Merge branch 'master' into segment-deletion

1 files changed, 144 insertions, 150 deletions

diff --git a/Emby.Server.Implementations/Library/LibraryManager.cs b/Emby.Server.Implementations/Library/LibraryManager.cs
index cef82ebbc..ea45bf0ba 100644
--- a/Emby.Server.Implementations/Library/LibraryManager.cs
+++ b/Emby.Server.Implementations/Library/LibraryManager.cs
@@ -113,6 +113,7 @@ namespace Emby.Server.Implementations.Library
         /// <param name="imageProcessor">The image processor.</param>
         /// <param name="memoryCache">The memory cache.</param>
         /// <param name="namingOptions">The naming options.</param>
+        /// <param name="directoryService">The directory service.</param>
         public LibraryManager(
             IServerApplicationHost appHost,
             ILoggerFactory loggerFactory,
@@ -128,7 +129,8 @@ namespace Emby.Server.Implementations.Library
             IItemRepository itemRepository,
             IImageProcessor imageProcessor,
             IMemoryCache memoryCache,
-            NamingOptions namingOptions)
+            NamingOptions namingOptions,
+            IDirectoryService directoryService)
         {
             _appHost = appHost;
             _logger = loggerFactory.CreateLogger<LibraryManager>();
@@ -146,7 +148,7 @@ namespace Emby.Server.Implementations.Library
             _memoryCache = memoryCache;
             _namingOptions = namingOptions;
 
-            _extraResolver = new ExtraResolver(loggerFactory.CreateLogger<ExtraResolver>(), namingOptions);
+            _extraResolver = new ExtraResolver(loggerFactory.CreateLogger<ExtraResolver>(), namingOptions, directoryService);
 
             _configurationManager.ConfigurationUpdated += ConfigurationUpdated;
 
@@ -176,7 +178,7 @@ namespace Emby.Server.Implementations.Library
         {
             get
             {
-                if (_rootFolder == null)
+                if (_rootFolder is null)
                 {
                     lock (_rootFolderSyncLock)
                     {
@@ -356,8 +358,8 @@ namespace Emby.Server.Implementations.Library
             }
 
             var children = item.IsFolder
-                ? ((Folder)item).GetRecursiveChildren(false).ToList()
-                : new List<BaseItem>();
+                ? ((Folder)item).GetRecursiveChildren(false)
+                : Enumerable.Empty<BaseItem>();
 
             foreach (var metadataPath in GetMetadataPaths(item, children))
             {
@@ -465,9 +467,9 @@ namespace Emby.Server.Implementations.Library
         private BaseItem ResolveItem(ItemResolveArgs args, IItemResolver[] resolvers)
         {
             var item = (resolvers ?? EntityResolvers).Select(r => Resolve(args, r))
-                .FirstOrDefault(i => i != null);
+                .FirstOrDefault(i => i is not null);
 
-            if (item != null)
+            if (item is not null)
             {
                 ResolverHelper.SetInitialItemValues(item, args, _fileSystem, this);
             }
@@ -495,11 +497,7 @@ namespace Emby.Server.Implementations.Library
 
         private Guid GetNewItemIdInternal(string key, Type type, bool forceCaseInsensitive)
         {
-            if (string.IsNullOrEmpty(key))
-            {
-                throw new ArgumentNullException(nameof(key));
-            }
-
+            ArgumentException.ThrowIfNullOrEmpty(key);
             ArgumentNullException.ThrowIfNull(type);
 
             string programDataPath = _configurationManager.ApplicationPaths.ProgramDataPath;
@@ -536,12 +534,12 @@ namespace Emby.Server.Implementations.Library
 
             var fullPath = fileInfo.FullName;
 
-            if (string.IsNullOrEmpty(collectionType) && parent != null)
+            if (string.IsNullOrEmpty(collectionType) && parent is not null)
             {
                 collectionType = GetContentTypeOverride(fullPath, true);
             }
 
