const express = require('express');
const { body, sanitizeBody, validationResult } = require('express-validator');

const app = express();

app.use(express.json());

// Define a route handler that uses request validation middleware
app.post('/register',
  body('username').trim().isLength({ min: 3, max: 30 })
    .withMessage('Username must be between 3 and 30 characters long')
    .escape(),
  body('email').trim().isEmail()
    .withMessage('Please enter a valid email address')
    .normalizeEmail(),
  body('password').isLength({ min: 6 })
    .withMessage('Password must be at least 6 characters long')
    .matches(/\d/)
    .withMessage('Password must contain at least one number')
    .customSanitizer((value, { req }) => {
      // Hash the password before storing it in the database
      const hashedPassword = hashPassword(value);
      req.body.password = hashedPassword;
      return hashedPassword;
    }),
  (req, res) => {
    // Check for validation errors
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(422).json({ errors: errors.array() });
    }

    // Sanitize input data
    sanitizeBody('username').escape();
    sanitizeBody('email').normalizeEmail();

    // Registration logic here
    const username = req.body.username;
    const email = req.body.email;
    const password = req.body.password;
    const message = `Registered user: ${username} (${email}, ${password})`;
    res.send(message);
  });

// Start the server
app.listen(3000, () => {
  console.log('Server running on port 3000');
});