// Service worker minimal : résilience réseau (3G/4G irrégulier) et usage
// hors-ligne des pages déjà visitées. Stratégie stale-while-revalidate.
const CACHE_NAME = "gwada-sirius-v2";

self.addEventListener("install", (event) => {
  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) => {
  if (event.request.method !== "GET") return;
  const url = new URL(event.request.url);
  if (url.origin !== self.location.origin) return;

  event.respondWith(
    caches.open(CACHE_NAME).then(async (cache) => {
      const cached = await cache.match(event.request);
      const network = fetch(event.request)
        .then((response) => {
          if (response.ok) cache.put(event.request, response.clone());
          return response;
        })
        .catch(() => cached);

      return cached || network;
    })
  );
});