-            var args = new ItemResolveArgs(_configurationManager.ApplicationPaths, directoryService)
+            var args = new ItemResolveArgs(_configurationManager.ApplicationPaths, this)
             {
                 Parent = parent,
                 FileInfo = fileInfo,
@@ -572,7 +570,7 @@ namespace Emby.Server.Implementations.Library
                 }
                 catch (Exception ex)
                 {
-                    if (parent != null && parent.IsPhysicalRoot)
+                    if (parent is not null && parent.IsPhysicalRoot)
                     {
                         _logger.LogError(ex, "Error in GetFilteredFileSystemEntries isPhysicalRoot: {0} IsVf: {1}", isPhysicalRoot, isVf);
 
@@ -654,9 +652,9 @@ namespace Emby.Server.Implementations.Library
         {
             var fileList = files.Where(i => !IgnoreFile(i, parent)).ToList();
 
-            if (parent != null)
+            if (parent is not null)
             {
-                var multiItemResolvers = resolvers == null ? MultiItemResolvers : resolvers.OfType<IMultiItemResolver>().ToArray();
+                var multiItemResolvers = resolvers is null ? MultiItemResolvers : resolvers.OfType<IMultiItemResolver>().ToArray();
 
                 foreach (var resolver in multiItemResolvers)
                 {
@@ -697,7 +695,7 @@ namespace Emby.Server.Implementations.Library
                     _logger.LogError(ex, "Error resolving path {Path}", file.FullName);
                 }
 
-                if (result != null)
+                if (result is not null)
                 {
                     yield return result;
                 }
@@ -750,7 +748,7 @@ namespace Emby.Server.Implementations.Library
 
             var dbItem = GetItemById(folder.Id) as BasePluginFolder;
 
-            if (dbItem != null && string.Equals(dbItem.Path, folder.Path, StringComparison.OrdinalIgnoreCase))
+            if (dbItem is not null && string.Equals(dbItem.Path, folder.Path, StringComparison.OrdinalIgnoreCase))
             {
                 folder = dbItem;
             }
@@ -770,11 +768,11 @@ namespace Emby.Server.Implementations.Library
 
         public Folder GetUserRootFolder()
         {
-            if (_userRootFolder == null)
+            if (_userRootFolder is null)
             {
                 lock (_userRootFolderSyncLock)
                 {
-                    if (_userRootFolder == null)
+                    if (_userRootFolder is null)
                     {
                         var userRootPath = _configurationManager.ApplicationPaths.DefaultUserViewsPath;
 
@@ -792,7 +790,7 @@ namespace Emby.Server.Implementations.Library
                             _logger.LogError(ex, "Error creating UserRootFolder {Path}", newItemId);
                         }
 
-                        if (tmpItem == null)
+                        if (tmpItem is null)
                         {
                             _logger.LogDebug("Creating new userRootFolder with DeepCopy");
                             tmpItem = ((Folder)ResolvePath(_fileSystem.GetDirectoryInfo(userRootPath))).DeepCopy<Folder, UserRootFolder>();
@@ -818,10 +816,7 @@ namespace Emby.Server.Implementations.Library
         {
             // If this returns multiple items it could be tricky figuring out which one is correct.
             // In most cases, the newest one will be and the others obsolete but not yet cleaned up
-            if (string.IsNullOrEmpty(path))
-            {
-                throw new ArgumentNullException(nameof(path));
-            }
+            ArgumentException.ThrowIfNullOrEmpty(path);
 
             var query = new InternalItemsQuery
             {
@@ -952,7 +947,7 @@ namespace Emby.Server.Implementations.Library
                 .Cast<T>()
                 .FirstOrDefault();
 
-                if (existing != null)
+                if (existing is not null)
                 {
                     return existing;
                 }
@@ -961,7 +956,7 @@ namespace Emby.Server.Implementations.Library
             var path = getPathFn(name);
             var id = GetItemByNameId<T>(path);
             var item = GetItemById(id) as T;
-            if (item == null)
+            if (item is null)
             {
                 item = new T
                 {
@@ -1161,7 +1156,7 @@ namespace Emby.Server.Implementations.Library
                 .ToList();
         }
 
