// File: lib/chainlink/contracts/src/v0.8/interfaces/AggregatorInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface AggregatorInterface {
  function latestAnswer() external view returns (int256);

  function latestTimestamp() external view returns (uint256);

  function latestRound() external view returns (uint256);

  function getAnswer(uint256 roundId) external view returns (int256);

  function getTimestamp(uint256 roundId) external view returns (uint256);

  event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);

  event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
}

// File: lib/chainlink/contracts/src/v0.8/interfaces/AggregatorV2V3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./AggregatorInterface.sol";
import "./AggregatorV3Interface.sol";

interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface {}

// File: lib/chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface AggregatorV3Interface {
  function decimals() external view returns (uint8);

  function description() external view returns (string memory);

  function version() external view returns (uint256);

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

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

// File: lib/chainlink/contracts/src/v0.8/interfaces/AutomationCompatibleInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface AutomationCompatibleInterface {
  /**
   * @notice method that is simulated by the keepers to see if any work actually
   * needs to be performed. This method does does not actually need to be
   * executable, and since it is only ever simulated it can consume lots of gas.
   * @dev To ensure that it is never called, you may want to add the
   * cannotExecute modifier from KeeperBase to your implementation of this
   * method.
   * @param checkData specified in the upkeep registration so it is always the
   * same for a registered upkeep. This can easily be broken down into specific
   * arguments using `abi.decode`, so multiple upkeeps can be registered on the
   * same contract and easily differentiated by the contract.
   * @return upkeepNeeded boolean to indicate whether the keeper should call
   * performUpkeep or not.
   * @return performData bytes that the keeper should call performUpkeep with, if
   * upkeep is needed. If you would like to encode data to decode later, try
   * `abi.encode`.
   */
  function checkUpkeep(bytes calldata checkData) external returns (bool upkeepNeeded, bytes memory performData);

  /**
   * @notice method that is actually executed by the keepers, via the registry.
   * The data returned by the checkUpkeep simulation will be passed into
   * this method to actually be executed.
   * @dev The input to this method should not be trusted, and the caller of the
   * method should not even be restricted to any single registry. Anyone should
   * be able call it, and the input should be validated, there is no guarantee
   * that the data passed in is the performData returned from checkUpkeep. This
   * could happen due to malicious keepers, racing keepers, or simply a state
   * change while the performUpkeep transaction is waiting for confirmation.
   * Always validate the data passed in.
   * @param performData is the data which was passed back from the checkData
   * simulation. If it is encoded, it can easily be decoded into other types by
   * calling `abi.decode`. This data should not be trusted, and should be
   * validated against the contract's current state.
   */
  function performUpkeep(bytes calldata performData) external;
}

// File: lib/openzeppelin-contracts/contracts/access/Ownable.sol



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: lib/openzeppelin-contracts/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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
     * ====
     *
     * [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/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (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);
        }
    }
}

// File: lib/openzeppelin-contracts/contracts/utils/Context.sol



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

pragma solidity ^0.8.0;

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

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

// File: lib/openzeppelin-contracts/contracts/utils/math/SafeCast.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/math/SafeCast.sol)
// This file was procedurally generated from scripts/generate/templates/SafeCast.js.

pragma solidity ^0.8.0;

/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Returns the downcasted uint248 from uint256, reverting on
     * overflow (when the input is greater than largest uint248).
     *
     * Counterpart to Solidity's `uint248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toUint248(uint256 value) internal pure returns (uint248) {
        require(value <= type(uint248).max, "SafeCast: value doesn't fit in 248 bits");
        return uint248(value);
    }

    /**
     * @dev Returns the downcasted uint240 from uint256, reverting on
     * overflow (when the input is greater than largest uint240).
     *
     * Counterpart to Solidity's `uint240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toUint240(uint256 value) internal pure returns (uint240) {
        require(value <= type(uint240).max, "SafeCast: value doesn't fit in 240 bits");
        return uint240(value);
    }

    /**
     * @dev Returns the downcasted uint232 from uint256, reverting on
     * overflow (when the input is greater than largest uint232).
     *
     * Counterpart to Solidity's `uint232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toUint232(uint256 value) internal pure returns (uint232) {
        require(value <= type(uint232).max, "SafeCast: value doesn't fit in 232 bits");
        return uint232(value);
    }

    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.2._
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
        return uint224(value);
    }

    /**
     * @dev Returns the downcasted uint216 from uint256, reverting on
     * overflow (when the input is greater than largest uint216).
     *
     * Counterpart to Solidity's `uint216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toUint216(uint256 value) internal pure returns (uint216) {
        require(value <= type(uint216).max, "SafeCast: value doesn't fit in 216 bits");
        return uint216(value);
    }

    /**
     * @dev Returns the downcasted uint208 from uint256, reverting on
     * overflow (when the input is greater than largest uint208).
     *
     * Counterpart to Solidity's `uint208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toUint208(uint256 value) internal pure returns (uint208) {
        require(value <= type(uint208).max, "SafeCast: value doesn't fit in 208 bits");
        return uint208(value);
    }

    /**
     * @dev Returns the downcasted uint200 from uint256, reverting on
     * overflow (when the input is greater than largest uint200).
     *
     * Counterpart to Solidity's `uint200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toUint200(uint256 value) internal pure returns (uint200) {
        require(value <= type(uint200).max, "SafeCast: value doesn't fit in 200 bits");
        return uint200(value);
    }

    /**
     * @dev Returns the downcasted uint192 from uint256, reverting on
     * overflow (when the input is greater than largest uint192).
     *
     * Counterpart to Solidity's `uint192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toUint192(uint256 value) internal pure returns (uint192) {
        require(value <= type(uint192).max, "SafeCast: value doesn't fit in 192 bits");
        return uint192(value);
    }

    /**
     * @dev Returns the downcasted uint184 from uint256, reverting on
     * overflow (when the input is greater than largest uint184).
     *
     * Counterpart to Solidity's `uint184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toUint184(uint256 value) internal pure returns (uint184) {
        require(value <= type(uint184).max, "SafeCast: value doesn't fit in 184 bits");
        return uint184(value);
    }

    /**
     * @dev Returns the downcasted uint176 from uint256, reverting on
     * overflow (when the input is greater than largest uint176).
     *
     * Counterpart to Solidity's `uint176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toUint176(uint256 value) internal pure returns (uint176) {
        require(value <= type(uint176).max, "SafeCast: value doesn't fit in 176 bits");
        return uint176(value);
    }

    /**
     * @dev Returns the downcasted uint168 from uint256, reverting on
     * overflow (when the input is greater than largest uint168).
     *
     * Counterpart to Solidity's `uint168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toUint168(uint256 value) internal pure returns (uint168) {
        require(value <= type(uint168).max, "SafeCast: value doesn't fit in 168 bits");
        return uint168(value);
    }

    /**
     * @dev Returns the downcasted uint160 from uint256, reverting on
     * overflow (when the input is greater than largest uint160).
     *
     * Counterpart to Solidity's `uint160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toUint160(uint256 value) internal pure returns (uint160) {
        require(value <= type(uint160).max, "SafeCast: value doesn't fit in 160 bits");
        return uint160(value);
    }

    /**
     * @dev Returns the downcasted uint152 from uint256, reverting on
     * overflow (when the input is greater than largest uint152).
     *
     * Counterpart to Solidity's `uint152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toUint152(uint256 value) internal pure returns (uint152) {
        require(value <= type(uint152).max, "SafeCast: value doesn't fit in 152 bits");
        return uint152(value);
    }

    /**
     * @dev Returns the downcasted uint144 from uint256, reverting on
     * overflow (when the input is greater than largest uint144).
     *
     * Counterpart to Solidity's `uint144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toUint144(uint256 value) internal pure returns (uint144) {
        require(value <= type(uint144).max, "SafeCast: value doesn't fit in 144 bits");
        return uint144(value);
    }

    /**
     * @dev Returns the downcasted uint136 from uint256, reverting on
     * overflow (when the input is greater than largest uint136).
     *
     * Counterpart to Solidity's `uint136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toUint136(uint256 value) internal pure returns (uint136) {
        require(value <= type(uint136).max, "SafeCast: value doesn't fit in 136 bits");
        return uint136(value);
    }

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v2.5._
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint120 from uint256, reverting on
     * overflow (when the input is greater than largest uint120).
     *
     * Counterpart to Solidity's `uint120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toUint120(uint256 value) internal pure returns (uint120) {
        require(value <= type(uint120).max, "SafeCast: value doesn't fit in 120 bits");
        return uint120(value);
    }

    /**
     * @dev Returns the downcasted uint112 from uint256, reverting on
     * overflow (when the input is greater than largest uint112).
     *
     * Counterpart to Solidity's `uint112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toUint112(uint256 value) internal pure returns (uint112) {
        require(value <= type(uint112).max, "SafeCast: value doesn't fit in 112 bits");
        return uint112(value);
    }

    /**
     * @dev Returns the downcasted uint104 from uint256, reverting on
     * overflow (when the input is greater than largest uint104).
     *
     * Counterpart to Solidity's `uint104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toUint104(uint256 value) internal pure returns (uint104) {
        require(value <= type(uint104).max, "SafeCast: value doesn't fit in 104 bits");
        return uint104(value);
    }

    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.2._
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
        return uint96(value);
    }

    /**
     * @dev Returns the downcasted uint88 from uint256, reverting on
     * overflow (when the input is greater than largest uint88).
     *
     * Counterpart to Solidity's `uint88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toUint88(uint256 value) internal pure returns (uint88) {
        require(value <= type(uint88).max, "SafeCast: value doesn't fit in 88 bits");
        return uint88(value);
    }

    /**
     * @dev Returns the downcasted uint80 from uint256, reverting on
     * overflow (when the input is greater than largest uint80).
     *
     * Counterpart to Solidity's `uint80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toUint80(uint256 value) internal pure returns (uint80) {
        require(value <= type(uint80).max, "SafeCast: value doesn't fit in 80 bits");
        return uint80(value);
    }

