/*
 * Service Worker des AI-Act-Kompass.
 * Strategie: Network-first mit Cache-Fallback — die App bleibt offline
 * nutzbar (Handy/Mac), lädt aber online immer die aktuelle Version.
 * Es werden ausschließlich eigene (same-origin) GET-Antworten gecacht.
 */
const CACHE = 'ai-act-kompass-v1';

self.addEventListener('install', () => {
  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 { request } = event;
  if (request.method !== 'GET' || new URL(request.url).origin !== location.origin) {
    return;
  }
  event.respondWith(
    caches.open(CACHE).then(async (cache) => {
      try {
        const fresh = await fetch(request);
        if (fresh.ok) {
          cache.put(request, fresh.clone());
        }
        return fresh;
      } catch (err) {
        const cached = await cache.match(request, { ignoreSearch: true });
        if (cached) return cached;
        if (request.mode === 'navigate') {
          const shell = await cache.match('./index.html');
          if (shell) return shell;
        }
        throw err;
      }
    }),
  );
});