Merge branch 'master' into comparisons

33 files changed, 488 insertions, 383 deletions

diff --git a/MediaBrowser.Controller/Entities/AggregateFolder.cs b/MediaBrowser.Controller/Entities/AggregateFolder.cs
index f1944a7d3..fe1bc62ab 100644
--- a/MediaBrowser.Controller/Entities/AggregateFolder.cs
+++ b/MediaBrowser.Controller/Entities/AggregateFolder.cs
@@ -22,6 +22,8 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class AggregateFolder : Folder
     {
+        private bool _requiresRefresh;
+
         public AggregateFolder()
         {
             PhysicalLocationsList = Array.Empty<string>();
@@ -85,7 +87,6 @@ namespace MediaBrowser.Controller.Entities
             }
         }
 
-        private bool _requiresRefresh;
         public override bool RequiresRefresh()
         {
             var changed = base.RequiresRefresh() || _requiresRefresh;
@@ -105,11 +106,11 @@ namespace MediaBrowser.Controller.Entities
             return changed;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             ClearCache();
 
-            var changed = base.BeforeMetadataRefresh(replaceAllMetdata) || _requiresRefresh;
+            var changed = base.BeforeMetadataRefresh(replaceAllMetadata) || _requiresRefresh;
             _requiresRefresh = false;
             return changed;
         }
@@ -154,11 +155,11 @@ namespace MediaBrowser.Controller.Entities
             return base.GetNonCachedChildren(directoryService).Concat(_virtualChildren);
         }
 
-        protected override async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             ClearCache();
 
-            await base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService)
+            await base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken)
                 .ConfigureAwait(false);
 
             ClearCache();
@@ -184,7 +185,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="id">The id.</param>
         /// <returns>BaseItem.</returns>
-        /// <exception cref="ArgumentNullException">id</exception>
+        /// <exception cref="ArgumentNullException">The id is empty.</exception>
         public BaseItem FindVirtualChild(Guid id)
         {
             if (id.Equals(Guid.Empty))
diff --git a/MediaBrowser.Controller/Entities/Audio/Audio.cs b/MediaBrowser.Controller/Entities/Audio/Audio.cs
index 4c2b7cb7c..576ab67a2 100644
--- a/MediaBrowser.Controller/Entities/Audio/Audio.cs
+++ b/MediaBrowser.Controller/Entities/Audio/Audio.cs
@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text.Json.Serialization;
 using Jellyfin.Data.Enums;
@@ -82,19 +83,19 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("0000 - ") : "")
-                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ") : "") + Name;
+            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty)
+                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty) + Name;
         }
 
         public override List<string> GetUserDataKeys()
         {
             var list = base.GetUserDataKeys();
 
-            var songKey = IndexNumber.HasValue ? IndexNumber.Value.ToString("0000") : string.Empty;
+            var songKey = IndexNumber.HasValue ? IndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) : string.Empty;
 
             if (ParentIndexNumber.HasValue)
             {
-                songKey = ParentIndexNumber.Value.ToString("0000") + "-" + songKey;
+                songKey = ParentIndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) + "-" + songKey;
             }
 
             songKey += Name;
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
index 6101d3016..c0cd81110 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
@@ -94,7 +94,7 @@ namespace MediaBrowser.Controller.Entities.Audio
             return base.IsSaveLocalMetadataEnabled();
         }
 
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             if (IsAccessedByName)
             {
@@ -102,7 +102,7 @@ namespace MediaBrowser.Controller.Entities.Audio
                 return Task.CompletedTask;
             }
 
-            return base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService);
+            return base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken);
         }
 
         public override List<string> GetUserDataKeys()
@@ -114,7 +114,7 @@ namespace MediaBrowser.Controller.Entities.Audio
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -208,9 +208,9 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (IsAccessedByName)
             {
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
index b07d47ffd..a682a2e58 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
@@ -38,7 +38,7 @@ namespace MediaBrowser.Controller.Entities.Audio
         public override bool IsDisplayedAsFolder => true;
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -106,9 +106,9 @@ namespace MediaBrowser.Controller.Entities.Audio
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index ca5213273..6137ddbf7 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -92,7 +92,8 @@ namespace MediaBrowser.Controller.Entities
         public const string ShortsFolderName = "shorts";
         public const string FeaturettesFolderName = "featurettes";
 
-        public static readonly string[] AllExtrasTypesFolderNames = {
+        public static readonly string[] AllExtrasTypesFolderNames =
+        {
             ExtrasFolderName,
             BehindTheScenesFolderName,
             DeletedScenesFolderName,
@@ -177,7 +178,7 @@ namespace MediaBrowser.Controller.Entities
         public virtual bool AlwaysScanInternalMetadataPath => false;
 
         /// <summary>
-        /// Gets a value indicating whether this instance is in mixed folder.
+        /// Gets or sets a value indicating whether this instance is in mixed folder.
         /// </summary>
         /// <value><c>true</c> if this instance is in mixed folder; otherwise, <c>false</c>.</value>
         [JsonIgnore]
@@ -244,7 +245,7 @@ namespace MediaBrowser.Controller.Entities
         public ProgramAudio? Audio { get; set; }
 
         /// <summary>
-        /// Return the id that should be used to key display prefs for this item.
+        /// Gets the id that should be used to key display prefs for this item.
         /// Default is based on the type for everything except actual generic folders.
         /// </summary>
         /// <value>The display prefs id.</value>
@@ -280,7 +281,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         [JsonIgnore]
@@ -305,8 +306,11 @@ namespace MediaBrowser.Controller.Entities
         public string ServiceName { get; set; }
 
         /// <summary>
-        /// If this content came from an external service, the id of the content on that service.
+        /// Gets or sets the external id.
         /// </summary>
+        /// <remarks>
+        /// If this content came from an external service, the id of the content on that service.
+        /// </remarks>
         [JsonIgnore]
         public string ExternalId { get; set; }
 
@@ -330,7 +334,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Gets or sets the type of the location.
+        /// Gets the type of the location.
         /// </summary>
         /// <value>The type of the location.</value>
         [JsonIgnore]
@@ -339,9 +343,9 @@ namespace MediaBrowser.Controller.Entities
             get
             {
                 // if (IsOffline)
-                //{
+                // {
                 //    return LocationType.Offline;
-                //}
+                // }
 
                 var path = Path;
                 if (string.IsNullOrEmpty(path))
@@ -449,8 +453,11 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is just a helper for convenience.
+        /// Gets the primary image path.
         /// </summary>
+        /// <remarks>
+        /// This is just a helper for convenience.
+        /// </remarks>
         /// <value>The primary image path.</value>
         [JsonIgnore]
         public string PrimaryImagePath => this.GetImagePath(ImageType.Primary);
@@ -541,7 +548,7 @@ namespace MediaBrowser.Controller.Entities
         public DateTime DateLastRefreshed { get; set; }
 
         /// <summary>
-        /// The logger.
+        /// Gets or sets the logger.
         /// </summary>
         public static ILogger<BaseItem> Logger { get; set; }
 
@@ -613,7 +620,11 @@ namespace MediaBrowser.Controller.Entities
         public string ForcedSortName
         {
             get => _forcedSortName;
-            set { _forcedSortName = value; _sortName = null; }
+            set
+            {
+                _forcedSortName = value;
+                _sortName = null;
+            }
         }
 
         private string _sortName;
@@ -621,7 +632,7 @@ namespace MediaBrowser.Controller.Entities
         private Guid[] _themeVideoIds;
 
         /// <summary>
-        /// Gets the name of the sort.
+        /// Gets or sets the name of the sort.
         /// </summary>
         /// <value>The name of the sort.</value>
         [JsonIgnore]
@@ -659,14 +670,12 @@ namespace MediaBrowser.Controller.Entities
         {
             if (SourceType == SourceType.Channel)
             {
-                return System.IO.Path.Combine(basePath, "channels", ChannelId.ToString("N", CultureInfo.InvariantCulture), Id.ToString("N", CultureInfo.InvariantCulture));
+                return System.IO.Path.Join(basePath, "channels", ChannelId.ToString("N", CultureInfo.InvariantCulture), Id.ToString("N", CultureInfo.InvariantCulture));
             }
 
             ReadOnlySpan<char> idString = Id.ToString("N", CultureInfo.InvariantCulture);
 
-            basePath = System.IO.Path.Combine(basePath, "library");
-
-            return System.IO.Path.Join(basePath, idString.Slice(0, 2), idString);
+            return System.IO.Path.Join(basePath, "library", idString.Slice(0, 2), idString);
         }
 