    /**
     * @dev Returns the downcasted uint72 from uint256, reverting on
     * overflow (when the input is greater than largest uint72).
     *
     * Counterpart to Solidity's `uint72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toUint72(uint256 value) internal pure returns (uint72) {
        require(value <= type(uint72).max, "SafeCast: value doesn't fit in 72 bits");
        return uint72(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v2.5._
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint56 from uint256, reverting on
     * overflow (when the input is greater than largest uint56).
     *
     * Counterpart to Solidity's `uint56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toUint56(uint256 value) internal pure returns (uint56) {
        require(value <= type(uint56).max, "SafeCast: value doesn't fit in 56 bits");
        return uint56(value);
    }

    /**
     * @dev Returns the downcasted uint48 from uint256, reverting on
     * overflow (when the input is greater than largest uint48).
     *
     * Counterpart to Solidity's `uint48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toUint48(uint256 value) internal pure returns (uint48) {
        require(value <= type(uint48).max, "SafeCast: value doesn't fit in 48 bits");
        return uint48(value);
    }

    /**
     * @dev Returns the downcasted uint40 from uint256, reverting on
     * overflow (when the input is greater than largest uint40).
     *
     * Counterpart to Solidity's `uint40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toUint40(uint256 value) internal pure returns (uint40) {
        require(value <= type(uint40).max, "SafeCast: value doesn't fit in 40 bits");
        return uint40(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v2.5._
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint24 from uint256, reverting on
     * overflow (when the input is greater than largest uint24).
     *
     * Counterpart to Solidity's `uint24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toUint24(uint256 value) internal pure returns (uint24) {
        require(value <= type(uint24).max, "SafeCast: value doesn't fit in 24 bits");
        return uint24(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v2.5._
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v2.5._
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     *
     * _Available since v3.0._
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int248 from int256, reverting on
     * overflow (when the input is less than smallest int248 or
     * greater than largest int248).
     *
     * Counterpart to Solidity's `int248` operator.
     *
     * Requirements:
     *
     * - input must fit into 248 bits
     *
     * _Available since v4.7._
     */
    function toInt248(int256 value) internal pure returns (int248 downcasted) {
        downcasted = int248(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 248 bits");
    }

    /**
     * @dev Returns the downcasted int240 from int256, reverting on
     * overflow (when the input is less than smallest int240 or
     * greater than largest int240).
     *
     * Counterpart to Solidity's `int240` operator.
     *
     * Requirements:
     *
     * - input must fit into 240 bits
     *
     * _Available since v4.7._
     */
    function toInt240(int256 value) internal pure returns (int240 downcasted) {
        downcasted = int240(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 240 bits");
    }

    /**
     * @dev Returns the downcasted int232 from int256, reverting on
     * overflow (when the input is less than smallest int232 or
     * greater than largest int232).
     *
     * Counterpart to Solidity's `int232` operator.
     *
     * Requirements:
     *
     * - input must fit into 232 bits
     *
     * _Available since v4.7._
     */
    function toInt232(int256 value) internal pure returns (int232 downcasted) {
        downcasted = int232(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 232 bits");
    }

    /**
     * @dev Returns the downcasted int224 from int256, reverting on
     * overflow (when the input is less than smallest int224 or
     * greater than largest int224).
     *
     * Counterpart to Solidity's `int224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     *
     * _Available since v4.7._
     */
    function toInt224(int256 value) internal pure returns (int224 downcasted) {
        downcasted = int224(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 224 bits");
    }

    /**
     * @dev Returns the downcasted int216 from int256, reverting on
     * overflow (when the input is less than smallest int216 or
     * greater than largest int216).
     *
     * Counterpart to Solidity's `int216` operator.
     *
     * Requirements:
     *
     * - input must fit into 216 bits
     *
     * _Available since v4.7._
     */
    function toInt216(int256 value) internal pure returns (int216 downcasted) {
        downcasted = int216(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 216 bits");
    }

    /**
     * @dev Returns the downcasted int208 from int256, reverting on
     * overflow (when the input is less than smallest int208 or
     * greater than largest int208).
     *
     * Counterpart to Solidity's `int208` operator.
     *
     * Requirements:
     *
     * - input must fit into 208 bits
     *
     * _Available since v4.7._
     */
    function toInt208(int256 value) internal pure returns (int208 downcasted) {
        downcasted = int208(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 208 bits");
    }

    /**
     * @dev Returns the downcasted int200 from int256, reverting on
     * overflow (when the input is less than smallest int200 or
     * greater than largest int200).
     *
     * Counterpart to Solidity's `int200` operator.
     *
     * Requirements:
     *
     * - input must fit into 200 bits
     *
     * _Available since v4.7._
     */
    function toInt200(int256 value) internal pure returns (int200 downcasted) {
        downcasted = int200(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 200 bits");
    }

    /**
     * @dev Returns the downcasted int192 from int256, reverting on
     * overflow (when the input is less than smallest int192 or
     * greater than largest int192).
     *
     * Counterpart to Solidity's `int192` operator.
     *
     * Requirements:
     *
     * - input must fit into 192 bits
     *
     * _Available since v4.7._
     */
    function toInt192(int256 value) internal pure returns (int192 downcasted) {
        downcasted = int192(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 192 bits");
    }

    /**
     * @dev Returns the downcasted int184 from int256, reverting on
     * overflow (when the input is less than smallest int184 or
     * greater than largest int184).
     *
     * Counterpart to Solidity's `int184` operator.
     *
     * Requirements:
     *
     * - input must fit into 184 bits
     *
     * _Available since v4.7._
     */
    function toInt184(int256 value) internal pure returns (int184 downcasted) {
        downcasted = int184(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 184 bits");
    }

    /**
     * @dev Returns the downcasted int176 from int256, reverting on
     * overflow (when the input is less than smallest int176 or
     * greater than largest int176).
     *
     * Counterpart to Solidity's `int176` operator.
     *
     * Requirements:
     *
     * - input must fit into 176 bits
     *
     * _Available since v4.7._
     */
    function toInt176(int256 value) internal pure returns (int176 downcasted) {
        downcasted = int176(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 176 bits");
    }

    /**
     * @dev Returns the downcasted int168 from int256, reverting on
     * overflow (when the input is less than smallest int168 or
     * greater than largest int168).
     *
     * Counterpart to Solidity's `int168` operator.
     *
     * Requirements:
     *
     * - input must fit into 168 bits
     *
     * _Available since v4.7._
     */
    function toInt168(int256 value) internal pure returns (int168 downcasted) {
        downcasted = int168(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 168 bits");
    }

    /**
     * @dev Returns the downcasted int160 from int256, reverting on
     * overflow (when the input is less than smallest int160 or
     * greater than largest int160).
     *
     * Counterpart to Solidity's `int160` operator.
     *
     * Requirements:
     *
     * - input must fit into 160 bits
     *
     * _Available since v4.7._
     */
    function toInt160(int256 value) internal pure returns (int160 downcasted) {
        downcasted = int160(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 160 bits");
    }

    /**
     * @dev Returns the downcasted int152 from int256, reverting on
     * overflow (when the input is less than smallest int152 or
     * greater than largest int152).
     *
     * Counterpart to Solidity's `int152` operator.
     *
     * Requirements:
     *
     * - input must fit into 152 bits
     *
     * _Available since v4.7._
     */
    function toInt152(int256 value) internal pure returns (int152 downcasted) {
        downcasted = int152(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 152 bits");
    }

    /**
     * @dev Returns the downcasted int144 from int256, reverting on
     * overflow (when the input is less than smallest int144 or
     * greater than largest int144).
     *
     * Counterpart to Solidity's `int144` operator.
     *
     * Requirements:
     *
     * - input must fit into 144 bits
     *
     * _Available since v4.7._
     */
    function toInt144(int256 value) internal pure returns (int144 downcasted) {
        downcasted = int144(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 144 bits");
    }

    /**
     * @dev Returns the downcasted int136 from int256, reverting on
     * overflow (when the input is less than smallest int136 or
     * greater than largest int136).
     *
     * Counterpart to Solidity's `int136` operator.
     *
     * Requirements:
     *
     * - input must fit into 136 bits
     *
     * _Available since v4.7._
     */
    function toInt136(int256 value) internal pure returns (int136 downcasted) {
        downcasted = int136(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 136 bits");
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128 downcasted) {
        downcasted = int128(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 128 bits");
    }

    /**
     * @dev Returns the downcasted int120 from int256, reverting on
     * overflow (when the input is less than smallest int120 or
     * greater than largest int120).
     *
     * Counterpart to Solidity's `int120` operator.
     *
     * Requirements:
     *
     * - input must fit into 120 bits
     *
     * _Available since v4.7._
     */
    function toInt120(int256 value) internal pure returns (int120 downcasted) {
        downcasted = int120(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 120 bits");
    }

    /**
     * @dev Returns the downcasted int112 from int256, reverting on
     * overflow (when the input is less than smallest int112 or
     * greater than largest int112).
     *
     * Counterpart to Solidity's `int112` operator.
     *
     * Requirements:
     *
     * - input must fit into 112 bits
     *
     * _Available since v4.7._
     */
    function toInt112(int256 value) internal pure returns (int112 downcasted) {
        downcasted = int112(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 112 bits");
    }

    /**
     * @dev Returns the downcasted int104 from int256, reverting on
     * overflow (when the input is less than smallest int104 or
     * greater than largest int104).
     *
     * Counterpart to Solidity's `int104` operator.
     *
     * Requirements:
     *
     * - input must fit into 104 bits
     *
     * _Available since v4.7._
     */
    function toInt104(int256 value) internal pure returns (int104 downcasted) {
        downcasted = int104(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 104 bits");
    }

