Complete LinkedChildren integration and batch DTO optimizations

This commit integrates remaining performance changes:

- Add batch user data fetching in DtoService to reduce N+1 queries
- Add GetNextUpEpisodesBatch in TVSeriesManager for efficient batch retrieval
- Update Video/Movie/BoxSet to use LibraryManager for alternate versions
- Transition LinkedChild to use ItemId instead of Path (obsolete Path/LibraryItemId)
- Update providers and controllers for LinkedChildren-based references
- Add NextUpEpisodeBatchResult for batched episode queries
- Integrate IDescendantQueryProvider in SqliteDatabaseProvider

17 files changed, 397 insertions, 409 deletions

diff --git a/MediaBrowser.Controller/Dto/IDtoService.cs b/MediaBrowser.Controller/Dto/IDtoService.cs
index f1d507fcbd..8dc6f0aa68 100644
--- a/MediaBrowser.Controller/Dto/IDtoService.cs
+++ b/MediaBrowser.Controller/Dto/IDtoService.cs
@@ -36,8 +36,9 @@ namespace MediaBrowser.Controller.Dto
         /// <param name="options">The options.</param>
         /// <param name="user">The user.</param>
         /// <param name="owner">The owner.</param>
+        /// <param name="skipVisibilityCheck">Skip redundant visibility check if items are already filtered.</param>
         /// <returns>The <see cref="IReadOnlyList{T}"/> of <see cref="BaseItemDto"/>.</returns>
-        IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null);
+        IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null, bool skipVisibilityCheck = false);
 
         /// <summary>
         /// Gets the item by name dto.
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index eb7daeb532..13af7a6178 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -1806,10 +1806,23 @@ namespace MediaBrowser.Controller.Entities
             return item;
         }
 
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for legacy LinkedChild data
         private BaseItem FindLinkedChild(LinkedChild info)
         {
-            var path = info.Path;
+            // First try to find by ItemId (new preferred method)
+            if (info.ItemId.HasValue && !info.ItemId.Value.Equals(Guid.Empty))
+            {
+                var item = LibraryManager.GetItemById(info.ItemId.Value);
+                if (item is not null)
+                {
+                    return item;
+                }
 
+                Logger.LogWarning("Unable to find linked item by ItemId {0}", info.ItemId);
+            }
+
+            // Fall back to Path (legacy method)
+            var path = info.Path;
             if (!string.IsNullOrEmpty(path))
             {
                 path = FileSystem.MakeAbsolutePath(ContainingFolderPath, path);
@@ -1824,13 +1837,14 @@ namespace MediaBrowser.Controller.Entities
                 return itemByPath;
             }
 
+            // Fall back to LibraryItemId (legacy method)
             if (!string.IsNullOrEmpty(info.LibraryItemId))
             {
                 var item = LibraryManager.GetItemById(info.LibraryItemId);
 
                 if (item is null)
                 {
-                    Logger.LogWarning("Unable to find linked item at path {0}", info.Path);
+                    Logger.LogWarning("Unable to find linked item by LibraryItemId {0}", info.LibraryItemId);
                 }
 
                 return item;
@@ -1838,6 +1852,7 @@ namespace MediaBrowser.Controller.Entities
 
             return null;
         }
+#pragma warning restore CS0618
 
         /// <summary>
         /// Adds a studio to the item.
diff --git a/MediaBrowser.Controller/Entities/CollectionFolder.cs b/MediaBrowser.Controller/Entities/CollectionFolder.cs
index ca79e62454..cf615788ee 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -45,6 +45,11 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
+        /// Event raised when library options are updated for any collection folder.
+        /// </summary>
+        public static event EventHandler<LibraryOptionsUpdatedEventArgs> LibraryOptionsUpdated;
+
+        /// <summary>
         /// Gets the display preferences id.
         /// </summary>
         /// <remarks>
@@ -168,6 +173,8 @@ namespace MediaBrowser.Controller.Entities
             }
 
             XmlSerializer.SerializeToFile(clone, GetLibraryOptionsPath(path));
+
+            LibraryOptionsUpdated?.Invoke(null, new LibraryOptionsUpdatedEventArgs(path, options));
         }
 
         public static void OnCollectionFolderChange()
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index d2a3290c47..6338e54292 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -59,6 +59,10 @@ namespace MediaBrowser.Controller.Entities
         /// <value><c>true</c> if this instance is root; otherwise, <c>false</c>.</value>
         public bool IsRoot { get; set; }
 
+        /// <summary>
+        /// Gets or sets the linked children.
+        /// </summary>
+        [JsonIgnore]
         public LinkedChild[] LinkedChildren { get; set; }
 
         [JsonIgnore]
@@ -455,6 +459,14 @@ namespace MediaBrowser.Controller.Entities
                 // If it's an AggregateFolder, don't remove
                 if (shouldRemove && itemsRemoved.Count > 0)
                 {
+                    // Build a set of paths that are alternate versions of valid children
+                    // These items should not be deleted - they're managed by their primary video
+                    var alternateVersionPaths = validChildren
+                        .OfType<Video>()
+                        .SelectMany(v => v.LocalAlternateVersions ?? [])
+                        .Where(p => !string.IsNullOrEmpty(p))
+                        .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
                     foreach (var item in itemsRemoved)
                     {
                         if (!item.CanDelete())
@@ -463,6 +475,24 @@ namespace MediaBrowser.Controller.Entities
                             continue;
                         }
 
