// 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 Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     *
     * 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 (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: GPL-3.0-or-later
pragma solidity ^0.8.0;

library ArrayLib {
    function sum(uint256[] memory input) internal pure returns (uint256) {
        uint256 value = 0;
        for (uint256 i = 0; i < input.length; ) {
            value += input[i];
            unchecked {
                i++;
            }
        }
        return value;
    }

    /// @notice return index of the element if found, else return uint256.max
    function find(address[] memory array, address element) internal pure returns (uint256 index) {
        uint256 length = array.length;
        for (uint256 i = 0; i < length; ) {
            if (array[i] == element) return i;
            unchecked {
                i++;
            }
        }
        return type(uint256).max;
    }

    function append(address[] memory inp, address element) internal pure returns (address[] memory out) {
        uint256 length = inp.length;
        out = new address[](length + 1);
        for (uint256 i = 0; i < length; ) {
            out[i] = inp[i];
            unchecked {
                i++;
            }
        }
        out[length] = element;
    }

    function appendHead(address[] memory inp, address element) internal pure returns (address[] memory out) {
        uint256 length = inp.length;
        out = new address[](length + 1);
        out[0] = element;
        for (uint256 i = 1; i <= length; ) {
            out[i] = inp[i - 1];
            unchecked {
                i++;
            }
        }
    }

    /**
     * @dev This function assumes a and b each contains unidentical elements
     * @param a array of addresses a
     * @param b array of addresses b
     * @return out Concatenation of a and b containing unidentical elements
     */
    function merge(address[] memory a, address[] memory b) internal pure returns (address[] memory out) {
        unchecked {
            uint256 countUnidenticalB = 0;
            bool[] memory isUnidentical = new bool[](b.length);
            for (uint256 i = 0; i < b.length; ++i) {
                if (!contains(a, b[i])) {
                    countUnidenticalB++;
                    isUnidentical[i] = true;
                }
            }

            out = new address[](a.length + countUnidenticalB);
            for (uint256 i = 0; i < a.length; ++i) {
                out[i] = a[i];
            }
            uint256 id = a.length;
            for (uint256 i = 0; i < b.length; ++i) {
                if (isUnidentical[i]) {
                    out[id++] = b[i];
                }
            }
        }
    }

    // various version of contains
    function contains(address[] memory array, address element) internal pure returns (bool) {
        uint256 length = array.length;
        for (uint256 i = 0; i < length; ) {
            if (array[i] == element) return true;
            unchecked {
                i++;
            }
        }
        return false;
    }

    function contains(bytes4[] memory array, bytes4 element) internal pure returns (bool) {
        uint256 length = array.length;
        for (uint256 i = 0; i < length; ) {
            if (array[i] == element) return true;
            unchecked {
                i++;
            }
        }
        return false;
    }

    function create(address a) internal pure returns (address[] memory res) {
        res = new address[](1);
        res[0] = a;
    }

    function create(address a, address b) internal pure returns (address[] memory res) {
        res = new address[](2);
        res[0] = a;
        res[1] = b;
    }

    function create(address a, address b, address c) internal pure returns (address[] memory res) {
        res = new address[](3);
        res[0] = a;
        res[1] = b;
        res[2] = c;
    }

    function create(address a, address b, address c, address d) internal pure returns (address[] memory res) {
        res = new address[](4);
        res[0] = a;
        res[1] = b;
        res[2] = c;
        res[3] = d;
    }

    function create(
        address a,
        address b,
        address c,
        address d,
        address e
    ) internal pure returns (address[] memory res) {
        res = new address[](5);
        res[0] = a;
        res[1] = b;
        res[2] = c;
        res[3] = d;
        res[4] = e;
    }

    function create(uint256 a) internal pure returns (uint256[] memory res) {
        res = new uint256[](1);
        res[0] = a;
    }
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

contract BoringOwnableUpgradeableData {
    address public owner;
    address public pendingOwner;
}

abstract contract BoringOwnableUpgradeable is BoringOwnableUpgradeableData, Initializable {
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    function __BoringOwnable_init() internal onlyInitializing {
        owner = msg.sender;
    }

    /// @notice Transfers ownership to `newOwner`. Either directly or claimable by the new pending owner.
    /// Can only be invoked by the current `owner`.
    /// @param newOwner Address of the new owner.
    /// @param direct True if `newOwner` should be set immediately. False if `newOwner` needs to use `claimOwnership`.
    /// @param renounce Allows the `newOwner` to be `address(0)` if `direct` and `renounce` is True. Has no effect otherwise.
    function transferOwnership(address newOwner, bool direct, bool renounce) public onlyOwner {
        if (direct) {
            // Checks
            require(newOwner != address(0) || renounce, "Ownable: zero address");

            // Effects
            emit OwnershipTransferred(owner, newOwner);
            owner = newOwner;
            pendingOwner = address(0);
        } else {
            // Effects
            pendingOwner = newOwner;
        }
    }

    /// @notice Needs to be called by `pendingOwner` to claim ownership.
    function claimOwnership() public {
        address _pendingOwner = pendingOwner;

        // Checks
        require(msg.sender == _pendingOwner, "Ownable: caller != pending owner");

        // Effects
        emit OwnershipTransferred(owner, _pendingOwner);
        owner = _pendingOwner;
        pendingOwner = address(0);
    }

    /// @notice Only allows the `owner` to execute the function.
    modifier onlyOwner() {
        require(msg.sender == owner, "Ownable: caller is not the owner");
        _;
    }

    uint256[48] private __gap;
}

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

pragma solidity ^0.8.0;

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

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

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

pragma solidity ^0.8.0;

/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 */
library Counters {
    struct Counter {
        // This variable should never be directly accessed by users of the library: interactions must be restricted to
        // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
        // this feature: see https://github.com/ethereum/solidity/issues/4637
        uint256 _value; // default: 0
    }

    function current(Counter storage counter) internal view returns (uint256) {
        return counter._value;
    }

    function increment(Counter storage counter) internal {
        unchecked {
            counter._value += 1;
        }
    }

    function decrement(Counter storage counter) internal {
        uint256 value = counter._value;
        require(value > 0, "Counter: decrement overflow");
        unchecked {
            counter._value = value - 1;
        }
    }

    function reset(Counter storage counter) internal {
        counter._value = 0;
    }
}

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

pragma solidity ^0.8.0;

import "../Strings.sol";

/**
 * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
 *
 * These functions can be used to verify that a message was signed by the holder
 * of the private keys of a given address.
 */
library ECDSA {
    enum RecoverError {
        NoError,
        InvalidSignature,
        InvalidSignatureLength,
        InvalidSignatureS,
        InvalidSignatureV // Deprecated in v4.8
    }

    function _throwError(RecoverError error) private pure {
        if (error == RecoverError.NoError) {
            return; // no error: do nothing
        } else if (error == RecoverError.InvalidSignature) {
            revert("ECDSA: invalid signature");
        } else if (error == RecoverError.InvalidSignatureLength) {
            revert("ECDSA: invalid signature length");
        } else if (error == RecoverError.InvalidSignatureS) {
            revert("ECDSA: invalid signature 's' value");
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature` or error string. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     *
     * Documentation for signature generation:
     * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
     * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
        if (signature.length == 65) {
            bytes32 r;
            bytes32 s;
            uint8 v;
            // ecrecover takes the signature parameters, and the only way to get them
            // currently is to use assembly.
            /// @solidity memory-safe-assembly
            assembly {
                r := mload(add(signature, 0x20))
                s := mload(add(signature, 0x40))
                v := byte(0, mload(add(signature, 0x60)))
            }
            return tryRecover(hash, v, r, s);
        } else {
            return (address(0), RecoverError.InvalidSignatureLength);
        }
    }