    /**
     * @dev Returns the downcasted int96 from int256, reverting on
     * overflow (when the input is less than smallest int96 or
     * greater than largest int96).
     *
     * Counterpart to Solidity's `int96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     *
     * _Available since v4.7._
     */
    function toInt96(int256 value) internal pure returns (int96 downcasted) {
        downcasted = int96(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 96 bits");
    }

    /**
     * @dev Returns the downcasted int88 from int256, reverting on
     * overflow (when the input is less than smallest int88 or
     * greater than largest int88).
     *
     * Counterpart to Solidity's `int88` operator.
     *
     * Requirements:
     *
     * - input must fit into 88 bits
     *
     * _Available since v4.7._
     */
    function toInt88(int256 value) internal pure returns (int88 downcasted) {
        downcasted = int88(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 88 bits");
    }

    /**
     * @dev Returns the downcasted int80 from int256, reverting on
     * overflow (when the input is less than smallest int80 or
     * greater than largest int80).
     *
     * Counterpart to Solidity's `int80` operator.
     *
     * Requirements:
     *
     * - input must fit into 80 bits
     *
     * _Available since v4.7._
     */
    function toInt80(int256 value) internal pure returns (int80 downcasted) {
        downcasted = int80(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 80 bits");
    }

    /**
     * @dev Returns the downcasted int72 from int256, reverting on
     * overflow (when the input is less than smallest int72 or
     * greater than largest int72).
     *
     * Counterpart to Solidity's `int72` operator.
     *
     * Requirements:
     *
     * - input must fit into 72 bits
     *
     * _Available since v4.7._
     */
    function toInt72(int256 value) internal pure returns (int72 downcasted) {
        downcasted = int72(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 72 bits");
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64 downcasted) {
        downcasted = int64(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 64 bits");
    }

    /**
     * @dev Returns the downcasted int56 from int256, reverting on
     * overflow (when the input is less than smallest int56 or
     * greater than largest int56).
     *
     * Counterpart to Solidity's `int56` operator.
     *
     * Requirements:
     *
     * - input must fit into 56 bits
     *
     * _Available since v4.7._
     */
    function toInt56(int256 value) internal pure returns (int56 downcasted) {
        downcasted = int56(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 56 bits");
    }

    /**
     * @dev Returns the downcasted int48 from int256, reverting on
     * overflow (when the input is less than smallest int48 or
     * greater than largest int48).
     *
     * Counterpart to Solidity's `int48` operator.
     *
     * Requirements:
     *
     * - input must fit into 48 bits
     *
     * _Available since v4.7._
     */
    function toInt48(int256 value) internal pure returns (int48 downcasted) {
        downcasted = int48(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 48 bits");
    }

    /**
     * @dev Returns the downcasted int40 from int256, reverting on
     * overflow (when the input is less than smallest int40 or
     * greater than largest int40).
     *
     * Counterpart to Solidity's `int40` operator.
     *
     * Requirements:
     *
     * - input must fit into 40 bits
     *
     * _Available since v4.7._
     */
    function toInt40(int256 value) internal pure returns (int40 downcasted) {
        downcasted = int40(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 40 bits");
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32 downcasted) {
        downcasted = int32(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 32 bits");
    }

    /**
     * @dev Returns the downcasted int24 from int256, reverting on
     * overflow (when the input is less than smallest int24 or
     * greater than largest int24).
     *
     * Counterpart to Solidity's `int24` operator.
     *
     * Requirements:
     *
     * - input must fit into 24 bits
     *
     * _Available since v4.7._
     */
    function toInt24(int256 value) internal pure returns (int24 downcasted) {
        downcasted = int24(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 24 bits");
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16 downcasted) {
        downcasted = int16(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 16 bits");
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8 downcasted) {
        downcasted = int8(value);
        require(downcasted == value, "SafeCast: value doesn't fit in 8 bits");
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     *
     * _Available since v3.0._
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}

// File: src/base/ERC20.sol



// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /*//////////////////////////////////////////////////////////////
                            METADATA STORAGE
    //////////////////////////////////////////////////////////////*/

    string public name;

    string public symbol;

    uint8 public decimals;

    /*//////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;

    mapping(address => mapping(address => uint256)) public allowance;

    /*//////////////////////////////////////////////////////////////
                            EIP-2612 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 internal INITIAL_CHAIN_ID;

    bytes32 internal INITIAL_DOMAIN_SEPARATOR;

    mapping(address => uint256) public nonces;

    /*//////////////////////////////////////////////////////////////
                               CONSTRUCTOR
    //////////////////////////////////////////////////////////////*/

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        INITIAL_CHAIN_ID = block.chainid;
        INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
    }

    /*//////////////////////////////////////////////////////////////
                               ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/

    function approve(address spender, uint256 amount) public virtual returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transfer(address to, uint256 amount) public virtual returns (bool) {
        balanceOf[msg.sender] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(msg.sender, to, amount);

        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.

        if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

        return true;
    }

    /*//////////////////////////////////////////////////////////////
                             EIP-2612 LOGIC
    //////////////////////////////////////////////////////////////*/

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");

        // Unchecked because the only math done is incrementing
        // the owner's nonce which cannot realistically overflow.
        unchecked {
            address recoveredAddress = ecrecover(
                keccak256(
                    abi.encodePacked(
                        "\x19\x01",
                        DOMAIN_SEPARATOR(),
                        keccak256(
                            abi.encode(
                                keccak256(
                                    "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
                                ),
                                owner,
                                spender,
                                value,
                                nonces[owner]++,
                                deadline
                            )
                        )
                    )
                ),
                v,
                r,
                s
            );

            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");

            allowance[recoveredAddress][spender] = value;
        }

        emit Approval(owner, spender, value);
    }

    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
        return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
    }

    function computeDomainSeparator() internal view virtual returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                    keccak256(bytes(name)),
                    keccak256("1"),
                    block.chainid,
                    address(this)
                )
            );
    }

    /*//////////////////////////////////////////////////////////////
                        INTERNAL MINT/BURN LOGIC
    //////////////////////////////////////////////////////////////*/

    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(address(0), to, amount);
    }

    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;

        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }

        emit Transfer(from, address(0), amount);
    }
}

// File: src/base/ERC4626.sol



// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

import { ERC20 } from "src/base/ERC20.sol";
import { SafeTransferLib } from "src/base/SafeTransferLib.sol";
import { Math } from "src/utils/Math.sol";

/// @notice Minimal ERC4626 tokenized Vault implementation.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/mixins/ERC4626.sol)
abstract contract ERC4626 is ERC20 {
    using SafeTransferLib for ERC20;
    using Math for uint256;

    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Deposit(address indexed caller, address indexed owner, uint256 assets, uint256 shares);

    event Withdraw(
        address indexed caller,
        address indexed receiver,
        address indexed owner,
        uint256 assets,
        uint256 shares
    );

    /*//////////////////////////////////////////////////////////////
                               IMMUTABLES
    //////////////////////////////////////////////////////////////*/

    ERC20 public asset;

    constructor(
        ERC20 _asset,
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) ERC20(_name, _symbol, _decimals) {
        asset = _asset;
    }

    /*//////////////////////////////////////////////////////////////
                        DEPOSIT/WITHDRAWAL LOGIC
    //////////////////////////////////////////////////////////////*/

    function deposit(uint256 assets, address receiver) public virtual returns (uint256 shares) {
        // Check for rounding error since we round down in previewDeposit.
        require((shares = previewDeposit(assets)) != 0, "ZERO_SHARES");

        beforeDeposit(assets, shares, receiver);

        // Need to transfer before minting or ERC777s could reenter.
        asset.safeTransferFrom(msg.sender, address(this), assets);

        _mint(receiver, shares);

        emit Deposit(msg.sender, receiver, assets, shares);

        afterDeposit(assets, shares, receiver);
    }

    function mint(uint256 shares, address receiver) public virtual returns (uint256 assets) {
        assets = previewMint(shares); // No need to check for rounding error, previewMint rounds up.

        beforeDeposit(assets, shares, receiver);

        // Need to transfer before minting or ERC777s could reenter.
        asset.safeTransferFrom(msg.sender, address(this), assets);

        _mint(receiver, shares);

        emit Deposit(msg.sender, receiver, assets, shares);

        afterDeposit(assets, shares, receiver);
    }

    function withdraw(
        uint256 assets,
        address receiver,
        address owner
    ) public virtual returns (uint256 shares) {
        shares = previewWithdraw(assets); // No need to check for rounding error, previewWithdraw rounds up.

        if (msg.sender != owner) {
            uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.

            if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;
        }

        beforeWithdraw(assets, shares, receiver, owner);

        _burn(owner, shares);

        emit Withdraw(msg.sender, receiver, owner, assets, shares);

        asset.safeTransfer(receiver, assets);

        afterWithdraw(assets, shares, receiver, owner);
    }

    function redeem(
        uint256 shares,
        address receiver,
        address owner
    ) public virtual returns (uint256 assets) {
        if (msg.sender != owner) {
            uint256 allowed = allowance[owner][msg.sender]; // Saves gas for limited approvals.

            if (allowed != type(uint256).max) allowance[owner][msg.sender] = allowed - shares;
        }

        // Check for rounding error since we round down in previewRedeem.
        require((assets = previewRedeem(shares)) != 0, "ZERO_ASSETS");

        beforeWithdraw(assets, shares, receiver, owner);

        _burn(owner, shares);

        emit Withdraw(msg.sender, receiver, owner, assets, shares);

        asset.safeTransfer(receiver, assets);

        afterWithdraw(assets, shares, receiver, owner);
    }

    /*//////////////////////////////////////////////////////////////
                            ACCOUNTING LOGIC
    //////////////////////////////////////////////////////////////*/

    function totalAssets() public view virtual returns (uint256);

    function convertToShares(uint256 assets) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? assets : assets.mulDivDown(supply, totalAssets());
    }

    function convertToAssets(uint256 shares) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? shares : shares.mulDivDown(totalAssets(), supply);
    }

    function previewDeposit(uint256 assets) public view virtual returns (uint256) {
        return convertToShares(assets);
    }

    function previewMint(uint256 shares) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? shares : shares.mulDivUp(totalAssets(), supply);
    }

    function previewWithdraw(uint256 assets) public view virtual returns (uint256) {
        uint256 supply = totalSupply; // Saves an extra SLOAD if totalSupply is non-zero.

