const CACHE_NAME = "readabook-shell-v2";
const SHELL = ["/", "/index.html", "/manifest.webmanifest", "/icons/readabook.svg"];

self.addEventListener("install", (event) => {
  event.waitUntil(caches.open(CACHE_NAME).then((cache) => cache.addAll(SHELL)));
  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) => {
  const url = new URL(event.request.url);
  if (event.request.method !== "GET" || ["/auth", "/admin", "/books", "/progress"].some((path) => url.pathname.startsWith(path))) {
    return;
  }
  if (event.request.mode === "navigate") {
    event.respondWith(
      fetch(event.request)
        .then((response) => {
          const copy = response.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put("/index.html", copy));
          return response;
        })
        .catch(() => caches.match("/index.html").then((hit) => hit || caches.match("/")))
    );
    return;
  }
  event.respondWith(
    caches.match(event.request).then((hit) => hit || fetch(event.request))
  );
});