// File: contracts/v3/Vault.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/GSN/Context.sol";

import "./interfaces/IManager.sol";
import "./interfaces/IController.sol";
import "./interfaces/IConverter.sol";
import "./interfaces/IVault.sol";
import "./interfaces/IVaultToken.sol";
import "./interfaces/ExtendedIERC20.sol";

/**
 * @title Vault
 * @notice The vault is where users deposit and withdraw
 * like-kind assets that have been added by governance.
 */
contract Vault is IVault {
    using Address for address;
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    uint256 public constant MAX = 10000;

    IManager public immutable override manager;
    IERC20 public immutable token;
    IVaultToken public immutable vaultToken;

    // Strategist-updated variables
    address public override gauge;
    uint256 public min;
    uint256 public totalDepositCap;

    event Deposit(address indexed account, uint256 amount);
    event Withdraw(address indexed account, uint256 amount);
    event Earn(address indexed token, uint256 amount);

    /**
     * @param _depositToken The address of the deposit token of the vault
     * @param _vaultToken The address of the share token for the vault
     * @param _manager The address of the vault manager contract
     */
    constructor(
        address _depositToken,
        address _vaultToken,
        address _manager
    )
        public
    {
        manager = IManager(_manager);
        token = IERC20(_depositToken);
        vaultToken = IVaultToken(_vaultToken);
        min = 9500;
        totalDepositCap = 10000000 ether;
    }

    /**
     * STRATEGIST-ONLY FUNCTIONS
     */

    /**
     * @notice Sets the value of this vault's gauge
     * @dev Allow to be unset with the zero address
     * @param _gauge The address of the gauge
     */
    function setGauge(
        address _gauge
    )
        external
        notHalted
        onlyStrategist
    {
        gauge = _gauge;
    }

    /**
     * @notice Sets the value for min
     * @dev min is the minimum percent of funds to keep small withdrawals cheap
     * @param _min The new min value
     */
    function setMin(
        uint256 _min
    )
        external
        notHalted
        onlyStrategist
    {
        require(_min <= MAX, "!_min");
        min = _min;
    }

    /**
     * @notice Sets the value for the totalDepositCap
     * @dev totalDepositCap is the maximum amount of value that can be deposited
     * to the metavault at a time
     * @param _totalDepositCap The new totalDepositCap value
     */
    function setTotalDepositCap(
        uint256 _totalDepositCap
    )
        external
        notHalted
        onlyStrategist
    {
        totalDepositCap = _totalDepositCap;
    }

    /**
     * HARVESTER-ONLY FUNCTIONS
     */

    /**
     * @notice Sends accrued 3CRV tokens on the metavault to the controller to be deposited to strategies
     */
    function earn(
        address _strategy
    )
        external
        override
        notHalted
        onlyHarvester
    {
        require(manager.allowedStrategies(_strategy), "!_strategy");
        IController _controller = IController(manager.controllers(address(this)));
        if (_controller.investEnabled()) {
            uint256 _balance = available();
            token.safeTransfer(address(_controller), _balance);
            _controller.earn(_strategy, address(token), _balance);
            emit Earn(address(token), _balance);
        }
    }

    /**
     * USER-FACING FUNCTIONS
     */

    /**
     * @notice Deposits the given token into the vault
     * @param _amount The amount of tokens to deposit
     */
     function deposit(
        uint256 _amount
     )
        public
        override
        notHalted
        returns (uint256 _shares)
    {
        require(_amount > 0, "!_amount");

        uint256 _balance = balance();

        uint256 _before = token.balanceOf(address(this));
        token.safeTransferFrom(msg.sender, address(this), _amount);
        _amount = token.balanceOf(address(this)).sub(_before);
        uint256 _supply = IERC20(address(vaultToken)).totalSupply();

        _amount = _normalizeDecimals(_amount);

        if (_supply > 0) {
            _amount = (_amount.mul(_supply)).div(_balance);
        }

        _shares = _amount;

        require(_shares > 0, "shares=0");
        require(_supply.add(_shares) <= totalDepositCap, ">totalDepositCap");
        vaultToken.mint(msg.sender, _shares);
        emit Deposit(msg.sender, _shares);
    }

    /**
     * @notice Withdraws an amount of shares to a given output token
     * @param _shares The amount of shares to withdraw
     */
    function withdraw(
        uint256 _shares
    )
        public
        override
    {
        uint256 _amount = (balance().mul(_shares)).div(IERC20(address(vaultToken)).totalSupply());
        vaultToken.burn(msg.sender, _shares);

        uint256 _withdrawalProtectionFee = manager.withdrawalProtectionFee();
        if (_withdrawalProtectionFee > 0) {
            uint256 _withdrawalProtection = _amount.mul(_withdrawalProtectionFee).div(MAX);
            _amount = _amount.sub(_withdrawalProtection);
        }

        uint256 _balance = token.balanceOf(address(this));
        if (_balance < _amount) {
            IController _controller = IController(manager.controllers(address(this)));
            uint256 _toWithdraw = _amount.sub(_balance);
            if (_controller.strategies() > 0) {
                _controller.withdraw(address(token), _toWithdraw);
            }
            uint256 _after = token.balanceOf(address(this));
            uint256 _diff = _after.sub(_balance);
            if (_diff < _toWithdraw) {
                _amount = _after;
            }
        }

        token.safeTransfer(msg.sender, _amount);
        emit Withdraw(msg.sender, _amount);
    }

    /**
     * @notice Withdraw the entire balance for an account
     */
    function withdrawAll()
        external
        override
    {
        withdraw(IERC20(address(vaultToken)).balanceOf(msg.sender));
    }

