/**
 * Tracks the active 6-digit pairing-server session.
 *
 * While a token is active, `setupIncomingPairingSubscriber` auto-accepts the
 * first PAIR_REQUEST that arrives (the user's act of showing the code is the
 * consent — no banner). The token expires after `expiresAt` so a stale
 * pairing window cannot silently accept a peer minutes later.
 *
 * On a successful pairing while the popup is closed, the responder records a
 * `RecentPairing` so the next popup open can flash a "Paired with X"
 * confirmation. The record is read-once.
 */

const ACTIVE_TOKEN_KEY = "peach_active_pairing_token";
const RECENT_PAIRING_KEY = "peach_recent_pairing";

export interface ActivePairingToken {
  token: string;
  expiresAt: number;
}

export interface RecentPairing {
  deviceName: string;
  pairedAt: number;
  /** "showing" — we showed the code; "entering" — we typed a code. */
  side: "showing" | "entering";
}

export async function setActivePairingToken(value: ActivePairingToken | null): Promise<void> {
  try {
    if (value === null) {
      await chrome.storage.session.remove(ACTIVE_TOKEN_KEY);
    } else {
      await chrome.storage.session.set({ [ACTIVE_TOKEN_KEY]: value });
    }
  } catch {
    // session storage may be unavailable in test contexts
  }
}

export async function getActivePairingToken(): Promise<ActivePairingToken | null> {
  try {
    const result = await chrome.storage.session.get(ACTIVE_TOKEN_KEY);
    const value = (result as Record<string, ActivePairingToken | undefined>)[ACTIVE_TOKEN_KEY];
    if (!value) return null;
    if (Date.now() >= value.expiresAt) {
      await chrome.storage.session.remove(ACTIVE_TOKEN_KEY);
      return null;
    }
    return value;
  } catch {
    return null;
  }
}

export async function setRecentPairing(value: RecentPairing): Promise<void> {
  try {
    await chrome.storage.session.set({ [RECENT_PAIRING_KEY]: value });
  } catch {
    // best-effort
  }
}

export async function consumeRecentPairing(): Promise<RecentPairing | null> {
  try {
    const result = await chrome.storage.session.get(RECENT_PAIRING_KEY);
    const value = (result as Record<string, RecentPairing | undefined>)[RECENT_PAIRING_KEY];
    if (!value) return null;
    await chrome.storage.session.remove(RECENT_PAIRING_KEY);
    return value;
  } catch {
    return null;
  }
}