Merge branch 'master' into authenticationdb-efcore

# Conflicts:
#	Jellyfin.Api/Helpers/RequestHelpers.cs

49 files changed, 254 insertions, 157 deletions

diff --git a/MediaBrowser.Controller/Entities/AggregateFolder.cs b/MediaBrowser.Controller/Entities/AggregateFolder.cs
index 6ebea5f449..e365bfda1f 100644
--- a/MediaBrowser.Controller/Entities/AggregateFolder.cs
+++ b/MediaBrowser.Controller/Entities/AggregateFolder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -84,6 +86,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         private bool _requiresRefresh;
+
         public override bool RequiresRefresh()
         {
             var changed = base.RequiresRefresh() || _requiresRefresh;
@@ -120,8 +123,7 @@ namespace MediaBrowser.Controller.Entities
 
             var args = new ItemResolveArgs(ConfigurationManager.ApplicationPaths, directoryService)
             {
-                FileInfo = FileSystem.GetDirectoryInfo(path),
-                Path = path
+                FileInfo = FileSystem.GetDirectoryInfo(path)
             };
 
             // Gather child folder and files
diff --git a/MediaBrowser.Controller/Entities/Audio/Audio.cs b/MediaBrowser.Controller/Entities/Audio/Audio.cs
index 8220464b39..4c2b7cb7c7 100644
--- a/MediaBrowser.Controller/Entities/Audio/Audio.cs
+++ b/MediaBrowser.Controller/Entities/Audio/Audio.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Audio/IHasAlbumArtist.cs b/MediaBrowser.Controller/Entities/Audio/IHasAlbumArtist.cs
index 20fad4cb0e..1625c748a8 100644
--- a/MediaBrowser.Controller/Entities/Audio/IHasAlbumArtist.cs
+++ b/MediaBrowser.Controller/Entities/Audio/IHasAlbumArtist.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Collections.Generic;
diff --git a/MediaBrowser.Controller/Entities/Audio/IHasMusicGenres.cs b/MediaBrowser.Controller/Entities/Audio/IHasMusicGenres.cs
index ac4dd1688b..db60c3071d 100644
--- a/MediaBrowser.Controller/Entities/Audio/IHasMusicGenres.cs
+++ b/MediaBrowser.Controller/Entities/Audio/IHasMusicGenres.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 namespace MediaBrowser.Controller.Entities.Audio
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs b/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
index 9a33ad9d74..610bce4f5f 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicAlbum.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
index 8a9bb12c7b..b07c3eed13 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicArtist.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -112,7 +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>
diff --git a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
index f0c076108e..b07d47ffdd 100644
--- a/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
+++ b/MediaBrowser.Controller/Entities/Audio/MusicGenre.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/AudioBook.cs b/MediaBrowser.Controller/Entities/AudioBook.cs
index f4bd851e1b..4052846228 100644
--- a/MediaBrowser.Controller/Entities/AudioBook.cs
+++ b/MediaBrowser.Controller/Entities/AudioBook.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index 53d45261e6..238c98982c 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -106,15 +108,10 @@ namespace MediaBrowser.Controller.Entities
         {
             get
             {
-                if (_themeSongIds == null)
-                {
-                    _themeSongIds = GetExtras()
-                        .Where(extra => extra.ExtraType == Model.Entities.ExtraType.ThemeSong)
-                        .Select(song => song.Id)
-                        .ToArray();
-                }
-
-                return _themeSongIds;
+                return _themeSongIds ??= GetExtras()
+                    .Where(extra => extra.ExtraType == Model.Entities.ExtraType.ThemeSong)
+                    .Select(song => song.Id)
+                    .ToArray();
             }
 
