Merge pull request #16062 from Shadowghost/perf-rebased

Query Performance Improvements

20 files changed, 877 insertions, 438 deletions

diff --git a/Emby.Server.Implementations/ApplicationHost.cs b/Emby.Server.Implementations/ApplicationHost.cs
index cbb0f6c565..e8cab6ea8c 100644
--- a/Emby.Server.Implementations/ApplicationHost.cs
+++ b/Emby.Server.Implementations/ApplicationHost.cs
@@ -507,7 +507,13 @@ namespace Emby.Server.Implementations
 
             serviceCollection.AddSingleton<IUserDataManager, UserDataManager>();
 
-            serviceCollection.AddSingleton<IItemRepository, BaseItemRepository>();
+            serviceCollection.AddSingleton<BaseItemRepository>();
+            serviceCollection.AddSingleton<IItemRepository>(sp => sp.GetRequiredService<BaseItemRepository>());
+            serviceCollection.AddSingleton<IItemQueryHelpers>(sp => sp.GetRequiredService<BaseItemRepository>());
+            serviceCollection.AddSingleton<IItemPersistenceService, ItemPersistenceService>();
+            serviceCollection.AddSingleton<INextUpService, NextUpService>();
+            serviceCollection.AddSingleton<IItemCountService, ItemCountService>();
+            serviceCollection.AddSingleton<ILinkedChildrenService, LinkedChildrenService>();
             serviceCollection.AddSingleton<IPeopleRepository, PeopleRepository>();
             serviceCollection.AddSingleton<IChapterRepository, ChapterRepository>();
             serviceCollection.AddSingleton<IMediaAttachmentRepository, MediaAttachmentRepository>();
@@ -641,6 +647,7 @@ namespace Emby.Server.Implementations
             BaseItem.ConfigurationManager = ConfigurationManager;
             BaseItem.FileSystem = Resolve<IFileSystem>();
             BaseItem.ItemRepository = Resolve<IItemRepository>();
+            BaseItem.ItemCountService = Resolve<IItemCountService>();
             BaseItem.LibraryManager = Resolve<ILibraryManager>();
             BaseItem.LocalizationManager = Resolve<ILocalizationManager>();
             BaseItem.Logger = Resolve<ILogger<BaseItem>>();
diff --git a/Emby.Server.Implementations/Collections/CollectionManager.cs b/Emby.Server.Implementations/Collections/CollectionManager.cs
index a320a774c6..0ede5665f9 100644
--- a/Emby.Server.Implementations/Collections/CollectionManager.cs
+++ b/Emby.Server.Implementations/Collections/CollectionManager.cs
@@ -272,7 +272,7 @@ namespace Emby.Server.Implementations.Collections
             {
                 var childItem = _libraryManager.GetItemById(guidId);
 
-                var child = collection.LinkedChildren.FirstOrDefault(i => (i.ItemId.HasValue && i.ItemId.Value.Equals(guidId)) || (childItem is not null && string.Equals(childItem.Path, i.Path, StringComparison.OrdinalIgnoreCase)));
+                var child = collection.LinkedChildren.FirstOrDefault(i => i.ItemId.HasValue && i.ItemId.Value.Equals(guidId));
 
                 if (child is null)
                 {
@@ -342,7 +342,7 @@ namespace Emby.Server.Implementations.Collections
                     // this is kind of a performance hack because only Video has alternate versions that should be in a box set?
                     if (item is Video video)
                     {
-                        foreach (var childId in video.GetLocalAlternateVersionIds())
+                        foreach (var childId in _libraryManager.GetLocalAlternateVersionIds(video))
                         {
                             if (!results.ContainsKey(childId))
                             {
diff --git a/Emby.Server.Implementations/Data/CleanDatabaseScheduledTask.cs b/Emby.Server.Implementations/Data/CleanDatabaseScheduledTask.cs
index 676bb7f816..17355960c3 100644
--- a/Emby.Server.Implementations/Data/CleanDatabaseScheduledTask.cs
+++ b/Emby.Server.Implementations/Data/CleanDatabaseScheduledTask.cs
@@ -5,10 +5,12 @@ using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Jellyfin.Data.Enums;
 using Jellyfin.Database.Implementations;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Playlists;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 
@@ -35,7 +37,11 @@ public class CleanDatabaseScheduledTask : ILibraryPostScanTask
 
     public async Task Run(IProgress<double> progress, CancellationToken cancellationToken)
     {
-        await CleanDeadItems(cancellationToken, progress).ConfigureAwait(false);
+        var deadItemsProgress = new Progress<double>(val => progress.Report(val * 0.8));
+        await CleanDeadItems(cancellationToken, deadItemsProgress).ConfigureAwait(false);
+
+        var playlistProgress = new Progress<double>(val => progress.Report(80 + (val * 0.2)));
+        await CleanOrphanedFilePlaylistsAsync(cancellationToken, playlistProgress).ConfigureAwait(false);
     }
 
     private async Task CleanDeadItems(CancellationToken cancellationToken, IProgress<double> progress)
@@ -116,4 +122,32 @@ public class CleanDatabaseScheduledTask : ILibraryPostScanTask
 
         progress.Report(100);
     }
+
+    private async Task CleanOrphanedFilePlaylistsAsync(CancellationToken cancellationToken, IProgress<double> progress)
+    {
+        var playlists = _libraryManager.GetItemList(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.Playlist],
+            Recursive = true
+        }).OfType<Playlist>().ToList();
+
+        var numComplete = 0;
+        var numItems = Math.Max(playlists.Count, 1);
+
+        foreach (var playlist in playlists)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            if (playlist.IsFile && !File.Exists(playlist.Path))
+            {
+                _logger.LogInformation("Removing file-based playlist {Name} because source file {Path} no longer exists", playlist.Name, playlist.Path);
+                _libraryManager.DeleteItem(playlist, new DeleteOptions { DeleteFileLocation = false });
+            }
+
+            numComplete++;
+            progress.Report((double)numComplete / numItems * 100);
+        }
+
+        progress.Report(100);
+    }
 }
diff --git a/Emby.Server.Implementations/Dto/DtoService.cs b/Emby.Server.Implementations/Dto/DtoService.cs
index 9f62ad5a91..cc57d183b6 100644
--- a/Emby.Server.Implementations/Dto/DtoService.cs
+++ b/Emby.Server.Implementations/Dto/DtoService.cs
@@ -153,17 +153,68 @@ namespace Emby.Server.Implementations.Dto
         private ILiveTvManager LivetvManager => _livetvManagerFactory.Value;
 
         /// <inheritdoc />
-        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null)
+        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(
+            IReadOnlyList<BaseItem> items,
+            DtoOptions options,
+            User? user = null,
+            BaseItem? owner = null,
+            bool skipVisibilityCheck = false)
         {
-            var accessibleItems = user is null ? items : items.Where(x => x.IsVisible(user)).ToList();
+            var accessibleItems = skipVisibilityCheck || user is null ? items : items.Where(x => x.IsVisible(user)).ToList();
             var returnItems = new BaseItemDto[accessibleItems.Count];
             List<(BaseItem, BaseItemDto)>? programTuples = null;
             List<(BaseItemDto, LiveTvChannel)>? channelTuples = null;
 
+            // Batch-fetch user data for all items
+            Dictionary<Guid, UserItemData>? userDataBatch = null;
+            if (user is not null && options.EnableUserData)
+            {
+                userDataBatch = _userDataRepository.GetUserDataBatch(accessibleItems, user);
+            }
+
+            // Pre-compute collection folders once to avoid N+1 queries in CanDelete
+            List<Folder>? allCollectionFolders = null;
+            if (user is not null && options.ContainsField(ItemFields.CanDelete))
+            {
+                allCollectionFolders = _libraryManager.GetUserRootFolder().Children.OfType<Folder>().ToList();
+            }
+
+            // Batch-fetch child counts for all folders to avoid N+1 queries
+            Dictionary<Guid, int>? childCountBatch = null;
+            if (options.ContainsField(ItemFields.ChildCount))
+            {
+                var folderIds = accessibleItems.OfType<Folder>().Select(f => f.Id).ToList();
+                if (folderIds.Count > 0)
+                {
+                    childCountBatch = _libraryManager.GetChildCountBatch(folderIds, user?.Id);
+                }
+            }
+
+            // Batch-fetch played/total counts for all folders to avoid N+1 queries
+            Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null;
+            if (user is not null && options.EnableUserData)
+            {
+                var folderIds = accessibleItems.OfType<Folder>()
+                    .Where(f => f.SupportsUserDataFromChildren && (f.SupportsPlayedStatus || options.ContainsField(ItemFields.RecursiveItemCount)))
+                    .Select(f => f.Id).ToList();
+                if (folderIds.Count > 0)
+                {
+                    playedCountBatch = _libraryManager.GetPlayedAndTotalCountBatch(folderIds, user);
+                }
+            }
+
             for (int index = 0; index < accessibleItems.Count; index++)
             {
                 var item = accessibleItems[index];
-                var dto = GetBaseItemDtoInternal(item, options, user, owner);
+                var dto = GetBaseItemDtoInternal(
+                    item,
+                    options,
+                    user,
+                    owner,
+                    userDataBatch?.GetValueOrDefault(item.Id),
+                    allCollectionFolders,
+                    childCountBatch,
+                    playedCountBatch);
 
                 if (item is LiveTvChannel tvChannel)
                 {
@@ -197,7 +248,7 @@ namespace Emby.Server.Implementations.Dto
 
         public BaseItemDto GetBaseItemDto(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
         {
-            var dto = GetBaseItemDtoInternal(item, options, user, owner);
+            var dto = GetBaseItemDtoInternal(item, options, user, owner, null);
             if (item is LiveTvChannel tvChannel)
             {
                 LivetvManager.AddChannelInfo(new[] { (dto, tvChannel) }, options, user);
@@ -215,7 +266,15 @@ namespace Emby.Server.Implementations.Dto
             return dto;
         }
 
-        private BaseItemDto GetBaseItemDtoInternal(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
+        private BaseItemDto GetBaseItemDtoInternal(
+            BaseItem item,
+            DtoOptions options,
+            User? user = null,
+            BaseItem? owner = null,
+            UserItemData? userData = null,
+            List<Folder>? allCollectionFolders = null,
+            Dictionary<Guid, int>? childCountBatch = null,
+            Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null)
         {
             var dto = new BaseItemDto
             {
@@ -252,7 +311,14 @@ namespace Emby.Server.Implementations.Dto
 
             if (user is not null)
             {
-                AttachUserSpecificInfo(dto, item, user, options);
+                AttachUserSpecificInfo(
+                    dto,
+                    item,
+                    user,
+                    options,
+                    userData,
+                    childCountBatch,
+                    playedCountBatch);
             }
 
             if (item is IHasMediaSources
@@ -274,7 +340,9 @@ namespace Emby.Server.Implementations.Dto
             {
                 dto.CanDelete = user is null
                     ? item.CanDelete()
-                    : item.CanDelete(user);
+                    : allCollectionFolders is not null
+                        ? item.CanDelete(user, allCollectionFolders)
+                        : item.CanDelete(user);
             }
 
             if (options.ContainsField(ItemFields.CanDownload))
@@ -378,37 +446,7 @@ namespace Emby.Server.Implementations.Dto
                 return;
             }
 