+                        // Skip items that are alternate versions of another video
+                        if (item is Video video)
+                        {
+                            // Check via PrimaryVersionId
+                            if (!string.IsNullOrEmpty(video.PrimaryVersionId))
+                            {
+                                Logger.LogDebug("Item is an alternate version (via PrimaryVersionId), skipping deletion: {Path}", item.Path ?? item.Name);
+                                continue;
+                            }
+
+                            // Check if path is in LocalAlternateVersions of any valid child
+                            if (!string.IsNullOrEmpty(item.Path) && alternateVersionPaths.Contains(item.Path))
+                            {
+                                Logger.LogDebug("Item path matches an alternate version, skipping deletion: {Path}", item.Path);
+                                continue;
+                            }
+                        }
+
                         if (item.IsFileProtocol)
                         {
                             Logger.LogDebug("Removed item: {Path}", item.Path);
@@ -806,104 +836,12 @@ namespace MediaBrowser.Controller.Entities
 
         private bool RequiresPostFiltering(InternalItemsQuery query)
         {
-            if (LinkedChildren.Length > 0)
-            {
-                if (this is not ICollectionFolder)
-                {
-                    Logger.LogDebug("{Type}: Query requires post-filtering due to LinkedChildren.", GetType().Name);
-                    return true;
-                }
-            }
-
-            // Filter by Video3DFormat
-            if (query.Is3D.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to Is3D");
-                return true;
-            }
-
-            if (query.HasOfficialRating.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasOfficialRating");
-                return true;
-            }
-
-            if (query.IsPlaceHolder.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to IsPlaceHolder");
-                return true;
-            }
-
-            if (query.HasSpecialFeature.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasSpecialFeature");
-                return true;
-            }
-
-            if (query.HasSubtitles.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasSubtitles");
-                return true;
-            }
-
-            if (query.HasTrailer.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasTrailer");
-                return true;
-            }
-
-            if (query.HasThemeSong.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasThemeSong");
-                return true;
-            }
-
-            if (query.HasThemeVideo.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasThemeVideo");
-                return true;
-            }
-
-            // Filter by VideoType
-            if (query.VideoTypes.Length > 0)
-            {
-                Logger.LogDebug("Query requires post-filtering due to VideoTypes");
-                return true;
-            }
-
             if (CollapseBoxSetItems(query, this, query.User, ConfigurationManager))
             {
                 Logger.LogDebug("Query requires post-filtering due to CollapseBoxSetItems");
                 return true;
             }
 
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                Logger.LogDebug("Query requires post-filtering due to AdjacentTo");
-                return true;
-            }
-
-            if (query.SeriesStatuses.Length > 0)
-            {
-                Logger.LogDebug("Query requires post-filtering due to SeriesStatuses");
-                return true;
-            }
-
-            if (query.AiredDuringSeason.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to AiredDuringSeason");
-                return true;
-            }
-
-            if (query.IsPlayed.HasValue)
-            {
-                if (query.IncludeItemTypes.Length == 1 && query.IncludeItemTypes.Contains(BaseItemKind.Series))
-                {
-                    Logger.LogDebug("Query requires post-filtering due to IsPlayed");
-                    return true;
-                }
-            }
-
             return false;
         }
 
@@ -1012,29 +950,6 @@ namespace MediaBrowser.Controller.Entities
                 items = CollapseBoxSetItemsIfNeeded(items, query, this, user, ConfigurationManager, CollectionManager);
             }
 
-#pragma warning disable CA1309
-            if (!string.IsNullOrEmpty(query.NameStartsWithOrGreater))
-            {
-                items = items.Where(i => string.Compare(query.NameStartsWithOrGreater, i.SortName, StringComparison.InvariantCultureIgnoreCase) < 1);
-            }
-
-            if (!string.IsNullOrEmpty(query.NameStartsWith))
-            {
-                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.InvariantCultureIgnoreCase));
-            }
-
-            if (!string.IsNullOrEmpty(query.NameLessThan))
-            {
-                items = items.Where(i => string.Compare(query.NameLessThan, i.SortName, StringComparison.InvariantCultureIgnoreCase) == 1);
-            }
-#pragma warning restore CA1309
-
-            // This must be the last filter
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                items = UserViewBuilder.FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
-            }
-
             var filteredItems = items as IReadOnlyList<BaseItem> ?? items.ToList();
             var result = UserViewBuilder.SortAndPage(filteredItems, null, query, LibraryManager);
 
@@ -1664,11 +1579,13 @@ namespace MediaBrowser.Controller.Entities
 
                             if (!string.IsNullOrEmpty(resolvedPath))
                             {
+#pragma warning disable CS0618 // Type or member is obsolete - shortcuts require Path for lazy ItemId resolution
                                 return new LinkedChild
                                 {
                                     Path = resolvedPath,
                                     Type = LinkedChildType.Shortcut
                                 };
+#pragma warning restore CS0618
                             }
 
                             Logger.LogError("Error resolving shortcut {0}", i.FullName);
@@ -1786,38 +1703,42 @@ namespace MediaBrowser.Controller.Entities
                 return;
             }
 
-            if (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount))
-            {
-                itemDto.RecursiveItemCount = GetRecursiveChildCount(user);
-            }
-
-            if (SupportsPlayedStatus)
+            if (SupportsPlayedStatus || (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount)))
             {
-                var unplayedQueryResult = GetItems(new InternalItemsQuery(user)
-                {
-                    Recursive = true,
-                    IsFolder = false,
-                    IsVirtualItem = false,
-                    EnableTotalRecordCount = true,
-                    Limit = 0,
-                    IsPlayed = false,
-                    DtoOptions = new DtoOptions(false)
-                    {
-                        EnableImages = false
-                    }
-                }).TotalRecordCount;
+                var query = new InternalItemsQuery(user);
+                LibraryManager.ConfigureUserAccess(query, user);
 
