/*
 * SiMS HQ service worker — makes the console installable (PWA) and fast on repeat
 * visits, without pretending to be a fully offline app (it is an online ops console).
 *
 * Strategy, deliberately conservative:
 *  - /api and /share are NEVER touched — always straight to the network (live data,
 *    auth, the public PDF route). The SW must never cache or stale those.
 *  - Navigations (opening a page) are network-first, falling back to the cached app
 *    shell so a flaky connection still opens the UI instead of the browser error page.
 *  - Hashed static assets (/assets/*, icons) are cache-first: their names change every
 *    build, so a cached copy is always the right version and new builds self-populate.
 *  - Only GET, same-origin. Everything else falls through to the network.
 */
const CACHE = 'sims-hq-v1'
const SHELL = ['/', '/index.html', '/manifest.webmanifest', '/favicon.svg', '/icon.svg']

self.addEventListener('install', (event) => {
  event.waitUntil(caches.open(CACHE).then((c) => c.addAll(SHELL)).then(() => self.skipWaiting()))
})

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

self.addEventListener('fetch', (event) => {
  const req = event.request
  if (req.method !== 'GET') return
  const url = new URL(req.url)
  if (url.origin !== self.location.origin) return
  // Never intercept the API or the public share route — always live.
  if (url.pathname.startsWith('/api') || url.pathname.startsWith('/share')) return

  // App navigations: network-first with a shell fallback.
  if (req.mode === 'navigate') {
    event.respondWith(
      fetch(req)
        .then((res) => {
          const copy = res.clone()
          caches.open(CACHE).then((c) => c.put('/', copy)).catch(() => {})
          return res
        })
        .catch(() => caches.match('/').then((m) => m || caches.match('/index.html'))),
    )
    return
  }

  // Static assets: cache-first, then populate.
  event.respondWith(
    caches.match(req).then((hit) => hit || fetch(req).then((res) => {
      if (res.ok && res.type === 'basic') {
        const copy = res.clone()
        caches.open(CACHE).then((c) => c.put(req, copy)).catch(() => {})
      }
      return res
    }).catch(() => hit)),
  )
})