        return supply == 0 ? assets : assets.mulDivUp(supply, totalAssets());
    }

    function previewRedeem(uint256 shares) public view virtual returns (uint256) {
        return convertToAssets(shares);
    }

    /*//////////////////////////////////////////////////////////////
                     DEPOSIT/WITHDRAWAL LIMIT LOGIC
    //////////////////////////////////////////////////////////////*/

    function maxDeposit(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    function maxMint(address) public view virtual returns (uint256) {
        return type(uint256).max;
    }

    function maxWithdraw(address owner) public view virtual returns (uint256) {
        return convertToAssets(balanceOf[owner]);
    }

    function maxRedeem(address owner) public view virtual returns (uint256) {
        return balanceOf[owner];
    }

    /*//////////////////////////////////////////////////////////////
                          INTERNAL HOOKS LOGIC
    //////////////////////////////////////////////////////////////*/

    function beforeDeposit(
        uint256 assets,
        uint256 shares,
        address receiver
    ) internal virtual {}

    function afterDeposit(
        uint256 assets,
        uint256 shares,
        address receiver
    ) internal virtual {}

    function beforeWithdraw(
        uint256 assets,
        uint256 shares,
        address receiver,
        address owner
    ) internal virtual {}

    function afterWithdraw(
        uint256 assets,
        uint256 shares,
        address receiver,
        address owner
    ) internal virtual {}
}

// File: src/base/SafeTransferLib.sol



// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

import { ERC20 } from "src/base/ERC20.sol";

/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @dev Use with caution! Some functions in this library knowingly create dirty bits at the destination of the free memory pointer.
/// @dev Note that none of the functions in this library check that a token has code at all! That responsibility is delegated to the caller.
library SafeTransferLib {
    /*//////////////////////////////////////////////////////////////
                             ETH OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferETH(address to, uint256 amount) internal {
        bool success;

        assembly {
            // Transfer the ETH and store if it succeeded or not.
            success := call(gas(), to, amount, 0, 0, 0, 0)
        }

        require(success, "ETH_TRANSFER_FAILED");
    }

    /*//////////////////////////////////////////////////////////////
                            ERC20 OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferFrom(
        ERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bool success;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), from) // Append the "from" argument.
            mstore(add(freeMemoryPointer, 36), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 68), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 100 because the length of our calldata totals up like so: 4 + 32 * 3.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 100, 0, 32)
            )
        }

        require(success, "TRANSFER_FROM_FAILED");
    }

    function safeTransfer(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool success;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "TRANSFER_FAILED");
    }

    function safeApprove(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool success;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata into memory, beginning with the function selector.
            mstore(freeMemoryPointer, 0x095ea7b300000000000000000000000000000000000000000000000000000000)
            mstore(add(freeMemoryPointer, 4), to) // Append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Append the "amount" argument.

            success := and(
                // Set success to whether the call reverted, if not we check it either
                // returned exactly 1 (can't just be non-zero data), or had no return data.
                or(and(eq(mload(0), 1), gt(returndatasize(), 31)), iszero(returndatasize())),
                // We use 68 because the length of our calldata totals up like so: 4 + 32 * 2.
                // We use 0 and 32 to copy up to 32 bytes of return data into the scratch space.
                // Counterintuitively, this call must be positioned second to the or() call in the
                // surrounding and() call or else returndatasize() will be zero during the computation.
                call(gas(), token, 0, freeMemoryPointer, 68, 0, 32)
            )
        }

        require(success, "APPROVE_FAILED");
    }
}

// File: src/interfaces/external/IAaveToken.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.16;

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

interface IAaveToken {
    function UNDERLYING_ASSET_ADDRESS() external view returns (address);
}

// File: src/interfaces/external/IChainlinkAggregator.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.8.16;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV2V3Interface.sol";

interface IChainlinkAggregator is AggregatorV2V3Interface {
    function maxAnswer() external view returns (int192);

    function minAnswer() external view returns (int192);

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

// File: src/interfaces/external/ICurvePool.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.8.16;

interface ICurvePool {
    function coins(uint256 i) external view returns (address);

    function get_virtual_price() external view returns (uint256);

    function claim_admin_fees() external; // For USDT/WETH/WBTC

    function withdraw_admin_fees() external;

    function gamma() external view returns (uint256);

    function A() external view returns (uint256);

    function lp_price() external view returns (uint256);

    function price_oracle() external view returns (uint256);

    function price_oracle(uint256 i) external view returns (uint256);
}

// File: src/modules/price-router/PriceRouter.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.8.16;

import { ERC20, SafeTransferLib } from "src/base/ERC4626.sol";
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { AutomationCompatibleInterface } from "@chainlink/contracts/src/v0.8/interfaces/AutomationCompatibleInterface.sol";
import { IChainlinkAggregator } from "src/interfaces/external/IChainlinkAggregator.sol";
import { SafeCast } from "@openzeppelin/contracts/utils/math/SafeCast.sol";
import { Math } from "src/utils/Math.sol";
import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { ICurvePool } from "src/interfaces/external/ICurvePool.sol";
import { IAaveToken } from "src/interfaces/external/IAaveToken.sol";

/**
 * @title Sommelier Price Router
 * @notice Provides a universal interface allowing Sommelier contracts to retrieve secure pricing
 *         data from Chainlink.
 * @author crispymangoes, Brian Le
 */
contract PriceRouter is Ownable, AutomationCompatibleInterface {
    using SafeTransferLib for ERC20;
    using SafeCast for int256;
    using Math for uint256;
    using Address for address;

    event AddAsset(address indexed asset);

    // =========================================== ASSETS CONFIG ===========================================
    /**
     * @notice Bare minimum settings all derivatives support.
     * @param derivative the derivative used to price the asset
     * @param source the address used to price the asset
     */
    struct AssetSettings {
        uint8 derivative;
        address source;
    }

    /**
     * @notice Mapping between an asset to price and its `AssetSettings`.
     */
    mapping(ERC20 => AssetSettings) public getAssetSettings;

    // ======================================= ADAPTOR OPERATIONS =======================================

    /**
     * @notice Attempted to set a minimum price below the Chainlink minimum price (with buffer).
     * @param minPrice minimum price attempted to set
     * @param bufferedMinPrice minimum price that can be set including buffer
     */
    error PriceRouter__InvalidMinPrice(uint256 minPrice, uint256 bufferedMinPrice);

    /**
     * @notice Attempted to set a maximum price above the Chainlink maximum price (with buffer).
     * @param maxPrice maximum price attempted to set
     * @param bufferedMaxPrice maximum price that can be set including buffer
     */
    error PriceRouter__InvalidMaxPrice(uint256 maxPrice, uint256 bufferedMaxPrice);

    /**
     * @notice Attempted to add an invalid asset.
     * @param asset address of the invalid asset
     */
    error PriceRouter__InvalidAsset(address asset);

    /**
     * @notice Attempted to add an asset, but actual answer was outside range of expectedAnswer.
     */
    error PriceRouter__BadAnswer(uint256 answer, uint256 expectedAnswer);

    /**
     * @notice Attempted to perform an operation using an unkown derivative.
     */
    error PriceRouter__UnkownDerivative(uint8 unkownDerivative);

    /**
     * @notice Attempted to add an asset with invalid min/max prices.
     * @param min price
     * @param max price
     */
    error PriceRouter__MinPriceGreaterThanMaxPrice(uint256 min, uint256 max);

    /**
     * @notice The allowed deviation between the expected answer vs the actual answer.
     */
    uint256 public constant EXPECTED_ANSWER_DEVIATION = 0.02e18;

    /**
     * @notice Stores pricing information during calls.
     * @param asset the address of the asset
     * @param price the USD price of the asset
     * @dev If the price does not fit into a uint96, the asset is NOT added to the cache.
     */
    struct PriceCache {
        address asset;
        uint96 price;
    }

    /**
     * @notice The size of the price cache. A larger cache can hold more values,
     *         but incurs a larger gas cost overhead. A smaller cache has a
     *         smaller gas overhead but caches less prices.
     */
    uint8 private constant PRICE_CACHE_SIZE = 8;

    /**
     * @notice Allows owner to add assets to the price router.
     * @dev Performs a sanity check by comparing the price router computed price to
     * a user input `_expectedAnswer`.
     * @param _asset the asset to add to the pricing router
     * @param _settings the settings for `_asset`
     *        @dev The `derivative` value in settings MUST be non zero.
     * @param _storage arbitrary bytes data used to configure `_asset` pricing
     * @param _expectedAnswer the expected answer for the asset from  `_getPriceInUSD`
     */
    function addAsset(
        ERC20 _asset,
        AssetSettings memory _settings,
        bytes memory _storage,
        uint256 _expectedAnswer
    ) external onlyOwner {
        if (address(_asset) == address(0)) revert PriceRouter__InvalidAsset(address(_asset));
        // Zero is an invalid derivative.
        if (_settings.derivative == 0) revert PriceRouter__UnkownDerivative(_settings.derivative);

        // Call setup function for appropriate derivative.
        if (_settings.derivative == 1) {
            _setupPriceForChainlinkDerivative(_asset, _settings.source, _storage);
        } else if (_settings.derivative == 2) {
            _setupPriceForCurveDerivative(_asset, _settings.source, _storage);
        } else if (_settings.derivative == 3) {
            _setupPriceForCurveV2Derivative(_asset, _settings.source, _storage);
        } else if (_settings.derivative == 4) {
            _setupPriceForAaveDerivative(_asset, _settings.source, _storage);
        } else revert PriceRouter__UnkownDerivative(_settings.derivative);

