const APP_SHELL_CACHE = 'privatechat-app-shell-v1';
const APP_SHELL_FILES = [
  '/',
  '/index.html',
  '/manifest.webmanifest',
  '/favicon.ico',
  '/apple-touch-icon.png',
  '/pwa-192x192.png',
  '/pwa-512x512.png',
  '/maskable-192x192.png',
  '/maskable-512x512.png',
];

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

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

self.addEventListener('fetch', (event) => {
  const { request } = event;

  if (request.method !== 'GET') {
    return;
  }

  const url = new URL(request.url);

  if (url.origin !== self.location.origin || url.pathname.startsWith('/api/') || url.pathname === '/ws') {
    return;
  }

  if (request.mode === 'navigate') {
    event.respondWith(
      fetch(request)
        .then((response) => {
          const responseCopy = response.clone();
          void caches.open(APP_SHELL_CACHE).then((cache) => cache.put('/index.html', responseCopy));
          return response;
        })
        .catch(async () => {
          const cache = await caches.open(APP_SHELL_CACHE);
          return cache.match('/index.html') || Response.error();
        }),
    );
    return;
  }

  event.respondWith(
    caches.match(request).then((cachedResponse) => {
      const networkFetch = fetch(request)
        .then((response) => {
          if (response.ok) {
            const responseCopy = response.clone();
            void caches.open(APP_SHELL_CACHE).then((cache) => cache.put(request, responseCopy));
          }

          return response;
        })
        .catch(() => cachedResponse || Response.error());

      return cachedResponse || networkFetch;
    }),
  );
});