sw.js

// Service Worker for licod.io
// Provides offline support and caching

const CACHE_NAME = 'licod-v13'
const urlsToCache = [
  '/',
  '/index.html',
  '/style.css',
  '/script.js',
  '/commands_en.json',
  '/manifest.json'
]

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

// Fetch event - serve from cache, fallback to network
self.addEventListener('fetch', event => {
  event.respondWith(
    caches.match(event.request)
      .then(response => {
        // Cache hit - return response
        if (response) {
          return response
        }
        return fetch(event.request)
      }
    )
  )
})

// Activate event - clean up old caches
self.addEventListener('activate', event => {
  const cacheWhitelist = [CACHE_NAME]
  event.waitUntil(
    caches.keys().then(cacheNames => {
      return Promise.all(
        cacheNames.map(cacheName => {
          if (cacheWhitelist.indexOf(cacheName) === -1) {
            return caches.delete(cacheName)
          }
        })
      )
    })
  )
})