             private set
@@ -128,15 +125,10 @@ namespace MediaBrowser.Controller.Entities
         {
             get
             {
-                if (_themeVideoIds == null)
-                {
-                    _themeVideoIds = GetExtras()
-                        .Where(extra => extra.ExtraType == Model.Entities.ExtraType.ThemeVideo)
-                        .Select(song => song.Id)
-                        .ToArray();
-                }
-
-                return _themeVideoIds;
+                return _themeVideoIds ??= GetExtras()
+                    .Where(extra => extra.ExtraType == Model.Entities.ExtraType.ThemeVideo)
+                    .Select(song => song.Id)
+                    .ToArray();
             }
 
             private set
@@ -347,9 +339,9 @@ namespace MediaBrowser.Controller.Entities
             get
             {
                 // if (IsOffline)
-                //{
+                // {
                 //    return LocationType.Offline;
-                //}
+                // }
 
                 var path = Path;
                 if (string.IsNullOrEmpty(path))
@@ -2324,7 +2316,7 @@ namespace MediaBrowser.Controller.Entities
                 .Where(i => i.IsLocalFile)
                 .Select(i => System.IO.Path.GetDirectoryName(i.Path))
                 .Distinct(StringComparer.OrdinalIgnoreCase)
-                .SelectMany(i => directoryService.GetFilePaths(i))
+                .SelectMany(directoryService.GetFilePaths)
                 .ToList();
 
             var deletedImages = ImageInfos
@@ -2777,11 +2769,11 @@ 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)
             {
diff --git a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
index c65477d39a..c39b18891f 100644
--- a/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
+++ b/MediaBrowser.Controller/Entities/BaseItemExtensions.cs
@@ -1,5 +1,9 @@
+#nullable disable
+
+#nullable enable
 #pragma warning disable CS1591
 
+using System;
 using System.Linq;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.IO;
@@ -64,9 +68,19 @@ namespace MediaBrowser.Controller.Entities
         /// <param name="source">The source object.</param>
         /// <param name="dest">The destination object.</param>
         public static void DeepCopy<T, TU>(this T source, TU dest)
-        where T : BaseItem
-        where TU : BaseItem
+            where T : BaseItem
+            where TU : BaseItem
         {
+            if (source == null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
+            if (dest == null)
+            {
+                throw new ArgumentNullException(nameof(dest));
+            }
+
             var destProps = typeof(TU).GetProperties().Where(x => x.CanWrite).ToList();
 
             foreach (var sourceProp in typeof(T).GetProperties())
@@ -99,8 +113,8 @@ namespace MediaBrowser.Controller.Entities
         /// </summary>
         /// <param name="source">The source object.</param>
         public static TU DeepCopy<T, TU>(this T source)
-        where T : BaseItem
-        where TU : BaseItem, new()
+            where T : BaseItem
+            where TU : BaseItem, new()
         {
             var dest = new TU();
             source.DeepCopy(dest);
diff --git a/MediaBrowser.Controller/Entities/BasePluginFolder.cs b/MediaBrowser.Controller/Entities/BasePluginFolder.cs
index ef5a5a734c..1bd25042f2 100644
--- a/MediaBrowser.Controller/Entities/BasePluginFolder.cs
+++ b/MediaBrowser.Controller/Entities/BasePluginFolder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Text.Json.Serialization;
diff --git a/MediaBrowser.Controller/Entities/Book.cs b/MediaBrowser.Controller/Entities/Book.cs
index 55945283c9..d75beb06da 100644
--- a/MediaBrowser.Controller/Entities/Book.cs
+++ b/MediaBrowser.Controller/Entities/Book.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -10,6 +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;
 
@@ -26,11 +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 76b6d39a93..a86da29ce4 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -61,7 +63,6 @@ namespace MediaBrowser.Controller.Entities
             try
             {
                 var result = XmlSerializer.DeserializeFromFile(typeof(LibraryOptions), GetLibraryOptionsPath(path)) as LibraryOptions;
-
                 if (result == null)
                 {
                     return new LibraryOptions();
@@ -271,7 +272,6 @@ namespace MediaBrowser.Controller.Entities
             var args = new ItemResolveArgs(ConfigurationManager.ApplicationPaths, directoryService)
             {
                 FileInfo = FileSystem.GetDirectoryInfo(path),
-                Path = path,
                 Parent = GetParent() as Folder,
                 CollectionType = CollectionType
             };
@@ -355,9 +355,7 @@ namespace MediaBrowser.Controller.Entities
 
