// Minimal service worker: cache the app shell so site is quickly available and installable.
const CACHE_NAME = 'phone-webcam-v1';
const FILES_TO_CACHE = [
  '/',
  '/manifest.json',
  '/static/index.html',
  '/static/index.html', // duplicated intentionally harmless
  '/static/icon-192.png'
];

self.addEventListener('install', (evt) => {
  evt.waitUntil(
    caches.open(CACHE_NAME).then(cache => cache.addAll(FILES_TO_CACHE))
  );
  self.skipWaiting();
});

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

self.addEventListener('fetch', (evt) => {
  // network-first for /offer (dynamic), cache-first for app shell assets
  const url = new URL(evt.request.url);
  if (url.pathname === '/offer') {
    // passthrough to network
    evt.respondWith(fetch(evt.request));
    return;
  }

  evt.respondWith(
    caches.match(evt.request).then(cached => cached || fetch(evt.request).then(resp => {
      // optionally cache dynamic responses here
      return resp;
    }).catch(() => {
      // fallback could be a blank response for image or offline page
      return caches.match('/');
    }))
  );
});