// ============================================================
// SERVICE WORKER — Cache the React shell + manifest.
// Network-first for API (medical data must always be fresh).
// Hashed Vite assets are NOT precached — they change every build,
// the browser HTTP cache plus immutable Cache-Control handles them.
// ============================================================

var CACHE_NAME = 'pedscribe-v13';
var SHELL_ASSETS = [
  '/',
  '/manifest.json',
];

// Install: precache shell. Errors swallowed so a missing single
// asset doesn't break SW install entirely.
self.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open(CACHE_NAME).then(function(cache) {
      return Promise.allSettled(SHELL_ASSETS.map(function(url) {
        return cache.add(url).catch(function() {});
      }));
    }).then(function() { return self.skipWaiting(); })
  );
});

// Activate: clear old caches (deletes pedscribe-v12 and earlier).
self.addEventListener('activate', function(event) {
  event.waitUntil(
    caches.keys().then(function(names) {
      return Promise.all(
        names.filter(function(name) { return name !== CACHE_NAME; })
             .map(function(name) { return caches.delete(name); })
      );
    }).then(function() { return self.clients.claim(); })
  );
});

self.addEventListener('fetch', function(event) {
  if (event.request.method !== 'GET') return;
  var url = new URL(event.request.url);
  // Same-origin only; skip cross-origin (CDN, fonts, etc.)
  if (url.origin !== self.location.origin) return;
  // API: network only — never cache medical data.
  if (url.pathname.startsWith('/api/')) return;
  // Hashed Vite assets: serve from network, fall back to cache if offline.
  if (url.pathname.startsWith('/app/assets/')) {
    event.respondWith(
      fetch(event.request).catch(function() { return caches.match(event.request); })
    );
    return;
  }
  // SPA shell + everything else: cache-first with network update.
  event.respondWith(
    caches.match(event.request).then(function(cached) {
      var fetchPromise = fetch(event.request).then(function(resp) {
        if (resp && resp.status === 200) {
          var copy = resp.clone();
          caches.open(CACHE_NAME).then(function(cache) { cache.put(event.request, copy); });
        }
        return resp;
      }).catch(function() { return cached; });
      return cached || fetchPromise;
    })
  );
});