         /// <summary>
@@ -848,7 +857,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// When the item first debuted. For movies this could be premiere date, episodes would be first aired
+        /// Gets or sets the date that the item first debuted. For movies this could be premiere date, episodes would be first aired.
         /// </summary>
         /// <value>The premiere date.</value>
         [JsonIgnore]
@@ -945,7 +954,7 @@ namespace MediaBrowser.Controller.Entities
         public int? ProductionYear { get; set; }
 
         /// <summary>
-        /// If the item is part of a series, this is it's number in the series.
+        /// Gets or sets the index number. If the item is part of a series, this is it's number in the series.
         /// This could be episode number, album track number, etc.
         /// </summary>
         /// <value>The index number.</value>
@@ -953,7 +962,7 @@ namespace MediaBrowser.Controller.Entities
         public int? IndexNumber { get; set; }
 
         /// <summary>
-        /// For an episode this could be the season number, or for a song this could be the disc number.
+        /// Gets or sets the parent index number. For an episode this could be the season number, or for a song this could be the disc number.
         /// </summary>
         /// <value>The parent index number.</value>
         [JsonIgnore]
@@ -1017,9 +1026,9 @@ namespace MediaBrowser.Controller.Entities
             }
 
             // if (!user.IsParentalScheduleAllowed())
-            //{
+            // {
             //    return PlayAccess.None;
-            //}
+            // }
 
             return PlayAccess.Full;
         }
@@ -1251,7 +1260,7 @@ namespace MediaBrowser.Controller.Entities
 
             // Support plex/xbmc convention
             files.AddRange(fileSystemChildren
-                .Where(i => !i.IsDirectory && string.Equals(FileSystem.GetFileNameWithoutExtension(i), ThemeSongFilename, StringComparison.OrdinalIgnoreCase)));
+                .Where(i => !i.IsDirectory && System.IO.Path.GetFileNameWithoutExtension(i.FullName.AsSpan()).Equals(ThemeSongFilename, StringComparison.OrdinalIgnoreCase)));
 
             return LibraryManager.ResolvePaths(files, directoryService, null, new LibraryOptions())
                 .OfType<Audio.Audio>()
@@ -1312,14 +1321,16 @@ namespace MediaBrowser.Controller.Entities
         {
             var extras = new List<Video>();
 
-            var folders = fileSystemChildren.Where(i => i.IsDirectory).ToArray();
+            var libraryOptions = new LibraryOptions();
+            var folders = fileSystemChildren.Where(i => i.IsDirectory).ToList();
             foreach (var extraFolderName in AllExtrasTypesFolderNames)
             {
                 var files = folders
                     .Where(i => string.Equals(i.Name, extraFolderName, StringComparison.OrdinalIgnoreCase))
                     .SelectMany(i => FileSystem.GetFiles(i.FullName));
 
-                extras.AddRange(LibraryManager.ResolvePaths(files, directoryService, null, new LibraryOptions())
+                // Re-using the same instance of LibraryOptions since it looks like it's never being altered.
+                extras.AddRange(LibraryManager.ResolvePaths(files, directoryService, null, libraryOptions)
                     .OfType<Video>()
                     .Select(item =>
                     {
@@ -1330,7 +1341,7 @@ namespace MediaBrowser.Controller.Entities
                         }
 
                         // Use some hackery to get the extra type based on foldername
-                        item.ExtraType = Enum.TryParse(extraFolderName.Replace(" ", string.Empty), true, out ExtraType extraType)
+                        item.ExtraType = Enum.TryParse(extraFolderName.Replace(" ", string.Empty, StringComparison.Ordinal), true, out ExtraType extraType)
                             ? extraType
                             : Model.Entities.ExtraType.Unknown;
 
@@ -1420,10 +1431,10 @@ namespace MediaBrowser.Controller.Entities
         /// Refreshes owned items such as trailers, theme videos, special features, etc.
         /// Returns true or false indicating if changes were found.
         /// </summary>
-        /// <param name="options"></param>
-        /// <param name="fileSystemChildren"></param>
-        /// <param name="cancellationToken"></param>
-        /// <returns></returns>
+        /// <param name="options">The metadata refresh options.</param>
+        /// <param name="fileSystemChildren">The list of filesystem children.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns><c>true</c> if any items have changed, else <c>false</c>.</returns>
         protected virtual async Task<bool> RefreshedOwnedItems(MetadataRefreshOptions options, List<FileSystemMetadata> fileSystemChildren, CancellationToken cancellationToken)
         {
             var themeSongsChanged = false;
@@ -1765,7 +1776,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="user">The user.</param>
         /// <returns><c>true</c> if [is parental allowed] [the specified user]; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentNullException">user</exception>
+        /// <exception cref="ArgumentNullException">If user is null.</exception>
         public bool IsParentalAllowed(User user)
         {
             if (user == null)
@@ -1910,7 +1921,7 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="user">The user.</param>
         /// <returns><c>true</c> if the specified user is visible; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentNullException">user</exception>
+        /// <exception cref="ArgumentNullException"><paramref name="user" /> is <c>null</c>.</exception>
         public virtual bool IsVisible(User user)
         {
             if (user == null)
@@ -2208,7 +2219,7 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="type">The type.</param>
         /// <param name="imageIndex">Index of the image.</param>
         /// <returns><c>true</c> if the specified type has image; otherwise, <c>false</c>.</returns>
-        /// <exception cref="ArgumentException">Backdrops should be accessed using Item.Backdrops</exception>
+        /// <exception cref="ArgumentException">Backdrops should be accessed using Item.Backdrops.</exception>
         public bool HasImage(ImageType type, int imageIndex)
         {
             return GetImageInfo(type, imageIndex) != null;
@@ -2316,7 +2327,7 @@ namespace MediaBrowser.Controller.Entities
                 .Where(i => i.IsLocalFile)
                 .Select(i => System.IO.Path.GetDirectoryName(i.Path))
                 .Distinct(StringComparer.OrdinalIgnoreCase)
-                .SelectMany(directoryService.GetFilePaths)
+                .SelectMany(path => directoryService.GetFilePaths(path))
                 .ToList();
 
             var deletedImages = ImageInfos
@@ -2337,9 +2348,8 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="imageType">Type of the image.</param>
         /// <param name="imageIndex">Index of the image.</param>
         /// <returns>System.String.</returns>
-        /// <exception cref="InvalidOperationException">
-        /// </exception>
-        /// <exception cref="ArgumentNullException">item</exception>
+        /// <exception cref="InvalidOperationException"> </exception>
+        /// <exception cref="ArgumentNullException">Item is null.</exception>
         public string GetImagePath(ImageType imageType, int imageIndex)
             => GetImageInfo(imageType, imageIndex)?.Path;
 
@@ -2426,7 +2436,15 @@ namespace MediaBrowser.Controller.Entities
                 throw new ArgumentException("No image info for chapter images");
             }
 
-            return ImageInfos.Where(i => i.Type == imageType);
+            // Yield return is more performant than LINQ Where on an Array
+            for (var i = 0; i < ImageInfos.Length; i++)
+            {
+                var imageInfo = ImageInfos[i];
+                if (imageInfo.Type == imageType)
+                {
+                    yield return imageInfo;
+                }
+            }
         }
 
         /// <summary>
@@ -2435,7 +2453,7 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="imageType">Type of the image.</param>
         /// <param name="images">The images.</param>
         /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns>
-        /// <exception cref="ArgumentException">Cannot call AddImages with chapter images</exception>
+        /// <exception cref="ArgumentException">Cannot call AddImages with chapter images.</exception>
         public bool AddImages(ImageType imageType, List<FileSystemMetadata> images)
         {
             if (imageType == ImageType.Chapter)
@@ -2458,7 +2476,7 @@ namespace MediaBrowser.Controller.Entities
                 }
 
                 var existing = existingImages
-                    .FirstOrDefault(i => string.Equals(i.Path, newImage.FullName, StringComparison.OrdinalIgnoreCase));
+                    .Find(i => string.Equals(i.Path, newImage.FullName, StringComparison.OrdinalIgnoreCase));
 
                 if (existing == null)
                 {
@@ -2489,8 +2507,7 @@ namespace MediaBrowser.Controller.Entities
                 var newImagePaths = images.Select(i => i.FullName).ToList();
 
                 var deleted = existingImages
-                    .Where(i => i.IsLocalFile && !newImagePaths.Contains(i.Path, StringComparer.OrdinalIgnoreCase) && !File.Exists(i.Path))
-                    .ToList();
+                    .FindAll(i => i.IsLocalFile && !newImagePaths.Contains(i.Path.AsSpan(), StringComparison.OrdinalIgnoreCase) && !File.Exists(i.Path));
 
                 if (deleted.Count > 0)
                 {
@@ -2519,10 +2536,11 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Gets the file system path to delete when the item is to be deleted.
         /// </summary>
-        /// <returns></returns>
+        /// <returns>The metadata for the deleted paths.</returns>
         public virtual IEnumerable<FileSystemMetadata> GetDeletePaths()
         {
-            return new[] {
+            return new[]
+            {
                 new FileSystemMetadata
                 {
                     FullName = Path,
@@ -2629,6 +2647,7 @@ namespace MediaBrowser.Controller.Entities
                 MetadataCountryCode = GetPreferredMetadataCountryCode(),
                 MetadataLanguage = GetPreferredMetadataLanguage(),
                 Name = GetNameForMetadataLookup(),
+                OriginalTitle = OriginalTitle,
                 ProviderIds = ProviderIds,
                 IndexNumber = IndexNumber,
                 ParentIndexNumber = ParentIndexNumber,
@@ -2645,7 +2664,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public virtual bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public virtual bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             _sortName = null;
 