    /**
     * @dev Returns the address that signed a hashed message (`hash`) with
     * `signature`. This address can then be used for verification purposes.
     *
     * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
     * this function rejects them by requiring the `s` value to be in the lower
     * half order, and the `v` value to be either 27 or 28.
     *
     * IMPORTANT: `hash` _must_ be the result of a hash operation for the
     * verification to be secure: it is possible to craft signatures that
     * recover to arbitrary addresses for non-hashed data. A safe way to ensure
     * this is by receiving a hash of the original message (which may otherwise
     * be too long), and then calling {toEthSignedMessageHash} on it.
     */
    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, signature);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
     *
     * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
        uint8 v = uint8((uint256(vs) >> 255) + 27);
        return tryRecover(hash, v, r, s);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
     *
     * _Available since v4.2._
     */
    function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, r, vs);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
     * `r` and `s` signature fields separately.
     *
     * _Available since v4.3._
     */
    function tryRecover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address, RecoverError) {
        // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
        // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
        // the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
        // signatures from current libraries generate a unique signature with an s-value in the lower half order.
        //
        // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
        // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
        // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
        // these malleable signatures as well.
        if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
            return (address(0), RecoverError.InvalidSignatureS);
        }

        // If the signature is valid (and not malleable), return the signer address
        address signer = ecrecover(hash, v, r, s);
        if (signer == address(0)) {
            return (address(0), RecoverError.InvalidSignature);
        }

        return (signer, RecoverError.NoError);
    }

    /**
     * @dev Overload of {ECDSA-recover} that receives the `v`,
     * `r` and `s` signature fields separately.
     */
    function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
        (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
        _throwError(error);
        return recovered;
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from a `hash`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32 message) {
        // 32 is the length in bytes of hash,
        // enforced by the type signature above
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, "\x19Ethereum Signed Message:\n32")
            mstore(0x1c, hash)
            message := keccak256(0x00, 0x3c)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Message, created from `s`. This
     * produces hash corresponding to the one signed with the
     * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
     * JSON-RPC method as part of EIP-191.
     *
     * See {recover}.
     */
    function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
    }

    /**
     * @dev Returns an Ethereum Signed Typed Data, created from a
     * `domainSeparator` and a `structHash`. This produces hash corresponding
     * to the one signed with the
     * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
     * JSON-RPC method as part of EIP-712.
     *
     * See {recover}.
     */
    function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32 data) {
        /// @solidity memory-safe-assembly
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, "\x19\x01")
            mstore(add(ptr, 0x02), domainSeparator)
            mstore(add(ptr, 0x22), structHash)
            data := keccak256(ptr, 0x42)
        }
    }

    /**
     * @dev Returns an Ethereum Signed Data with intended validator, created from a
     * `validator` and `data` according to the version 0 of EIP-191.
     *
     * See {recover}.
     */
    function toDataWithIntendedValidatorHash(address validator, bytes memory data) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked("\x19\x00", validator, data));
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/cryptography/EIP712.sol)

pragma solidity ^0.8.8;

import "./ECDSA.sol";
import "../ShortStrings.sol";
import "../../interfaces/IERC5267.sol";

/**
 * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.
 *
 * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,
 * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding
 * they need in their contracts using a combination of `abi.encode` and `keccak256`.
 *
 * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding
 * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA
 * ({_hashTypedDataV4}).
 *
 * The implementation of the domain separator was designed to be as efficient as possible while still properly updating
 * the chain id to protect against replay attacks on an eventual fork of the chain.
 *
 * NOTE: This contract implements the version of the encoding known as "v4", as implemented by the JSON RPC method
 * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].
 *
 * NOTE: In the upgradeable version of this contract, the cached values will correspond to the address, and the domain
 * separator of the implementation contract. This will cause the `_domainSeparatorV4` function to always rebuild the
 * separator from the immutable values, which is cheaper than accessing a cached version in cold storage.
 *
 * _Available since v3.4._
 *
 * @custom:oz-upgrades-unsafe-allow state-variable-immutable state-variable-assignment
 */
abstract contract EIP712 is IERC5267 {
    using ShortStrings for *;

    bytes32 private constant _TYPE_HASH =
        keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");

    // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to
    // invalidate the cached domain separator if the chain id changes.
    bytes32 private immutable _cachedDomainSeparator;
    uint256 private immutable _cachedChainId;
    address private immutable _cachedThis;

    bytes32 private immutable _hashedName;
    bytes32 private immutable _hashedVersion;

    ShortString private immutable _name;
    ShortString private immutable _version;
    string private _nameFallback;
    string private _versionFallback;

    /**
     * @dev Initializes the domain separator and parameter caches.
     *
     * The meaning of `name` and `version` is specified in
     * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:
     *
     * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.
     * - `version`: the current major version of the signing domain.
     *
     * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart
     * contract upgrade].
     */
    constructor(string memory name, string memory version) {
        _name = name.toShortStringWithFallback(_nameFallback);
        _version = version.toShortStringWithFallback(_versionFallback);
        _hashedName = keccak256(bytes(name));
        _hashedVersion = keccak256(bytes(version));

        _cachedChainId = block.chainid;
        _cachedDomainSeparator = _buildDomainSeparator();
        _cachedThis = address(this);
    }

    /**
     * @dev Returns the domain separator for the current chain.
     */
    function _domainSeparatorV4() internal view returns (bytes32) {
        if (address(this) == _cachedThis && block.chainid == _cachedChainId) {
            return _cachedDomainSeparator;
        } else {
            return _buildDomainSeparator();
        }
    }

    function _buildDomainSeparator() private view returns (bytes32) {
        return keccak256(abi.encode(_TYPE_HASH, _hashedName, _hashedVersion, block.chainid, address(this)));
    }

    /**
     * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
     * function returns the hash of the fully encoded EIP712 message for this domain.
     *
     * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
     *
     * ```solidity
     * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(
     *     keccak256("Mail(address to,string contents)"),
     *     mailTo,
     *     keccak256(bytes(mailContents))
     * )));
     * address signer = ECDSA.recover(digest, signature);
     * ```
     */
    function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {
        return ECDSA.toTypedDataHash(_domainSeparatorV4(), structHash);
    }

    /**
     * @dev See {EIP-5267}.
     *
     * _Available since v4.9._
     */
    function eip712Domain()
        public
        view
        virtual
        override
        returns (
            bytes1 fields,
            string memory name,
            string memory version,
            uint256 chainId,
            address verifyingContract,
            bytes32 salt,
            uint256[] memory extensions
        )
    {
        return (
            hex"0f", // 01111
            _name.toStringWithFallback(_nameFallback),
            _version.toStringWithFallback(_versionFallback),
            block.chainid,
            address(this),
            bytes32(0),
            new uint256[](0)
        );
    }
}

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

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

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

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/ERC20Permit.sol)

pragma solidity ^0.8.0;

import "./IERC20Permit.sol";
import "../ERC20.sol";
import "../../../utils/cryptography/ECDSA.sol";
import "../../../utils/cryptography/EIP712.sol";
import "../../../utils/Counters.sol";