        // Check `_getPriceInUSD` against `_expectedAnswer`.
        uint256 minAnswer = _expectedAnswer.mulWadDown((1e18 - EXPECTED_ANSWER_DEVIATION));
        uint256 maxAnswer = _expectedAnswer.mulWadDown((1e18 + EXPECTED_ANSWER_DEVIATION));
        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;
        getAssetSettings[_asset] = _settings;
        uint256 answer = _getPriceInUSD(_asset, _settings, cache);
        if (answer < minAnswer || answer > maxAnswer) revert PriceRouter__BadAnswer(answer, _expectedAnswer);

        emit AddAsset(address(_asset));
    }

    /**
     * @notice return bool indicating whether or not an asset has been set up.
     * @dev Since `addAsset` enforces the derivative is non zero, checking if the stored setting
     *      is nonzero is sufficient to see if the asset is set up.
     */
    function isSupported(ERC20 asset) external view returns (bool) {
        return getAssetSettings[asset].derivative > 0;
    }

    // ======================================= CHAINLINK AUTOMATION =======================================
    /**
     * @notice `checkUpkeep` is set up to allow for multiple derivatives to use Chainlink Automation.
     */
    function checkUpkeep(bytes calldata checkData) external view returns (bool upkeepNeeded, bytes memory performData) {
        (uint8 derivative, bytes memory derivativeCheckData) = abi.decode(checkData, (uint8, bytes));

        if (derivative == 2) {
            (upkeepNeeded, performData) = _checkVirtualPriceBound(derivativeCheckData);
        } else if (derivative == 3) {
            (upkeepNeeded, performData) = _checkVirtualPriceBound(derivativeCheckData);
        } else revert PriceRouter__UnkownDerivative(derivative);
    }

    /**
     * @notice `performUpkeep` is set up to allow for multiple derivatives to use Chainlink Automation.
     */
    function performUpkeep(bytes calldata performData) external {
        (uint8 derivative, bytes memory derivativePerformData) = abi.decode(performData, (uint8, bytes));

        if (derivative == 2) {
            _updateVirtualPriceBound(derivativePerformData);
        } else if (derivative == 3) {
            _updateVirtualPriceBound(derivativePerformData);
        } else revert PriceRouter__UnkownDerivative(derivative);
    }

    // ======================================= PRICING OPERATIONS =======================================

    /**
     * @notice Get `asset` price in USD.
     * @dev Returns price in USD with 8 decimals.
     */
    function getPriceInUSD(ERC20 asset) external view returns (uint256) {
        AssetSettings memory assetSettings = getAssetSettings[asset];
        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;
        return _getPriceInUSD(asset, assetSettings, cache);
    }

    /**
     * @notice Get the value of an asset in terms of another asset.
     * @param baseAsset address of the asset to get the price of in terms of the quote asset
     * @param amount amount of the base asset to price
     * @param quoteAsset address of the asset that the base asset is priced in terms of
     * @return value value of the amount of base assets specified in terms of the quote asset
     */
    function getValue(
        ERC20 baseAsset,
        uint256 amount,
        ERC20 quoteAsset
    ) external view returns (uint256 value) {
        AssetSettings memory baseSettings = getAssetSettings[baseAsset];
        AssetSettings memory quoteSettings = getAssetSettings[quoteAsset];
        if (baseSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(baseAsset));
        if (quoteSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(quoteAsset));
        PriceCache[PRICE_CACHE_SIZE] memory cache;
        uint256 priceBaseUSD = _getPriceInUSD(baseAsset, baseSettings, cache);
        uint256 priceQuoteUSD = _getPriceInUSD(quoteAsset, quoteSettings, cache);
        value = _getValueInQuote(priceBaseUSD, priceQuoteUSD, baseAsset.decimals(), quoteAsset.decimals(), amount);
    }

    /**
     * @notice Helper function that compares `_getValues` between input 0 and input 1.
     */
    function getValuesDelta(
        ERC20[] calldata baseAssets0,
        uint256[] calldata amounts0,
        ERC20[] calldata baseAssets1,
        uint256[] calldata amounts1,
        ERC20 quoteAsset
    ) external view returns (uint256) {
        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;

        uint256 value0 = _getValues(baseAssets0, amounts0, quoteAsset, cache);
        uint256 value1 = _getValues(baseAssets1, amounts1, quoteAsset, cache);
        return value0 - value1;
    }

    /**
     * @notice Helper function that determines the value of assets using `_getValues`.
     */
    function getValues(
        ERC20[] calldata baseAssets,
        uint256[] calldata amounts,
        ERC20 quoteAsset
    ) external view returns (uint256) {
        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;

        return _getValues(baseAssets, amounts, quoteAsset, cache);
    }

    /**
     * @notice Get the exchange rate between two assets.
     * @param baseAsset address of the asset to get the exchange rate of in terms of the quote asset
     * @param quoteAsset address of the asset that the base asset is exchanged for
     * @return exchangeRate rate of exchange between the base asset and the quote asset
     */
    function getExchangeRate(ERC20 baseAsset, ERC20 quoteAsset) public view returns (uint256 exchangeRate) {
        AssetSettings memory baseSettings = getAssetSettings[baseAsset];
        AssetSettings memory quoteSettings = getAssetSettings[quoteAsset];
        if (baseSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(baseAsset));
        if (quoteSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(quoteAsset));

        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;
        // Pass in zero for ethToUsd, since it has not been set yet.
        exchangeRate = _getExchangeRate(
            baseAsset,
            baseSettings,
            quoteAsset,
            quoteSettings,
            quoteAsset.decimals(),
            cache
        );
    }

    /**
     * @notice Get the exchange rates between multiple assets and another asset.
     * @param baseAssets addresses of the assets to get the exchange rates of in terms of the quote asset
     * @param quoteAsset address of the asset that the base assets are exchanged for
     * @return exchangeRates rate of exchange between the base assets and the quote asset
     */
    function getExchangeRates(ERC20[] memory baseAssets, ERC20 quoteAsset)
        external
        view
        returns (uint256[] memory exchangeRates)
    {
        uint8 quoteAssetDecimals = quoteAsset.decimals();
        AssetSettings memory quoteSettings = getAssetSettings[quoteAsset];
        if (quoteSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(quoteAsset));

        // Create an empty Price Cache.
        PriceCache[PRICE_CACHE_SIZE] memory cache;

        uint256 numOfAssets = baseAssets.length;
        exchangeRates = new uint256[](numOfAssets);
        for (uint256 i; i < numOfAssets; i++) {
            AssetSettings memory baseSettings = getAssetSettings[baseAssets[i]];
            if (baseSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(baseAssets[i]));
            exchangeRates[i] = _getExchangeRate(
                baseAssets[i],
                baseSettings,
                quoteAsset,
                quoteSettings,
                quoteAssetDecimals,
                cache
            );
        }
    }

    // =========================================== HELPER FUNCTIONS ===========================================
    ERC20 private constant WETH = ERC20(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2);

    /**
     * @notice Attempted to update the asset to one that is not supported by the platform.
     * @param asset address of the unsupported asset
     */
    error PriceRouter__UnsupportedAsset(address asset);

    /**
     * @notice Gets the exchange rate between a base and a quote asset
     * @param baseAsset the asset to convert into quoteAsset
     * @param quoteAsset the asset base asset is converted into
     * @return exchangeRate value of base asset in terms of quote asset
     */
    function _getExchangeRate(
        ERC20 baseAsset,
        AssetSettings memory baseSettings,
        ERC20 quoteAsset,
        AssetSettings memory quoteSettings,
        uint8 quoteAssetDecimals,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        uint256 basePrice = _getPriceInUSD(baseAsset, baseSettings, cache);
        uint256 quotePrice = _getPriceInUSD(quoteAsset, quoteSettings, cache);
        uint256 exchangeRate = basePrice.mulDivDown(10**quoteAssetDecimals, quotePrice);
        return exchangeRate;
    }

    /**
     * @notice Helper function to get an assets price in USD.
     * @dev Returns price in USD with 8 decimals.
     * @dev Favors using cached prices if available.
     */
    function _getPriceInUSD(
        ERC20 asset,
        AssetSettings memory settings,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        // First check if the price is in the price cache.
        uint8 lastIndex = PRICE_CACHE_SIZE;
        for (uint8 i; i < PRICE_CACHE_SIZE; ++i) {
            // Did not find our price in the cache.
            if (cache[i].asset == address(0)) {
                // Save the last index.
                lastIndex = i;
                break;
            }
            // Did find our price in the cache.
            if (cache[i].asset == address(asset)) return cache[i].price;
        }

        // Call get price function using appropriate derivative.
        uint256 price;
        if (settings.derivative == 1) {
            price = _getPriceForChainlinkDerivative(asset, settings.source, cache);
        } else if (settings.derivative == 2) {
            price = _getPriceForCurveDerivative(asset, settings.source, cache);
        } else if (settings.derivative == 3) {
            price = _getPriceForCurveV2Derivative(asset, settings.source, cache);
        } else if (settings.derivative == 4) {
            price = _getPriceForAaveDerivative(asset, settings.source, cache);
        } else revert PriceRouter__UnkownDerivative(settings.derivative);

        // If there is room in the cache, the price fits in a uint96, then find the next spot available.
        if (lastIndex < PRICE_CACHE_SIZE && price <= type(uint96).max) {
            for (uint8 i = lastIndex; i < PRICE_CACHE_SIZE; ++i) {
                // Found an empty cache slot, so fill it.
                if (cache[i].asset == address(0)) {
                    cache[i] = PriceCache(address(asset), uint96(price));
                    break;
                }
            }
        }

        return price;
    }

    /**
     * @notice math function that preserves precision by multiplying the amountBase before dividing.
     * @param priceBaseUSD the base asset price in USD
     * @param priceQuoteUSD the quote asset price in USD
     * @param baseDecimals the base asset decimals
     * @param quoteDecimals the quote asset decimals
     * @param amountBase the amount of base asset
     */
    function _getValueInQuote(
        uint256 priceBaseUSD,
        uint256 priceQuoteUSD,
        uint8 baseDecimals,
        uint8 quoteDecimals,
        uint256 amountBase
    ) internal pure returns (uint256 valueInQuote) {
        // Get value in quote asset, but maintain as much precision as possible.
        // Cleaner equations below.
        // baseToUSD = amountBase * priceBaseUSD / 10**baseDecimals.
        // valueInQuote = baseToUSD * 10**quoteDecimals / priceQuoteUSD
        valueInQuote = amountBase.mulDivDown((priceBaseUSD * 10**quoteDecimals), (10**baseDecimals * priceQuoteUSD));
    }