-                dto.UnplayedItemCount = unplayedQueryResult;
+                int playedCount;
+                int totalCount;
 
-                if (itemDto?.RecursiveItemCount > 0)
+                if (LinkedChildren.Length > 0)
                 {
-                    var unplayedPercentage = ((double)unplayedQueryResult / itemDto.RecursiveItemCount.Value) * 100;
-                    dto.PlayedPercentage = 100 - unplayedPercentage;
-                    dto.Played = dto.PlayedPercentage.Value >= 100;
+                    (playedCount, totalCount) = ItemRepository.GetPlayedAndTotalCountFromLinkedChildren(query, Id);
                 }
                 else
                 {
-                    dto.Played = (dto.UnplayedItemCount ?? 0) == 0;
+                    (playedCount, totalCount) = ItemRepository.GetPlayedAndTotalCount(query, Id);
+                }
+
+                if (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount))
+                {
+                    itemDto.RecursiveItemCount = totalCount;
+                }
+
+                if (SupportsPlayedStatus)
+                {
+                    var unplayedCount = totalCount - playedCount;
+                    dto.UnplayedItemCount = unplayedCount;
+
+                    if (totalCount > 0)
+                    {
+                        dto.PlayedPercentage = playedCount / (double)totalCount * 100;
+                        dto.Played = playedCount >= totalCount;
+                    }
+                    else
+                    {
+                        dto.Played = true;
+                    }
                 }
             }
         }
diff --git a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
index 24fe3bb32d..b36ea627d8 100644
--- a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
@@ -33,6 +33,7 @@ namespace MediaBrowser.Controller.Entities
             ExcludeItemIds = Array.Empty<Guid>();
             ExcludeItemTypes = Array.Empty<BaseItemKind>();
             ExcludeTags = Array.Empty<string>();
+            ExtraTypes = Array.Empty<ExtraType>();
             GenreIds = Array.Empty<Guid>();
             Genres = Array.Empty<string>();
             GroupByPresentationUniqueKey = true;
@@ -44,6 +45,7 @@ namespace MediaBrowser.Controller.Entities
             MediaTypes = Array.Empty<MediaType>();
             OfficialRatings = Array.Empty<string>();
             OrderBy = Array.Empty<(ItemSortBy, SortOrder)>();
+            OwnerIds = Array.Empty<Guid>();
             PersonIds = Array.Empty<Guid>();
             PersonTypes = Array.Empty<string>();
             PresetViews = Array.Empty<CollectionType?>();
@@ -369,6 +371,8 @@ namespace MediaBrowser.Controller.Entities
 
         public bool SkipDeserialization { get; set; }
 
+        public bool IncludeExtras { get; set; }
+
         public void SetUser(User user)
         {
             var maxRating = user.MaxParentalRatingScore;
diff --git a/MediaBrowser.Controller/Entities/LinkedChild.cs b/MediaBrowser.Controller/Entities/LinkedChild.cs
index 98e4f525f5..a3aa9dd0c9 100644
--- a/MediaBrowser.Controller/Entities/LinkedChild.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChild.cs
@@ -3,7 +3,6 @@
 #pragma warning disable CS1591
 
 using System;
-using System.Globalization;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -13,10 +12,18 @@ namespace MediaBrowser.Controller.Entities
         {
         }
 
+        /// <summary>
+        /// Gets or sets the path.
+        /// </summary>
+        [Obsolete("Use ItemId instead")]
         public string Path { get; set; }
 
         public LinkedChildType Type { get; set; }
 
+        /// <summary>
+        /// Gets or sets the library item id.
+        /// </summary>
+        [Obsolete("Use ItemId instead")]
         public string LibraryItemId { get; set; }
 
         /// <summary>
@@ -28,18 +35,11 @@ namespace MediaBrowser.Controller.Entities
         {
             ArgumentNullException.ThrowIfNull(item);
 
-            var child = new LinkedChild
+            return new LinkedChild
             {
-                Path = item.Path,
+                ItemId = item.Id,
                 Type = LinkedChildType.Manual
             };
-
-            if (string.IsNullOrEmpty(child.Path))
-            {
-                child.LibraryItemId = item.Id.ToString("N", CultureInfo.InvariantCulture);
-            }
-
-            return child;
         }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
index 4f13ac61fe..8b611345f4 100644
--- a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
@@ -19,17 +19,34 @@ namespace MediaBrowser.Controller.Entities
 
         public bool Equals(LinkedChild x, LinkedChild y)
         {
-            if (x.Type == y.Type)
+            if (x.Type != y.Type)
             {
-                return _fileSystem.AreEqual(x.Path, y.Path);
+                return false;
             }
 