@@ -2769,11 +2790,11 @@ namespace MediaBrowser.Controller.Entities
 
             // var parentId = Id;
             // if (!video.IsOwnedItem || video.ParentId != parentId)
-            //{
+            // {
             //    video.IsOwnedItem = true;
             //    video.ParentId = parentId;
             //    newOptions.ForceSave = true;
-            //}
+            // }
 
             if (video == null)
             {
@@ -2880,7 +2901,7 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Updates the official rating based on content and returns true or false indicating if it changed.
         /// </summary>
-        /// <returns></returns>
+        /// <returns><c>true</c> if the rating was updated; otherwise <c>false</c>.</returns>
         public bool UpdateRatingToItems(IList<BaseItem> children)
         {
             var currentOfficialRating = OfficialRating;
@@ -2896,7 +2917,9 @@ namespace MediaBrowser.Controller.Entities
 
             OfficialRating = ratings.FirstOrDefault() ?? currentOfficialRating;
 
-            return !string.Equals(currentOfficialRating ?? string.Empty, OfficialRating ?? string.Empty,
+            return !string.Equals(
+                currentOfficialRating ?? string.Empty,
+                OfficialRating ?? string.Empty,
                 StringComparison.OrdinalIgnoreCase);
         }
 
@@ -2993,7 +3016,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <inheritdoc />
-        public bool Equals(BaseItem item) => Object.Equals(Id, item?.Id);
+        public bool Equals(BaseItem other) => object.Equals(Id, other?.Id);
 
         /// <inheritdoc />
         public override int GetHashCode() => HashCode.Combine(Id);
diff --git a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
index c39b18891..89ad392a4 100644
--- a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
+++ b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
@@ -1,6 +1,3 @@
-#nullable disable
-
-#nullable enable
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Book.cs b/MediaBrowser.Controller/Entities/Book.cs
index 3d0370248..d75beb06d 100644
--- a/MediaBrowser.Controller/Entities/Book.cs
+++ b/MediaBrowser.Controller/Entities/Book.cs
@@ -12,6 +12,11 @@ namespace MediaBrowser.Controller.Entities
 {
     public class Book : BaseItem, IHasLookupInfo<BookInfo>, IHasSeries
     {
+        public Book()
+        {
+            this.RunTimeTicks = TimeSpan.TicksPerSecond;
+        }
+
         [JsonIgnore]
         public override string MediaType => Model.Entities.MediaType.Book;
 
@@ -28,11 +33,6 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public Guid SeriesId { get; set; }
 
-        public Book()
-        {
-            this.RunTimeTicks = TimeSpan.TicksPerSecond;
-        }
-
         public string FindSeriesSortName()
         {
             return SeriesName;
diff --git a/MediaBrowser.Controller/Entities/CollectionFolder.cs b/MediaBrowser.Controller/Entities/CollectionFolder.cs
index a86da29ce..4a721ca44 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -29,30 +29,45 @@ namespace MediaBrowser.Controller.Entities
     public class CollectionFolder : Folder, ICollectionFolder
     {
         private static readonly JsonSerializerOptions _jsonOptions = JsonDefaults.Options;
-        public static IXmlSerializer XmlSerializer { get; set; }
-
-        public static IServerApplicationHost ApplicationHost { get; set; }
+        private static readonly Dictionary<string, LibraryOptions> _libraryOptions = new Dictionary<string, LibraryOptions>();
+        private bool _requiresRefresh;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CollectionFolder"/> class.
+        /// </summary>
         public CollectionFolder()
         {
             PhysicalLocationsList = Array.Empty<string>();
             PhysicalFolderIds = Array.Empty<Guid>();
         }
 
+        public static IXmlSerializer XmlSerializer { get; set; }
+
+        public static IServerApplicationHost ApplicationHost { get; set; }
+
         [JsonIgnore]
         public override bool SupportsPlayedStatus => false;
 
         [JsonIgnore]
         public override bool SupportsInheritedParentImages => false;
 
+        public string CollectionType { get; set; }
+
+        /// <summary>
+        /// Gets the item's children.
+        /// </summary>
+        /// <remarks>
+        /// Our children are actually just references to the ones in the physical root...
+        /// </remarks>
+        /// <value>The actual children.</value>
+        [JsonIgnore]
+        public override IEnumerable<BaseItem> Children => GetActualChildren();
+
         public override bool CanDelete()
         {
             return false;
         }
 
-        public string CollectionType { get; set; }
-
-        private static readonly Dictionary<string, LibraryOptions> LibraryOptions = new Dictionary<string, LibraryOptions>();
         public LibraryOptions GetLibraryOptions()
         {
             return GetLibraryOptions(Path);
@@ -106,12 +121,12 @@ namespace MediaBrowser.Controller.Entities
 
         public static LibraryOptions GetLibraryOptions(string path)
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                if (!LibraryOptions.TryGetValue(path, out var options))
+                if (!_libraryOptions.TryGetValue(path, out var options))
                 {
                     options = LoadLibraryOptions(path);
-                    LibraryOptions[path] = options;
+                    _libraryOptions[path] = options;
                 }
 
                 return options;
@@ -120,9 +135,9 @@ namespace MediaBrowser.Controller.Entities
 
         public static void SaveLibraryOptions(string path, LibraryOptions options)
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                LibraryOptions[path] = options;
+                _libraryOptions[path] = options;
 
                 var clone = JsonSerializer.Deserialize<LibraryOptions>(JsonSerializer.SerializeToUtf8Bytes(options, _jsonOptions), _jsonOptions);
                 foreach (var mediaPath in clone.PathInfos)
@@ -139,15 +154,18 @@ namespace MediaBrowser.Controller.Entities
 
         public static void OnCollectionFolderChange()
         {
-            lock (LibraryOptions)
+            lock (_libraryOptions)
             {
-                LibraryOptions.Clear();
+                _libraryOptions.Clear();
             }
         }
 
         /// <summary>
-        /// Allow different display preferences for each collection folder.
+        /// Gets the display preferences id.
         /// </summary>
+        /// <remarks>
+        /// Allow different display preferences for each collection folder.
+        /// </remarks>
         /// <value>The display prefs id.</value>
         [JsonIgnore]
         public override Guid DisplayPreferencesId => Id;
@@ -155,21 +173,20 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public override string[] PhysicalLocations => PhysicalLocationsList;
 
+        public string[] PhysicalLocationsList { get; set; }
+
+        public Guid[] PhysicalFolderIds { get; set; }
+
         public override bool IsSaveLocalMetadataEnabled()
         {
             return true;
         }
 
-        public string[] PhysicalLocationsList { get; set; }
-
-        public Guid[] PhysicalFolderIds { get; set; }
-
         protected override FileSystemMetadata[] GetFileSystemChildren(IDirectoryService directoryService)
         {
             return CreateResolveArgs(directoryService, true).FileSystemChildren;
         }
 
-        private bool _requiresRefresh;
         public override bool RequiresRefresh()
         {
             var changed = base.RequiresRefresh() || _requiresRefresh;
@@ -201,9 +218,9 @@ namespace MediaBrowser.Controller.Entities
             return changed;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var changed = base.BeforeMetadataRefresh(replaceAllMetdata) || _requiresRefresh;
+            var changed = base.BeforeMetadataRefresh(replaceAllMetadata) || _requiresRefresh;
             _requiresRefresh = false;
             return changed;
         }
@@ -298,27 +315,20 @@ namespace MediaBrowser.Controller.Entities
 
         /// <summary>
         /// Compare our current children (presumably just read from the repo) with the current state of the file system and adjust for any changes
-        /// ***Currently does not contain logic to maintain items that are unavailable in the file system***
+        /// ***Currently does not contain logic to maintain items that are unavailable in the file system***.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
         /// <param name="refreshChildMetadata">if set to <c>true</c> [refresh child metadata].</param>
         /// <param name="refreshOptions">The refresh options.</param>
         /// <param name="directoryService">The directory service.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             return Task.CompletedTask;
         }
 
