'use client';

// v1.1.0 (ISS-107) — client-side session handling shared by every authenticated fetcher, the
// sign-in screen and the admin panel. The server mints sessions at /api/login + /api/register;
// we only store the id in localStorage and echo it back as X-Flight-Session.

export const SESSION_STORAGE_KEY = 'flight.session';

export function storedSession(): string | null {
  if (typeof window === 'undefined') return null;
  try {
    return window.localStorage.getItem(SESSION_STORAGE_KEY);
  } catch {
    return null; // storage blocked (private mode) — treat as signed out
  }
}

// Headers for an authenticated fetch. Empty object when no session is stored, so callers can
// spread it into their existing header objects without branching.
export function sessionHeaders(session: string | null = storedSession()): Record<string, string> {
  return session ? { 'X-Flight-Session': session } : {};
}

export function storeSession(sessionId: string): void {
  window.localStorage.setItem(SESSION_STORAGE_KEY, sessionId);
}

export function clearStoredSession(): void {
  try {
    window.localStorage.removeItem(SESSION_STORAGE_KEY);
  } catch {
    // storage blocked — nothing to clear
  }
}