             if (result.Count == 0)
             {
-                var folder = LibraryManager.FindByPath(path, true) as Folder;
-
-                if (folder != null)
+                if (LibraryManager.FindByPath(path, true) is Folder folder)
                 {
                     result.Add(folder);
                 }
diff --git a/MediaBrowser.Controller/Entities/Extensions.cs b/MediaBrowser.Controller/Entities/Extensions.cs
index 3a34c668cf..244cc00bea 100644
--- a/MediaBrowser.Controller/Entities/Extensions.cs
+++ b/MediaBrowser.Controller/Entities/Extensions.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 using System;
 using System.Linq;
 using MediaBrowser.Common.Extensions;
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index cac5026f70..a59f5c6e4b 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -1,8 +1,9 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text.Json.Serialization;
@@ -1434,9 +1435,14 @@ namespace MediaBrowser.Controller.Entities
             var linkedChildren = LinkedChildren;
             foreach (var i in linkedChildren)
             {
-                if (i.ItemId.HasValue && i.ItemId.Value == itemId)
+                if (i.ItemId.HasValue)
                 {
-                    return true;
+                    if (i.ItemId.Value == itemId)
+                    {
+                        return true;
+                    }
+
+                    continue;
                 }
 
                 var child = GetLinkedChild(i);
@@ -1764,20 +1770,15 @@ namespace MediaBrowser.Controller.Entities
                     {
                         EnableImages = false
                     }
-                });
-
-                double unplayedCount = unplayedQueryResult.TotalRecordCount;
+                }).TotalRecordCount;
 
-                dto.UnplayedItemCount = unplayedQueryResult.TotalRecordCount;
+                dto.UnplayedItemCount = unplayedQueryResult;
 
