const CACHE_NAME = 'whatsapp-static-v1';
const OFFLINE_URL = '/index.php';
const ASSETS_TO_CACHE = [
  OFFLINE_URL,
  '/assets/css/styles.css',
  '/assets/js/app_simple.js',
  '/manifest.json'
];

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

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) => {
  if (event.request.method !== 'GET') return;
  event.respondWith(
    caches.match(event.request).then(cached => {
      if (cached) return cached;
      return fetch(event.request).then(resp => {
        // cache same-origin GET responses
        try {
          if (resp && resp.status === 200 && resp.type === 'basic') {
            const clone = resp.clone();
            caches.open(CACHE_NAME).then(cache => cache.put(event.request, clone));
          }
        } catch (e) {}
        return resp;
      }).catch(() => caches.match(OFFLINE_URL));
    })
  );
});