import * as signalR from '@microsoft/signalr'
import * as msgpack from '@microsoft/signalr-protocol-msgpack'
import mitt from 'mitt'
import router from '@/router'

export const emitter = mitt()
let connection = null

// 注册消息处理函数
function registerHandlers(conn) {
  conn.on('ReceiveMessage', (group, user, message) => {
    emitter.emit('ReceiveMessage', { group, user, message })
  })

  conn.on('OnlineCount', (count) => {
    emitter.emit('OnlineCount', count)
  })

  conn.on('GroupCount', (groupName, count) => {
    emitter.emit('GroupCount', { groupName, count })
  })

  conn.on('SendPrivateMessage', (ResultResponse) => {
    emitter.emit('SendPrivateMessage', ResultResponse)
  })
  conn.on('SendReadReceipt', (messageId) => {
    emitter.emit('SendReadReceipt', messageId)
  })

  // 监听用户状态变化
  connection.on("UserStatusChanged", (userId, isOnline) => {
    emitter.emit('UserStatusChanged', { userId, isOnline })
  })
}

// 初始连接（不带 token）
async function createConnection() {
  connection = new signalR.HubConnectionBuilder()
    .withUrl('http://192.168.1.254:5162/Chat')
    .withHubProtocol(new msgpack.MessagePackHubProtocol())
    .withAutomaticReconnect()
    .build()

  registerHandlers(connection)
  await connection.start()
  emitter.emit('Connected') // 通知页面连接成功
  return connection
}

// 刷新 AccessToken
async function RefreshAccessToken() {
  const oldRefreshToken = localStorage.getItem('refreshToken')
  if (!oldRefreshToken) return

  connection.send('RefreshAccessToken', oldRefreshToken)

  connection.off('ReceiveNewAccessToken')
  connection.on('ReceiveNewAccessToken', async (newAccessToken, newRefreshToken) => {
    localStorage.setItem('accessToken', newAccessToken)
    localStorage.setItem('refreshToken', newRefreshToken)
    await reconnectWithToken()
  })

  connection.off('RefreshFailed')
  connection.on('RefreshFailed', (message) => {
    console.error('刷新失败:', message)
    localStorage.removeItem('accessToken')
    localStorage.removeItem('refreshToken')
    router.push('/')
  })
}

// 使用新的 token 重建连接
async function reconnectWithToken() {
  const accessToken = localStorage.getItem('accessToken')
  if (!accessToken) return

  if (connection) {
    await connection.stop()
  }

  connection = new signalR.HubConnectionBuilder()
    .withUrl(`http://192.168.1.254:5162/Chat?access_token=${accessToken}`)
    .withHubProtocol(new msgpack.MessagePackHubProtocol())
    .withAutomaticReconnect()
    .build()

  registerHandlers(connection)
  await connection.start()
  emitter.emit('Connected') // 通知页面连接成功
}

// 页面加载时自动执行
;(async () => {
  await createConnection()
  await RefreshAccessToken() // 尝试刷新 token 并重连
})()

export { connection, reconnectWithToken, createConnection }