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

/**
 * Strict authentication middleware. Rejects requests without a valid JWT.
 */
const protect = async (req, res, next) => {
    let token;
    if (
        (req.headers.authorization && req.headers.authorization.startsWith('Bearer')) ||
        req.query.token
    ) {
        try {
            token = req.headers.authorization 
                ? req.headers.authorization.split(' ')[1] 
                : req.query.token;
            const decoded = jwt.verify(token, process.env.JWT_SECRET);
            req.user = await User.findById(decoded.id).select('-password');
            if (!req.user) {
                return res.status(401).json({ message: 'User not found' });
            }
            return next();
        } catch (error) {
            return res.status(401).json({ message: 'Not authorized, token failed' });
        }
    }
    
    return res.status(401).json({ message: 'Not authorized, no token provided' });
};

/**
 * Optional authentication middleware. Populates req.user if a valid token is present,
 * but allows the request to proceed as a guest if no token is found.
 */
const optionalAuth = async (req, res, next) => {
    if (
        (req.headers.authorization && req.headers.authorization.startsWith('Bearer')) ||
        req.query.token
    ) {
        try {
            const token = req.headers.authorization 
                ? req.headers.authorization.split(' ')[1] 
                : req.query.token;
            const decoded = jwt.verify(token, process.env.JWT_SECRET);
            req.user = await User.findById(decoded.id).select('-password');
        } catch (error) {
            // Ignore error and continue as guest
        }
    }
    next();
};

module.exports = {
    protect,
    optionalAuth
};