-            return false;
+            // Compare by ItemId first (preferred)
+            if (x.ItemId.HasValue && y.ItemId.HasValue)
+            {
+                return x.ItemId.Value.Equals(y.ItemId.Value);
+            }
+
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for shortcut/legacy comparison
+            // Fall back to Path comparison for shortcuts and legacy data
+            return _fileSystem.AreEqual(x.Path, y.Path);
+#pragma warning restore CS0618
         }
 
         public int GetHashCode(LinkedChild obj)
         {
+            // Use ItemId for hash if available, otherwise fall back to legacy fields
+            if (obj.ItemId.HasValue && !obj.ItemId.Value.Equals(Guid.Empty))
+            {
+                return HashCode.Combine(obj.ItemId.Value, obj.Type);
+            }
+
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for shortcut/legacy hashing
             return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode(StringComparison.Ordinal);
+#pragma warning restore CS0618
         }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildType.cs b/MediaBrowser.Controller/Entities/LinkedChildType.cs
index 3bd260a102..5ce66a561f 100644
--- a/MediaBrowser.Controller/Entities/LinkedChildType.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChildType.cs
@@ -13,6 +13,16 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Shortcut linked child.
         /// </summary>
-        Shortcut = 1
+        Shortcut = 1,
+
+        /// <summary>
+        /// Local alternate version (same item, different file path).
+        /// </summary>
+        LocalAlternateVersion = 2,
+
+        /// <summary>
+        /// Linked alternate version (different item ID).
+        /// </summary>
+        LinkedAlternateVersion = 3
     }
 }
diff --git a/MediaBrowser.Controller/Entities/Movies/BoxSet.cs b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
index 3999c3e076..c55a70a67b 100644
--- a/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
+++ b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
@@ -37,9 +37,7 @@ namespace MediaBrowser.Controller.Entities.Movies
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the display order.
diff --git a/MediaBrowser.Controller/Entities/Movies/Movie.cs b/MediaBrowser.Controller/Entities/Movies/Movie.cs
index 710b05e7f9..797f44e2d5 100644
--- a/MediaBrowser.Controller/Entities/Movies/Movie.cs
+++ b/MediaBrowser.Controller/Entities/Movies/Movie.cs
@@ -4,13 +4,13 @@
 
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Text.Json.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Entities;
-using MediaBrowser.Model.Providers;
 
 namespace MediaBrowser.Controller.Entities.Movies
 {
@@ -28,9 +28,7 @@ namespace MediaBrowser.Controller.Entities.Movies
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the name of the TMDb collection.
@@ -85,6 +83,34 @@ namespace MediaBrowser.Controller.Entities.Movies
             return info;
         }
 
+        protected override async Task RefreshMetadataForVersions(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            var newOptions = new MetadataRefreshOptions(options)
+            {
+                SearchResult = null
+            };
+
+            var id = LibraryManager.GetNewItemId(path, typeof(Movie));
+            if (LibraryManager.GetItemById(id) is not Movie movie)
+            {
+                movie = LibraryManager.ResolvePath(FileSystem.GetFileSystemInfo(path)) as Movie;
+
+                newOptions.ForceSave = true;
+            }
+
+            if (movie is null)
+            {
+                return;
+            }
+
+            if (movie.OwnerId.Equals(Guid.Empty))
+            {
+                movie.OwnerId = Id;
+            }
+
+            await RefreshMetadataForOwnedItem(movie, copyTitleMetadata, newOptions, cancellationToken).ConfigureAwait(false);
+        }
+
         /// <inheritdoc />
         public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
diff --git a/MediaBrowser.Controller/Entities/TV/Episode.cs b/MediaBrowser.Controller/Entities/TV/Episode.cs
index 6bdba36f9c..dbe6f94dfd 100644
--- a/MediaBrowser.Controller/Entities/TV/Episode.cs
+++ b/MediaBrowser.Controller/Entities/TV/Episode.cs
@@ -28,9 +28,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the season in which it aired.
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index 6396631f99..ca9ac3f047 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -52,9 +52,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the display order.
diff --git a/MediaBrowser.Controller/Entities/UserViewBuilder.cs b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
index bed7554b19..47d732c745 100644
--- a/MediaBrowser.Controller/Entities/UserViewBuilder.cs
+++ b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
@@ -16,9 +16,7 @@ using MediaBrowser.Controller.TV;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.Querying;
 using Microsoft.Extensions.Logging;
-using Episode = MediaBrowser.Controller.Entities.TV.Episode;
 using MetadataProvider = MediaBrowser.Model.Entities.MetadataProvider;
-using Series = MediaBrowser.Controller.Entities.TV.Series;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -140,7 +138,7 @@ namespace MediaBrowser.Controller.Entities
 
                 if (query.IncludeItemTypes.Length == 0)
                 {
-                    query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+                    query.IncludeItemTypes = [BaseItemKind.Movie];
                 }
 
                 return parent.QueryRecursive(query);
@@ -165,7 +163,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -176,7 +174,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -187,7 +185,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -198,7 +196,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -206,7 +204,7 @@ namespace MediaBrowser.Controller.Entities
         private QueryResult<BaseItem> GetMovieCollections(User user, InternalItemsQuery query)
         {
             query.Parent = null;
-            query.IncludeItemTypes = new[] { BaseItemKind.BoxSet };
+            query.IncludeItemTypes = [BaseItemKind.BoxSet];
             query.SetUser(user);
             query.Recursive = true;
 