-        /// <summary>
-        /// Our children are actually just references to the ones in the physical root...
-        /// </summary>
-        /// <value>The actual children.</value>
-        [JsonIgnore]
-        public override IEnumerable<BaseItem> Children => GetActualChildren();
-
         public IEnumerable<BaseItem> GetActualChildren()
         {
             return GetPhysicalFolders(true).SelectMany(c => c.Children);
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index a59f5c6e4..541747422 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -37,6 +37,11 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class Folder : BaseItem
     {
+        public Folder()
+        {
+            LinkedChildren = Array.Empty<LinkedChild>();
+        }
+
         public static IUserViewManager UserViewManager { get; set; }
 
         /// <summary>
@@ -50,11 +55,6 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public DateTime? DateLastMediaAdded { get; set; }
 
-        public Folder()
-        {
-            LinkedChildren = Array.Empty<LinkedChild>();
-        }
-
         [JsonIgnore]
         public override bool SupportsThemeMedia => true;
 
@@ -86,6 +86,85 @@ namespace MediaBrowser.Controller.Entities
         [JsonIgnore]
         public virtual bool SupportsDateLastMediaAdded => false;
 
+        [JsonIgnore]
+        public override string FileNameWithoutExtension
+        {
+            get
+            {
+                if (IsFileProtocol)
+                {
+                    return System.IO.Path.GetFileName(Path);
+                }
+
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Gets the actual children.
+        /// </summary>
+        /// <value>The actual children.</value>
+        [JsonIgnore]
+        public virtual IEnumerable<BaseItem> Children => LoadChildren();
+
+        /// <summary>
+        /// Gets thread-safe access to all recursive children of this folder - without regard to user.
+        /// </summary>
+        /// <value>The recursive children.</value>
+        [JsonIgnore]
+        public IEnumerable<BaseItem> RecursiveChildren => GetRecursiveChildren();
+
+        [JsonIgnore]
+        protected virtual bool SupportsShortcutChildren => false;
+
+        protected virtual bool FilterLinkedChildrenPerUser => false;
+
+        [JsonIgnore]
+        protected override bool SupportsOwnedItems => base.SupportsOwnedItems || SupportsShortcutChildren;
+
+        [JsonIgnore]
+        public virtual bool SupportsUserDataFromChildren
+        {
+            get
+            {
+                // These are just far too slow.
+                if (this is ICollectionFolder)
+                {
+                    return false;
+                }
+
+                if (this is UserView)
+                {
+                    return false;
+                }
+
+                if (this is UserRootFolder)
+                {
+                    return false;
+                }
+
+                if (this is Channel)
+                {
+                    return false;
+                }
+
+                if (SourceType != SourceType.Library)
+                {
+                    return false;
+                }
+
+                if (this is IItemByName)
+                {
+                    if (this is not IHasDualAccess hasDualAccess || hasDualAccess.IsAccessedByName)
+                    {
+                        return false;
+                    }
+                }
+
+                return true;
+            }
+        }
+
         public override bool CanDelete()
         {
             if (IsRoot)
@@ -108,20 +187,6 @@ namespace MediaBrowser.Controller.Entities
             return baseResult;
         }
 
-        [JsonIgnore]
-        public override string FileNameWithoutExtension
-        {
-            get
-            {
-                if (IsFileProtocol)
-                {
-                    return System.IO.Path.GetFileName(Path);
-                }
-
-                return null;
-            }
-        }
-
         protected override bool IsAllowTagFilterEnforced()
         {
             if (this is ICollectionFolder)
@@ -137,16 +202,12 @@ namespace MediaBrowser.Controller.Entities
             return true;
         }
 
-        [JsonIgnore]
-        protected virtual bool SupportsShortcutChildren => false;
-
         /// <summary>
         /// Adds the child.
         /// </summary>
         /// <param name="item">The item.</param>
         /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task.</returns>
-        /// <exception cref="InvalidOperationException">Unable to add  + item.Name</exception>
+        /// <exception cref="InvalidOperationException">Unable to add  + item.Name.</exception>
         public void AddChild(BaseItem item, CancellationToken cancellationToken)
         {
             item.SetParent(this);
@@ -169,20 +230,6 @@ namespace MediaBrowser.Controller.Entities
             LibraryManager.CreateItem(item, this);
         }
 
-        /// <summary>
-        /// Gets the actual children.
-        /// </summary>
-        /// <value>The actual children.</value>
-        [JsonIgnore]
-        public virtual IEnumerable<BaseItem> Children => LoadChildren();
-
-        /// <summary>
-        /// thread-safe access to all recursive children of this folder - without regard to user.
-        /// </summary>
-        /// <value>The recursive children.</value>
-        [JsonIgnore]
-        public IEnumerable<BaseItem> RecursiveChildren => GetRecursiveChildren();
-
         public override bool IsVisible(User user)
         {
             if (this is ICollectionFolder && !(this is BasePluginFolder))
@@ -226,20 +273,20 @@ namespace MediaBrowser.Controller.Entities
 
         public Task ValidateChildren(IProgress<double> progress, CancellationToken cancellationToken)
         {
-            return ValidateChildren(progress, cancellationToken, new MetadataRefreshOptions(new DirectoryService(FileSystem)));
+            return ValidateChildren(progress, new MetadataRefreshOptions(new DirectoryService(FileSystem)), cancellationToken: cancellationToken);
         }
 
         /// <summary>
         /// Validates that the children of the folder still exist.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="metadataRefreshOptions">The metadata refresh options.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        public Task ValidateChildren(IProgress<double> progress, CancellationToken cancellationToken, MetadataRefreshOptions metadataRefreshOptions, bool recursive = true)
+        public Task ValidateChildren(IProgress<double> progress, MetadataRefreshOptions metadataRefreshOptions, bool recursive = true,  CancellationToken cancellationToken = default)
         {
-            return ValidateChildrenInternal(progress, cancellationToken, recursive, true, metadataRefreshOptions, metadataRefreshOptions.DirectoryService);
+            return ValidateChildrenInternal(progress, recursive, true, metadataRefreshOptions, metadataRefreshOptions.DirectoryService, cancellationToken);
         }
 
         private Dictionary<Guid, BaseItem> GetActualChildrenDictionary()
@@ -279,13 +326,13 @@ namespace MediaBrowser.Controller.Entities
         /// Validates the children internal.
         /// </summary>
         /// <param name="progress">The progress.</param>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <param name="recursive">if set to <c>true</c> [recursive].</param>
         /// <param name="refreshChildMetadata">if set to <c>true</c> [refresh child metadata].</param>
         /// <param name="refreshOptions">The refresh options.</param>
         /// <param name="directoryService">The directory service.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns>Task.</returns>
-        protected virtual async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected virtual async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             if (recursive)
             {
@@ -294,7 +341,7 @@ namespace MediaBrowser.Controller.Entities
 
             try
             {
-                await ValidateChildrenInternal2(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService).ConfigureAwait(false);
+                await ValidateChildrenInternal2(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken).ConfigureAwait(false);
             }
             finally
             {
@@ -305,7 +352,7 @@ namespace MediaBrowser.Controller.Entities
             }
         }
 
-        private async Task ValidateChildrenInternal2(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        private async Task ValidateChildrenInternal2(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             cancellationToken.ThrowIfCancellationRequested();
 
@@ -527,7 +574,7 @@ namespace MediaBrowser.Controller.Entities
         private Task ValidateSubFolders(IList<Folder> children, IDirectoryService directoryService, IProgress<double> progress, CancellationToken cancellationToken)
         {
             return RunTasks(
-                (folder, innerProgress) => folder.ValidateChildrenInternal(innerProgress, cancellationToken, true, false, null, directoryService),
+                (folder, innerProgress) => folder.ValidateChildrenInternal(innerProgress, true, false, null, directoryService, cancellationToken),
                 children,
                 progress,
                 cancellationToken);
@@ -940,7 +987,13 @@ namespace MediaBrowser.Controller.Entities
             }
             else
             {
-                items = GetChildren(user, true).Where(filter);
+                // need to pass this param to the children.
+                var childQuery = new InternalItemsQuery
+                {
+                    DisplayAlbumFolders = query.DisplayAlbumFolders
+                };
+
+                items = GetChildren(user, true, childQuery).Where(filter);
             }
 
             return PostFilterAndSort(items, query, true);
@@ -965,7 +1018,7 @@ namespace MediaBrowser.Controller.Entities
 
             if (!string.IsNullOrEmpty(query.NameStartsWith))
             {
-                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.OrdinalIgnoreCase));
+                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.CurrentCultureIgnoreCase));
             }
 
             if (!string.IsNullOrEmpty(query.NameLessThan))
@@ -1276,10 +1329,23 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Adds the children to list.
         /// </summary>
-        /// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
         private void AddChildren(User user, bool includeLinkedChildren, Dictionary<Guid, BaseItem> result, bool recursive, InternalItemsQuery query)
         {
-            foreach (var child in GetEligibleChildrenForRecursiveChildren(user))
+            // If Query.AlbumFolders is set, then enforce the format as per the db in that it permits sub-folders in music albums.
+            IEnumerable<BaseItem> children = null;
+            if ((query?.DisplayAlbumFolders ?? false) && (this is MusicAlbum))
+            {
+                children = Children;
+                query = null;
+            }
+
+            // If there are not sub-folders, proceed as normal.
+            if (children == null)
+            {
+                children = GetEligibleChildrenForRecursiveChildren(user);
+            }
+
+            foreach (var child in children)
             {
                 bool? isVisibleToUser = null;
 