/**
 * @dev Implementation 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.
 *
 * _Available since v3.4._
 */
abstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {
    using Counters for Counters.Counter;

    mapping(address => Counters.Counter) private _nonces;

    // solhint-disable-next-line var-name-mixedcase
    bytes32 private constant _PERMIT_TYPEHASH =
        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    /**
     * @dev In previous versions `_PERMIT_TYPEHASH` was declared as `immutable`.
     * However, to ensure consistency with the upgradeable transpiler, we will continue
     * to reserve a slot.
     * @custom:oz-renamed-from _PERMIT_TYPEHASH
     */
    // solhint-disable-next-line var-name-mixedcase
    bytes32 private _PERMIT_TYPEHASH_DEPRECATED_SLOT;

    /**
     * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `"1"`.
     *
     * It's a good idea to use the same `name` that is defined as the ERC20 token name.
     */
    constructor(string memory name) EIP712(name, "1") {}

    /**
     * @dev See {IERC20Permit-permit}.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        require(block.timestamp <= deadline, "ERC20Permit: expired deadline");

        bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));

        bytes32 hash = _hashTypedDataV4(structHash);

        address signer = ECDSA.recover(hash, v, r, s);
        require(signer == owner, "ERC20Permit: invalid signature");

        _approve(owner, spender, value);
    }

    /**
     * @dev See {IERC20Permit-nonces}.
     */
    function nonces(address owner) public view virtual override returns (uint256) {
        return _nonces[owner].current();
    }

    /**
     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
        return _domainSeparatorV4();
    }

    /**
     * @dev "Consume a nonce": return the current value and increment.
     *
     * _Available since v4.1._
     */
    function _useNonce(address owner) internal virtual returns (uint256 current) {
        Counters.Counter storage nonce = _nonces[owner];
        current = nonce.current();
        nonce.increment();
    }
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

library Errors {
    // BulkSeller
    error BulkInsufficientSyForTrade(uint256 currentAmount, uint256 requiredAmount);
    error BulkInsufficientTokenForTrade(uint256 currentAmount, uint256 requiredAmount);
    error BulkInSufficientSyOut(uint256 actualSyOut, uint256 requiredSyOut);
    error BulkInSufficientTokenOut(uint256 actualTokenOut, uint256 requiredTokenOut);
    error BulkInsufficientSyReceived(uint256 actualBalance, uint256 requiredBalance);
    error BulkNotMaintainer();
    error BulkNotAdmin();
    error BulkSellerAlreadyExisted(address token, address SY, address bulk);
    error BulkSellerInvalidToken(address token, address SY);
    error BulkBadRateTokenToSy(uint256 actualRate, uint256 currentRate, uint256 eps);
    error BulkBadRateSyToToken(uint256 actualRate, uint256 currentRate, uint256 eps);

    // APPROX
    error ApproxFail();
    error ApproxParamsInvalid(uint256 guessMin, uint256 guessMax, uint256 eps);
    error ApproxBinarySearchInputInvalid(
        uint256 approxGuessMin,
        uint256 approxGuessMax,
        uint256 minGuessMin,
        uint256 maxGuessMax
    );

    // MARKET + MARKET MATH CORE
    error MarketExpired();
    error MarketZeroAmountsInput();
    error MarketZeroAmountsOutput();
    error MarketZeroLnImpliedRate();
    error MarketInsufficientPtForTrade(int256 currentAmount, int256 requiredAmount);
    error MarketInsufficientPtReceived(uint256 actualBalance, uint256 requiredBalance);
    error MarketInsufficientSyReceived(uint256 actualBalance, uint256 requiredBalance);
    error MarketZeroTotalPtOrTotalAsset(int256 totalPt, int256 totalAsset);
    error MarketExchangeRateBelowOne(int256 exchangeRate);
    error MarketProportionMustNotEqualOne();
    error MarketRateScalarBelowZero(int256 rateScalar);
    error MarketScalarRootBelowZero(int256 scalarRoot);
    error MarketProportionTooHigh(int256 proportion, int256 maxProportion);

    error OracleUninitialized();
    error OracleTargetTooOld(uint32 target, uint32 oldest);
    error OracleZeroCardinality();

    error MarketFactoryExpiredPt();
    error MarketFactoryInvalidPt();
    error MarketFactoryMarketExists();

    error MarketFactoryLnFeeRateRootTooHigh(uint80 lnFeeRateRoot, uint256 maxLnFeeRateRoot);
    error MarketFactoryOverriddenFeeTooHigh(uint80 overriddenFee, uint256 marketLnFeeRateRoot);
    error MarketFactoryReserveFeePercentTooHigh(uint8 reserveFeePercent, uint8 maxReserveFeePercent);
    error MarketFactoryZeroTreasury();
    error MarketFactoryInitialAnchorTooLow(int256 initialAnchor, int256 minInitialAnchor);
    error MFNotPendleMarket(address addr);

    // ROUTER
    error RouterInsufficientLpOut(uint256 actualLpOut, uint256 requiredLpOut);
    error RouterInsufficientSyOut(uint256 actualSyOut, uint256 requiredSyOut);
    error RouterInsufficientPtOut(uint256 actualPtOut, uint256 requiredPtOut);
    error RouterInsufficientYtOut(uint256 actualYtOut, uint256 requiredYtOut);
    error RouterInsufficientPYOut(uint256 actualPYOut, uint256 requiredPYOut);
    error RouterInsufficientTokenOut(uint256 actualTokenOut, uint256 requiredTokenOut);
    error RouterInsufficientSyRepay(uint256 actualSyRepay, uint256 requiredSyRepay);
    error RouterInsufficientPtRepay(uint256 actualPtRepay, uint256 requiredPtRepay);
    error RouterNotAllSyUsed(uint256 netSyDesired, uint256 netSyUsed);

    error RouterTimeRangeZero();
    error RouterCallbackNotPendleMarket(address caller);
    error RouterInvalidAction(bytes4 selector);
    error RouterInvalidFacet(address facet);

    error RouterKyberSwapDataZero();

    error SimulationResults(bool success, bytes res);

    // YIELD CONTRACT
    error YCExpired();
    error YCNotExpired();
    error YieldContractInsufficientSy(uint256 actualSy, uint256 requiredSy);
    error YCNothingToRedeem();
    error YCPostExpiryDataNotSet();
    error YCNoFloatingSy();

    // YieldFactory
    error YCFactoryInvalidExpiry();
    error YCFactoryYieldContractExisted();
    error YCFactoryZeroExpiryDivisor();
    error YCFactoryZeroTreasury();
    error YCFactoryInterestFeeRateTooHigh(uint256 interestFeeRate, uint256 maxInterestFeeRate);
    error YCFactoryRewardFeeRateTooHigh(uint256 newRewardFeeRate, uint256 maxRewardFeeRate);

    // SY
    error SYInvalidTokenIn(address token);
    error SYInvalidTokenOut(address token);
    error SYZeroDeposit();
    error SYZeroRedeem();
    error SYInsufficientSharesOut(uint256 actualSharesOut, uint256 requiredSharesOut);
    error SYInsufficientTokenOut(uint256 actualTokenOut, uint256 requiredTokenOut);

