = poolRatio^(1/weightTi) * balTi;
        uint256 boo = bdiv(BONE, normalizedWeight);
        uint256 tokenInRatio = bpow(poolRatio, boo);
        uint256 newTokenBalanceIn = bmul(tokenInRatio, tokenBalanceIn);
        uint256 tokenAmountInAfterFee = bsub(newTokenBalanceIn, tokenBalanceIn);
        // Do reverse order of fees charged in joinswap_ExternAmountIn, this way
        //     ``` pAo == joinswap_ExternAmountIn(Ti, joinswap_PoolAmountOut(pAo, Ti)) ```
        //uint tAi = tAiAfterFee / (1 - (1-weightTi) * swapFee) ;
        uint256 zar = bmul(bsub(BONE, normalizedWeight), swapFee);
        tokenAmountIn = bdiv(tokenAmountInAfterFee, bsub(BONE, zar));
        return tokenAmountIn;
    }

    /**********************************************************************************************
    // calcSingleOutGivenPoolIn                                                                  //
    // tAo = tokenAmountOut            /      /                                             \\   //
    // bO = tokenBalanceOut           /      // pS - (pAi * (1 - eF)) \     /    1    \      \\  //
    // pAi = poolAmountIn            | bO - || ----------------------- | ^ | --------- | * b0 || //
    // ps = poolSupply                \      \\          pS           /     \(wO / tW)/      //  //
    // wI = tokenWeightIn      tAo =   \      \                                             //   //
    // tW = totalWeight                    /     /      wO \       \                             //
    // sF = swapFee                    *  | 1 - |  1 - ---- | * sF  |                            //
    // eF = exitFee                        \     \      tW /       /                             //
    **********************************************************************************************/
    function calcSingleOutGivenPoolIn(
        uint256 tokenBalanceOut,
        uint256 tokenWeightOut,
        uint256 poolSupply,
        uint256 totalWeight,
        uint256 poolAmountIn,
        uint256 swapFee
    ) public pure returns (uint256 tokenAmountOut) {
        uint256 normalizedWeight = bdiv(tokenWeightOut, totalWeight);
        // charge exit fee on the pool token side
        // pAiAfterExitFee = pAi*(1-exitFee)
        uint256 poolAmountInAfterExitFee = bmul(poolAmountIn, bsub(BONE, EXIT_FEE));
        uint256 newPoolSupply = bsub(poolSupply, poolAmountInAfterExitFee);
        uint256 poolRatio = bdiv(newPoolSupply, poolSupply);

        // newBalTo = poolRatio^(1/weightTo) * balTo;
        uint256 tokenOutRatio = bpow(poolRatio, bdiv(BONE, normalizedWeight));
        uint256 newTokenBalanceOut = bmul(tokenOutRatio, tokenBalanceOut);

        uint256 tokenAmountOutBeforeSwapFee = bsub(tokenBalanceOut, newTokenBalanceOut);

        // charge swap fee on the output token side
        //uint tAo = tAoBeforeSwapFee * (1 - (1-weightTo) * swapFee)
        uint256 zaz = bmul(bsub(BONE, normalizedWeight), swapFee);
        tokenAmountOut = bmul(tokenAmountOutBeforeSwapFee, bsub(BONE, zaz));
        return tokenAmountOut;
    }

    /**********************************************************************************************
    // calcPoolInGivenSingleOut                                                                  //
    // pAi = poolAmountIn               // /               tAo             \\     / wO \     \   //
    // bO = tokenBalanceOut            // | bO - -------------------------- |\   | ---- |     \  //
    // tAo = tokenAmountOut      pS - ||   \     1 - ((1 - (tO / tW)) * sF)/  | ^ \ tW /  * pS | //
    // ps = poolSupply                 \\ -----------------------------------/                /  //
    // wO = tokenWeightOut  pAi =       \\               bO                 /                /   //
    // tW = totalWeight           -------------------------------------------------------------  //
    // sF = swapFee                                        ( 1 - eF )                            //
    // eF = exitFee                                                                              //
    **********************************************************************************************/
    function calcPoolInGivenSingleOut(
        uint256 tokenBalanceOut,
        uint256 tokenWeightOut,
        uint256 poolSupply,
        uint256 totalWeight,
        uint256 tokenAmountOut,
        uint256 swapFee
    ) public pure returns (uint256 poolAmountIn) {
        // charge swap fee on the output token side
        uint256 normalizedWeight = bdiv(tokenWeightOut, totalWeight);
        //uint tAoBeforeSwapFee = tAo / (1 - (1-weightTo) * swapFee) ;
        uint256 zoo = bsub(BONE, normalizedWeight);
        uint256 zar = bmul(zoo, swapFee);
        uint256 tokenAmountOutBeforeSwapFee = bdiv(tokenAmountOut, bsub(BONE, zar));