-            var query = new InternalItemsQuery(user)
-            {
-                Recursive = true,
-                DtoOptions = new DtoOptions(false) { EnableImages = false },
-                IncludeItemTypes = relatedItemKinds
-            };
-
-            switch (dto.Type)
-            {
-                case BaseItemKind.Genre:
-                case BaseItemKind.MusicGenre:
-                    query.GenreIds = [dto.Id];
-                    break;
-                case BaseItemKind.MusicArtist:
-                    query.ArtistIds = [dto.Id];
-                    break;
-                case BaseItemKind.Person:
-                    query.PersonIds = [dto.Id];
-                    break;
-                case BaseItemKind.Studio:
-                    query.StudioIds = [dto.Id];
-                    break;
-                case BaseItemKind.Year
-                    when int.TryParse(dto.Name, NumberStyles.Integer, CultureInfo.InvariantCulture, out var year):
-                    query.Years = [year];
-                    break;
-                default:
-                    return;
-            }
-
-            var counts = _libraryManager.GetItemCounts(query);
+            var counts = _libraryManager.GetItemCountsForNameItem(dto.Type, dto.Id, relatedItemKinds, user);
 
             dto.AlbumCount = counts.AlbumCount;
             dto.ArtistCount = counts.ArtistCount;
@@ -458,7 +496,14 @@ namespace Emby.Server.Implementations.Dto
         /// <summary>
         /// Attaches the user specific info.
         /// </summary>
-        private void AttachUserSpecificInfo(BaseItemDto dto, BaseItem item, User user, DtoOptions options)
+        private void AttachUserSpecificInfo(
+            BaseItemDto dto,
+            BaseItem item,
+            User user,
+            DtoOptions options,
+            UserItemData? userData = null,
+            Dictionary<Guid, int>? childCountBatch = null,
+            Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null)
         {
             if (item.IsFolder)
             {
@@ -466,7 +511,19 @@ namespace Emby.Server.Implementations.Dto
 
                 if (options.EnableUserData)
                 {
-                    dto.UserData = _userDataRepository.GetUserDataDto(item, dto, user, options);
+                    if (userData is not null)
+                    {
+                        // Use pre-fetched user data
+                        dto.UserData = GetUserItemDataDto(userData, item.Id);
+                        (int Played, int Total)? precomputed = playedCountBatch is not null
+                            && playedCountBatch.TryGetValue(item.Id, out var counts) ? counts : null;
+                        item.FillUserDataDtoValues(dto.UserData, userData, dto, user, options, precomputed);
+                    }
+                    else
+                    {
+                        // Fall back to individual fetch
+                        dto.UserData = _userDataRepository.GetUserDataDto(item, dto, user, options);
+                    }
                 }
 
                 if (!dto.ChildCount.HasValue && item.SourceType == SourceType.Library)
@@ -485,7 +542,7 @@ namespace Emby.Server.Implementations.Dto
 
                     if (options.ContainsField(ItemFields.ChildCount))
                     {
-                        dto.ChildCount ??= GetChildCount(folder, user);
+                        dto.ChildCount ??= GetChildCount(folder, user, childCountBatch);
                     }
                 }
 
@@ -503,7 +560,17 @@ namespace Emby.Server.Implementations.Dto
             {
                 if (options.EnableUserData)
                 {
-                    dto.UserData = _userDataRepository.GetUserDataDto(item, user);
+                    if (userData is not null)
+                    {
+                        // Use pre-fetched user data
+                        dto.UserData = GetUserItemDataDto(userData, item.Id);
+                        item.FillUserDataDtoValues(dto.UserData, userData, dto, user, options);
+                    }
+                    else
+                    {
+                        // Fall back to individual fetch
+                        dto.UserData = _userDataRepository.GetUserDataDto(item, user);
+                    }
                 }
             }
 
@@ -513,7 +580,25 @@ namespace Emby.Server.Implementations.Dto
             }
         }
 
-        private static int GetChildCount(Folder folder, User user)
+        private static UserItemDataDto GetUserItemDataDto(UserItemData data, Guid itemId)
+        {
+            ArgumentNullException.ThrowIfNull(data);
+
+            return new UserItemDataDto
+            {
+                IsFavorite = data.IsFavorite,
+                Likes = data.Likes,
+                PlaybackPositionTicks = data.PlaybackPositionTicks,
+                PlayCount = data.PlayCount,
+                Rating = data.Rating,
+                Played = data.Played,
+                LastPlayedDate = data.LastPlayedDate,
+                ItemId = itemId,
+                Key = data.Key
+            };
+        }
+
+        private static int GetChildCount(Folder folder, User user, Dictionary<Guid, int>? childCountBatch)
         {
             // Right now this is too slow to calculate for top level folders on a per-user basis
             // Just return something so that apps that are expecting a value won't think the folders are empty
@@ -522,6 +607,13 @@ namespace Emby.Server.Implementations.Dto
                 return Random.Shared.Next(1, 10);
             }
 
+            // Use pre-fetched batch data if available
+            if (childCountBatch is not null && childCountBatch.TryGetValue(folder.Id, out var count))
+            {
+                return count;
+            }
+
+            // Fall back to individual query for special cases (Series, Season, etc.)
             return folder.GetChildCount(user);
         }
 
diff --git a/Emby.Server.Implementations/IO/ManagedFileSystem.cs b/Emby.Server.Implementations/IO/ManagedFileSystem.cs
index 4d68cb4444..199407044b 100644
--- a/Emby.Server.Implementations/IO/ManagedFileSystem.cs
+++ b/Emby.Server.Implementations/IO/ManagedFileSystem.cs
@@ -586,6 +586,12 @@ namespace Emby.Server.Implementations.IO
         /// <inheritdoc />
         public virtual IEnumerable<FileSystemMetadata> GetFiles(string path, string searchPattern, IReadOnlyList<string>? extensions, bool enableCaseSensitiveExtensions, bool recursive = false)
         {
+            if (!Directory.Exists(path))
+            {
+                _logger.LogWarning("Directory does not exist: {Path}", path);
+                return [];
+            }
+
             var enumerationOptions = GetEnumerationOptions(recursive);
 
             // On linux and macOS the search pattern is case-sensitive
diff --git a/Emby.Server.Implementations/Library/LibraryManager.cs b/Emby.Server.Implementations/Library/LibraryManager.cs
index eee87c4d8b..2bcb10e9e1 100644
--- a/Emby.Server.Implementations/Library/LibraryManager.cs
+++ b/Emby.Server.Implementations/Library/LibraryManager.cs
@@ -34,14 +34,11 @@ using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.LiveTv;
 using MediaBrowser.Controller.MediaEncoding;
-using MediaBrowser.Controller.MediaSegments;
 using MediaBrowser.Controller.Persistence;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Controller.Resolvers;
 using MediaBrowser.Controller.Sorting;
-using MediaBrowser.Controller.Trickplay;
 using MediaBrowser.Model.Configuration;
-using MediaBrowser.Model.Dlna;
 using MediaBrowser.Model.Drawing;
 using MediaBrowser.Model.Dto;
 using MediaBrowser.Model.Entities;
@@ -77,6 +74,10 @@ namespace Emby.Server.Implementations.Library
         private readonly IMediaEncoder _mediaEncoder;
         private readonly IFileSystem _fileSystem;
         private readonly IItemRepository _itemRepository;
+        private readonly IItemPersistenceService _persistenceService;
+        private readonly INextUpService _nextUpService;
+        private readonly IItemCountService _countService;
+        private readonly ILinkedChildrenService _linkedChildrenService;
         private readonly IImageProcessor _imageProcessor;
         private readonly NamingOptions _namingOptions;
         private readonly IPeopleRepository _peopleRepository;
@@ -115,6 +116,10 @@ namespace Emby.Server.Implementations.Library
         /// <param name="userViewManagerFactory">The user view manager.</param>
         /// <param name="mediaEncoder">The media encoder.</param>
         /// <param name="itemRepository">The item repository.</param>
+        /// <param name="persistenceService">The item persistence service.</param>
+        /// <param name="nextUpService">The next up service.</param>
+        /// <param name="countService">The item count service.</param>
+        /// <param name="linkedChildrenService">The linked children service.</param>
         /// <param name="imageProcessor">The image processor.</param>
         /// <param name="namingOptions">The naming options.</param>
         /// <param name="directoryService">The directory service.</param>
@@ -133,6 +138,10 @@ namespace Emby.Server.Implementations.Library
             Lazy<IUserViewManager> userViewManagerFactory,
             IMediaEncoder mediaEncoder,
             IItemRepository itemRepository,
+            IItemPersistenceService persistenceService,
+            INextUpService nextUpService,
+            IItemCountService countService,
+            ILinkedChildrenService linkedChildrenService,
             IImageProcessor imageProcessor,
             NamingOptions namingOptions,
             IDirectoryService directoryService,
@@ -151,6 +160,10 @@ namespace Emby.Server.Implementations.Library
             _userViewManagerFactory = userViewManagerFactory;
             _mediaEncoder = mediaEncoder;
             _itemRepository = itemRepository;
+            _persistenceService = persistenceService;
+            _nextUpService = nextUpService;
+            _countService = countService;
+            _linkedChildrenService = linkedChildrenService;
             _imageProcessor = imageProcessor;
 
             _cache = new FastConcurrentLru<Guid, BaseItem>(_configurationManager.Configuration.CacheSize);
@@ -327,9 +340,17 @@ namespace Emby.Server.Implementations.Library
             DeleteItem(item, options, parent, notifyParentItem);
         }
 
-        public void DeleteItemsUnsafeFast(IEnumerable<BaseItem> items)
+        public void DeleteItemsUnsafeFast(IReadOnlyCollection<BaseItem> items, bool deleteSourceFiles = false)
         {
-            var pathMaps = items.Select(e => (Item: e, InternalPath: GetInternalMetadataPaths(e), DeletePaths: e.GetDeletePaths())).ToArray();
+            if (items.Count == 0)
+            {
+                return;
+            }
+
+            var pathMaps = items.Select(e =>
+                (Item: e,
+                InternalPath: GetInternalMetadataPaths(e),
+                DeletePaths: deleteSourceFiles ? e.GetDeletePaths() : [])).ToArray();
 
             foreach (var (item, internalPaths, pathsToDelete) in pathMaps)
             {
@@ -363,7 +384,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            _itemRepository.DeleteItem([.. pathMaps.Select(f => f.Item.Id)]);
+            _persistenceService.DeleteItem([.. pathMaps.Select(f => f.Item.Id)]);
         }
 
         public void DeleteItem(BaseItem item, DeleteOptions options, BaseItem parent, bool notifyParentItem)
@@ -406,6 +427,99 @@ namespace Emby.Server.Implementations.Library
                     item.Id);
             }
 