@@ -215,25 +213,25 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetMovieLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
 
         private QueryResult<BaseItem> GetMovieResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
@@ -247,7 +245,7 @@ namespace MediaBrowser.Controller.Entities
         {
             var genres = parent.QueryRecursive(new InternalItemsQuery(user)
             {
-                IncludeItemTypes = new[] { BaseItemKind.Movie },
+                IncludeItemTypes = [BaseItemKind.Movie],
                 Recursive = true,
                 EnableTotalRecordCount = false
             }).Items
@@ -275,10 +273,10 @@ namespace MediaBrowser.Controller.Entities
         {
             query.Recursive = true;
             query.Parent = queryParent;
-            query.GenreIds = new[] { displayParent.Id };
+            query.GenreIds = [displayParent.Id];
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -292,12 +290,12 @@ namespace MediaBrowser.Controller.Entities
 
                 if (query.IncludeItemTypes.Length == 0)
                 {
-                    query.IncludeItemTypes = new[]
-                    {
+                    query.IncludeItemTypes =
+                    [
                         BaseItemKind.Series,
                         BaseItemKind.Season,
                         BaseItemKind.Episode
-                    };
+                    ];
                 }
 
                 return parent.QueryRecursive(query);
@@ -319,12 +317,12 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
             query.IsVirtualItem = false;
 
             return ConvertToResult(_libraryManager.GetItemList(query));
@@ -332,7 +330,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvNextUp(Folder parent, InternalItemsQuery query)
         {
-            var parentFolders = GetMediaFolders(parent, query.User, new[] { CollectionType.tvshows });
+            var parentFolders = GetMediaFolders(parent, query.User, [CollectionType.tvshows]);
 
             var result = _tvSeriesManager.GetNextUp(
                 new NextUpQuery
@@ -349,13 +347,13 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
@@ -366,7 +364,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -375,7 +373,7 @@ namespace MediaBrowser.Controller.Entities
         {
             var genres = parent.QueryRecursive(new InternalItemsQuery(user)
             {
-                IncludeItemTypes = new[] { BaseItemKind.Series },
+                IncludeItemTypes = [BaseItemKind.Series],
                 Recursive = true,
                 EnableTotalRecordCount = false
             }).Items
@@ -403,10 +401,10 @@ namespace MediaBrowser.Controller.Entities
         {
             query.Recursive = true;
             query.Parent = queryParent;
-            query.GenreIds = new[] { displayParent.Id };
+            query.GenreIds = [displayParent.Id];
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -418,7 +416,7 @@ namespace MediaBrowser.Controller.Entities
         {
             items = items.Where(i => Filter(i, query.User, query, _userDataManager, _libraryManager));
 
-            return PostFilterAndSort(items, null, query, _libraryManager);
+            return SortAndPage(items, null, query, _libraryManager);
         }
 
         public static bool FilterItem(BaseItem item, InternalItemsQuery query)
@@ -426,21 +424,6 @@ namespace MediaBrowser.Controller.Entities
             return Filter(item, query.User, query, BaseItem.UserDataManager, BaseItem.LibraryManager);
         }
 
-        public static QueryResult<BaseItem> PostFilterAndSort(
-            IEnumerable<BaseItem> items,
-            int? totalRecordLimit,
-            InternalItemsQuery query,
-            ILibraryManager libraryManager)
-        {
-            // This must be the last filter
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                items = FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
-            }
-
-            return SortAndPage(items, totalRecordLimit, query, libraryManager);
-        }
-
         public static QueryResult<BaseItem> SortAndPage(
             IEnumerable<BaseItem> items,
             int? totalRecordLimit,
@@ -556,38 +539,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.IsPlayed.HasValue)
-            {
-                userData ??= userDataManager.GetUserData(user, item);
-                if (item.IsPlayed(user, userData) != query.IsPlayed.Value)
-                {
-                    return false;
-                }
-            }
-
-            // Filter by Video3DFormat
-            if (query.Is3D.HasValue)
-            {
-                var val = query.Is3D.Value;
-                var video = item as Video;
-
-                if (video is null || val != video.Video3DFormat.HasValue)
-                {
-                    return false;
-                }
-            }
-
-            /*
-             * fuck - fix this
-            if (query.IsHD.HasValue)
-            {
-                if (item.IsHD != query.IsHD.Value)
-                {
-                    return false;
-                }
-            }
-            */
-
             if (query.IsLocked.HasValue)
             {
                 var val = query.IsLocked.Value;
@@ -645,68 +596,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.HasOfficialRating.HasValue)
-            {
-                var filterValue = query.HasOfficialRating.Value;
-
-                var hasValue = !string.IsNullOrEmpty(item.OfficialRating);
-
-                if (hasValue != filterValue)
-                {
-                    return false;
-                }
-            }
-
-            if (query.IsPlaceHolder.HasValue)
-            {
-                var filterValue = query.IsPlaceHolder.Value;
-
-                var isPlaceHolder = false;
-
-                if (item is ISupportsPlaceHolders hasPlaceHolder)
-                {
-                    isPlaceHolder = hasPlaceHolder.IsPlaceHolder;
-                }
-
-                if (isPlaceHolder != filterValue)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasSpecialFeature.HasValue)
-            {
-                var filterValue = query.HasSpecialFeature.Value;
-
-                if (item is IHasSpecialFeatures movie)
-                {
-                    var ok = filterValue
-                        ? movie.SpecialFeatureIds.Count > 0
-                        : movie.SpecialFeatureIds.Count == 0;
-
-                    if (!ok)
-                    {
-                        return false;
-                    }
-                }
-                else
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasSubtitles.HasValue)
-            {
-                var val = query.HasSubtitles.Value;
-
-                var video = item as Video;
-
-                if (video is null || val != video.HasSubtitles)
-                {
-                    return false;
-                }
-            }
-
             if (query.HasParentalRating.HasValue)
             {
                 var val = query.HasParentalRating.Value;
@@ -734,66 +623,12 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.HasTrailer.HasValue)
-            {
-                var val = query.HasTrailer.Value;
-                var trailerCount = 0;
-
-                if (item is IHasTrailers hasTrailers)
-                {
-                    trailerCount = hasTrailers.GetTrailerCount();
-                }
-
-                var ok = val ? trailerCount > 0 : trailerCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasThemeSong.HasValue)
-            {
-                var filterValue = query.HasThemeSong.Value;
-
-                var themeCount = item.GetThemeSongs(user).Count;
-                var ok = filterValue ? themeCount > 0 : themeCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasThemeVideo.HasValue)
-            {
-                var filterValue = query.HasThemeVideo.Value;
-
-                var themeCount = item.GetThemeVideos(user).Count;
-                var ok = filterValue ? themeCount > 0 : themeCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
             // Apply genre filter
             if (query.Genres.Count > 0 && !query.Genres.Any(v => item.Genres.Contains(v, StringComparison.OrdinalIgnoreCase)))
             {
                 return false;
             }
 
