const express = require('express')
const WebSocket = require('ws')
const { v4: uuidv4 } = require('uuid')

const app = express()
const server = require('http').createServer(app)
const wss = new WebSocket.Server({ server })

let userId = 0
let onlineUsers = {}

wss.on('connection', ws => {
  ws.id = uuidv4() // 为每个连接分配一个唯一的 ID

  ws.on('message', message => {
    let user = JSON.parse(message)
    user.id = ++userId
    onlineUsers[ws.id] = user // 用户上线，添加到在线用户列表
  })

  ws.on('close', () => {
    delete onlineUsers[ws.id] // 用户下线，从在线用户列表中移除
  })
})

app.get('/heartbeat', (req, res) => {
  console.log('Heartbeat', req.query)
})

// 每隔5秒打印在线用户
setInterval(() => {
  console.log(new Date())
  console.log('Online users:', onlineUsers)
}, 5000)

server.listen(3000, () => {
  console.log('WebSocket server listening on port 3000')
})