sw.js

const CACHE_NAME = 'macro-tracker-2026-10-08.1';
const APP_VERSION = '2026-10-08.1';
const STATIC_ASSETS = [
  '/',
  '/index.html',
  '/manifest.json',
  '/icon-192.svg',
  '/icon-512.svg'
];

self.addEventListener('install', e => {
  e.waitUntil(
    caches.open(CACHE_NAME).then(cache => cache.addAll(STATIC_ASSETS))
  );
  self.skipWaiting(); // activate immediately, don't wait for tabs to close
});

self.addEventListener('activate', e => {
  e.waitUntil(
    caches.keys().then(keys =>
      Promise.all(keys.filter(k => k !== CACHE_NAME).map(k => caches.delete(k)))
    ).then(() => self.clients.claim()) // take control of all open pages
  );
});

self.addEventListener('fetch', e => {
  const url = new URL(e.request.url);

  // Never intercept docs pages — let them load fresh from the network
  if (url.pathname.startsWith('/docs/')) {
    return;
  }

  // Network-first for Open Food Facts API and USDA
  if (url.hostname.includes('api.nal.usda.gov')) {
    e.respondWith(
      fetch(e.request)
        .then(res => {
          const clone = res.clone();
          caches.open(CACHE_NAME).then(cache => cache.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request))
    );
    return;
  }

  if (url.hostname.includes('openfoodfacts.org')) { // covers en., uk., world., etc.
    e.respondWith(
      fetch(e.request)
        .then(res => {
          const clone = res.clone();
          caches.open(CACHE_NAME).then(cache => cache.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request))
    );
    return;
  }

  // Cache-first for ZXing CDN
  if (url.hostname === 'unpkg.com') {
    e.respondWith(
      caches.match(e.request).then(cached => {
        if (cached) return cached;
        return fetch(e.request).then(res => {
          const clone = res.clone();
          caches.open(CACHE_NAME).then(cache => cache.put(e.request, clone));
          return res;
        });
      })
    );
    return;
  }

  // Network-first for the main HTML so updates are always picked up
  if (url.pathname.endsWith('/') || url.pathname.endsWith('index.html')) {
    e.respondWith(
      fetch(e.request)
        .then(res => {
          const clone = res.clone();
          caches.open(CACHE_NAME).then(cache => cache.put(e.request, clone));
          return res;
        })
        .catch(() => caches.match(e.request))
    );
    return;
  }

  // Cache-first for everything else (icons, manifest)
  e.respondWith(
    caches.match(e.request).then(cached => cached || fetch(e.request))
  );
});