const CACHE_NAME = 'rpigroupplay-v4';
const ASSETS = [
  './',
  './index.php',
  './manifest.json',
  './css/style.css',
  './css/bootstrap.css',
  './css/animation.css',
  './js/app.js',
  './js/bootstrap.js',
  './img/RpiGroupPlayWHITE.png',
  './img/logoapp.png'
];

// Install Event
self.addEventListener('install', (e) => {
  e.waitUntil(
    caches.open(CACHE_NAME)
      .then((cache) => {
        console.log('[Service Worker] Caching static shell');
        return cache.addAll(ASSETS).catch(err => {
          console.warn('[Service Worker] Asset caching warning:', err);
        });
      })
      .then(() => self.skipWaiting())
  );
});

// Activate Event
self.addEventListener('activate', (e) => {
  e.waitUntil(
    caches.keys().then((keys) => {
      return Promise.all(
        keys.map((key) => {
          if (key !== CACHE_NAME) {
            console.log('[Service Worker] Removing old cache', key);
            return caches.delete(key);
          }
        })
      );
    }).then(() => self.clients.claim())
  );
});

// Fetch Event
self.addEventListener('fetch', (e) => {
  const url = e.request.url;

  // Skip non-GET requests
  if (e.request.method !== 'GET') {
    return;
  }

  // Bypass streaming content, APIs, and external domains (like radio/tv streams)
  if (
    url.includes('stream') ||
    url.includes('.mp3') ||
    url.includes('.aac') ||
    url.includes('.m3u8') ||
    url.includes('.ts') ||
    url.includes('icecast') ||
    url.includes('shoutcast') ||
    url.includes('radiocitta105') ||
    url.includes('radiodiffusionelibera') ||
    !url.startsWith(self.location.origin)
  ) {
    return; // Let the browser handle standard streaming/external fetch requests directly
  }

  e.respondWith(
    caches.match(e.request).then((cachedResponse) => {
      if (cachedResponse) {
        // Return cached resource immediately and fetch fresh copy in background (Stale-While-Revalidate)
        fetch(e.request).then((networkResponse) => {
          if (networkResponse.status === 200) {
            caches.open(CACHE_NAME).then((cache) => {
              cache.put(e.request, networkResponse);
            });
          }
        }).catch(() => {
          // Silent catch network failures
        });
        return cachedResponse;
      }

      // Fallback to network
      return fetch(e.request).then((response) => {
        // Cache standard successful requests
        if (response.status === 200) {
          const responseClone = response.clone();
          caches.open(CACHE_NAME).then((cache) => {
            cache.put(e.request, responseClone);
          });
        }
        return response;
      }).catch(() => {
        // Fallback offline: restituiamo l'app shell se l'utente sta navigando
        if (e.request.mode === 'navigate') {
          return caches.match('./index.php');
        }
      });
    })
  );
});