const jwt = require('jsonwebtoken');
const User = require('../models/User');
const { validationResult } = require('express-validator');

// Helper function to generate JWT
const generateToken = (id) => {
  return jwt.sign({ id }, process.env.JWT_SECRET, {
    expiresIn: process.env.JWT_EXPIRATION || '24h'
  });
};

// @desc    Login user
// @route   POST /api/auth/login
// @access  Public
exports.login = async (req, res, next) => {
  try {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ 
        success: false, 
        errors: errors.array() 
      });
    }

    const { email, password } = req.body;

    // Check if user exists
    const user = await User.findOne({ email }).select('+password');
    
    if (!user) {
      return res.status(401).json({
        success: false,
        message: 'Invalid credentials'
      });
    }

    // Check if password matches
    const isMatch = await user.comparePassword(password);
    
    if (!isMatch) {
      return res.status(401).json({
        success: false,
        message: 'Invalid credentials'
      });
    }

    // Generate token
    const token = generateToken(user._id);

    // Remove password from response
    const userResponse = {
      _id: user._id,
      email: user.email,
      role: user.role,
      companyId: user.companyId
    };

    res.status(200).json({
      success: true,
      token,
      user: userResponse
    });
  } catch (error) {
    next(error);
  }
};

// @desc    Get current logged in user
// @route   GET /api/auth/me
// @access  Private
exports.getMe = async (req, res, next) => {
  try {
    const user = await User.findById(req.user.id).select('-password');
    
    res.status(200).json({
      success: true,
      data: user
    });
  } catch (error) {
    next(error);
  }
};