const CACHE = 'v1';
const LOGIN = '/login.html';
const EXPIRE_MS = 3 * 60 * 60 * 1000; // 3小时

self.addEventListener('install', () => self.skipWaiting());

self.addEventListener('activate', e => e.waitUntil(self.clients.claim()));

self.addEventListener('fetch', e => {
  const req = e.request;
  if (req.url.includes('/login.html') || req.url.includes('/auth/')) {
    e.respondWith(fetch(req));
    return;
  }

  e.respondWith((async () => {
    const token = self.__auth_token;
    const tokenTime = self.__auth_time || 0;

    if (!token || (Date.now() - tokenTime > EXPIRE_MS)) {
      // token 过期或不存在，重定向到登录页
      if (token) {
        self.__auth_token = null;
        self.__auth_time = 0;
      }
      return Response.redirect(LOGIN, 302);
    }

    const headers = new Headers(req.headers);
    headers.set('Authorization', 'Basic ' + token);
    const res = await fetch(new Request(req, { headers }));

    if (res.status === 401) {
      self.__auth_token = null;
      self.__auth_time = 0;
      return Response.redirect(LOGIN, 302);
    }
    return res;
  })());
});

// 接收页面发来的 token
self.addEventListener('message', e => {
  if (e.data && e.data.type === 'SET_TOKEN') {
    self.__auth_token = e.data.token;
    self.__auth_time = Date.now();
  }
  if (e.data && e.data.type === 'CLEAR_TOKEN') {
    self.__auth_token = null;
    self.__auth_time = 0;
  }
});