const http = require('http'),
      fs = require('fs');
const { exec } = require('child_process');
const { parse } = require('querystring');

function setBrightness(display, value, res) {
  exec(`setbrightness "${value}"`, (error, stdout, stderr) => {
    if (error) {
      console.error(`exec error: ${error}`);
      return;
    }
    console.log(`stdout: ${stdout}`);
    console.log(`stderr: ${stderr}`);
    // Redirect the client back to the main page after the command has run
    res.writeHead(303, { Location: '/' });
    res.end();
  });
}

http.createServer((req, res) => {
  if (req.url.startsWith('/button_pressed?')) {
    // Parse the query string from the request URL
    const query = req.url.split('?')[1];
    // Read the brightness value from the query string
    //const brightness = query.brightness;
    // Set the brightness using the value from the slider
    setBrightness(1, query, res);
  } else if (req.url === '/') {
    // Send the form when the root URL is requested
    let item = fs.readFile('./index.html', function(err, html) {
        if (err) {
            throw err; 
        }
        else {
            res.writeHead(200, { 'Content-Type': 'text/html' });
            res.end(html);
          }
    });
  }
}).listen(5000);

console.log('Server listening on port 5000');