    // SY-specific
    error SYQiTokenMintFailed(uint256 errCode);
    error SYQiTokenRedeemFailed(uint256 errCode);
    error SYQiTokenRedeemRewardsFailed(uint256 rewardAccruedType0, uint256 rewardAccruedType1);
    error SYQiTokenBorrowRateTooHigh(uint256 borrowRate, uint256 borrowRateMax);

    error SYCurveInvalidPid();
    error SYCurve3crvPoolNotFound();

    error SYApeDepositAmountTooSmall(uint256 amountDeposited);
    error SYBalancerInvalidPid();
    error SYInvalidRewardToken(address token);

    error SYStargateRedeemCapExceeded(uint256 amountLpDesired, uint256 amountLpRedeemable);

    error SYBalancerReentrancy();

    error NotFromTrustedRemote(uint16 srcChainId, bytes path);

    error ApxETHNotEnoughBuffer();

    // Liquidity Mining
    error VCInactivePool(address pool);
    error VCPoolAlreadyActive(address pool);
    error VCZeroVePendle(address user);
    error VCExceededMaxWeight(uint256 totalWeight, uint256 maxWeight);
    error VCEpochNotFinalized(uint256 wTime);
    error VCPoolAlreadyAddAndRemoved(address pool);

    error VEInvalidNewExpiry(uint256 newExpiry);
    error VEExceededMaxLockTime();
    error VEInsufficientLockTime();
    error VENotAllowedReduceExpiry();
    error VEZeroAmountLocked();
    error VEPositionNotExpired();
    error VEZeroPosition();
    error VEZeroSlope(uint128 bias, uint128 slope);
    error VEReceiveOldSupply(uint256 msgTime);

    error GCNotPendleMarket(address caller);
    error GCNotVotingController(address caller);

    error InvalidWTime(uint256 wTime);
    error ExpiryInThePast(uint256 expiry);
    error ChainNotSupported(uint256 chainId);

    error FDTotalAmountFundedNotMatch(uint256 actualTotalAmount, uint256 expectedTotalAmount);
    error FDEpochLengthMismatch();
    error FDInvalidPool(address pool);
    error FDPoolAlreadyExists(address pool);
    error FDInvalidNewFinishedEpoch(uint256 oldFinishedEpoch, uint256 newFinishedEpoch);
    error FDInvalidStartEpoch(uint256 startEpoch);
    error FDInvalidWTimeFund(uint256 lastFunded, uint256 wTime);
    error FDFutureFunding(uint256 lastFunded, uint256 currentWTime);

    error BDInvalidEpoch(uint256 epoch, uint256 startTime);

    // Cross-Chain
    error MsgNotFromSendEndpoint(uint16 srcChainId, bytes path);
    error MsgNotFromReceiveEndpoint(address sender);
    error InsufficientFeeToSendMsg(uint256 currentFee, uint256 requiredFee);
    error ApproxDstExecutionGasNotSet();
    error InvalidRetryData();

    // GENERIC MSG
    error ArrayLengthMismatch();
    error ArrayEmpty();
    error ArrayOutOfBounds();
    error ZeroAddress();
    error FailedToSendEther();
    error InvalidMerkleProof();

    error OnlyLayerZeroEndpoint();
    error OnlyYT();
    error OnlyYCFactory();
    error OnlyWhitelisted();

    // Swap Aggregator
    error SAInsufficientTokenIn(address tokenIn, uint256 amountExpected, uint256 amountActual);
    error UnsupportedSelector(uint256 aggregatorType, bytes4 selector);
}

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

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

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

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

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

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

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

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

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

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

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @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 IERC20Permit {
    /**
     * @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) (interfaces/IERC5267.sol)

pragma solidity ^0.8.0;

interface IERC5267 {
    /**
     * @dev MAY be emitted to signal that the domain could have changed.
     */
    event EIP712DomainChanged();

    /**
     * @dev returns the fields and values that describe the domain separator used by this contract for EIP-712
     * signature.
     */
    function eip712Domain()
        external
        view
        returns (
            bytes1 fields,
            string memory name,
            string memory version,
            uint256 chainId,
            address verifyingContract,
            bytes32 salt,
            uint256[] memory extensions
        );
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

interface IRewardManager {
    function userReward(address token, address user) external view returns (uint128 index, uint128 accrued);
}

// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.0;

interface ISkyConverter {
    function daiToUsds(address usr, uint256 wad) external;

    function usdsToDai(address usr, uint256 wad) external;
}

// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.0;

interface ISkyStaking {
    function stake(uint256 amount) external;

    function withdraw(uint256 amount) external;

    function getReward() external;
}

// SPDX-License-Identifier: GPL-3.0-or-later
/*
 * MIT License
 * ===========
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 */

pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

interface IStandardizedYield is IERC20Metadata {
    /// @dev Emitted when any base tokens is deposited to mint shares
    event Deposit(
        address indexed caller,
        address indexed receiver,
        address indexed tokenIn,
        uint256 amountDeposited,
        uint256 amountSyOut
    );

    /// @dev Emitted when any shares are redeemed for base tokens
    event Redeem(
        address indexed caller,
        address indexed receiver,
        address indexed tokenOut,
        uint256 amountSyToRedeem,
        uint256 amountTokenOut
    );

    /// @dev check `assetInfo()` for more information
    enum AssetType {
        TOKEN,
        LIQUIDITY
    }

    /// @dev Emitted when (`user`) claims their rewards
    event ClaimRewards(address indexed user, address[] rewardTokens, uint256[] rewardAmounts);

    /**
     * @notice mints an amount of shares by depositing a base token.
     * @param receiver shares recipient address
     * @param tokenIn address of the base tokens to mint shares
     * @param amountTokenToDeposit amount of base tokens to be transferred from (`msg.sender`)
     * @param minSharesOut reverts if amount of shares minted is lower than this
     * @return amountSharesOut amount of shares minted
     * @dev Emits a {Deposit} event
     *
     * Requirements:
     * - (`tokenIn`) must be a valid base token.
     */
    function deposit(
        address receiver,
        address tokenIn,
        uint256 amountTokenToDeposit,
        uint256 minSharesOut
    ) external payable returns (uint256 amountSharesOut);

    /**
     * @notice redeems an amount of base tokens by burning some shares
     * @param receiver recipient address
     * @param amountSharesToRedeem amount of shares to be burned
     * @param tokenOut address of the base token to be redeemed
     * @param minTokenOut reverts if amount of base token redeemed is lower than this
     * @param burnFromInternalBalance if true, burns from balance of `address(this)`, otherwise burns from `msg.sender`
     * @return amountTokenOut amount of base tokens redeemed
     * @dev Emits a {Redeem} event
     *
     * Requirements:
     * - (`tokenOut`) must be a valid base token.
     */
    function redeem(
        address receiver,
        uint256 amountSharesToRedeem,
        address tokenOut,
        uint256 minTokenOut,
        bool burnFromInternalBalance
    ) external returns (uint256 amountTokenOut);

    /**
     * @notice exchangeRate * syBalance / 1e18 must return the asset balance of the account
     * @notice vice-versa, if a user uses some amount of tokens equivalent to X asset, the amount of sy
     he can mint must be X * exchangeRate / 1e18
     * @dev SYUtils's assetToSy & syToAsset should be used instead of raw multiplication
     & division
     */
    function exchangeRate() external view returns (uint256 res);