@@ -1428,8 +1494,6 @@ namespace MediaBrowser.Controller.Entities
             return list;
         }
 
-        protected virtual bool FilterLinkedChildrenPerUser => false;
-
         public bool ContainsLinkedChildByItemId(Guid itemId)
         {
             var linkedChildren = LinkedChildren;
@@ -1530,9 +1594,6 @@ namespace MediaBrowser.Controller.Entities
                 .Where(i => i.Item2 != null);
         }
 
-        [JsonIgnore]
-        protected override bool SupportsOwnedItems => base.SupportsOwnedItems || SupportsShortcutChildren;
-
         protected override async Task<bool> RefreshedOwnedItems(MetadataRefreshOptions options, List<FileSystemMetadata> fileSystemChildren, CancellationToken cancellationToken)
         {
             var changesFound = false;
@@ -1553,7 +1614,8 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Refreshes the linked children.
         /// </summary>
-        /// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
+        /// <param name="fileSystemChildren">The enumerable of file system metadata.</param>
+        /// <returns><c>true</c> if the linked children were updated, <c>false</c> otherwise.</returns>
         protected virtual bool RefreshLinkedChildren(IEnumerable<FileSystemMetadata> fileSystemChildren)
         {
             if (SupportsShortcutChildren)
@@ -1696,51 +1758,6 @@ namespace MediaBrowser.Controller.Entities
             return !IsPlayed(user);
         }
 
-        [JsonIgnore]
-        public virtual bool SupportsUserDataFromChildren
-        {
-            get
-            {
-                // These are just far too slow.
-                if (this is ICollectionFolder)
-                {
-                    return false;
-                }
-
-                if (this is UserView)
-                {
-                    return false;
-                }
-
-                if (this is UserRootFolder)
-                {
-                    return false;
-                }
-
-                if (this is Channel)
-                {
-                    return false;
-                }
-
-                if (SourceType != SourceType.Library)
-                {
-                    return false;
-                }
-
-                var iItemByName = this as IItemByName;
-                if (iItemByName != null)
-                {
-                    var hasDualAccess = this as IHasDualAccess;
-                    if (hasDualAccess == null || hasDualAccess.IsAccessedByName)
-                    {
-                        return false;
-                    }
-                }
-
-                return true;
-            }
-        }
-
         public override void FillUserDataDtoValues(UserItemDataDto dto, UserItemData userData, BaseItemDto itemDto, User user, DtoOptions fields)
         {
             if (!SupportsUserDataFromChildren)
diff --git a/MediaBrowser.Controller/Entities/Genre.cs b/MediaBrowser.Controller/Entities/Genre.cs
index 7987f38a0..b80a5be3b 100644
--- a/MediaBrowser.Controller/Entities/Genre.cs
+++ b/MediaBrowser.Controller/Entities/Genre.cs
@@ -16,6 +16,23 @@ namespace MediaBrowser.Controller.Entities
     /// </summary>
     public class Genre : BaseItem, IItemByName
     {
+        /// <summary>
+        /// Gets the folder containing the item.
+        /// If the item is a folder, it returns the folder itself.
+        /// </summary>
+        /// <value>The containing folder path.</value>
+        [JsonIgnore]
+        public override string ContainingFolderPath => Path;
+
+        [JsonIgnore]
+        public override bool IsDisplayedAsFolder => true;
+
+        [JsonIgnore]
+        public override bool SupportsAncestors => false;
+
+        [JsonIgnore]
+        public override bool SupportsPeople => false;
+
         public override List<string> GetUserDataKeys()
         {
             var list = base.GetUserDataKeys();
@@ -34,20 +51,6 @@ namespace MediaBrowser.Controller.Entities
             return 1;
         }
 
-        /// <summary>
-        /// Returns the folder containing the item.
-        /// If the item is a folder, it returns the folder itself.
-        /// </summary>
-        /// <value>The containing folder path.</value>
-        [JsonIgnore]
-        public override string ContainingFolderPath => Path;
-
-        [JsonIgnore]
-        public override bool IsDisplayedAsFolder => true;
-
-        [JsonIgnore]
-        public override bool SupportsAncestors => false;
-
         public override bool IsSaveLocalMetadataEnabled()
         {
             return true;
@@ -72,9 +75,6 @@ namespace MediaBrowser.Controller.Entities
             return LibraryManager.GetItemList(query);
         }
 
-        [JsonIgnore]
-        public override bool SupportsPeople => false;
-
         public static string GetPath(string name)
         {
             return GetPath(name, true);
@@ -108,11 +108,13 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is called before any metadata refresh and returns true or false indicating if changes were made.
+        /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/IHasScreenshots.cs b/MediaBrowser.Controller/Entities/IHasScreenshots.cs
index b027a0cb1..ae01c223e 100644
--- a/MediaBrowser.Controller/Entities/IHasScreenshots.cs
+++ b/MediaBrowser.Controller/Entities/IHasScreenshots.cs
@@ -1,7 +1,7 @@
 namespace MediaBrowser.Controller.Entities
 {
     /// <summary>
-    /// Interface IHasScreenshots.
+    /// The item has screenshots.
     /// </summary>
     public interface IHasScreenshots
     {
diff --git a/MediaBrowser.Controller/Entities/IHasSeries.cs b/MediaBrowser.Controller/Entities/IHasSeries.cs
index 64d769d5b..5f774bbde 100644
--- a/MediaBrowser.Controller/Entities/IHasSeries.cs
+++ b/MediaBrowser.Controller/Entities/IHasSeries.cs
@@ -9,7 +9,7 @@ namespace MediaBrowser.Controller.Entities
     public interface IHasSeries
     {
         /// <summary>
-        /// Gets the name of the series.
+        /// Gets or sets the name of the series.
         /// </summary>
         /// <value>The name of the series.</value>
         string SeriesName { get; set; }
diff --git a/MediaBrowser.Controller/Entities/IHasShares.cs b/MediaBrowser.Controller/Entities/IHasShares.cs
new file mode 100644
index 000000000..bdde744a3
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/IHasShares.cs
@@ -0,0 +1,11 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+namespace MediaBrowser.Controller.Entities
+{
+    public interface IHasShares
+    {
+        Share[] Shares { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
index c06021029..ebaf5506d 100644
--- a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;
@@ -20,9 +18,9 @@ namespace MediaBrowser.Controller.Entities
 
         public int? Limit { get; set; }
 
-        public User User { get; set; }
+        public User? User { get; set; }
 
-        public BaseItem SimilarTo { get; set; }
+        public BaseItem? SimilarTo { get; set; }
 
         public bool? IsFolder { get; set; }
 
@@ -58,23 +56,23 @@ namespace MediaBrowser.Controller.Entities
 
         public bool? CollapseBoxSetItems { get; set; }
 
-        public string NameStartsWithOrGreater { get; set; }
+        public string? NameStartsWithOrGreater { get; set; }
 
-        public string NameStartsWith { get; set; }
+        public string? NameStartsWith { get; set; }
 
-        public string NameLessThan { get; set; }
+        public string? NameLessThan { get; set; }
 
-        public string NameContains { get; set; }
+        public string? NameContains { get; set; }
 
-        public string MinSortName { get; set; }
+        public string? MinSortName { get; set; }
 
-        public string PresentationUniqueKey { get; set; }
+        public string? PresentationUniqueKey { get; set; }
 
-        public string Path { get; set; }
+        public string? Path { get; set; }
 
-        public string Name { get; set; }
+        public string? Name { get; set; }
 
-        public string Person { get; set; }
+        public string? Person { get; set; }
 
         public Guid[] PersonIds { get; set; }
 
@@ -82,7 +80,7 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid[] ExcludeItemIds { get; set; }
 
-        public string AdjacentTo { get; set; }
+        public string? AdjacentTo { get; set; }
 
         public string[] PersonTypes { get; set; }
 
@@ -182,13 +180,13 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid ParentId { get; set; }
 
