// SPDX-License-Identifier: MIT

pragma solidity ^0.6.12;


// 
/**
 * @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);
}

// 
/**
 * @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;
    }
}

// 
/**
 * @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);
            }
        }
    }
}

// 
/**
 * @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");
        }
    }
}

// 
interface ICurveFi {
    function get_virtual_price() external view returns (uint256);

    function add_liquidity(
        // sBTC pool
        uint256[3] calldata amounts,
        uint256 min_mint_amount
    ) external;

    function add_liquidity(
        // bUSD pool
        uint256[4] calldata amounts,
        uint256 min_mint_amount
    ) external;

    function remove_liquidity_imbalance(uint256[4] calldata amounts, uint256 max_burn_amount) external;

    function remove_liquidity(uint256 _amount, uint256[4] calldata amounts) external;

    function exchange(
        int128 from,
        int128 to,
        uint256 _from_amount,
        uint256 _min_to_amount
    ) external;
}

interface ICurveDeposit {
    function get_virtual_price() external view returns (uint256);

    function add_liquidity(
        // renBTC pool
        uint256[2] calldata amounts,
        uint256 min_mint_amount
    ) external;

    function add_liquidity(
        // sBTC pool
        uint256[3] calldata amounts,
        uint256 min_mint_amount
    ) external;

    function add_liquidity(
        // bUSD pool
        uint256[4] calldata amounts,
        uint256 min_mint_amount
    ) external;

    function remove_liquidity_one_coin(uint256 _amount, int128 _i, uint256 _min_uamount) external;

    // function remove_liquidity_one_coin(uint256 _amount, int128 _i, uint256 _min_uamount, bool _donate_dust) external;

    function remove_liquidity(uint256 _amount, uint256[4] calldata amounts) external;

    function exchange(
        int128 from,
        int128 to,
        uint256 _from_amount,
        uint256 _min_to_amount
    ) external;

    function calc_withdraw_one_coin(uint256 _amount, int128 _index) external view returns(uint256);
}

// 
interface Gauge {
    function deposit(uint256) external;

    function balanceOf(address) external view returns (uint256);

    function withdraw(uint256) external;
}

// 
interface Uni {
    function  swapExactTokensForTokens(
        uint256,
        uint256,
        address[] calldata,
        address,
        uint256
    ) external;

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
}

interface IController {
    function withdraw(address, uint256) external;

    function balanceOf(address) external view returns (uint256);

    function earn(address, uint256) external;

    function want(address) external view returns (address);

    function rewards() external view returns (address);

    function vaults(address) external view returns (address);
}

// 
interface Mintr {
    function mint(address) external;
}

// 
contract StrategyCurve3TokenPool {
    using SafeERC20 for IERC20;
    using Address for address;
    using SafeMath for uint256;

    uint256 public constant N_COINS = 3;
    uint256 public immutable WANT_COIN_INDEX;
    address public immutable want;
    address public immutable crvLP;
    address public immutable curveDeposit;
    address public immutable gauge;

    address public immutable mintr;
    address public immutable crv;
    address public immutable uni;
    // used for crv <> weth <> dai route
    address public immutable weth;
    string private name;

    // DAI, USDC, USDT, TUSD
    address[N_COINS] public coins;
    uint256[N_COINS] public ZEROS = [uint256(0), uint256(0), uint256(0)];

    uint256 public performanceFee = 500;
    uint256 public immutable performanceMax = 10000;

    uint256 public withdrawalFee = 0;
    uint256 public immutable withdrawalMax = 10000;

    address public governance;
    address public controller;
    address public timelock;

    constructor
    (
        address _controller,
        string memory _name,
        uint256 _wantCoinIndex,
        address[N_COINS] memory _coins,
        address _curveDeposit,
        address _gauge,
        address _crvLP,
        address _crv,
        address _uni,
        address _mintr,
        address _weth,
        address _timelock
    )
    public
    {
        governance = msg.sender;
        controller = _controller;
        name = _name;
        WANT_COIN_INDEX = _wantCoinIndex;
        want = _coins[_wantCoinIndex];
        coins = _coins;
        curveDeposit = _curveDeposit;
        gauge = _gauge;
        crvLP = _crvLP;
        crv = _crv;
        uni = _uni;
        mintr = _mintr;
        weth = _weth;
        timelock = _timelock;
    }

    function getName() external view returns (string memory) {
        return name;
    }

    function setWithdrawalFee(uint256 _withdrawalFee) external {
        require(msg.sender == governance, "!governance");
        require(_withdrawalFee < withdrawalMax, "inappropriate withdraw fee");
        withdrawalFee = _withdrawalFee;
    }

    function setPerformanceFee(uint256 _performanceFee) external {
        require(msg.sender == governance, "!governance");
        require(_performanceFee < performanceMax, "inappropriate performance fee");
        performanceFee = _performanceFee;
    }

    function deposit() public {
        _deposit(WANT_COIN_INDEX);
    }

    function _deposit(uint256 _coinIndex) internal {
        require(_coinIndex < N_COINS, "index exceeded bound");
        address coinAddr = coins[_coinIndex];
        uint256 wantAmount = IERC20(coinAddr).balanceOf(address(this));
        if (wantAmount > 0) {
            IERC20(coinAddr).safeApprove(curveDeposit, 0);
            IERC20(coinAddr).safeApprove(curveDeposit, wantAmount);
            uint256[N_COINS] memory amounts = ZEROS;
            amounts[_coinIndex] = wantAmount;
            // TODO: add minimun mint amount if required
            ICurveDeposit(curveDeposit).add_liquidity(amounts, 0);
        }
        uint256 crvLPAmount = IERC20(crvLP).balanceOf(address(this));
        if (crvLPAmount > 0) {
            IERC20(crvLP).safeApprove(gauge, 0);
            IERC20(crvLP).safeApprove(gauge, crvLPAmount);
            Gauge(gauge).deposit(crvLPAmount);
        }
    }

