// SPDX-License-Identifier: MIT

pragma solidity 0.8.9;



// Part: ICurveV2Pool

interface ICurveV2Pool {
    function get_dy(
        uint256 i,
        uint256 j,
        uint256 dx
    ) external view returns (uint256);

    function calc_token_amount(uint256[2] calldata amounts)
        external
        view
        returns (uint256);

    function exchange_underlying(
        uint256 i,
        uint256 j,
        uint256 dx,
        uint256 min_dy
    ) external payable returns (uint256);

    function add_liquidity(uint256[2] calldata amounts, uint256 min_mint_amount)
        external
        returns (uint256);

    function lp_price() external view returns (uint256);

    function price_oracle() external view returns (uint256);

    function remove_liquidity_one_coin(
        uint256 token_amount,
        uint256 i,
        uint256 min_amount,
        bool use_eth,
        address receiver
    ) external returns (uint256);
}

// Part: IGenericVault

interface IGenericVault {
    function withdraw(address _to, uint256 _shares)
        external
        returns (uint256 withdrawn);

    function withdrawAll(address _to) external returns (uint256 withdrawn);

    function depositAll(address _to) external returns (uint256 _shares);

    function deposit(address _to, uint256 _amount)
        external
        returns (uint256 _shares);

    function harvest() external;

    function balanceOfUnderlying(address user)
        external
        view
        returns (uint256 amount);

    function totalUnderlying() external view returns (uint256 total);

    function totalSupply() external view returns (uint256 total);

    function underlying() external view returns (address);

    function strategy() external view returns (address);

    function platform() external view returns (address);

    function setPlatform(address _platform) external;

    function setPlatformFee(uint256 _fee) external;

    function setCallIncentive(uint256 _incentive) external;

    function setWithdrawalPenalty(uint256 _penalty) external;

    function setApprovals() external;

    function callIncentive() external view returns (uint256);

    function platformFee() external view returns (uint256);
}

// Part: IVaultZaps

interface IVaultZaps {
    function depositFromUnderlyingAssets(
        uint256[2] calldata amounts,
        uint256 minAmountOut,
        address to
    ) external;
}

// Part: OpenZeppelin/openzeppelin-contracts@4.1.0/Address

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 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://diligence.consensys.net/posts/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");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (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 functionCall(target, data, "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");
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: value }(data);
        return _verifyCallResult(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) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(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) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
        if (success) {
            return returndata;
        } else {
            // 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

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// Part: OpenZeppelin/openzeppelin-contracts@4.1.0/IERC20

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

    /**
     * @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);
}

// Part: OpenZeppelin/openzeppelin-contracts@4.1.0/MerkleProof

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
        bytes32 computedHash = leaf;

        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];

            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
            }
        }

        // Check if the computed hash (root) is equal to the provided root
        return computedHash == root;
    }
}

// Part: OpenZeppelin/openzeppelin-contracts@4.1.0/SafeERC20

/**
 * @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;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    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'
        // solhint-disable-next-line max-line-length
        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));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    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");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @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");
        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// Part: GenericDistributor

// Allows anyone to claim a token if they exist in a merkle root.
contract GenericDistributor {
    using SafeERC20 for IERC20;

    address public vault;
    address public token;
    bytes32 public merkleRoot;
    uint32 public week;
    bool public frozen;

    address public admin;
    address public depositor;

    // This is a packed array of booleans.
    mapping(uint256 => mapping(uint256 => uint256)) private claimedBitMap;

    // This event is triggered whenever a call to #claim succeeds.
    event Claimed(
        uint256 index,
        uint256 indexed amount,
        address indexed account,
        uint256 week
    );
    // This event is triggered whenever the merkle root gets updated.
    event MerkleRootUpdated(bytes32 indexed merkleRoot, uint32 indexed week);
    // This event is triggered whenever the admin is updated.
    event AdminUpdated(address indexed oldAdmin, address indexed newAdmin);
    // This event is triggered whenever the depositor contract is updated.
    event DepositorUpdated(
        address indexed oldDepositor,
        address indexed newDepositor
    );
    // This event is triggered whenever the vault contract is updated.
    event VaultUpdated(address indexed oldVault, address indexed newVault);
    // When recovering stuck ERC20s
    event Recovered(address token, uint256 amount);

    constructor(
        address _vault,
        address _depositor,
        address _token
    ) {
        require(_vault != address(0));
        vault = _vault;
        admin = msg.sender;
        depositor = _depositor;
        token = _token;
        week = 0;
        frozen = true;
    }

