String mangaSlugFromUrl(String pageUrl) {
  try {
    final parts = Uri.parse(pageUrl).pathSegments.where((s) => s.isNotEmpty).toList();
    final mi = parts.indexOf('manga');
    if (mi != -1 && mi + 1 < parts.length) {
      return parts[mi + 1];
    }
  } catch (_) {}
  return 'comic';
}

String mangaBaseUrlFromListingUrl(String pageUrl) {
  final u = Uri.parse(pageUrl);
  final parts = u.pathSegments.where((s) => s.isNotEmpty).toList();
  final mi = parts.indexOf('manga');
  if (mi == -1 || mi + 1 >= parts.length) {
    throw StateError(
      'Could not find /manga/{slug}/ in URL; use a manga or chapter link from MangaRead.',
    );
  }
  final slug = parts[mi + 1];
  return Uri(scheme: u.scheme, host: u.host, path: '/manga/$slug/').toString();
}

String listingUrlForSlug(String slug, {String origin = 'https://www.mangaread.org'}) {
  final base = origin.replaceAll(RegExp(r'/+$'), '');
  return '$base/manga/$slug/';
}

String chapterKeyFromUrl(String chapterUrl) {
  try {
    final segs = Uri.parse(chapterUrl).pathSegments.where((s) => s.isNotEmpty).toList();
    return segs.isEmpty ? 'chapter' : segs.last;
  } catch (_) {
    return 'chapter';
  }
}

String? chapterNumberFromTitle(String title) {
  final m = RegExp(r'(?:Chapter|Ch\.?)\s*([\d.]+)', caseSensitive: false)
      .firstMatch(title.trim().replaceAll(RegExp(r'\s+'), ' '));
  return m?.group(1);
}

String absoluteUrl(String href, String baseHref) {
  return Uri.parse(baseHref).resolve(href.trim()).toString();
}