    /**
     * @notice claims reward for (`user`)
     * @param user the user receiving their rewards
     * @return rewardAmounts an array of reward amounts in the same order as `getRewardTokens`
     * @dev
     * Emits a `ClaimRewards` event
     * See {getRewardTokens} for list of reward tokens
     */
    function claimRewards(address user) external returns (uint256[] memory rewardAmounts);

    /**
     * @notice get the amount of unclaimed rewards for (`user`)
     * @param user the user to check for
     * @return rewardAmounts an array of reward amounts in the same order as `getRewardTokens`
     */
    function accruedRewards(address user) external view returns (uint256[] memory rewardAmounts);

    function rewardIndexesCurrent() external returns (uint256[] memory indexes);

    function rewardIndexesStored() external view returns (uint256[] memory indexes);

    /**
     * @notice returns the list of reward token addresses
     */
    function getRewardTokens() external view returns (address[] memory);

    /**
     * @notice returns the address of the underlying yield token
     */
    function yieldToken() external view returns (address);

    /**
     * @notice returns all tokens that can mint this SY
     */
    function getTokensIn() external view returns (address[] memory res);

    /**
     * @notice returns all tokens that can be redeemed by this SY
     */
    function getTokensOut() external view returns (address[] memory res);

    function isValidTokenIn(address token) external view returns (bool);

    function isValidTokenOut(address token) external view returns (bool);

    function previewDeposit(
        address tokenIn,
        uint256 amountTokenToDeposit
    ) external view returns (uint256 amountSharesOut);

    function previewRedeem(
        address tokenOut,
        uint256 amountSharesToRedeem
    ) external view returns (uint256 amountTokenOut);

    /**
     * @notice This function contains information to interpret what the asset is
     * @return assetType the type of the asset (0 for ERC20 tokens, 1 for AMM liquidity tokens,
        2 for bridged yield bearing tokens like wstETH, rETH on Arbi whose the underlying asset doesn't exist on the chain)
     * @return assetAddress the address of the asset
     * @return assetDecimals the decimals of the asset
     */
    function assetInfo() external view returns (AssetType assetType, address assetAddress, uint8 assetDecimals);
}

// SPDX-License-Identifier: GPL-3.0-or-later
/*
 * MIT License
 * ===========
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 */
pragma solidity ^0.8.0;

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

interface IWETH is IERC20 {
    event Deposit(address indexed dst, uint256 wad);
    event Withdrawal(address indexed src, uint256 wad);

    function deposit() external payable;

    function withdraw(uint256 wad) 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) (utils/math/Math.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.8.0;

/* solhint-disable private-vars-leading-underscore, reason-string */

library PMath {
    uint256 internal constant ONE = 1e18; // 18 decimal places
    int256 internal constant IONE = 1e18; // 18 decimal places

    function subMax0(uint256 a, uint256 b) internal pure returns (uint256) {
        unchecked {
            return (a >= b ? a - b : 0);
        }
    }

    function subNoNeg(int256 a, int256 b) internal pure returns (int256) {
        require(a >= b, "negative");
        return a - b; // no unchecked since if b is very negative, a - b might overflow
    }

    function mulDown(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 product = a * b;
        unchecked {
            return product / ONE;
        }
    }

    function mulDown(int256 a, int256 b) internal pure returns (int256) {
        int256 product = a * b;
        unchecked {
            return product / IONE;
        }
    }

    function divDown(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 aInflated = a * ONE;
        unchecked {
            return aInflated / b;
        }
    }

    function divDown(int256 a, int256 b) internal pure returns (int256) {
        int256 aInflated = a * IONE;
        unchecked {
            return aInflated / b;
        }
    }

    function rawDivUp(uint256 a, uint256 b) internal pure returns (uint256) {
        return (a + b - 1) / b;
    }

    function rawDivUp(int256 a, int256 b) internal pure returns (int256) {
        return (a + b - 1) / b;
    }

    function slipUp(uint256 a, uint256 factor) internal pure returns (uint256) {
        return mulDown(a, ONE + factor);
    }

    function slipDown(uint256 a, uint256 factor) internal pure returns (uint256) {
        return mulDown(a, ONE - factor);
    }

    // @author Uniswap
    function sqrt(uint256 y) internal pure returns (uint256 z) {
        if (y > 3) {
            z = y;
            uint256 x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }

    function square(uint256 x) internal pure returns (uint256) {
        return x * x;
    }

    function squareDown(uint256 x) internal pure returns (uint256) {
        return mulDown(x, x);
    }

    function abs(int256 x) internal pure returns (uint256) {
        return uint256(x > 0 ? x : -x);
    }

    function neg(int256 x) internal pure returns (int256) {
        return x * (-1);
    }

    function neg(uint256 x) internal pure returns (int256) {
        return Int(x) * (-1);
    }

    function max(uint256 x, uint256 y) internal pure returns (uint256) {
        return (x > y ? x : y);
    }

    function max(int256 x, int256 y) internal pure returns (int256) {
        return (x > y ? x : y);
    }

    function min(uint256 x, uint256 y) internal pure returns (uint256) {
        return (x < y ? x : y);
    }

    function min(int256 x, int256 y) internal pure returns (int256) {
        return (x < y ? x : y);
    }

    /*///////////////////////////////////////////////////////////////
                               SIGNED CASTS
    //////////////////////////////////////////////////////////////*/

    function Int(uint256 x) internal pure returns (int256) {
        require(x <= uint256(type(int256).max));
        return int256(x);
    }

    function Int128(int256 x) internal pure returns (int128) {
        require(type(int128).min <= x && x <= type(int128).max);
        return int128(x);
    }

    function Int128(uint256 x) internal pure returns (int128) {
        return Int128(Int(x));
    }

    /*///////////////////////////////////////////////////////////////
                               UNSIGNED CASTS
    //////////////////////////////////////////////////////////////*/

    function Uint(int256 x) internal pure returns (uint256) {
        require(x >= 0);
        return uint256(x);
    }

    function Uint32(uint256 x) internal pure returns (uint32) {
        require(x <= type(uint32).max);
        return uint32(x);
    }

    function Uint64(uint256 x) internal pure returns (uint64) {
        require(x <= type(uint64).max);
        return uint64(x);
    }

    function Uint112(uint256 x) internal pure returns (uint112) {
        require(x <= type(uint112).max);
        return uint112(x);
    }

    function Uint96(uint256 x) internal pure returns (uint96) {
        require(x <= type(uint96).max);
        return uint96(x);
    }

    function Uint128(uint256 x) internal pure returns (uint128) {
        require(x <= type(uint128).max);
        return uint128(x);
    }

    function Uint192(uint256 x) internal pure returns (uint192) {
        require(x <= type(uint192).max);
        return uint192(x);
    }

    function isAApproxB(uint256 a, uint256 b, uint256 eps) internal pure returns (bool) {
        return mulDown(b, ONE - eps) <= a && a <= mulDown(b, ONE + eps);
    }

    function isAGreaterApproxB(uint256 a, uint256 b, uint256 eps) internal pure returns (bool) {
        return a >= b && a <= mulDown(b, ONE + eps);
    }

    function isASmallerApproxB(uint256 a, uint256 b, uint256 eps) internal pure returns (bool) {
        return a <= b && a >= mulDown(b, ONE - eps);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)

pragma solidity ^0.8.0;

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

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        _requireNotPaused();
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        _requirePaused();
        _;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Throws if the contract is paused.
     */
    function _requireNotPaused() internal view virtual {
        require(!paused(), "Pausable: paused");
    }

