'use strict';
// v2: card faces are now precached so they never flash or refetch mid-game
const CACHE_NAME = 'hearts-v2';

// ── All 52 card faces ───────────────────────────────────────────
const SUITS = ['CLUB', 'DIAMOND', 'HEART', 'SPADE'];
const CARD_PATHS = SUITS.flatMap(s => [
  `/cards/${s}-1.svg`,
  `/cards/${s}-2.svg`,
  `/cards/${s}-3.svg`,
  `/cards/${s}-4.svg`,
  `/cards/${s}-5.svg`,
  `/cards/${s}-6.svg`,
  `/cards/${s}-7.svg`,
  `/cards/${s}-8.svg`,
  `/cards/${s}-9.svg`,
  `/cards/${s}-10.svg`,
  `/cards/${s}-11-JACK.svg`,
  `/cards/${s}-12-QUEEN.svg`,
  `/cards/${s}-13-KING.svg`,
]);

const SHELL = [
  '/',
  '/index.html',
  '/style.css',
  '/app.js',
  '/manifest.json',
  '/icons/icon-192.png',
  '/icons/icon-512.png',
  '/icons/icon.svg',
];

self.addEventListener('install', event => {
  event.waitUntil((async () => {
    const cache = await caches.open(CACHE_NAME);
    // The shell must land; a missing card shouldn't abort the whole install
    await cache.addAll(SHELL);
    await Promise.all(CARD_PATHS.map(p => cache.add(p).catch(() => {})));
  })());
  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 => {
  const url = event.request.url;
  if (event.request.method !== 'GET') return;
  if (url.includes('/socket.io/')) return;

  // Cards never change — always cache-first, and never go to the network again
  // once we hold a copy.
  if (url.includes('/cards/')) {
    event.respondWith(
      caches.match(event.request).then(cached => cached || fetch(event.request).then(res => {
        const copy = res.clone();
        caches.open(CACHE_NAME).then(c => c.put(event.request, copy));
        return res;
      }))
    );
    return;
  }

  // Everything else: network-first, cache as the offline fallback
  event.respondWith(
    fetch(event.request)
      .then(res => {
        const copy = res.clone();
        caches.open(CACHE_NAME).then(c => c.put(event.request, copy));
        return res;
      })
      .catch(() => caches.match(event.request))
  );
});