-            // Filter by VideoType
-            if (query.VideoTypes.Length > 0)
-            {
-                var video = item as Video;
-                if (video is null || !query.VideoTypes.Contains(video.VideoType))
-                {
-                    return false;
-                }
-            }
-
             if (query.ImageTypes.Length > 0 && !query.ImageTypes.Any(item.HasImage))
             {
                 return false;
@@ -912,30 +747,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.SeriesStatuses.Length > 0)
-            {
-                var ok = new[] { item }.OfType<Series>().Any(p => p.Status.HasValue && query.SeriesStatuses.Contains(p.Status.Value));
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.AiredDuringSeason.HasValue)
-            {
-                var episode = item as Episode;
-
-                if (episode is null)
-                {
-                    return false;
-                }
-
-                if (!Series.FilterEpisodesBySeason(new[] { episode }, query.AiredDuringSeason.Value, true).Any())
-                {
-                    return false;
-                }
-            }
-
             if (query.ExcludeItemIds.Contains(item.Id))
             {
                 return false;
@@ -989,7 +800,7 @@ namespace MediaBrowser.Controller.Entities
                 return GetMediaFolders(user, viewTypes);
             }
 
-            return new BaseItem[] { parent };
+            return [parent];
         }
 
         private UserView GetUserViewWithName(CollectionType? type, string sortName, BaseItem parent)
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index 1043029c6e..1ddc193359 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -160,7 +160,7 @@ namespace MediaBrowser.Controller.Entities
         public bool IsStacked => AdditionalParts.Length > 0;
 
         [JsonIgnore]
-        public override bool HasLocalAlternateVersions => LocalAlternateVersions.Length > 0;
+        public override bool HasLocalAlternateVersions => LibraryManager.GetLocalAlternateVersionIds(this).Any();
 
         public static IRecordingsManager RecordingsManager { get; set; }
 
@@ -260,7 +260,10 @@ namespace MediaBrowser.Controller.Entities
                 {
                     if (callstack.Contains(video.Id))
                     {
-                        return video.LinkedAlternateVersions.Length + video.LocalAlternateVersions.Length + 1;
+                        // Count alternate versions using LibraryManager
+                        var linkedCount = LibraryManager.GetLinkedAlternateVersions(video).Count();
+                        var localCount = LibraryManager.GetLocalAlternateVersionIds(video).Count();
+                        return linkedCount + localCount + 1;
                     }
 
                     callstack.Add(video.Id);
@@ -268,7 +271,10 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            return LinkedAlternateVersions.Length + LocalAlternateVersions.Length + 1;
+            // Count alternate versions using LibraryManager
+            var linkedVersionCount = LibraryManager.GetLinkedAlternateVersions(this).Count();
+            var localVersionCount = LibraryManager.GetLocalAlternateVersionIds(this).Count();
+            return linkedVersionCount + localVersionCount + 1;
         }
 
         public override List<string> GetUserDataKeys()
@@ -364,11 +370,6 @@ namespace MediaBrowser.Controller.Entities
             return AdditionalParts.Select(i => LibraryManager.GetNewItemId(i, typeof(Video)));
         }
 
-        public IEnumerable<Guid> GetLocalAlternateVersionIds()
-        {
-            return LocalAlternateVersions.Select(i => LibraryManager.GetNewItemId(i, typeof(Video)));
-        }
-
         private string GetUserDataKey(string providerId)
         {
             var key = providerId + "-" + ExtraType.ToString().ToLowerInvariant();
@@ -382,15 +383,6 @@ namespace MediaBrowser.Controller.Entities
             return key;
         }
 
-        public IEnumerable<Video> GetLinkedAlternateVersions()
-        {
-            return LinkedAlternateVersions
-                .Select(GetLinkedChild)
-                .Where(i => i is not null)
-                .OfType<Video>()
-                .OrderBy(i => i.SortName);
-        }
-
         /// <summary>
         /// Gets the additional parts.
         /// </summary>
@@ -454,7 +446,7 @@ namespace MediaBrowser.Controller.Entities
                     RefreshLinkedAlternateVersions();
 
                     var tasks = LocalAlternateVersions
-                        .Select(i => RefreshMetadataForOwnedVideo(options, false, i, cancellationToken));
+                        .Select(i => RefreshMetadataForVersions(options, false, i, cancellationToken));
 
                     await Task.WhenAll(tasks).ConfigureAwait(false);
                 }
@@ -463,6 +455,39 @@ namespace MediaBrowser.Controller.Entities
             return hasChanges;
         }
 
