export function extractLatexImages(html: string) {
  const imgRegex =
    /<img[^>]+src="(https:\/\/latex\.codecogs\.com\/gif\.latex\?(=?.*?))"[^>]*>/g;
  let parts = [];
  let latexMatches: string[] = [];
  let lastIndex = 0;

  html.replace(imgRegex, (match, _, latex, index) => {
    parts.push(html.slice(lastIndex, index)); // Add HTML before image
    latexMatches.push(decodeURIComponent(latex)); // Extract and decode LaTeX
    lastIndex = index + match.length;
    return "";
  });

  parts.push(html.slice(lastIndex)); // Add remaining HTML after last image

  return { parts, latexMatches };
}

export function renderLatex(html: string) {
  const { parts, latexMatches } = extractLatexImages(html);
  const outputHtml = parts
    .map((part, i) => {
      if (!latexMatches[i]) {
        return part;
      }
      return `${part}$$${latexMatches[i]}$$`;
    })
    .join("");
  // Remove all "\," from string
  const regex = /\\,/g;
  return outputHtml.replace(regex, " ");
}