authController.js

const User = require('../models/User');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');

// Sign Up
exports.signup = async (req, res) => {
    const { username, email, password, birthday } = req.body;

    try {
        // Check if the user already exists
        const existingUser = await User.findOne({ email });
        if (existingUser) return res.status(400).json({ error: 'User already exists' });

        // Hash the password
        const hashedPassword = await bcrypt.hash(password, 12);

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

        res.status(201).json({ message: 'User created successfully' });
    } catch (err) {
        res.status(500).json({ error: 'Server error' });
    }
};

// Sign In
exports.signin = async (req, res) => {
    const { username, password } = req.body;

    try {
        // Check if the user exists
        const user = await User.findOne({ username });
        if (!user) return res.status(400).json({ error: 'Invalid credentials' });

        // Validate password
        const isMatch = await bcrypt.compare(password, user.password);
        if (!isMatch) return res.status(400).json({ error: 'Invalid credentials' });

        // Generate JWT token
        const token = jwt.sign({ userId: user._id }, process.env.JWT_SECRET, { expiresIn: '1h' });

        res.json({ token });
    } catch (err) {
        res.status(500).json({ error: 'Server error' });
    }
};