+            // If deleting a primary version video, clear PrimaryVersionId from alternate versions
+            // OwnerId check: items with OwnerId set are alternate versions or extras, not primaries
+            if (item is Video video && !video.PrimaryVersionId.HasValue && video.OwnerId.IsEmpty())
+            {
+                var localAlternateIds = GetLocalAlternateVersionIds(video).ToHashSet();
+                var allAlternateVersions = localAlternateIds
+                    .Concat(GetLinkedAlternateVersions(video).Select(v => v.Id))
+                    .Distinct()
+                    .Select(id => GetItemById(id))
+                    .OfType<Video>()
+                    .ToList();
+
+                // Partition alternates by whether their files still exist on disk
+                var alternateVersions = new List<Video>();
+                var missingAlternates = new List<Video>();
+                foreach (var alt in allAlternateVersions)
+                {
+                    if (!string.IsNullOrEmpty(alt.Path) && !_fileSystem.FileExists(alt.Path))
+                    {
+                        missingAlternates.Add(alt);
+                    }
+                    else
+                    {
+                        alternateVersions.Add(alt);
+                    }
+                }
+
+                // Delete alternates whose files no longer exist to avoid ghost items.
+                // Clear PrimaryVersionId first so DeleteItem doesn't try to update the primary being deleted.
+                foreach (var missing in missingAlternates)
+                {
+                    _logger.LogInformation(
+                        "Deleting missing alternate version {Name} ({Path})",
+                        missing.Name ?? "Unknown name",
+                        missing.Path ?? string.Empty);
+                    missing.SetPrimaryVersionId(null);
+                    missing.OwnerId = Guid.Empty;
+                    missing.LocalAlternateVersions = [];
+                    missing.LinkedAlternateVersions = [];
+                    DeleteItem(missing, new DeleteOptions { DeleteFileLocation = false }, false);
+                }
+
+                if (alternateVersions.Count > 0)
+                {
+                    _logger.LogInformation(
+                        "Clearing PrimaryVersionId from {Count} alternate versions of {Name}",
+                        alternateVersions.Count,
+                        item.Name ?? "Unknown name");
+
+                    // Promote the first alternate version to be the new primary
+                    var newPrimary = alternateVersions[0];
+                    newPrimary.SetPrimaryVersionId(null);
+                    newPrimary.OwnerId = Guid.Empty;
+
+                    // Transfer alternate version arrays from old primary to new primary
+                    // so UpdateToRepositoryAsync creates correct LinkedChildren entries
+                    newPrimary.LocalAlternateVersions = video.LocalAlternateVersions
+                        .Where(p => !string.Equals(p, newPrimary.Path, StringComparison.OrdinalIgnoreCase))
+                        .ToArray();
+                    newPrimary.LinkedAlternateVersions = video.LinkedAlternateVersions
+                        .Where(lc => !lc.ItemId.HasValue || !lc.ItemId.Value.Equals(newPrimary.Id))
+                        .ToArray();
+
+                    newPrimary.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).GetAwaiter().GetResult();
+
+                    // Re-route playlist/collection references from deleted primary to new primary
+                    RerouteLinkedChildReferencesAsync(video.Id, newPrimary.Id).GetAwaiter().GetResult();
+
+                    // Update remaining alternates to point to new primary
+                    foreach (var alternate in alternateVersions.Skip(1))
+                    {
+                        alternate.SetPrimaryVersionId(newPrimary.Id);
+                        // Only set OwnerId for local alternates; linked alternates are independent items
+                        alternate.OwnerId = localAlternateIds.Contains(alternate.Id) ? newPrimary.Id : Guid.Empty;
+                        alternate.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).GetAwaiter().GetResult();
+                    }
+                }
+            }
+            else if (item is Video alternateVideo && alternateVideo.PrimaryVersionId.HasValue)
+            {
+                // If deleting an alternate version, re-route references to its primary
+                RerouteLinkedChildReferencesAsync(alternateVideo.Id, alternateVideo.PrimaryVersionId.Value).GetAwaiter().GetResult();
+
+                // Remove deleted alternate from primary's LinkedAlternateVersions
+                if (GetItemById(alternateVideo.PrimaryVersionId.Value) is Video primaryVideo)
+                {
+                    primaryVideo.LinkedAlternateVersions = primaryVideo.LinkedAlternateVersions
+                        .Where(lc => !lc.ItemId.HasValue || !lc.ItemId.Value.Equals(alternateVideo.Id))
+                        .ToArray();
+                    primaryVideo.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).GetAwaiter().GetResult();
+                }
+            }
+
             var children = item.IsFolder
                 ? ((Folder)item).GetRecursiveChildren(false)
                 : [];
@@ -450,7 +564,7 @@ namespace Emby.Server.Implementations.Library
 
             item.SetParent(null);
 
-            _itemRepository.DeleteItem([item.Id, .. children.Select(f => f.Id)]);
+            _persistenceService.DeleteItem([item.Id, .. children.Select(f => f.Id)]);
             _cache.TryRemove(item.Id, out _);
             foreach (var child in children)
             {
@@ -576,6 +690,9 @@ namespace Emby.Server.Implementations.Library
                 // Trickplay
                 list.Add(_pathManager.GetTrickplayDirectory(video));
 
+                // Chapter Images
+                list.Add(_pathManager.GetChapterImageFolderPath(video));
+
                 // Subtitles and attachments
                 foreach (var mediaSource in item.GetMediaSources(false))
                 {
@@ -657,8 +774,63 @@ namespace Emby.Server.Implementations.Library
             return key.GetMD5();
         }
 
-        public BaseItem? ResolvePath(FileSystemMetadata fileInfo, Folder? parent = null, IDirectoryService? directoryService = null)
-            => ResolvePath(fileInfo, directoryService ?? new DirectoryService(_fileSystem), null, parent);
+        public BaseItem? ResolvePath(
+            FileSystemMetadata fileInfo,
+            Folder? parent = null,
+            IDirectoryService? directoryService = null,
+            CollectionType? collectionType = null)
+            => ResolvePath(fileInfo, directoryService ?? new DirectoryService(_fileSystem), null, parent, collectionType);
+
+        /// <inheritdoc />
+        public Video? ResolveAlternateVersion(string path, Type expectedVideoType, Folder? parent, CollectionType? collectionType)
+        {
+            // Clean up any existing item saved with wrong type (e.g. Video instead of Movie).
+            // This happens when items were previously resolved without proper type context
+            // in mixed-content libraries where collectionType is null.
+            var expectedId = GetNewItemId(path, expectedVideoType);
+            if (expectedVideoType != typeof(Video))
+            {
+                var wrongTypeId = GetNewItemId(path, typeof(Video));
+                if (!wrongTypeId.Equals(expectedId) && GetItemById(wrongTypeId) is Video wrongTypeItem)
+                {
+                    _logger.LogInformation(
+                        "Removing alternate version with wrong type {WrongType}, expected {ExpectedType}: {Path}",
+                        wrongTypeItem.GetType().Name,
+                        expectedVideoType.Name,
+                        path);
+                    DeleteItem(wrongTypeItem, new DeleteOptions { DeleteFileLocation = false });
+                }
+            }
+
+            var resolved = ResolvePath(
+                _fileSystem.GetFileSystemInfo(path),
+                parent,
+                collectionType: collectionType) as Video;
+
+            if (resolved is null)
+            {
+                return null;
+            }
+
+            // Ensure the alternate version has the same concrete type as the primary video.
+            // ResolvePath may return a generic Video for files in mixed-content libraries
+            // where collectionType is null, even though the primary is a Movie/Episode/etc.
+            if (resolved.GetType() != expectedVideoType)
+            {
+                if (Activator.CreateInstance(expectedVideoType) is Video correctVideo)
+                {
+                    correctVideo.Path = resolved.Path;
+                    correctVideo.Name = resolved.Name;
+                    correctVideo.VideoType = resolved.VideoType;
+                    correctVideo.ProductionYear = resolved.ProductionYear;
+                    correctVideo.ExtraType = resolved.ExtraType;
+                    resolved = correctVideo;
+                }
+            }
+
+            resolved.Id = expectedId;
+            return resolved;
+        }
 
         private BaseItem? ResolvePath(
             FileSystemMetadata fileInfo,
@@ -1041,7 +1213,7 @@ namespace Emby.Server.Implementations.Library
 
         public IReadOnlyDictionary<string, MusicArtist[]> GetArtists(IReadOnlyList<string> names)
         {
-            return _itemRepository.FindArtists(names);
+            return _linkedChildrenService.FindArtists(names);
         }
 
         public MusicArtist GetArtist(string name, DtoOptions options)
@@ -1186,7 +1358,7 @@ namespace Emby.Server.Implementations.Library
 
             if (toDelete.Count > 0)
             {
-                _itemRepository.DeleteItem(toDelete.ToArray());
+                _persistenceService.DeleteItem(toDelete.ToArray());
             }
         }
 
@@ -1262,7 +1434,7 @@ namespace Emby.Server.Implementations.Library
                 progress.Report(percent * 100);
             }
 
-            _itemRepository.UpdateInheritedValues();
+            _persistenceService.UpdateInheritedValues();
 
             progress.Report(100);
         }
@@ -1421,14 +1593,7 @@ namespace Emby.Server.Implementations.Library
                 AddUserToQuery(query, query.User, allowExternalContent);
             }
 
-            var itemList = _itemRepository.GetItemList(query);
-            var user = query.User;
-            if (user is not null)
-            {
-                return itemList.Where(i => i.IsVisible(user)).ToList();
-            }
-
-            return itemList;
+            return _itemRepository.GetItemList(query);
         }
 
         public IReadOnlyList<BaseItem> GetItemList(InternalItemsQuery query)
@@ -1452,7 +1617,7 @@ namespace Emby.Server.Implementations.Library
                 AddUserToQuery(query, query.User);
             }
 
-            return _itemRepository.GetCount(query);
+            return _countService.GetCount(query);
         }
 
         public ItemCounts GetItemCounts(InternalItemsQuery query)
@@ -1471,7 +1636,30 @@ namespace Emby.Server.Implementations.Library
                 AddUserToQuery(query, query.User);
             }
 
-            return _itemRepository.GetItemCounts(query);
+            return _countService.GetItemCounts(query);
+        }
+
+        /// <inheritdoc/>
+        public ItemCounts GetItemCountsForNameItem(BaseItemKind kind, Guid id, BaseItemKind[] relatedItemKinds, User? user)
+        {
+            var query = new InternalItemsQuery(user);
+            if (user is not null)
+            {
+                AddUserToQuery(query, user);
+            }
+
+            return _countService.GetItemCountsForNameItem(kind, id, relatedItemKinds, query);
+        }
+
+        public Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId)
+        {
+            return _countService.GetChildCountBatch(parentIds, userId);
+        }
+
+        /// <inheritdoc/>
+        public Dictionary<Guid, (int Played, int Total)> GetPlayedAndTotalCountBatch(IReadOnlyList<Guid> folderIds, User user)
+        {
+            return _countService.GetPlayedAndTotalCountBatch(folderIds, user);
         }
 
         public IReadOnlyList<BaseItem> GetItemList(InternalItemsQuery query, List<BaseItem> parents)
@@ -1516,7 +1704,17 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            return _itemRepository.GetNextUpSeriesKeys(query, dateCutoff);
+            return _nextUpService.GetNextUpSeriesKeys(query, dateCutoff);
+        }
+
+        /// <inheritdoc />
+        public IReadOnlyDictionary<string, MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+            InternalItemsQuery query,
+            IReadOnlyList<string> seriesKeys,
+            bool includeSpecials,
+            bool includeWatchedForRewatching)
+        {
+            return _nextUpService.GetNextUpEpisodesBatch(query, seriesKeys, includeSpecials, includeWatchedForRewatching);
         }
 
         public QueryResult<BaseItem> QueryItems(InternalItemsQuery query)
@@ -1700,6 +1898,11 @@ namespace Emby.Server.Implementations.Library
 
         private void AddUserToQuery(InternalItemsQuery query, User user, bool allowExternalContent = true)
         {
+            if (query.User is null)
+            {
+                query.SetUser(user);
+            }
+
             if (query.AncestorIds.Length == 0 &&
                 query.ParentId.IsEmpty() &&
                 query.ChannelIds.Count == 0 &&
@@ -1725,6 +1928,15 @@ namespace Emby.Server.Implementations.Library
             }
         }
 
