import jwt from 'jsonwebtoken';

const ROLE_HIERARCHY = {
  'user': 1,
  'moderator': 2,
  'superadmin': 3
};

export function authenticateToken(req, res, next) {
  const authHeader = req.headers['authorization'];
  const token = authHeader && authHeader.split(' ')[1];
  
  if (!token) {
    return res.status(401).json({ error: 'Token required' });
  }
  
  jwt.verify(token, process.env.JWT_SECRET, (err, user) => {
    if (err) {
      return res.status(403).json({ error: 'Invalid token' });
    }
    req.user = user;
    next();
  });
}

// Optional authentication - doesn't fail if no token
export function optionalAuth(req, res, next) {
  const authHeader = req.headers['authorization'];
  const token = authHeader && authHeader.split(' ')[1];
  
  if (!token) {
    req.user = null;
    return next();
  }
  
  jwt.verify(token, process.env.JWT_SECRET, (err, user) => {
    if (err) {
      req.user = null;
    } else {
      req.user = user;
    }
    next();
  });
}

export function requireRole(minRole) {
  return (req, res, next) => {
    const userRole = req.user?.role || 'user';
    const userLevel = ROLE_HIERARCHY[userRole] || 0;
    const requiredLevel = ROLE_HIERARCHY[minRole] || 0;
    
    if (userLevel < requiredLevel) {
      return res.status(403).json({ error: 'Insufficient permissions' });
    }
    next();
  };
}