class Article {
    constructor(title, creator) {
        this.title = title;
        this.creator = creator;
        this._comments = [];
        this._likes = [];
        this.id = 1;
        this.first = '';
    }

    get likes() {
        if (this._likes.length === 0) {
            return `${this.title} has 0 likes`;
        }
        if (this._likes.length === 1) {
            return `${this._likes[0]} likes this article!`;
        }
        return `${this.first} and ${this._likes.length - 1} others like this article!`;
    }
    like(username) {

        if (this._likes.includes(username)) {
            throw new Error('You can\'t like the same article twice!');
        }
        if (this.creator === username) {
            throw new Error('You can\'t like your own articles!');
        }
        if (this._likes.length === 0) {
            this.first = username;
        }
        this._likes.push(username);
        return `${username} liked ${this.title}!`;
    }
    dislike(username) {
        if (!this._likes.includes(username)) {
            throw new Error('You can\'t dislike this article!');
        }
        let index = this._likes.findIndex(x => x === username);
        this._likes.splice(index, 1);
        return `${username} disliked ${this.title}`;
    }
    comment(username, content, id) {
        let commentExists = this._comments.find(x => x.id === id);
        if (!commentExists) {
            let obj = {
                id: this.id++,
                username: username,
                content: content,
                replies: []
            }
            this._comments.push(obj);
            return `${username} commented on ${this.title}`;
        }
        let replyObj = {
            id: `${id}.${commentExists.replies.length + 1}`,
            username: username,
            content: content
        }
        commentExists.replies.push(replyObj);
        return 'You replied successfully';
    }
    toString(sortingType) {
        if (sortingType === 'asc') {
            this._comments = this._comments.sort((a, b) => Number(a.id) - Number(b.id));
        }
        if (sortingType === 'desc') {
            this._comments = this._comments.sort((a, b) => Number(b.id) - Number(a.id));
        }
        if (sortingType === 'username') {
            this._comments = this._comments.sort((a, b) => a.username.localeCompare(b.username));
        }
        let result = '';
        result += `Title: ${this.title}\n`;
        result += `Creator: ${this.creator}\n`;
        result += `Likes: ${this._likes.length}\n`;
        result += `Comments:\n`;

        this._comments.forEach(x => {
            result += `-- ${x.id}. ${x.username}: ${x.content}\n`;
            let repliesComment = x.replies;
            if (sortingType === 'asc') {
                repliesComment = repliesComment.sort((a, b) => Number(a.id) - Number(b.id));
            }
            if (sortingType === 'desc') {
                repliesComment = repliesComment.sort((a, b) => Number(b.id) - Number(a.id));
            }
            if (sortingType === 'username') {
                repliesComment = repliesComment.sort((a, b) => a.username.localeCompare(b.username));
            }
            repliesComment.forEach(m => {
                result += `--- ${m.id}. ${m.username}: ${m.content}\n`;
            })
        })
        return result.trim();
    }
}