// Minimal service worker: offline shell only. No data caching.
const CACHE = 'ticketing-shell-v1';
const SHELL = ['/', '/icon.svg', '/manifest.webmanifest'];

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

self.addEventListener('activate', (event) => {
  event.waitUntil(
    caches.keys().then((keys) =>
      Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k))),
    ),
  );
  self.clients.claim();
});

self.addEventListener('fetch', (event) => {
  const req = event.request;
  if (req.method !== 'GET') return;

  const url = new URL(req.url);
  // Never cache API calls — they must always hit the server
  if (url.pathname.startsWith('/api/')) return;

  // Network-first for navigation, fall back to cached shell
  if (req.mode === 'navigate') {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const clone = res.clone();
          caches.open(CACHE).then((c) => c.put('/', clone));
          return res;
        })
        .catch(() => caches.match('/')),
    );
    return;
  }

  // Cache-first for static assets
  if (url.origin === self.location.origin) {
    event.respondWith(
      caches.match(req).then((cached) => {
        if (cached) return cached;
        return fetch(req).then((res) => {
          if (res.ok && res.type === 'basic') {
            const clone = res.clone();
            caches.open(CACHE).then((c) => c.put(req, clone));
          }
          return res;
        });
      }),
    );
  }
});