        uint256 newTokenBalanceOut = bsub(tokenBalanceOut, tokenAmountOutBeforeSwapFee);
        uint256 tokenOutRatio = bdiv(newTokenBalanceOut, tokenBalanceOut);

        //uint newPoolSupply = (ratioTo ^ weightTo) * poolSupply;
        uint256 poolRatio = bpow(tokenOutRatio, normalizedWeight);
        uint256 newPoolSupply = bmul(poolRatio, poolSupply);
        uint256 poolAmountInAfterExitFee = bsub(poolSupply, newPoolSupply);

        // charge exit fee on the pool token side
        // pAi = pAiAfterExitFee/(1-exitFee)
        poolAmountIn = bdiv(poolAmountInAfterExitFee, bsub(BONE, EXIT_FEE));
        return poolAmountIn;
    }
}

// File: contracts/balancer/BNum.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

import "./BConst.sol";

// Core contract; can't be changed. So disable solhint (reminder for v2)

/* solhint-disable private-vars-leading-underscore */

contract BNum is BConst {
    function btoi(uint256 a) internal pure returns (uint256) {
        return a / BONE;
    }

    function bfloor(uint256 a) internal pure returns (uint256) {
        return btoi(a) * BONE;
    }

    function badd(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ERR_ADD_OVERFLOW");
        return c;
    }

    function bsub(uint256 a, uint256 b) internal pure returns (uint256) {
        (uint256 c, bool flag) = bsubSign(a, b);
        require(!flag, "ERR_SUB_UNDERFLOW");
        return c;
    }

    function bsubSign(uint256 a, uint256 b) internal pure returns (uint256, bool) {
        if (a >= b) {
            return (a - b, false);
        } else {
            return (b - a, true);
        }
    }

    function bmul(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c0 = a * b;
        require(a == 0 || c0 / a == b, "ERR_MUL_OVERFLOW");
        uint256 c1 = c0 + (BONE / 2);
        require(c1 >= c0, "ERR_MUL_OVERFLOW");
        uint256 c2 = c1 / BONE;
        return c2;
    }

    function bdiv(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "ERR_DIV_ZERO");
        uint256 c0 = a * BONE;
        require(a == 0 || c0 / a == BONE, "ERR_DIV_INTERNAL"); // bmul overflow
        uint256 c1 = c0 + (b / 2);
        require(c1 >= c0, "ERR_DIV_INTERNAL"); //  badd require
        uint256 c2 = c1 / b;
        return c2;
    }

    // DSMath.wpow
    function bpowi(uint256 a, uint256 n) internal pure returns (uint256) {
        uint256 z = n % 2 != 0 ? a : BONE;

        for (n /= 2; n != 0; n /= 2) {
            a = bmul(a, a);

            if (n % 2 != 0) {
                z = bmul(z, a);
            }
        }
        return z;
    }

    // Compute b^(e.w) by splitting it into (b^e)*(b^0.w).
    // Use `bpowi` for `b^e` and `bpowK` for k iterations
    // of approximation of b^0.w
    function bpow(uint256 base, uint256 exp) internal pure returns (uint256) {
        require(base >= MIN_BPOW_BASE, "ERR_BPOW_BASE_TOO_LOW");
        require(base <= MAX_BPOW_BASE, "ERR_BPOW_BASE_TOO_HIGH");

        uint256 whole = bfloor(exp);
        uint256 remain = bsub(exp, whole);

        uint256 wholePow = bpowi(base, btoi(whole));

        if (remain == 0) {
            return wholePow;
        }

        uint256 partialResult = bpowApprox(base, remain, BPOW_PRECISION);
        return bmul(wholePow, partialResult);
    }

    function bpowApprox(
        uint256 base,
        uint256 exp,
        uint256 precision
    ) internal pure returns (uint256) {
        // term 0:
        uint256 a = exp;
        (uint256 x, bool xneg) = bsubSign(base, BONE);
        uint256 term = BONE;
        uint256 sum = term;
        bool negative = false;

