const ws = require('ws')
const webtoken = require('basend-webtoken')

const my = {
  wssServer: undefined,
  socketPool: {},
  listeners: {},
}

module.exports = {
  initSocket (webServer) {
    my.wssServer = new ws.Server({ server: webServer })
    console.info('App Socket Server attached to web server.')

    my.wssServer.on('connection', (socket, req) => {
      console.info(`A socket from App Client is connected from ${req.connection.remoteAddress}:${req.connection.remotePort}.`)

      // socket.isAlive = true
      // socket.on('pong', function() { console.log('👈 ASS: on Pong'); this.isAlive = true })

      socket.on('message', (data) => {
        // 在这里统一分发消息
        console.log('App Socket Client message: ', data)
        let dataObj
        try {
          dataObj = JSON.parse(data)
        } catch (exception) {
          console.log(new Date().toJSON(), 'Unable to parse socket message: ', data)
          return
        }
        if (dataObj.skevent === 'SOCKET_OWNER') {
          dataObj._passtokenSource = webtoken.verifyToken(dataObj._passtoken) // todo: 为防止前端欺骗，应当用和login里类似的方法来检查来检查
          if (typeof dataObj._passtokenSource?.uuid === 'string') {
            my.socketPool[dataObj._passtokenSource.uuid] = socket
            console.log('收到Login 成功的消息，绑定socket', Object.keys(my.socketPool))
          }
        }

        const listeners = my.listeners[dataObj.skevent] || []
        for (const listener of listeners) {
          listener(dataObj)
        }
      })
    })

    return this
  },

  removeUserSocket (uuid) {
    delete my.socketPool[uuid]
  },

  addListener (skevent, listener) {
    if (Array.isArray(my.listeners[skevent]) && typeof listener === 'function') {
      my.listeners[skevent].push(listener)
    } else {
      my.listeners[skevent] = [listener]
    }
    return this
  },

  sendToAll (dataObj) {
    my.wssServer.clients.forEach((socket) => {
      if (socket.readyState === socket.OPEN) {
        socket.send(typeof dataObj !== 'string' ? JSON.stringify(dataObj) : dataObj)
      } else {
        delete my.socketPool[socket.uuid]
      }
    })
  },

  sendToOne (dataObj, uuid) {
    const socket = my.socketPool[uuid]
    if (socket && socket.readyState === socket.OPEN) {
      socket.send(typeof dataObj !== 'string' ? JSON.stringify(dataObj) : dataObj)
    } else {
      delete my.socketPool[uuid]
    }
  },
}

// todo: 前端断线重连时，并不会再次 login_success。也许在前端的initSocket时，应当把_passtoken送过来，而后台则对_passtoken做验证后再加socketPool。