+        /// <inheritdoc/>
+        public void ConfigureUserAccess(InternalItemsQuery query, User user)
+        {
+            ArgumentNullException.ThrowIfNull(query);
+            ArgumentNullException.ThrowIfNull(user);
+
+            AddUserToQuery(query, user);
+        }
+
         private IEnumerable<Guid> GetTopParentIdsForQuery(BaseItem item, User? user)
         {
             if (item is UserView view)
@@ -1890,6 +2102,44 @@ namespace Emby.Server.Implementations.Library
         }
 
         /// <inheritdoc />
+        public IEnumerable<Guid> GetLocalAlternateVersionIds(Video video)
+        {
+            ArgumentNullException.ThrowIfNull(video);
+
+            var linkedIds = _linkedChildrenService.GetLinkedChildrenIds(video.Id, (int)MediaBrowser.Controller.Entities.LinkedChildType.LocalAlternateVersion);
+            if (linkedIds.Count > 0)
+            {
+                return linkedIds;
+            }
+
+            return [];
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<Video> GetLinkedAlternateVersions(Video video)
+        {
+            ArgumentNullException.ThrowIfNull(video);
+
+            var linkedIds = _linkedChildrenService.GetLinkedChildrenIds(video.Id, (int)MediaBrowser.Controller.Entities.LinkedChildType.LinkedAlternateVersion);
+            if (linkedIds.Count > 0)
+            {
+                return linkedIds
+                    .Select(id => GetItemById(id))
+                    .Where(i => i is not null)
+                    .OfType<Video>()
+                    .OrderBy(i => i.SortName);
+            }
+
+            return [];
+        }
+
+        /// <inheritdoc />
+        public void UpsertLinkedChild(Guid parentId, Guid childId, MediaBrowser.Controller.Entities.LinkedChildType childType)
+        {
+            _linkedChildrenService.UpsertLinkedChild(parentId, childId, childType);
+        }
+
+        /// <inheritdoc />
         public IEnumerable<BaseItem> Sort(IEnumerable<BaseItem> items, User? user, IEnumerable<ItemSortBy> sortBy, SortOrder sortOrder)
         {
             IOrderedEnumerable<BaseItem>? orderedItems = null;
@@ -1993,10 +2243,45 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public void CreateItems(IReadOnlyList<BaseItem> items, BaseItem? parent, CancellationToken cancellationToken)
         {
-            _itemRepository.SaveItems(items, cancellationToken);
-
+            // Resolve and add any local alternate version items that don't exist yet
+            // This ensures they exist in the database when LinkedChildren are processed
+            var allItems = new List<BaseItem>(items);
+            var parentFolder = parent as Folder;
+            var parentCollectionType = parent is not null ? GetTopFolderContentType(parent) : null;
             foreach (var item in items)
             {
+                if (item is Video video && video.LocalAlternateVersions.Length > 0)
+                {
+                    var videoType = video.GetType();
+                    foreach (var path in video.LocalAlternateVersions)
+                    {
+                        if (string.IsNullOrEmpty(path))
+                        {
+                            continue;
+                        }
+
+                        // Use the primary video's type for ID calculation to ensure consistency
+                        var altId = GetNewItemId(path, videoType);
+                        if (GetItemById(altId) is null && !allItems.Any(i => i.Id.Equals(altId)))
+                        {
+                            // Alternate version doesn't exist, resolve and create it
+                            // ensuring it has the same type as the primary video
+                            var altVideo = ResolveAlternateVersion(path, videoType, parentFolder, parentCollectionType);
+                            if (altVideo is not null)
+                            {
+                                altVideo.OwnerId = video.Id;
+                                altVideo.SetPrimaryVersionId(video.Id);
+                                allItems.Add(altVideo);
+                            }
+                        }
+                    }
+                }
+            }
+
+            _persistenceService.SaveItems(allItems, cancellationToken);
+
+            foreach (var item in allItems)
+            {
                 RegisterItem(item);
             }
 
@@ -2144,7 +2429,7 @@ namespace Emby.Server.Implementations.Library
 
             item.ValidateImages();
 
-            await _itemRepository.SaveImagesAsync(item).ConfigureAwait(false);
+            await _persistenceService.SaveImagesAsync(item).ConfigureAwait(false);
 
             RegisterItem(item);
         }
@@ -2161,7 +2446,50 @@ namespace Emby.Server.Implementations.Library
                 item.DateLastSaved = DateTime.UtcNow;
             }
 
-            _itemRepository.SaveItems(items, cancellationToken);
+            // Resolve and add any local alternate version items that don't exist yet
+            // This ensures they exist in the database when LinkedChildren are processed
+            var allItems = new List<BaseItem>(items);
+            var parentFolder = parent as Folder;
+            var parentCollectionType = GetTopFolderContentType(parent);
+            foreach (var item in items)
+            {
+                if (item is Video video && video.LocalAlternateVersions.Length > 0)
+                {
+                    var videoType = video.GetType();
+                    foreach (var path in video.LocalAlternateVersions)
+                    {
+                        if (string.IsNullOrEmpty(path))
+                        {
+                            continue;
+                        }
+
+                        // Use the primary video's type for ID calculation to ensure consistency
+                        var altId = GetNewItemId(path, videoType);
+                        if (GetItemById(altId) is null && !allItems.Any(i => i.Id.Equals(altId)))
+                        {
+                            // Alternate version doesn't exist, resolve and create it
+                            // ensuring it has the same type as the primary video
+                            var altVideo = ResolveAlternateVersion(path, videoType, parentFolder, parentCollectionType);
+                            if (altVideo is not null)
+                            {
+                                altVideo.OwnerId = video.Id;
+                                altVideo.SetPrimaryVersionId(video.Id);
+                                allItems.Add(altVideo);
+                            }
+                        }
+                    }
+                }
+            }
+
+            _persistenceService.SaveItems(allItems, cancellationToken);
+
+            foreach (var item in allItems)
+            {
+                if (!items.Contains(item))
+                {
+                    RegisterItem(item);
+                }
+            }
 
             if (parent is Folder folder)
             {
@@ -2205,7 +2533,7 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public async Task ReattachUserDataAsync(BaseItem item, CancellationToken cancellationToken)
         {
-            await _itemRepository.ReattachUserDataAsync(item, cancellationToken).ConfigureAwait(false);
+            await _persistenceService.ReattachUserDataAsync(item, cancellationToken).ConfigureAwait(false);
         }
 
         public async Task RunMetadataSavers(BaseItem item, ItemUpdateType updateReason)
@@ -2834,7 +3162,8 @@ namespace Emby.Server.Implementations.Library
         {
             // Apply .ignore rules
             var filtered = fileSystemChildren.Where(c => !DotIgnoreIgnoreRule.IsIgnored(c, owner)).ToList();
-            var ownerVideoInfo = VideoResolver.Resolve(owner.Path, owner.IsFolder, _namingOptions, libraryRoot: owner.ContainingFolderPath);
+            var isFolder = owner.IsFolder || (owner is Video video && (video.VideoType == VideoType.BluRay || video.VideoType == VideoType.Dvd));
+            var ownerVideoInfo = VideoResolver.Resolve(owner.Path, isFolder, _namingOptions, libraryRoot: owner.ContainingFolderPath);
             if (ownerVideoInfo is null)
             {
                 yield break;
@@ -2896,10 +3225,16 @@ namespace Emby.Server.Implementations.Library
                     extra.ExtraType = extraType;
                 }
 
-                extra.ParentId = Guid.Empty;
-                extra.OwnerId = owner.Id;
-                extra.IsInMixedFolder = isInMixedFolder;
-                return extra;
+                // Only return items that are actual extras (have ExtraType set)
+                // Note: OwnerId and ParentId are set by RefreshExtras, not here,
+                // so that RefreshExtras can detect when they need updating and set ForceSave.
+                if (extra.ExtraType is not null)
+                {
+                    extra.IsInMixedFolder = isInMixedFolder;
+                    return extra;
+                }
+
+                return null;
             }
         }
 
@@ -3385,5 +3720,40 @@ namespace Emby.Server.Implementations.Library
             _fileSystem.CreateShortcut(lnk, _appHost.ReverseVirtualPath(path));
             RemoveContentTypeOverrides(path);
         }
+
+        /// <inheritdoc />
+        public async Task RerouteLinkedChildReferencesAsync(Guid fromChildId, Guid toChildId)
+        {
+            var affectedParentIds = _linkedChildrenService.RerouteLinkedChildren(fromChildId, toChildId);
+
+            // Update in-memory LinkedChildren and re-save metadata (NFO) for affected parents
+            foreach (var parentId in affectedParentIds)
+            {
+                if (GetItemById(parentId) is Folder parent)
+                {
+                    foreach (var lc in parent.LinkedChildren)
+                    {
+                        if (lc.ItemId.HasValue && lc.ItemId.Value.Equals(fromChildId))
+                        {
+                            lc.ItemId = toChildId;
+                        }
+                    }
+
+                    await RunMetadataSavers(parent, ItemUpdateType.MetadataEdit).ConfigureAwait(false);
+                }
+            }
+        }
+
+        /// <inheritdoc />
+        public QueryFiltersLegacy GetQueryFiltersLegacy(InternalItemsQuery query)
+        {
+            if (query.User is not null)
+            {
+                AddUserToQuery(query, query.User);
+            }
+
+            SetTopParentOrAncestorIds(query);
+            return _itemRepository.GetQueryFiltersLegacy(query);
+        }
     }
 }
diff --git a/Emby.Server.Implementations/Library/UserDataManager.cs b/Emby.Server.Implementations/Library/UserDataManager.cs
index 72c8d7a9d2..1281f1587f 100644
--- a/Emby.Server.Implementations/Library/UserDataManager.cs
+++ b/Emby.Server.Implementations/Library/UserDataManager.cs
@@ -177,53 +177,74 @@ namespace Emby.Server.Implementations.Library
             };
         }
 
-        private UserItemData? GetUserData(User user, Guid itemId, List<string> keys)
+        /// <inheritdoc />
+        public Dictionary<Guid, UserItemData> GetUserDataBatch(IReadOnlyList<BaseItem> items, User user)
         {
-            var cacheKey = GetCacheKey(user.InternalId, itemId);
+            var result = new Dictionary<Guid, UserItemData>(items.Count);
+            var itemsNeedingQuery = new List<(BaseItem Item, List<string> Keys)>();
 
