const express = require('express');
const path = require('path');
const http = require('http');
const WebSocket = require('ws');
const fs = require('fs');

const app = express();
const PORT = 3000;

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

const server = http.createServer(app);
const wss = new WebSocket.Server({ server });

wss.on('connection', (ws, req) => {
    const endpoint = req.url;

    if (endpoint === '/handler1') {
        const interval = setInterval(() => {
            try {
                const data = fs.readFileSync('/dev/shm/1.txt', 'utf8').trim();
                ws.send(data);
            } catch (e) {
                ws.send('0');
            }
        }, 50); // sends every 50ms = 20 times per second

        ws.on('close', () => {
            clearInterval(interval); // cleanup when client disconnects
        });
    }

    // if (endpoint === '/handler2') {
    //     const interval = setInterval(() => {
    //         try {
    //             const data = fs.readFileSync('/dev/shm/2.txt', 'utf8').trim();
    //             ws.send(data);
    //         } catch (e) {
    //             ws.send('0');
    //         }
    //     }, 50);
    //     ws.on('close', () => clearInterval(interval));
    // }
});

server.listen(PORT, () => {
    console.log(`Server running at http://localhost:${PORT}`);
});