const CACHE_NAME = 'emailbill-v1';
const urlsToCache = [
  '/',
  '/index.html',
  '/favicon.ico',
  '/manifest.json'
];

// 安装 Service Worker
self.addEventListener('install', (event) => {
  console.log('[Service Worker] 安装中...');
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then((cache) => {
        console.log('[Service Worker] 缓存文件');
        return cache.addAll(urlsToCache);
      })
  );
});

// 监听跳过等待消息
self.addEventListener('message', (event) => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});

// 激活 Service Worker
self.addEventListener('activate', (event) => {
  console.log('[Service Worker] 激活中...');
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.map((cacheName) => {
          if (cacheName !== CACHE_NAME) {
            console.log('[Service Worker] 删除旧缓存:', cacheName);
            return caches.delete(cacheName);
          }
        })
      );
    }).then(() => self.clients.claim())
  );
});

// 拦截请求
self.addEventListener('fetch', (event) => {
  const { request } = event;
  const url = new URL(request.url);

  // 跳过跨域请求
  if (url.origin !== location.origin) {
    return;
  }

  // API请求使用网络优先策略
  if (url.pathname.startsWith('/api/')) {
    event.respondWith(
      fetch(request)
        .then((response) => {
          // 克隆响应以便缓存
          const responseClone = response.clone();
          caches.open(CACHE_NAME).then((cache) => {
            cache.put(request, responseClone);
          });
          return response;
        })
        .catch(() => {
          // 网络失败时尝试从缓存获取
          return caches.match(request);
        })
    );
    return;
  }

  // 静态资源使用缓存优先策略
  event.respondWith(
    caches.match(request)
      .then((response) => {
        if (response) {
          return response;
        }
        return fetch(request).then((response) => {
          // 检查是否是有效响应
          if (!response || response.status !== 200 || response.type !== 'basic') {
            return response;
          }

          const responseClone = response.clone();
          caches.open(CACHE_NAME).then((cache) => {
            cache.put(request, responseClone);
          });

          return response;
        });
      })
      .catch(() => {
        // 返回离线页面或默认内容
        if (request.destination === 'document') {
          return caches.match('/index.html');
        }
      })
  );
});

// 后台同步
self.addEventListener('sync', (event) => {
  console.log('[Service Worker] 后台同步:', event.tag);
  if (event.tag === 'sync-data') {
    event.waitUntil(syncData());
  }
});

// 推送通知
self.addEventListener('push', (event) => {
  console.log('[Service Worker] 收到推送消息');
  let data = { title: '账单管理', body: '您有新的消息', url: '/', icon: '/icons/icon-192x192.png' };
  
  if (event.data) {
    try {
      const json = event.data.json();
      data = { ...data, ...json };
    } catch {
      data.body = event.data.text();
    }
  }

  const options = {
    body: data.body,
    icon: data.icon,
    badge: '/icons/icon-72x72.png',
    vibrate: [200, 100, 200],
    tag: 'emailbill-notification',
    requireInteraction: false,
    data: { url: data.url }
  };

  event.waitUntil(
    self.registration.showNotification(data.title, options)
  );
});

// 通知点击
self.addEventListener('notificationclick', (event) => {
  console.log('[Service Worker] 通知被点击');
  event.notification.close();
  const urlToOpen = event.notification.data?.url || '/';
  event.waitUntil(
    clients.matchAll({ type: 'window', includeUncontrolled: true }).then((windowClients) => {
      // 如果已经打开了该 URL，则聚焦
      for (let i = 0; i < windowClients.length; i++) {
        const client = windowClients[i];
        if (client.url === urlToOpen && 'focus' in client) {
          return client.focus();
        }
      }
      // 否则打开新窗口
      if (clients.openWindow) {
        return clients.openWindow(urlToOpen);
      }
    })
  );
});

// 数据同步函数
async function syncData() {
  try {
    // 这里添加需要同步的逻辑
    console.log('[Service Worker] 执行数据同步');
  } catch (error) {
    console.error('[Service Worker] 同步失败:', error);
  }
}