    /**
     * @dev Throws if the contract is not paused.
     */
    function _requirePaused() internal view virtual {
        require(paused(), "Pausable: not paused");
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// SPDX-License-Identifier: GPL-3.0-or-later
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/utils/Context.sol";

/**
 * @dev Pendle's ERC20 implementation, modified from @openzeppelin implementation
 * Changes are:
 * - comes with built-in reentrancy protection, storage-packed with totalSupply variable
 * - delete increaseAllowance / decreaseAllowance
 * - add nonReentrancy protection to transfer / transferFrom functions
 * - allow decimals to be passed in
 * - block self-transfer by default
 */
// solhint-disable
contract PendleERC20 is Context, IERC20, IERC20Metadata {
    uint8 private constant _NOT_ENTERED = 1;
    uint8 private constant _ENTERED = 2;

    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint248 private _totalSupply;
    uint8 private _status;

    string private _name;
    string private _symbol;
    uint8 public immutable decimals;

    /**
     * @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() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

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

        _;

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

    /**
     * @dev Sets the values for {name}, {symbol} and {decimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_, uint8 decimals_) {
        _name = name_;
        _symbol = symbol_;
        decimals = decimals_;
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

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

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) external virtual override nonReentrant returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) external virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external virtual override nonReentrant returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(address from, address to, uint256 amount) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(from != to, "ERC20: transfer to self");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += toUint248(amount);
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= toUint248(amount);

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}

    function toUint248(uint256 x) internal virtual returns (uint248) {
        require(x <= type(uint248).max); // signed, lim = bit-1
        return uint248(x);
    }
}

// SPDX-License-Identifier: GPL-3.0-or-later
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./PendleERC20.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20Permit.sol";
import "@openzeppelin/contracts/utils/cryptography/draft-EIP712.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/Counters.sol";

/// @dev forked from OZ's ERC20Permit
contract PendleERC20Permit is PendleERC20, IERC20Permit, EIP712 {
    using Counters for Counters.Counter;

    mapping(address => Counters.Counter) private _nonces;

    // solhint-disable-next-line var-name-mixedcase
    bytes32 private constant _PERMIT_TYPEHASH =
        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");

    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_
    ) PendleERC20(name_, symbol_, decimals_) EIP712(name_, "1") {}

    /**
     * @dev See {IERC20Permit-permit}.
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual override {
        require(block.timestamp <= deadline, "ERC20Permit: expired deadline");

        bytes32 structHash = keccak256(abi.encode(_PERMIT_TYPEHASH, owner, spender, value, _useNonce(owner), deadline));

        bytes32 hash = _hashTypedDataV4(structHash);

        address signer = ECDSA.recover(hash, v, r, s);
        require(signer == owner, "ERC20Permit: invalid signature");

        _approve(owner, spender, value);
    }

    /**
     * @dev See {IERC20Permit-nonces}.
     */
    function nonces(address owner) public view virtual override returns (uint256) {
        return _nonces[owner].current();
    }

    /**
     * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.
     */
    // solhint-disable-next-line func-name-mixedcase
    function DOMAIN_SEPARATOR() external view override returns (bytes32) {
        return _domainSeparatorV4();
    }

    /**
     * @dev "Consume a nonce": return the current value and increment.
     *
     * _Available since v4.1._
     */
    function _useNonce(address owner) internal virtual returns (uint256 current) {
        Counters.Counter storage nonce = _nonces[owner];
        current = nonce.current();
        nonce.increment();
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

import "../../SYBaseWithRewards.sol";
import "../../../../interfaces/Sky/ISkyStaking.sol";
import "../../../../interfaces/Sky/ISkyConverter.sol";

contract PendleStakingUSDSSY is SYBaseWithRewards {
    address public constant CONVERTER = 0x3225737a9Bbb6473CB4a45b7244ACa2BeFdB276A;
    address public constant DAI = 0x6B175474E89094C44Da98b954EedeAC495271d0F;
    address public constant USDS = 0xdC035D45d973E3EC169d2276DDab16f1e407384F;
    address public constant SKY = 0x56072C95FAA701256059aa122697B133aDEd9279;
    address public immutable STAKING_CONTRACT = 0x0650CAF159C5A49f711e8169D4336ECB9b950275;

    constructor() SYBaseWithRewards("SY Staking USDS", "SY-staking-USDS", USDS) {
        _safeApproveInf(DAI, CONVERTER);
        _safeApproveInf(USDS, CONVERTER);
        _safeApproveInf(USDS, STAKING_CONTRACT);
    }

    function _deposit(
        address tokenIn,
        uint256 amountDeposited
    ) internal virtual override returns (uint256) {
        if (tokenIn == DAI) {
            ISkyConverter(CONVERTER).daiToUsds(address(this), amountDeposited);
        }
        ISkyStaking(STAKING_CONTRACT).stake(amountDeposited);
        return amountDeposited;
    }

    function _redeem(
        address receiver,
        address tokenOut,
        uint256 amountSharesToRedeem
    ) internal virtual override returns (uint256) {
        ISkyStaking(STAKING_CONTRACT).withdraw(amountSharesToRedeem);
        if (tokenOut == DAI) {
            ISkyConverter(CONVERTER).usdsToDai(receiver, amountSharesToRedeem);
        } else {
            _transferOut(USDS, receiver, amountSharesToRedeem);
        }
        return amountSharesToRedeem;
    }

    /*///////////////////////////////////////////////////////////////
                               EXCHANGE-RATE
    //////////////////////////////////////////////////////////////*/

    function exchangeRate() public view virtual override returns (uint256) {
        return PMath.ONE;
    }

    /*///////////////////////////////////////////////////////////////
                               REWARDS-RELATED
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev See {IStandardizedYield-getRewardTokens}
     */
    function _getRewardTokens() internal pure override returns (address[] memory) {
        return ArrayLib.create(SKY);
    }

    function _redeemExternalReward() internal override {
        ISkyStaking(STAKING_CONTRACT).getReward();
    }

    /*///////////////////////////////////////////////////////////////
                MISC FUNCTIONS FOR METADATA
    //////////////////////////////////////////////////////////////*/

    function _previewDeposit(
        address /*tokenIn*/,
        uint256 amountTokenToDeposit
    ) internal pure override returns (uint256 amountSharesOut) {
        return amountTokenToDeposit;
    }

    function _previewRedeem(
        address /*tokenOut*/,
        uint256 amountSharesToRedeem
    ) internal pure override returns (uint256 amountTokenOut) {
        return amountSharesToRedeem;
    }

    function getTokensIn() public view virtual override returns (address[] memory) {
        return ArrayLib.create(DAI, USDS);
    }

    function getTokensOut() public view virtual override returns (address[] memory) {
        return ArrayLib.create(DAI, USDS);
    }

    function isValidTokenIn(address token) public view virtual override returns (bool) {
        return token == DAI || token == USDS;
    }

    function isValidTokenOut(address token) public view virtual override returns (bool) {
        return token == DAI || token == USDS;
    }

    function assetInfo() external view returns (AssetType assetType, address assetAddress, uint8 assetDecimals) {
        return (AssetType.TOKEN, USDS, IERC20Metadata(USDS).decimals());
    }
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

import "./RewardManagerAbstract.sol";

