// ====== Related Posts (Blogger) - same label, 3 items, after 2021, nice links ======
(function () {
  const MIN_DATE = new Date('2022-01-01T00:00:00Z'); // μετά το 2021
  const MAX_RESULTS_FETCH = 50;
  const ITEMS_TO_SHOW = 3;
  const GUARD_ATTR = 'data-crml-related-done';

  // ---- CSS ----
  (function injectCSS(){
    if (document.getElementById('crml-related-style')) return;
    const css = `
      .crml-related{margin:24px 0 8px}
      .crml-related h3{margin:0 0 10px;font-size:1.05rem}
      .crml-related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
      @media (max-width:720px){.crml-related-grid{grid-template-columns:1fr}}
      .crml-related-card{background:#fff8e1;border:1px solid #f0e2b6;border-radius:14px;padding:12px;box-shadow:0 2px 6px rgba(0,0,0,.06);transition:transform .1s ease, box-shadow .1s ease}
      .crml-related-card:hover{transform:translateY(-1px);box-shadow:0 4px 10px rgba(0,0,0,.08)}
      .crml-related-link{display:block;font-weight:600;text-decoration:none;color:#1a3d6b;line-height:1.3}
      .crml-related-meta{margin-top:6px;font-size:.85rem;opacity:.8}
    `;
    const s = document.createElement('style');
    s.id = 'crml-related-style';
    s.textContent = css;
    document.head.appendChild(s);
  })();

  const $ = (sel, root=document) => root.querySelector(sel);

  function getTargetRoot(){
    // Προτιμάμε τον γονέα της βασικής post-body
    const body = document.querySelector('.post-body,[itemprop="articleBody"]');
    if (body && body.parentElement) return body.parentElement;
    // Fallback: το πρώτο βασικό wrapper
    return document.querySelector('.post, article, .post-outer') || document.body;
  }

  function getCurrentPostLink(root){
    const a = $('h1 a, h2 a, .post-title a, [itemprop="headline"] a', root) || $('a[rel="bookmark"]', root);
    return a ? a.href : window.location.href;
  }

  function getOneLabel(root){
    const lbl = $('.post-labels a, .label a, a[rel="tag"]', root) || document.querySelector('.post-labels a, .label a, a[rel="tag"]');
    return lbl ? lbl.textContent.trim() : '';
  }

  function isoDateToDate(s){ const d=new Date(s); return isNaN(d)?null:d; }

  async function fetchByLabel(label){
    const base = `${location.origin}/feeds/posts/summary/-/${encodeURIComponent(label)}`;
    const url = `${base}?alt=json&max-results=${MAX_RESULTS_FETCH}&orderby=published&v=2`;
    const res = await fetch(url, { credentials: 'same-origin' });
    if (!res.ok) throw new Error('Feed HTTP error ' + res.status);
    const data = await res.json();
    return data && data.feed && Array.isArray(data.feed.entry) ? data.feed.entry : [];
  }

  function pickAlternateLink(entry){
    const links = entry.link || [];
    const alt = links.find(l => l.rel === 'alternate');
    return alt ? alt.href : null;
    }

  function renderRelated(root, items, label){
    // Αν έχει ήδη μπει, μην ξαναβάλεις
    if (root.hasAttribute(GUARD_ATTR) || root.querySelector('.crml-related')) return;

    const body = root.querySelector('.post-body,[itemprop="articleBody"]') || root;
    const wrap = document.createElement('div');
    wrap.className = 'crml-related';
    wrap.innerHTML = `
      <h3>Σχετικές αναρτήσεις (${label})</h3>
      <div class="crml-related-grid"></div>
    `;
    const grid = wrap.querySelector('.crml-related-grid');

    items.forEach(it=>{
      const card = document.createElement('div');
      card.className = 'crml-related-card';
      const a = document.createElement('a');
      a.className = 'crml-related-link';
      a.href = it.url;
      a.textContent = it.title;
      const meta = document.createElement('div');
      meta.className = 'crml-related-meta';
      meta.textContent = new Date(it.date).toLocaleDateString();
      card.appendChild(a);
      card.appendChild(meta);
      grid.appendChild(card);
    });

    body.parentElement.insertBefore(wrap, body.nextSibling);
    root.setAttribute(GUARD_ATTR, '1'); // σημαδάκι για να μη ξαναμπεί
  }

  async function buildOnce(){
    const root = getTargetRoot();
    if (!root || root.hasAttribute(GUARD_ATTR)) return;

    const label = getOneLabel(root);
    if (!label) return;

    const currentURL = getCurrentPostLink(root);

    let entries = [];
    try { entries = await fetchByLabel(label); } catch(e){ return; }

    const items = entries.map(e=>({
      title: (e.title && e.title.$t) || '(Χωρίς τίτλο)',
      url: pickAlternateLink(e),
      date: e.published ? e.published.$t : null
    })).filter(x => x.url && x.date);

    const filtered = items.filter(x => {
      const d = isoDateToDate(x.date);
      return d && d >= MIN_DATE; // μετά το 2021
    }).filter(x => x.url !== currentURL) // όχι η τρέχουσα
      .sort((a,b) => new Date(b.date) - new Date(a.date)) // νεότερα πρώτα
      .slice(0, ITEMS_TO_SHOW);

    if (filtered.length) renderRelated(root, filtered, label);
  }

  if (document.readyState === 'loading'){
    document.addEventListener('DOMContentLoaded', buildOnce);
  } else {
    buildOnce();
  }
})();