    /// @notice Set approvals for the tokens used when swapping
    function setApprovals() external virtual onlyAdmin {
        IERC20(token).safeApprove(vault, 0);
        IERC20(token).safeApprove(vault, type(uint256).max);
    }

    /// @notice Check if the index has been marked as claimed.
    /// @param index - the index to check
    /// @return true if index has been marked as claimed.
    function isClaimed(uint256 index) public view returns (bool) {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        uint256 claimedWord = claimedBitMap[week][claimedWordIndex];
        uint256 mask = (1 << claimedBitIndex);
        return claimedWord & mask == mask;
    }

    function _setClaimed(uint256 index) private {
        uint256 claimedWordIndex = index / 256;
        uint256 claimedBitIndex = index % 256;
        claimedBitMap[week][claimedWordIndex] =
            claimedBitMap[week][claimedWordIndex] |
            (1 << claimedBitIndex);
    }

    /// @notice Transfers ownership of the contract
    /// @param newAdmin - address of the new admin of the contract
    function updateAdmin(address newAdmin)
        external
        onlyAdmin
        notToZeroAddress(newAdmin)
    {
        address oldAdmin = admin;
        admin = newAdmin;
        emit AdminUpdated(oldAdmin, newAdmin);
    }

    /// @notice Changes the contract allowed to freeze before depositing
    /// @param newDepositor - address of the new depositor contract
    function updateDepositor(address newDepositor)
        external
        onlyAdmin
        notToZeroAddress(newDepositor)
    {
        address oldDepositor = depositor;
        depositor = newDepositor;
        emit DepositorUpdated(oldDepositor, newDepositor);
    }

    /// @notice Changes the Vault where funds are staked
    /// @param newVault - address of the new vault contract
    function updateVault(address newVault)
        external
        onlyAdmin
        notToZeroAddress(newVault)
    {
        address oldVault = vault;
        vault = newVault;
        emit VaultUpdated(oldVault, newVault);
    }

    /// @notice Internal function to handle users' claims
    /// @param index - claimer index
    /// @param account - claimer account
    /// @param amount - claim amount
    /// @param merkleProof - merkle proof for the claim
    function _claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) internal {
        require(!frozen, "Claiming is frozen.");
        require(!isClaimed(index), "Drop already claimed.");

        // Verify the merkle proof.
        bytes32 node = keccak256(abi.encodePacked(index, account, amount));
        require(
            MerkleProof.verify(merkleProof, merkleRoot, node),
            "Invalid proof."
        );

        // Mark it claimed and send the token.
        _setClaimed(index);
    }

    /// @notice Claim the given amount of uCRV to the given address.
    /// @param index - claimer index
    /// @param account - claimer account
    /// @param amount - claim amount
    /// @param merkleProof - merkle proof for the claim
    function claim(
        uint256 index,
        address account,
        uint256 amount,
        bytes32[] calldata merkleProof
    ) external {
        // Claim
        _claim(index, account, amount, merkleProof);

        // Send shares to account
        IERC20(vault).safeTransfer(account, amount);

        emit Claimed(index, amount, account, week);
    }

    /// @notice Stakes the contract's entire balance in the Vault
    function stake() external virtual onlyAdminOrDistributor {
        IGenericVault(vault).depositAll(address(this));
    }

    /// @notice Freezes the claim function to allow the merkleRoot to be changed
    /// @dev Can be called by the owner or the depositor zap contract
    function freeze() external onlyAdminOrDistributor {
        frozen = true;
    }

    /// @notice Unfreezes the claim function.
    function unfreeze() public onlyAdmin {
        frozen = false;
    }

    /// @notice Update the merkle root and increment the week.
    /// @param _merkleRoot - the new root to push
    /// @param _unfreeze - whether to unfreeze the contract after unlock
    function updateMerkleRoot(bytes32 _merkleRoot, bool _unfreeze)
        external
        onlyAdmin
    {
        require(frozen, "Contract not frozen.");