-            if (_cache.TryGet(cacheKey, out var data))
+            foreach (var item in items)
             {
-                return data;
-            }
-
-            data = GetUserDataInternal(user.Id, itemId, keys);
-
-            if (data is null)
-            {
-                return new UserItemData()
+                var cacheKey = GetCacheKey(user.InternalId, item.Id);
+                if (_cache.TryGet(cacheKey, out var cachedData))
                 {
-                    Key = keys[0],
-                };
+                    result[item.Id] = cachedData;
+                }
+                else
+                {
+                    var userData = item.UserData?.Where(e => e.UserId.Equals(user.Id)).Select(Map).FirstOrDefault();
+                    if (userData is not null)
+                    {
+                        result[item.Id] = userData;
+                        _cache.AddOrUpdate(cacheKey, userData);
+                    }
+                    else
+                    {
+                        var keys = item.GetUserDataKeys();
+                        itemsNeedingQuery.Add((item, keys));
+                    }
+                }
             }
 
-            return _cache.GetOrAdd(cacheKey, _ => data);
-        }
-
-        private UserItemData? GetUserDataInternal(Guid userId, Guid itemId, List<string> keys)
-        {
-            if (keys.Count == 0)
+            if (itemsNeedingQuery.Count == 0)
             {
-                return null;
+                return result;
             }
 
-            using var context = _repository.CreateDbContext();
-            var userData = context.UserData.AsNoTracking().Where(e => e.ItemId == itemId && keys.Contains(e.CustomDataKey) && e.UserId.Equals(userId)).ToArray();
-
-            if (userData.Length > 0)
+            // Build a single query for all missing items
+            var allItemIds = itemsNeedingQuery.Select(x => x.Item.Id).ToList();
+            var allKeys = itemsNeedingQuery.SelectMany(x => x.Keys).Distinct().ToList();
+            if (allKeys.Count > 0)
             {
-                var directDataReference = userData.FirstOrDefault(e => e.CustomDataKey == itemId.ToString("N"));
-                if (directDataReference is not null)
+                using var context = _repository.CreateDbContext();
+                var userDataArray = context.UserData
+                    .AsNoTracking()
+                    .Where(e => e.UserId.Equals(user.Id))
+                    .WhereOneOrMany(allItemIds, e => e.ItemId)
+                    .WhereOneOrMany(allKeys, e => e.CustomDataKey)
+                    .ToArray();
+
+                var userDataByItem = userDataArray.GroupBy(e => e.ItemId).ToDictionary(g => g.Key, g => g.ToArray());
+                foreach (var (item, keys) in itemsNeedingQuery)
                 {
-                    return Map(directDataReference);
-                }
+                    UserItemData userData;
+                    if (userDataByItem.TryGetValue(item.Id, out var itemUserData) && itemUserData.Length > 0)
+                    {
+                        var directDataReference = itemUserData.FirstOrDefault(e => e.CustomDataKey == item.Id.ToString("N"));
+                        userData = directDataReference is not null ? Map(directDataReference) : Map(itemUserData.First());
+                    }
+                    else
+                    {
+                        userData = new UserItemData { Key = keys.Count > 0 ? keys[0] : string.Empty };
+                    }
 
-                return Map(userData.First());
+                    result[item.Id] = userData;
+                    var cacheKey = GetCacheKey(user.InternalId, item.Id);
+                    _cache.AddOrUpdate(cacheKey, userData);
+                }
             }
 
-            return new UserItemData
-            {
-                Key = keys.Last()!
-            };
+            return result;
         }
 
         /// <summary>
diff --git a/Emby.Server.Implementations/Library/UserViewManager.cs b/Emby.Server.Implementations/Library/UserViewManager.cs
index 6fb53ff15d..9512b0ffd7 100644
--- a/Emby.Server.Implementations/Library/UserViewManager.cs
+++ b/Emby.Server.Implementations/Library/UserViewManager.cs
@@ -59,8 +59,8 @@ namespace Emby.Server.Implementations.Library
                 var collectionFolder = folder as ICollectionFolder;
                 var folderViewType = collectionFolder?.CollectionType;
 
-                // Playlist library requires special handling because the folder only references user playlists
-                if (folderViewType == CollectionType.playlists)
+                // Playlist and BoxSet libraries require special handling because the folder only references linked items
+                if (folderViewType == CollectionType.playlists || folderViewType == CollectionType.boxsets)
                 {
                     var items = folder.GetItemList(new InternalItemsQuery(user)
                     {
@@ -138,7 +138,7 @@ namespace Emby.Server.Implementations.Library
                 list = list.Where(i => !user.GetPreferenceValues<Guid>(PreferenceKind.MyMediaExcludes).Contains(i.Id)).ToList();
             }
 
-            var sorted = _libraryManager.Sort(list, user, new[] { ItemSortBy.SortName }, SortOrder.Ascending).ToList();
+            var sorted = _libraryManager.Sort(list, user, [ItemSortBy.SortName], SortOrder.Ascending).ToList();
             var orders = user.GetPreferenceValues<Guid>(PreferenceKind.OrderedViews);
 
             return list
@@ -205,7 +205,7 @@ namespace Emby.Server.Implementations.Library
             var libraryItems = GetItemsForLatestItems(request.User, request, options);
 
             var list = new List<Tuple<BaseItem, List<BaseItem>>>();
-
+            var containerIndexMap = new Dictionary<Guid, int>();
             foreach (var item in libraryItems)
             {
                 // Only grab the index container for media
@@ -213,20 +213,16 @@ namespace Emby.Server.Implementations.Library
 
                 if (container is null)
                 {
-                    list.Add(new Tuple<BaseItem, List<BaseItem>>(null, new List<BaseItem> { item }));
+                    list.Add(new Tuple<BaseItem, List<BaseItem>>(null!, new List<BaseItem> { item }));
+                }
+                else if (containerIndexMap.TryGetValue(container.Id, out var existingIndex))
+                {
+                    list[existingIndex].Item2.Add(item);
                 }
                 else
                 {
-                    var current = list.FirstOrDefault(i => i.Item1 is not null && i.Item1.Id.Equals(container.Id));
-
-                    if (current is not null)
-                    {
-                        current.Item2.Add(item);
-                    }
-                    else
-                    {
-                        list.Add(new Tuple<BaseItem, List<BaseItem>>(container, new List<BaseItem> { item }));
-                    }
+                    containerIndexMap[container.Id] = list.Count;
+                    list.Add(new Tuple<BaseItem, List<BaseItem>>(container, new List<BaseItem> { item }));
                 }
 
                 if (list.Count >= request.Limit)
@@ -255,7 +251,7 @@ namespace Emby.Server.Implementations.Library
                     return _channelManager.GetLatestChannelItemsInternal(
                         new InternalItemsQuery(user)
                         {
-                            ChannelIds = new[] { parentId },
+                            ChannelIds = [parentId],
                             IsPlayed = request.IsPlayed,
                             StartIndex = request.StartIndex,
                             Limit = request.Limit,
@@ -301,11 +297,11 @@ namespace Emby.Server.Implementations.Library
                 {
                     if (hasCollectionType.All(i => i.CollectionType == CollectionType.movies))
                     {
-                        includeItemTypes = new[] { BaseItemKind.Movie };
+                        includeItemTypes = [BaseItemKind.Movie];
                     }
                     else if (hasCollectionType.All(i => i.CollectionType == CollectionType.tvshows))
                     {
-                        includeItemTypes = new[] { BaseItemKind.Episode };
+                        includeItemTypes = [BaseItemKind.Episode];
                     }
                 }
             }
@@ -344,29 +340,29 @@ namespace Emby.Server.Implementations.Library
             }
 
             var excludeItemTypes = includeItemTypes.Length == 0 && mediaTypes.Length == 0
-                ? new[]
-                {
+                ?
+                [
                     BaseItemKind.Person,
                     BaseItemKind.Studio,
                     BaseItemKind.Year,
                     BaseItemKind.MusicGenre,
                     BaseItemKind.Genre
-                }
+                ]
                 : Array.Empty<BaseItemKind>();
 
             var query = new InternalItemsQuery(user)
             {
                 IncludeItemTypes = includeItemTypes,
-                OrderBy = new[]
-                {
+                OrderBy =
+                [
                     (ItemSortBy.DateCreated, SortOrder.Descending),
                     (ItemSortBy.SortName, SortOrder.Descending),
                     (ItemSortBy.ProductionYear, SortOrder.Descending)
-                },
+                ],
                 IsFolder = includeItemTypes.Length == 0 ? false : null,
                 ExcludeItemTypes = excludeItemTypes,
                 IsVirtualItem = false,
-                Limit = limit * 5,
+                Limit = limit * 2,
                 IsPlayed = isPlayed,
                 DtoOptions = options,
                 MediaTypes = mediaTypes
@@ -394,6 +390,12 @@ namespace Emby.Server.Implementations.Library
                     query.Limit = limit;
                     return _libraryManager.GetLatestItemList(query, parents, CollectionType.music);
                 }
+
+                if (collectionType == CollectionType.movies)
+                {
+                    query.Limit = limit;
+                    return _libraryManager.GetLatestItemList(query, parents, CollectionType.movies);
+                }
             }
 
             return _libraryManager.GetItemList(query, parents);
diff --git a/Emby.Server.Implementations/Library/Validators/ArtistsValidator.cs b/Emby.Server.Implementations/Library/Validators/ArtistsValidator.cs
index ef20ae9bca..fa7112eb90 100644
--- a/Emby.Server.Implementations/Library/Validators/ArtistsValidator.cs
+++ b/Emby.Server.Implementations/Library/Validators/ArtistsValidator.cs
@@ -55,25 +55,35 @@ public class ArtistsValidator
             IncludeItemTypes = [BaseItemKind.MusicArtist]
         }).ToHashSet();
 
+        var existingArtists = _libraryManager.GetArtists(names);
+
         var numComplete = 0;
         var count = names.Count;
+        var refreshed = 0;
 
         foreach (var name in names)
         {
             try
             {
-                var item = _libraryManager.GetArtist(name);
+                MusicArtist? item = null;
+                if (existingArtists.TryGetValue(name, out var artists) && artists.Length > 0)
+                {
+                    item = artists.OrderBy(i => i.IsAccessedByName ? 1 : 0).First();
+                }
+
+                // Fall back to GetArtist if not found (creates new item if needed)
+                item ??= _libraryManager.GetArtist(name);
                 var isNew = !existingArtistIds.Contains(item.Id);
                 var neverRefreshed = item.DateLastRefreshed == default;
 
                 if (isNew || neverRefreshed)
                 {
                     await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                    refreshed++;
                 }
             }
             catch (OperationCanceledException)
             {
-                // Don't clutter the log
                 throw;
             }
             catch (Exception ex)
@@ -89,31 +99,24 @@ public class ArtistsValidator
             progress.Report(percent);
         }
 