+        protected virtual async Task RefreshMetadataForVersions(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            await RefreshMetadataForOwnedVideo(options, copyTitleMetadata, path, cancellationToken).ConfigureAwait(false);
+        }
+
+        private new async Task RefreshMetadataForOwnedVideo(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            var newOptions = new MetadataRefreshOptions(options)
+            {
+                SearchResult = null
+            };
+
+            var id = LibraryManager.GetNewItemId(path, typeof(Video));
+            if (LibraryManager.GetItemById(id) is not Video video)
+            {
+                video = LibraryManager.ResolvePath(FileSystem.GetFileSystemInfo(path)) as Video;
+
+                newOptions.ForceSave = true;
+            }
+
+            if (video is null)
+            {
+                return;
+            }
+
+            if (video.OwnerId.IsEmpty())
+            {
+                video.OwnerId = Id;
+            }
+
+            await RefreshMetadataForOwnedItem(video, copyTitleMetadata, newOptions, cancellationToken).ConfigureAwait(false);
+        }
+
         private void RefreshLinkedAlternateVersions()
         {
             foreach (var child in LinkedAlternateVersions)
@@ -480,7 +505,7 @@ namespace MediaBrowser.Controller.Entities
         {
             await base.UpdateToRepositoryAsync(updateReason, cancellationToken).ConfigureAwait(false);
 
-            var localAlternates = GetLocalAlternateVersionIds()
+            var localAlternates = LibraryManager.GetLocalAlternateVersionIds(this)
                 .Select(i => LibraryManager.GetItemById(i))
                 .Where(i => i is not null);
 
@@ -537,7 +562,7 @@ namespace MediaBrowser.Controller.Entities
                 (this, MediaSourceType.Default)
             };
 
-            list.AddRange(GetLinkedAlternateVersions().Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
+            list.AddRange(LibraryManager.GetLinkedAlternateVersions(this).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
 
             if (!string.IsNullOrEmpty(PrimaryVersionId))
             {
@@ -545,14 +570,14 @@ namespace MediaBrowser.Controller.Entities
                 {
                     var existingIds = list.Select(i => i.Item1.Id).ToList();
                     list.Add((primary, MediaSourceType.Grouping));
-                    list.AddRange(primary.GetLinkedAlternateVersions().Where(i => !existingIds.Contains(i.Id)).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
+                    list.AddRange(LibraryManager.GetLinkedAlternateVersions(primary).Where(i => !existingIds.Contains(i.Id)).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
                 }
             }
 
             var localAlternates = list
                 .SelectMany(i =>
                 {
-                    return i.Item1 is Video video ? video.GetLocalAlternateVersionIds() : Enumerable.Empty<Guid>();
+                    return i.Item1 is Video video ? LibraryManager.GetLocalAlternateVersionIds(video) : Enumerable.Empty<Guid>();
                 })
                 .Select(LibraryManager.GetItemById)
                 .Where(i => i is not null)
diff --git a/MediaBrowser.Controller/Library/ILibraryManager.cs b/MediaBrowser.Controller/Library/ILibraryManager.cs
index df1c98f3f7..c19d15d85f 100644
--- a/MediaBrowser.Controller/Library/ILibraryManager.cs
+++ b/MediaBrowser.Controller/Library/ILibraryManager.cs
@@ -214,6 +214,22 @@ namespace MediaBrowser.Controller.Library
         Task<IEnumerable<Video>> GetIntros(BaseItem item, User user);
 
         /// <summary>
+        /// Gets the IDs of local alternate versions for a video.
+        /// Local alternate versions are alternate quality versions at different file paths.
+        /// </summary>
+        /// <param name="video">The video item.</param>
+        /// <returns>Enumerable of alternate version item IDs.</returns>
+        IEnumerable<Guid> GetLocalAlternateVersionIds(Video video);
+
+        /// <summary>
+        /// Gets the linked alternate versions for a video.
+        /// Linked alternate versions are different items representing the same content (e.g., Director's Cut).
+        /// </summary>
+        /// <param name="video">The video item.</param>
+        /// <returns>Enumerable of linked Video items.</returns>
+        IEnumerable<Video> GetLinkedAlternateVersions(Video video);
+
+        /// <summary>
         /// Adds the parts.
         /// </summary>
         /// <param name="rules">The rules.</param>
@@ -601,6 +617,20 @@ namespace MediaBrowser.Controller.Library
         IReadOnlyList<string> GetNextUpSeriesKeys(InternalItemsQuery query, IReadOnlyCollection<BaseItem> parents, DateTime dateCutoff);
 
         /// <summary>
+        /// Gets next up episodes for multiple series in a single batched query.
+        /// </summary>
+        /// <param name="query">The query filter.</param>
+        /// <param name="seriesKeys">The series presentation unique keys to query.</param>
+        /// <param name="includeSpecials">Whether to include specials for aired episode order sorting.</param>
+        /// <param name="includeWatchedForRewatching">Whether to include watched episodes for rewatching mode.</param>
+        /// <returns>A dictionary mapping series key to batch result.</returns>
+        IReadOnlyDictionary<string, MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+            InternalItemsQuery query,
+            IReadOnlyList<string> seriesKeys,
+            bool includeSpecials,
+            bool includeWatchedForRewatching);
+
+        /// <summary>
         /// Gets the items result.
         /// </summary>
         /// <param name="query">The query.</param>
@@ -649,6 +679,23 @@ namespace MediaBrowser.Controller.Library
 
         ItemCounts GetItemCounts(InternalItemsQuery query);
 
