middleware.js

const Campground = require('./models/campground');
const Review = require('./models/review');

module.exports.isLoggedIn = (req, res, next) => {
    if(!req.isAuthenticated()){
        req.session.returnTo = req.originalUrl;
        req.flash('error', "You must be signed in first!");
        return res.redirect('/login');
    }
    next();
}

module.exports.isReviewAuthor = async (req, res, next) => {
    const {id, reviewId} = req.params;
    const review = await Review.findById(reviewId);
    if(!review.author.equals(req.user._id)){
        req.flash('error', 'You do not have permission to do that');
        return res.redirect(`/campgrounds/${id}`);
    }
    next();
}

module.exports.isAuthor = async (req, res, next) => {
    const {id} = req.params;
    const campground = await Campground.findById(id);
    if(!campground.author.equals(req.user._id)){
        req.flash('error', 'You do not have permission to do that');
        return res.redirect(`/campgrounds/${id}`);
    }
    next();
}