-        public string ParentType { get; set; }
+        public string? ParentType { get; set; }
 
         public Guid[] AncestorIds { get; set; }
 
         public Guid[] TopParentIds { get; set; }
 
-        public BaseItem Parent
+        public BaseItem? Parent
         {
             set
             {
@@ -213,9 +211,9 @@ namespace MediaBrowser.Controller.Entities
 
         public SeriesStatus[] SeriesStatuses { get; set; }
 
-        public string ExternalSeriesId { get; set; }
+        public string? ExternalSeriesId { get; set; }
 
-        public string ExternalId { get; set; }
+        public string? ExternalId { get; set; }
 
         public Guid[] AlbumIds { get; set; }
 
@@ -223,9 +221,9 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid[] ExcludeArtistIds { get; set; }
 
-        public string AncestorWithPresentationUniqueKey { get; set; }
+        public string? AncestorWithPresentationUniqueKey { get; set; }
 
-        public string SeriesPresentationUniqueKey { get; set; }
+        public string? SeriesPresentationUniqueKey { get; set; }
 
         public bool GroupByPresentationUniqueKey { get; set; }
 
@@ -235,7 +233,7 @@ namespace MediaBrowser.Controller.Entities
 
         public bool ForceDirect { get; set; }
 
-        public Dictionary<string, string> ExcludeProviderIds { get; set; }
+        public Dictionary<string, string>? ExcludeProviderIds { get; set; }
 
         public bool EnableGroupByMetadataKey { get; set; }
 
@@ -253,13 +251,13 @@ namespace MediaBrowser.Controller.Entities
 
         public int MinSimilarityScore { get; set; }
 
-        public string HasNoAudioTrackWithLanguage { get; set; }
+        public string? HasNoAudioTrackWithLanguage { get; set; }
 
-        public string HasNoInternalSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoInternalSubtitleTrackWithLanguage { get; set; }
 
-        public string HasNoExternalSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoExternalSubtitleTrackWithLanguage { get; set; }
 
-        public string HasNoSubtitleTrackWithLanguage { get; set; }
+        public string? HasNoSubtitleTrackWithLanguage { get; set; }
 
         public bool? IsDeadArtist { get; set; }
 
@@ -267,6 +265,11 @@ namespace MediaBrowser.Controller.Entities
 
         public bool? IsDeadPerson { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether album sub-folders should be returned if they exist.
+        /// </summary>
+        public bool? DisplayAlbumFolders { get; set; }
+
         public InternalItemsQuery()
         {
             AlbumArtistIds = Array.Empty<Guid>();
@@ -283,12 +286,10 @@ namespace MediaBrowser.Controller.Entities
             ExcludeInheritedTags = Array.Empty<string>();
             ExcludeItemIds = Array.Empty<Guid>();
             ExcludeItemTypes = Array.Empty<string>();
-            ExcludeProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             ExcludeTags = Array.Empty<string>();
             GenreIds = Array.Empty<Guid>();
             Genres = Array.Empty<string>();
             GroupByPresentationUniqueKey = true;
-            HasAnyProviderId = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             ImageTypes = Array.Empty<ImageType>();
             IncludeItemTypes = Array.Empty<string>();
             ItemIds = Array.Empty<Guid>();
@@ -309,32 +310,33 @@ namespace MediaBrowser.Controller.Entities
             Years = Array.Empty<int>();
         }
 
-        public InternalItemsQuery(User user)
+        public InternalItemsQuery(User? user)
             : this()
         {
-            SetUser(user);
+            if (user != null)
+            {
+                SetUser(user);
+            }
         }
 
         public void SetUser(User user)
         {
-            if (user != null)
-            {
-                MaxParentalRating = user.MaxParentalAgeRating;
+            MaxParentalRating = user.MaxParentalAgeRating;
 
-                if (MaxParentalRating.HasValue)
-                {
-                    BlockUnratedItems = user.GetPreference(PreferenceKind.BlockUnratedItems)
-                        .Where(i => i != UnratedItem.Other.ToString())
-                        .Select(e => Enum.Parse<UnratedItem>(e, true)).ToArray();
-                }
+            if (MaxParentalRating.HasValue)
+            {
+                string other = UnratedItem.Other.ToString();
+                BlockUnratedItems = user.GetPreference(PreferenceKind.BlockUnratedItems)
+                    .Where(i => i != other)
+                    .Select(e => Enum.Parse<UnratedItem>(e, true)).ToArray();
+            }
 
-                ExcludeInheritedTags = user.GetPreference(PreferenceKind.BlockedTags);
+            ExcludeInheritedTags = user.GetPreference(PreferenceKind.BlockedTags);
 
-                User = user;
-            }
+            User = user;
         }
 
-        public Dictionary<string, string> HasAnyProviderId { get; set; }
+        public Dictionary<string, string>? HasAnyProviderId { get; set; }
 
         public Guid[] AlbumArtistIds { get; set; }
 
@@ -356,8 +358,8 @@ namespace MediaBrowser.Controller.Entities
 
         public int? MinWidth { get; set; }
 
-        public string SearchTerm { get; set; }
+        public string? SearchTerm { get; set; }
 
-        public string SeriesTimerId { get; set; }
+        public string? SeriesTimerId { get; set; }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
index b2d6a4609..3e1d89274 100644
--- a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
@@ -3,12 +3,24 @@
 #pragma warning disable CS1591
 
 using System;
+using System.Collections.Generic;
 using Jellyfin.Data.Entities;
 
 namespace MediaBrowser.Controller.Entities
 {
     public class InternalPeopleQuery
     {
+        public InternalPeopleQuery()
+         : this(Array.Empty<string>(), Array.Empty<string>())
+        {
+        }
+
+        public InternalPeopleQuery(IReadOnlyList<string> personTypes, IReadOnlyList<string> excludePersonTypes)
+        {
+            PersonTypes = personTypes;
+            ExcludePersonTypes = excludePersonTypes;
+        }
+
         /// <summary>
         /// Gets or sets the maximum number of items the query should return.
         /// </summary>
@@ -16,9 +28,9 @@ namespace MediaBrowser.Controller.Entities
 
         public Guid ItemId { get; set; }
 
-        public string[] PersonTypes { get; set; }
+        public IReadOnlyList<string> PersonTypes { get; }
 
-        public string[] ExcludePersonTypes { get; set; }
+        public IReadOnlyList<string> ExcludePersonTypes { get; }
 
         public int? MaxListOrder { get; set; }
 
@@ -29,11 +41,5 @@ namespace MediaBrowser.Controller.Entities
         public User User { get; set; }
 
         public bool? IsFavorite { get; set; }
-
-        public InternalPeopleQuery()
-        {
-            PersonTypes = Array.Empty<string>();
-            ExcludePersonTypes = Array.Empty<string>();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChild.cs b/MediaBrowser.Controller/Entities/LinkedChild.cs
index 01c0a9339..fd5fef3dc 100644
--- a/MediaBrowser.Controller/Entities/LinkedChild.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChild.cs
@@ -3,15 +3,18 @@
 #pragma warning disable CS1591
 
 using System;
-using System.Collections.Generic;
 using System.Globalization;
 using System.Text.Json.Serialization;
-using MediaBrowser.Model.IO;
 
 namespace MediaBrowser.Controller.Entities
 {
     public class LinkedChild
     {
+        public LinkedChild()
+        {
+            Id = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
+        }
+
         public string Path { get; set; }
 
         public LinkedChildType Type { get; set; }
@@ -22,7 +25,7 @@ namespace MediaBrowser.Controller.Entities
         public string Id { get; set; }
 
         /// <summary>
-        /// Serves as a cache.
+        /// Gets or sets the linked item id.
         /// </summary>
         public Guid? ItemId { get; set; }
 