-        private VirtualFolderInfo GetVirtualFolderInfo(string dir, List<BaseItem> allCollectionFolders, Dictionary<Guid, Guid> refreshQueue)
+        private VirtualFolderInfo GetVirtualFolderInfo(string dir, List<BaseItem> allCollectionFolders, HashSet<Guid> refreshQueue)
         {
             var info = new VirtualFolderInfo
             {
@@ -1181,30 +1176,30 @@ namespace Emby.Server.Implementations.Library
                             return null;
                         }
                     })
-                    .Where(i => i != null)
-                    .OrderBy(i => i)
+                    .Where(i => i is not null)
+                    .Order()
                     .ToArray(),
 
                 CollectionType = GetCollectionType(dir)
             };
 
             var libraryFolder = allCollectionFolders.FirstOrDefault(i => string.Equals(i.Path, dir, StringComparison.OrdinalIgnoreCase));
-
-            if (libraryFolder != null && libraryFolder.HasImage(ImageType.Primary))
+            if (libraryFolder is not null)
             {
-                info.PrimaryImageItemId = libraryFolder.Id.ToString("N", CultureInfo.InvariantCulture);
-            }
+                var libraryFolderId = libraryFolder.Id.ToString("N", CultureInfo.InvariantCulture);
+                info.ItemId = libraryFolderId;
+                if (libraryFolder.HasImage(ImageType.Primary))
+                {
+                    info.PrimaryImageItemId = libraryFolderId;
+                }
 
-            if (libraryFolder != null)
-            {
-                info.ItemId = libraryFolder.Id.ToString("N", CultureInfo.InvariantCulture);
                 info.LibraryOptions = GetLibraryOptions(libraryFolder);
 
-                if (refreshQueue != null)
+                if (refreshQueue is not null)
                 {
                     info.RefreshProgress = libraryFolder.GetRefreshProgress();
 
-                    info.RefreshStatus = info.RefreshProgress.HasValue ? "Active" : refreshQueue.ContainsKey(libraryFolder.Id) ? "Queued" : "Idle";
+                    info.RefreshStatus = info.RefreshProgress.HasValue ? "Active" : refreshQueue.Contains(libraryFolder.Id) ? "Queued" : "Idle";
                 }
             }
 
@@ -1245,7 +1240,7 @@ namespace Emby.Server.Implementations.Library
 
             item = RetrieveItem(id);
 
-            if (item != null)
+            if (item is not null)
             {
                 RegisterItem(item);
             }
@@ -1258,18 +1253,25 @@ namespace Emby.Server.Implementations.Library
             if (query.Recursive && !query.ParentId.Equals(default))
             {
                 var parent = GetItemById(query.ParentId);
-                if (parent != null)
+                if (parent is not null)
                 {
-                    SetTopParentIdsOrAncestors(query, new List<BaseItem> { parent });
+                    SetTopParentIdsOrAncestors(query, new[] { parent });
                 }
             }
 
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User, allowExternalContent);
             }
 
-            return _itemRepository.GetItemList(query);
+            var itemList = _itemRepository.GetItemList(query);
+            var user = query.User;
+            if (user is not null)
+            {
+                return itemList.Where(i => i.IsVisible(user)).ToList();
+            }
+
+            return itemList;
         }
 
         public List<BaseItem> GetItemList(InternalItemsQuery query)
@@ -1282,13 +1284,13 @@ namespace Emby.Server.Implementations.Library
             if (query.Recursive && !query.ParentId.Equals(default))
             {
                 var parent = GetItemById(query.ParentId);
-                if (parent != null)
+                if (parent is not null)
                 {
-                    SetTopParentIdsOrAncestors(query, new List<BaseItem> { parent });
+                    SetTopParentIdsOrAncestors(query, new[] { parent });
                 }
             }
 