        // term(k) = numer / denom
        //         = (product(a - i - 1, i=1-->k) * x^k) / (k!)
        // each iteration, multiply previous term by (a-(k-1)) * x / k
        // continue until term is less than precision
        for (uint256 i = 1; term >= precision; i++) {
            uint256 bigK = i * BONE;
            (uint256 c, bool cneg) = bsubSign(a, bsub(bigK, BONE));
            term = bmul(term, bmul(c, x));
            term = bdiv(term, bigK);
            if (term == 0) break;

            if (xneg) negative = !negative;
            if (cneg) negative = !negative;
            if (negative) {
                sum = bsub(sum, term);
            } else {
                sum = badd(sum, term);
            }
        }

        return sum;
    }
}

// File: contracts/balancer/PCToken.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.6.12;

// Imports

import "./libraries/BalancerSafeMath.sol";
import "./interfaces/IERC20.sol";

// Contracts

/* solhint-disable func-order */

/**
 * @author Balancer Labs
 * @title Highly opinionated token implementation
 */
contract PCToken is IERC20 {
    using BalancerSafeMath for uint256;

    // State variables
    string public constant NAME = "Balancer Smart Pool";
    uint8 public constant DECIMALS = 18;

    // No leading underscore per naming convention (non-private)
    // Cannot call totalSupply (name conflict)
    // solhint-disable-next-line private-vars-leading-underscore
    uint256 internal varTotalSupply;

    mapping(address => uint256) private _balance;
    mapping(address => mapping(address => uint256)) private _allowance;

    string private _symbol;
    string private _name;

    // Event declarations

    // See definitions above; must be redeclared to be emitted from this contract
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

    // Function declarations

    /**
     * @notice Base token constructor
     * @param tokenSymbol - the token symbol
     */
    constructor(string memory tokenSymbol, string memory tokenName) public {
        _symbol = tokenSymbol;
        _name = tokenName;
    }

    // External functions

    /**
     * @notice Getter for allowance: amount spender will be allowed to spend on behalf of owner
     * @param owner - owner of the tokens
     * @param spender - entity allowed to spend the tokens
     * @return uint - remaining amount spender is allowed to transfer
     */
    function allowance(address owner, address spender) external view override returns (uint256) {
        return _allowance[owner][spender];
    }

    /**
     * @notice Getter for current account balance
     * @param account - address we're checking the balance of
     * @return uint - token balance in the account
     */
    function balanceOf(address account) external view override returns (uint256) {
        return _balance[account];
    }

    /**
     * @notice Approve owner (sender) to spend a certain amount
     * @dev emits an Approval event
     * @param spender - entity the owner (sender) is approving to spend his tokens
     * @param amount - number of tokens being approved
     * @return bool - result of the approval (will always be true if it doesn't revert)
     */
    function approve(address spender, uint256 amount) external override returns (bool) {
        /* In addition to the increase/decreaseApproval functions, could
           avoid the "approval race condition" by only allowing calls to approve
           when the current approval amount is 0
        
           require(_allowance[msg.sender][spender] == 0, "ERR_RACE_CONDITION");

           Some token contracts (e.g., KNC), already revert if you call approve 
           on a non-zero allocation. To deal with these, we use the SafeApprove library
           and safeApprove function when adding tokens to the pool.
        */

        _allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    /**
     * @notice Increase the amount the spender is allowed to spend on behalf of the owner (sender)
     * @dev emits an Approval event
     * @param spender - entity the owner (sender) is approving to spend his tokens
     * @param amount - number of tokens being approved
     * @return bool - result of the approval (will always be true if it doesn't revert)
     */
    function increaseApproval(address spender, uint256 amount) external returns (bool) {
        _allowance[msg.sender][spender] = BalancerSafeMath.badd(_allowance[msg.sender][spender], amount);

        emit Approval(msg.sender, spender, _allowance[msg.sender][spender]);

        return true;
    }

    /**
     * @notice Decrease the amount the spender is allowed to spend on behalf of the owner (sender)
     * @dev emits an Approval event
     * @dev If you try to decrease it below the current limit, it's just set to zero (not an error)
     * @param spender - entity the owner (sender) is approving to spend his tokens
     * @param amount - number of tokens being approved
     * @return bool - result of the approval (will always be true if it doesn't revert)
     */
    function decreaseApproval(address spender, uint256 amount) external returns (bool) {
        uint256 oldValue = _allowance[msg.sender][spender];
        // Gas optimization - if amount == oldValue (or is larger), set to zero immediately
        if (amount >= oldValue) {
            _allowance[msg.sender][spender] = 0;
        } else {
            _allowance[msg.sender][spender] = BalancerSafeMath.bsub(oldValue, amount);
        }