    /**
     * VIEWS
     */

    /**
     * @notice Returns the amount of tokens available to be sent to strategies
     * @dev Custom logic in here for how much the vault allows to be borrowed
     * @dev Sets minimum required on-hand to keep small withdrawals cheap
     */
    function available()
        public
        view
        override
        returns (uint256)
    {
        return token.balanceOf(address(this)).mul(min).div(MAX);
    }

    /**
     * @notice Returns the total balance of the vault, including strategies
     */
    function balance()
        public
        view
        override
        returns (uint256 _balance)
    {
        return balanceOfThis().add(_normalizeDecimals(IController(manager.controllers(address(this))).balanceOf()));
    }

    /**
     * @notice Returns the balance of allowed tokens present on the vault only
     */
    function balanceOfThis()
        public
        view
        returns (uint256)
    {
        return _normalizeDecimals(token.balanceOf(address(this)));
    }

    /**
     * @notice Returns the rate of vault shares
     */
    function getPricePerFullShare()
        external
        view
        override
        returns (uint256)
    {
        uint256 _supply = IERC20(address(vaultToken)).totalSupply();
        if (_supply > 0) {
            return balance().mul(1e18).div(_supply);
        } else {
            return balance();
        }
    }

    /**
     * @notice Returns the deposit token for the vault
     */
    function getToken()
        public
        view
        override
        returns (address)
    {
        return address(token);
    }

    function getLPToken()
        external
        view
        override
        returns (address)
    {
        return address(vaultToken);
    }

    /**
     * @notice Returns the fee for withdrawing the given amount
     * @param _amount The amount to withdraw
     */
    function withdrawFee(
        uint256 _amount
    )
        external
        view
        override
        returns (uint256)
    {
        return manager.withdrawalProtectionFee().mul(_amount).div(MAX);
    }

    function _normalizeDecimals(
        uint256 _amount
    )
        internal
        view
        returns (uint256)
    {
        uint256 _decimals = uint256(ExtendedIERC20(address(token)).decimals());
        if (_decimals < 18) {
            _amount = _amount.mul(10**(18-_decimals));
        }
        return _amount;
    }

    /**
     * MODIFIERS
     */

    modifier notHalted() {
        require(!manager.halted(), "halted");
        _;
    }

    modifier onlyHarvester() {
        require(msg.sender == manager.harvester(), "!harvester");
        _;
    }

    modifier onlyStrategist() {
        require(msg.sender == manager.strategist(), "!strategist");
        _;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/math/SafeMath.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @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) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @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) {
        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, reverting 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) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting 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) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * 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);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * 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);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.2 <0.8.0;

/**
 * @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 on 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");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "./IERC20.sol";
import "../../math/SafeMath.sol";
import "../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: @openzeppelin/contracts/GSN/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

import "../utils/Context.sol";

// File: contracts/v3/interfaces/IManager.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

interface IManager {
    function addVault(address) external;
    function allowedControllers(address) external view returns (bool);
    function allowedConverters(address) external view returns (bool);
    function allowedStrategies(address) external view returns (bool);
    function allowedVaults(address) external view returns (bool);
    function controllers(address) external view returns (address);
    function getHarvestFeeInfo() external view returns (address, address, uint256);
    function getToken(address) external view returns (address);
    function governance() external view returns (address);
    function halted() external view returns (bool);
    function harvester() external view returns (address);
    function insuranceFee() external view returns (uint256);
    function insurancePool() external view returns (address);
    function insurancePoolFee() external view returns (uint256);
    function pendingStrategist() external view returns (address);
    function removeVault(address) external;
    function stakingPool() external view returns (address);
    function stakingPoolShareFee() external view returns (uint256);
    function strategist() external view returns (address);
    function treasury() external view returns (address);
    function treasuryFee() external view returns (uint256);
    function withdrawalProtectionFee() external view returns (uint256);
    function yaxis() external view returns (address);
}

// File: contracts/v3/interfaces/IController.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "./IManager.sol";

interface IController {
    function balanceOf() external view returns (uint256);
    function converter(address _vault) external view returns (address);
    function earn(address _strategy, address _token, uint256 _amount) external;
    function investEnabled() external view returns (bool);
    function harvestStrategy(address _strategy, uint256[] calldata _estimates) external;
    function manager() external view returns (IManager);
    function strategies() external view returns (uint256);
    function withdraw(address _token, uint256 _amount) external;
    function withdrawAll(address _strategy, address _convert) external;
}

// File: contracts/v3/interfaces/IConverter.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "./IManager.sol";

interface IConverter {
    function manager() external view returns (IManager);
    function convert(
        address _input,
        address _output,
        uint256 _inputAmount,
        uint256 _estimatedOutput
    ) external returns (uint256 _outputAmount);
    function expected(
        address _input,
        address _output,
        uint256 _inputAmount
    ) external view returns (uint256 _outputAmount);
}

// File: contracts/v3/interfaces/IVault.sol



// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import "./IManager.sol";

interface IVault {
    function available() external view returns (uint256);
    function balance() external view returns (uint256);
    function deposit(uint256 _amount) external returns (uint256);
    function earn(address _strategy) external;
    function gauge() external returns (address);
    function getLPToken() external view returns (address);
    function getPricePerFullShare() external view returns (uint256);
    function getToken() external view returns (address);
    function manager() external view returns (IManager);
    function withdraw(uint256 _amount) external;
    function withdrawAll() external;
    function withdrawFee(uint256 _amount) external view returns (uint256);
}

// File: contracts/v3/interfaces/IVaultToken.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.2;

interface IVaultToken {
    function mint(address,uint256) external;
    function burn(address,uint256) external;
}

// File: contracts/v3/interfaces/ExtendedIERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.6.2;

interface ExtendedIERC20 {
    function decimals() external view returns (uint8);
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}