// blog.js – Loads and renders blog posts with simple "Read more" toggle for long entries

const BLOG_DIR = 'blog/';
const MANIFEST = BLOG_DIR + 'manifest.json';

// ---------- helpers ----------

// crude HTML parser for directory listings (when manifest is missing)
function parseIndexHtmlList(html) {
  const hrefs = [];
  const re = /href="([^"]+)"/g;
  let m;
  while ((m = re.exec(html)) !== null) {
    const name = m[1];
    // accept typical text file extensions (and no extension)
    if (name.match(/\.(txt|md|text)$/i) || !name.includes('.')) {
      if (!name.endsWith('/')) hrefs.push(name);
    }
  }
  return hrefs;
}

// fetch list of blog post filenames (manifest first, fallback to directory listing)
async function loadPostList() {
  try {
    const r = await fetch(MANIFEST, { cache: 'no-cache' });
    if (r.ok) return await r.json();
  } catch (_) { /* ignore */ }

  try {
    const r = await fetch(BLOG_DIR, { cache: 'no-cache' });
    if (r.ok) {
      const html = await r.text();
      return parseIndexHtmlList(html);
    }
  } catch (e) {
    console.warn('Could not read blog directory listing', e);
  }
  return [];
}

// fetch a single post file
async function fetchPost(filename) {
  const res = await fetch(BLOG_DIR + filename, { cache: 'no-cache' });
  if (!res.ok) throw new Error(`Failed to fetch ${filename}`);
  return await res.text();
}

// ---------- rendering ----------

function renderPost(filename, content) {
  const lines = content.split('\n');
  if (lines.length < 3) {
    return null; // malformed
  }
  const dateTime = lines[0].trim();
  const title = lines[1].trim();
  const bodyLines = lines.slice(2);
  const body = bodyLines.join('\n').trim();

  const postDiv = document.createElement('div');
  postDiv.className = 'blog-post';

  // Title
  const titleEl = document.createElement('h3');
  titleEl.className = 'blog-title';
  titleEl.textContent = title;
  postDiv.appendChild(titleEl);

  // Date
  const metaEl = document.createElement('p');
  metaEl.className = 'blog-meta';
  metaEl.textContent = dateTime;
  postDiv.appendChild(metaEl);

  const isLong = body.length > 300;

  // Body container (always created, but hidden for long posts)
  const bodyDiv = document.createElement('div');
  bodyDiv.className = 'blog-body';
  bodyDiv.style.whiteSpace = 'pre-line';
  bodyDiv.textContent = body;

  if (!isLong) {
    // Short post – show body directly
    postDiv.appendChild(bodyDiv);
  } else {
    // Long post – hide body initially, add toggle button
    bodyDiv.style.display = 'none';
    postDiv.appendChild(bodyDiv);

    // Toggle button
    const toggleBtn = document.createElement('button');
    toggleBtn.className = 'blog-toggle';
    toggleBtn.textContent = 'Read more';
    postDiv.appendChild(toggleBtn);

    toggleBtn.addEventListener('click', function() {
      const isHidden = bodyDiv.style.display === 'none';
      bodyDiv.style.display = isHidden ? 'block' : 'none';
      this.textContent = isHidden ? 'Show less' : 'Read more';
    });
  }

  return postDiv;
}

// ---------- main ----------

async function initBlog() {
  const feed = document.querySelector('.blog-feed');
  if (!feed) return;

  feed.textContent = 'Loading blog posts…';

  try {
    const files = await loadPostList();
    if (!files.length) {
      feed.textContent = 'No blog posts found.';
      return;
    }

    files.sort(); // alphabetical -> chronological

    feed.innerHTML = '';

    for (const file of files) {
      try {
        const content = await fetchPost(file);
        const el = renderPost(file, content);
        if (el) feed.appendChild(el);
      } catch (err) {
        console.warn(`Failed to load ${file}:`, err);
        const errDiv = document.createElement('div');
        errDiv.className = 'blog-post';
        errDiv.style.color = '#b91c1c';
        errDiv.textContent = `⚠️ Could not load post: ${file}`;
        feed.appendChild(errDiv);
      }
    }

    if (feed.children.length === 0) {
      feed.textContent = 'No valid blog posts found.';
    }
  } catch (err) {
    console.error('Blog init error:', err);
    feed.textContent = 'Error loading blog posts.';
  }
}

document.addEventListener('DOMContentLoaded', initBlog);