Contract Source Code:

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

pragma solidity ^0.8.0;

import "./IAccessControlUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "../utils/StringsUpgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms. This is a lightweight version that doesn't allow enumerating role
 * members except through off-chain means by accessing the contract event logs. Some
 * applications may benefit from on-chain enumerability, for those cases see
 * {AccessControlEnumerable}.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```solidity
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```solidity
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
 * to enforce additional security measures for this role.
 */
abstract contract AccessControlUpgradeable is Initializable, ContextUpgradeable, IAccessControlUpgradeable, ERC165Upgradeable {
    function __AccessControl_init() internal onlyInitializing {
    }

    function __AccessControl_init_unchained() internal onlyInitializing {
    }
    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role);
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IAccessControlUpgradeable).interfaceId || super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `_msgSender()` is missing `role`.
     * Overriding this function changes the behavior of the {onlyRole} modifier.
     *
     * Format of the revert message is described in {_checkRole}.
     *
     * _Available since v4.6._
     */
    function _checkRole(bytes32 role) internal view virtual {
        _checkRole(role, _msgSender());
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(account),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleGranted} event.
     */
    function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     *
     * May emit a {RoleRevoked} event.
     */
    function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     *
     * May emit a {RoleRevoked} event.
     */
    function renounceRole(bytes32 role, address account) public virtual override {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * May emit a {RoleGranted} event.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleGranted} event.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     *
     * May emit a {RoleRevoked} event.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)

pragma solidity ^0.8.0;

/**
 * @dev External interface of AccessControl declared to support ERC165 detection.
 */
interface IAccessControlUpgradeable {
    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {AccessControl-_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) external view returns (bool);

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {AccessControl-_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) external view returns (bytes32);

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) external;

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) external;
}

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

pragma solidity ^0.8.2;

import "../../utils/AddressUpgradeable.sol";

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since proxied contracts do not make use of a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
 * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
 * case an upgrade adds a module that needs to be initialized.
 *
 * For example:
 *
 * [.hljs-theme-light.nopadding]
 * ```solidity
 * contract MyToken is ERC20Upgradeable {
 *     function initialize() initializer public {
 *         __ERC20_init("MyToken", "MTK");
 *     }
 * }
 *
 * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
 *     function initializeV2() reinitializer(2) public {
 *         __ERC20Permit_init("MyToken");
 *     }
 * }
 * ```
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 *
 * [CAUTION]
 * ====
 * Avoid leaving a contract uninitialized.
 *
 * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
 * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
 * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
 *
 * [.hljs-theme-light.nopadding]
 * ```
 * /// @custom:oz-upgrades-unsafe-allow constructor
 * constructor() {
 *     _disableInitializers();
 * }
 * ```
 * ====
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     * @custom:oz-retyped-from bool
     */
    uint8 private _initialized;

    /**
     * @dev Indicates that the contract is in the process of being initialized.
     */
    bool private _initializing;

    /**
     * @dev Triggered when the contract has been initialized or reinitialized.
     */
    event Initialized(uint8 version);

    /**
     * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
     * `onlyInitializing` functions can be used to initialize parent contracts.
     *
     * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
     * constructor.
     *
     * Emits an {Initialized} event.
     */
    modifier initializer() {
        bool isTopLevelCall = !_initializing;
        require(
            (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
            "Initializable: contract is already initialized"
        );
        _initialized = 1;
        if (isTopLevelCall) {
            _initializing = true;
        }
        _;
        if (isTopLevelCall) {
            _initializing = false;
            emit Initialized(1);
        }
    }

    /**
     * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
     * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
     * used to initialize parent contracts.
     *
     * A reinitializer may be used after the original initialization step. This is essential to configure modules that
     * are added through upgrades and that require initialization.
     *
     * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
     * cannot be nested. If one is invoked in the context of another, execution will revert.
     *
     * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
     * a contract, executing them in the right order is up to the developer or operator.
     *
     * WARNING: setting the version to 255 will prevent any future reinitialization.
     *
     * Emits an {Initialized} event.
     */
    modifier reinitializer(uint8 version) {
        require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
        _initialized = version;
        _initializing = true;
        _;
        _initializing = false;
        emit Initialized(version);
    }

    /**
     * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
     * {initializer} and {reinitializer} modifiers, directly or indirectly.
     */
    modifier onlyInitializing() {
        require(_initializing, "Initializable: contract is not initializing");
        _;
    }

    /**
     * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
     * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
     * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
     * through proxies.
     *
     * Emits an {Initialized} event the first time it is successfully executed.
     */
    function _disableInitializers() internal virtual {
        require(!_initializing, "Initializable: contract is initializing");
        if (_initialized != type(uint8).max) {
            _initialized = type(uint8).max;
            emit Initialized(type(uint8).max);
        }
    }

    /**
     * @dev Returns the highest version that has been initialized. See {reinitializer}.
     */
    function _getInitializedVersion() internal view returns (uint8) {
        return _initialized;
    }

    /**
     * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
     */
    function _isInitializing() internal view returns (bool) {
        return _initializing;
    }
}

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

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal onlyInitializing {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal onlyInitializing {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20MetadataUpgradeable is IERC20Upgradeable {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20PermitUpgradeable {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    /**
     * @dev Returns the current nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases ``owner``'s nonce by one. This
     * prevents a signature from being used multiple times.
     */
    function nonces(address owner) external view returns (uint256);

    /**
     * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view returns (bytes32);
}

// 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 IERC20Upgradeable {
    /**
     * @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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20Upgradeable.sol";
import "../extensions/IERC20PermitUpgradeable.sol";
import "../../../utils/AddressUpgradeable.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 SafeERC20Upgradeable {
    using AddressUpgradeable for address;

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20Upgradeable token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20Upgradeable 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(IERC20Upgradeable 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'
        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));
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
     * 0 before setting it to a non-zero value.
     */
    function forceApprove(IERC20Upgradeable token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
            _callOptionalReturn(token, approvalCall);
        }
    }

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20PermitUpgradeable token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @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(IERC20Upgradeable 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");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
     * @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).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20Upgradeable token, bytes memory data) private returns (bool) {
        // 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 cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

        (bool success, bytes memory returndata) = address(token).call(data);
        return
            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && AddressUpgradeable.isContract(address(token));
    }
}

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

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library AddressUpgradeable {
    /**
     * @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
     *
     * Furthermore, `isContract` will also return true if the target contract within
     * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
     * which only has an effect at the end of a transaction.
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 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://consensys.net/diligence/blog/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/v0.8.0/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");

        (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 functionCallWithValue(target, data, 0, "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");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, 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) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // 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
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

