/**
 * Markdown & Branded HTML Formatting Utilities for PostFundManagement (PFM)
 */

export function isHtmlContent(content: string): boolean {
  if (!content) return false;
  const trimmed = content.trim();
  return (
    trimmed.startsWith('<!DOCTYPE') ||
    trimmed.startsWith('<html') ||
    trimmed.startsWith('<div') ||
    trimmed.startsWith('<table') ||
    trimmed.startsWith('<p') ||
    trimmed.startsWith('<h') ||
    trimmed.startsWith('<ul') ||
    trimmed.startsWith('<ol') ||
    trimmed.startsWith('<blockquote') ||
    (trimmed.includes('</') && trimmed.includes('>')) ||
    /<(strong|b|em|i|u|h[1-6]|ul|ol|li|table|blockquote|div|p|img|hr|br)\b/i.test(trimmed)
  );
}

export function stripMarkdown(text: string): string {
  if (!text) return '';
  return text
    .replace(/<[^>]*>/g, ' ')
    .replace(/!\[.*?\]\(.*?\)/g, '')
    .replace(/\[(.*?)\]\(.*?\)/g, '$1')
    .replace(/#{1,6}\s+/g, '')
    .replace(/(\*\*|__)(.*?)\1/g, '$2')
    .replace(/(\*|_)(.*?)\1/g, '$2')
    .replace(/~~(.*?)~~/g, '$1')
    .replace(/`{1,3}.*?`{1,3}/gs, '')
    .replace(/^>\s+/gm, '')
    .replace(/^[-*+]\s+/gm, '')
    .replace(/^\d+\.\s+/gm, '')
    .replace(/\|/g, ' ')
    .replace(/\s+/g, ' ')
    .trim();
}

export function parseMarkdownToHtml(markdown: string): string {
  if (!markdown) return '';

  let html = markdown
    .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '')
    .replace(/\r\n/g, '\n');

  html = html.replace(/```([a-zA-Z0-9_-]*)\n([\s\S]*?)```/g, (_match, _lang, code) => {
    const escaped = code
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;');
    return `<pre style="background:#0b1120;border:1px solid #1e293b;border-radius:12px;padding:14px;overflow-x:auto;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;font-size:12px;color:#e2e8f0;margin:12px 0;"><code>${escaped}</code></pre>`;
  });

  html = html.replace(/`([^`]+)`/g, (_match, code) => {
    const escaped = code
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;');
    return `<code style="background:#1e293b;color:#34d399;padding:2px 6px;border-radius:6px;font-family:monospace;font-size:12px;">${escaped}</code>`;
  });

  html = html.replace(/^#### (.*?)$/gm, '<h4 style="font-size:14px;font-weight:700;color:#f8fafc;margin:12px 0 6px 0;">$1</h4>');
  html = html.replace(/^### (.*?)$/gm, '<h3 style="font-size:16px;font-weight:700;color:#f8fafc;margin:14px 0 8px 0;">$1</h3>');
  html = html.replace(/^## (.*?)$/gm, '<h2 style="font-size:18px;font-weight:800;color:#ffffff;margin:16px 0 8px 0;border-bottom:1px solid #1e293b;padding-bottom:6px;">$1</h2>');
  html = html.replace(/^# (.*?)$/gm, '<h1 style="font-size:22px;font-weight:800;color:#ffffff;margin:18px 0 10px 0;border-bottom:1px solid #334155;padding-bottom:8px;">$1</h1>');

  html = html.replace(/\*\*\*(.*?)\*\*\*/g, '<strong><em>$1</em></strong>');
  html = html.replace(/\*\*(.*?)\*\*/g, '<strong style="color:#ffffff;">$1</strong>');
  html = html.replace(/__(.*?)__/g, '<strong style="color:#ffffff;">$1</strong>');
  html = html.replace(/\*(.*?)\*/g, '<em style="color:#cbd5e1;">$1</em>');
  html = html.replace(/\[(.*?)\]\((.*?)\)/g, '<a href="$2" target="_blank" rel="noopener noreferrer" style="color:#34d399;text-decoration:underline;">$1</a>');
  html = html.replace(/^[-*+]\s+(.*?)$/gm, '<li style="margin-left:20px;list-style-type:disc;color:#cbd5e1;padding:2px 0;">$1</li>');
  html = html.replace(/^\d+\.\s+(.*?)$/gm, '<li style="margin-left:20px;list-style-type:decimal;color:#cbd5e1;padding:2px 0;">$1</li>');

  const paragraphs = html.split(/\n{2,}/);
  html = paragraphs
    .map((p) => {
      const trimmed = p.trim();
      if (!trimmed) return '';
      if (
        trimmed.startsWith('<h') ||
        trimmed.startsWith('<div') ||
        trimmed.startsWith('<table') ||
        trimmed.startsWith('<pre') ||
        trimmed.startsWith('<blockquote') ||
        trimmed.startsWith('<hr') ||
        trimmed.startsWith('<li')
      ) {
        return trimmed;
      }
      return `<p style="margin:8px 0;line-height:1.6;color:#cbd5e1;">${trimmed.replace(/\n/g, '<br />')}</p>`;
    })
    .join('\n');

  return html;
}