middleware.js

const Listing = require('./models/listing');
const Review = require('./models/review'); // Don't forget this
const ExpressError = require('./utils/expressError.js');
const { listingSchema,reviewSchema} = require('./schema.js');

module.exports.isLoggedIn = (req,res,next)=>{
    if(!req.isAuthenticated()){
        req.session.redirectUrl=req.originalUrl;//(add new listing)path-->login-->redirect to same previous path
        req.flash("error","You must be logged in to create listing.");
        return res.redirect('/login');
    }next();
}

module.exports.saveRedirectUrl=(req,res,next)=>{
    if(req.session.redirectUrl){
        res.locals.redirectUrl = req.session.redirectUrl;
    }
    next();
};

module.exports.isOwner=async (req,res,next)=>{
    let { id } = req.params;
    let listing  = await Listing.findById(id);
    if(!listing.owner.equals(res.locals.currUser._id)){
        req.flash("error","You are not the owner of this listing.");
        return res.redirect(`/listings/${id}`);
    }
    next();
}

module.exports.validateListing = (req, res, next) => {
    let {error}=listingSchema.validate(req.body);
    if(error) {
        let errMsg = error.details.map(el => el.message).join(', ');
        throw new ExpressError(errMsg, 400);
    }else{
        next();
    }
};

module.exports.validateReview = (req, res, next) => {
    let {error}=reviewSchema.validate(req.body);
    if(error) {
        let errMsg = error.details.map(el => el.message).join(', ');
        throw new ExpressError(errMsg, 400);
    }else{
        next();
    }
};

module.exports.isReviewAuthor=async (req,res,next)=>{
    let { id,reviewId } = req.params;
    let review  = await Review.findById(reviewId);
    if (!review) {
        req.flash("error", "Review not found.");
        return res.redirect(`/listings/${id}`);
    }
    if(!review.author.equals(res.locals.currUser._id)){
        req.flash("error","You are not the author of this review.");
        return res.redirect(`/listings/${id}`);
    }
    next();
}