/* 简易 Service Worker：缓存静态资源，支持离线访问与 PWA 安装 */
const CACHE_NAME = 'dms-cache-v1';
const STATIC_ASSETS = [
  '/',
  '/index.html',
  '/manifest.webmanifest',
  '/assets/logo-icon.png',
  '/assets/logo-white.png',
  '/assets/logo-dark.png'
];

// 安装阶段：预缓存静态资源
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => cache.addAll(STATIC_ASSETS))
  );
  self.skipWaiting();
});

// 激活阶段：清理旧缓存
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();
});

// 请求阶段：API 走网络，静态资源优先缓存
self.addEventListener('fetch', (event) => {
  const url = new URL(event.request.url);

  // API 请求不缓存
  if (url.pathname.startsWith('/api')) return;

  event.respondWith(
    caches.match(event.request).then((cached) => {
      if (cached) return cached;
      return fetch(event.request).then((response) => {
        // 只缓存同源 GET 静态资源
        if (event.request.method === 'GET' && url.origin === self.location.origin) {
          const clone = response.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
        }
        return response;
      });
    }).catch(() => caches.match('/index.html'))
  );
});