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

pragma solidity ^0.8.0;
import "../proxy/utils/Initializable.sol";

/**
 * @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 ContextUpgradeable is Initializable {
    function __Context_init() internal onlyInitializing {
    }

    function __Context_init_unchained() internal onlyInitializing {
    }
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

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

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165Upgradeable.sol";
import "../../proxy/utils/Initializable.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
    function __ERC165_init() internal onlyInitializing {
    }

    function __ERC165_init_unchained() internal onlyInitializing {
    }
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165Upgradeable).interfaceId;
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[50] private __gap;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165Upgradeable {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// 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 MathUpgradeable {
    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);
        }
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)

pragma solidity ^0.8.0;

/**
 * @dev Standard signed math utilities missing in the Solidity language.
 */
library SignedMathUpgradeable {
    /**
     * @dev Returns the largest of two signed numbers.
     */
    function max(int256 a, int256 b) internal pure returns (int256) {
        return a > b ? a : b;
    }

    /**
     * @dev Returns the smallest of two signed numbers.
     */
    function min(int256 a, int256 b) internal pure returns (int256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two signed numbers without overflow.
     * The result is rounded towards zero.
     */
    function average(int256 a, int256 b) internal pure returns (int256) {
        // Formula from the book "Hacker's Delight"
        int256 x = (a & b) + ((a ^ b) >> 1);
        return x + (int256(uint256(x) >> 255) & (a ^ b));
    }

    /**
     * @dev Returns the absolute unsigned value of a signed value.
     */
    function abs(int256 n) internal pure returns (uint256) {
        unchecked {
            // must be unchecked in order to support `n = type(int256).min`
            return uint256(n >= 0 ? n : -n);
        }
    }
}

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

pragma solidity ^0.8.0;

import "./math/MathUpgradeable.sol";
import "./math/SignedMathUpgradeable.sol";

/**
 * @dev String operations.
 */
library StringsUpgradeable {
    bytes16 private constant _SYMBOLS = "0123456789abcdef";
    uint8 private constant _ADDRESS_LENGTH = 20;

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        unchecked {
            uint256 length = MathUpgradeable.log10(value) + 1;
            string memory buffer = new string(length);
            uint256 ptr;
            /// @solidity memory-safe-assembly
            assembly {
                ptr := add(buffer, add(32, length))
            }
            while (true) {
                ptr--;
                /// @solidity memory-safe-assembly
                assembly {
                    mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
                }
                value /= 10;
                if (value == 0) break;
            }
            return buffer;
        }
    }

    /**
     * @dev Converts a `int256` to its ASCII `string` decimal representation.
     */
    function toString(int256 value) internal pure returns (string memory) {
        return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMathUpgradeable.abs(value))));
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        unchecked {
            return toHexString(value, MathUpgradeable.log256(value) + 1);
        }
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }

    /**
     * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
     */
    function toHexString(address addr) internal pure returns (string memory) {
        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
    }

    /**
     * @dev Returns true if the two strings are equal.
     */
    function equal(string memory a, string memory b) internal pure returns (bool) {
        return keccak256(bytes(a)) == keccak256(bytes(b));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

pragma solidity ^0.8.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```solidity
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
library EnumerableSetUpgradeable {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping(bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            if (lastIndex != toDeleteIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the last value to the index where the value to delete is
                set._values[toDeleteIndex] = lastValue;
                // Update the index for the moved value
                set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT

pragma solidity 0.8.17;

interface IChainlinkV3Aggregator {
    function decimals() external view returns (uint8);

    function latestRoundData()
        external
        view
        returns (
            uint80 roundId,
            int256 answer,
            uint256 startedAt,
            uint256 updatedAt,
            uint80 answeredInRound
        );
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol';

interface IStableCoin is IERC20Upgradeable {
    function mint(address _to, uint256 _value) external;

    function burn(uint256 _value) external;

    function burnFrom(address _from, uint256 _value) external;

    function pause() external;

    function unpause() external;
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

interface IStrategy {
    error ZeroAmount();
    error ZeroAddress();
    error InvalidAmount();
    error InsufficientAmount();
    error Unauthorized();

    function deposit(
        address _account,
        uint _amount
    ) external returns (uint share);

    function withdraw(
        address _account,
        uint _shareAmount
    ) external returns (uint withdrawn);

    function getUnderlyingAmount(address _account) external view returns (uint);

    function toAmount(uint share) external view returns (uint);

    function pendingRewards(
        address _account
    ) external view returns (address[] memory, uint256[] memory);

    function claimRewards(address _account) external;
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol';

import '../../utils/AccessControlUpgradeable.sol';
import '../../utils/RateLib.sol';
import '../../interfaces/IChainlinkV3Aggregator.sol';

abstract contract ERC20ValueProviderBTC is
    ReentrancyGuardUpgradeable,
    AccessControlUpgradeable
{
    using RateLib for RateLib.Rate;

    error InvalidAmount(uint256 amount);
    error ZeroAddress();
    error InvalidOracleResults();
    error OracleTimeout();

    event NewBaseCreditLimitRate(RateLib.Rate rate);
    event NewBaseLiquidationLimitRate(RateLib.Rate rate);

    /// @notice The token oracles aggregator
    IChainlinkV3Aggregator public aggregator;

    /// @notice The token address
    IERC20MetadataUpgradeable public token;

    RateLib.Rate public baseCreditLimitRate;
    RateLib.Rate public baseLiquidationLimitRate;

    uint256 public oracleTimeout = 1 days;

    /// @notice This function is only called once during deployment of the proxy contract. It's not called after upgrades.
    /// @param _aggregator The token oracles aggregator
    /// @param _token The token address
    /// @param _baseCreditLimitRate The base credit limit rate
    /// @param _baseLiquidationLimitRate The base liquidation limit rate
    function __initialize(
        IChainlinkV3Aggregator _aggregator,
        IERC20MetadataUpgradeable _token,
        RateLib.Rate calldata _baseCreditLimitRate,
        RateLib.Rate calldata _baseLiquidationLimitRate
    ) internal onlyInitializing {
        __AccessControl_init();
        __ReentrancyGuard_init();

        if (address(_aggregator) == address(0)) revert ZeroAddress();

        _validateRateBelowOne(_baseCreditLimitRate);
        _validateRateBelowOne(_baseLiquidationLimitRate);

