// A name for our cache
const CACHE_NAME = 'timetracker-v1';

// The files that make up the "app shell" - the minimum needed to run
const urlsToCache = [
  '/',
  '/index.html',
  // You can also cache the CDN assets if you want
  'https://cdn.tailwindcss.com',
  'https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap'
];

// 1. Installation: Open the cache and add the app shell files.
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then((cache) => {
        console.log('Opened cache');
        return cache.addAll(urlsToCache);
      })
  );
});

// 2. Fetch: Intercept network requests.
self.addEventListener('fetch', (event) => {
  // We only want to cache GET requests
  if (event.request.method !== 'GET') {
    return;
  }
  
  event.respondWith(
    caches.match(event.request)
      .then((response) => {
        // If the file is in the cache, serve it.
        if (response) {
          return response;
        }
        // Otherwise, fetch it from the network.
        return fetch(event.request);
      })
  );
});