@@ -41,41 +44,5 @@ namespace MediaBrowser.Controller.Entities
 
             return child;
         }
-
-        public LinkedChild()
-        {
-            Id = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
-        }
-    }
-
-    public enum LinkedChildType
-    {
-        Manual = 0,
-        Shortcut = 1
-    }
-
-    public class LinkedChildComparer : IEqualityComparer<LinkedChild>
-    {
-        private readonly IFileSystem _fileSystem;
-
-        public LinkedChildComparer(IFileSystem fileSystem)
-        {
-            _fileSystem = fileSystem;
-        }
-
-        public bool Equals(LinkedChild x, LinkedChild y)
-        {
-            if (x.Type == y.Type)
-            {
-                return _fileSystem.AreEqual(x.Path, y.Path);
-            }
-
-            return false;
-        }
-
-        public int GetHashCode(LinkedChild obj)
-        {
-            return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode();
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
new file mode 100644
index 000000000..4e58e2942
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
@@ -0,0 +1,35 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+using System;
+using System.Collections.Generic;
+using MediaBrowser.Model.IO;
+
+namespace MediaBrowser.Controller.Entities
+{
+    public class LinkedChildComparer : IEqualityComparer<LinkedChild>
+    {
+        private readonly IFileSystem _fileSystem;
+
+        public LinkedChildComparer(IFileSystem fileSystem)
+        {
+            _fileSystem = fileSystem;
+        }
+
+        public bool Equals(LinkedChild x, LinkedChild y)
+        {
+            if (x.Type == y.Type)
+            {
+                return _fileSystem.AreEqual(x.Path, y.Path);
+            }
+
+            return false;
+        }
+
+        public int GetHashCode(LinkedChild obj)
+        {
+            return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode(StringComparison.Ordinal);
+        }
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/LinkedChildType.cs b/MediaBrowser.Controller/Entities/LinkedChildType.cs
new file mode 100644
index 000000000..9ddb7b620
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/LinkedChildType.cs
@@ -0,0 +1,18 @@
+namespace MediaBrowser.Controller.Entities
+{
+    /// <summary>
+    /// The linked child type.
+    /// </summary>
+    public enum LinkedChildType
+    {
+        /// <summary>
+        /// Manually linked child.
+        /// </summary>
+        Manual = 0,
+
+        /// <summary>
+        /// Shortcut linked child.
+        /// </summary>
+        Shortcut = 1
+    }
+}
\ No newline at end of file
diff --git a/MediaBrowser.Controller/Entities/Movies/Movie.cs b/MediaBrowser.Controller/Entities/Movies/Movie.cs
index 64d60c2e9..b54bbf5eb 100644
--- a/MediaBrowser.Controller/Entities/Movies/Movie.cs
+++ b/MediaBrowser.Controller/Entities/Movies/Movie.cs
@@ -144,9 +144,9 @@ namespace MediaBrowser.Controller.Entities.Movies
         }
 
         /// <inheritdoc />
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/MusicVideo.cs b/MediaBrowser.Controller/Entities/MusicVideo.cs
index f42e7723c..237ad5198 100644
--- a/MediaBrowser.Controller/Entities/MusicVideo.cs
+++ b/MediaBrowser.Controller/Entities/MusicVideo.cs
@@ -13,15 +13,15 @@ namespace MediaBrowser.Controller.Entities
 {
     public class MusicVideo : Video, IHasArtist, IHasMusicGenres, IHasLookupInfo<MusicVideoInfo>
     {
-        /// <inheritdoc />
-        [JsonIgnore]
-        public IReadOnlyList<string> Artists { get; set; }
-
         public MusicVideo()
         {
             Artists = Array.Empty<string>();
         }
 
+        /// <inheritdoc />
+        [JsonIgnore]
+        public IReadOnlyList<string> Artists { get; set; }
+
         public override UnratedItem GetBlockUnratedType()
         {
             return UnratedItem.Music;
@@ -36,9 +36,9 @@ namespace MediaBrowser.Controller.Entities
             return info;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/Person.cs b/MediaBrowser.Controller/Entities/Person.cs
index d9ff55362..913f76d3b 100644
--- a/MediaBrowser.Controller/Entities/Person.cs
+++ b/MediaBrowser.Controller/Entities/Person.cs
@@ -50,7 +50,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -67,6 +67,9 @@ namespace MediaBrowser.Controller.Entities
             return true;
         }
 
+        /// <summary>
+        /// Gets a value indicating whether to enable alpha numeric sorting.
+        /// </summary>
         [JsonIgnore]
         public override bool EnableAlphaNumericSorting => false;
 
@@ -126,9 +129,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/Share.cs b/MediaBrowser.Controller/Entities/Share.cs
index 7e4ec1830..64f446eef 100644
--- a/MediaBrowser.Controller/Entities/Share.cs
+++ b/MediaBrowser.Controller/Entities/Share.cs
@@ -4,11 +4,6 @@
 
 namespace MediaBrowser.Controller.Entities
 {
-    public interface IHasShares
-    {
-        Share[] Shares { get; set; }
-    }
-
     public class Share
     {
         public string UserId { get; set; }
diff --git a/MediaBrowser.Controller/Entities/Studio.cs b/MediaBrowser.Controller/Entities/Studio.cs
index ae1d10447..6fd0a6c6c 100644
--- a/MediaBrowser.Controller/Entities/Studio.cs
+++ b/MediaBrowser.Controller/Entities/Studio.cs
@@ -29,7 +29,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -105,9 +105,9 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))
diff --git a/MediaBrowser.Controller/Entities/TV/Episode.cs b/MediaBrowser.Controller/Entities/TV/Episode.cs
index 2724bd9b3..31c179bca 100644
--- a/MediaBrowser.Controller/Entities/TV/Episode.cs
+++ b/MediaBrowser.Controller/Entities/TV/Episode.cs
@@ -34,7 +34,7 @@ namespace MediaBrowser.Controller.Entities.TV
         public IReadOnlyList<Guid> RemoteTrailerIds { get; set; }
 
         /// <summary>
-        /// Gets the season in which it aired.
+        /// Gets or sets the season in which it aired.
         /// </summary>
         /// <value>The aired season.</value>
         public int? AirsBeforeSeasonNumber { get; set; }
@@ -44,7 +44,7 @@ namespace MediaBrowser.Controller.Entities.TV
         public int? AirsBeforeEpisodeNumber { get; set; }
 
         /// <summary>
-        /// This is the ending episode number for double episodes.
+        /// Gets or sets the ending episode number for double episodes.
         /// </summary>
         /// <value>The index number.</value>
         public int? IndexNumberEnd { get; set; }
@@ -116,7 +116,7 @@ namespace MediaBrowser.Controller.Entities.TV
         }
 
         /// <summary>
-        /// This Episode's Series Instance.
+        /// Gets the Episode's Series Instance.
         /// </summary>
         /// <value>The series.</value>
         [JsonIgnore]
@@ -218,8 +218,8 @@ namespace MediaBrowser.Controller.Entities.TV
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("000 - ") : "")
-                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ") : "") + Name;
+            return (ParentIndexNumber != null ? ParentIndexNumber.Value.ToString("000 - ", CultureInfo.InvariantCulture) : string.Empty)
+                    + (IndexNumber != null ? IndexNumber.Value.ToString("0000 - ", CultureInfo.InvariantCulture) : string.Empty) + Name;
         }
 
         /// <summary>
@@ -261,6 +261,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         [JsonIgnore]
         public Guid SeasonId { get; set; }
+
         [JsonIgnore]
         public Guid SeriesId { get; set; }
 
@@ -286,7 +287,8 @@ namespace MediaBrowser.Controller.Entities.TV
 
         public override IEnumerable<FileSystemMetadata> GetDeletePaths()
         {
-            return new[] {
+            return new[]
+            {
                 new FileSystemMetadata
                 {
                     FullName = Path,
@@ -318,9 +320,9 @@ namespace MediaBrowser.Controller.Entities.TV
             return id;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!IsLocked)
             {
@@ -328,7 +330,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 {
                     try
                     {
-                        if (LibraryManager.FillMissingEpisodeNumbersFromPath(this, replaceAllMetdata))
+                        if (LibraryManager.FillMissingEpisodeNumbersFromPath(this, replaceAllMetadata))
                         {
                             hasChanges = true;
                         }
diff --git a/MediaBrowser.Controller/Entities/TV/Season.cs b/MediaBrowser.Controller/Entities/TV/Season.cs
index ad3e0fe8d..aa62bb35b 100644
--- a/MediaBrowser.Controller/Entities/TV/Season.cs
+++ b/MediaBrowser.Controller/Entities/TV/Season.cs
@@ -81,7 +81,7 @@ namespace MediaBrowser.Controller.Entities.TV
         }
 
         /// <summary>
-        /// This Episode's Series Instance.
+        /// Gets this Episode's Series Instance.
         /// </summary>
         /// <value>The series.</value>
         [JsonIgnore]
@@ -122,7 +122,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 var series = Series;
                 if (series != null)
                 {
-                    return series.PresentationUniqueKey + "-" + (IndexNumber ?? 0).ToString("000");
+                    return series.PresentationUniqueKey + "-" + (IndexNumber ?? 0).ToString("000", CultureInfo.InvariantCulture);
                 }
             }
 
@@ -135,7 +135,7 @@ namespace MediaBrowser.Controller.Entities.TV
         /// <returns>System.String.</returns>
         protected override string CreateSortName()
         {
-            return IndexNumber != null ? IndexNumber.Value.ToString("0000") : Name;
+            return IndexNumber != null ? IndexNumber.Value.ToString("0000", CultureInfo.InvariantCulture) : Name;
         }
 
         protected override QueryResult<BaseItem> GetItemsInternal(InternalItemsQuery query)
@@ -242,9 +242,9 @@ namespace MediaBrowser.Controller.Entities.TV
         /// This is called before any metadata refresh and returns true or false indicating if changes were made.
         /// </summary>
         /// <returns><c>true</c> if XXXX, <c>false</c> otherwise.</returns>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!IndexNumber.HasValue && !string.IsNullOrEmpty(Path))
             {
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index ded825abc..44d07b4a4 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -59,8 +59,11 @@ namespace MediaBrowser.Controller.Entities.TV
         public IReadOnlyList<Guid> RemoteTrailerIds { get; set; }
 
