import jwt from 'jsonwebtoken';

const JWT_SECRET = process.env.JWT_SECRET || 'dev-secret-change-in-production';
const JWT_EXPIRY = '24h';

export function signToken(username) {
  return jwt.sign({ username }, JWT_SECRET, { expiresIn: JWT_EXPIRY });
}

export function verifyToken(token) {
  return jwt.verify(token, JWT_SECRET);
}

export function requireAuth(req, res, next) {
  const header = req.headers.authorization;
  if (!header?.startsWith('Bearer ')) {
    return res.status(401).json({ error: 'Authentication required', code: 'UNAUTHORIZED' });
  }

  try {
    req.user = verifyToken(header.slice(7));
    next();
  } catch {
    return res.status(401).json({ error: 'Invalid or expired token', code: 'UNAUTHORIZED' });
  }
}