        emit Approval(msg.sender, spender, _allowance[msg.sender][spender]);

        return true;
    }

    /**
     * @notice Transfer the given amount from sender (caller) to recipient
     * @dev _move emits a Transfer event if successful
     * @param recipient - entity receiving the tokens
     * @param amount - number of tokens being transferred
     * @return bool - result of the transfer (will always be true if it doesn't revert)
     */
    function transfer(address recipient, uint256 amount) external override returns (bool) {
        require(recipient != address(0), "ERR_ZERO_ADDRESS");

        _move(msg.sender, recipient, amount);

        return true;
    }

    /**
     * @notice Transfer the given amount from sender to recipient
     * @dev _move emits a Transfer event if successful; may also emit an Approval event
     * @param sender - entity sending the tokens (must be caller or allowed to spend on behalf of caller)
     * @param recipient - recipient of the tokens
     * @param amount - number of tokens being transferred
     * @return bool - result of the transfer (will always be true if it doesn't revert)
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        require(recipient != address(0), "ERR_ZERO_ADDRESS");
        require(msg.sender == sender || amount <= _allowance[sender][msg.sender], "ERR_PCTOKEN_BAD_CALLER");

        _move(sender, recipient, amount);

        // memoize for gas optimization
        uint256 oldAllowance = _allowance[sender][msg.sender];

        // If the sender is not the caller, adjust the allowance by the amount transferred
        if (msg.sender != sender && oldAllowance != uint256(-1)) {
            _allowance[sender][msg.sender] = BalancerSafeMath.bsub(oldAllowance, amount);

            emit Approval(msg.sender, recipient, _allowance[sender][msg.sender]);
        }

        return true;
    }

    // public functions

    /**
     * @notice Getter for the total supply
     * @dev declared external for gas optimization
     * @return uint - total number of tokens in existence
     */
    function totalSupply() external view override returns (uint256) {
        return varTotalSupply;
    }

    // Public functions

    /**
     * @dev Returns the name of the token.
     *      We allow the user to set this name (as well as the symbol).
     *      Alternatives are 1) A fixed string (original design)
     *                       2) A fixed string plus the user-defined symbol
     *                          return string(abi.encodePacked(NAME, "-", _symbol));
     */
    function name() external view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() external view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() external pure returns (uint8) {
        return DECIMALS;
    }

    // internal functions

    // Mint an amount of new tokens, and add them to the balance (and total supply)
    // Emit a transfer amount from the null address to this contract
    function _mint(uint256 amount) internal virtual {
        _balance[address(this)] = BalancerSafeMath.badd(_balance[address(this)], amount);
        varTotalSupply = BalancerSafeMath.badd(varTotalSupply, amount);

        emit Transfer(address(0), address(this), amount);
    }

    // Burn an amount of new tokens, and subtract them from the balance (and total supply)
    // Emit a transfer amount from this contract to the null address
    function _burn(uint256 amount) internal virtual {
        // Can't burn more than we have
        // Remove require for gas optimization - bsub will revert on underflow
        // require(_balance[address(this)] >= amount, "ERR_INSUFFICIENT_BAL");

        _balance[address(this)] = BalancerSafeMath.bsub(_balance[address(this)], amount);
        varTotalSupply = BalancerSafeMath.bsub(varTotalSupply, amount);

        emit Transfer(address(this), address(0), amount);
    }

    // Transfer tokens from sender to recipient
    // Adjust balances, and emit a Transfer event
    function _move(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        // Can't send more than sender has
        // Remove require for gas optimization - bsub will revert on underflow
        // require(_balance[sender] >= amount, "ERR_INSUFFICIENT_BAL");

        _balance[sender] = BalancerSafeMath.bsub(_balance[sender], amount);
        _balance[recipient] = BalancerSafeMath.badd(_balance[recipient], amount);

        emit Transfer(sender, recipient, amount);
    }

    // Transfer from this contract to recipient
    // Emits a transfer event if successful
    function _push(address recipient, uint256 amount) internal {
        _move(address(this), recipient, amount);
    }

