sw.js

const CACHE_NAME = 'obscuralang-cache-v1.0.0';
const OFFLINE_URL = '404.html';

const urlsToCache = [
  '/',
  '/index.html',
  '/404.html',
  '/obscuralang.css',
  '/obscuralang.js',
  '/ObscuraLang.webp',
  '/ObscuraLang.ico'
];

// Install event - cache initial resources
self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then(cache => {
        console.log('Opened cache');
        return cache.addAll(urlsToCache);
      })
      .then(() => self.skipWaiting())
  );
});

// Activate event - clean up old caches
self.addEventListener('activate', event => {
  event.waitUntil(
    caches.keys().then(cacheNames => {
      return Promise.all(
        cacheNames.map(cacheName => {
          if (cacheName !== CACHE_NAME) {
            console.log('Deleting old cache:', cacheName);
            return caches.delete(cacheName);
          }
        })
      );
    }).then(() => self.clients.claim())
  );
});

// Fetch event - network first, then cache
self.addEventListener('fetch', event => {
  event.respondWith(
    fetch(event.request)
      .then(response => {
        // Check if we received a valid response
        if (!response || response.status !== 200 || response.type !== 'basic') {
          return response;
        }

        // Clone the response as it can only be consumed once
        const responseToCache = response.clone();

        // Update cache with new response
        caches.open(CACHE_NAME)
          .then(cache => {
            // Only cache GET requests
            if (event.request.method === 'GET') {
              cache.put(event.request, responseToCache);
            }
          });

        return response;
      })
      .catch(error => {
        console.log('Fetch failed; returning offline page instead.', error);
        
        return caches.match(event.request)
          .then(response => {
            // Return cached response if available
            if (response) {
              return response;
            }
            
            // Otherwise return the offline page
            if (event.request.mode === 'navigate') {
              return caches.match(OFFLINE_URL);
            }
            
            // If neither available, return error response
            return new Response('Network error', {
              status: 408,
              headers: new Headers({
                'Content-Type': 'text/plain'
              })
            });
          });
    })
  );
});

// Handle messages from clients
self.addEventListener('message', event => {
  if (event.data === 'skipWaiting') {
    self.skipWaiting();
  }
});