/* Service Worker — SLC-Workshop Companion (App-Shell, offline-first) */
const CACHE = "slc-companion-v1";
const ASSETS = ["./", "index.html", "manifest.webmanifest", "icon.svg"];

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

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

self.addEventListener("fetch", (e) => {
  if (e.request.method !== "GET") return;
  e.respondWith(
    caches.match(e.request).then((hit) =>
      hit ||
      fetch(e.request)
        .then((resp) => {
          const copy = resp.clone();
          caches.open(CACHE).then((c) => c.put(e.request, copy));
          return resp;
        })
        .catch(() => caches.match("index.html"))
    )
  );
});