import { hashSync, compareSync } from 'bcryptjs';
import { v4 as uuidv4 } from 'uuid';

// In-memory store for demo purposes
let users = [];

export default function handler(req, res) {
  if (req.method !== 'POST') {
    return res.status(405).json({ message: 'Method not allowed' });
  }

  const { username, password } = req.body;

  if (!username || !password) {
    return res.status(400).json({ message: 'Username and password required' });
  }

  // Check if user exists
  const existing = users.find(u => u.username === username);
  if (existing) {
    return res.status(400).json({ message: 'User already exists' });
  }

  const id = uuidv4();
  const hashedPassword = hashSync(password, 10);
  users.push({ id, username, password: hashedPassword });

  // Return a fake JWT token (just a string)
  const token = `${id}:${Date.now()}`;

  res.status(201).json({ token, user: { id, username } });
}