const jwt = require('jsonwebtoken');
const { User } = require('../models');

const auth = async (req, res, next) => {
  try {
    const token = req.header('Authorization')?.replace('Bearer ', '');
    
    if (!token) {
      return res.status(401).json({ error: 'Access denied. No token provided.' });
    }

    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    const user = await User.findByPk(decoded.userId);

    if (!user || !user.isActive) {
      return res.status(401).json({ error: 'Invalid token or user inactive.' });
    }

    req.user = user;
    next();
  } catch (error) {
    res.status(401).json({ error: 'Invalid token.' });
  }
};

const requireRole = (roles) => {
  return (req, res, next) => {
    if (!req.user) {
      return res.status(401).json({ error: 'Authentication required.' });
    }

    if (!roles.includes(req.user.role)) {
      return res.status(403).json({ error: 'Insufficient permissions.' });
    }

    next();
  };
};

const requireSuperAdmin = requireRole(['super_admin']);
const requireTrainer = requireRole(['super_admin', 'trainer']);
const requireTrainee = requireRole(['super_admin', 'trainer', 'trainee']);

module.exports = {
  auth,
  requireRole,
  requireSuperAdmin,
  requireTrainer,
  requireTrainee
};