// 使用這個庫可以添加的請求頭（比如添加token）
import { EventSourcePolyfill } from "event-source-polyfill";
import { getToken } from '@/utils/user'
export default {
  data() {
    return {
      eventSource: null
    }
  },
  mounted() {
    this.createSSE()
  },
  methods: {
    createSSE(){
      if(window.EventSource){
        // 根據(jù)環(huán)境的不同，變更url
        const url = process.env.VUE_APP_MSG_SERVER_URL
        // 用戶userId
        const { userId } = this.$store.state.user
        this.eventSource = new EventSourcePolyfill(
          `${url}/sse/connect/${userId}`, {
          // 設置重連時間
          heartbeatTimeout: 60 * 60 * 1000,
          // 添加token
          headers: {
             'Authorization': `Bearer ${getToken()}`,
          },
        });
        this.eventSource.onopen = (e) => {
          console.log("已建立SSE連接~")
        }
        this.eventSource.onmessage = (e) => {
          console.log("已接受到消息:", e.data)
        }
        this.eventSource.onerror = (e) => {
          if (e.readyState == EventSource.CLOSED) {
            console.log("SSE連接關閉");
          } else if (this.eventSource.readyState == EventSource.CONNECTING) {
            console.log("SSE正在重連");
            //重新設置token
            this.eventSource.headers = {
              'Authorization': `Bearer ${getToken()}`
            };
          } else {
            console.log('error', e);
          }
        };
      } else {
        console.log("你的瀏覽器不支持SSE~")
      }
    },
    beforeDestroy() {
      if(this.eventSource){
          const { userId } = this.$store.state.user
          // 關閉SSE
          this.eventSource.close();
          // 通知后端關閉連接
          this.$API.system.msg.closeSse(userId)
          this.eventSource = null
          console.log("退出登錄或關閉瀏覽器，關閉SSE連接~")
       }
    },