        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);

        aggregator = _aggregator;
        token = _token;
        baseCreditLimitRate = _baseCreditLimitRate;
        baseLiquidationLimitRate = _baseLiquidationLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The credit limit rate
    function getCreditLimitRate(
        address _owner,
        uint256 _colAmount
    ) public view returns (RateLib.Rate memory) {
        return baseCreditLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The liquidation limit rate
    function getLiquidationLimitRate(
        address _owner,
        uint256 _colAmount
    ) public view returns (RateLib.Rate memory) {
        return baseLiquidationLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The credit limit for collateral amount
    function getCreditLimitBTC(
        address _owner,
        uint256 _colAmount
    ) external view returns (uint256) {
        RateLib.Rate memory _creditLimitRate = getCreditLimitRate(
            _owner,
            _colAmount
        );
        return _creditLimitRate.calculate(getPriceBTC(_colAmount));
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The liquidation limit for collateral amount
    function getLiquidationLimitBTC(
        address _owner,
        uint256 _colAmount
    ) external view returns (uint256) {
        RateLib.Rate memory _liquidationLimitRate = getLiquidationLimitRate(
            _owner,
            _colAmount
        );
        return _liquidationLimitRate.calculate(getPriceBTC(_colAmount));
    }

    /// @return The value for the collection, in BTC.
    function getPriceBTC(uint256 colAmount) public view returns (uint256) {
        uint256 price = getPriceBTC();
        return (price * colAmount) / (10 ** token.decimals());
    }

    /// @return The value for the collection, in BTC.
    function getPriceBTC() public view virtual returns (uint256) {
        (, int256 answer, , uint256 timestamp, ) = aggregator.latestRoundData();

        if (answer == 0 || timestamp == 0) revert InvalidOracleResults();
        if (block.timestamp - timestamp > oracleTimeout) revert OracleTimeout();

        uint8 decimals = aggregator.decimals();

        unchecked {
            //converts the answer to have 18 decimals
            return
                decimals > 18
                    ? uint256(answer) / 10 ** (decimals - 18)
                    : uint256(answer) * 10 ** (18 - decimals);
        }
    }

    function setBaseCreditLimitRate(
        RateLib.Rate memory _baseCreditLimitRate
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _validateRateBelowOne(_baseCreditLimitRate);

        baseCreditLimitRate = _baseCreditLimitRate;

        emit NewBaseCreditLimitRate(_baseCreditLimitRate);
    }

    function setBaseLiquidationLimitRate(
        RateLib.Rate memory _liquidationLimitRate
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _validateRateBelowOne(_liquidationLimitRate);

        baseLiquidationLimitRate = _liquidationLimitRate;

        emit NewBaseLiquidationLimitRate(_liquidationLimitRate);
    }

    function setOracleTimeout(
        uint256 _timeout
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        oracleTimeout = _timeout;
    }

    /// @dev Validates a rate. The denominator must be greater than zero and greater than or equal to the numerator.
    /// @param _rate The rate to validate
    function _validateRateBelowOne(RateLib.Rate memory _rate) internal pure {
        if (!_rate.isValid() || _rate.isAboveOne())
            revert RateLib.InvalidRate();
    }
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/utils/structs/EnumerableSetUpgradeable.sol';

import '../../interfaces/IStableCoin.sol';
import '../../utils/RateLib.sol';
import '../usd/ERC20Vault.sol';
import {ERC20ValueProviderBTC} from './ERC20ValueProviderBTC.sol';

/// @title ERC20 lending vault
/// @notice This contracts allows users to borrow ShezmuBTC using ERC20 tokens as collateral.
/// The price of the collateral token is fetched using a chainlink oracle
contract ERC20VaultBTC is ERC20Vault {
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    using RateLib for RateLib.Rate;

    /// @notice This function is only called once during deployment of the proxy contract. It's not called after upgrades.
    /// @param _stablecoin ShezUSD address
    /// @param _tokenContract The collateral token address
    /// @param _valueProvider The collateral token value provider
    /// @param _settings Initial settings used by the contract
    function initialize(
        IStableCoin _stablecoin,
        IERC20Upgradeable _tokenContract,
        IStrategy _strategy,
        address _valueProvider,
        VaultSettings calldata _settings
    ) external override initializer {
        __initialize(_stablecoin, _settings);
        tokenContract = _tokenContract;
        valueProvider = _valueProvider;
        strategy = _strategy;
    }

    /// @dev Returns the credit limit
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return creditLimitBTC The credit limit
    function _getCreditLimit(
        address _owner,
        uint256 _colAmount
    ) internal view override returns (uint256 creditLimitBTC) {
        uint _uAmount = _colAmount;
        if (address(strategy) != address(0)) {
            _uAmount = strategy.toAmount(_colAmount);
        }
        creditLimitBTC = ERC20ValueProviderBTC(valueProvider).getCreditLimitBTC(
                _owner,
                _uAmount
            );
    }

    /// @dev Returns the minimum amount of debt necessary to liquidate the position
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return liquidationLimitBTC The minimum amount of debt to liquidate the position
    function _getLiquidationLimit(
        address _owner,
        uint256 _colAmount
    ) internal view override returns (uint256 liquidationLimitBTC) {
        uint _uAmount = _colAmount;
        if (address(strategy) != address(0)) {
            _uAmount = strategy.toAmount(_colAmount);
        }
        liquidationLimitBTC = ERC20ValueProviderBTC(valueProvider)
            .getLiquidationLimitBTC(_owner, _uAmount);
    }
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/utils/structs/EnumerableSetUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol';

import '../../interfaces/IStableCoin.sol';
import '../../utils/RateLib.sol';

/// @title ERC20 / ERC1155 lending vault
/// @notice This contracts allows users to borrow ShezmuUSD using ERC20/ERC1155 tokens as collateral.
/// The price of the collateral token is fetched using a chainlink oracle
abstract contract AbstractAssetVault is
    AccessControlUpgradeable,
    ReentrancyGuardUpgradeable
{
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using SafeERC20Upgradeable for IStableCoin;
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    using RateLib for RateLib.Rate;

    error InvalidAmount(uint256 amount);
    error InvalidPosition(address owner);
    error DebtCapReached();
    error NoDebt();
    error InsufficientCollateral();
    error UnknownAction(uint8 action);
    error InvalidLength();
    error MinBorrowAmount();

    event CollateralAdded(address indexed owner, uint256 colAmount);
    event Borrowed(address indexed owner, uint256 amount);
    event Repaid(address indexed owner, uint256 amount);
    event CollateralRemoved(address indexed owner, uint256 colAmount);
    event Liquidated(
        address indexed liquidator,
        address indexed owner,
        uint256 colAmount
    );

    event Accrual(uint256 additionalInterest);
    event FeeCollected(uint256 collectedAmount);

    struct Position {
        uint256 collateral;
        uint256 debtPrincipal;
        uint256 debtPortion;
    }

    struct VaultSettings {
        RateLib.Rate debtInterestApr;
        RateLib.Rate organizationFeeRate;
        uint256 borrowAmountCap;
        uint256 minBorrowAmount;
    }

    bytes32 internal constant DAO_ROLE = keccak256('DAO_ROLE');
    bytes32 internal constant LIQUIDATOR_ROLE = keccak256('LIQUIDATOR_ROLE');
    bytes32 internal constant SETTER_ROLE = keccak256('SETTER_ROLE');
    bytes32 internal constant LEVERAGE_ROLE = keccak256('LEVERAGE_ROLE');

