import DOMPurify from 'dompurify';
import { marked } from 'marked';

marked.setOptions({
  gfm: true,
  breaks: true,
});

const markdownCache = new Map();
const inlineCache = new Map();

function sanitizeHtml(html) {
  return DOMPurify.sanitize(html, {
    USE_PROFILES: { html: true },
  });
}

function toSafeString(value) {
  if (typeof value === 'string') {
    return value.trim();
  }
  if (value === null || value === undefined) {
    return '';
  }
  return String(value).trim();
}

function parseMarkdown(source) {
  const parsed = marked.parse(source);
  if (typeof parsed === 'string') {
    return parsed;
  }
  return '';
}

function parseInlineMarkdown(source) {
  const parsed = marked.parseInline(source);
  if (typeof parsed === 'string') {
    return parsed;
  }
  return '';
}

export function renderMarkdown(value) {
  const source = toSafeString(value);
  if (!source) {
    return '';
  }

  if (markdownCache.has(source)) {
    return markdownCache.get(source);
  }

  const html = sanitizeHtml(parseMarkdown(source));
  markdownCache.set(source, html);
  return html;
}

export function renderInlineMarkdown(value) {
  const source = toSafeString(value);
  if (!source) {
    return '';
  }

  if (inlineCache.has(source)) {
    return inlineCache.get(source);
  }

  const html = sanitizeHtml(parseInlineMarkdown(source));
  inlineCache.set(source, html);
  return html;
}