const CACHE = 'gibbz-shell-v1';
const SHELL = ['/', '/index.html', '/style.css', '/app.js', '/manifest.webmanifest'];

self.addEventListener('install', (event) => {
  event.waitUntil(caches.open(CACHE).then((cache) => cache.addAll(SHELL)));
  self.skipWaiting();
});

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

// Never touch the signaling socket or live API data — only cache the static
// app shell so the UI can still load (offline/flaky network), not room state.
self.addEventListener('fetch', (event) => {
  const { request } = event;
  const url = new URL(request.url);
  if (request.method !== 'GET' || url.origin !== self.location.origin) return;
  if (url.pathname.startsWith('/api/') || url.pathname === '/ws') return;

  event.respondWith(
    fetch(request)
      .then((response) => {
        const copy = response.clone();
        caches.open(CACHE).then((cache) => cache.put(request, copy));
        return response;
      })
      .catch(() => caches.match(request).then((cached) => cached || caches.match('/index.html')))
  );
});