    /**
     * @notice Attempted an operation with arrays of unequal lengths that were expected to be equal length.
     */
    error PriceRouter__LengthMismatch();

    /**
     * @notice Get the total value of multiple assets in terms of another asset.
     * @param baseAssets addresses of the assets to get the price of in terms of the quote asset
     * @param amounts amounts of each base asset to price
     * @param quoteAsset address of the assets that the base asset is priced in terms of
     * @return value total value of the amounts of each base assets specified in terms of the quote asset
     */
    function _getValues(
        ERC20[] calldata baseAssets,
        uint256[] calldata amounts,
        ERC20 quoteAsset,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        if (baseAssets.length != amounts.length) revert PriceRouter__LengthMismatch();
        uint256 quotePrice;
        {
            AssetSettings memory quoteSettings = getAssetSettings[quoteAsset];
            if (quoteSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(quoteAsset));
            quotePrice = _getPriceInUSD(quoteAsset, quoteSettings, cache);
        }
        uint256 valueInQuote;
        // uint256 price;
        uint8 quoteDecimals = quoteAsset.decimals();

        for (uint8 i = 0; i < baseAssets.length; i++) {
            // Skip zero amount values.
            if (amounts[i] == 0) continue;
            ERC20 baseAsset = baseAssets[i];
            if (baseAsset == quoteAsset) valueInQuote += amounts[i];
            else {
                uint256 basePrice;
                {
                    AssetSettings memory baseSettings = getAssetSettings[baseAsset];
                    if (baseSettings.derivative == 0) revert PriceRouter__UnsupportedAsset(address(baseAsset));
                    basePrice = _getPriceInUSD(baseAsset, baseSettings, cache);
                }
                valueInQuote += _getValueInQuote(
                    basePrice,
                    quotePrice,
                    baseAsset.decimals(),
                    quoteDecimals,
                    amounts[i]
                );
                // uint256 valueInUSD = (amounts[i].mulDivDown(price, 10**baseAsset.decimals()));
                // valueInQuote += valueInUSD.mulDivDown(10**quoteDecimals, quotePrice);
            }
        }
        return valueInQuote;
    }

    // =========================================== CHAINLINK PRICE DERIVATIVE ===========================================\
    /**
     * @notice Stores data for Chainlink derivative assets.
     * @param max the max valid price of the asset
     * @param min the min valid price of the asset
     * @param heartbeat the max amount of time between price updates
     * @param inETH bool indicating whether the price feed is
     *        denominated in ETH(true) or USD(false)
     */
    struct ChainlinkDerivativeStorage {
        uint144 max;
        uint80 min;
        uint24 heartbeat;
        bool inETH;
    }
    /**
     * @notice Returns Chainlink Derivative Storage
     */
    mapping(ERC20 => ChainlinkDerivativeStorage) public getChainlinkDerivativeStorage;

    /**
     * @notice If zero is specified for a Chainlink asset heartbeat, this value is used instead.
     */
    uint24 public constant DEFAULT_HEART_BEAT = 1 days;

    /**
     * @notice Setup function for pricing Chainlink derivative assets.
     * @dev _source The address of the Chainlink Data feed.
     * @dev _storage A ChainlinkDerivativeStorage value defining valid prices.
     */
    function _setupPriceForChainlinkDerivative(
        ERC20 _asset,
        address _source,
        bytes memory _storage
    ) internal {
        ChainlinkDerivativeStorage memory parameters = abi.decode(_storage, (ChainlinkDerivativeStorage));

        // Use Chainlink to get the min and max of the asset.
        IChainlinkAggregator aggregator = IChainlinkAggregator(IChainlinkAggregator(_source).aggregator());
        uint256 minFromChainklink = uint256(uint192(aggregator.minAnswer()));
        uint256 maxFromChainlink = uint256(uint192(aggregator.maxAnswer()));

        // Add a ~10% buffer to minimum and maximum price from Chainlink because Chainlink can stop updating
        // its price before/above the min/max price.
        uint256 bufferedMinPrice = (minFromChainklink * 1.1e18) / 1e18;
        uint256 bufferedMaxPrice = (maxFromChainlink * 0.9e18) / 1e18;

        if (parameters.min == 0) {
            // Revert if bufferedMinPrice overflows because uint80 is too small to hold the minimum price,
            // and lowering it to uint80 is not safe because the price feed can stop being updated before
            // it actually gets to that lower price.
            if (bufferedMinPrice > type(uint80).max) revert("Buffered Min Overflow");
            parameters.min = uint80(bufferedMinPrice);
        } else {
            if (parameters.min < bufferedMinPrice)
                revert PriceRouter__InvalidMinPrice(parameters.min, bufferedMinPrice);
        }

        if (parameters.max == 0) {
            //Do not revert even if bufferedMaxPrice is greater than uint144, because lowering it to uint144 max is more conservative.
            parameters.max = bufferedMaxPrice > type(uint144).max ? type(uint144).max : uint144(bufferedMaxPrice);
        } else {
            if (parameters.max > bufferedMaxPrice)
                revert PriceRouter__InvalidMaxPrice(parameters.max, bufferedMaxPrice);
        }

        if (parameters.min >= parameters.max)
            revert PriceRouter__MinPriceGreaterThanMaxPrice(parameters.min, parameters.max);

        parameters.heartbeat = parameters.heartbeat != 0 ? parameters.heartbeat : DEFAULT_HEART_BEAT;

        getChainlinkDerivativeStorage[_asset] = parameters;
    }

    /**
     * @notice Get the price of a Chainlink derivative in terms of USD.
     */
    function _getPriceForChainlinkDerivative(
        ERC20 _asset,
        address _source,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        ChainlinkDerivativeStorage memory parameters = getChainlinkDerivativeStorage[_asset];
        IChainlinkAggregator aggregator = IChainlinkAggregator(_source);
        (, int256 _price, , uint256 _timestamp, ) = aggregator.latestRoundData();
        uint256 price = _price.toUint256();
        _checkPriceFeed(address(_asset), price, _timestamp, parameters.max, parameters.min, parameters.heartbeat);
        // If price is in ETH, then convert price into USD.
        if (parameters.inETH) {
            uint256 _ethToUsd = _getPriceInUSD(WETH, getAssetSettings[WETH], cache);
            price = price.mulWadDown(_ethToUsd);
        }
        return price;
    }

    /**
     * @notice Attempted an operation to price an asset that under its minimum valid price.
     * @param asset address of the asset that is under its minimum valid price
     * @param price price of the asset
     * @param minPrice minimum valid price of the asset
     */
    error PriceRouter__AssetBelowMinPrice(address asset, uint256 price, uint256 minPrice);

    /**
     * @notice Attempted an operation to price an asset that under its maximum valid price.
     * @param asset address of the asset that is under its maximum valid price
     * @param price price of the asset
     * @param maxPrice maximum valid price of the asset
     */
    error PriceRouter__AssetAboveMaxPrice(address asset, uint256 price, uint256 maxPrice);

    /**
     * @notice Attempted to fetch a price for an asset that has not been updated in too long.
     * @param asset address of the asset thats price is stale
     * @param timeSinceLastUpdate seconds since the last price update
     * @param heartbeat maximum allowed time between price updates
     */
    error PriceRouter__StalePrice(address asset, uint256 timeSinceLastUpdate, uint256 heartbeat);

    /**
     * @notice helper function to validate a price feed is safe to use.
     * @param asset ERC20 asset price feed data is for.
     * @param value the price value the price feed gave.
     * @param timestamp the last timestamp the price feed was updated.
     * @param max the upper price bound
     * @param min the lower price bound
     * @param heartbeat the max amount of time between price updates
     */
    function _checkPriceFeed(
        address asset,
        uint256 value,
        uint256 timestamp,
        uint144 max,
        uint88 min,
        uint24 heartbeat
    ) internal view {
        if (value < min) revert PriceRouter__AssetBelowMinPrice(address(asset), value, min);

        if (value > max) revert PriceRouter__AssetAboveMaxPrice(address(asset), value, max);

        uint256 timeSinceLastUpdate = block.timestamp - timestamp;
        if (timeSinceLastUpdate > heartbeat)
            revert PriceRouter__StalePrice(address(asset), timeSinceLastUpdate, heartbeat);
    }

    // ======================================== CURVE VIRTUAL PRICE BOUND ========================================
    /**
     * @notice Curve virtual price is susceptible to re-entrancy attacks, if the attacker adds/removes pool liquidity,
     *         and re-enters into one of our contracts. To mitigate this, all curve pricing operations check
     *         the current `pool.get_virtual_price()` against logical bounds.
     * @notice These logical bounds are updated when `addAsset` is called, or Chainlink Automation detects that
     *         the bounds need to be updated, and that the gas price is reasonable.
     * @notice Once the on chain virtual price goes out of bounds, all pricing operations will revert for that Curve LP,
     *         which means any Cellars using that Curve LP are effectively frozen until the virtual price bounds are updated
     *         by Chainlink. If this is not happening in a timely manner( IE network is abnormally busy), the owner of this
     *         contract can raise the `gasConstant` to a value that better reflects the floor gas price of the network.
     *         Which will cause Chainlink nodes to update virtual price bounds faster.
     */