/// NOTE: This RewardManager is used with SY & YTv2 & PendleMarket. For YTv1, it will use RewardManagerAbstract
/// NOTE: RewardManager must not have duplicated rewardTokens
abstract contract RewardManager is RewardManagerAbstract {
    using PMath for uint256;
    using ArrayLib for uint256[];

    uint256 public lastRewardBlock;

    mapping(address => RewardState) public rewardState;

    function _updateRewardIndex()
        internal
        virtual
        override
        returns (address[] memory tokens, uint256[] memory indexes)
    {
        tokens = _getRewardTokens();
        indexes = new uint256[](tokens.length);

        if (tokens.length == 0) return (tokens, indexes);

        if (lastRewardBlock != block.number) {
            // if we have not yet update the index for this block
            lastRewardBlock = block.number;

            uint256 totalShares = _rewardSharesTotal();

            _redeemExternalReward();

            for (uint256 i = 0; i < tokens.length; ++i) {
                address token = tokens[i];

                // the entire token balance of the contract must be the rewards of the contract

                RewardState memory _state = rewardState[token];
                (uint256 lastBalance, uint256 index) = (_state.lastBalance, _state.index);

                uint256 accrued = _selfBalance(tokens[i]) - lastBalance;

                if (index == 0) index = INITIAL_REWARD_INDEX;
                if (totalShares != 0) index += accrued.divDown(totalShares);

                rewardState[token] = RewardState({
                    index: index.Uint128(),
                    lastBalance: (lastBalance + accrued).Uint128()
                });
                indexes[i] = index;
            }
        } else {
            for (uint256 i = 0; i < tokens.length; i++) {
                indexes[i] = rewardState[tokens[i]].index;
            }
        }
    }

    /// @dev this function doesn't need redeemExternal since redeemExternal is bundled in updateRewardIndex
    /// @dev this function also has to update rewardState.lastBalance
    function _doTransferOutRewards(
        address user,
        address receiver
    ) internal virtual override returns (uint256[] memory rewardAmounts) {
        address[] memory tokens = _getRewardTokens();
        rewardAmounts = new uint256[](tokens.length);
        for (uint256 i = 0; i < tokens.length; i++) {
            rewardAmounts[i] = userReward[tokens[i]][user].accrued;
            if (rewardAmounts[i] != 0) {
                userReward[tokens[i]][user].accrued = 0;
                rewardState[tokens[i]].lastBalance -= rewardAmounts[i].Uint128();
                _transferOut(tokens[i], receiver, rewardAmounts[i]);
            }
        }
    }

    function _getRewardTokens() internal view virtual returns (address[] memory);

    function _rewardSharesTotal() internal view virtual returns (uint256);
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

import "../../interfaces/IRewardManager.sol";

import "../libraries/ArrayLib.sol";
import "../libraries/TokenHelper.sol";
import "../libraries/math/PMath.sol";

import "./RewardManagerAbstract.sol";

/// NOTE: RewardManager must not have duplicated rewardTokens
abstract contract RewardManagerAbstract is IRewardManager, TokenHelper {
    using PMath for uint256;

    uint256 internal constant INITIAL_REWARD_INDEX = 1;

    struct RewardState {
        uint128 index;
        uint128 lastBalance;
    }

    struct UserReward {
        uint128 index;
        uint128 accrued;
    }

    // [token] => [user] => (index,accrued)
    mapping(address => mapping(address => UserReward)) public userReward;

    function _updateAndDistributeRewards(address user) internal virtual {
        _updateAndDistributeRewardsForTwo(user, address(0));
    }

    function _updateAndDistributeRewardsForTwo(address user1, address user2) internal virtual {
        (address[] memory tokens, uint256[] memory indexes) = _updateRewardIndex();
        if (tokens.length == 0) return;

        if (user1 != address(0) && user1 != address(this)) _distributeRewardsPrivate(user1, tokens, indexes);
        if (user2 != address(0) && user2 != address(this)) _distributeRewardsPrivate(user2, tokens, indexes);
    }

    // should only be callable from `_updateAndDistributeRewardsForTwo` to guarantee user != address(0) && user != address(this)
    function _distributeRewardsPrivate(address user, address[] memory tokens, uint256[] memory indexes) private {
        assert(user != address(0) && user != address(this));

        uint256 userShares = _rewardSharesUser(user);

        for (uint256 i = 0; i < tokens.length; ++i) {
            address token = tokens[i];
            uint256 index = indexes[i];
            uint256 userIndex = userReward[token][user].index;

            if (userIndex == 0) {
                userIndex = INITIAL_REWARD_INDEX.Uint128();
            }

            if (userIndex == index || index == 0) continue;

            uint256 deltaIndex = index - userIndex;
            uint256 rewardDelta = userShares.mulDown(deltaIndex);
            uint256 rewardAccrued = userReward[token][user].accrued + rewardDelta;

            userReward[token][user] = UserReward({index: index.Uint128(), accrued: rewardAccrued.Uint128()});
        }
    }

    function _updateRewardIndex() internal virtual returns (address[] memory tokens, uint256[] memory indexes);

    function _redeemExternalReward() internal virtual;

    function _doTransferOutRewards(
        address user,
        address receiver
    ) internal virtual returns (uint256[] memory rewardAmounts);

    function _rewardSharesUser(address user) internal view virtual returns (uint256);
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;
import "../../interfaces/IStandardizedYield.sol";

import "../erc20/PendleERC20Permit.sol";

import "../libraries/math/PMath.sol";
import "../libraries/TokenHelper.sol";
import "../libraries/ArrayLib.sol";
import "../libraries/Errors.sol";
import "../libraries/BoringOwnableUpgradeable.sol";
import "@openzeppelin/contracts/security/Pausable.sol";

abstract contract SYBase is IStandardizedYield, PendleERC20Permit, TokenHelper, BoringOwnableUpgradeable, Pausable {
    using PMath for uint256;

    address public immutable yieldToken;

    constructor(
        string memory _name,
        string memory _symbol,
        address _yieldToken
    ) PendleERC20Permit(_name, _symbol, IERC20Metadata(_yieldToken).decimals()) initializer {
        yieldToken = _yieldToken;
        __BoringOwnable_init();
    }

    // solhint-disable no-empty-blocks
    receive() external payable {}

    /*///////////////////////////////////////////////////////////////
                    DEPOSIT/REDEEM USING BASE TOKENS
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev See {IStandardizedYield-deposit}
     */
    function deposit(
        address receiver,
        address tokenIn,
        uint256 amountTokenToDeposit,
        uint256 minSharesOut
    ) external payable nonReentrant returns (uint256 amountSharesOut) {
        if (!isValidTokenIn(tokenIn)) revert Errors.SYInvalidTokenIn(tokenIn);
        if (amountTokenToDeposit == 0) revert Errors.SYZeroDeposit();

        _transferIn(tokenIn, msg.sender, amountTokenToDeposit);

        amountSharesOut = _deposit(tokenIn, amountTokenToDeposit);
        if (amountSharesOut < minSharesOut) revert Errors.SYInsufficientSharesOut(amountSharesOut, minSharesOut);

        _mint(receiver, amountSharesOut);
        emit Deposit(msg.sender, receiver, tokenIn, amountTokenToDeposit, amountSharesOut);
    }

