Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0 || ^0.8.0;

interface IFxTreasury {
  /**********
   * Events *
   **********/

  /// @notice Emitted when the net asset value is updated.
  /// @param price The new price of base token.
  /// @param fNav The new net asset value of fToken.
  event ProtocolSettle(uint256 price, uint256 fNav);

  /*********
   * Enums *
   *********/

  enum MintOption {
    Both,
    FToken,
    XToken
  }

  /*************************
   * Public View Functions *
   *************************/

  /// @notice Return the address of base token.
  function baseToken() external view returns (address);

  /// @notice Return the address fractional base token.
  function fToken() external view returns (address);

  /// @notice Return the address leveraged base token.
  function xToken() external view returns (address);

  /// @notice Return the address of strategy contract.
  function strategy() external view returns (address);

  /// @notice The last updated permissioned base token price.
  function lastPermissionedPrice() external view returns (uint256);

  /// @notice Return the total amount of base token deposited.
  function totalBaseToken() external view returns (uint256);

  /// @notice Return the total amount of base token managed by strategy.
  function strategyUnderlying() external view returns (uint256);

  /// @notice Return the current collateral ratio of fToken, multipled by 1e18.
  function collateralRatio() external view returns (uint256);

  /// @notice Convert unwrapped token amount to wrapped token amount.
  /// @param amount The unwrapped token amount.
  function convertToWrapped(uint256 amount) external view returns (uint256);

  /// @notice Convert wrapped token amount to unwrapped token amount.
  /// @param amount The wrapped token amount.
  function convertToUnwrapped(uint256 amount) external view returns (uint256);

  /// @notice Return current nav for base token, fToken and xToken.
  /// @return baseNav The nav for base token.
  /// @return fNav The nav for fToken.
  /// @return xNav The nav for xToken.
  function getCurrentNav()
    external
    view
    returns (
      uint256 baseNav,
      uint256 fNav,
      uint256 xNav
    );

  /// @notice Compute the amount of base token needed to reach the new collateral ratio.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @return maxBaseIn The amount of base token needed.
  /// @return maxFTokenMintable The amount of fToken can be minted.
  function maxMintableFToken(uint256 newCollateralRatio)
    external
    view
    returns (uint256 maxBaseIn, uint256 maxFTokenMintable);

  /// @notice Compute the amount of base token needed to reach the new collateral ratio.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @return maxBaseIn The amount of base token needed.
  /// @return maxXTokenMintable The amount of xToken can be minted.
  function maxMintableXToken(uint256 newCollateralRatio)
    external
    view
    returns (uint256 maxBaseIn, uint256 maxXTokenMintable);

  /// @notice Compute the amount of base token needed to reach the new collateral ratio, with incentive.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @param incentiveRatio The extra incentive ratio, multipled by 1e18.
  /// @return maxBaseIn The amount of base token needed.
  /// @return maxXTokenMintable The amount of xToken can be minted.
  function maxMintableXTokenWithIncentive(uint256 newCollateralRatio, uint256 incentiveRatio)
    external
    view
    returns (uint256 maxBaseIn, uint256 maxXTokenMintable);

  /// @notice Compute the amount of fToken needed to reach the new collateral ratio.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @return maxBaseOut The amount of base token redeemed.
  /// @return maxFTokenRedeemable The amount of fToken needed.
  function maxRedeemableFToken(uint256 newCollateralRatio)
    external
    view
    returns (uint256 maxBaseOut, uint256 maxFTokenRedeemable);

  /// @notice Compute the amount of xToken needed to reach the new collateral ratio.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @return maxBaseOut The amount of base token redeemed.
  /// @return maxXTokenRedeemable The amount of xToken needed.
  function maxRedeemableXToken(uint256 newCollateralRatio)
    external
    view
    returns (uint256 maxBaseOut, uint256 maxXTokenRedeemable);

  /// @notice Compute the maximum amount of fToken can be liquidated.
  /// @param newCollateralRatio The target collateral ratio, multipled by 1e18.
  /// @param incentiveRatio The extra incentive ratio, multipled by 1e18.
  /// @return maxBaseOut The maximum amount of base token can liquidate, without incentive.
  /// @return maxFTokenLiquidatable The maximum amount of fToken can be liquidated.
  function maxLiquidatable(uint256 newCollateralRatio, uint256 incentiveRatio)
    external
    view
    returns (uint256 maxBaseOut, uint256 maxFTokenLiquidatable);