    /**
     * @param datum the virtual price to base posDelta and negDelta off of, 8 decimals
     * @param timeLastUpdated the timestamp this datum was updated
     * @param posDelta multipler >= 1e8 defining the logical upper bound for this virtual price, 8 decimals
     * @param negDelta multipler <= 1e8 defining the logical lower bound for this virtual price, 8 decimals
     * @param rateLimit the minimum amount of time that must pass between updates
     * @dev Curve virtual price values should update slowly, hence why this contract enforces a rate limit.
     * @dev During datum updates, the max/min new datum corresponds to the current upper/lower bound.
     */
    struct VirtualPriceBound {
        uint96 datum;
        uint64 timeLastUpdated;
        uint32 posDelta;
        uint32 negDelta;
        uint32 rateLimit;
    }

    /**
     * @notice Returns a Curve asset virtual price bound
     */
    mapping(address => VirtualPriceBound) public getVirtualPriceBound;

    /**
     * @dev If ZERO is specified for an assets `rateLimit` this value is used instead.
     */
    uint32 public constant DEFAULT_RATE_LIMIT = 1 days;

    /**
     * @notice Chainlink Fast Gas Feed for ETH Mainnet.
     */
    address public ETH_FAST_GAS_FEED = 0x169E633A2D1E6c10dD91238Ba11c4A708dfEF37C;

    /**
     * @notice Allows owner to set a new gas feed.
     * @notice Can be set to zero address to skip gas check.
     */
    function setGasFeed(address gasFeed) external onlyOwner {
        ETH_FAST_GAS_FEED = gasFeed;
    }

    /**
     * @notice Dictates how aggressive keepers are with updating Curve pool virtual price values.
     * @dev A larger `gasConstant` will raise the `gasPriceLimit`, while a smaller `gasConstant`
     *      will lower the `gasPriceLimit`.
     */
    uint256 public gasConstant = 200e9;

    /**
     * @notice Allows owner to set a new gas constant.
     */
    function setGasConstant(uint256 newConstant) external onlyOwner {
        gasConstant = newConstant;
    }

    /**
     * @notice Dictates the minimum delta required for an upkeep.
     * @dev If the max delta found is less than this, then checkUpkeep returns false.
     */
    uint256 public minDelta = 0.05e18;

    /**
     * @notice Allows owner to set a new minimum delta.
     */
    function setMinDelta(uint256 newMinDelta) external onlyOwner {
        minDelta = newMinDelta;
    }

    /**
     * @notice Stores all Curve Assets this contract prices, so Automation can loop through it.
     */
    address[] public curveAssets;

    /**
     * @notice Allows owner to update a Curve asset's virtual price parameters..
     */
    function updateVirtualPriceBound(
        address _asset,
        uint32 _posDelta,
        uint32 _negDelta,
        uint32 _rateLimit
    ) external onlyOwner {
        VirtualPriceBound storage vpBound = getVirtualPriceBound[_asset];
        vpBound.posDelta = _posDelta;
        vpBound.negDelta = _negDelta;
        vpBound.rateLimit = _rateLimit == 0 ? DEFAULT_RATE_LIMIT : _rateLimit;
    }

    /**
     * @notice Logic ran by Chainlink Automation to determine if virtual price bounds need to be updated.
     * @dev `checkData` should be a start and end value indicating where to start and end in the `curveAssets` array.
     * @dev The end index can be zero, or greater than the current length of `curveAssets`.
     *      Doing this makes end = curveAssets.length.
     * @dev `performData` is the target index in `curveAssets` that needs its bounds updated.
     */
    function _checkVirtualPriceBound(bytes memory checkData)
        internal
        view
        returns (bool upkeepNeeded, bytes memory performData)
    {
        // Decode checkData to get start and end index.
        (uint256 start, uint256 end) = abi.decode(checkData, (uint256, uint256));
        if (end == 0 || end > curveAssets.length) end = curveAssets.length;

        // Loop through all curve assets, and find the asset with the largest delta(the one that needs to be updated the most).
        uint256 maxDelta;
        uint256 targetIndex;
        for (uint256 i = start; i < end; i++) {
            address asset = curveAssets[i];
            VirtualPriceBound memory vpBound = getVirtualPriceBound[asset];

            // Check to see if this virtual price was updated recently.
            if ((block.timestamp - vpBound.timeLastUpdated) < vpBound.rateLimit) continue;

            // Check current virtual price against upper and lower bounds to find the delta.
            uint256 currentVirtualPrice = ICurvePool(getAssetSettings[ERC20(asset)].source).get_virtual_price();
            currentVirtualPrice = currentVirtualPrice.changeDecimals(18, 8);
            uint256 delta;
            if (currentVirtualPrice > vpBound.datum) {
                uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
                uint256 ceiling = upper - vpBound.datum;
                uint256 current = currentVirtualPrice - vpBound.datum;
                delta = _getDelta(ceiling, current);
            } else {
                uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
                uint256 ceiling = vpBound.datum - lower;
                uint256 current = vpBound.datum - currentVirtualPrice;
                delta = _getDelta(ceiling, current);
            }
            // Save the largest delta for the upkeep.
            if (delta > maxDelta) {
                maxDelta = delta;
                targetIndex = i;
            }
        }

        // If the largest delta must be greater/equal to `minDelta` to continue.
        if (maxDelta >= minDelta) {
            // If gas feed is not set, skip the gas check.
            if (ETH_FAST_GAS_FEED == address(0)) {
                // No Gas Check needed.
                upkeepNeeded = true;
                performData = abi.encode(targetIndex);
            } else {
                // Run a gas check to determine if it makes sense to update the target curve asset.
                uint256 gasPriceLimit = gasConstant.mulDivDown(maxDelta**3, 1e54); // 54 comes from 18 * 3.
                uint256 currentGasPrice = uint256(IChainlinkAggregator(ETH_FAST_GAS_FEED).latestAnswer());
                if (currentGasPrice <= gasPriceLimit) {
                    upkeepNeeded = true;
                    performData = abi.encode(targetIndex);
                }
            }
        }
    }

    /**
     * @notice Attempted to call a function only the Chainlink Registry can call.
     */
    error PriceRouter__OnlyAutomationRegistry();

    /**
     * @notice Attempted to update a virtual price too soon.
     */
    error PriceRouter__VirtualPriceRateLimiter();

    /**
     * @notice Attempted to update a virtual price bound that did not need to be updated.
     */
    error PriceRouter__NothingToUpdate();

    /**
     * @notice Chainlink's Automation Registry contract address.
     */
    address public automationRegistry = 0x02777053d6764996e594c3E88AF1D58D5363a2e6;

    /**
     * @notice Allows owner to update the Automation Registry.
     * @dev In rare cases, Chainlink's registry CAN change.
     */
    function setAutomationRegistry(address newRegistry) external onlyOwner {
        automationRegistry = newRegistry;
    }

    /**
     * @notice Curve virtual price is susceptible to re-entrancy attacks, if the attacker adds/removes pool liquidity.
     *         To stop this we check the virtual price against logical bounds.
     * @dev Only the chainlink registry can call this function, so we know that Chainlink nodes will not be
     *      re-entering into the Curve pool, so it is safe to use the current on chain virtual price.
     * @notice Updating the virtual price is rate limited by `VirtualPriceBound.raetLimit` and can only be
     *         updated at most to the lower or upper bound of the current datum.
     *         This is intentional since curve pool price should not be volatile, and if they are, then
     *         we WANT that Curve LP pools TX pricing to revert.
     */
    function _updateVirtualPriceBound(bytes memory performData) internal {
        // Make sure only the Automation Registry can call this function.
        if (msg.sender != automationRegistry) revert PriceRouter__OnlyAutomationRegistry();

        // Grab the target index from performData.
        uint256 index = abi.decode(performData, (uint256));
        address asset = curveAssets[index];
        VirtualPriceBound storage vpBound = getVirtualPriceBound[asset];

        // Enfore rate limit check.
        if ((block.timestamp - vpBound.timeLastUpdated) < vpBound.rateLimit)
            revert PriceRouter__VirtualPriceRateLimiter();

        // Determine what the new Datum should be.
        uint256 currentVirtualPrice = ICurvePool(getAssetSettings[ERC20(asset)].source).get_virtual_price();
        currentVirtualPrice = currentVirtualPrice.changeDecimals(18, 8);
        if (currentVirtualPrice > vpBound.datum) {
            uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
            vpBound.datum = uint96(currentVirtualPrice > upper ? upper : currentVirtualPrice);
        } else if (currentVirtualPrice < vpBound.datum) {
            uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
            vpBound.datum = uint96(currentVirtualPrice < lower ? lower : currentVirtualPrice);
        } else {
            revert PriceRouter__NothingToUpdate();
        }

        // Update the stored timestamp.
        vpBound.timeLastUpdated = uint64(block.timestamp);
    }

    /**
     * @notice Returns a percent delta representing where `current` is in reference to `ceiling`.
     * Example, if current == 0, this would return a 0.
     *          if current == ceiling, this would return a 1e18.
     *          if current == (ceiling) / 2, this would return 0.5e18.
     */
    function _getDelta(uint256 ceiling, uint256 current) internal pure returns (uint256) {
        return current.mulDivDown(1e18, ceiling);
    }

    /**
     * @notice Attempted to price a curve asset that was below its logical minimum price.
     */
    error PriceRouter__CurrentBelowLowerBound(uint256 current, uint256 lower);

    /**
     * @notice Attempted to price a curve asset that was above its logical maximum price.
     */
    error PriceRouter__CurrentAboveUpperBound(uint256 current, uint256 upper);

    /**
     * @notice Enforces a logical price bound on Curve pool tokens.
     */
    function _checkBounds(
        uint256 lower,
        uint256 upper,
        uint256 current
    ) internal pure {
        if (current < lower) revert PriceRouter__CurrentBelowLowerBound(current, lower);
        if (current > upper) revert PriceRouter__CurrentAboveUpperBound(current, upper);
    }

