/* 小暖 PWA Service Worker：网络优先，断网时回退缓存 */
const CACHE = 'xiaonuan-v1';

self.addEventListener('install', (e) => {
  e.waitUntil(caches.open(CACHE).then((c) => c.addAll(['/', '/index.html', '/icon.svg'])));
  self.skipWaiting();
});

self.addEventListener('activate', (e) => {
  e.waitUntil(clients.claim());
});

self.addEventListener('fetch', (e) => {
  if (e.request.method !== 'GET') return;
  e.respondWith(
    fetch(e.request)
      .then((res) => {
        const copy = res.clone();
        caches.open(CACHE).then((c) => c.put(e.request, copy));
        return res;
      })
      .catch(() => caches.match(e.request))
  );
});