  /// @notice Return the exponential moving average of the leverage ratio.
  function leverageRatio() external view returns (uint256);

  /****************************
   * Public Mutated Functions *
   ****************************/

  /// @notice Mint fToken and xToken with some base token.
  /// @param baseIn The amount of base token deposited.
  /// @param recipient The address of receiver.
  /// @param option The mint option, xToken or fToken or both.
  /// @return fTokenOut The amount of fToken minted.
  /// @return xTokenOut The amount of xToken minted.
  function mint(
    uint256 baseIn,
    address recipient,
    MintOption option
  ) external returns (uint256 fTokenOut, uint256 xTokenOut);

  /// @notice Redeem fToken and xToken to base tokne.
  /// @param fTokenIn The amount of fToken to redeem.
  /// @param xTokenIn The amount of xToken to redeem.
  /// @param owner The owner of the fToken or xToken.
  /// @param baseOut The amount of base token redeemed.
  function redeem(
    uint256 fTokenIn,
    uint256 xTokenIn,
    address owner
  ) external returns (uint256 baseOut);

  /// @notice Add some base token to mint xToken with incentive.
  /// @param baseIn The amount of base token deposited.
  /// @param incentiveRatio The incentive ratio.
  /// @param recipient The address of receiver.
  /// @return xTokenOut The amount of xToken minted.
  function addBaseToken(
    uint256 baseIn,
    uint256 incentiveRatio,
    address recipient
  ) external returns (uint256 xTokenOut);

  /// @notice Liquidate fToken to base token with incentive.
  /// @param fTokenIn The amount of fToken to liquidate.
  /// @param incentiveRatio The incentive ratio.
  /// @param owner The owner of the fToken.
  /// @param baseOut The amount of base token liquidated.
  function liquidate(
    uint256 fTokenIn,
    uint256 incentiveRatio,
    address owner
  ) external returns (uint256 baseOut);

  /// @notice Settle the nav of base token, fToken and xToken.
  function protocolSettle() external;

  /// @notice Transfer some base token to strategy contract.
  /// @param amount The amount of token to transfer.
  function transferToStrategy(uint256 amount) external;

  /// @notice Notify base token profit from strategy contract.
  /// @param amount The amount of base token.
  function notifyStrategyProfit(uint256 amount) external;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0 || ^0.8.0;

// solhint-disable func-name-mixedcase
// solhint-disable var-name-mixedcase

interface ICurveTokenMinter {
  function token() external view returns (address);

  function controller() external view returns (address);

  function minted(address _user, address _gauge) external view returns (uint256);

  function allowed_to_mint_for(address _minter, address _user) external view returns (bool);

  function mint(address gauge_addr) external;

  function mint_many(address[8] memory gauge_addrs) external;

  function mint_for(address gauge_addr, address _for) external;

  function toggle_approve_mint(address minting_user) external;
}

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

pragma solidity ^0.8.1;

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

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

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

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

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)
            }
        } else {
            revert(errorMessage);
        }
    }
}

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

pragma solidity ^0.8.0;

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

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

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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

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

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

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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable2Step.sol)

pragma solidity ^0.8.0;

import "./Ownable.sol";

/**
 * @dev Contract module which provides 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} and {acceptOwnership}.
 *
 * This module is used through inheritance. It will make available all functions
 * from parent (Ownable).
 */
abstract contract Ownable2Step is Ownable {
    address private _pendingOwner;

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

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

    /**
     * @dev Starts the ownership transfer of the contract to a new account. Replaces the pending transfer if there is one.
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual override onlyOwner {
        _pendingOwner = newOwner;
        emit OwnershipTransferStarted(owner(), newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`) and deletes any pending owner.
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual override {
        delete _pendingOwner;
        super._transferOwnership(newOwner);
    }

    /**
     * @dev The new owner accepts the ownership transfer.
     */
    function acceptOwnership() public virtual {
        address sender = _msgSender();
        require(pendingOwner() == sender, "Ownable2Step: caller is not the new owner");
        _transferOwnership(sender);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.7.0 || ^0.8.0;

interface IFxRebalancePoolSplitter {
  /**********
   * Events *
   **********/

  /// @notice Emitted when the address of splitter is updated.
  /// @param token The address of the token.
  /// @param oldSplitter The address of previous token splitter.
  /// @param newSplitter The address of current token splitter.
  event UpdateSplitter(address indexed token, address indexed oldSplitter, address indexed newSplitter);

