// WHY: the Content Editor runs on system Node without node_modules, so the user
// guide (docs/felhasznaloi-utmutato.md) is rendered by this small dependency-free
// markdown renderer instead of an external library.
// Supported subset: headings (#..####), bold, inline code, links, ul/ol lists,
// fenced code blocks, horizontal rules, paragraphs. HTML is escaped first.

function escapeHtml(value) {
  return String(value)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

function renderInline(text) {
  return escapeHtml(text)
    .replace(/`([^`]+)`/g, '<code>$1</code>')
    .replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>')
    .replace(/\[([^\]]+)\]\(([^)\s]+)\)/g, '<a href="$2" target="_blank" rel="noopener noreferrer">$1</a>');
}

function renderMarkdown(markdown) {
  const lines = String(markdown).split('\n');
  const out = [];
  let listTag = null; // 'ul' | 'ol'
  let inCode = false;

  const closeList = () => {
    if (listTag) {
      out.push(`</${listTag}>`);
      listTag = null;
    }
  };

  for (const raw of lines) {
    const line = raw.trimEnd();

    if (line.trim().startsWith('```')) {
      closeList();
      out.push(inCode ? '</code></pre>' : '<pre><code>');
      inCode = !inCode;
      continue;
    }
    if (inCode) {
      out.push(escapeHtml(raw));
      continue;
    }
    if (!line.trim()) {
      closeList();
      continue;
    }

    const heading = line.match(/^(#{1,4})\s+(.*)$/);
    if (heading) {
      closeList();
      const level = heading[1].length;
      out.push(`<h${level}>${renderInline(heading[2])}</h${level}>`);
      continue;
    }
    if (/^(-{3,}|\*{3,})$/.test(line.trim())) {
      closeList();
      out.push('<hr>');
      continue;
    }
    const unordered = line.match(/^\s*[-*]\s+(.*)$/);
    if (unordered) {
      if (listTag !== 'ul') {
        closeList();
        out.push('<ul>');
        listTag = 'ul';
      }
      out.push(`<li>${renderInline(unordered[1])}</li>`);
      continue;
    }
    const ordered = line.match(/^\s*\d+\.\s+(.*)$/);
    if (ordered) {
      if (listTag !== 'ol') {
        closeList();
        out.push('<ol>');
        listTag = 'ol';
      }
      out.push(`<li>${renderInline(ordered[1])}</li>`);
      continue;
    }

    closeList();
    out.push(`<p>${renderInline(line)}</p>`);
  }

  closeList();
  if (inCode) out.push('</code></pre>');
  return out.join('\n');
}

module.exports = { renderMarkdown, renderInline, escapeHtml };