jellyfin-server/MediaBrowser.Providers/Music/Extensions.cs

using System.Linq;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Model.Entities;

namespace MediaBrowser.Providers.Music
{
    public static class Extensions
    {
        public static string GetAlbumArtist(this AlbumInfo info)
        {
            var id = info.SongInfos.SelectMany(i => i.AlbumArtists)
                    .FirstOrDefault(i => !string.IsNullOrEmpty(i));

            if (!string.IsNullOrEmpty(id))
            {
                return id;
            }

            return info.AlbumArtists.FirstOrDefault();
        }

        public static string GetReleaseGroupId(this AlbumInfo info)
        {
            var id = info.GetProviderId(MetadataProviders.MusicBrainzReleaseGroup);

            if (string.IsNullOrEmpty(id))
            {
                return info.SongInfos.Select(i => i.GetProviderId(MetadataProviders.MusicBrainzReleaseGroup))
                    .FirstOrDefault(i => !string.IsNullOrEmpty(i));
            }

            return id;
        }

        public static string GetReleaseId(this AlbumInfo info)
        {
            var id = info.GetProviderId(MetadataProviders.MusicBrainzAlbum);

            if (string.IsNullOrEmpty(id))
            {
                return info.SongInfos.Select(i => i.GetProviderId(MetadataProviders.MusicBrainzAlbum))
                    .FirstOrDefault(i => !string.IsNullOrEmpty(i));
            }

            return id;
        }

        public static string GetMusicBrainzArtistId(this AlbumInfo info)
        {
            info.ProviderIds.TryGetValue(MetadataProviders.MusicBrainzAlbumArtist.ToString(), out var id);

            if (string.IsNullOrEmpty(id))
            {
                info.ArtistProviderIds.TryGetValue(MetadataProviders.MusicBrainzArtist.ToString(), out id);
            }

            if (string.IsNullOrEmpty(id))
            {
                return info.SongInfos.Select(i => i.GetProviderId(MetadataProviders.MusicBrainzAlbumArtist))
                    .FirstOrDefault(i => !string.IsNullOrEmpty(i));
            }

            return id;
        }

        public static string GetMusicBrainzArtistId(this ArtistInfo info)
        {
            info.ProviderIds.TryGetValue(MetadataProviders.MusicBrainzArtist.ToString(), out var id);

            if (string.IsNullOrEmpty(id))
            {
                return info.SongInfos.Select(i => i.GetProviderId(MetadataProviders.MusicBrainzAlbumArtist))
                    .FirstOrDefault(i => !string.IsNullOrEmpty(i));
            }

            return id;
        }
    }
}