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1302,7 +1304,7 @@ namespace Emby.Server.Implementations.Library
 
             if (query.AncestorIds.Length == 0 && query.TopParentIds.Length == 0)
             {
-                if (query.User != null)
+                if (query.User is not null)
                 {
                     AddUserToQuery(query, query.User);
                 }
@@ -1313,7 +1315,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<BaseItem> QueryItems(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1331,7 +1333,7 @@ namespace Emby.Server.Implementations.Library
 
         public List<Guid> GetItemIds(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1341,7 +1343,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetStudios(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1352,7 +1354,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetGenres(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1363,7 +1365,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetMusicGenres(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1374,7 +1376,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetAllArtists(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1385,7 +1387,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetArtists(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1426,7 +1428,7 @@ namespace Emby.Server.Implementations.Library
 
         public QueryResult<(BaseItem Item, ItemCounts ItemCounts)> GetAlbumArtists(InternalItemsQuery query)
         {
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1440,13 +1442,13 @@ namespace Emby.Server.Implementations.Library
             if (query.Recursive && !query.ParentId.Equals(default))
             {
                 var parent = GetItemById(query.ParentId);
-                if (parent != null)
+                if (parent is not null)
                 {
-                    SetTopParentIdsOrAncestors(query, new List<BaseItem> { parent });
+                    SetTopParentIdsOrAncestors(query, new[] { parent });
                 }
             }
 
-            if (query.User != null)
+            if (query.User is not null)
             {
                 AddUserToQuery(query, query.User);
             }
@@ -1462,7 +1464,7 @@ namespace Emby.Server.Implementations.Library
                 _itemRepository.GetItemList(query));
         }
 
-        private void SetTopParentIdsOrAncestors(InternalItemsQuery query, List<BaseItem> parents)
+        private void SetTopParentIdsOrAncestors(InternalItemsQuery query, IReadOnlyCollection<BaseItem> parents)
         {
             if (parents.All(i => i is ICollectionFolder || i is UserView))
             {
@@ -1508,6 +1510,12 @@ namespace Emby.Server.Implementations.Library
                 });
 
                 query.TopParentIds = userViews.SelectMany(i => GetTopParentIdsForQuery(i, user)).ToArray();
+
+                // Prevent searching in all libraries due to empty filter
+                if (query.TopParentIds.Length == 0)
+                {
+                    query.TopParentIds = new[] { Guid.NewGuid() };
+                }
             }
         }
 
@@ -1524,7 +1532,7 @@ namespace Emby.Server.Implementations.Library
                 if (!view.DisplayParentId.Equals(default))
                 {
                     var displayParent = GetItemById(view.DisplayParentId);
-                    if (displayParent != null)
+                    if (displayParent is not null)
                     {
                         return GetTopParentIdsForQuery(displayParent, user);
                     }
@@ -1535,7 +1543,7 @@ namespace Emby.Server.Implementations.Library
                 if (!view.ParentId.Equals(default))
                 {
                     var displayParent = GetItemById(view.ParentId);
-                    if (displayParent != null)
+                    if (displayParent is not null)
                     {
                         return GetTopParentIdsForQuery(displayParent, user);
                     }
@@ -1544,7 +1552,7 @@ namespace Emby.Server.Implementations.Library
                 }
 
                 // Handle grouping
-                if (user != null && !string.IsNullOrEmpty(view.ViewType) && UserView.IsEligibleForGrouping(view.ViewType)
+                if (user is not null && !string.IsNullOrEmpty(view.ViewType) && UserView.IsEligibleForGrouping(view.ViewType)
                     && user.GetPreference(PreferenceKind.GroupedFolders).Length > 0)
                 {
                     return GetUserRootFolder()
@@ -1564,7 +1572,7 @@ namespace Emby.Server.Implementations.Library
             }
 
             var topParent = item.GetTopParent();
-            if (topParent != null)
+            if (topParent is not null)
             {
                 return new[] { topParent.Id };
             }
@@ -1589,7 +1597,7 @@ namespace Emby.Server.Implementations.Library
             return items
                 .SelectMany(i => i.ToArray())
                 .Select(ResolveIntro)
-                .Where(i => i != null);
+                .Where(i => i is not null);
         }
 
