// Cache the app shell with paths relative to this worker's scope
// so a subfolder deploy (Vite base: './') keeps working.
const CACHE_NAME = 'matematika-shell-v3'

function scopeUrl(path) {
  return new URL(path, self.registration.scope).href
}

const ASSETS_TO_CACHE = [
  './',
  './index.html',
  './manifest.json',
  './favicon/site.webmanifest',
  './favicon/web-app-manifest-192x192.png',
  './favicon/web-app-manifest-512x512.png',
  './favicon/apple-touch-icon.png',
  './favicon/favicon-96x96.png'
].map(scopeUrl)

self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(CACHE_NAME).then(cache =>
      cache.addAll(ASSETS_TO_CACHE).catch(err => {
        console.warn('Precache failed (continuing):', err)
      })
    )
  )
  self.skipWaiting()
})

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

self.addEventListener('fetch', event => {
  if (event.request.method !== 'GET') return

  if (event.request.mode === 'navigate') {
    event.respondWith(
      fetch(event.request).then(resp => {
        if (resp && resp.status === 200) {
          const respClone = resp.clone()
          caches.open(CACHE_NAME).then(cache => cache.put(event.request, respClone))
        }
        return resp
      }).catch(() => caches.match(scopeUrl('./index.html')))
    )
    return
  }

  event.respondWith(
    caches.match(event.request).then(cached => {
      const networkFetch = fetch(event.request).then(resp => {
        if (resp && resp.status === 200) {
          const respClone = resp.clone()
          caches.open(CACHE_NAME).then(cache => cache.put(event.request, respClone))
        }
        return resp
      }).catch(() => null)
      return cached || networkFetch
    })
  )
})

self.addEventListener('message', event => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting()
  }
})