const VERSION = "dhikr-v4";
const SHELL = [
  "./",
  "./index.html",
  "./manifest.webmanifest",
  "./icon-192.png",
  "./icon-512.png",
  "./icon-maskable-512.png",
  "./apple-touch-icon.png"
];

self.addEventListener("install", (e) => {
  e.waitUntil(
    caches.open(VERSION).then((c) => c.addAll(SHELL)).then(() => self.skipWaiting())
  );
});

self.addEventListener("activate", (e) => {
  e.waitUntil(
    caches.keys()
      .then((keys) => Promise.all(keys.filter((k) => k !== VERSION).map((k) => caches.delete(k))))
      .then(() => self.clients.claim())
  );
});

self.addEventListener("fetch", (e) => {
  const url = new URL(e.request.url);

  // Google Fonts: stale-while-revalidate so typography survives offline
  if (url.hostname === "fonts.googleapis.com" || url.hostname === "fonts.gstatic.com") {
    e.respondWith(
      caches.open(VERSION).then(async (cache) => {
        const cached = await cache.match(e.request);
        const network = fetch(e.request)
          .then((res) => { if (res.ok) cache.put(e.request, res.clone()); return res; })
          .catch(() => cached);
        return cached || network;
      })
    );
    return;
  }

  // App shell: cache-first, fall back to network, fall back to cached index
  if (e.request.method === "GET" && url.origin === self.location.origin) {
    e.respondWith(
      caches.match(e.request).then(
        (cached) =>
          cached ||
          fetch(e.request)
            .then((res) => {
              if (res.ok) {
                const clone = res.clone();
                caches.open(VERSION).then((c) => c.put(e.request, clone));
              }
              return res;
            })
            .catch(() => caches.match("./index.html"))
      )
    );
  }
});