// EasyStream Service Worker (lightweight, safe defaults)
const CACHE_VERSION = 'es-v1';
const STATIC_CACHE = `${CACHE_VERSION}-static`;
const PRECACHE = [
  '/index.js',
  '/manifest.json'
];

self.addEventListener('install', (event) => {
  event.waitUntil((async () => {
    const cache = await caches.open(STATIC_CACHE);
    await cache.addAll(PRECACHE);
    self.skipWaiting();
  })());
});

self.addEventListener('activate', (event) => {
  event.waitUntil((async () => {
    const keys = await caches.keys();
    await Promise.all(keys.filter(k => !k.startsWith(CACHE_VERSION)).map(k => caches.delete(k)));
    self.clients.claim();
  })());
});

self.addEventListener('fetch', (event) => {
  const url = event.request.url;
  // never cache uploads or HLS segments/manifests
  if (url.includes('upload') || url.includes('uploader') || url.includes('index.m3u8') || url.includes('.ts')) {
    return; // bypass SW
  }

  // Navigation requests: network-first with cache fallback for basic offline shell
  if (event.request.mode === 'navigate') {
    event.respondWith((async () => {
      try {
        const fresh = await fetch(event.request);
        return fresh;
      } catch (e) {
        const cache = await caches.open(STATIC_CACHE);
        const shell = await cache.match('/index.js');
        return shell || Response.error();
      }
    })());
    return;
  }

  // Others: stale-while-revalidate
  event.respondWith((async () => {
    const cached = await caches.match(event.request);
    const fetchPromise = fetch(event.request).then((networkResponse) => {
      if (networkResponse && networkResponse.ok && event.request.method === 'GET') {
        const copy = networkResponse.clone();
        caches.open(STATIC_CACHE).then((cache) => cache.put(event.request, copy)).catch(() => {});
      }
      return networkResponse;
    }).catch(() => cached);
    return cached || fetchPromise;
  })());
});