TypeError: io.emit is not a function

i have declared the io in the index.js file ( main file. and i want to emit the updates to the client inside the controllers/devices.js. but on testing it is is giving

TypeError: io.emit is not a function
    at handleUpdateDevice (/home/parthkamal/Documents/development/tekuncorked-server/controllers/device.js:84:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
(node:98489) Warning: Accessing non-existent property 'emit' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)
node:internal/errors:496
    ErrorCaptureStackTrace(err);
    ^

controllers/devices.js

const Device = require('../models/device');
const io = require('../index');

// other functions

const handlePostDevice = async (request, response) => {



    try {

        const { name, location, temperature } = request.body;

        console.log(request.body);


        console.log({ name, location, temperature });
        const newDevice = new Device({ name, location, temperature });

        await newDevice.save();

        response.status(200).json({ message: "device added successfully" });
        const devices = await Device.find();
        io.emit('data-created', { devices });

    } catch (error) {

        console.log(error);
        response.status(400).json({ error });
    }

}

const handleUpdateDevice = async (request, response) => {

    try {

        const { id } = request.params;
        const updates = request.body;
        console.log(updates);
        await Device.findByIdAndUpdate(id, updates);
        response.status(200).json({ message: "updated successfully" }); 

        const devices = await getDevices();
        io.emit('data-updated', { devices });

    } catch (error) {


        console.log(error);
        response.status(400).json({ error });
    }

}



module.exports = {
    getDevices,
    handleGetDevices,
    handleGetDevicesById,
    handlePostDevice, 
    handleUpdateDevice 
}

my directory structure is like this

index.js

const express = require('express');
const http = require('http');
const cors = require('cors');
const dotenv = require('dotenv');
const { getDevices } = require('./controllers/device')
const createDbConnection = require('./db');
const socketIo = require('socket.io');

const app = express();
const server = http.createServer(app);

const io = socketIo(server, {
  cors: {
    origin: "http://localhost:3000",
  }
});

dotenv.config();
const PORT = process.env.PORT;

const corsOptions = {
  origin: 'http://localhost:3000',
};


//middlewares
app.use(cors(corsOptions));
app.use(express.json());


//routes
const deviceRoute = require('./routes/device');
app.use('/device', deviceRoute);

io.on('connection', async (socket) => {
  console.log(`user with socket id ${socket.id} is connected`);

  try {
    const devices = await getDevices();
    socket.emit('data', { devices });

  } catch (error) {
    console.log('connection ke dauran devices fetch karne me error agya');
  }




  socket.on('disconnect', () => {
    console.log('a user got disconnected');
  });
});

//db connection
createDbConnection();

app.get('/', (req, res) => {
  res.send('hello from the tekuncorked server');
});

server.listen(PORT, () => {
  console.log(`server is listening on port ${PORT}`);
});

module.exports = io;

i think there is a problem in exporting the io module. to the controller. how can I achieve that?