pupilfirst/pupilfirst

// https://developers.google.com/web/updates/2015/03/push-notifications-on-the-open-web

self.addEventListener('push', function (event) {
  var data = event.data.json();
  event.waitUntil(
    self.registration.showNotification(data.title, {
      icon: data.icon,
      tag: data.tag
    })
  );
});

self.addEventListener('notificationclick', function (event) {
  // Android doesn't close the notification when you click on it
  // See: http://crbug.com/463146
  event.notification.close();

  // This looks to see if the current is already open and
  // focuses if it is
  event.waitUntil(
    clients.matchAll({
      type: "window"
    })
      .then(function (clientList) {
        for (var i = 0; i < clientList.length; i++) {
          var client = clientList[i];
          if (client.url == "/notifications/".concat(event.notification.tag) && 'focus' in client)
            return client.focus();
        }
        if (clients.openWindow) {
          return clients.openWindow("/notifications/".concat(event.notification.tag));
        }
      })
  );
});

// Incrementing OFFLINE_VERSION will kick off the install event and force
// previously cached resources to be updated from the network.
const OFFLINE_VERSION = 1;
const CACHE_NAME = "offline";
const OFFLINE_URL = "offline";

self.addEventListener("install", (event) => {
  event.waitUntil(
    (async () => {
      const cache = await caches.open(CACHE_NAME);
      // Setting {cache: 'reload'} in the new request will ensure that the
      // response isn't fulfilled from the HTTP cache; i.e., it will be from
      // the network.
      await cache.add(new Request(OFFLINE_URL, {cache: "reload"}));
    })()
  );
  // Force the waiting service worker to become the active service worker.
  self.skipWaiting();
});

self.addEventListener("activate", (event) => {
  event.waitUntil(
    (async () => {
      // Enable navigation preload if it's supported.
      // See https://developers.google.com/web/updates/2017/02/navigation-preload
      if ("navigationPreload" in self.registration) {
        await self.registration.navigationPreload.enable();
      }
    })()
  );

  // Tell the active service worker to take control of the page immediately.
  self.clients.claim();
});

self.addEventListener("fetch", (event) => {
  // We only want to call event.respondWith() if this is a navigation request
  // for an HTML page.
  if (event.request.mode === "navigate") {
    event.respondWith(
      (async () => {
        try {
          // First, try to use the navigation preload response if it's supported.
          const preloadResponse = await event.preloadResponse;
          if (preloadResponse) {
            return preloadResponse;
          }

          // Always try the network first.
          const networkResponse = await fetch(event.request);
          return networkResponse;
        } catch (error) {
          // catch is only triggered if an exception is thrown, which is likely
          // due to a network error.
          // If fetch() returns a valid HTTP response with a response code in
          // the 4xx or 5xx range, the catch() will NOT be called.
          console.log("Fetch failed; returning offline page instead.", error);

          const cache = await caches.open(CACHE_NAME);
          const cachedResponse = await cache.match(OFFLINE_URL);
          return cachedResponse;
        }
      })()
    );
  }
});