    /**
     * @dev See {IStandardizedYield-redeem}
     */
    function redeem(
        address receiver,
        uint256 amountSharesToRedeem,
        address tokenOut,
        uint256 minTokenOut,
        bool burnFromInternalBalance
    ) external nonReentrant returns (uint256 amountTokenOut) {
        if (!isValidTokenOut(tokenOut)) revert Errors.SYInvalidTokenOut(tokenOut);
        if (amountSharesToRedeem == 0) revert Errors.SYZeroRedeem();

        if (burnFromInternalBalance) {
            _burn(address(this), amountSharesToRedeem);
        } else {
            _burn(msg.sender, amountSharesToRedeem);
        }

        amountTokenOut = _redeem(receiver, tokenOut, amountSharesToRedeem);
        if (amountTokenOut < minTokenOut) revert Errors.SYInsufficientTokenOut(amountTokenOut, minTokenOut);
        emit Redeem(msg.sender, receiver, tokenOut, amountSharesToRedeem, amountTokenOut);
    }

    /**
     * @notice mint shares based on the deposited base tokens
     * @param tokenIn base token address used to mint shares
     * @param amountDeposited amount of base tokens deposited
     * @return amountSharesOut amount of shares minted
     */
    function _deposit(address tokenIn, uint256 amountDeposited) internal virtual returns (uint256 amountSharesOut);

    /**
     * @notice redeems base tokens based on amount of shares to be burned
     * @param tokenOut address of the base token to be redeemed
     * @param amountSharesToRedeem amount of shares to be burned
     * @return amountTokenOut amount of base tokens redeemed
     */
    function _redeem(
        address receiver,
        address tokenOut,
        uint256 amountSharesToRedeem
    ) internal virtual returns (uint256 amountTokenOut);

    /*///////////////////////////////////////////////////////////////
                               EXCHANGE-RATE
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev See {IStandardizedYield-exchangeRate}
     */
    function exchangeRate() external view virtual override returns (uint256 res);

    /*///////////////////////////////////////////////////////////////
                               REWARDS-RELATED
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev See {IStandardizedYield-claimRewards}
     */
    function claimRewards(address /*user*/) external virtual override returns (uint256[] memory rewardAmounts) {
        rewardAmounts = new uint256[](0);
    }

    /**
     * @dev See {IStandardizedYield-getRewardTokens}
     */
    function getRewardTokens() external view virtual override returns (address[] memory rewardTokens) {
        rewardTokens = new address[](0);
    }

    /**
     * @dev See {IStandardizedYield-accruedRewards}
     */
    function accruedRewards(address /*user*/) external view virtual override returns (uint256[] memory rewardAmounts) {
        rewardAmounts = new uint256[](0);
    }

    function rewardIndexesCurrent() external virtual override returns (uint256[] memory indexes) {
        indexes = new uint256[](0);
    }

    function rewardIndexesStored() external view virtual override returns (uint256[] memory indexes) {
        indexes = new uint256[](0);
    }

    /*///////////////////////////////////////////////////////////////
                MISC METADATA FUNCTIONS
    //////////////////////////////////////////////////////////////*/

    function previewDeposit(
        address tokenIn,
        uint256 amountTokenToDeposit
    ) external view virtual returns (uint256 amountSharesOut) {
        if (!isValidTokenIn(tokenIn)) revert Errors.SYInvalidTokenIn(tokenIn);
        return _previewDeposit(tokenIn, amountTokenToDeposit);
    }

    function previewRedeem(
        address tokenOut,
        uint256 amountSharesToRedeem
    ) external view virtual returns (uint256 amountTokenOut) {
        if (!isValidTokenOut(tokenOut)) revert Errors.SYInvalidTokenOut(tokenOut);
        return _previewRedeem(tokenOut, amountSharesToRedeem);
    }

    function pause() external onlyOwner {
        _pause();
    }

    function unpause() external onlyOwner {
        _unpause();
    }

    function _beforeTokenTransfer(address, address, uint256) internal virtual override whenNotPaused {}

    function _previewDeposit(
        address tokenIn,
        uint256 amountTokenToDeposit
    ) internal view virtual returns (uint256 amountSharesOut);

    function _previewRedeem(
        address tokenOut,
        uint256 amountSharesToRedeem
    ) internal view virtual returns (uint256 amountTokenOut);

    function getTokensIn() public view virtual returns (address[] memory res);

    function getTokensOut() public view virtual returns (address[] memory res);

    function isValidTokenIn(address token) public view virtual returns (bool);

    function isValidTokenOut(address token) public view virtual returns (bool);
}

// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;

import "../RewardManager/RewardManager.sol";
import "./SYBase.sol";

/// NOTE: yieldToken MUST NEVER BE a rewardToken, else the rewardManager will behave erroneously
abstract contract SYBaseWithRewards is SYBase, RewardManager {
    using PMath for uint256;
    using ArrayLib for address[];

    constructor(
        string memory _name,
        string memory _symbol,
        address _yieldToken
    )
        SYBase(_name, _symbol, _yieldToken) // solhint-disable-next-line no-empty-blocks
    {}

    /*///////////////////////////////////////////////////////////////
                               REWARDS-RELATED
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev See {IStandardizedYield-claimRewards}
     */
    function claimRewards(
        address user
    ) external virtual override nonReentrant whenNotPaused returns (uint256[] memory rewardAmounts) {
        _updateAndDistributeRewards(user);
        rewardAmounts = _doTransferOutRewards(user, user);

        emit ClaimRewards(user, _getRewardTokens(), rewardAmounts);
    }

    /**
     * @dev See {IStandardizedYield-getRewardTokens}
     */
    function getRewardTokens() external view virtual override returns (address[] memory rewardTokens) {
        rewardTokens = _getRewardTokens();
    }

    /**
     * @dev See {IStandardizedYield-accruedRewards}
     */
    function accruedRewards(address user) external view virtual override returns (uint256[] memory rewardAmounts) {
        address[] memory rewardTokens = _getRewardTokens();
        rewardAmounts = new uint256[](rewardTokens.length);
        for (uint256 i = 0; i < rewardTokens.length; ) {
            rewardAmounts[i] = userReward[rewardTokens[i]][user].accrued;
            unchecked {
                i++;
            }
        }
    }

    function rewardIndexesCurrent() external override nonReentrant whenNotPaused returns (uint256[] memory indexes) {
        (, indexes) = _updateRewardIndex();
    }

    function rewardIndexesStored() public view virtual override returns (uint256[] memory indexes) {
        address[] memory rewardTokens = _getRewardTokens();
        indexes = new uint256[](rewardTokens.length);
        for (uint256 i = 0; i < rewardTokens.length; ) {
            indexes[i] = rewardState[rewardTokens[i]].index;
            unchecked {
                i++;
            }
        }
    }

    /**
     * @notice returns the total number of reward shares
     * @dev this is simply the total supply of shares, as rewards shares are equivalent to SY shares
     */
    function _rewardSharesTotal() internal view virtual override returns (uint256) {
        return totalSupply();
    }

    /**
     * @notice returns the reward shares of (`user`)
     * @dev this is simply the SY balance of (`user`), as rewards shares are equivalent to SY shares
     */
    function _rewardSharesUser(address user) internal view virtual override returns (uint256) {
        return balanceOf(user);
    }

    /*///////////////////////////////////////////////////////////////
                            TRANSFER HOOKS
    //////////////////////////////////////////////////////////////*/
    function _beforeTokenTransfer(address from, address to, uint256) internal virtual override whenNotPaused {
        _updateAndDistributeRewardsForTwo(from, to);
    }
}