    //accrue required
    uint8 internal constant ACTION_ADD_COLLATERAL = 0;
    uint8 internal constant ACTION_REMOVE_COLLATERAL = 1;
    uint8 internal constant ACTION_BORROW = 2;
    uint8 internal constant ACTION_REPAY = 3;
    uint8 internal constant ACTION_LIQUIDATE = 4;

    IStableCoin public stablecoin;

    /// @notice Total outstanding debt
    uint256 public totalDebtAmount;
    /// @dev Last time debt was accrued. See {accrue} for more info
    uint256 internal totalDebtAccruedAt;
    uint256 public totalFeeCollected;
    uint256 internal totalDebtPortion;

    VaultSettings public settings;

    /// @dev Keeps track of all the users
    EnumerableSetUpgradeable.AddressSet internal userIndexes;

    mapping(address => Position) public positions;

    /// @notice This function is only called once during deployment of the proxy contract. It's not called after upgrades.
    /// @param _stablecoin ShezUSD address
    /// @param _settings Initial settings used by the contract
    function __initialize(
        IStableCoin _stablecoin,
        VaultSettings calldata _settings
    ) internal onlyInitializing {
        __AccessControl_init();
        __ReentrancyGuard_init();

        _setupRole(DAO_ROLE, msg.sender);
        _setRoleAdmin(LIQUIDATOR_ROLE, DAO_ROLE);
        _setRoleAdmin(SETTER_ROLE, DAO_ROLE);
        _setRoleAdmin(LEVERAGE_ROLE, DAO_ROLE);
        _setRoleAdmin(DAO_ROLE, DAO_ROLE);

        if (
            !_settings.debtInterestApr.isValid() ||
            !_settings.debtInterestApr.isBelowOne()
        ) revert RateLib.InvalidRate();

        if (
            !_settings.organizationFeeRate.isValid() ||
            !_settings.organizationFeeRate.isBelowOne()
        ) revert RateLib.InvalidRate();

        stablecoin = _stablecoin;
        settings = _settings;
    }

    /// @notice Returns the number of open positions
    /// @return The number of open positions
    function totalUsersLength() external view returns (uint256) {
        return userIndexes.length();
    }

    /// @notice Returns all open position owners
    /// @return The open position owners
    function totalUsers() external view returns (address[] memory) {
        return userIndexes.values();
    }

    function getCollateral(address _owner) external view returns (uint256) {
        return positions[_owner].collateral;
    }

    /// @param _owner The position owner
    /// @return The ShezUSD credit limit of owner
    function getCreditLimit(address _owner) external view returns (uint256) {
        return _getCreditLimit(_owner, positions[_owner].collateral);
    }

    /// @param _owner The position owner
    /// @return The ShezUSD liquidation limit of owner
    function getLiquidationLimit(address _owner) public view returns (uint256) {
        return _getLiquidationLimit(_owner, positions[_owner].collateral);
    }

    /// @param _owner The position owner
    /// @return Whether the position is liquidatable or not
    function isLiquidatable(address _owner) external view returns (bool) {
        return
            positions[_owner].debtPrincipal + getDebtInterest(_owner) >=
            getLiquidationLimit(_owner);
    }

    /// @param _owner The position owner
    /// @return The ShezUSD debt interest accumulated
    function getDebtInterest(address _owner) public view returns (uint256) {
        Position storage position = positions[_owner];
        uint256 principal = position.debtPrincipal;
        uint256 debt = _calculateDebt(
            totalDebtAmount + calculateAdditionalInterest(),
            position.debtPortion,
            totalDebtPortion
        );

        //_calculateDebt is prone to rounding errors that may cause
        //the calculated debt amount to be 1 or 2 units less than
        //the debt principal if no time has elapsed in between the first borrow
        //and the _calculateDebt call.
        if (principal > debt) debt = principal;

        unchecked {
            return debt - principal;
        }
    }

    /// @dev Calculates the additional global interest since last time the contract's state was updated by calling {accrue}
    /// @return The additional interest value
    function calculateAdditionalInterest() public view returns (uint256) {
        // Number of seconds since {accrue} was called
        uint256 elapsedTime = block.timestamp - totalDebtAccruedAt;
        if (elapsedTime == 0) {
            return 0;
        }

        uint256 totalDebt = totalDebtAmount;
        if (totalDebt == 0) {
            return 0;
        }

        // Accrue interest
        return
            (elapsedTime * totalDebt * settings.debtInterestApr.numerator) /
            settings.debtInterestApr.denominator /
            365.25 days;
    }

    /// @dev The {accrue} function updates the contract's state by calculating
    /// the additional interest accrued since the last state update
    function accrue() public {
        uint256 additionalInterest = calculateAdditionalInterest();

        totalDebtAccruedAt = block.timestamp;

        totalDebtAmount += additionalInterest;
        totalFeeCollected += additionalInterest;

        emit Accrual(additionalInterest);
    }

    /// @notice Allows to execute multiple actions in a single transaction.
    /// @param _actions The actions to execute.
    /// @param _data The abi encoded parameters for the actions to execute.
    function doActions(
        uint8[] calldata _actions,
        bytes[] calldata _data
    ) external nonReentrant {
        _doActionsFor(msg.sender, _actions, _data);
    }

    /// @notice Allows a user to add collateral
    /// @param _colAmount The collateral amount
    function addCollateral(uint256 _colAmount) external nonReentrant {
        accrue();
        _addCollateral(msg.sender, msg.sender, _colAmount);
    }

    /// @notice Allows a user to add collateral on behalf of user
    /// @param _colAmount The collateral amount
    /// @param _onBehalfOf The onBeHalfOf user
    function addCollateralFor(
        uint _colAmount,
        address _onBehalfOf
    ) external nonReentrant onlyRole(LEVERAGE_ROLE) {
        accrue();
        _addCollateral(msg.sender, _onBehalfOf, _colAmount);
    }