+        _logger.LogInformation("Refreshed metadata for {RefreshedCount} new artists out of {TotalCount} total", refreshed, count);
+
         var deadEntities = _libraryManager.GetItemList(new InternalItemsQuery
         {
             IncludeItemTypes = [BaseItemKind.MusicArtist],
             IsDeadArtist = true,
             IsLocked = false
-        }).Cast<MusicArtist>().ToList();
+        }).Cast<MusicArtist>()
+        .Where(item => item.IsAccessedByName)
+        .ToList();
 
         foreach (var item in deadEntities)
         {
-            if (!item.IsAccessedByName)
-            {
-                continue;
-            }
-
             _logger.LogInformation("Deleting dead {ItemType} {ItemId} {ItemName}", item.GetType().Name, item.Id.ToString("N", CultureInfo.InvariantCulture), item.Name);
-
-            _libraryManager.DeleteItem(
-                item,
-                new DeleteOptions
-                {
-                    DeleteFileLocation = false
-                },
-                false);
         }
 
+        _libraryManager.DeleteItemsUnsafeFast(deadEntities, deleteSourceFiles: true);
+
         progress.Report(100);
     }
 }
diff --git a/Emby.Server.Implementations/Library/Validators/CollectionPostScanTask.cs b/Emby.Server.Implementations/Library/Validators/CollectionPostScanTask.cs
index e62c638ed6..e3ef75b9ee 100644
--- a/Emby.Server.Implementations/Library/Validators/CollectionPostScanTask.cs
+++ b/Emby.Server.Implementations/Library/Validators/CollectionPostScanTask.cs
@@ -74,7 +74,7 @@ public class CollectionPostScanTask : ILibraryPostScanTask
 
                 foreach (var m in movies)
                 {
-                    if (m is Movie movie && !string.IsNullOrEmpty(movie.CollectionName))
+                    if (m is Movie movie && !string.IsNullOrEmpty(movie.CollectionName) && !movie.PrimaryVersionId.HasValue)
                     {
                         if (collectionNameMoviesMap.TryGetValue(movie.CollectionName, out var movieList))
                         {
diff --git a/Emby.Server.Implementations/Library/Validators/GenresValidator.cs b/Emby.Server.Implementations/Library/Validators/GenresValidator.cs
index fbfc9f7d54..fc5a2fa0c5 100644
--- a/Emby.Server.Implementations/Library/Validators/GenresValidator.cs
+++ b/Emby.Server.Implementations/Library/Validators/GenresValidator.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
@@ -48,17 +49,40 @@ public class GenresValidator
     public async Task Run(IProgress<double> progress, CancellationToken cancellationToken)
     {
         var names = _itemRepo.GetGenreNames();
+        var existingGenreIds = _libraryManager.GetItemIds(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.Genre]
+        }).ToHashSet();
+
+        var existingGenres = _libraryManager.GetItemList(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.Genre]
+        }).Cast<Genre>()
+        .GroupBy(g => g.Name, StringComparer.OrdinalIgnoreCase)
+        .ToDictionary(g => g.Key, g => g.First(), StringComparer.OrdinalIgnoreCase);
 
         var numComplete = 0;
         var count = names.Count;
+        var refreshed = 0;
 
         foreach (var name in names)
         {
             try
             {
-                var item = _libraryManager.GetGenre(name);
+                Genre? item = null;
+                if (existingGenres.TryGetValue(name, out var existingGenre))
+                {
+                    item = existingGenre;
+                }
+
+                // Fall back to GetGenre if not found (creates new item if needed)
+                item ??= _libraryManager.GetGenre(name);
 
-                await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                if (!existingGenreIds.Contains(item.Id))
+                {
+                    await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                    refreshed++;
+                }
             }
             catch (OperationCanceledException)
             {
@@ -78,6 +102,8 @@ public class GenresValidator
             progress.Report(percent);
         }
 
+        _logger.LogInformation("Refreshed metadata for {RefreshedCount} new genres out of {TotalCount} total", refreshed, count);
+
         var deadEntities = _libraryManager.GetItemList(new InternalItemsQuery
         {
             IncludeItemTypes = [BaseItemKind.Genre, BaseItemKind.MusicGenre],
@@ -88,16 +114,10 @@ public class GenresValidator
         foreach (var item in deadEntities)
         {
             _logger.LogInformation("Deleting dead {ItemType} {ItemId} {ItemName}", item.GetType().Name, item.Id.ToString("N", CultureInfo.InvariantCulture), item.Name);
-
-            _libraryManager.DeleteItem(
-                item,
-                new DeleteOptions
-                {
-                    DeleteFileLocation = false
-                },
-                false);
         }
 
+        _libraryManager.DeleteItemsUnsafeFast(deadEntities, deleteSourceFiles: true);
+
         progress.Report(100);
     }
 }
diff --git a/Emby.Server.Implementations/Library/Validators/MusicGenresValidator.cs b/Emby.Server.Implementations/Library/Validators/MusicGenresValidator.cs
index 6203bce2bc..4365707529 100644
--- a/Emby.Server.Implementations/Library/Validators/MusicGenresValidator.cs
+++ b/Emby.Server.Implementations/Library/Validators/MusicGenresValidator.cs
@@ -1,6 +1,9 @@
 using System;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Jellyfin.Data.Enums;
+using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Persistence;
 using Microsoft.Extensions.Logging;
@@ -45,17 +48,25 @@ public class MusicGenresValidator
     public async Task Run(IProgress<double> progress, CancellationToken cancellationToken)
     {
         var names = _itemRepo.GetMusicGenreNames();
+        var existingMusicGenreIds = _libraryManager.GetItemIds(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.MusicGenre]
+        }).ToHashSet();
 
         var numComplete = 0;
         var count = names.Count;
+        var refreshed = 0;
 
         foreach (var name in names)
         {
             try
             {
                 var item = _libraryManager.GetMusicGenre(name);
-
-                await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                if (!existingMusicGenreIds.Contains(item.Id))
+                {
+                    await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                    refreshed++;
+                }
             }
             catch (OperationCanceledException)
             {
@@ -75,6 +86,8 @@ public class MusicGenresValidator
             progress.Report(percent);
         }
 
+        _logger.LogInformation("Refreshed metadata for {RefreshedCount} new music genres out of {TotalCount} total", refreshed, count);
+
         progress.Report(100);
     }
 }
diff --git a/Emby.Server.Implementations/Library/Validators/PeopleValidator.cs b/Emby.Server.Implementations/Library/Validators/PeopleValidator.cs
index f9a6f0d19e..dacef102dd 100644
--- a/Emby.Server.Implementations/Library/Validators/PeopleValidator.cs
+++ b/Emby.Server.Implementations/Library/Validators/PeopleValidator.cs
@@ -109,7 +109,7 @@ public class PeopleValidator
         var i = 0;
         foreach (var item in deadEntities.Chunk(500))
         {
-            _libraryManager.DeleteItemsUnsafeFast(item);
+            _libraryManager.DeleteItemsUnsafeFast(item, true);
             subProgress.Report(100f / deadEntities.Count * (i++ * 100));
         }
 
diff --git a/Emby.Server.Implementations/Library/Validators/StudiosValidator.cs b/Emby.Server.Implementations/Library/Validators/StudiosValidator.cs
index 5b87e4d9d0..88f86ae6ca 100644
--- a/Emby.Server.Implementations/Library/Validators/StudiosValidator.cs
+++ b/Emby.Server.Implementations/Library/Validators/StudiosValidator.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
@@ -49,17 +50,40 @@ public class StudiosValidator
     public async Task Run(IProgress<double> progress, CancellationToken cancellationToken)
     {
         var names = _itemRepo.GetStudioNames();
+        var existingStudioIds = _libraryManager.GetItemIds(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.Studio]
+        }).ToHashSet();
+
+        var existingStudios = _libraryManager.GetItemList(new InternalItemsQuery
+        {
+            IncludeItemTypes = [BaseItemKind.Studio]
+        }).Cast<Studio>()
+        .GroupBy(s => s.Name, StringComparer.OrdinalIgnoreCase)
+        .ToDictionary(g => g.Key, g => g.First(), StringComparer.OrdinalIgnoreCase);
 
         var numComplete = 0;
         var count = names.Count;
+        var refreshed = 0;
 
         foreach (var name in names)
         {
             try
             {
-                var item = _libraryManager.GetStudio(name);
+                Studio? item = null;
+                if (existingStudios.TryGetValue(name, out var existingStudio))
+                {
+                    item = existingStudio;
+                }
+
+                // Fall back to GetStudio if not found (creates new item if needed)
+                item ??= _libraryManager.GetStudio(name);
 
-                await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                if (!existingStudioIds.Contains(item.Id))
+                {
+                    await item.RefreshMetadata(cancellationToken).ConfigureAwait(false);
+                    refreshed++;
+                }
             }
             catch (OperationCanceledException)
             {
@@ -79,6 +103,8 @@ public class StudiosValidator
             progress.Report(percent);
         }
 
+        _logger.LogInformation("Refreshed metadata for {RefreshedCount} new studios out of {TotalCount} total", refreshed, count);
+
         var deadEntities = _libraryManager.GetItemList(new InternalItemsQuery
         {
             IncludeItemTypes = [BaseItemKind.Studio],
@@ -89,16 +115,10 @@ public class StudiosValidator
         foreach (var item in deadEntities)
         {
             _logger.LogInformation("Deleting dead {ItemType} {ItemId} {ItemName}", item.GetType().Name, item.Id.ToString("N", CultureInfo.InvariantCulture), item.Name);
-
-            _libraryManager.DeleteItem(
-                item,
-                new DeleteOptions
-                {
-                    DeleteFileLocation = false
-                },
-                false);
         }
 
+        _libraryManager.DeleteItemsUnsafeFast(deadEntities, deleteSourceFiles: true);
+
         progress.Report(100);
     }
 }
diff --git a/Emby.Server.Implementations/Localization/Core/en-US.json b/Emby.Server.Implementations/Localization/Core/en-US.json
index c09d5af96c..45b1cbb6a0 100644
--- a/Emby.Server.Implementations/Localization/Core/en-US.json
+++ b/Emby.Server.Implementations/Localization/Core/en-US.json
@@ -130,8 +130,6 @@
     "TaskOptimizeDatabaseDescription": "Compacts database and truncates free space. Running this task after scanning the library or doing other changes that imply database modifications might improve performance.",
     "TaskKeyframeExtractor": "Keyframe Extractor",
     "TaskKeyframeExtractorDescription": "Extracts keyframes from video files to create more precise HLS playlists. This task may run for a long time.",
-    "TaskCleanCollectionsAndPlaylists": "Clean up collections and playlists",
-    "TaskCleanCollectionsAndPlaylistsDescription": "Removes items from collections and playlists that no longer exist.",
     "TaskExtractMediaSegments": "Media Segment Scan",
     "TaskExtractMediaSegmentsDescription": "Extracts or obtains media segments from MediaSegment enabled plugins.",
     "TaskMoveTrickplayImages": "Migrate Trickplay Image Location",
diff --git a/Emby.Server.Implementations/Playlists/PlaylistsFolder.cs b/Emby.Server.Implementations/Playlists/PlaylistsFolder.cs
index a5be2b616e..3bbbdd43a0 100644
--- a/Emby.Server.Implementations/Playlists/PlaylistsFolder.cs
+++ b/Emby.Server.Implementations/Playlists/PlaylistsFolder.cs
@@ -43,8 +43,9 @@ namespace Emby.Server.Implementations.Playlists
             }
 