  /// @notice Emitted when a new receiver is added.
  /// @param token The address of the token.
  /// @param receiver The address of the receiver.
  event RegisterReceiver(address indexed token, address indexed receiver);

  /// @notice Emitted when an exsited receiver is removed.
  /// @param token The address of the token.
  /// @param receiver The address of the receiver.
  event DeregisterReceiver(address indexed token, address indexed receiver);

  /// @notice Emitted when the split ratio is updated.
  /// @param token The address of the token.
  /// @param ratios The list of new split ratios.
  event UpdateSplitRatios(address indexed token, uint256[] ratios);

  /*************************
   * Public View Functions *
   *************************/

  /// @notice Return the splitter of the given token.
  /// @param token The address of token to query.
  function splitter(address token) external view returns (address);

  /// @notice Return the receivers and split ratios for the given token.
  /// @param token The address of token to query.
  /// @return receivers The address list of receivers.
  /// @return ratios The list of corresponding split ratio.
  function getReceivers(address token) external view returns (address[] memory receivers, uint256[] memory ratios);

  /****************************
   * Public Mutated Functions *
   ****************************/

  /// @notice Split token to different RebalancePool.
  /// @param token The address of token to split.
  function split(address token) external;
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";

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

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

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

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);

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

    /**
     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
     * Revert on invalid signature.
     */
    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

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

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
        // and not revert is the subcall reverts.

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

// SPDX-License-Identifier: MIT

pragma solidity =0.8.20;

import { Ownable2Step } from "@openzeppelin/contracts-v4/access/Ownable2Step.sol";
import { IERC20 } from "@openzeppelin/contracts-v4/token/ERC20/IERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts-v4/token/ERC20/utils/SafeERC20.sol";

import { IFxRebalancePoolSplitter } from "../../interfaces/f(x)/IFxRebalancePoolSplitter.sol";
import { IFxTreasury } from "../../interfaces/f(x)/IFxTreasury.sol";
import { ICurveTokenMinter } from "../../interfaces/ICurveTokenMinter.sol";

contract RebalancePoolGaugeClaimer is Ownable2Step {
  using SafeERC20 for IERC20;

  /**********
   * Events *
   **********/

  /// @notice Emitted when the incentive ratio is updated.
  /// @param oldIncentiveRatio The value of previous incentive ratio, multiplied by 1e18.
  /// @param newIncentiveRatio The value of current incentive ratio, multiplied by 1e18.
  event UpdateIncentiveRatio(uint256 oldIncentiveRatio, uint256 newIncentiveRatio);

  /// @notice Emitted when the splitter ratio parameter is updated.
  /// @param leverageRatioLowerBound The current lower bound of leverage ratio, multiplied by 1e18.
  /// @param leverageRatioUpperBound The current upper bound of leverage ratio, multiplied by 1e18.
  /// @param minSplitterRatio The current minimum splitter ratio, multiplied by 1e18.
  event UpdateSplitterRatio(uint256 leverageRatioLowerBound, uint256 leverageRatioUpperBound, uint256 minSplitterRatio);

  /**********
   * Errors *
   **********/

  /// @dev Thrown when the incentive ratio is too large.
  error ErrorIncentiveRatioTooLarge();

  /// @dev Thrown when the leverage ratio lower bound is out of bound.
  error ErrorInvalidLeverageRatioLowerBound();

  /// @dev Thrown when the leverage ratio upper bound is out of bound.
  error ErrorInvalidLeverageRatioUpperBound();

  /// @dev Thrown when the min splitter ratio is out of bound.
  error ErrorInvalidMinSplitRatio();

  /*************
   * Constants *
   *************/

  /// @dev The incentive ratio precision.
  uint256 private constant PRECISION = 1e18;

  /// @dev The maximum value of incentive ratio.
  uint256 private constant MAX_INCENTIVE_RATIO = 1e17; // 10%

  /// @dev The minimum value of `leveratio_raio_min`.
  uint256 private constant MIN_LEVERAGE_RATIO_LOWER_BOUND = 13e17; // 1.3

  /// @dev The maximum value of `leveratio_raio_min`.
  uint256 private constant MAX_LEVERAGE_RATIO_LOWER_BOUND = 2e18; // 2

  /// @dev The minimum value of `leveratio_raio_max`.
  uint256 private constant MIN_LEVERAGE_RATIO_UPPER_BOUND = 2e18; // 2