    // =========================================== CURVE PRICE DERIVATIVE ===========================================
    /**
     * @notice Curve Derivative Storage
     * @dev Stores an array of the underlying token addresses in the curve pool.
     */
    mapping(ERC20 => address[]) public getCurveDerivativeStorage;

    /**
     * @notice Setup function for pricing Curve derivative assets.
     * @dev _source The address of the Curve Pool.
     * @dev _storage A VirtualPriceBound value for this asset.
     * @dev Assumes that curve pools never add or remove tokens.
     */
    function _setupPriceForCurveDerivative(
        ERC20 _asset,
        address _source,
        bytes memory _storage
    ) internal {
        ICurvePool pool = ICurvePool(_source);
        uint8 coinsLength = 0;
        // Figure out how many tokens are in the curve pool.
        while (true) {
            try pool.coins(coinsLength) {
                coinsLength++;
            } catch {
                break;
            }
        }

        // Save the pools tokens to reduce gas for pricing calls.
        address[] memory coins = new address[](coinsLength);
        for (uint256 i = 0; i < coinsLength; i++) {
            coins[i] = pool.coins(i);
        }

        getCurveDerivativeStorage[_asset] = coins;

        curveAssets.push(address(_asset));

        // Setup virtual price bound.
        VirtualPriceBound memory vpBound = abi.decode(_storage, (VirtualPriceBound));
        uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
        upper = upper.changeDecimals(8, 18);
        uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
        lower = lower.changeDecimals(8, 18);
        _checkBounds(lower, upper, pool.get_virtual_price());
        if (vpBound.rateLimit == 0) vpBound.rateLimit = DEFAULT_RATE_LIMIT;
        vpBound.timeLastUpdated = uint64(block.timestamp);
        getVirtualPriceBound[address(_asset)] = vpBound;
    }

    /**
     * @notice Get the price of a CurveV1 derivative in terms of USD.
     */
    function _getPriceForCurveDerivative(
        ERC20 asset,
        address _source,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256 price) {
        ICurvePool pool = ICurvePool(_source);

        address[] memory coins = getCurveDerivativeStorage[asset];

        uint256 minPrice = type(uint256).max;
        for (uint256 i = 0; i < coins.length; i++) {
            ERC20 poolAsset = ERC20(coins[i]);
            uint256 tokenPrice = _getPriceInUSD(poolAsset, getAssetSettings[poolAsset], cache);
            if (tokenPrice < minPrice) minPrice = tokenPrice;
        }

        if (minPrice == type(uint256).max) revert("Min price not found.");

        // Check that virtual price is within bounds.
        uint256 virtualPrice = pool.get_virtual_price();
        VirtualPriceBound memory vpBound = getVirtualPriceBound[address(asset)];
        uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
        upper = upper.changeDecimals(8, 18);
        uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
        lower = lower.changeDecimals(8, 18);
        _checkBounds(lower, upper, virtualPrice);

        // Virtual price is based off the Curve Token decimals.
        uint256 curveTokenDecimals = ERC20(asset).decimals();
        price = minPrice.mulDivDown(virtualPrice, 10**curveTokenDecimals);
    }

    // =========================================== CURVEV2 PRICE DERIVATIVE ===========================================

    /**
     * @notice Setup function for pricing CurveV2 derivative assets.
     * @dev _source The address of the CurveV2 Pool.
     * @dev _storage A VirtualPriceBound value for this asset.
     * @dev Assumes that curve pools never add or remove tokens.
     */
    function _setupPriceForCurveV2Derivative(
        ERC20 _asset,
        address _source,
        bytes memory _storage
    ) internal {
        ICurvePool pool = ICurvePool(_source);
        uint8 coinsLength = 0;
        // Figure out how many tokens are in the curve pool.
        while (true) {
            try pool.coins(coinsLength) {
                coinsLength++;
            } catch {
                break;
            }
        }
        address[] memory coins = new address[](coinsLength);
        for (uint256 i = 0; i < coinsLength; i++) {
            coins[i] = pool.coins(i);
        }

        getCurveDerivativeStorage[_asset] = coins;

        curveAssets.push(address(_asset));

        // Setup virtual price bound.
        VirtualPriceBound memory vpBound = abi.decode(_storage, (VirtualPriceBound));
        uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
        upper = upper.changeDecimals(8, 18);
        uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
        lower = lower.changeDecimals(8, 18);
        _checkBounds(lower, upper, pool.get_virtual_price());
        if (vpBound.rateLimit == 0) vpBound.rateLimit = DEFAULT_RATE_LIMIT;
        vpBound.timeLastUpdated = uint64(block.timestamp);
        getVirtualPriceBound[address(_asset)] = vpBound;
    }

    uint256 private constant GAMMA0 = 28000000000000;
    uint256 private constant A0 = 2 * 3**3 * 10000;
    uint256 private constant DISCOUNT0 = 1087460000000000;

    // x has 36 decimals
    // result has 18 decimals.
    function _cubicRoot(uint256 x) internal pure returns (uint256) {
        uint256 D = x / 1e18;
        for (uint8 i; i < 256; i++) {
            uint256 diff;
            uint256 D_prev = D;
            D = (D * (2 * 1e18 + ((((x / D) * 1e18) / D) * 1e18) / D)) / (3 * 1e18);
            if (D > D_prev) diff = D - D_prev;
            else diff = D_prev - D;
            if (diff <= 1 || diff * 10**18 < D) return D;
        }
        revert("Did not converge");
    }

    /**
     * Inspired by https://etherscan.io/address/0xE8b2989276E2Ca8FDEA2268E3551b2b4B2418950#code
     * @notice Get the price of a CurveV1 derivative in terms of USD.
     */
    function _getPriceForCurveV2Derivative(
        ERC20 asset,
        address _source,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        ICurvePool pool = ICurvePool(_source);

        // Check that virtual price is within bounds.
        uint256 virtualPrice = pool.get_virtual_price();
        VirtualPriceBound memory vpBound = getVirtualPriceBound[address(asset)];
        uint256 upper = uint256(vpBound.datum).mulDivDown(vpBound.posDelta, 1e8);
        upper = upper.changeDecimals(8, 18);
        uint256 lower = uint256(vpBound.datum).mulDivDown(vpBound.negDelta, 1e8);
        lower = lower.changeDecimals(8, 18);
        _checkBounds(lower, upper, virtualPrice);

        address[] memory coins = getCurveDerivativeStorage[asset];
        ERC20 token0 = ERC20(coins[0]);
        if (coins.length == 2) {
            return pool.lp_price().mulDivDown(_getPriceInUSD(token0, getAssetSettings[token0], cache), 1e18);
        } else if (coins.length == 3) {
            uint256 t1Price = pool.price_oracle(0);
            uint256 t2Price = pool.price_oracle(1);

            uint256 maxPrice = (3 * virtualPrice * _cubicRoot(t1Price * t2Price)) / 1e18;
            {
                uint256 g = pool.gamma().mulDivDown(1e18, GAMMA0);
                uint256 a = pool.A().mulDivDown(1e18, A0);
                uint256 coefficient = (g**2 / 1e18) * a;
                uint256 discount = coefficient > 1e34 ? coefficient : 1e34;
                discount = _cubicRoot(discount).mulDivDown(DISCOUNT0, 1e18);

                maxPrice -= maxPrice.mulDivDown(discount, 1e18);
            }
            return maxPrice.mulDivDown(_getPriceInUSD(token0, getAssetSettings[token0], cache), 1e18);
        } else revert("Unsupported Pool");
    }

    // =========================================== AAVE PRICE DERIVATIVE ===========================================
    /**
     * @notice Aave Derivative Storage
     */
    mapping(ERC20 => ERC20) public getAaveDerivativeStorage;

    /**
     * @notice Setup function for pricing Aave derivative assets.
     * @dev _source The address of the aToken.
     * @dev _storage is not used.
     */
    function _setupPriceForAaveDerivative(
        ERC20 _asset,
        address _source,
        bytes memory
    ) internal {
        IAaveToken aToken = IAaveToken(_source);
        getAaveDerivativeStorage[_asset] = ERC20(aToken.UNDERLYING_ASSET_ADDRESS());
    }

    /**
     * @notice Get the price of an Aave derivative in terms of USD.
     */
    function _getPriceForAaveDerivative(
        ERC20 asset,
        address,
        PriceCache[PRICE_CACHE_SIZE] memory cache
    ) internal view returns (uint256) {
        asset = getAaveDerivativeStorage[asset];
        return _getPriceInUSD(asset, getAssetSettings[asset], cache);
    }
}

// File: src/utils/Math.sol



// SPDX-License-Identifier: Apache-2.0
pragma solidity 0.8.16;

library Math {
    /**
     * @notice Substract with a floor of 0 for the result.
     */
    function subMinZero(uint256 x, uint256 y) internal pure returns (uint256) {
        return x > y ? x - y : 0;
    }

    /**
     * @notice Used to change the decimals of precision used for an amount.
     */
    function changeDecimals(
        uint256 amount,
        uint8 fromDecimals,
        uint8 toDecimals
    ) internal pure returns (uint256) {
        if (fromDecimals == toDecimals) {
            return amount;
        } else if (fromDecimals < toDecimals) {
            return amount * 10**(toDecimals - fromDecimals);
        } else {
            return amount / 10**(fromDecimals - toDecimals);
        }
    }

    // ===================================== OPENZEPPELIN'S MATH =====================================

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

    // ================================= SOLMATE's FIXEDPOINTMATHLIB =================================

    uint256 public constant WAD = 1e18; // The scalar of ETH and most ERC20s.

    function mulWadDown(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
    }

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // Divide z by the denominator.
            z := div(z, denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // First, divide z - 1 by the denominator and add 1.
            // We allow z - 1 to underflow if z is 0, because we multiply the
            // end result by 0 if z is zero, ensuring we return 0 if z is zero.
            z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
        }
    }
}