feat: add data generation logic and history file class

backend/index.js

@@ -1,8 +1,15 @@
-const WebSocket = require('ws');
+import { WebSocketServer } from 'ws';
+import HistoryFile from './classes/HistoryFile.js';
 
-const wss = new WebSocket.Server({ port: 8080 });
+// Define WebSocket server
+const wss = new WebSocketServer({ port: 8080 });
+// Define History file class
+// For managing data state beyond restart
+const history = new HistoryFile('data.json');
 
 wss.on('connection', (ws) => {
+  // On successful connection, we send history data to the client
+  // After that, we procceed sending data update every 10 seconds
   console.log('Client connected');
 
   ws.on('message', (message) => {