    // Transfer from recipient to this contract
    // Emits a transfer event if successful
    function _pull(address sender, uint256 amount) internal {
        _move(sender, address(this), amount);
    }
}

// File: contracts/balancer/BConst.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

import "./BColor.sol";

contract BConst is BBronze {
    uint256 public constant BONE = 10**18;

    uint256 public constant MIN_BOUND_TOKENS = 2;
    uint256 public constant MAX_BOUND_TOKENS = 8;

    uint256 public constant MIN_FEE = BONE / 10**6;
    uint256 public constant MAX_FEE = BONE / 10;
    uint256 public constant EXIT_FEE = 0;

    uint256 public constant MIN_WEIGHT = BONE;
    uint256 public constant MAX_WEIGHT = BONE * 50;
    uint256 public constant MAX_TOTAL_WEIGHT = BONE * 50;
    uint256 public constant MIN_BALANCE = BONE / 10**12;

    uint256 public constant INIT_POOL_SUPPLY = BONE * 100;

    uint256 public constant MIN_BPOW_BASE = 1 wei;
    uint256 public constant MAX_BPOW_BASE = (2 * BONE) - 1 wei;
    uint256 public constant BPOW_PRECISION = BONE / 10**10;

    uint256 public constant MAX_IN_RATIO = BONE / 2;
    uint256 public constant MAX_OUT_RATIO = (BONE / 3) + 1 wei;
}

// File: contracts/balancer/BColor.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.6.6;

// abstract contract BColor {
//     function getColor()
//         external view virtual
//         returns (bytes32);
// }

contract BBronze {
    function getColor() external pure returns (bytes32) {
        return bytes32("BRONZE");
    }
}

// File: contracts/balancer/libraries/BalancerSafeMath.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.6.12;

// Imports

import "./BalancerConstants.sol";

/**
 * @author Balancer Labs
 * @title SafeMath - wrap Solidity operators to prevent underflow/overflow
 * @dev badd and bsub are basically identical to OpenZeppelin SafeMath; mul/div have extra checks
 */
library BalancerSafeMath {
    /**
     * @notice Safe addition
     * @param a - first operand
     * @param b - second operand
     * @dev if we are adding b to a, the resulting sum must be greater than a
     * @return - sum of operands; throws if overflow
     */
    function badd(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "ERR_ADD_OVERFLOW");
        return c;
    }

    /**
     * @notice Safe unsigned subtraction
     * @param a - first operand
     * @param b - second operand
     * @dev Do a signed subtraction, and check that it produces a positive value
     *      (i.e., a - b is valid if b <= a)
     * @return - a - b; throws if underflow
     */
    function bsub(uint256 a, uint256 b) internal pure returns (uint256) {
        (uint256 c, bool negativeResult) = bsubSign(a, b);
        require(!negativeResult, "ERR_SUB_UNDERFLOW");
        return c;
    }

    /**
     * @notice Safe signed subtraction
     * @param a - first operand
     * @param b - second operand
     * @dev Do a signed subtraction
     * @return - difference between a and b, and a flag indicating a negative result
     *           (i.e., a - b if a is greater than or equal to b; otherwise b - a)
     */
    function bsubSign(uint256 a, uint256 b) internal pure returns (uint256, bool) {
        if (b <= a) {
            return (a - b, false);
        } else {
            return (b - a, true);
        }
    }

    /**
     * @notice Safe multiplication
     * @param a - first operand
     * @param b - second operand
     * @dev Multiply safely (and efficiently), rounding down
     * @return - product of operands; throws if overflow or rounding error
     */
    function bmul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization (see github.com/OpenZeppelin/openzeppelin-contracts/pull/522)
        if (a == 0) {
            return 0;
        }

        // Standard overflow check: a/a*b=b
        uint256 c0 = a * b;
        require(c0 / a == b, "ERR_MUL_OVERFLOW");

        // Round to 0 if x*y < BONE/2?
        uint256 c1 = c0 + (BalancerConstants.BONE / 2);
        require(c1 >= c0, "ERR_MUL_OVERFLOW");
        uint256 c2 = c1 / BalancerConstants.BONE;
        return c2;
    }

