// Service Worker版本，用于缓存更新
const CACHE_VERSION = 'v1';
const CACHE_NAME = `vip-video-cache-${CACHE_VERSION}`;

// 需要缓存的静态资源
const urlsToCache = [
  '/',
  '/index.html',
  '/manifest.json',
  '/icons/icon-192x192.png',
  '/icons/icon-512x512.png'
];

// 安装Service Worker
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then((cache) => {
        console.log('已打开缓存');
        return cache.addAll(urlsToCache);
      })
      .then(() => self.skipWaiting())
  );
});

// 激活Service Worker
self.addEventListener('activate', (event) => {
  const cacheWhitelist = [CACHE_NAME];
  
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.map((cacheName) => {
          if (cacheWhitelist.indexOf(cacheName) === -1) {
            return caches.delete(cacheName);
          }
        })
      );
    }).then(() => self.clients.claim())
  );
});

// 拦截网络请求
self.addEventListener('fetch', (event) => {
  // 跳过非GET请求和非http/https请求
  if (event.request.method !== 'GET' || 
      !event.request.url.startsWith('http')) {
    return;
  }
  
  // 跳过解析接口请求
  if (event.request.url.includes('jx.xmflv.com') || 
      event.request.url.includes('/api/')) {
    return;
  }
  
  event.respondWith(
    caches.match(event.request)
      .then((response) => {
        // 如果在缓存中找到响应，则返回缓存的响应
        if (response) {
          return response;
        }
        
        // 否则发起网络请求
        return fetch(event.request).then(
          (response) => {
            // 检查是否收到有效的响应
            if (!response || response.status !== 200 || response.type !== 'basic') {
              return response;
            }
            
            // 克隆响应，因为响应是流，只能使用一次
            const responseToCache = response.clone();
            
            caches.open(CACHE_NAME)
              .then((cache) => {
                // 忽略查询参数的URL
                const urlWithoutQuery = event.request.url.split('?')[0];
                cache.put(event.request, responseToCache);
              });
            
            return response;
          }
        );
      }).catch(() => {
        // 如果请求失败且没有缓存，返回离线页面
        if (event.request.mode === 'navigate') {
          return caches.match('/');
        }
      })
  );
});