import express from 'express';
import jwt from 'jsonwebtoken';
import User from '../models/User.js';

const router = express.Router();

// Register
router.post('/register', async (req, res) => {
  try {
    const { username, email, password } = req.body;

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

    if (password.length < 6) {
      return res.status(400).json({
        message: 'Password must be at least 6 characters long'
      });
    }

    // Check if user already exists
    const existingUser = await User.findOne({
      $or: [{ email }, { username }]
    });

    if (existingUser) {
      return res.status(400).json({
        message: 'User with this email or username already exists'
      });
    }

    // Create new user
    const user = new User({ username, email, password });
    await user.save();

    // Generate JWT token
    const token = jwt.sign(
      { userId: user._id },
      process.env.JWT_SECRET,
      { expiresIn: '7d' }
    );

    res.status(201).json({
      message: 'User created successfully',
      token,
      user: {
        id: user._id,
        username: user.username,
        email: user.email
      }
    });
  } catch (error) {
    console.error('Registration error:', error);
    res.status(500).json({ message: 'Server error', error: error.message });
  }
});

// Login
router.post('/login', async (req, res) => {
  try {
    const { email, password } = req.body;

    // Find user by email
    const user = await User.findOne({ email });
    if (!user) {
      return res.status(400).json({ message: 'Invalid credentials' });
    }

    // Check password
    const isMatch = await user.comparePassword(password);
    if (!isMatch) {
      return res.status(400).json({ message: 'Invalid credentials' });
    }

    // Generate JWT token
    const token = jwt.sign(
      { userId: user._id },
      process.env.JWT_SECRET,
      { expiresIn: '7d' }
    );

    res.json({
      message: 'Login successful',
      token,
      user: {
        id: user._id,
        username: user.username,
        email: user.email
      }
    });
  } catch (error) {
    res.status(500).json({ message: 'Server error', error: error.message });
  }
});

export default router;