         /// <summary>
-        /// airdate, dvd or absolute.
+        /// Gets or sets the display order.
         /// </summary>
+        /// <remarks>
+        /// Valid options are airdate, dvd or absolute.
+        /// </remarks>
         public string DisplayOrder { get; set; }
 
         /// <summary>
diff --git a/MediaBrowser.Controller/Entities/Trailer.cs b/MediaBrowser.Controller/Entities/Trailer.cs
index b086b5906..732b45521 100644
--- a/MediaBrowser.Controller/Entities/Trailer.cs
+++ b/MediaBrowser.Controller/Entities/Trailer.cs
@@ -45,9 +45,9 @@ namespace MediaBrowser.Controller.Entities
             return info;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (!ProductionYear.HasValue)
             {
diff --git a/MediaBrowser.Controller/Entities/UserItemData.cs b/MediaBrowser.Controller/Entities/UserItemData.cs
index f60359c01..6ab2116d7 100644
--- a/MediaBrowser.Controller/Entities/UserItemData.cs
+++ b/MediaBrowser.Controller/Entities/UserItemData.cs
@@ -96,7 +96,7 @@ namespace MediaBrowser.Controller.Entities
         public const double MinLikeValue = 6.5;
 
         /// <summary>
-        /// This is an interpreted property to indicate likes or dislikes
+        /// Gets or sets a value indicating whether the item is liked or not.
         /// This should never be serialized.
         /// </summary>
         /// <value><c>null</c> if [likes] contains no value, <c>true</c> if [likes]; otherwise, <c>false</c>.</value>
diff --git a/MediaBrowser.Controller/Entities/UserRootFolder.cs b/MediaBrowser.Controller/Entities/UserRootFolder.cs
index e492740ed..2b15a52f0 100644
--- a/MediaBrowser.Controller/Entities/UserRootFolder.cs
+++ b/MediaBrowser.Controller/Entities/UserRootFolder.cs
@@ -23,6 +23,7 @@ namespace MediaBrowser.Controller.Entities
     {
         private List<Guid> _childrenIds = null;
         private readonly object _childIdsLock = new object();
+
         protected override List<BaseItem> LoadChildren()
         {
             lock (_childIdsLock)
@@ -87,10 +88,10 @@ namespace MediaBrowser.Controller.Entities
             return list;
         }
 
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
             ClearCache();
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             if (string.Equals("default", Name, StringComparison.OrdinalIgnoreCase))
             {
@@ -108,11 +109,11 @@ namespace MediaBrowser.Controller.Entities
             return base.GetNonCachedChildren(directoryService);
         }
 
-        protected override async Task ValidateChildrenInternal(IProgress<double> progress, CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService)
+        protected override async Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, MetadataRefreshOptions refreshOptions, IDirectoryService directoryService, CancellationToken cancellationToken)
         {
             ClearCache();
 
-            await base.ValidateChildrenInternal(progress, cancellationToken, recursive, refreshChildMetadata, refreshOptions, directoryService)
+            await base.ValidateChildrenInternal(progress, recursive, refreshChildMetadata, refreshOptions, directoryService, cancellationToken)
                 .ConfigureAwait(false);
 
             ClearCache();
diff --git a/MediaBrowser.Controller/Entities/UserView.cs b/MediaBrowser.Controller/Entities/UserView.cs
index 0dfde2766..57dc9b59b 100644
--- a/MediaBrowser.Controller/Entities/UserView.cs
+++ b/MediaBrowser.Controller/Entities/UserView.cs
@@ -15,13 +15,19 @@ namespace MediaBrowser.Controller.Entities
 {
     public class UserView : Folder, IHasCollectionType
     {
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the view type.
+        /// </summary>
         public string ViewType { get; set; }
 
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the display parent id.
+        /// </summary>
         public new Guid DisplayParentId { get; set; }
 
-        /// <inheritdoc />
+        /// <summary>
+        /// Gets or sets the user id.
+        /// </summary>
         public Guid? UserId { get; set; }
 
         public static ITVSeriesManager TVSeriesManager;
@@ -110,10 +116,10 @@ namespace MediaBrowser.Controller.Entities
             return GetChildren(user, false);
         }
 
-        private static string[] UserSpecificViewTypes = new string[]
-            {
-                Model.Entities.CollectionType.Playlists
-            };
+        private static readonly string[] UserSpecificViewTypes = new string[]
+        {
+            Model.Entities.CollectionType.Playlists
+        };
 
         public static bool IsUserSpecific(Folder folder)
         {
@@ -166,7 +172,7 @@ namespace MediaBrowser.Controller.Entities
             return OriginalFolderViewTypes.Contains(viewType ?? string.Empty, StringComparer.OrdinalIgnoreCase);
         }
 
-        protected override Task ValidateChildrenInternal(IProgress<double> progress, System.Threading.CancellationToken cancellationToken, bool recursive, bool refreshChildMetadata, Providers.MetadataRefreshOptions refreshOptions, Providers.IDirectoryService directoryService)
+        protected override Task ValidateChildrenInternal(IProgress<double> progress, bool recursive, bool refreshChildMetadata, Providers.MetadataRefreshOptions refreshOptions, Providers.IDirectoryService directoryService, System.Threading.CancellationToken cancellationToken)
         {
             return Task.CompletedTask;
         }
diff --git a/MediaBrowser.Controller/Entities/UserViewBuilder.cs b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
index 15a4573c2..add734f62 100644
--- a/MediaBrowser.Controller/Entities/UserViewBuilder.cs
+++ b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
@@ -55,12 +55,12 @@ namespace MediaBrowser.Controller.Entities
             // if (query.IncludeItemTypes != null &&
             //    query.IncludeItemTypes.Length == 1 &&
             //    string.Equals(query.IncludeItemTypes[0], "Playlist", StringComparison.OrdinalIgnoreCase))
-            //{
+            // {
             //    if (!string.Equals(viewType, CollectionType.Playlists, StringComparison.OrdinalIgnoreCase))
             //    {
             //        return await FindPlaylists(queryParent, user, query).ConfigureAwait(false);
             //    }
-            //}
+            // }
 
             switch (viewType)
             {
@@ -344,12 +344,14 @@ namespace MediaBrowser.Controller.Entities
             var parentFolders = GetMediaFolders(parent, query.User, new[] { CollectionType.TvShows, string.Empty });
 
             var result = _tvSeriesManager.GetNextUp(
-            new NextUpQuery
-            {
-                Limit = query.Limit,
-                StartIndex = query.StartIndex,
-                UserId = query.User.Id
-            }, parentFolders, query.DtoOptions);
+                new NextUpQuery
+                {
+                    Limit = query.Limit,
+                    StartIndex = query.StartIndex,
+                    UserId = query.User.Id
+                },
+                parentFolders,
+                query.DtoOptions);
 
             return result;
         }
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index 723027a88..d05b5df2f 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -482,7 +482,8 @@ namespace MediaBrowser.Controller.Entities
         {
             if (!IsInMixedFolder)
             {
-                return new[] {
+                return new[]
+                {
                     new FileSystemMetadata
                     {
                         FullName = ContainingFolderPath,
diff --git a/MediaBrowser.Controller/Entities/Year.cs b/MediaBrowser.Controller/Entities/Year.cs
index 4d84a151a..f268bc939 100644
--- a/MediaBrowser.Controller/Entities/Year.cs
+++ b/MediaBrowser.Controller/Entities/Year.cs
@@ -24,7 +24,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// Returns the folder containing the item.
+        /// Gets the folder containing the item.
         /// If the item is a folder, it returns the folder itself.
         /// </summary>
         /// <value>The containing folder path.</value>
@@ -112,11 +112,13 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
-        /// This is called before any metadata refresh and returns true or false indicating if changes were made.
+        /// This is called before any metadata refresh and returns true if changes were made.
         /// </summary>
-        public override bool BeforeMetadataRefresh(bool replaceAllMetdata)
+        /// <param name="replaceAllMetadata">Whether to replace all metadata.</param>
+        /// <returns>true if the item has change, else false.</returns>
+        public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
-            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetdata);
+            var hasChanges = base.BeforeMetadataRefresh(replaceAllMetadata);
 
             var newPath = GetRebasedPath();
             if (!string.Equals(Path, newPath, StringComparison.Ordinal))