index.js

// Setup basic express server
var express = require('express');
var app = express();
var path = require('path');
var server = require('http').createServer(app);
var io = require('socket.io')(server);
var port = process.env.PORT || 3001;
const pd = require('paralleldots');
pd.apiKey = 'CslqOaTfQnQ0SY8fO2suPrFlnGjH1TH75Tfp3TtL9yA';



server.listen(port, () => {
    console.log('Server listening at port %d', port);
});

// Routing
app.use(express.static(path.join(__dirname, 'public')));

// Chatroom
var numUsers = 0;

io.on('connection', (socket) => {
    var addedUser = false;
    let responseOuter;

    // when the client emits 'new message', this listens and executes
    socket.on('new message', (data) => {
        // we tell the client to execute 'new message'

        pd.emotion(data,"en")
            .then((response) => {
                console.log(response);
                responseOuter = response;
            })
            .then((e) => {
                socket.broadcast.emit('intent change', data, responseOuter);
            })
            .catch((error) => {
                console.log(error);
            });

        socket.broadcast.emit('new message', {
            username: socket.username,
            message: data
        });
    });

    socket.on('new intent', (message, intent) => {
        socket.broadcast.emit('intent change', message, intent);
    });

    // when the client emits 'add user', this listens and executes
    socket.on('add user', (username) => {
        if (addedUser) return;

        // we store the username in the socket session for this client
        socket.username = username;
        ++numUsers;
        addedUser = true;
        socket.emit('login', {
            numUsers: numUsers
        });
        // echo globally (all clients) that a person has connected
        socket.broadcast.emit('user joined', {
            username: socket.username,
            numUsers: numUsers
        });
    });

    // when the client emits 'typing', we broadcast it to others
    socket.on('typing', () => {
        socket.broadcast.emit('typing', {
            username: socket.username
        });
    });

    // when the client emits 'stop typing', we broadcast it to others
    socket.on('stop typing', () => {
        socket.broadcast.emit('stop typing', {
            username: socket.username
        });
    });

    // when the user disconnects.. perform this
    socket.on('disconnect', () => {
        if (addedUser) {
            --numUsers;

            // echo globally that this client has left
            socket.broadcast.emit('user left', {
                username: socket.username,
                numUsers: numUsers
            });
        }
    });
});