// Blog Post Viewer

(function() {
    'use strict';
    
    function getPostId() {
        const params = new URLSearchParams(window.location.search);
        return params.get('id');
    }
    
    async function fetchPost(postId) {
        try {
            const response = await fetch(`/api/blog/post/${postId}`, {
                method: 'GET',
                headers: {
                    'Accept': 'application/json'
                }
            });
            
            if (!response.ok) {
                console.warn(`Post API request failed: ${response.status}`);
                return null;
            }

            const post = await response.json();
            console.log(`✓ Fetched post: ${post.name}`);
            return post;
            
        } catch (error) {
            console.error('Post API fetch error:', error.message);
            return null;
        }
    }
    
    /**
     * Format date to readable string
     */
    function formatDate(dateString) {
        const date = new Date(dateString);
        const options = { year: 'numeric', month: 'long', day: 'numeric' };
        return date.toLocaleDateString('en-US', options);
    }
    
    function parseMarkdown(markdown) {
        if (!markdown) return '<p>No content available.</p>';
        
        if (typeof marked !== 'undefined' && typeof hljs !== 'undefined') {
            marked.setOptions({
                highlight: function(code, lang) {
                    if (lang && hljs.getLanguage(lang)) {
                        return hljs.highlight(code, { language: lang }).value;
                    }
                    return hljs.highlightAuto(code).value;
                },
                breaks: true,
                gfm: true
            });
            return marked.parse(markdown);
        }
        
        let html = markdown
            .replace(/```(\w+)?\n([\s\S]*?)```/g, '<pre><code class="language-$1">$2</code></pre>')
            .replace(/^#### (.*$)/gim, '<h4>$1</h4>')
            .replace(/^### (.*$)/gim, '<h3>$1</h3>')
            .replace(/^## (.*$)/gim, '<h2>$1</h2>')
            .replace(/^# (.*$)/gim, '<h1>$1</h1>')
            .replace(/^---$/gm, '<hr>')
            .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
            .replace(/\*(.+?)\*/g, '<em>$1</em>')
            .replace(/`([^`]+)`/g, '<code>$1</code>')
            .replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2" target="_blank" rel="noopener noreferrer">$1</a>')
            .replace(/!\[([^\]]*)\]\(([^)]+)\)/g, '<img src="$2" alt="$1" style="max-width: 100%; height: auto;">')
            .replace(/^\* (.+)$/gm, '<li>$1</li>')
            .replace(/(<li>.*<\/li>)/s, '<ul>$1</ul>')
            .replace(/^\d+\. (.+)$/gm, '<li>$1</li>')
            .replace(/^> (.+)$/gm, '<blockquote>$1</blockquote>')
            .split('\n\n')
            .map(para => {
                para = para.trim();
                if (para.match(/^<(h[1-6]|ul|ol|pre|blockquote|hr)/)) {
                    return para;
                }
                return para ? `<p>${para}</p>` : '';
            })
            .join('\n');
        
        return html;
    }
    
    /**
     * Render post to DOM
     */
    function renderPost(post) {
        const loading = document.getElementById('post-loading');
        const content = document.getElementById('post-content');
        const error = document.getElementById('post-error');
        
        if (!post) {
            loading.style.display = 'none';
            error.style.display = 'block';
            return;
        }
        
        loading.style.display = 'none';
        content.style.display = 'block';
        
        // Update page title
        document.getElementById('page-title').textContent = `${post.name} - pyserve`;
        document.getElementById('breadcrumb-title').textContent = post.name;
        
        // Update meta
        const date = formatDate(post.published_at || post.created_at);
        document.getElementById('post-date').textContent = date;
        document.getElementById('post-tag').textContent = post.tag_name || 'post';
        
        // Update title
        document.getElementById('post-title').textContent = post.name;
        
        // Parse and render body
        const bodyHtml = parseMarkdown(post.body);
        document.getElementById('post-body').innerHTML = bodyHtml;
        
        // Update author info
        if (post.author) {
            const authorSection = document.getElementById('post-author-full');
            const avatarImg = document.getElementById('author-avatar');
            const authorName = document.getElementById('author-name');
            const authorLogin = document.getElementById('author-login');
            
            if (avatarImg) {
                avatarImg.src = post.author.avatar_url || 'https://via.placeholder.com/80';
                avatarImg.alt = post.author.full_name || post.author.login;
            }
            if (authorName) authorName.textContent = post.author.full_name || post.author.login;
            if (authorLogin) authorLogin.textContent = `@${post.author.login}`;
            
            authorSection.style.display = 'flex';
        }
    }
    
    /**
     * Show error state
     */
    function showError() {
        const loading = document.getElementById('post-loading');
        const error = document.getElementById('post-error');
        
        loading.style.display = 'none';
        error.style.display = 'block';
    }
    
    /**
     * Main initialization
     */
    async function init() {
        const postId = getPostId();
        
        if (!postId) {
            showError();
            return;
        }
        
        const post = await fetchPost(postId);
        
        if (post) {
            renderPost(post);
        } else {
            showError();
        }
    }
    
    // Start when DOM is ready
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }
    
})();