// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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 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 `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, 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 `from` to `to` 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 from, address to, uint256 amount) external returns (bool);
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^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 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) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/utils/math/Math.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    enum Rounding {
        Down, // Toward negative infinity
        Up, // Toward infinity
        Zero // Toward zero
    }

    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a == 0 ? 0 : (a - 1) / b + 1;
    }

    /**
     * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
     * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
     * with further edits by Uniswap Labs also under MIT license.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
        unchecked {
            // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
            // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
            // variables such that product = prod1 * 2^256 + prod0.
            uint256 prod0; // Least significant 256 bits of the product
            uint256 prod1; // Most significant 256 bits of the product
            assembly {
                let mm := mulmod(x, y, not(0))
                prod0 := mul(x, y)
                prod1 := sub(sub(mm, prod0), lt(mm, prod0))
            }

            // Handle non-overflow cases, 256 by 256 division.
            if (prod1 == 0) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

            ///////////////////////////////////////////////
            // 512 by 256 division.
            ///////////////////////////////////////////////

            // Make division exact by subtracting the remainder from [prod1 prod0].
            uint256 remainder;
            assembly {
                // Compute remainder using mulmod.
                remainder := mulmod(x, y, denominator)

                // Subtract 256 bit number from 512 bit number.
                prod1 := sub(prod1, gt(remainder, prod0))
                prod0 := sub(prod0, remainder)
            }

            // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
            // See https://cs.stackexchange.com/q/138556/92363.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
            // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2^4.
            uint256 inverse = (3 * denominator) ^ 2;

            // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2^8
            inverse *= 2 - denominator * inverse; // inverse mod 2^16
            inverse *= 2 - denominator * inverse; // inverse mod 2^32
            inverse *= 2 - denominator * inverse; // inverse mod 2^64
            inverse *= 2 - denominator * inverse; // inverse mod 2^128
            inverse *= 2 - denominator * inverse; // inverse mod 2^256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
            // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}

// File: contracts/earn/FeeManager.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";
import "../interfaces/IFeeManager.sol";
import "../interfaces/IVault.sol";
import "../interfaces/IVaultFactory.sol";

contract FeeManager is IFeeManager, Ownable {

    /* ========== STATES ========== */

    address public override protocolFeeTo;
    address public override redemptionFeeTo;

    IVaultFactory public immutable factory;
    uint public maxProtocolFee;
    uint public minRedemptionFee;
    uint public maxRedemptionAdjustment;
    uint public override protocolRedemptionFeeShare;
    uint public maxRedemptionCap;
    uint public redemptionSupplyPerSec;
    uint public lastRedemptionTime;
    uint public redeemed;
    uint public constant PRECISION = 1e18;

    /* ========== CONSTRUCTOR ========== */

    constructor(IVaultFactory _factory, address _protocolFeeTo, address _redemptionFeeTo) {
        factory = _factory;
        protocolFeeTo = _protocolFeeTo;
        redemptionFeeTo = _redemptionFeeTo;
        maxProtocolFee = 40e16; // default to 40%
        minRedemptionFee = 5e15; // default to 0.5%
        maxRedemptionAdjustment = 15e15; // default to 1.5%
        protocolRedemptionFeeShare = 5e17; // default to 50%
        maxRedemptionCap = 100e18; // default to 100 ETH
        redemptionSupplyPerSec = 12e14; // default to 103 ETH restore per day
    }

    /* ========== VIEWS ========== */

    // Calculate protocol fee based on mint ratio
    function protocolFee(address _vault, uint _yield) public view override returns (uint) {
        return _yield * IVault(_vault).mintRatio() / PRECISION * maxProtocolFee / PRECISION;
    }

    // Calculate redemption fee based on mint ratio
    function redemptionFee(address _vault, uint _redeemAmount) public view override returns (uint) {
        return _redeemAmount * (minRedemptionFee + maxRedemptionAdjustment * (PRECISION - IVault(_vault).mintRatio()) / PRECISION) / PRECISION;
    }

    function redemptionSupplyRestored() public view returns (uint) {
        return (block.timestamp - lastRedemptionTime) * redemptionSupplyPerSec;
    }

    function availableRedemption() public view returns (uint) {
        uint restoredSupply = redemptionSupplyRestored();
        return Math.min(maxRedemptionCap, maxRedemptionCap + restoredSupply - redeemed);
    }

    /* ========== MUTATIVE FUNCTIONS ========== */

    function beforeRedeem(uint _amount) external override {
        require(availableRedemption() >= _amount, "!redeem");
    }

    function afterRedeem(uint _amount) external override {
        require(factory.isVault(msg.sender), "!vault");
        uint restoredSupply = redemptionSupplyRestored();
        if (restoredSupply >= redeemed) {
            redeemed = _amount;
        } else {
            redeemed = redeemed + _amount - restoredSupply;
        }
        lastRedemptionTime = block.timestamp;
    }

