/* Nur Static-Assets cachen — nie HTML-Navigation abfangen (sonst falsche Seite in Chrome). */
const CACHE = "grotti-shell-v2";

self.addEventListener("install", (event) => {
  self.skipWaiting();
  event.waitUntil(
    caches.open(CACHE).then((cache) =>
      cache.addAll([
        "/static/grotti.css?v=56",
        "/static/api.js?v=29",
        "/static/ui.js?v=3",
      ]).catch(() => undefined)
    )
  );
});

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;
  // Dokument-Navigation immer ans Netz — kein Fallback auf „/“.
  if (req.mode === "navigate") return;
  const url = new URL(req.url);
  if (url.origin !== self.location.origin) return;
  if (url.pathname.startsWith("/api/")) return;
  if (!url.pathname.startsWith("/static/")) return;

  event.respondWith(
    fetch(req)
      .then((res) => {
        if (res.ok) {
          const copy = res.clone();
          caches.open(CACHE).then((c) => c.put(req, copy)).catch(() => {});
        }
        return res;
      })
      .catch(() => caches.match(req))
  );
});