export const MINDSPACE_PAGE_TAG_ATTR = 'data-mindspace-page-tag';
export const MINDSPACE_PAGE_TAG_PLATFORM_BRAND = 'platform-brand';
export const PLATFORM_BRAND_TEXT = 'TKMind · 智趣';
export const PLATFORM_BRAND_STYLE_ID = 'mindspace-platform-brand-style';

const PLATFORM_BRAND_VISIBILITY_STYLE = `<style id="${PLATFORM_BRAND_STYLE_ID}">
[data-mindspace-page-tag="${MINDSPACE_PAGE_TAG_PLATFORM_BRAND}"] {
  display: block !important;
  opacity: 1 !important;
  visibility: visible !important;
  color: #9aa3a0 !important;
  font-size: 12px !important;
  font-weight: 600 !important;
  letter-spacing: 0.08em !important;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
}
</style>`;

const PLATFORM_BRAND_INNER_RE = /(?:TKMind\s*·\s*智趣|contact@tkmind\.(?:ai|cn)|📧[^<]*tkmind)/i;
const SIMPLE_BRAND_ELEMENT_RE =
  /<(p|div|span|small|footer|a)(\s[^>]*)?>([^<]*(?:TKMind\s*·\s*智趣|contact@tkmind\.(?:ai|cn)|📧[^<]*tkmind)[^<]*)<\/\1>/gi;

export function normalizePlatformDomainText(text) {
  return String(text ?? '').replace(/tkmind\.ai/gi, 'tkmind.cn');
}

export function normalizePlatformBrandHtml(html) {
  let next = normalizePlatformDomainText(html);
  next = next.replace(/mailto:([^"'>\s]+@tkmind)\.ai/gi, 'mailto:$1.cn');
  next = next.replace(/https?:\/\/([a-z0-9.-]*\.)?tkmind\.ai/gi, (match) =>
    match.replace(/tkmind\.ai/gi, 'tkmind.cn'),
  );
  next = next.replace(/(?:📧\s*)?contact@tkmind\.cn/gi, PLATFORM_BRAND_TEXT);
  return next;
}

export function ensurePlatformBrandPageTags(html) {
  const normalized = normalizePlatformBrandHtml(html);
  return normalized.replace(SIMPLE_BRAND_ELEMENT_RE, (match, tag, attrs, inner) => {
    const attrStr = attrs ?? '';
    if (attrStr.includes(MINDSPACE_PAGE_TAG_ATTR)) return match;
    if (!PLATFORM_BRAND_INNER_RE.test(inner)) return match;
    const spacer = attrStr ? '' : ' ';
    return `<${tag}${attrStr}${spacer}${MINDSPACE_PAGE_TAG_ATTR}="${MINDSPACE_PAGE_TAG_PLATFORM_BRAND}">${inner}</${tag}>`;
  });
}

export function hasPlatformBrandMarker(html) {
  return new RegExp(
    `${MINDSPACE_PAGE_TAG_ATTR}\\s*=\\s*["']${MINDSPACE_PAGE_TAG_PLATFORM_BRAND}["']`,
    'i',
  ).test(String(html ?? ''));
}

/** Append the platform brand footer when authors omitted data-mindspace-page-tag. */
export function ensurePlatformBrandFooter(html) {
  const normalized = ensurePlatformBrandPageTags(html);
  if (hasPlatformBrandMarker(normalized)) return normalized;
  const footer = `<p ${MINDSPACE_PAGE_TAG_ATTR}="${MINDSPACE_PAGE_TAG_PLATFORM_BRAND}">${PLATFORM_BRAND_TEXT}</p>`;
  if (/<\/body>/i.test(normalized)) {
    return normalized.replace(/<\/body>/i, `${footer}\n</body>`);
  }
  return `${normalized}\n${footer}`;
}

/** Override author CSS that hides the platform brand line (e.g. opacity 0.25). */
export function injectPlatformBrandVisibilityStyle(html) {
  const source = String(html ?? '');
  if (!hasPlatformBrandMarker(source) || source.includes(PLATFORM_BRAND_STYLE_ID)) return source;
  if (/<\/head>/i.test(source)) {
    return source.replace(/<\/head>/i, `${PLATFORM_BRAND_VISIBILITY_STYLE}\n</head>`);
  }
  return `${PLATFORM_BRAND_VISIBILITY_STYLE}${source}`;
}

export function preparePublishedPlatformBrand(html) {
  return injectPlatformBrandVisibilityStyle(ensurePlatformBrandFooter(html));
}

export function prepareHtmlPageBrandMarkers(html) {
  return ensurePlatformBrandPageTags(html);
}