// File: contracts/utils/STETHDepositHelper.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.4;

import {ICurveETHSTETHPool} from "../interfaces/ICurveETHSTETHPool.sol";
import {IRibbonThetaVault} from "../interfaces/IRibbonThetaVault.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {
    SafeERC20
} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

contract STETHDepositHelper {
    using SafeERC20 for IERC20;

    ICurveETHSTETHPool public immutable curveETHSTETHPool;
    IRibbonThetaVault public immutable stETHVault;
    IERC20 public immutable stETH;

    constructor(
        address _curveETHSTETHPool,
        address _stETHVault,
        address _stETH
    ) {
        require(_curveETHSTETHPool != address(0), "!curveETHSTETH Pool");
        require(_stETHVault != address(0), "!stETHVault");
        require(_stETH != address(0), "!_stETH");

        curveETHSTETHPool = ICurveETHSTETHPool(_curveETHSTETHPool);
        stETHVault = IRibbonThetaVault(_stETHVault);
        stETH = IERC20(_stETH);
    }

    /**
     * Swaps ETH -> stETH on Curve ETH-stETH pool, and deposits into stETH vault
     */
    function deposit(uint256 minSTETHAmount) external payable {
        curveETHSTETHPool.exchange{value: msg.value}(
            0,
            1,
            msg.value,
            minSTETHAmount
        );
        uint256 balance = stETH.balanceOf(address(this));
        stETH.safeApprove(address(stETHVault), balance);
        stETHVault.depositYieldTokenFor(balance, msg.sender);
    }
}

// File: contracts/interfaces/ICurveETHSTETHPool.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface ICurveETHSTETHPool {
    function get_dy(
        int128 i,
        int128 j,
        uint256 dx
    ) external view returns (uint256);

    function exchange(
        int128 i,
        int128 j,
        uint256 dx,
        uint256 min_dy
    ) external payable returns (uint256);
}

// File: contracts/interfaces/IRibbonThetaVault.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.4;

import {Vault} from "../libraries/Vault.sol";

interface IRibbonThetaVault {
    function currentOption() external view returns (address);

    function nextOption() external view returns (address);

    function vaultParams() external view returns (Vault.VaultParams memory);

    function vaultState() external view returns (Vault.VaultState memory);

    function optionState() external view returns (Vault.OptionState memory);

    function optionAuctionID() external view returns (uint256);

    function pricePerShare() external view returns (uint256);

    function roundPricePerShare(uint256) external view returns (uint256);

    function depositFor(uint256 amount, address creditor) external;

    function initiateWithdraw(uint256 numShares) external;

    function completeWithdraw() external;

    function maxRedeem() external;

    function depositYieldTokenFor(uint256 amount, address creditor) external;

    function symbol() external view returns (string calldata);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @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);
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC20.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;

    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'
        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
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}

// File: contracts/libraries/Vault.sol



// SPDX-License-Identifier: MIT
pragma solidity =0.8.4;

library Vault {
    /************************************************
     *  IMMUTABLES & CONSTANTS
     ***********************************************/

    // Fees are 6-decimal places. For example: 20 * 10**6 = 20%
    uint256 internal constant FEE_MULTIPLIER = 10**6;

    // Premium discount has 1-decimal place. For example: 80 * 10**1 = 80%. Which represents a 20% discount.
    uint256 internal constant PREMIUM_DISCOUNT_MULTIPLIER = 10;

    // Otokens have 8 decimal places.
    uint256 internal constant OTOKEN_DECIMALS = 8;

    // Percentage of funds allocated to options is 2 decimal places. 10 * 10**2 = 10%
    uint256 internal constant OPTION_ALLOCATION_MULTIPLIER = 10**2;

    // Placeholder uint value to prevent cold writes
    uint256 internal constant PLACEHOLDER_UINT = 1;

    struct VaultParams {
        // Option type the vault is selling
        bool isPut;
        // Token decimals for vault shares
        uint8 decimals;
        // Asset used in Theta / Delta Vault
        address asset;
        // Underlying asset of the options sold by vault
        address underlying;
        // Minimum supply of the vault shares issued, for ETH it's 10**10
        uint56 minimumSupply;
        // Vault cap
        uint104 cap;
    }

    struct OptionState {
        // Option that the vault is shorting / longing in the next cycle
        address nextOption;
        // Option that the vault is currently shorting / longing
        address currentOption;
        // The timestamp when the `nextOption` can be used by the vault
        uint32 nextOptionReadyAt;
    }

    struct VaultState {
        // 32 byte slot 1
        //  Current round number. `round` represents the number of `period`s elapsed.
        uint16 round;
        // Amount that is currently locked for selling options
        uint104 lockedAmount;
        // Amount that was locked for selling options in the previous round
        // used for calculating performance fee deduction
        uint104 lastLockedAmount;
        // 32 byte slot 2
        // Stores the total tally of how much of `asset` there is
        // to be used to mint rTHETA tokens
        uint128 totalPending;
        // Total amount of queued withdrawal shares from previous rounds (doesn't include the current round)
        uint128 queuedWithdrawShares;
    }

    struct DepositReceipt {
        // Maximum of 65535 rounds. Assuming 1 round is 7 days, maximum is 1256 years.
        uint16 round;
        // Deposit amount, max 20,282,409,603,651 or 20 trillion ETH deposit
        uint104 amount;
        // Unredeemed shares balance
        uint128 unredeemedShares;
    }

    struct Withdrawal {
        // Maximum of 65535 rounds. Assuming 1 round is 7 days, maximum is 1256 years.
        uint16 round;
        // Number of shares withdrawn
        uint128 shares;
    }

    struct AuctionSellOrder {
        // Amount of `asset` token offered in auction
        uint96 sellAmount;
        // Amount of oToken requested in auction
        uint96 buyAmount;
        // User Id of delta vault in latest gnosis auction
        uint64 userId;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @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;
        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");

        (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");

        (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");

        (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");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason 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 {
            // 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

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}