class ChannelNameFormatter {
  static final Map<String, String> _cache = <String, String>{};
  static const Set<String> _qualityTokens = <String>{
    'SD',
    'HD',
    'FHD',
    'UHD',
    '4K',
    '8K',
    'HDR',
    'HEVC',
    'H264',
    'H265',
    'FULLHD',
  };

  static String forDisplay(String rawName) {
    if (rawName.isEmpty) return rawName;

    final cached = _cache[rawName];
    if (cached != null) return cached;

    var display = rawName.trim();

    final pipeIndex = display.indexOf('|');
    if (pipeIndex >= 0 && pipeIndex < display.length - 1) {
      display = display.substring(pipeIndex + 1).trim();
    }

    display = display.replaceFirst(RegExp(r'^[\-\–\—:]+'), '').trim();

    if (display.isNotEmpty) {
      final parts = display.split(RegExp(r'\s+')).toList(growable: true);
      while (parts.isNotEmpty && _isQualityToken(parts.last)) {
        parts.removeLast();
      }
      display = parts.join(' ').trim();
    }

    if (display.isEmpty) {
      display = rawName.trim();
    }

    if (_cache.length > 50000) {
      _cache.clear();
    }
    _cache[rawName] = display;
    return display;
  }

  static bool _isQualityToken(String token) {
    final normalized = token.toUpperCase().replaceAll(RegExp(r'[^A-Z0-9]'), '');
    return _qualityTokens.contains(normalized);
  }
}