    /// @notice Allows users to borrow ShezUSD
    /// @dev emits a {Borrowed} event
    /// @param _amount The amount of ShezUSD to be borrowed. Note that the user will receive less than the amount requested,
    function borrow(uint256 _amount) external nonReentrant {
        accrue();
        _borrow(msg.sender, msg.sender, _amount);
    }

    /// @notice Allows users to borrow ShezUSD
    /// @dev emits a {Borrowed} event
    /// @param _amount The amount of ShezUSD to be borrowed. Note that the user will receive less than the amount requested,
    function borrowFor(
        uint256 _amount,
        address _onBehalfOf
    ) external nonReentrant onlyRole(LEVERAGE_ROLE) {
        accrue();
        _borrow(msg.sender, _onBehalfOf, _amount);
    }

    /// @notice Allows users to repay a portion/all of their debt. Note that since interest increases every second,
    /// a user wanting to repay all of their debt should repay for an amount greater than their current debt to account for the
    /// additional interest while the repay transaction is pending, the contract will only take what's necessary to repay all the debt
    /// @dev Emits a {Repaid} event
    /// @param _amount The amount of debt to repay. If greater than the position's outstanding debt, only the amount necessary to repay all the debt will be taken
    function repay(uint256 _amount) external nonReentrant {
        accrue();
        _repay(msg.sender, _amount);
    }

    /// @notice Allows a user to remove collateral
    /// @dev Emits a {PositionClosed} event
    /// @param _colAmount The collateral amount
    function removeCollateral(uint256 _colAmount) external nonReentrant {
        accrue();
        _removeCollateral(msg.sender, _colAmount);
    }

    /// @notice Allows members of the `LIQUIDATOR_ROLE` to liquidate a position. Positions can only be liquidated
    /// once their debt amount exceeds the minimum liquidation debt to collateral value rate.
    /// In order to liquidate a position, the liquidator needs to repay the user's outstanding debt.
    /// @dev Emits a {Liquidated} event
    /// @param _owner The position owner
    /// @param _recipient The address to send collaterals to
    function liquidate(
        address _owner,
        address _recipient
    ) external nonReentrant {
        accrue();
        _liquidate(msg.sender, _owner, _recipient);
    }

    /// @notice Allows the DAO to collect interest and fees before they are repaid
    function collect() external nonReentrant onlyRole(DAO_ROLE) {
        accrue();

        uint256 _totalFeeCollected = totalFeeCollected;

        stablecoin.mint(msg.sender, _totalFeeCollected);
        totalFeeCollected = 0;

        emit FeeCollected(_totalFeeCollected);
    }

    /// @notice Allows the DAO to withdraw _amount of an ERC20
    function rescueToken(
        IERC20Upgradeable _token,
        uint256 _amount
    ) external nonReentrant onlyRole(DAO_ROLE) {
        _token.safeTransfer(msg.sender, _amount);
    }

    function setRoleAdmin(
        bytes32 role,
        bytes32 adminRole
    ) external nonReentrant onlyRole(DAO_ROLE) {
        _setRoleAdmin(role, adminRole);
    }

    function updateStablecoin(
        IStableCoin _stablecoin
    ) external onlyRole(DAO_ROLE) {
        stablecoin = _stablecoin;
    }

    /// @notice Allows the setter contract to change fields in the `VaultSettings` struct.
    /// @dev Validation and single field setting is handled by an external contract with the
    /// `SETTER_ROLE`. This was done to reduce the contract's size.
    function setSettings(
        VaultSettings calldata _settings
    ) external onlyRole(SETTER_ROLE) {
        accrue();

        if (
            !_settings.debtInterestApr.isValid() ||
            !_settings.debtInterestApr.isBelowOne()
        ) revert RateLib.InvalidRate();

        if (
            !_settings.organizationFeeRate.isValid() ||
            !_settings.organizationFeeRate.isBelowOne()
        ) revert RateLib.InvalidRate();

        settings = _settings;
    }

    /// @dev See {doActions}
    function _doActionsFor(
        address _account,
        uint8[] calldata _actions,
        bytes[] calldata _data
    ) internal {
        if (_actions.length != _data.length) revert InvalidLength();
        bool accrueCalled;
        for (uint256 i; i < _actions.length; ++i) {
            uint8 action = _actions[i];
            if (!accrueCalled && action < 100) {
                accrue();
                accrueCalled = true;
            }

            if (action == ACTION_ADD_COLLATERAL) {
                uint256 colAmount = abi.decode(_data[i], (uint256));
                _addCollateral(_account, _account, colAmount);
            } else if (action == ACTION_BORROW) {
                uint256 amount = abi.decode(_data[i], (uint256));
                _borrow(_account, _account, amount);
            } else if (action == ACTION_REPAY) {
                uint256 amount = abi.decode(_data[i], (uint256));
                _repay(_account, amount);
            } else if (action == ACTION_REMOVE_COLLATERAL) {
                uint256 colAmount = abi.decode(_data[i], (uint256));
                _removeCollateral(_account, colAmount);
            } else if (action == ACTION_LIQUIDATE) {
                (address owner, address recipient) = abi.decode(
                    _data[i],
                    (address, address)
                );
                _liquidate(_account, owner, recipient);
            } else {
                revert UnknownAction(action);
            }
        }
    }

    /// @dev See {addCollateral}
    function _addCollateral(
        address _account,
        address _onBehalfOf,
        uint256 _colAmount
    ) internal virtual {}

    /// @dev See {borrow}
    function _borrow(
        address _account,
        address _onBehalfOf,
        uint256 _amount
    ) internal {
        if (_amount < settings.minBorrowAmount) {
            revert MinBorrowAmount();
        }

        uint256 _totalDebtAmount = totalDebtAmount;
        if (_totalDebtAmount + _amount > settings.borrowAmountCap)
            revert DebtCapReached();

        Position storage position = positions[_onBehalfOf];
        uint256 _creditLimit = _getCreditLimit(
            _onBehalfOf,
            position.collateral
        );
        uint256 _debtAmount = _getDebtAmount(_onBehalfOf);
        if (_debtAmount + _amount > _creditLimit) revert InvalidAmount(_amount);

        //calculate the borrow fee
        uint256 _organizationFee = (_amount *
            settings.organizationFeeRate.numerator) /
            settings.organizationFeeRate.denominator;

        uint256 _feeAmount = _organizationFee;
        totalFeeCollected += _feeAmount;