-                if (itemDto != null && itemDto.RecursiveItemCount.HasValue)
+                if (itemDto?.RecursiveItemCount > 0)
                 {
-                    if (itemDto.RecursiveItemCount.Value > 0)
-                    {
-                        var unplayedPercentage = (unplayedCount / itemDto.RecursiveItemCount.Value) * 100;
-                        dto.PlayedPercentage = 100 - unplayedPercentage;
-                        dto.Played = dto.PlayedPercentage.Value >= 100;
-                    }
+                    var unplayedPercentage = ((double)unplayedQueryResult / itemDto.RecursiveItemCount.Value) * 100;
+                    dto.PlayedPercentage = 100 - unplayedPercentage;
+                    dto.Played = dto.PlayedPercentage.Value >= 100;
                 }
                 else
                 {
diff --git a/MediaBrowser.Controller/Entities/Genre.cs b/MediaBrowser.Controller/Entities/Genre.cs
index 74a1702040..310c0c9ec7 100644
--- a/MediaBrowser.Controller/Entities/Genre.cs
+++ b/MediaBrowser.Controller/Entities/Genre.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -33,7 +35,7 @@ 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>
diff --git a/MediaBrowser.Controller/Entities/ICollectionFolder.cs b/MediaBrowser.Controller/Entities/ICollectionFolder.cs
index b84a9fa6f1..2304570fd7 100644
--- a/MediaBrowser.Controller/Entities/ICollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/ICollectionFolder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/IHasAspectRatio.cs b/MediaBrowser.Controller/Entities/IHasAspectRatio.cs
index d7d0076681..3aeb7468f2 100644
--- a/MediaBrowser.Controller/Entities/IHasAspectRatio.cs
+++ b/MediaBrowser.Controller/Entities/IHasAspectRatio.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace MediaBrowser.Controller.Entities
 {
     /// <summary>
diff --git a/MediaBrowser.Controller/Entities/IHasDisplayOrder.cs b/MediaBrowser.Controller/Entities/IHasDisplayOrder.cs
index 13226b2346..14459624e9 100644
--- a/MediaBrowser.Controller/Entities/IHasDisplayOrder.cs
+++ b/MediaBrowser.Controller/Entities/IHasDisplayOrder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace MediaBrowser.Controller.Entities
 {
     /// <summary>
diff --git a/MediaBrowser.Controller/Entities/IHasMediaSources.cs b/MediaBrowser.Controller/Entities/IHasMediaSources.cs
index 0f612262a8..98c3b3edf6 100644
--- a/MediaBrowser.Controller/Entities/IHasMediaSources.cs
+++ b/MediaBrowser.Controller/Entities/IHasMediaSources.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/IHasProgramAttributes.cs b/MediaBrowser.Controller/Entities/IHasProgramAttributes.cs
index f747b5149a..f80f7c304c 100644
--- a/MediaBrowser.Controller/Entities/IHasProgramAttributes.cs
+++ b/MediaBrowser.Controller/Entities/IHasProgramAttributes.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using MediaBrowser.Model.LiveTv;
diff --git a/MediaBrowser.Controller/Entities/IHasSeries.cs b/MediaBrowser.Controller/Entities/IHasSeries.cs
index 5444f1f523..64d769d5ba 100644
--- a/MediaBrowser.Controller/Entities/IHasSeries.cs
+++ b/MediaBrowser.Controller/Entities/IHasSeries.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/IHasSpecialFeatures.cs b/MediaBrowser.Controller/Entities/IHasSpecialFeatures.cs
index 6a350212b1..f317a02ff3 100644
--- a/MediaBrowser.Controller/Entities/IHasSpecialFeatures.cs
+++ b/MediaBrowser.Controller/Entities/IHasSpecialFeatures.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/IHasTrailers.cs b/MediaBrowser.Controller/Entities/IHasTrailers.cs
index d1f6f2b7e2..2bd9ded337 100644
--- a/MediaBrowser.Controller/Entities/IHasTrailers.cs
+++ b/MediaBrowser.Controller/Entities/IHasTrailers.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
index 270217356f..c060210296 100644
--- a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
index 5b96a5af65..3e1d892748 100644
--- a/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalPeopleQuery.cs
@@ -1,12 +1,26 @@
+#nullable disable
+
 #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>
@@ -14,9 +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; }
 
@@ -27,11 +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/ItemImageInfo.cs b/MediaBrowser.Controller/Entities/ItemImageInfo.cs
index 570d8eec0c..ea8555dbfe 100644
--- a/MediaBrowser.Controller/Entities/ItemImageInfo.cs
+++ b/MediaBrowser.Controller/Entities/ItemImageInfo.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/LinkedChild.cs b/MediaBrowser.Controller/Entities/LinkedChild.cs
index 8e0f721e77..fd5fef3dc5 100644
--- a/MediaBrowser.Controller/Entities/LinkedChild.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChild.cs
@@ -1,15 +1,20 @@
+#nullable disable
+
 #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; }
@@ -20,7 +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; }
 
@@ -39,41 +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 0000000000..66fc44b8a9
--- /dev/null
+++ b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
@@ -0,0 +1,34 @@
+#nullable disable
+
+#pragma warning disable CS1591
+
+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();
+        }
+    }
+}
\ 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 0000000000..9ddb7b6202
--- /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/BoxSet.cs b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
index 05e4229cad..74e84288d1 100644
--- a/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
+++ b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -217,8 +219,7 @@ namespace MediaBrowser.Controller.Entities.Movies
 