             query.Recursive = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Playlist };
-            return QueryWithPostFiltering2(query);
+            query.IncludeItemTypes = [BaseItemKind.Playlist];
+
+            return QueryWithPostFiltering(query);
         }
 
         public override string GetClientTypeName()
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/AudioNormalizationTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/AudioNormalizationTask.cs
index 36708e2582..b2dc89be28 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Tasks/AudioNormalizationTask.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Tasks/AudioNormalizationTask.cs
@@ -26,7 +26,7 @@ namespace Emby.Server.Implementations.ScheduledTasks.Tasks;
 /// </summary>
 public partial class AudioNormalizationTask : IScheduledTask
 {
-    private readonly IItemRepository _itemRepository;
+    private readonly IItemPersistenceService _persistenceService;
     private readonly ILibraryManager _libraryManager;
     private readonly IMediaEncoder _mediaEncoder;
     private readonly IApplicationPaths _applicationPaths;
@@ -38,21 +38,21 @@ public partial class AudioNormalizationTask : IScheduledTask
     /// <summary>
     /// Initializes a new instance of the <see cref="AudioNormalizationTask"/> class.
     /// </summary>
-    /// <param name="itemRepository">Instance of the <see cref="IItemRepository"/> interface.</param>
+    /// <param name="persistenceService">Instance of the <see cref="IItemPersistenceService"/> interface.</param>
     /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     /// <param name="mediaEncoder">Instance of the <see cref="IMediaEncoder"/> interface.</param>
     /// <param name="applicationPaths">Instance of the <see cref="IApplicationPaths"/> interface.</param>
     /// <param name="localizationManager">Instance of the <see cref="ILocalizationManager"/> interface.</param>
     /// <param name="logger">Instance of the <see cref="ILogger{AudioNormalizationTask}"/> interface.</param>
     public AudioNormalizationTask(
-        IItemRepository itemRepository,
+        IItemPersistenceService persistenceService,
         ILibraryManager libraryManager,
         IMediaEncoder mediaEncoder,
         IApplicationPaths applicationPaths,
         ILocalizationManager localizationManager,
         ILogger<AudioNormalizationTask> logger)
     {
-        _itemRepository = itemRepository;
+        _persistenceService = persistenceService;
         _libraryManager = libraryManager;
         _mediaEncoder = mediaEncoder;
         _applicationPaths = applicationPaths;
@@ -138,7 +138,7 @@ public partial class AudioNormalizationTask : IScheduledTask
                 {
                     if (toSaveDbItems.Count > 1)
                     {
-                        _itemRepository.SaveItems(toSaveDbItems, cancellationToken);
+                        _persistenceService.SaveItems(toSaveDbItems, cancellationToken);
                         toSaveDbItems.Clear();
                     }
 
@@ -158,7 +158,7 @@ public partial class AudioNormalizationTask : IScheduledTask
 
             if (toSaveDbItems.Count > 1)
             {
-                _itemRepository.SaveItems(toSaveDbItems, cancellationToken);
+                _persistenceService.SaveItems(toSaveDbItems, cancellationToken);
                 toSaveDbItems.Clear();
             }
 
@@ -183,7 +183,7 @@ public partial class AudioNormalizationTask : IScheduledTask
                 {
                     if (toSaveDbItems.Count > 1)
                     {
-                        _itemRepository.SaveItems(toSaveDbItems, cancellationToken);
+                        _persistenceService.SaveItems(toSaveDbItems, cancellationToken);
                         toSaveDbItems.Clear();
                     }
 
@@ -200,7 +200,7 @@ public partial class AudioNormalizationTask : IScheduledTask
 
             if (toSaveDbItems.Count > 1)
             {
-                _itemRepository.SaveItems(toSaveDbItems, cancellationToken);
+                _persistenceService.SaveItems(toSaveDbItems, cancellationToken);
             }
 
             // Update progress
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs
deleted file mode 100644
index 7f68f7701e..0000000000
--- a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs
+++ /dev/null
@@ -1,139 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using MediaBrowser.Controller.Collections;
-using MediaBrowser.Controller.Entities;
-using MediaBrowser.Controller.Entities.Movies;
-using MediaBrowser.Controller.Library;
-using MediaBrowser.Controller.Playlists;
-using MediaBrowser.Controller.Providers;
-using MediaBrowser.Model.Globalization;
-using MediaBrowser.Model.IO;
-using MediaBrowser.Model.Tasks;
-using Microsoft.Extensions.Logging;
-
-namespace Emby.Server.Implementations.ScheduledTasks.Tasks;
-
-/// <summary>
-/// Deletes path references from collections and playlists that no longer exists.
-/// </summary>
-public class CleanupCollectionAndPlaylistPathsTask : IScheduledTask
-{
-    private readonly ILocalizationManager _localization;
-    private readonly ICollectionManager _collectionManager;
-    private readonly IPlaylistManager _playlistManager;
-    private readonly ILogger<CleanupCollectionAndPlaylistPathsTask> _logger;
-    private readonly IProviderManager _providerManager;
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="CleanupCollectionAndPlaylistPathsTask"/> class.
-    /// </summary>
-    /// <param name="localization">Instance of the <see cref="ILocalizationManager"/> interface.</param>
-    /// <param name="collectionManager">Instance of the <see cref="ICollectionManager"/> interface.</param>
-    /// <param name="playlistManager">Instance of the <see cref="IPlaylistManager"/> interface.</param>
-    /// <param name="logger">Instance of the <see cref="ILogger"/> interface.</param>
-    /// <param name="providerManager">Instance of the <see cref="IProviderManager"/> interface.</param>
-    public CleanupCollectionAndPlaylistPathsTask(
-        ILocalizationManager localization,
-        ICollectionManager collectionManager,
-        IPlaylistManager playlistManager,
-        ILogger<CleanupCollectionAndPlaylistPathsTask> logger,
-        IProviderManager providerManager)
-    {
-        _localization = localization;
-        _collectionManager = collectionManager;
-        _playlistManager = playlistManager;
-        _logger = logger;
-        _providerManager = providerManager;
-    }
-
-    /// <inheritdoc />
-    public string Name => _localization.GetLocalizedString("TaskCleanCollectionsAndPlaylists");
-
-    /// <inheritdoc />
-    public string Key => "CleanCollectionsAndPlaylists";
-
-    /// <inheritdoc />
-    public string Description => _localization.GetLocalizedString("TaskCleanCollectionsAndPlaylistsDescription");
-
-    /// <inheritdoc />
-    public string Category => _localization.GetLocalizedString("TasksMaintenanceCategory");
-
-    /// <inheritdoc />
-    public async Task ExecuteAsync(IProgress<double> progress, CancellationToken cancellationToken)
-    {
-        var collectionsFolder = await _collectionManager.GetCollectionsFolder(false).ConfigureAwait(false);
-        if (collectionsFolder is null)
-        {
-            _logger.LogDebug("There is no collections folder to be found");
-        }
-        else
-        {
-            var collections = collectionsFolder.Children.OfType<BoxSet>().ToArray();
-            _logger.LogDebug("Found {CollectionLength} boxsets", collections.Length);
-
-            for (var index = 0; index < collections.Length; index++)
-            {
-                var collection = collections[index];
-                _logger.LogDebug("Checking boxset {CollectionName}", collection.Name);
-
-                await CleanupLinkedChildrenAsync(collection, cancellationToken).ConfigureAwait(false);
-                progress.Report(50D / collections.Length * (index + 1));
-            }
-        }
-
-        var playlistsFolder = _playlistManager.GetPlaylistsFolder();
-        if (playlistsFolder is null)
-        {
-            _logger.LogDebug("There is no playlists folder to be found");
-            return;
-        }
-
-        var playlists = playlistsFolder.Children.OfType<Playlist>().ToArray();
-        _logger.LogDebug("Found {PlaylistLength} playlists", playlists.Length);
-
-        for (var index = 0; index < playlists.Length; index++)
-        {
-            var playlist = playlists[index];
-            _logger.LogDebug("Checking playlist {PlaylistName}", playlist.Name);
-
-            await CleanupLinkedChildrenAsync(playlist, cancellationToken).ConfigureAwait(false);
-            progress.Report(50D / playlists.Length * (index + 1));
-        }
-    }
-
-    private async Task CleanupLinkedChildrenAsync<T>(T folder, CancellationToken cancellationToken)
-        where T : Folder
-    {
-        List<LinkedChild>? itemsToRemove = null;
-        foreach (var linkedChild in folder.LinkedChildren)
-        {
-            var path = linkedChild.Path;
-            if (!File.Exists(path) && !Directory.Exists(path))
-            {
-                _logger.LogInformation("Item in {FolderName} cannot be found at {ItemPath}", folder.Name, path);
-                (itemsToRemove ??= new List<LinkedChild>()).Add(linkedChild);
-            }
-        }
-
-        if (itemsToRemove is not null)
-        {
-            _logger.LogDebug("Updating {FolderName}", folder.Name);
-            folder.LinkedChildren = folder.LinkedChildren.Except(itemsToRemove).ToArray();
-            await _providerManager.SaveMetadataAsync(folder, ItemUpdateType.MetadataEdit).ConfigureAwait(false);
-            await folder.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, cancellationToken).ConfigureAwait(false);
-        }
-    }
-
-    /// <inheritdoc />
-    public IEnumerable<TaskTriggerInfo> GetDefaultTriggers()
-    {
-        yield return new TaskTriggerInfo
-        {
-            Type = TaskTriggerInfoType.StartupTrigger,
-        };
-    }
-}
diff --git a/Emby.Server.Implementations/Session/SessionManager.cs b/Emby.Server.Implementations/Session/SessionManager.cs
index d4d0f4537b..e2ddf86c7a 100644
--- a/Emby.Server.Implementations/Session/SessionManager.cs
+++ b/Emby.Server.Implementations/Session/SessionManager.cs
@@ -1828,7 +1828,6 @@ namespace Emby.Server.Implementations.Session
                 fields.Remove(ItemFields.Settings);
                 fields.Remove(ItemFields.SortName);
                 fields.Remove(ItemFields.Tags);
-                fields.Remove(ItemFields.ExtraIds);
 
                 dtoOptions.Fields = fields.ToArray();
 
diff --git a/Emby.Server.Implementations/TV/TVSeriesManager.cs b/Emby.Server.Implementations/TV/TVSeriesManager.cs
index cd98dbe86e..535dc01a31 100644
--- a/Emby.Server.Implementations/TV/TVSeriesManager.cs
+++ b/Emby.Server.Implementations/TV/TVSeriesManager.cs
@@ -47,7 +47,7 @@ namespace Emby.Server.Implementations.TV
 
             if (!string.IsNullOrEmpty(presentationUniqueKey))
             {
-                return GetResult(GetNextUpEpisodes(query, user, new[] { presentationUniqueKey }, options), query);
+                return GetNextUpBatched(query, user, [presentationUniqueKey], options);
             }
 
