/* schattenpost Service Worker — reines Offline-Caching der App-Shell.
   Sendet NICHTS an einen Server. Cache-first, kein Netzwerk-Fallback nötig,
   sobald die Shell einmal geladen ist. */
const CACHE = 'schattenpost-v5';
const SHELL = [
  './',
  './index.html',
  './manifest.webmanifest',
  './favicon.svg',
  './icon-192.png',
  './icon-512.png',
];

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

self.addEventListener('activate', (e) => {
  e.waitUntil(
    caches.keys()
      .then((keys) => Promise.all(keys.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)));
});