jellyfin/MediaBrowser.Providers/Books/AudioBookMetadataService.cs

using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.IO;
using MediaBrowser.Providers.Manager;
using Microsoft.Extensions.Logging;

namespace MediaBrowser.Providers.Books
{
    public class AudioBookMetadataService : MetadataService<AudioBook, SongInfo>
    {
        public AudioBookMetadataService(
            IServerConfigurationManager serverConfigurationManager,
            ILogger<AudioBookMetadataService> logger,
            IProviderManager providerManager,
            IFileSystem fileSystem,
            ILibraryManager libraryManager)
            : base(serverConfigurationManager, logger, providerManager, fileSystem, libraryManager)
        {
        }

        /// <inheritdoc />
        protected override void MergeData(
            MetadataResult<AudioBook> source,
            MetadataResult<AudioBook> target,
            MetadataField[] lockedFields,
            bool replaceData,
            bool mergeMetadataSettings)
        {
            ProviderUtils.MergeBaseItemData(source, target, lockedFields, replaceData, mergeMetadataSettings);

            var sourceItem = source.Item;
            var targetItem = target.Item;

            if (replaceData || targetItem.Artists.Count == 0)
            {
                targetItem.Artists = sourceItem.Artists;
            }

            if (replaceData || string.IsNullOrEmpty(targetItem.Album))
            {
                targetItem.Album = sourceItem.Album;
            }
        }
    }
}