const CACHE_NAME = "my-cache";
const OFFLINE_URL = "/static/offline.html";

self.addEventListener("install", (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      return cache.addAll([
        "/",
        "/static/css/portal.css",
        "/static/js/app.js",
        "/static/images/favicon.png",
        OFFLINE_URL,
      ]);
    })
  );
});

self.addEventListener("fetch", (event) => {
  if (event.request.mode === "navigate") {
    event.respondWith(
      fetch(event.request).catch(() => {
        return caches.match(OFFLINE_URL);
      })
    );
  } else {
    event.respondWith(
      caches.match(event.request).then((response) => {
        return response || fetch(event.request);
      })
    );
  }
});