// File: contracts/PerpetualFuturesUnsettledHandler.sol



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

import '@openzeppelin/contracts/utils/Context.sol';
import '@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol';
import './interfaces/IPerpetualFutures.sol';

contract PerpetualFuturesUnsettledHandler is Context {
  IPerpetualFutures public perpetualFutures;

  struct UnsettledPositions {
    uint256 tokenId;
    address owner;
    address collateralToken;
    uint256 unsettledAmount;
  }

  UnsettledPositions[] public unsettled;

  event AddUnsettledPosition(
    uint256 indexed tokenId,
    address indexed token,
    uint256 amount,
    uint256 idx
  );
  event SettlePosition(
    uint256 indexed tokenId,
    uint256 collateralAmount,
    uint256 mainAmount,
    uint256 collateralPriceUSD,
    uint256 mainPriceUSD
  );

  modifier onlyPerps() {
    require(_msgSender() == address(perpetualFutures), 'UNAUTHORIZED');
    _;
  }

  modifier onlyRelay() {
    require(perpetualFutures.relays(_msgSender()), 'UNAUTHORIZED');
    _;
  }

  constructor() {
    perpetualFutures = IPerpetualFutures(_msgSender());
  }

  function getAllUnsettled()
    external
    view
    returns (UnsettledPositions[] memory)
  {
    return unsettled;
  }

  function getUnsettledLength() external view returns (uint256) {
    return unsettled.length;
  }

  function addUnsettledPosition(
    uint256 _tokenId,
    address _ownerAtAddTime,
    address _token,
    uint256 _amount
  ) external onlyPerps {
    unsettled.push(
      UnsettledPositions({
        tokenId: _tokenId,
        owner: _ownerAtAddTime,
        collateralToken: _token,
        unsettledAmount: _amount
      })
    );
    emit AddUnsettledPosition(_tokenId, _token, _amount, unsettled.length - 1);
  }

  function settleUnsettledPosition(
    uint256 _idx,
    uint256 _collPriceUSD,
    uint256 _mainPriceUSD
  ) external onlyRelay {
    UnsettledPositions memory _info = unsettled[_idx];
    uint256 _mainSettleAmt = (_info.unsettledAmount *
      10**IERC20Metadata(perpetualFutures.mainCollateralToken()).decimals() *
      _collPriceUSD) /
      _mainPriceUSD /
      10**IERC20Metadata(_info.collateralToken).decimals();
    perpetualFutures.executeSettlement(
      _info.tokenId,
      _info.owner,
      _mainSettleAmt
    );
    unsettled[_idx] = unsettled[unsettled.length - 1];
    unsettled.pop();
    emit SettlePosition(
      _info.tokenId,
      _info.unsettledAmount,
      _mainSettleAmt,
      _collPriceUSD,
      _mainPriceUSD
    );
  }
}

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



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

pragma solidity ^0.8.0;

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

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

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



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

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: contracts/interfaces/IPerpetualFutures.sol



import '@openzeppelin/contracts/token/ERC721/IERC721.sol';

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

interface IPerpetualFutures {
  struct Index {
    string name;
    uint256 dowOpenMin;
    uint256 dowOpenMax;
    uint256 hourOpenMin;
    uint256 hourOpenMax;
    bool isActive;
  }

  struct PositionLifecycle {
    uint256 openTime;
    uint256 openFees;
    uint256 closeTime;
    uint256 closeFees;
    uint256 settleCollPriceUSD; // For positions with alternate collateral, USD per collateral token extended to 18 decimals
    uint256 settleMainPriceUSD; // For positions with alternate collateral, USD per main token extended to 18 decimals
  }

  struct Position {
    PositionLifecycle lifecycle;
    uint256 indexIdx;
    address collateralToken;
    uint256 collateralAmount;
    bool isLong;
    uint16 leverage;
    uint256 indexPriceStart;
    uint256 indexPriceSettle;
    uint256 amountWon;
    uint256 amountLost;
    bool isSettled;
    uint256 mainCollateralSettledAmount;
  }

  struct ActionRequest {
    uint256 timestamp;
    address requester;
    uint256 indexIdx;
    uint256 tokenId;
    address owner;
    address collateralToken;
    uint256 collateralAmount;
    bool isLong;
    uint16 leverage;
    uint256 openSlippage;
    uint256 desiredIdxPriceStart;
  }

  function openFeeETH() external view returns (uint256);

  function mainCollateralToken() external view returns (address);

  function relays(address wallet) external view returns (bool);

  function perpsNft() external view returns (IERC721);

  function positions(uint256 tokenId) external view returns (Position memory);

  function openPositionRequest(
    address collateralToken,
    uint256 indexInd,
    uint256 desiredPrice,
    uint256 slippage,
    uint256 collateral,
    uint16 leverage,
    bool isLong,
    uint256 tokenId, // optional: if adding margin
    address owner // optional: if opening for another wallet
  ) external payable;

  function executeSettlement(
    uint256 tokenId,
    address to,
    uint256 amount
  ) external;
}

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



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

pragma solidity ^0.8.0;

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

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

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

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

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

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

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

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

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}