Integrating with Express.js & Socket.io

app.js

@@ -1,34 +1,29 @@
 const { Client } = require('whatsapp-web.js');
-const qrcode = require('qrcode-terminal');
+const express = require('express');
+const socketIO = require('socket.io');
+const qrcode = require('qrcode');
+const http = require('http');
 const fs = require('fs');
 
+const app = express();
+const server = http.createServer(app);
+const io = socketIO(server);
+
+app.use(express.json());
+app.use(express.urlencoded({ extended: true }));
+
 const SESSION_FILE_PATH = './whatsapp-session.json';
 let sessionCfg;
 if (fs.existsSync(SESSION_FILE_PATH)) {
     sessionCfg = require(SESSION_FILE_PATH);
 }
 
+app.get('/', (req, res) => {
+    res.sendFile('index.html', { root: __dirname });
+});
+
 const client = new Client({ puppeteer: { headless: true }, session: sessionCfg });
 
-client.on('qr', (qr) => {
-    console.log('QR RECEIVED', qr);
-    qrcode.generate(qr);
-});
-
-client.on('authenticated', (session) => {
-    console.log('AUTHENTICATED', session);
-    sessionCfg=session;
-    fs.writeFile(SESSION_FILE_PATH, JSON.stringify(session), function (err) {
-        if (err) {
-            console.error(err);
-        }
-    });
-});
-
-client.on('ready', () => {
-    console.log('Client is ready!');
-});
-
 client.on('message', msg => {
     if (msg.body == '!ping') {
         msg.reply('pong');
@@ -37,4 +32,56 @@ client.on('message', msg => {
     }
 });
 
-client.initialize();
+client.initialize();
+
+// Socket IO
+io.on('connection', function(socket) {
+    socket.emit('message', 'Connecting...');
+
+    client.on('qr', (qr) => {
+        console.log('QR RECEIVED', qr);
+        qrcode.toDataURL(qr, (err, url) => {
+            socket.emit('qr', url);
+            socket.emit('message', 'QR Code received, scan please!');
+        });
+    });
+
+    client.on('ready', () => {
+        socket.emit('ready', 'Whatsapp is ready!');
+        socket.emit('message', 'Whatsapp is ready!');
+    });
+
+    client.on('authenticated', (session) => {
+        socket.emit('authenticated', 'Whatsapp is authenticated!');
+        socket.emit('message', 'Whatsapp is authenticated!');
+        console.log('AUTHENTICATED', session);
+        sessionCfg=session;
+        fs.writeFile(SESSION_FILE_PATH, JSON.stringify(session), function (err) {
+            if (err) {
+                console.error(err);
+            }
+        });
+    });
+});
+
+// Send message
+app.post('/send-message', (req, res) => {
+    const number = req.body.number;
+    const message = req.body.message;
+
+    client.sendMessage(number, message).then(response => {
+        res.status(200).json({
+            status: true,
+            response: response
+        });
+    }).catch(err => {
+        res.status(500).json({
+            status: false,
+            response: err
+        });
+    });
+});
+
+server.listen(8000, function() {
+    console.log('App running on *: ' + 8000);
+});