sw.js

const CACHE = 'asterion-live-v1.1';
const CORE = [
  './',
  './index.html',
  './css/styles.css',
  './js/bootstrap.js',
  './js/app.js',
  './js/versions.js',
  './manifest.webmanifest',
  './assets/asterion-mark.svg',
  './assets/icons/icon-192.png',
  './assets/icons/icon-512.png'
];

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

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

async function networkFirst(request) {
  const cache = await caches.open(CACHE);
  try {
    const response = await fetch(request);
    if (response.ok) await cache.put(request, response.clone());
    return response;
  } catch {
    return (await cache.match(request)) || (await cache.match('./index.html'));
  }
}

async function cacheFirst(request) {
  const cache = await caches.open(CACHE);
  const cached = await cache.match(request);
  if (cached) return cached;
  const response = await fetch(request);
  if (response.ok || response.type === 'opaque') await cache.put(request, response.clone());
  return response;
}

self.addEventListener('fetch', (event) => {
  if (event.request.method !== 'GET') return;
  const url = new URL(event.request.url);
  const sameOrigin = url.origin === self.location.origin;
  const approvedCdn = url.hostname === 'cdn.jsdelivr.net';
  if (!sameOrigin && !approvedCdn) return;

  if (event.request.mode === 'navigate') {
    event.respondWith(networkFirst(event.request));
    return;
  }
  event.respondWith(cacheFirst(event.request));
});