// ========================================
// FX Atlas PWA Service Worker
// ========================================
// 更新時は CACHE_NAME の日付/バージョンを変更してください
// ========================================

const CACHE_NAME = 'fxatlas-2026-09-17-v4';

const ASSETS = [
  './',
  './index.html',
  './manifest.json',
  './icon-192.svg',
  './icon-512.svg'
];

self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then(cache => Promise.all(
        ASSETS.map(url =>
          cache.add(url).catch(err => console.warn('[SW] キャッシュ失敗:', url, err))
        )
      ))
      .then(() => 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))
      ))
      .then(() => self.clients.claim())
  );
});

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

  const url = new URL(event.request.url);
  if (url.origin !== self.location.origin) return;

  event.respondWith(
    caches.match(event.request).then(cached => {
      if (cached) return cached;
      return fetch(event.request)
        .then(response => {
          if (response && response.status === 200 && response.type === 'basic') {
            const clone = response.clone();
            caches.open(CACHE_NAME).then(cache => cache.put(event.request, clone)).catch(() => {});
          }
          return response;
        })
        .catch(() => {
          if (event.request.mode === 'navigate') return caches.match('./index.html');
          return new Response('Offline', { status: 503 });
        });
    })
  );
});

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