         private IEnumerable<BaseItem> FlattenItems(BaseItem item, List<Guid> expandedFolders)
         {
-            var boxset = item as BoxSet;
-            if (boxset != null)
+            if (item is BoxSet boxset)
             {
                 if (!expandedFolders.Contains(item.Id))
                 {
diff --git a/MediaBrowser.Controller/Entities/Movies/Movie.cs b/MediaBrowser.Controller/Entities/Movies/Movie.cs
index 8b67aaccc6..64d60c2e90 100644
--- a/MediaBrowser.Controller/Entities/Movies/Movie.cs
+++ b/MediaBrowser.Controller/Entities/Movies/Movie.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/MusicVideo.cs b/MediaBrowser.Controller/Entities/MusicVideo.cs
index b278a01423..4e622ba01b 100644
--- a/MediaBrowser.Controller/Entities/MusicVideo.cs
+++ b/MediaBrowser.Controller/Entities/MusicVideo.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -11,15 +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;
diff --git a/MediaBrowser.Controller/Entities/PeopleHelper.cs b/MediaBrowser.Controller/Entities/PeopleHelper.cs
index 1f3758a73a..687ce1ec8d 100644
--- a/MediaBrowser.Controller/Entities/PeopleHelper.cs
+++ b/MediaBrowser.Controller/Entities/PeopleHelper.cs
@@ -100,23 +100,5 @@ namespace MediaBrowser.Controller.Entities
                 existing.SetProviderId(id.Key, id.Value);
             }
         }
-
-        public static bool ContainsPerson(List<PersonInfo> people, string name)
-        {
-            if (string.IsNullOrEmpty(name))
-            {
-                throw new ArgumentNullException(nameof(name));
-            }
-
-            foreach (var i in people)
-            {
-                if (string.Equals(i.Name, name, StringComparison.OrdinalIgnoreCase))
-                {
-                    return true;
-                }
-            }
-
-            return false;
-        }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/Person.cs b/MediaBrowser.Controller/Entities/Person.cs
index c4fcb0267a..d9ff55362c 100644
--- a/MediaBrowser.Controller/Entities/Person.cs
+++ b/MediaBrowser.Controller/Entities/Person.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/PersonInfo.cs b/MediaBrowser.Controller/Entities/PersonInfo.cs
index 4ff9b0955c..fb79323f8f 100644
--- a/MediaBrowser.Controller/Entities/PersonInfo.cs
+++ b/MediaBrowser.Controller/Entities/PersonInfo.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Photo.cs b/MediaBrowser.Controller/Entities/Photo.cs
index 2fc66176f6..3312a0e3e2 100644
--- a/MediaBrowser.Controller/Entities/Photo.cs
+++ b/MediaBrowser.Controller/Entities/Photo.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System.Text.Json.Serialization;
@@ -24,8 +26,7 @@ namespace MediaBrowser.Controller.Entities
                 var parents = GetParents();
                 foreach (var parent in parents)
                 {
-                    var photoAlbum = parent as PhotoAlbum;
-                    if (photoAlbum != null)
+                    if (parent is PhotoAlbum photoAlbum)
                     {
                         return photoAlbum;
                     }
diff --git a/MediaBrowser.Controller/Entities/Share.cs b/MediaBrowser.Controller/Entities/Share.cs
index 50f1655f39..7e4ec18307 100644
--- a/MediaBrowser.Controller/Entities/Share.cs
+++ b/MediaBrowser.Controller/Entities/Share.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 namespace MediaBrowser.Controller.Entities
diff --git a/MediaBrowser.Controller/Entities/Studio.cs b/MediaBrowser.Controller/Entities/Studio.cs
index 9018ddb75e..ae1d10447b 100644
--- a/MediaBrowser.Controller/Entities/Studio.cs
+++ b/MediaBrowser.Controller/Entities/Studio.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/TV/Episode.cs b/MediaBrowser.Controller/Entities/TV/Episode.cs
index dc12fbbead..2724bd9b3d 100644
--- a/MediaBrowser.Controller/Entities/TV/Episode.cs
+++ b/MediaBrowser.Controller/Entities/TV/Episode.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -99,7 +101,15 @@ namespace MediaBrowser.Controller.Entities.TV
                     take--;
                 }
 
