// sw.js — minimal offline cache so the PWA launches without a network.
const CACHE = 'babymobile-v8';
const ASSETS = [
  './', './index.html', './styles.css',
  './app.js', './ble.js', './wav.js',
  './manifest.webmanifest', './icon.svg',
];

self.addEventListener('install', (e) => {
  e.waitUntil(caches.open(CACHE).then((c) => c.addAll(ASSETS)).then(() => self.skipWaiting()));
});

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

// Cache-first for app shell; network passthrough otherwise.
self.addEventListener('fetch', (e) => {
  const url = new URL(e.request.url);
  if (e.request.method !== 'GET' || url.origin !== location.origin) return;
  e.respondWith(
    caches.match(e.request).then((hit) => hit || fetch(e.request).then((res) => {
      const copy = res.clone();
      caches.open(CACHE).then((c) => c.put(e.request, copy)).catch(() => {});
      return res;
    }).catch(() => hit))
  );
});