// Aura Cloud Service Worker — High-Performance Offline & Shell Cache v2.0
const CACHE_NAME = 'aura-cloud-pwa-v3';

const STATIC_PRECACHE = [
  '/',
  '/index.html',
  '/manifest.json',
  '/logo.png',
  '/apple-touch-icon.png',
  '/icon-192.png',
  '/icon-512.png',
  '/icon-maskable-192.png',
  '/icon-maskable-512.png',
  '/privacy.html',
  '/terms.html'
];

self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      return cache.addAll(STATIC_PRECACHE).catch((err) => {
        console.warn('[Aura PWA SW] Pre-cache initial warning:', err);
      });
    }).then(() => self.skipWaiting())
  );
});

self.addEventListener('activate', (event) => {
  event.waitUntil(
    caches.keys().then((keys) => {
      return Promise.all(
        keys.filter((k) => k !== CACHE_NAME).map((k) => caches.delete(k))
      );
    }).then(() => self.clients.claim())
  );
});

self.addEventListener('fetch', (event) => {
  const req = event.request;
  const url = new URL(req.url);

  // 1. Bypass external/cross-origin requests (Auth, Analytics, Fonts, APIs)
  if (url.origin !== self.location.origin) {
    return;
  }

  // 2. Network-first strategy for navigation / HTML routes (instant updates)
  if (req.mode === 'navigate' || req.headers.get('accept')?.includes('text/html')) {
    event.respondWith(
      fetch(req)
        .then((networkRes) => {
          if (networkRes && networkRes.ok) {
            const clone = networkRes.clone();
            caches.open(CACHE_NAME).then((cache) => cache.put(req, clone));
          }
          return networkRes;
        })
        .catch(() => {
          return caches.match(req).then((cached) => cached || caches.match('/index.html'));
        })
    );
    return;
  }

  // 3. Stale-while-revalidate for same-origin static assets
  event.respondWith(
    caches.match(req).then((cached) => {
      const fetchPromise = fetch(req)
        .then((networkRes) => {
          if (networkRes && networkRes.ok) {
            const clone = networkRes.clone();
            caches.open(CACHE_NAME).then((cache) => cache.put(req, clone));
          }
          return networkRes;
        })
        .catch(() => null);

      return cached || fetchPromise;
    })
  );
});