-                list.InsertRange(0, seriesUserDataKeys.Take(take).Select(i => i + ParentIndexNumber.Value.ToString("000") + IndexNumber.Value.ToString("000")));
+                var newList = seriesUserDataKeys.GetRange(0, take);
+                var suffix = ParentIndexNumber.Value.ToString("000", CultureInfo.InvariantCulture) + IndexNumber.Value.ToString("000", CultureInfo.InvariantCulture);
+                for (int i = 0; i < take; i++)
+                {
+                    newList[i] = newList[i] + suffix;
+                }
+
+                newList.AddRange(list);
+                list = newList;
             }
 
             return list;
diff --git a/MediaBrowser.Controller/Entities/TV/Season.cs b/MediaBrowser.Controller/Entities/TV/Season.cs
index 93bdd6e706..ad3e0fe8d6 100644
--- a/MediaBrowser.Controller/Entities/TV/Season.cs
+++ b/MediaBrowser.Controller/Entities/TV/Season.cs
@@ -1,7 +1,10 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text.Json.Serialization;
 using Jellyfin.Data.Entities;
@@ -56,7 +59,15 @@ namespace MediaBrowser.Controller.Entities.TV
             var series = Series;
             if (series != null)
             {
-                list.InsertRange(0, series.GetUserDataKeys().Select(i => i + (IndexNumber ?? 0).ToString("000")));
+                var newList = series.GetUserDataKeys();
+                var suffix = (IndexNumber ?? 0).ToString("000", CultureInfo.InvariantCulture);
+                for (int i = 0; i < newList.Count; i++)
+                {
+                    newList[i] = newList[i] + suffix;
+                }
+
+                newList.AddRange(list);
+                list = newList;
             }
 
             return list;
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index a410c1b66f..ded825abc0 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -169,14 +171,12 @@ namespace MediaBrowser.Controller.Entities.TV
         {
             var list = base.GetUserDataKeys();
 
-            var key = this.GetProviderId(MetadataProvider.Imdb);
-            if (!string.IsNullOrEmpty(key))
+            if (this.TryGetProviderId(MetadataProvider.Imdb, out var key))
             {
                 list.Insert(0, key);
             }
 
-            key = this.GetProviderId(MetadataProvider.Tvdb);
-            if (!string.IsNullOrEmpty(key))
+            if (this.TryGetProviderId(MetadataProvider.Tvdb, out key))
             {
                 list.Insert(0, key);
             }
@@ -208,7 +208,7 @@ namespace MediaBrowser.Controller.Entities.TV
             query.AncestorWithPresentationUniqueKey = null;
             query.SeriesPresentationUniqueKey = seriesKey;
             query.IncludeItemTypes = new[] { nameof(Season) };
-            query.OrderBy = new[] { ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Ascending)).ToArray();
+            query.OrderBy = new[] { (ItemSortBy.SortName, SortOrder.Ascending) };
 
             if (user != null && !user.DisplayMissingEpisodes)
             {
@@ -228,7 +228,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 query.SeriesPresentationUniqueKey = seriesKey;
                 if (query.OrderBy.Count == 0)
                 {
-                    query.OrderBy = new[] { ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Ascending)).ToArray();
+                    query.OrderBy = new[] { (ItemSortBy.SortName, SortOrder.Ascending) };
                 }
 
                 if (query.IncludeItemTypes.Length == 0)
@@ -254,7 +254,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 AncestorWithPresentationUniqueKey = null,
                 SeriesPresentationUniqueKey = seriesKey,
                 IncludeItemTypes = new[] { nameof(Episode), nameof(Season) },
-                OrderBy = new[] { ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Ascending)).ToArray(),
+                OrderBy = new[] { (ItemSortBy.SortName, SortOrder.Ascending) },
                 DtoOptions = options
             };
 
@@ -318,20 +318,13 @@ namespace MediaBrowser.Controller.Entities.TV
 
                 cancellationToken.ThrowIfCancellationRequested();
 
