artGallery

class ArtGallery{
    constructor(creator){
        this.creator = creator;
        this.possibleArticles = { "picture":200,"photo":50,"item":250 };
        this.listOfArticles = [];
        this.guests = [];
    }

    addArticle(articleModel, articleName, quantity){
       let model = articleModel.toLowerCase();
        if(model != 'picture' && model != 'photo' && model != 'item'){
            throw new Error("This article model is not included in this gallery!");
        }

        let article = this.listOfArticles.find(x=>x.articleName == articleName && x.articleModel == model);
        if(article != undefined){
            article.quantity += quantity;
            return;
        }
       articleModel = articleModel.toLowerCase();
        this.listOfArticles.push({articleModel, articleName, quantity});

        return  `Successfully added article ${articleName} with a new quantity- ${quantity}.`;


    }

    inviteGuest ( guestName, personality){
        let guest = this.guests.find(x=>x.guestName == guestName);
        if(guest != undefined){
            throw new Error(`${guestName} has already been invited.`);
        }
        let points = 0;
        if(personality == 'Vip'){
            points = 500;
        } else if(personality == 'Middle'){
            points = 250;
        } else {
            points = 50;
        }

        this.guests.push({guestName, points, purchaseArticle: 0});

        return `You have successfully invited ${guestName}!`;
    }

    buyArticle ( articleModel, articleName, guestName){

        let artModel = this.listOfArticles.find(x=>x.articleModel == articleModel  && x.articleName == articleName);
        if(artModel == undefined){
            throw new Error("This article is not found.")
        }

        if(artModel.quantity == 0){
            return `The ${articleName} is not available.`;
        }
        let guest = this.guests.find(x=>x.guestName == guestName);
        if(guest == undefined){
            return `This guest is not invited.`;
        }

        if(guest.points >= this.possibleArticles[articleModel]){
            guest.points -= this.possibleArticles[articleModel];
            artModel.quantity -= 1;
            guest.purchaseArticle += 1;
        } else {
            return `You need to more points to purchase the article.`;
        }

        return `${guestName} successfully purchased the article worth ${this.possibleArticles[articleModel]} points.`;
    }

    showGalleryInfo (criteria){
        let result = [];
        if(criteria == 'guest'){
            result.push("Guests information:");
            this.guests.forEach(x=> result.push(`${x.guestName} - ${x.purchaseArticle}`));
        } else if(criteria == 'article'){
            result.push("Articles information:");
            this.listOfArticles.forEach(x=>result.push(`${x.articleModel} - ${x.articleName} - ${x.quantity}`));
        }

        return result.join('\n');
    }
}