+        /// <summary>
+        /// Batch-fetches child counts for multiple parent folders.
+        /// Returns the count of immediate children (non-recursive) for each parent.
+        /// </summary>
+        /// <param name="parentIds">The list of parent folder IDs.</param>
+        /// <param name="userId">The user ID for access filtering.</param>
+        /// <returns>Dictionary mapping parent ID to child count.</returns>
+        Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId);
+
+        /// <summary>
+        /// Configures the query with user access settings including TopParentIds for library access.
+        /// Call this before passing a query to methods that need user access filtering.
+        /// </summary>
+        /// <param name="query">The query to configure.</param>
+        /// <param name="user">The user to configure access for.</param>
+        void ConfigureUserAccess(InternalItemsQuery query, User user);
+
         Task RunMetadataSavers(BaseItem item, ItemUpdateType updateReason);
 
         BaseItem GetParentItem(Guid? parentId, Guid? userId);
diff --git a/MediaBrowser.Controller/Persistence/IItemRepository.cs b/MediaBrowser.Controller/Persistence/IItemRepository.cs
index bf80b7d0a8..f7ed39730e 100644
--- a/MediaBrowser.Controller/Persistence/IItemRepository.cs
+++ b/MediaBrowser.Controller/Persistence/IItemRepository.cs
@@ -88,6 +88,21 @@ public interface IItemRepository
     IReadOnlyList<string> GetNextUpSeriesKeys(InternalItemsQuery filter, DateTime dateCutoff);
 
     /// <summary>
+    /// Gets next up episodes for multiple series in a single batched query.
+    /// Returns the last watched episode, next unwatched episode, specials, and next played episode for each series.
+    /// </summary>
+    /// <param name="filter">The query filter.</param>
+    /// <param name="seriesKeys">The series presentation unique keys to query.</param>
+    /// <param name="includeSpecials">Whether to include specials (ParentIndexNumber = 0) in the results.</param>
+    /// <param name="includeWatchedForRewatching">Whether to include watched episodes for rewatching mode.</param>
+    /// <returns>A dictionary mapping series key to batch result containing episodes needed for NextUp calculation.</returns>
+    IReadOnlyDictionary<string, NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+        InternalItemsQuery filter,
+        IReadOnlyList<string> seriesKeys,
+        bool includeSpecials,
+        bool includeWatchedForRewatching);
+
+    /// <summary>
     /// Updates the inherited values.
     /// </summary>
     void UpdateInheritedValues();
@@ -133,9 +148,66 @@ public interface IItemRepository
     bool GetIsPlayed(User user, Guid id, bool recursive);
 
     /// <summary>
+    /// Gets the count of played items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>The count of played descendant items.</returns>
+    int GetPlayedCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets the total count of items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>The total count of descendant items.</returns>
+    int GetTotalCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets both the played count and total count of items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>A tuple containing (Played count, Total count).</returns>
+    (int Played, int Total) GetPlayedAndTotalCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets both the played count and total count of items that are linked children of the specified parent.
+    /// Uses the LinkedChildren table for BoxSets, Playlists, etc.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="parentId">The parent item id (BoxSet, Playlist, etc.).</param>
+    /// <returns>A tuple containing (Played count, Total count).</returns>
+    (int Played, int Total) GetPlayedAndTotalCountFromLinkedChildren(InternalItemsQuery filter, Guid parentId);
+
+    /// <summary>
+    /// Gets the IDs of linked children for the specified parent.
+    /// </summary>
+    /// <param name="parentId">The parent item ID.</param>
+    /// <param name="childType">Optional child type filter (e.g., LocalAlternateVersion, LinkedAlternateVersion).</param>
+    /// <returns>List of child item IDs.</returns>
+    IReadOnlyList<Guid> GetLinkedChildrenIds(Guid parentId, int? childType = null);
+
+    /// <summary>
     /// Gets all artist matches from the db.
     /// </summary>
     /// <param name="artistNames">The names of the artists.</param>
     /// <returns>A map of the artist name and the potential matches.</returns>
     IReadOnlyDictionary<string, MusicArtist[]> FindArtists(IReadOnlyList<string> artistNames);
+
+    /// <summary>
+    /// Batch-fetches child counts for multiple parent folders.
+    /// Returns the count of immediate children (non-recursive) for each parent.
+    /// </summary>
+    /// <param name="parentIds">The list of parent folder IDs.</param>
+    /// <param name="userId">The user ID for access filtering.</param>
+    /// <returns>Dictionary mapping parent ID to child count.</returns>
+    Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId);
 }
diff --git a/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs b/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs
new file mode 100644
index 0000000000..f5b09498b9
--- /dev/null
+++ b/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs
@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Persistence;
+
+/// <summary>
+/// Result of a batched NextUp query for a single series.
+/// </summary>
+public sealed class NextUpEpisodeBatchResult
+{
+    /// <summary>
+    /// Gets or sets the last watched episode (highest season/episode that is played).
+    /// </summary>
+    public BaseItem? LastWatched { get; set; }
+
+    /// <summary>
+    /// Gets or sets the next unwatched episode after the last watched position.
+    /// </summary>
+    public BaseItem? NextUp { get; set; }
+
+    /// <summary>
+    /// Gets or sets specials that may air between episodes.
+    /// Only populated when includeSpecials is true.
+    /// </summary>
+    public IReadOnlyList<BaseItem>? Specials { get; set; }
+
+    /// <summary>
+    /// Gets or sets the last watched episode for rewatching mode (most recently played).
+    /// Only populated when includeWatchedForRewatching is true.
+    /// </summary>
+    public BaseItem? LastWatchedForRewatching { get; set; }
+
+    /// <summary>
+    /// Gets or sets the next played episode for rewatching mode.
+    /// Only populated when includeWatchedForRewatching is true.
+    /// </summary>
+    public BaseItem? NextPlayedForRewatching { get; set; }
+}