const CACHE_NAME = 'securewatch-v2';
const FILES_TO_CACHE = [
  './index.html',
  './manifest.json',
  './icon-192.png',
  './icon-512.png'
];

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

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

self.addEventListener('fetch', (event) => {
  event.respondWith(
    (async () => {
      const cached = await caches.match(event.request);
      if(cached) return cached;
      try{
        return await fetch(event.request);
      } catch(err){
        return new Response('', { status: 503, statusText: 'Offline e sem versão em cache' });
      }
    })()
  );
});