    /**
     * @notice Safe division
     * @param dividend - first operand
     * @param divisor - second operand
     * @dev Divide safely (and efficiently), rounding down
     * @return - quotient; throws if overflow or rounding error
     */
    function bdiv(uint256 dividend, uint256 divisor) internal pure returns (uint256) {
        require(divisor != 0, "ERR_DIV_ZERO");

        // Gas optimization
        if (dividend == 0) {
            return 0;
        }

        uint256 c0 = dividend * BalancerConstants.BONE;
        require(c0 / dividend == BalancerConstants.BONE, "ERR_DIV_INTERNAL"); // bmul overflow

        uint256 c1 = c0 + (divisor / 2);
        require(c1 >= c0, "ERR_DIV_INTERNAL"); //  badd require

        uint256 c2 = c1 / divisor;
        return c2;
    }

    /**
     * @notice Safe unsigned integer modulo
     * @dev Returns the remainder of dividing two unsigned integers.
     *      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).
     *
     * @param dividend - first operand
     * @param divisor - second operand -- cannot be zero
     * @return - quotient; throws if overflow or rounding error
     */
    function bmod(uint256 dividend, uint256 divisor) internal pure returns (uint256) {
        require(divisor != 0, "ERR_MODULO_BY_ZERO");

        return dividend % divisor;
    }

    /**
     * @notice Safe unsigned integer max
     * @dev Returns the greater of the two input values
     *
     * @param a - first operand
     * @param b - second operand
     * @return - the maximum of a and b
     */
    function bmax(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @notice Safe unsigned integer min
     * @dev returns b, if b < a; otherwise returns a
     *
     * @param a - first operand
     * @param b - second operand
     * @return - the lesser of the two input values
     */
    function bmin(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @notice Safe unsigned integer average
     * @dev Guard against (a+b) overflow by dividing each operand separately
     *
     * @param a - first operand
     * @param b - second operand
     * @return - the average of the two values
     */
    function baverage(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + (((a % 2) + (b % 2)) / 2);
    }

    /**
     * @notice Babylonian square root implementation
     * @dev (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
     * @param y - operand
     * @return z - the square root result
     */
    function sqrt(uint256 y) internal pure returns (uint256 z) {
        if (y > 3) {
            z = y;
            uint256 x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/balancer/interfaces/IERC20.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.6.12;

// Interface declarations

/* solhint-disable func-order */

interface IERC20 {
    // 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);

    // 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);

    // Returns the amount of tokens in existence
    function totalSupply() external view returns (uint256);

    // Returns the amount of tokens owned by account
    function balanceOf(address account) external view returns (uint256);

    // 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);

    // Sets amount as the allowance of spender over the caller’s tokens
    // Returns a boolean value indicating whether the operation succeeded
    // Emits an Approval event.
    function approve(address spender, uint256 amount) external returns (bool);

    // 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);

    // 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);
}

// File: contracts/balancer/libraries/BalancerConstants.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.6.12;

/**
 * @author Balancer Labs
 * @title Put all the constants in one place
 */

library BalancerConstants {
    // State variables (must be constant in a library)

    // B "ONE" - all math is in the "realm" of 10 ** 18;
    // where numeric 1 = 10 ** 18
    uint256 public constant BONE = 10**18;
    uint256 public constant MIN_WEIGHT = BONE;
    uint256 public constant MAX_WEIGHT = BONE * 50;
    uint256 public constant MAX_TOTAL_WEIGHT = BONE * 50;
    uint256 public constant MIN_BALANCE = BONE / 10**6;
    uint256 public constant MAX_BALANCE = BONE * 10**12;
    uint256 public constant MIN_POOL_SUPPLY = BONE * 100;
    uint256 public constant MAX_POOL_SUPPLY = BONE * 10**9;
    uint256 public constant MIN_FEE = BONE / 10**6;
    uint256 public constant MAX_FEE = BONE / 10;
    // EXIT_FEE must always be zero, or ConfigurableRightsPool._pushUnderlying will fail
    uint256 public constant EXIT_FEE = 0;
    uint256 public constant MAX_IN_RATIO = BONE / 2;
    uint256 public constant MAX_OUT_RATIO = (BONE / 3) + 1 wei;
    // Must match BConst.MIN_BOUND_TOKENS and BConst.MAX_BOUND_TOKENS
    uint256 public constant MIN_ASSET_LIMIT = 2;
    uint256 public constant MAX_ASSET_LIMIT = 8;
    uint256 public constant MAX_UINT = uint256(-1);
}