-                var skipItem = false;
-
-                var episode = item as Episode;
-
-                if (episode != null
+                bool skipItem = item is Episode episode
                     && refreshOptions.MetadataRefreshMode != MetadataRefreshMode.FullRefresh
                     && !refreshOptions.ReplaceAllMetadata
                     && episode.IsMissingEpisode
                     && episode.LocationType == LocationType.Virtual
                     && episode.PremiereDate.HasValue
-                    && (DateTime.UtcNow - episode.PremiereDate.Value).TotalDays > 30)
-                {
-                    skipItem = true;
-                }
+                    && (DateTime.UtcNow - episode.PremiereDate.Value).TotalDays > 30;
 
                 if (!skipItem)
                 {
@@ -365,7 +358,7 @@ namespace MediaBrowser.Controller.Entities.TV
                 AncestorWithPresentationUniqueKey = queryFromSeries ? null : seriesKey,
                 SeriesPresentationUniqueKey = queryFromSeries ? seriesKey : null,
                 IncludeItemTypes = new[] { nameof(Episode) },
-                OrderBy = new[] { ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Ascending)).ToArray(),
+                OrderBy = new[] { (ItemSortBy.SortName, SortOrder.Ascending) },
                 DtoOptions = options
             };
             if (user != null)
diff --git a/MediaBrowser.Controller/Entities/Trailer.cs b/MediaBrowser.Controller/Entities/Trailer.cs
index 9ae8ad7087..b086b5906b 100644
--- a/MediaBrowser.Controller/Entities/Trailer.cs
+++ b/MediaBrowser.Controller/Entities/Trailer.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/UserItemData.cs b/MediaBrowser.Controller/Entities/UserItemData.cs
index db63c42e4c..f60359c014 100644
--- a/MediaBrowser.Controller/Entities/UserItemData.cs
+++ b/MediaBrowser.Controller/Entities/UserItemData.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/UserRootFolder.cs b/MediaBrowser.Controller/Entities/UserRootFolder.cs
index 7f7224ae07..e492740ed0 100644
--- a/MediaBrowser.Controller/Entities/UserRootFolder.cs
+++ b/MediaBrowser.Controller/Entities/UserRootFolder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/UserView.cs b/MediaBrowser.Controller/Entities/UserView.cs
index b1da4d64cb..0dfde27667 100644
--- a/MediaBrowser.Controller/Entities/UserView.cs
+++ b/MediaBrowser.Controller/Entities/UserView.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -75,10 +77,7 @@ namespace MediaBrowser.Controller.Entities
 
         public override List<BaseItem> GetChildren(User user, bool includeLinkedChildren, InternalItemsQuery query)
         {
-            if (query == null)
-            {
-                query = new InternalItemsQuery(user);
-            }
+            query ??= new InternalItemsQuery(user);
 
             query.EnableTotalRecordCount = false;
             var result = GetItemList(query);
diff --git a/MediaBrowser.Controller/Entities/UserViewBuilder.cs b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
index 4e33a6bbde..15a4573c2e 100644
--- a/MediaBrowser.Controller/Entities/UserViewBuilder.cs
+++ b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
@@ -217,8 +219,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetMovieLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { ItemSortBy.DateCreated, ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Descending)).ToArray();
-
+            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
@@ -230,7 +231,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetMovieResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { ItemSortBy.DatePlayed, ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Descending)).ToArray();
+            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
@@ -327,8 +328,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { ItemSortBy.DateCreated, ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Descending)).ToArray();
-
+            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
@@ -356,7 +356,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { ItemSortBy.DatePlayed, ItemSortBy.SortName }.Select(i => new ValueTuple<string, SortOrder>(i, SortOrder.Descending)).ToArray();
+            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index 6320b01b87..723027a883 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;
diff --git a/MediaBrowser.Controller/Entities/Year.cs b/MediaBrowser.Controller/Entities/Year.cs
index b2e4d307a6..4d84a151a7 100644
--- a/MediaBrowser.Controller/Entities/Year.cs
+++ b/MediaBrowser.Controller/Entities/Year.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 #pragma warning disable CS1591
 
 using System;