parsePlaylistHeaderMeta function

Implementation

JsonMap parsePlaylistHeaderMeta(JsonMap header) {
  final playlistMeta = <String, dynamic>{
    'views': null,
    'duration': null,
    'trackCount': null,
    'title':
        ((header['title'] as JsonMap?)?['runs'] as List? ?? [])
            .map((run) => (run as JsonMap)['text'])
            .join(),
    'thumbnails': nav(header, THUMBNAILS),
  };

  if (header.containsKey('facepile')) {
    final avatarRenderer = nav(header, [
      'facepile',
      'avatarStackViewModel',
      'rendererContext',
    ]);

    final avatarCommand = nav(avatarRenderer, [
      'commandContext',
      'onTap',
      'innertubeCommand',
    ], nullIfAbsent: true);

    if (nav(avatarCommand, [
          'showEngagementPanelEndpoint',
          'identifier',
          'tag',
        ], nullIfAbsent: true) ==
        'PAplaylist_collaborate') {
      final avatars = List<JsonMap>.from(
        nav(header, ['facepile', 'avatarStackViewModel', 'avatars']) as List,
      );

      playlistMeta['collaborators'] = {
        'text': nav(avatarRenderer, ['accessibilityContext', 'label']),
        'avatars': [
          for (final avatar in avatars)
            (((avatar['avatarViewModel'] as JsonMap)['image']
                    as JsonMap)['sources']
                as List)[0],
        ],
      };
    } else {
      playlistMeta['author'] = {
        'name': nav(header, [
          'facepile',
          'avatarStackViewModel',
          'text',
          'content',
        ]),
        'id': nav(avatarCommand, [
          'browseEndpoint',
          'browseId',
        ], nullIfAbsent: true),
      };
    }
  }

  final secondSubtitleRuns =
      nav(header, ['secondSubtitle', 'runs'], nullIfAbsent: true) as List?;

  if (secondSubtitleRuns != null) {
    final hasViews = secondSubtitleRuns.length > 3 ? 2 : 0;
    playlistMeta['views'] =
        hasViews == 0
            ? null
            : toInt((secondSubtitleRuns[0] as JsonMap)['text'] as String);

    final hasDuration = secondSubtitleRuns.length > 1 ? 2 : 0;
    playlistMeta['duration'] =
        hasDuration == 0
            ? null
            : (secondSubtitleRuns[hasViews + hasDuration] as JsonMap)['text'];

    final songCountText =
        (secondSubtitleRuns[hasViews] as JsonMap)['text'] as String;

    final songCountSearch =
        RegExp(
          r'\d+',
        ).allMatches(songCountText).map((match) => match.group(0)!).toList();

    playlistMeta['trackCount'] =
        songCountSearch.isNotEmpty ? toInt(songCountSearch.join()) : null;
  }

  return playlistMeta;
}