# PartyB Quote Actions

The PartyB Quote Actions Facet handles PartyB's interactions with quotes before a position is opened — locking quotes, unlocking them, and accepting cancellation requests. These are the first steps in the quote lifecycle after PartyA sends a quote. The underlying logic is implemented in the `PartyBQuoteActionsFacetImpl` library.

When PartyA has activated instant action mode, these functions are typically called through the Instant Layer rather than directly. In the Instant Layer flow, `lockQuote` is commonly part of a `sendQuote` → `lockQuote` → `openPosition` template that executes all three steps in a single transaction using signed operations.

***

### Overview

The PartyB Quote Actions Facet provides the following key functionalities:

* **Lock Quote:** PartyB secures a pending quote by locking it, reserving the required margin from their allocated balance. Once locked, no other PartyB can act on the quote.
* **Unlock Quote:** PartyB releases a previously locked quote, returning it to pending status (or expiring it if past deadline) so other PartyBs can secure it.
* **Accept Cancel Request:** PartyB accepts PartyA's cancellation request for a locked quote, releasing it back to cancelled status.

***

### lockQuote()

Locks a pending quote, securing it for this PartyB. Once locked, the quote is reserved exclusively for this PartyB to open a position. The required margin (based on PartyB's estimated PnL from the position) is reserved from PartyB's allocated balance. A Muon `SingleUpnlSig` is required to verify PartyB remains solvent after locking.

Any whitelisted PartyB can lock the quote (or any PartyB if no whitelist was set on the quote).

**Function Signature:**

```solidity
function lockQuote(uint256 quoteId, SingleUpnlSig memory upnlSig) external whenNotPartyBOpenPositionsPaused onlyPartyB notLiquidated(quoteId);
```

**Parameters:**

* `quoteId`: The ID of the quote to lock.
* `upnlSig`: The Muon signature containing PartyB's uPnL for solvency verification.

**Access:** Only callable by a registered PartyB. Neither party can be in liquidation.

**Events Emitted:**

* `LockQuote(address partyB, uint256 quoteId)`

***

### unlockQuote()

Releases a previously locked quote. If the quote's deadline has passed, it is expired. Otherwise, it returns to `PENDING` status, allowing other PartyBs to lock it.

**Function Signature:**

```solidity
function unlockQuote(uint256 quoteId) external whenNotPartyBActionsPaused onlyPartyBOfQuote(quoteId) notLiquidated(quoteId);
```

**Parameters:**

* `quoteId`: The ID of the quote to unlock.

**Access:** Only callable by the PartyB who locked the quote. Neither party can be in liquidation.

**Events Emitted:**

* `UnlockQuote(address partyB, uint256 quoteId, QuoteStatus status)` — when the quote returns to `PENDING`
* `ExpireQuoteOpen(QuoteStatus status, uint256 quoteId)` — when the quote has expired

***

### acceptCancelRequest()

Accepts PartyA's cancellation request for a locked quote. The quote enters `CANCELED` status and the reserved margin is released back to both parties.

This is called when a quote is in `CANCEL_PENDING` status — meaning PartyA requested cancellation after PartyB had already locked the quote, and PartyB agrees to release it.

**Function Signature:**

```solidity
function acceptCancelRequest(uint256 quoteId) external whenNotPartyBActionsPaused onlyPartyBOfQuote(quoteId) notLiquidated(quoteId);
```

**Parameters:**

* `quoteId`: The ID of the quote whose cancellation request should be accepted.

**Access:** Only callable by the PartyB of the quote. Neither party can be in liquidation.

**Events Emitted:**

* `AcceptCancelRequest(uint256 quoteId, QuoteStatus status)`