const CACHE_NAME = 'offline-v1';
const ASSETS = [
  '/css/main.css',
  '/js/shared/theme.js',
  '/js/post/download.js',
  '/js/post/lazyimg.js',
  '/package/js/prism.min.js',
  '/package/js/prism-python.min.js',
  '/package/js/mathjax.js',
  '/css/icons/back.webp',
  '/css/icons/written.webp',
  '/css/icons/date.webp',
  '/css/icons/magnifier.webp',
  '/css/icons/save.webp',
  '/css/icons/script.webp'
];

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

self.addEventListener('fetch', e => {
  e.respondWith(
    caches.match(e.request).then(res => res || fetch(e.request).then(resp => {
      if (e.request.url.startsWith(self.location.origin)) {
        const copy = resp.clone();
        caches.open(CACHE_NAME).then(c => c.put(e.request, copy));
      }
      return resp;
    }))
  );
});