         /// <summary>
@@ -1609,7 +1617,7 @@ namespace Emby.Server.Implementations.Library
             {
                 _logger.LogError(ex, "Error getting intros");
 
-                return new List<IntroInfo>();
+                return Enumerable.Empty<IntroInfo>();
             }
         }
 
@@ -1627,7 +1635,7 @@ namespace Emby.Server.Implementations.Library
                 // Get an existing item by Id
                 video = GetItemById(info.ItemId.Value) as Video;
 
-                if (video == null)
+                if (video is null)
                 {
                     _logger.LogError("Unable to locate item with Id {ID}.", info.ItemId.Value);
                 }
@@ -1639,7 +1647,7 @@ namespace Emby.Server.Implementations.Library
                     // Try to resolve the path into a video
                     video = ResolvePath(_fileSystem.GetFileSystemInfo(info.Path)) as Video;
 
-                    if (video == null)
+                    if (video is null)
                     {
                         _logger.LogError("Intro resolver returned null for {Path}.", info.Path);
                     }
@@ -1648,7 +1656,7 @@ namespace Emby.Server.Implementations.Library
                         // Pull the saved db item that will include metadata
                         var dbItem = GetItemById(video.Id) as Video;
 
-                        if (dbItem != null)
+                        if (dbItem is not null)
                         {
                             video = dbItem;
                         }
@@ -1685,7 +1693,7 @@ namespace Emby.Server.Implementations.Library
 
             IOrderedEnumerable<BaseItem> orderedItems = null;
 
-            foreach (var orderBy in sortBy.Select(o => GetComparer(o, user)).Where(c => c != null))
+            foreach (var orderBy in sortBy.Select(o => GetComparer(o, user)).Where(c => c is not null))
             {
                 if (isFirst)
                 {
@@ -1711,7 +1719,7 @@ namespace Emby.Server.Implementations.Library
             foreach (var (name, sortOrder) in orderBy)
             {
                 var comparer = GetComparer(name, user);
-                if (comparer == null)
+                if (comparer is null)
                 {
                     continue;
                 }
@@ -1781,7 +1789,7 @@ namespace Emby.Server.Implementations.Library
                 RegisterItem(item);
             }
 
-            if (ItemAdded != null)
+            if (ItemAdded is not null)
             {
                 foreach (var item in items)
                 {
@@ -1811,7 +1819,7 @@ namespace Emby.Server.Implementations.Library
 
         private bool ImageNeedsRefresh(ItemImageInfo image)
         {
-            if (image.Path != null && image.IsLocalFile)
+            if (image.Path is not null && image.IsLocalFile)
             {
                 if (image.Width == 0 || image.Height == 0 || string.IsNullOrEmpty(image.BlurHash))
                 {
@@ -1829,7 +1837,7 @@ namespace Emby.Server.Implementations.Library
                 }
             }
 
-            return image.Path != null && !image.IsLocalFile;
+            return image.Path is not null && !image.IsLocalFile;
         }
 
         /// <inheritdoc />
@@ -1838,7 +1846,7 @@ namespace Emby.Server.Implementations.Library
             ArgumentNullException.ThrowIfNull(item);
 
             var outdated = forceUpdate
-                ? item.ImageInfos.Where(i => i.Path != null).ToArray()
+                ? item.ImageInfos.Where(i => i.Path is not null).ToArray()
                 : item.ImageInfos.Where(ImageNeedsRefresh).ToArray();
             // Skip image processing if current or live tv source
             if (outdated.Length == 0 || item.SourceType != SourceType.Library)
@@ -1884,7 +1892,7 @@ namespace Emby.Server.Implementations.Library
                 catch (Exception ex)
                 {
                     _logger.LogError(ex, "Cannot get image dimensions for {ImagePath}", image.Path);
-                    size = new ImageDimensions(0, 0);
+                    size = default;
                     image.Width = 0;
                     image.Height = 0;
                 }
@@ -1923,7 +1931,7 @@ namespace Emby.Server.Implementations.Library
 
