// Service Worker for PWA
const CACHE_NAME = 'qingyuan-erp-v1';
const STATIC_ASSETS = [
  '/',
  '/index.html',
  '/manifest.json',
  '/logo.png'
];

// 安装时缓存静态资源
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      return cache.addAll(STATIC_ASSETS);
    }).catch((err) => {
      console.log('Cache failed:', err);
    })
  );
  self.skipWaiting();
});

// 激活时清理旧缓存
self.addEventListener('activate', (event) => {
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames
          .filter((name) => name !== CACHE_NAME)
          .map((name) => caches.delete(name))
      );
    })
  );
  self.clients.claim();
});

// 拦截请求，优先使用缓存
self.addEventListener('fetch', (event) => {
  // 跳过非GET请求和API请求
  if (event.request.method !== 'GET' || 
      event.request.url.includes('/api/') ||
      event.request.url.includes('chrome-extension')) {
    return;
  }

  event.respondWith(
    caches.match(event.request).then((response) => {
      // 如果缓存中有，返回缓存
      if (response) {
        return response;
      }

      // 否则发起网络请求
      return fetch(event.request).then((networkResponse) => {
        // 缓存新请求
        if (networkResponse.status === 200) {
          const responseToCache = networkResponse.clone();
          caches.open(CACHE_NAME).then((cache) => {
            cache.put(event.request, responseToCache);
          });
        }
        return networkResponse;
      }).catch(() => {
        // 网络失败时返回离线页面
        if (event.request.mode === 'navigate') {
          return caches.match('/index.html');
        }
      });
    })
  );
});