        // update debt portion
        {
            uint256 _totalDebtPortion = totalDebtPortion;
            uint256 _plusPortion = _calculatePortion(
                _totalDebtPortion,
                _amount,
                _totalDebtAmount
            );

            totalDebtPortion = _totalDebtPortion + _plusPortion;
            position.debtPortion += _plusPortion;
            position.debtPrincipal += _amount;
            totalDebtAmount = _totalDebtAmount + _amount;
        }

        //subtract the fee from the amount borrowed
        stablecoin.mint(_account, _amount - _feeAmount);

        emit Borrowed(_onBehalfOf, _amount);
    }

    /// @dev See {repay}
    function _repay(address _account, uint256 _amount) internal {
        if (_amount == 0) revert InvalidAmount(_amount);

        Position storage position = positions[_account];

        uint256 _debtAmount = _getDebtAmount(_account);
        if (_debtAmount == 0) revert NoDebt();

        uint256 _debtPrincipal = position.debtPrincipal;
        uint256 _debtInterest = _debtAmount - _debtPrincipal;

        _amount = _amount > _debtAmount ? _debtAmount : _amount;

        // burn all payment, the interest is sent to the DAO using the {collect} function
        stablecoin.burnFrom(_account, _amount);

        uint256 _paidPrincipal;

        unchecked {
            _paidPrincipal = _amount > _debtInterest
                ? _amount - _debtInterest
                : 0;
        }

        uint256 _totalDebtPortion = totalDebtPortion;
        uint256 _totalDebtAmount = totalDebtAmount;
        uint256 _debtPortion = position.debtPortion;
        uint256 _minusPortion = _paidPrincipal == _debtPrincipal
            ? _debtPortion
            : _calculatePortion(_totalDebtPortion, _amount, _totalDebtAmount);

        totalDebtPortion = _totalDebtPortion - _minusPortion;
        position.debtPortion = _debtPortion - _minusPortion;
        position.debtPrincipal = _debtPrincipal - _paidPrincipal;
        totalDebtAmount = _totalDebtAmount - _amount;

        if (
            position.debtPrincipal > 0 &&
            position.debtPrincipal < settings.minBorrowAmount
        ) {
            revert MinBorrowAmount();
        }

        emit Repaid(_account, _amount);
    }

    /// @dev See {removeCollateral}
    function _removeCollateral(
        address _account,
        uint256 _colAmount
    ) internal virtual {}

    /// @dev See {liquidate}
    function _liquidate(
        address _account,
        address _owner,
        address _recipient
    ) internal virtual {}

    /// @dev Returns the credit limit
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return The credit limit
    function _getCreditLimit(
        address _owner,
        uint256 _colAmount
    ) internal view virtual returns (uint256) {}

    /// @dev Returns the minimum amount of debt necessary to liquidate the position
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return The minimum amount of debt to liquidate the position
    function _getLiquidationLimit(
        address _owner,
        uint256 _colAmount
    ) internal view virtual returns (uint256) {}

    /// @dev Calculates current outstanding debt of a user
    /// @param _owner The position owner
    /// @return The outstanding debt value
    function _getDebtAmount(address _owner) internal view returns (uint256) {
        uint256 calculatedDebt = _calculateDebt(
            totalDebtAmount,
            positions[_owner].debtPortion,
            totalDebtPortion
        );

        uint256 principal = positions[_owner].debtPrincipal;

        //_calculateDebt is prone to rounding errors that may cause
        //the calculated debt amount to be 1 or 2 units less than
        //the debt principal when the accrue() function isn't called
        //in between the first borrow and the _calculateDebt call.
        return principal > calculatedDebt ? principal : calculatedDebt;
    }

    /// @dev Calculates the total debt of a position given the global debt, the user's portion of the debt and the total user portions
    /// @param total The global outstanding debt
    /// @param userPortion The user's portion of debt
    /// @param totalPortion The total user portions of debt
    /// @return The outstanding debt of the position
    function _calculateDebt(
        uint256 total,
        uint256 userPortion,
        uint256 totalPortion
    ) internal pure returns (uint256) {
        return totalPortion == 0 ? 0 : (total * userPortion) / totalPortion;
    }

    /// @dev Calculates the debt portion of a position given the global debt portion, the debt amount and the global debt amount
    /// @param _total The total user portions of debt
    /// @param _userDebt The user's debt
    /// @param _totalDebt The global outstanding debt
    /// @return _userDebt converted into a debt portion
    function _calculatePortion(
        uint256 _total,
        uint256 _userDebt,
        uint256 _totalDebt
    ) internal pure returns (uint256) {
        return _total == 0 ? _userDebt : (_total * _userDebt) / _totalDebt;
    }
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/token/ERC20/extensions/IERC20MetadataUpgradeable.sol';

import '../../utils/AccessControlUpgradeable.sol';
import '../../utils/RateLib.sol';
import '../../interfaces/IChainlinkV3Aggregator.sol';

abstract contract ERC20ValueProvider is
    ReentrancyGuardUpgradeable,
    AccessControlUpgradeable
{
    using RateLib for RateLib.Rate;

    error InvalidAmount(uint256 amount);
    error ZeroAddress();
    error InvalidOracleResults();
    error OracleTimeout();

    event NewBaseCreditLimitRate(RateLib.Rate rate);
    event NewBaseLiquidationLimitRate(RateLib.Rate rate);

    /// @notice The token oracles aggregator
    IChainlinkV3Aggregator public aggregator;

    /// @notice The token address
    IERC20MetadataUpgradeable public token;

    RateLib.Rate public baseCreditLimitRate;
    RateLib.Rate public baseLiquidationLimitRate;

    uint256 public oracleTimeout = 1 days;

    /// @notice This function is only called once during deployment of the proxy contract. It's not called after upgrades.
    /// @param _aggregator The token oracles aggregator
    /// @param _token The token address
    /// @param _baseCreditLimitRate The base credit limit rate
    /// @param _baseLiquidationLimitRate The base liquidation limit rate
    function __initialize(
        IChainlinkV3Aggregator _aggregator,
        IERC20MetadataUpgradeable _token,
        RateLib.Rate calldata _baseCreditLimitRate,
        RateLib.Rate calldata _baseLiquidationLimitRate
    ) internal onlyInitializing {
        __AccessControl_init();
        __ReentrancyGuard_init();

        if (address(_aggregator) == address(0)) revert ZeroAddress();

        _validateRateBelowOne(_baseCreditLimitRate);
        _validateRateBelowOne(_baseLiquidationLimitRate);