    /* ========== ADMIN FUNCTIONS ========== */

    function setMinRedemptionFee(uint _minRedemptionFee) external onlyOwner {
        require(_minRedemptionFee > 0 && _minRedemptionFee <= 2e16, "fee needs to be > 0 and <= 2%");
        minRedemptionFee = _minRedemptionFee;
        emit SetMinRedemptionFee(_minRedemptionFee);
    }

    function setMaxRedemptionAdjustment(uint _maxRedemptionAdjustment) external onlyOwner {
        require(_maxRedemptionAdjustment > 0 && _maxRedemptionAdjustment <= 3e16, "adjustment needs to be > 0 and <= 3%");
        maxRedemptionAdjustment = _maxRedemptionAdjustment;
        emit SetMaxRedemptionAdjustment(_maxRedemptionAdjustment);
    }

    function setProtocolRedemptionFeeShare(uint _protocolRedemptionFeeShare) external onlyOwner {
        protocolRedemptionFeeShare = _protocolRedemptionFeeShare;
        emit SetProtocolRedemptionFeeShare(_protocolRedemptionFeeShare);
    }

    function setRedemptionFeeTo(address _redemptionFeeTo) external onlyOwner {
        redemptionFeeTo = _redemptionFeeTo;
        emit SetRedemptionFeeTo(_redemptionFeeTo);
    }

    function setMaxProtocolFee(uint _maxProtocolFee) external onlyOwner {
        require(_maxProtocolFee > 0 && _maxProtocolFee <= 1e18, "fee needs to be > 0 and < 100%");
        maxProtocolFee = _maxProtocolFee;
        emit SetMaxProtocolFee(_maxProtocolFee);
    }

    function setProtocolFeeTo(address _protocolFeeTo) external onlyOwner {
        protocolFeeTo = _protocolFeeTo;
        emit SetProtocolFeeTo(_protocolFeeTo);
    }

    function setRedemptionParams(uint _maxRedemptionCap, uint _redemptionSupplyPerSec) external onlyOwner {
        maxRedemptionCap = _maxRedemptionCap;
        redemptionSupplyPerSec = _redemptionSupplyPerSec;
        // Reset related params
        redeemed = 0;
        lastRedemptionTime = block.timestamp;
        emit SetRedemptionParams(_maxRedemptionCap, _redemptionSupplyPerSec);
    }

    /* ========== EVENTS ========== */

    event SetMinRedemptionFee(uint minRedemptionFee);
    event SetMaxRedemptionAdjustment(uint maxRedemptionAdjustment);
    event SetProtocolRedemptionFeeShare(uint protocolRedemptionFeeShare);
    event SetRedemptionFeeTo(address indexed redemptionFeeTo);
    event SetMaxProtocolFee(uint maxProtocolFee);
    event SetProtocolFeeTo(address indexed protocolFeeTo);
    event SetRedemptionParams(uint maxRedemptionCap, uint redemptionSupplyPerSec);
}

// File: contracts/interfaces/IFeeManager.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import "./IMintableBurnableERC20.sol";

interface IFeeManager {
    function protocolFee(address, uint) external view returns (uint);
    function redemptionFee(address, uint) external view returns (uint);
    function protocolRedemptionFeeShare() external view returns (uint);
    function protocolFeeTo() external view returns (address);
    function redemptionFeeTo() external view returns (address);

    function beforeRedeem(uint) external;
    function afterRedeem(uint) external;
}

// File: contracts/interfaces/IMintableBurnableERC20.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

interface IMintableBurnableERC20 is IERC20 {
    function mint(address _to, uint256 _amount) external;
    function burn(uint256 _amount) external;
    function transferOwner(address _owner) external;
    function setMinter(address _minter, bool _status) external;
}

// File: contracts/interfaces/IVault.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import "./IVaultFactory.sol";

interface IVault {
    function initialize(address) external;

    function factory() external view returns (IVaultFactory);
    function owner() external view returns (address);
    function deposited() external view returns (uint);
    function minted() external view returns (uint);
    function availableBalance() external view returns (uint);
    function pendingYield() external view returns (uint);
    function mintRatio() external view returns (uint);
    
    function deposit(uint) external returns (uint);
    function withdraw(uint) external;
    function mint(uint) external;
    function burn(uint) external;
    function redeem(uint) external;
    function claim() external;
}

// File: contracts/interfaces/IVaultFactory.sol



// SPDX-License-Identifier: GPL-3.0

pragma solidity 0.8.17;

import "./IMintableBurnableERC20.sol";

interface IVaultFactory {
    function collateral() external view returns (IERC20);
    function token() external view returns (IMintableBurnableERC20);
    function feeManager() external view returns (address);

    function createVault(address) external returns (address);
    function getVault(address) external view returns (address);
    function allVaults(uint) external view returns (address);
    function isVault(address) external view returns (bool);
    function isVaultManager(address) external view returns (bool);
    function vaultsLength() external view returns (uint);
}