  /// @dev The maximum value of `leveratio_raio_max`.
  uint256 private constant MAX_LEVERAGE_RATIO_UPPER_BOUND = 5e18; // 5

  /// @dev The minimum value of `splitter_raio_min`.
  uint256 private constant MIN_MINIMUM_SPLITTER_RATIO = 5e17; // 0.5

  /// @dev The maximum value of `splitter_raio_max`.
  uint256 private constant MAX_MINIMUM_SPLITTER_RATIO = 1e18; // 1

  /// @dev The address of FXN token.
  address private constant FXN = 0x365AccFCa291e7D3914637ABf1F7635dB165Bb09;

  /// @dev The address of FXN token minter.
  address private constant TOKEN_MINTER = 0xC8b194925D55d5dE9555AD1db74c149329F71DeF;

  /// @notice The address of FXN reserve pool.
  address public immutable reservePool;

  /// @notice The address of Treasury contract.
  address public immutable treasury;

  /// @notice The address of gauge contract.
  address public immutable gauge;

  /// @notice The address of RebalancePoolSplitter contract.
  address public immutable splitter;

  /***********
   * Structs *
   ***********/

  /// @param leverageRatioLowerBound The lower bound value of leverage ratio.
  /// @param leverageRatioUpperBound The upper bound value of leverage ratio.
  /// @param minSplitterRatio The minimum value of splitter ratio.
  struct SplitterRatioParameters {
    uint64 leverageRatioLowerBound;
    uint64 leverageRatioUpperBound;
    uint64 minSplitterRatio;
  }

  /*************
   * Variables *
   *************/

  /// @notice The parameters used to compute splitter ratio.
  SplitterRatioParameters public params;

  /// @notice The incentive ratio for caller of `claim`.
  uint256 public incentiveRatio;

  /***************
   * Constructor *
   ***************/

  constructor(
    address _reservePool,
    address _treasury,
    address _gauge,
    address _splitter
  ) {
    reservePool = _reservePool;
    treasury = _treasury;
    gauge = _gauge;
    splitter = _splitter;

    _updateSplitterRatioParameters(2 * 10**18, 3 * 10**18, 666666666666666666);
    _updateIncentiveRatio(10**16);
  }

  /*************************
   * Public View Functions *
   *************************/

  /// @notice Compute the current splitter ratio, multiplied by 1e18.
  function getSplitterRatio() external view returns (uint256) {
    return _computeSplitterRatio();
  }

  /****************************
   * Public Mutated Functions *
   ****************************/

  /// @notice Claim pending FXN from gauge and split to rebalance pools.
  /// @param _receiver The address of incentive receiver.
  function claim(address _receiver) external {
    unchecked {
      // @note We allow donating FXN to this contract, the incentive should only consider minted FXN.
      uint256 _balance = IERC20(FXN).balanceOf(address(this));
      ICurveTokenMinter(TOKEN_MINTER).mint(gauge);
      uint256 _minted = IERC20(FXN).balanceOf(address(this)) - _balance;
      uint256 _incentive = (_minted * incentiveRatio) / PRECISION;
      _balance += _minted;

      if (_incentive > 0) {
        IERC20(FXN).safeTransfer(_receiver, _incentive);
        _balance -= _incentive;
      }

      if (_balance > 0) {
        uint256 _ratio = _computeSplitterRatio();
        uint256 _splitterFXN = (_balance * _ratio) / PRECISION;
        // deposit rewards to rebalance pool splitter
        IERC20(FXN).safeTransfer(splitter, _splitterFXN);
        // transfer extra FXN to reserve pool
        IERC20(FXN).safeTransfer(reservePool, _balance - _splitterFXN);
        // split rewards
        IFxRebalancePoolSplitter(splitter).split(FXN);
      }
    }
  }

  /************************
   * Restricted Functions *
   ************************/

  /// @notice Update the incentive ratio.
  /// @param _newIncentiveRatio The new incentive ratio to claim caller, multiplied by 1e18.
  function updateIncentiveRatio(uint256 _newIncentiveRatio) external onlyOwner {
    _updateIncentiveRatio(_newIncentiveRatio);
  }

