const CACHE = 'wycz-v1';
const CORE = [
  '/',
  '/css/style.css',
  '/js/app.js',
  '/manifest.webmanifest',
  '/images/logo.png',
  '/images/icons/icon-96.png',
  '/images/icons/icon-192.png',
  '/images/icons/icon-512.png'
];

self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE)
      .then((cache) => cache.addAll(CORE))
      .then(() => 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 req = event.request;
  if (req.method !== 'GET') return;

  const url = new URL(req.url);
  if (url.origin !== self.location.origin) return;

  if (url.pathname.startsWith('/api/')) {
    event.respondWith(fetch(req));
    return;
  }

  if (req.mode === 'navigate') {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const copy = res.clone();
          caches.open(CACHE).then((c) => c.put('/', copy));
          return res;
        })
        .catch(() => caches.match('/'))
    );
    return;
  }

  event.respondWith(
    caches.match(req).then((cached) => {
      const network = fetch(req)
        .then((res) => {
          if (res.ok) {
            const copy = res.clone();
            caches.open(CACHE).then((c) => c.put(req, copy));
          }
          return res;
        })
        .catch(() => cached);
      return cached || network;
    })
  );
});