const ws = require('ws')
const webtoken = require('wo-base-webtoken')

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

module.exports = {
  initSocket (webServer) {
    my.wsServer = new ws.Server({ server: webServer })
    console.info(new Date().toJSON(), '[LOG] Base Socket Server is initialized.')

    my.wsServer.on('connection', (socket, req) => {
      //console.info(new Date().toJSON(), `[LOG] A socket is connecting from ${req.connection.remoteAddress}:${req.connection.remotePort}.`)

      // socket.isAlive = true
      // socket.on('pong', function() { this.isAlive = true })

      socket.on('message', (data) => {
        // 在这里统一分发消息
        let dataObj
        try {
          dataObj = JSON.parse(data)
          console.log(new Date().toJSON(), '[LOG] 收到 App Socket Event: ', dataObj?.skevent)
        } catch (exception) {
          console.log(new Date().toJSON(), '[LOG] Unable to parse socket message: ', data)
          return
        }
        if (['SOCKET_OWNER', 'SOCKET_OWNER_RECONNECT'].includes(dataObj.skevent)) {
          dataObj._passtokenSource = webtoken.verifyToken(dataObj._passtoken)
          if (typeof dataObj._passtokenSource?.usid === 'string') {
            my.socketPool[dataObj._passtokenSource.usid] = socket
            socket.usid = dataObj._passtokenSource.usid
            console.log(
              new Date().toJSON(), '[LOG]',
              dataObj.skevent === 'SOCKET_OWNER' ? 'Login' : 'Reconnect',
              '绑定 socket 到',
              dataObj._passtokenSource.usid,
              'socketPool.length =',
              Object.keys(my.socketPool)?.length,
              ', socket clients size =',
              my.wsServer.clients.size
            )
          }
        }

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

      // const heartbeat = setInterval(() => {
      //   my.wsServer.clients.forEach((socket) => {
      //     if (socket.isAlive === false) return socket.terminate()
      //     socket.isAlive = false
      //     socket.ping(function() { wo.cclog('👉 ASS: sent Ping') })
      //   })
      // }, 60000)

      socket.on('close', () => {
        //console.log(new Date().toJSON(), '[LOG] Closing socket of usid =', socket?.usid) // don't know why, but this output happens too often without usid.
        delete my.socketPool[socket?.usid]
        // clearInterval(heartbeat)
      })
    })

    return this
  },

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

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

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

// 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。