             _itemRepository.SaveItems(items, cancellationToken);
 
-            if (ItemUpdated != null)
+            if (ItemUpdated is not null)
             {
                 foreach (var item in items)
                 {
@@ -1975,7 +1983,7 @@ namespace Emby.Server.Implementations.Library
         /// <param name="parent">The parent item.</param>
         public void ReportItemRemoved(BaseItem item, BaseItem parent)
         {
-            if (ItemRemoved != null)
+            if (ItemRemoved is not null)
             {
                 try
                 {
@@ -2006,41 +2014,38 @@ namespace Emby.Server.Implementations.Library
 
         public List<Folder> GetCollectionFolders(BaseItem item)
         {
-            while (item != null)
+            return GetCollectionFolders(item, GetUserRootFolder().Children.OfType<Folder>());
+        }
+
+        public List<Folder> GetCollectionFolders(BaseItem item, IEnumerable<Folder> allUserRootChildren)
+        {
+            while (item is not null)
             {
                 var parent = item.GetParent();
 
-                if (parent == null || parent is AggregateFolder)
+                if (parent is AggregateFolder)
                 {
                     break;
                 }
 
-                item = parent;
-            }
-
-            if (item == null)
-            {
-                return new List<Folder>();
-            }
-
-            return GetCollectionFoldersInternal(item, GetUserRootFolder().Children.OfType<Folder>());
-        }
+                if (parent is null)
+                {
+                    var owner = item.GetOwner();
 
-        public List<Folder> GetCollectionFolders(BaseItem item, List<Folder> allUserRootChildren)
-        {
-            while (item != null)
-            {
-                var parent = item.GetParent();
+                    if (owner is null)
+                    {
+                        break;
+                    }
 
-                if (parent == null || parent is AggregateFolder)
+                    item = owner;
+                }
+                else
                 {
-                    break;
+                    item = parent;
                 }
-
-                item = parent;
             }
 
-            if (item == null)
+            if (item is null)
             {
                 return new List<Folder>();
             }
@@ -2064,7 +2069,7 @@ namespace Emby.Server.Implementations.Library
                     .Find(folder => folder is CollectionFolder) as CollectionFolder;
             }
 
-            return collectionFolder == null ? new LibraryOptions() : collectionFolder.GetLibraryOptions();
+            return collectionFolder is null ? new LibraryOptions() : collectionFolder.GetLibraryOptions();
         }
 
         public string GetContentType(BaseItem item)
@@ -2129,7 +2134,7 @@ namespace Emby.Server.Implementations.Library
 
         private string GetTopFolderContentType(BaseItem item)
         {
-            if (item == null)
+            if (item is null)
             {
                 return null;
             }
@@ -2137,7 +2142,7 @@ namespace Emby.Server.Implementations.Library
             while (!item.ParentId.Equals(default))
             {
                 var parent = item.GetParent();
-                if (parent == null || parent is AggregateFolder)
+                if (parent is null || parent is AggregateFolder)
                 {
                     break;
                 }
@@ -2177,7 +2182,7 @@ namespace Emby.Server.Implementations.Library
 
             var refresh = false;
 
-            if (item == null || !string.Equals(item.Path, path, StringComparison.OrdinalIgnoreCase))
+            if (item is null || !string.Equals(item.Path, path, StringComparison.OrdinalIgnoreCase))
             {
                 Directory.CreateDirectory(path);
 
@@ -2225,7 +2230,7 @@ namespace Emby.Server.Implementations.Library
 
             var isNew = false;
 
-            if (item == null)
+            if (item is null)
             {
                 Directory.CreateDirectory(path);
 