        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);

        aggregator = _aggregator;
        token = _token;
        baseCreditLimitRate = _baseCreditLimitRate;
        baseLiquidationLimitRate = _baseLiquidationLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The credit limit rate
    function getCreditLimitRate(
        address _owner,
        uint256 _colAmount
    ) public view returns (RateLib.Rate memory) {
        return baseCreditLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The liquidation limit rate
    function getLiquidationLimitRate(
        address _owner,
        uint256 _colAmount
    ) public view returns (RateLib.Rate memory) {
        return baseLiquidationLimitRate;
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The credit limit for collateral amount
    function getCreditLimitUSD(
        address _owner,
        uint256 _colAmount
    ) external view returns (uint256) {
        RateLib.Rate memory _creditLimitRate = getCreditLimitRate(
            _owner,
            _colAmount
        );
        return _creditLimitRate.calculate(getPriceUSD(_colAmount));
    }

    /// @param _owner The owner address
    /// @param _colAmount The collateral amount
    /// @return The liquidation limit for collateral amount
    function getLiquidationLimitUSD(
        address _owner,
        uint256 _colAmount
    ) external view returns (uint256) {
        RateLib.Rate memory _liquidationLimitRate = getLiquidationLimitRate(
            _owner,
            _colAmount
        );
        return _liquidationLimitRate.calculate(getPriceUSD(_colAmount));
    }

    /// @return The value for the collection, in USD.
    function getPriceUSD(uint256 colAmount) public view returns (uint256) {
        uint256 price = getPriceUSD();
        return (price * colAmount) / (10 ** token.decimals());
    }

    /// @return The value for the collection, in USD.
    function getPriceUSD() public view virtual returns (uint256) {
        (, int256 answer, , uint256 timestamp, ) = aggregator.latestRoundData();

        if (answer == 0 || timestamp == 0) revert InvalidOracleResults();
        if (block.timestamp - timestamp > oracleTimeout) revert OracleTimeout();

        uint8 decimals = aggregator.decimals();

        unchecked {
            //converts the answer to have 18 decimals
            return
                decimals > 18
                    ? uint256(answer) / 10 ** (decimals - 18)
                    : uint256(answer) * 10 ** (18 - decimals);
        }
    }

    function setBaseCreditLimitRate(
        RateLib.Rate memory _baseCreditLimitRate
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _validateRateBelowOne(_baseCreditLimitRate);

        baseCreditLimitRate = _baseCreditLimitRate;

        emit NewBaseCreditLimitRate(_baseCreditLimitRate);
    }

    function setBaseLiquidationLimitRate(
        RateLib.Rate memory _liquidationLimitRate
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        _validateRateBelowOne(_liquidationLimitRate);

        baseLiquidationLimitRate = _liquidationLimitRate;

        emit NewBaseLiquidationLimitRate(_liquidationLimitRate);
    }

    function setOracleTimeout(
        uint256 _timeout
    ) external onlyRole(DEFAULT_ADMIN_ROLE) {
        oracleTimeout = _timeout;
    }

    /// @dev Validates a rate. The denominator must be greater than zero and greater than or equal to the numerator.
    /// @param _rate The rate to validate
    function _validateRateBelowOne(RateLib.Rate memory _rate) internal pure {
        if (!_rate.isValid() || _rate.isAboveOne())
            revert RateLib.InvalidRate();
    }
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import '@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/utils/structs/EnumerableSetUpgradeable.sol';
import '@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol';

import '../../interfaces/IStableCoin.sol';
import '../../interfaces/IStrategy.sol';
import '../../utils/RateLib.sol';
import {ERC20ValueProvider} from './ERC20ValueProvider.sol';
import {AbstractAssetVault} from './AbstractAssetVault.sol';

/// @title ERC20 lending vault
/// @notice This contracts allows users to borrow ShezmuUSD using ERC20 tokens as collateral.
/// The price of the collateral token is fetched using a chainlink oracle
contract ERC20Vault is AbstractAssetVault {
    using SafeERC20Upgradeable for IERC20Upgradeable;
    using SafeERC20Upgradeable for IStableCoin;
    using EnumerableSetUpgradeable for EnumerableSetUpgradeable.AddressSet;
    using RateLib for RateLib.Rate;
    /// @notice The Shezmu trait boost locker contract
    address public valueProvider;

    IERC20Upgradeable public tokenContract;

    IStrategy public strategy;

    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() {
        _disableInitializers();
    }

    /// @notice This function is only called once during deployment of the proxy contract. It's not called after upgrades.
    /// @param _stablecoin ShezUSD address
    /// @param _tokenContract The collateral token address
    /// @param _valueProvider The collateral token value provider
    /// @param _settings Initial settings used by the contract
    function initialize(
        IStableCoin _stablecoin,
        IERC20Upgradeable _tokenContract,
        IStrategy _strategy,
        address _valueProvider,
        VaultSettings calldata _settings
    ) external virtual initializer {
        __initialize(_stablecoin, _settings);
        tokenContract = _tokenContract;
        valueProvider = _valueProvider;
        strategy = _strategy;
    }

    function setValueProvider(
        address _valueProvider
    ) external onlyRole(SETTER_ROLE) {
        valueProvider = _valueProvider;
    }

    /// @dev See {addCollateral}
    function _addCollateral(
        address _account,
        address _onBehalfOf,
        uint256 _colAmount
    ) internal override {
        if (_colAmount == 0) revert InvalidAmount(_colAmount);

        tokenContract.safeTransferFrom(_account, address(this), _colAmount);
        uint share = _colAmount;
        if (address(strategy) != address(0)) {
            tokenContract.safeApprove(address(strategy), _colAmount);
            share = strategy.deposit(_onBehalfOf, _colAmount);
        }

        Position storage position = positions[_onBehalfOf];

        if (!userIndexes.contains(_onBehalfOf)) {
            userIndexes.add(_onBehalfOf);
        }
        position.collateral += share;

        emit CollateralAdded(_onBehalfOf, _colAmount);
    }

    /// @dev See {removeCollateral}
    function _removeCollateral(
        address _account,
        uint256 _colShare
    ) internal override {
        Position storage position = positions[_account];

        uint256 _debtAmount = _getDebtAmount(_account);
        uint256 _creditLimit = _getCreditLimit(
            _account,
            position.collateral - _colShare
        );

        if (_debtAmount > _creditLimit) revert InsufficientCollateral();

        uint withdrawn = _colShare;
        if (address(strategy) != address(0)) {
            withdrawn = strategy.withdraw(_account, _colShare);
        }
        position.collateral -= _colShare;

        if (position.collateral == 0) {
            delete positions[_account];
            userIndexes.remove(_account);
        }

        tokenContract.safeTransfer(_account, withdrawn);

        emit CollateralRemoved(_account, withdrawn);
    }

    /// @dev See {liquidate}
    function _liquidate(
        address _account,
        address _owner,
        address _recipient
    ) internal override {
        _checkRole(LIQUIDATOR_ROLE, _account);

