/**
 * diora service worker — caches the app shell for offline use.
 */

const CACHE = 'diora-v1';
const SHELL = [
  '/',
  '/static/css/app.css',
  '/static/js/app.js',
  '/static/manifest.json',
];

// Install: pre-cache the app shell
self.addEventListener('install', function (event) {
  event.waitUntil(
    caches.open(CACHE).then(function (cache) {
      return cache.addAll(SHELL);
    })
  );
  // Activate immediately without waiting for old tabs to close
  self.skipWaiting();
});

// Activate: remove stale caches from previous versions
self.addEventListener('activate', function (event) {
  event.waitUntil(
    caches.keys().then(function (keys) {
      return Promise.all(
        keys.filter(function (key) { return key !== CACHE; })
            .map(function (key) { return caches.delete(key); })
      );
    }).then(function () {
      return self.clients.claim();
    })
  );
});

// Fetch: serve from cache, fall back to network
self.addEventListener('fetch', function (event) {
  // Only handle GET requests; let POST/SSE etc. pass through
  if (event.request.method !== 'GET') return;

  // Don't intercept SSE or API requests
  const url = new URL(event.request.url);
  if (url.pathname.startsWith('/radio/sse/') ||
      url.pathname.startsWith('/radio/record/') ||
      url.pathname.startsWith('/radio/affiliate/') ||
      url.pathname.startsWith('/admin/')) {
    return;
  }

  event.respondWith(
    caches.match(event.request).then(function (cached) {
      if (cached) return cached;
      return fetch(event.request).then(function (response) {
        // Cache successful GET responses for shell assets
        if (response && response.status === 200 && response.type === 'basic') {
          const clone = response.clone();
          caches.open(CACHE).then(function (cache) {
            cache.put(event.request, clone);
          });
        }
        return response;
      });
    })
  );
});