middleware.js

const Listing = require("./models/listing");
const Review = require("./models/review");
const {listingSchema, reviewSchema} = require("./schema.js");
const ExpressError = require("./utils/ExpressError.js");

module.exports.isLoggedIn = (req, res, next) => {
    if(!req.isAuthenticated()) {
        req.session.redirectUrl = req.originalUrl;
        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) => {
    try {
        let {id} = req.params;
    let listing = await Listing.findById(id);
    if(!listing.owner._id.equals(res.locals.currUser._id)) {
        req.flash("error", "you are not the owner of this listing");
        return res.redirect(`/listings/${id}`);
    }
    next();
    } catch (error) {
        const errorMessage = "Page not exists anymore";
        const err = new ExpressError(400, errorMessage);
        next(err);
    }
}

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(400, errMsg);
    } 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(400, errMsg);
    } else {
        next();
    }
}

module.exports.isReviewAuthor = async (req, res, next) => {
    let {id, reviewId} = req.params;
    let review = await Review.findById(reviewId);
    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();
}