        Position storage position = positions[_owner];
        uint256 colAmount = position.collateral;

        uint256 debtAmount = _getDebtAmount(_owner);
        if (debtAmount < _getLiquidationLimit(_owner, position.collateral))
            revert InvalidPosition(_owner);

        // burn all payment
        stablecoin.burnFrom(_account, debtAmount);

        // update debt portion
        totalDebtPortion -= position.debtPortion;
        totalDebtAmount -= debtAmount;

        // transfer collateral to liquidator
        delete positions[_owner];
        userIndexes.remove(_owner);
        tokenContract.safeTransfer(_recipient, colAmount);

        emit Liquidated(_account, _owner, colAmount);
    }

    /// @dev Returns the credit limit
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return creditLimitUSD The credit limit
    function _getCreditLimit(
        address _owner,
        uint256 _colAmount
    ) internal view virtual override returns (uint256 creditLimitUSD) {
        uint _uAmount = _colAmount;
        if (address(strategy) != address(0)) {
            _uAmount = strategy.toAmount(_colAmount);
        }
        creditLimitUSD = ERC20ValueProvider(valueProvider).getCreditLimitUSD(
            _owner,
            _uAmount
        );
    }

    /// @dev Returns the minimum amount of debt necessary to liquidate the position
    /// @param _owner The position owner
    /// @param _colAmount The collateral amount
    /// @return liquidationLimitUSD The minimum amount of debt to liquidate the position
    function _getLiquidationLimit(
        address _owner,
        uint256 _colAmount
    ) internal view virtual override returns (uint256 liquidationLimitUSD) {
        uint _uAmount = _colAmount;
        if (address(strategy) != address(0)) {
            _uAmount = strategy.toAmount(_colAmount);
        }
        liquidationLimitUSD = ERC20ValueProvider(valueProvider)
            .getLiquidationLimitUSD(_owner, _uAmount);
    }
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

import "@openzeppelin/contracts-upgradeable/access/IAccessControlUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
import "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";

//copy paste of openzeppelin's {AccessControlUpgradeable} contract but instead of extending
//{ERC165Upgradeable} it extends {ERC165} to have the storage layout match {OwnableUpgradeable}'s
//and allow replacing it.
abstract contract AccessControlUpgradeable is
    Initializable,
    ContextUpgradeable,
    IAccessControlUpgradeable,
    ERC165
{
    function __AccessControl_init() internal onlyInitializing {}

    function __AccessControl_init_unchained() internal onlyInitializing {}

    struct RoleData {
        mapping(address => bool) members;
        bytes32 adminRole;
    }

    mapping(bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Modifier that checks that an account has a specific role. Reverts
     * with a standardized message including the required role.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     *
     * _Available since v4.1._
     */
    modifier onlyRole(bytes32 role) {
        _checkRole(role, _msgSender());
        _;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(
        bytes4 interfaceId
    ) public view virtual override returns (bool) {
        return
            interfaceId == type(IAccessControlUpgradeable).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(
        bytes32 role,
        address account
    ) public view virtual override returns (bool) {
        return _roles[role].members[account];
    }

    /**
     * @dev Revert with a standard message if `account` is missing `role`.
     *
     * The format of the revert reason is given by the following regular expression:
     *
     *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
     */
    function _checkRole(bytes32 role, address account) internal view virtual {
        if (!hasRole(role, account)) {
            revert(
                string(
                    abi.encodePacked(
                        "AccessControl: account ",
                        StringsUpgradeable.toHexString(uint160(account), 20),
                        " is missing role ",
                        StringsUpgradeable.toHexString(uint256(role), 32)
                    )
                )
            );
        }
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(
        bytes32 role
    ) public view virtual override returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(
        bytes32 role,
        address account
    ) public virtual override onlyRole(getRoleAdmin(role)) {
        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(
        bytes32 role,
        address account
    ) public virtual override onlyRole(getRoleAdmin(role)) {
        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been revoked `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(
        bytes32 role,
        address account
    ) public virtual override {
        require(
            account == _msgSender(),
            "AccessControl: can only renounce roles for self"
        );

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     *
     * NOTE: This function is deprecated in favor of {_grantRole}.
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        bytes32 previousAdminRole = getRoleAdmin(role);
        _roles[role].adminRole = adminRole;
        emit RoleAdminChanged(role, previousAdminRole, adminRole);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * Internal function without access restriction.
     */
    function _grantRole(bytes32 role, address account) internal virtual {
        if (!hasRole(role, account)) {
            _roles[role].members[account] = true;
            emit RoleGranted(role, account, _msgSender());
        }
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * Internal function without access restriction.
     */
    function _revokeRole(bytes32 role, address account) internal virtual {
        if (hasRole(role, account)) {
            _roles[role].members[account] = false;
            emit RoleRevoked(role, account, _msgSender());
        }
    }

    /**
     * @dev This empty reserved space is put in place to allow future versions to add new
     * variables without shifting down storage in the inheritance chain.
     * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
     */
    uint256[49] private __gap;
}

// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.17;

library RateLib {
    error InvalidRate();

    struct Rate {
        uint128 numerator;
        uint128 denominator;
    }

    function isValid(Rate memory _rate) internal pure returns (bool) {
        return _rate.denominator != 0;
    }

    function isZero(Rate memory _rate) internal pure returns (bool) {
        return _rate.numerator == 0;
    }

    function isAboveOne(Rate memory _rate) internal pure returns (bool) {
        return _rate.numerator > _rate.denominator;
    }

    function isBelowOne(Rate memory _rate) internal pure returns (bool) {
        return _rate.denominator > _rate.numerator;
    }

    function isOne(Rate memory _rate) internal pure returns (bool) {
        return _rate.numerator == _rate.denominator;
    }

    function greaterThan(
        Rate memory _r1,
        Rate memory _r2
    ) internal pure returns (bool) {
        return
            _r1.numerator * _r2.denominator > _r2.numerator * _r1.denominator;
    }

    function sum(
        Rate memory _r1,
        Rate memory _r2
    ) internal pure returns (Rate memory) {
        return
            Rate({
                numerator: _r1.numerator *
                    _r2.denominator +
                    _r1.denominator *
                    _r2.numerator,
                denominator: _r1.denominator * _r2.denominator
            });
    }

    function calculate(
        Rate memory _rate,
        uint256 _num
    ) internal pure returns (uint256) {
        return (_num * _rate.numerator) / _rate.denominator;
    }
}