        // Increment the week (simulates the clearing of the claimedBitMap)
        week = week + 1;
        // Set the new merkle root
        merkleRoot = _merkleRoot;

        emit MerkleRootUpdated(merkleRoot, week);

        if (_unfreeze) {
            unfreeze();
        }
    }

    /// @notice Recover ERC20s mistakenly sent to the contract
    /// @param tokenAddress - address of the token to retrieve
    /// @param tokenAmount - amount to retrieve
    /// @dev Will revert if token is same as token being distributed
    function recoverERC20(address tokenAddress, uint256 tokenAmount)
        external
        onlyAdmin
    {
        require(
            tokenAddress != address(token),
            "Cannot withdraw the distributed token"
        );
        IERC20(tokenAddress).safeTransfer(msg.sender, tokenAmount);
        emit Recovered(tokenAddress, tokenAmount);
    }

    receive() external payable {}

    modifier onlyAdmin() {
        require(msg.sender == admin, "Admin only");
        _;
    }

    modifier onlyAdminOrDistributor() {
        require(
            (msg.sender == admin) || (msg.sender == depositor),
            "Admin or depositor only"
        );
        _;
    }

    modifier notToZeroAddress(address _to) {
        require(_to != address(0), "Invalid address!");
        _;
    }
}

// File: FXSDistributor.sol

contract FXSMerkleDistributor is GenericDistributor {
    using SafeERC20 for IERC20;

    address public vaultZap;

    address private constant FXS_TOKEN =
        0x3432B6A60D23Ca0dFCa7761B7ab56459D9C964D0;

    address private constant CURVE_CVXFXS_FXS_POOL =
        0xd658A338613198204DCa1143Ac3F01A722b5d94A;
    address private constant CURVE_FXS_ETH_POOL =
        0x941Eb6F616114e4Ecaa85377945EA306002612FE;

    // 2.5% slippage tolerance by default
    uint256 public slippage = 9750;
    uint256 private constant DECIMALS = 10000;

    ICurveV2Pool private cvxFxsPool = ICurveV2Pool(CURVE_CVXFXS_FXS_POOL);
    ICurveV2Pool private ethFxsPool = ICurveV2Pool(CURVE_FXS_ETH_POOL);

    // This event is triggered whenever the zap contract is updated.
    event ZapUpdated(address indexed oldZap, address indexed newZap);

    constructor(
        address _vault,
        address _depositor,
        address _zap
    ) GenericDistributor(_vault, _depositor, FXS_TOKEN) {
        require(_zap != address(0));
        vaultZap = _zap;
    }

    /// @notice Changes the Zap for deposits
    /// @param newZap - address of the new zap
    function updateZap(address newZap)
        external
        onlyAdmin
        notToZeroAddress(newZap)
    {
        address oldZap = vaultZap;
        vaultZap = newZap;
        emit ZapUpdated(oldZap, vaultZap);
    }

    /// @notice Set approvals for the tokens used when swapping
    function setApprovals() external override onlyAdmin {
        IERC20(token).safeApprove(vaultZap, 0);
        IERC20(token).safeApprove(vaultZap, type(uint256).max);
    }

    /// @notice Set the acceptable level of slippage for LP deposits
    /// @dev As percentage of the ETH value of original amount in BIPS
    /// @param _slippage - the acceptable slippage threshold
    function setSlippage(uint256 _slippage) external onlyAdmin {
        slippage = _slippage;
    }

    /// @notice Calculates the minimum amount of LP tokens we want to receive
    /// @dev Uses Curve's estimation of received LP tokens & price oracles
    /// @param _amount - the amount of FXS tokens to deposit
    /// @return a min amount we can use to guarantee < x% slippage
    function _calcLPMinAmountOut(uint256 _amount) internal returns (uint256) {
        uint256 _receivedLPTokens = (cvxFxsPool.calc_token_amount(
            [_amount, 0]
        ) * 9900) / DECIMALS;
        uint256 _lpTokenFxsPrice = (_receivedLPTokens * cvxFxsPool.lp_price()) /
            1e18;
        uint256 _fxsEthPrice = ethFxsPool.price_oracle();
        uint256 _lpTokenEthPrice = (_lpTokenFxsPrice * _fxsEthPrice) / 1e18;
        uint256 _amountEthPrice = (_amount * _fxsEthPrice) / 1e18;
        // ensure we're not getting more than x% slippage on ETH value
        require(
            _lpTokenEthPrice > ((_amountEthPrice * slippage) / DECIMALS),
            "slippage"
        );
        return _receivedLPTokens;
    }

    /// @notice Stakes the contract's entire cvxCRV balance in the Vault
    function stake() external override onlyAdminOrDistributor {
        uint256 _balance = IERC20(FXS_TOKEN).balanceOf(address(this));
        IVaultZaps(vaultZap).depositFromUnderlyingAssets(
            [_balance, 0],
            _calcLPMinAmountOut(_balance),
            address(this)
        );
    }
}