             BaseItem[] parents;
@@ -58,11 +58,11 @@ namespace Emby.Server.Implementations.TV
 
                 if (parent is not null)
                 {
-                    parents = new[] { parent };
+                    parents = [parent];
                 }
                 else
                 {
-                    parents = Array.Empty<BaseItem>();
+                    parents = [];
                 }
             }
             else
@@ -93,7 +93,7 @@ namespace Emby.Server.Implementations.TV
 
             if (!string.IsNullOrEmpty(presentationUniqueKey))
             {
-                return GetResult(GetNextUpEpisodes(request, user, [presentationUniqueKey], options), request);
+                return GetNextUpBatched(request, user, [presentationUniqueKey], options);
             }
 
             if (limit.HasValue)
@@ -103,151 +103,143 @@ namespace Emby.Server.Implementations.TV
 
             var nextUpSeriesKeys = _libraryManager.GetNextUpSeriesKeys(new InternalItemsQuery(user) { Limit = limit }, parentsFolders, request.NextUpDateCutoff);
 
-            var episodes = GetNextUpEpisodes(request, user, nextUpSeriesKeys, options);
-
-            return GetResult(episodes, request);
+            return GetNextUpBatched(request, user, nextUpSeriesKeys, options);
         }
 
-        private IEnumerable<Episode> GetNextUpEpisodes(NextUpQuery request, User user, IReadOnlyList<string> seriesKeys, DtoOptions dtoOptions)
+        private QueryResult<BaseItem> GetNextUpBatched(NextUpQuery request, User user, IReadOnlyList<string> seriesKeys, DtoOptions dtoOptions)
         {
-            var allNextUp = seriesKeys.Select(i => GetNextUp(i, user, dtoOptions, request.EnableResumable, false));
-
-            if (request.EnableRewatching)
+            if (seriesKeys.Count == 0)
             {
-                allNextUp = allNextUp
-                    .Concat(seriesKeys.Select(i => GetNextUp(i, user, dtoOptions, false, true)))
-                    .OrderByDescending(i => i.LastWatchedDate);
+                return new QueryResult<BaseItem>();
             }
 
-            return allNextUp
-                .Select(i => i.GetEpisodeFunction())
-                .Where(i => i is not null)!;
-        }
-
-        private static string GetUniqueSeriesKey(Series series)
-        {
-            return series.GetPresentationUniqueKey();
-        }
+            var includeSpecials = _configurationManager.Configuration.DisplaySpecialsWithinSeasons;
+            var includeRewatching = request.EnableRewatching;
 
-        /// <summary>
-        /// Gets the next up.
-        /// </summary>
-        /// <returns>Task{Episode}.</returns>
-        private (DateTime LastWatchedDate, Func<Episode?> GetEpisodeFunction) GetNextUp(string seriesKey, User user, DtoOptions dtoOptions, bool includeResumable, bool includePlayed)
-        {
-            var lastQuery = new InternalItemsQuery(user)
+            var query = new InternalItemsQuery(user)
             {
-                AncestorWithPresentationUniqueKey = null,
-                SeriesPresentationUniqueKey = seriesKey,
-                IncludeItemTypes = [BaseItemKind.Episode],
-                IsPlayed = true,
-                Limit = 1,
-                ParentIndexNumberNotEquals = 0,
-                DtoOptions = new DtoOptions
-                {
-                    Fields = [ItemFields.SortName],
-                    EnableImages = false
-                }
+                DtoOptions = dtoOptions
             };
 
-            // If including played results, sort first by date played and then by season and episode numbers
-            lastQuery.OrderBy = includePlayed
-                ? new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.ParentIndexNumber, SortOrder.Descending), (ItemSortBy.IndexNumber, SortOrder.Descending) }
-                : new[] { (ItemSortBy.ParentIndexNumber, SortOrder.Descending), (ItemSortBy.IndexNumber, SortOrder.Descending) };
+            var batchResult = _libraryManager.GetNextUpEpisodesBatch(query, seriesKeys, includeSpecials, includeRewatching);
 
-            var lastWatchedEpisode = _libraryManager.GetItemList(lastQuery).Cast<Episode>().FirstOrDefault();
+            var nextUpList = new List<(DateTime LastWatchedDate, Episode Episode)>();
 
-            Episode? GetEpisode()
+            foreach (var seriesKey in seriesKeys)
             {
-                var nextQuery = new InternalItemsQuery(user)
+                if (!batchResult.TryGetValue(seriesKey, out var result))
                 {
-                    AncestorWithPresentationUniqueKey = null,
-                    SeriesPresentationUniqueKey = seriesKey,
-                    IncludeItemTypes = [BaseItemKind.Episode],
-                    OrderBy = [(ItemSortBy.ParentIndexNumber, SortOrder.Ascending), (ItemSortBy.IndexNumber, SortOrder.Ascending)],
-                    Limit = 1,
-                    IsPlayed = includePlayed,
-                    IsVirtualItem = false,
-                    ParentIndexNumberNotEquals = 0,
-                    DtoOptions = dtoOptions
-                };
-
-                // Locate the next up episode based on the last watched episode's season and episode number
-                var lastWatchedParentIndexNumber = lastWatchedEpisode?.ParentIndexNumber;
-                var lastWatchedIndexNumber = lastWatchedEpisode?.IndexNumberEnd ?? lastWatchedEpisode?.IndexNumber;
-                if (lastWatchedParentIndexNumber.HasValue && lastWatchedIndexNumber.HasValue)
-                {
-                    nextQuery.MinParentAndIndexNumber = (lastWatchedParentIndexNumber.Value, lastWatchedIndexNumber.Value + 1);
+                    continue;
                 }
 
-                var nextEpisode = _libraryManager.GetItemList(nextQuery).Cast<Episode>().FirstOrDefault();
+                var nextEpisode = DetermineNextEpisode(result, user, includeSpecials, request.EnableResumable, false);
+
+                if (nextEpisode is not null)
+                {
+                    DateTime lastWatchedDate = DateTime.MinValue;
+                    if (result.LastWatched is not null)
+                    {
+                        var userData = _userDataManager.GetUserData(user, result.LastWatched);
+                        lastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+                    }
+
+                    nextUpList.Add((lastWatchedDate, nextEpisode));
+                }
 
-                if (_configurationManager.Configuration.DisplaySpecialsWithinSeasons)
+                if (includeRewatching)
                 {
-                    var consideredEpisodes = _libraryManager.GetItemList(new InternalItemsQuery(user)
+                    var nextPlayedEpisode = DetermineNextEpisodeForRewatching(result, user, includeSpecials);
+
+                    if (nextPlayedEpisode is not null)
                     {
-                        AncestorWithPresentationUniqueKey = null,
-                        SeriesPresentationUniqueKey = seriesKey,
-                        ParentIndexNumber = 0,
-                        IncludeItemTypes = [BaseItemKind.Episode],
-                        IsPlayed = includePlayed,
-                        IsVirtualItem = false,
-                        DtoOptions = dtoOptions
-                    })
+                        DateTime rewatchLastWatchedDate = DateTime.MinValue;
+                        if (result.LastWatchedForRewatching is not null)
+                        {
+                            var userData = _userDataManager.GetUserData(user, result.LastWatchedForRewatching);
+                            rewatchLastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+                        }
+
+                        nextUpList.Add((rewatchLastWatchedDate, nextPlayedEpisode));
+                    }
+                }
+            }
+
+            var sortedEpisodes = nextUpList
+                .OrderByDescending(x => x.LastWatchedDate)
+                .Select(x => (BaseItem)x.Episode);
+
+            return GetResult(sortedEpisodes, request);
+        }
+
+        private Episode? DetermineNextEpisode(
+            MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult result,
+            User user,
+            bool includeSpecials,
+            bool includeResumable,
+            bool includePlayed)
+        {
+            var nextEpisode = (includePlayed ? result.NextPlayedForRewatching : result.NextUp) as Episode;
+            var lastWatchedEpisode = (includePlayed ? result.LastWatchedForRewatching : result.LastWatched) as Episode;
+
+            if (includeSpecials && result.Specials?.Count > 0)
+            {
+                var consideredEpisodes = result.Specials
                     .Cast<Episode>()
                     .Where(episode => episode.AirsBeforeSeasonNumber is not null || episode.AirsAfterSeasonNumber is not null)
                     .ToList();
 
-                    if (lastWatchedEpisode is not null)
-                    {
-                        // Last watched episode is added, because there could be specials that aired before the last watched episode
-                        consideredEpisodes.Add(lastWatchedEpisode);
-                    }
+                if (lastWatchedEpisode is not null)
+                {
+                    consideredEpisodes.Add(lastWatchedEpisode);
+                }
 
-                    if (nextEpisode is not null)
-                    {
-                        consideredEpisodes.Add(nextEpisode);
-                    }
+                if (nextEpisode is not null)
+                {
+                    consideredEpisodes.Add(nextEpisode);
+                }
 
-                    var sortedConsideredEpisodes = _libraryManager.Sort(consideredEpisodes, user, [(ItemSortBy.AiredEpisodeOrder, SortOrder.Ascending)])
+                if (consideredEpisodes.Count > 0)
+                {
+                    var sortedEpisodes = _libraryManager.Sort(consideredEpisodes, user, [(ItemSortBy.AiredEpisodeOrder, SortOrder.Ascending)])
                         .Cast<Episode>();
+
                     if (lastWatchedEpisode is not null)
                     {
-                        sortedConsideredEpisodes = sortedConsideredEpisodes.SkipWhile(episode => !episode.Id.Equals(lastWatchedEpisode.Id)).Skip(1);
+                        sortedEpisodes = sortedEpisodes.SkipWhile(episode => !episode.Id.Equals(lastWatchedEpisode.Id)).Skip(1);
                     }
 
-                    nextEpisode = sortedConsideredEpisodes.FirstOrDefault();
-                }
-
-                if (nextEpisode is not null && !includeResumable)
-                {
-                    var userData = _userDataManager.GetUserData(user, nextEpisode);
-
-                    if (userData?.PlaybackPositionTicks > 0)
+                    if (!includePlayed)
                     {
-                        return null;
+                        sortedEpisodes = sortedEpisodes.Where(episode => _userDataManager.GetUserData(user, episode) is not { Played: true });
                     }
-                }
 
-                return nextEpisode;
+                    nextEpisode = sortedEpisodes.FirstOrDefault();
+                }
             }
 
-            if (lastWatchedEpisode is not null)
+            if (nextEpisode is not null && !includeResumable)
             {
-                var userData = _userDataManager.GetUserData(user, lastWatchedEpisode);
-
-                if (userData is null)
+                var userData = _userDataManager.GetUserData(user, nextEpisode);
+                if (userData?.PlaybackPositionTicks > 0)
                 {
-                    return (DateTime.MinValue, GetEpisode);
+                    return null;
                 }
+            }
 
-                var lastWatchedDate = userData.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+            return nextEpisode;
+        }
 
-                return (lastWatchedDate, GetEpisode);
-            }
+        private Episode? DetermineNextEpisodeForRewatching(
+            MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult result,
+            User user,
+            bool includeSpecials)
+        {
+            return DetermineNextEpisode(result, user, includeSpecials, includeResumable: false, includePlayed: true);
+        }
 
-            // Return the first episode
-            return (DateTime.MinValue, GetEpisode);
+        private static string GetUniqueSeriesKey(Series series)
+        {
+            return series.GetPresentationUniqueKey();
         }
 
         private static QueryResult<BaseItem> GetResult(IEnumerable<BaseItem> items, NextUpQuery query)