Send message synchronously with Nodejs Websocket - node.js

Question

My app has three modules:
WebSocket Module: resides on the remote server (internet) and it acts as a Websocket
server that entertain the connection between Client Module and
Webhook module.
Webhook Module: resides on the remote server (internet) and it acts as
a webhook to answer the HTTP post request from the user. It is connected to Websocket Module via websocket as well.
Client Module: resides on my local machine and it is connected to
the
Webhook model via websocket. This client responsible to get query
from my local backend.
When a user call Webhook Module through HTTP Post request, Webhook module initiate a connection to WebSocket module via websocket. Then, the WebSocket module initiate the connection to Client module and response back with the necessary information. Actually I have to do this to eliminate the HTTP tunnel that is blocked in my company.
The problem is, when I open two browser windows to perform the HTTP Post request at the same time with different parameter, for example, param "A", I would expect to get return "A", with param "B", I expect to get "B" not "A". But There is something wrong with my codes/design. If I executed at the same time, I throw "A" then I got "B" which is wrong. How do I overcome this.
This is a simple diagram to illustrate it.
WebSocket Module:
'use strict'
//This is WebSocket Server
const clients = {};
const SocketIO = require('socket.io');
const express = require('express');
const http = require('http');
const app = express();
const server = http.createServer(app);
const ws = SocketIO(server);
const port = 3000;
var clientid;
ws.on('connection', (client) => {
clients[client.id] = client;
console.log('new connection', client.id);
clientid = client.id;
client.emit('message', { message: 'welc' })
client.on('disconnect', () => {
delete clients[client.id];
console.log('Client ' + client.id + ' disconnected. Deleted');
});
client.on('WH', function (from, msg) {
console.log('Message from Webhook', from, ' : ', msg);
client.broadcast.emit('message', { message: msg });
//console.log('send to: ' + clientid);
//ws.to(clientid).emit('hey', { message: msg });
//client.emit('message', { message: msg })
});
client.on('CL', function (from, msg) {
console.log('Message from Client', from, ' : ', msg);
client.broadcast.emit('message', 'me', msg);
//ws.to(client.id).emit('message', 'me', msg);
//client.emit('message', 'me', msg);
});
});
server.listen(process.env.PORT || port);
console.log('WebSocket Server is running on port ' + port);
Webhook Module
'use strict'
//This is WebHook Server
const express = require('express');
const bodyParser = require('body-parser');
const request = require('request');
const http = require('http');
const io = require('socket.io-client');
const app = express()
app.use(bodyParser.json())
const clients = {};
const SocketIO = require('socket.io');
const server = http.createServer(app);
const ws = SocketIO(server);
const port = 5000;
let Res;
let httpreq = false;
let nctid;
let ts;
const socket = io.connect('http://localhost:3000', {reconnect: true});
// Add a connect listener
socket.on('connect', function() {
console.log('Connected to WebSocket server!');
});
socket.on('message', function(from, msg) {
//console.log('Message from ', from, ' : ', msg);
console.log('nctid: ' + nctid + ', ts: ' + ts);
//Get the message from Client
if (httpreq) {
Res.send({
replies: [{
type: 'text',
content: msg,
}],
conversation: {
memory: {
key: msg
}
}
})
httpreq = false;
}
});
app.listen(process.env.PORT || port, () => {
console.log('Webhook server is running on port ' + port);
})
app.post('/', (req, res) => {
//console.log(req.body)
let query = req.body.nlp.entities.query[0].value;
nctid = req.body.nlp.entities.nctid[0].value;
ts = Math.floor(Date.now() / 1000);
console.log("query: " + query + '|' + nctid + '|' + ts);
//Send message to WebSocket server with parameter query and NCTID
socket.emit('WH', 'me', query + '|' + nctid);
Res = res;
httpreq = true;
})
app.post('/errors', (req, res) => {
console.log(req.body);
res.send();
})
Client Module
'use strict'
//This is client app running on client premise
const request = require('request');
const parser = require('xml2json');
const io = require('socket.io-client');
const socket = io.connect('http://localhost:3000', {reconnect: true});
// Add a connect listener
socket.on('connect', function(socket) {
console.log('Connected to WebSocket server!');
});
socket.on('message', function(from, msg) {
//console.log('MSG', from, ' : ', msg);
console.log(from);
let param = from.message.split('|');
let query = param[0];
let nctid = param[1];
if (typeof nctid != 'undefined') {
getNCTID(nctid, function(returnValue) {
//console.log(returnValue);
try {
let json = parser.toJson(returnValue);
json = JSON.parse(json);
if (query == 'title')
socket.emit('CL', 'me', 'Title is ' + json.clinical_study.brief_title);
else
socket.emit('CL', 'me', 'Status is ' + json.clinical_study.overall_status);
} catch (e) {
console.log(e);
socket.emit('CL', 'me', 'No NCTID ' + nctid);
}
});
}
});
function getNCTID(nctid, callback) {
let url = "https://clinicaltrials.gov/ct2/show/" + nctid + "?displayxml=true";
let options = {
url: url,
method: 'GET'
}
//console.log(options);
let requestWithEncoding = function(options, callback) {
let req = request.get(options);
req.on('response', function(res) {
let chunks = [];
res.on('data', function(chunk) {
chunks.push(chunk);
});
res.on('end', function() {
let buffer = Buffer.concat(chunks);
let encoding = res.headers['content-encoding'];
if (encoding == 'gzip') {
zlib.gunzip(buffer, function(err, decoded) {
callback(err, decoded && decoded.toString());
});
} else if (encoding == 'deflate') {
zlib.inflate(buffer, function(err, decoded) {
callback(err, decoded && decoded.toString());
})
} else {
callback(null, buffer.toString());
}
});
});
req.on('error', function(err) {
callback(err);
});
}
requestWithEncoding(options, function(err, data) {
if (err) {
console.log('err:' + err);
callback('error');
} else
//console.log(data);
callback(data);
})
}