    // Withdraw all funds, normally used when migrating strategies
    function withdrawAll() external returns (uint256 balance) {
        require(msg.sender == controller, "!controller");
        uint256 _amount = Gauge(gauge).balanceOf(address(this));
        Gauge(gauge).withdraw(_amount);
        IERC20(crvLP).safeApprove(curveDeposit, 0);
        IERC20(crvLP).safeApprove(curveDeposit, _amount);
        // TODO: add minimun mint amount if required
        ICurveDeposit(curveDeposit).remove_liquidity_one_coin(_amount, int128(WANT_COIN_INDEX), 0);

        balance = IERC20(want).balanceOf(address(this));

        address _vault = IController(controller).vaults(address(want));
        require(_vault != address(0), "!vault");
        // additional protection so we don't burn the funds
        IERC20(want).safeTransfer(_vault, balance);
    }

    function withdraw(uint256 _amount) external {
        require(msg.sender == controller, "!controller");
        uint256 _balance = IERC20(want).balanceOf(address(this));
        if (_balance < _amount) {
            _withdrawSome(_amount.sub(_balance));
            _amount = IERC20(want).balanceOf(address(this));
        }
        uint256 _fee = _amount.mul(withdrawalFee).div(withdrawalMax);
        IERC20(want).safeTransfer(IController(controller).rewards(), _fee);
        address _vault = IController(controller).vaults(address(want));
        require(_vault != address(0), "!vault");
        // additional protection so we don't burn the funds

        IERC20(want).safeTransfer(_vault, _amount.sub(_fee));
    }

    function _withdrawSome(uint256 _amount) internal {
        uint256 rate = ICurveDeposit(curveDeposit).calc_withdraw_one_coin(10**18, int128(WANT_COIN_INDEX));
        _amount = _amount.mul(10**18).div(rate);

        if (_amount > balanceOfGauge()) {
            _amount = balanceOfGauge();
        }

        Gauge(gauge).withdraw(_amount);
        IERC20(crvLP).safeApprove(curveDeposit, 0);
        IERC20(crvLP).safeApprove(curveDeposit, _amount);
        // TODO: add minimun mint amount if required
        ICurveDeposit(curveDeposit).remove_liquidity_one_coin(_amount, int128(WANT_COIN_INDEX), 0);
    }

    // Controller only function for creating additional rewards from dust
    function withdraw(IERC20 _asset) external returns (uint256 balance) {
        require(msg.sender == controller, "!controller");
        for (uint i = 0; i < N_COINS; ++i) {
            require(coins[i] != address(_asset), "internal token");
        }
        require(crv != address(_asset), "crv");
        require(crvLP != address(_asset), "crvLP");
        balance = _asset.balanceOf(address(this));
        _asset.safeTransfer(controller, balance);
    }

    function harvest(uint _coinIndex) public {
        require(_coinIndex < N_COINS, "index exceeded bound");
        Mintr(mintr).mint(gauge);
        address harvestingCoin = coins[_coinIndex];
        uint256 _crv = IERC20(crv).balanceOf(address(this));
        if (_crv > 0) {

            IERC20(crv).safeApprove(uni, 0);
            IERC20(crv).safeApprove(uni, _crv);

            address[] memory path = new address[](3);
            path[0] = crv;
            path[1] = weth;
            path[2] = harvestingCoin;
            // TODO: add minimun mint amount if required
            Uni(uni).swapExactTokensForTokens(_crv, uint256(0), path, address(this), now.add(1800));
        }
        uint256 harvestAmount = IERC20(harvestingCoin).balanceOf(address(this));
        if (harvestAmount > 0) {
            uint256 _fee = harvestAmount.mul(performanceFee).div(performanceMax);
            IERC20(harvestingCoin).safeTransfer(IController(controller).rewards(), _fee);
            _deposit(_coinIndex);
        }
    }

    function balanceOfWant() public view returns (uint256) {
        return IERC20(want).balanceOf(address(this));
    }

    function balanceOfGauge() public view returns (uint256) {
        return Gauge(gauge).balanceOf(address(this));
    }

    function balanceOfPool() public view returns (uint256) {
        uint256 gaugeBalance = balanceOfGauge();
        // NOTE: this is for curve 3 pool only, since calc_withdraw_one_coin
        // would raise error when input 0 amount
        if (gaugeBalance == 0) {
            return 0;
        }
        // portfolio virtual price (for calculating profit) scaled up by 1e18
        uint256 price = ICurveDeposit(curveDeposit).get_virtual_price();
        uint256 _amount = gaugeBalance.mul(price).div(1e18);
        return convertToCoinAmount(uint128(WANT_COIN_INDEX), _amount);
    }

    function convertToCoinAmount(uint128 _index, uint256 _amount) public view returns (uint256){
        if (_index == 0) {
            return _amount;
        } else if (_index == 1) {
            //usdc decmials is 6
            return _amount.div(1e12);
        }
        //usdt decmials is 6
        return _amount.div(1e12);

    }


    function balanceOf() public view returns (uint256) {
        return balanceOfWant().add(balanceOfPool());
    }

    function setGovernance(address _governance) external {
        require(msg.sender == timelock, "!timelock");
        governance = _governance;
    }

    function setController(address _controller) external {
        require(msg.sender == timelock, "!timelock");
        controller = _controller;
    }

    function setTimelock(address _timelock) public {
        require(msg.sender == timelock, "!timelock");
        timelock = _timelock;
    }
}