const CACHE_NAME = 'sulfur-cache-v3';
const urlsToCache = [
  './index.html',
  './css/style.css',
  './js/launcher.js',
  './manifest.json',
  './instances/sulfur.html',
  './assets/icon-192.png',
  './assets/icon-512.png',
  './assets/favicon.png',
  './assets/bg-atm10.jpg',
  './assets/bg-vanilla8.jpg',
  './assets/thumb-atm10.png',
  './assets/thumb-vanilla8.png'
];

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

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

self.addEventListener('fetch', event => {
  event.respondWith(
    caches.match(event.request).then(response => response || fetch(event.request))
  );
});