/* Cyrene v2 PWA service worker — core-resource caching + offline shell. */
const CACHE = "cyrene-web-v1";
const PRECACHE = ["/", "/index.html", "/manifest.json", "/images/Cyrene_Avatar/3rd_Form/Cyrene-3F-Q-Happy-1.png"];

self.addEventListener("install", (event) => {
  event.waitUntil(
    caches
      .open(CACHE)
      .then((cache) => cache.addAll(PRECACHE))
      .then(() => self.skipWaiting())
  );
});

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

self.addEventListener("fetch", (event) => {
  const req = event.request;
  if (req.method !== "GET") return;

  const url = new URL(req.url);
  if (url.origin !== self.location.origin) return; // let API/WS pass through

  // Network-first for document navigations so the shell stays fresh, falling
  // back to cached index.html when offline.
  if (req.mode === "navigate") {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const copy = res.clone();
          caches.open(CACHE).then((cache) => cache.put("/index.html", copy));
          return res;
        })
        .catch(() => caches.match("/index.html"))
    );
    return;
  }

  // Cache-first for static assets (hashed by Vite) with background refresh.
  event.respondWith(
    caches.match(req).then((cached) => {
      const fetched = fetch(req)
        .then((res) => {
          if (res && res.status === 200) {
            const copy = res.clone();
            caches.open(CACHE).then((cache) => cache.put(req, copy));
          }
          return res;
        })
        .catch(() => cached);
      return cached || fetched;
    })
  );
});