  /// @notice Update the splitter ratio parameters.
  /// @param _minLeverage The minimum leverage ratio, multiplied by 1e18.
  /// @param _maxLeverage The maximum leverage ratio, multiplied by 1e18.
  /// @param _minRatio The minimum splitter ratio, multiplied by 1e18.
  function updateSplitterRatioParameters(
    uint64 _minLeverage,
    uint64 _maxLeverage,
    uint64 _minRatio
  ) external onlyOwner {
    _updateSplitterRatioParameters(_minLeverage, _maxLeverage, _minRatio);
  }

  /************************
   * Internal Functions *
   ************************/

  /// @dev Internal function to compute current splitter ratio.
  /// @return _splitterRatio The current splitter ratio, multiplied by 1e18.
  function _computeSplitterRatio() internal view returns (uint256 _splitterRatio) {
    SplitterRatioParameters memory _params = params;
    uint256 _leverageRatio = IFxTreasury(treasury).leverageRatio();
    if (_leverageRatio > _params.leverageRatioUpperBound) {
      _splitterRatio = _params.minSplitterRatio;
    } else if (_leverageRatio < _params.leverageRatioLowerBound) {
      _splitterRatio = PRECISION;
    } else {
      // a = (leverageRatioLowerBound * minSplitterRatio - leverageRatioUpperBound) / c
      // b = (1 - minSplitterRatio) / c
      // c = leverageRatioLowerBound - leverageRatioUpperBound
      // a + b * leverageRatio
      //   = leverageRatioLowerBound * minSplitterRatio - leverageRatioUpperBound + (1 - minSplitterRatio) * leverageRatio
      //   = minSplitterRatio * (leverageRatioLowerBound - leverageRatio) + leverageRatio - leverageRatioUpperBound
      unchecked {
        _splitterRatio =
          (uint256(_params.minSplitterRatio) *
            (_leverageRatio - uint256(_params.leverageRatioLowerBound)) +
            (uint256(_params.leverageRatioUpperBound) - _leverageRatio) *
            PRECISION) /
          uint256(_params.leverageRatioUpperBound - _params.leverageRatioLowerBound);
      }
    }
  }

  /// @dev Internal function to update the incentive ratio.
  /// @param _newIncentiveRatio The new incentive ratio to claim caller, multiplied by 1e18.
  function _updateIncentiveRatio(uint256 _newIncentiveRatio) internal {
    if (_newIncentiveRatio > MAX_INCENTIVE_RATIO) {
      revert ErrorIncentiveRatioTooLarge();
    }

    uint256 _oldIncentiveRatio = incentiveRatio;
    incentiveRatio = _newIncentiveRatio;

    emit UpdateIncentiveRatio(_oldIncentiveRatio, _newIncentiveRatio);
  }

  /// @dev Internal function to update the splitter ratio parameters.
  /// @param _leverageRatioLowerBound The lower bound of leverage ratio, multiplied by 1e18.
  /// @param _leverageRatioUpperBound The upper bound of leverage ratio, multiplied by 1e18.
  /// @param _minSplitterRatio The minimum splitter ratio, multiplied by 1e18.
  function _updateSplitterRatioParameters(
    uint64 _leverageRatioLowerBound,
    uint64 _leverageRatioUpperBound,
    uint64 _minSplitterRatio
  ) internal {
    if (
      _leverageRatioLowerBound < MIN_LEVERAGE_RATIO_LOWER_BOUND ||
      _leverageRatioLowerBound > MAX_LEVERAGE_RATIO_LOWER_BOUND
    ) {
      revert ErrorInvalidLeverageRatioLowerBound();
    }
    if (
      _leverageRatioUpperBound < MIN_LEVERAGE_RATIO_UPPER_BOUND ||
      _leverageRatioUpperBound > MAX_LEVERAGE_RATIO_UPPER_BOUND
    ) {
      revert ErrorInvalidLeverageRatioUpperBound();
    }
    if (_minSplitterRatio < MIN_MINIMUM_SPLITTER_RATIO || _minSplitterRatio > MAX_MINIMUM_SPLITTER_RATIO) {
      revert ErrorInvalidMinSplitRatio();
    }

    params = SplitterRatioParameters(_leverageRatioLowerBound, _leverageRatioUpperBound, _minSplitterRatio);

    emit UpdateSplitterRatio(_leverageRatioLowerBound, _leverageRatioUpperBound, _minSplitterRatio);
  }
}

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

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
 * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
 *
 * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
 * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
 * need to send a transaction, and thus is not required to hold Ether at all.
 */
interface IERC20Permit {
    /**
     * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
     * given ``owner``'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

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

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