class UserCommentSystem {
    constructor() {
        this.container = document.getElementById('user-comments-container');
        this.username = this.container ? this.container.dataset.user : null;
        this.page = 1;
        this.loading = false;
        this.finished = false;
        this.customEmojis = UserCommentSystem.emojiCache || {};

        if (this.username) {
            this.init();
        }
    }

    async init() {
        this.loadEmojis();
        this.loadMore();
        this.bindEvents();
    }

    async loadEmojis() {
        if (UserCommentSystem.emojiCache) {
            this.customEmojis = UserCommentSystem.emojiCache;
            return;
        }
        try {
            const res = await fetch('/api/v2/emojis');
            const data = await res.json();
            if (data.success) {
                this.customEmojis = {};
                data.emojis.forEach(e => {
                    this.customEmojis[e.name] = e.url;
                });
                UserCommentSystem.emojiCache = this.customEmojis;
            }
        } catch (e) {
            console.error("Failed to load emojis", e);
        }
    }

    bindEvents() {
        window.addEventListener('scroll', () => {
            if (this.loading || this.finished) return;
            if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight - 500) {
                this.loadMore();
            }
        });
    }

    async loadMore() {
        if (this.loading || this.finished) return;
        this.loading = true;

        const loader = document.createElement('div');
        loader.className = 'loader-placeholder';
        loader.innerText = 'Loading...';
        loader.style.textAlign = 'center';
        loader.style.padding = '10px';
        this.container.appendChild(loader);

        try {
            const res = await fetch('/user/' + encodeURIComponent(this.username) + '/comments?page=' + this.page + '&json=true');
            const json = await res.json();

            loader.remove();

            if (json.success && json.comments.length > 0) {
                json.comments.forEach(c => {
                    console.log('Raw Comment Content (ID ' + c.id + '):', c.content);
                    const html = this.renderComment(c);
                    this.container.insertAdjacentHTML('beforeend', html);
                });
                this.page++;
            } else {
                this.finished = true;
                if (this.page === 1 && (!json.comments || json.comments.length === 0)) {
                    this.container.innerHTML = '<div style="text-align:center;padding:20px;color:#888;">No comments found.</div>';
                }
            }
        } catch (e) {
            console.error(e);
            loader.remove();
        } finally {
            this.loading = false;
        }
    }

    renderEmoji(match, name) {
        if (this.customEmojis && this.customEmojis[name]) {
            return `<img src="${this.customEmojis[name]}" style="height:60px;vertical-align:middle;" alt="${name}">`;
        }
        return match;
    }

    renderCommentContent(content) {
        if (typeof marked === 'undefined') {
            console.error('UserCommentSystem: marked.js is undefined!');
            return this.escapeHtml(content).replace(/:([a-z0-9_]+):/g, (m, n) => this.renderEmoji(m, n));
        }

        try {
            // 1. Pre-process server-escaped content

            // Fix Greentext: Server sends &gt;lool -> convert to > lool for marked
            let safe = content.replace(/^&gt;/gm, '> ');
            // Also handle raw > just in case
            safe = safe.replace(/^>(?=[^ ])/gm, '> ');

            // Fix Images: Server sends <img src="..." ...> -> convert to markdown ![]() or :emoji:
            // This avoids them being escaped by our HTML escaping later
            safe = safe.replace(/<img\s+[^>]*src="([^"]+)"[^>]*>/g, (match, src) => {
                let altMatch = match.match(/alt="([^"]*)"/);
                let alt = altMatch ? altMatch[1] : '';

                // Check if it's a known emoji (convert back to :code: for consistent rendering)
                // We check if the name exists in our map. Validating src is good but name check is usually enough here.
                if (alt && this.customEmojis && this.customEmojis[alt]) {
                    return `:${alt}:`;
                }

                return `![${alt}](${src})`;
            });

            // 2. Escape HTML (standard safety)
            safe = safe
                .replace(/&/g, "&amp;")
                .replace(/</g, "&lt;")
                .replace(/"/g, "&quot;");

            const renderer = new marked.Renderer();
            renderer.blockquote = function (quote) {
                let text = (typeof quote === 'string') ? quote : (quote.text || '');
                let cleanQuote = text.replace(/<p>|<\/p>|\n/g, '');
                return `<span class="greentext">&gt; ${cleanQuote}</span><br>`;
            };

            // 3. Parse Markdown
            let md = marked.parse(safe, {
                breaks: true,
                renderer: renderer
            });

            return md.replace(/:([a-z0-9_]+):/g, (m, n) => this.renderEmoji(m, n));
        } catch (e) {
            console.error('UserCommentSystem Markdown Render Error:', e);
            return this.escapeHtml(content);
        }
    }

    renderComment(c) {
        const date = new Date(c.created_at).toLocaleString();
        const content = this.renderCommentContent(c.content);

        // Replicating the structure of comments.js but adapting for the list view
        // We add a header indicating which item this comment belongs to

        return `
        <div class="comment" id="c${c.id}">
            <div class="comment-avatar">
               <a href="/${c.item_id}">
                   <img src="/t/${c.item_id}.webp" alt="Item Thumbnail">
               </a>
            </div>
            <div class="comment-body">
                <div class="comment-meta">
                    <span class="comment-author">${this.username}</span>
                    <span class="comment-time">${date}</span>
                    <a href="/${c.item_id}#c${c.id}" class="comment-permalink">#${c.id}</a>
                    <span class="comment-item-ref">on <a href="/${c.item_id}">Item #${c.item_id}</a></span>
                </div>
                <div class="comment-content">${content}</div>
            </div>
        </div>
        `;
    }

    escapeHtml(unsafe) {
        return unsafe
            .replace(/&/g, "&amp;")
            .replace(/</g, "&lt;")
            .replace(/"/g, "&quot;")
            .replace(/>/g, "&gt;");
    }
}

window.addEventListener('DOMContentLoaded', () => {
    new UserCommentSystem();
});