@@ -2251,7 +2256,7 @@ namespace Emby.Server.Implementations.Library
             if (!refresh && !item.DisplayParentId.Equals(default))
             {
                 var displayParent = GetItemById(item.DisplayParentId);
-                refresh = displayParent != null && displayParent.DateLastSaved > item.DateLastRefreshed;
+                refresh = displayParent is not null && displayParent.DateLastSaved > item.DateLastRefreshed;
             }
 
             if (refresh)
@@ -2289,7 +2294,7 @@ namespace Emby.Server.Implementations.Library
 
             var isNew = false;
 
-            if (item == null)
+            if (item is null)
             {
                 Directory.CreateDirectory(path);
 
@@ -2315,7 +2320,7 @@ namespace Emby.Server.Implementations.Library
             if (!refresh && !item.DisplayParentId.Equals(default))
             {
                 var displayParent = GetItemById(item.DisplayParentId);
-                refresh = displayParent != null && displayParent.DateLastSaved > item.DateLastRefreshed;
+                refresh = displayParent is not null && displayParent.DateLastSaved > item.DateLastRefreshed;
             }
 
             if (refresh)
@@ -2340,10 +2345,7 @@ namespace Emby.Server.Implementations.Library
             string sortName,
             string uniqueId)
         {
-            if (string.IsNullOrEmpty(name))
-            {
-                throw new ArgumentNullException(nameof(name));
-            }
+            ArgumentException.ThrowIfNullOrEmpty(name);
 
             var parentIdString = parentId.Equals(default)
                 ? null
@@ -2362,7 +2364,7 @@ namespace Emby.Server.Implementations.Library
 
             var isNew = false;
 
-            if (item == null)
+            if (item is null)
             {
                 Directory.CreateDirectory(path);
 
@@ -2394,7 +2396,7 @@ namespace Emby.Server.Implementations.Library
             if (!refresh && !item.DisplayParentId.Equals(default))
             {
                 var displayParent = GetItemById(item.DisplayParentId);
-                refresh = displayParent != null && displayParent.DateLastSaved > item.DateLastRefreshed;
+                refresh = displayParent is not null && displayParent.DateLastSaved > item.DateLastRefreshed;
             }
 
             if (refresh)
@@ -2441,7 +2443,7 @@ namespace Emby.Server.Implementations.Library
         public bool FillMissingEpisodeNumbersFromPath(Episode episode, bool forceRefresh)
         {
             var series = episode.Series;
-            bool? isAbsoluteNaming = series != null && string.Equals(series.DisplayOrder, "absolute", StringComparison.OrdinalIgnoreCase);
+            bool? isAbsoluteNaming = series is not null && string.Equals(series.DisplayOrder, "absolute", StringComparison.OrdinalIgnoreCase);
             if (!isAbsoluteNaming.Value)
             {
                 // In other words, no filter applied
@@ -2459,10 +2461,10 @@ namespace Emby.Server.Implementations.Library
                 episodeInfo = resolver.Resolve(episode.Path, isFolder, null, null, isAbsoluteNaming);
                 // Resolve from parent folder if it's not the Season folder
                 var parent = episode.GetParent();
-                if (episodeInfo == null && parent.GetType() == typeof(Folder))
+                if (episodeInfo is null && parent.GetType() == typeof(Folder))
                 {
                     episodeInfo = resolver.Resolve(parent.Path, true, null, null, isAbsoluteNaming);
-                    if (episodeInfo != null)
+                    if (episodeInfo is not null)
                     {
                         // add the container
                         episodeInfo.Container = Path.GetExtension(episode.Path)?.TrimStart('.');
@@ -2582,7 +2584,7 @@ namespace Emby.Server.Implementations.Library
             {
                 var season = episode.Season;
 
-                if (season != null)
+                if (season is not null)
                 {
                     episode.ParentIndexNumber = season.IndexNumber;
                 }
@@ -2590,9 +2592,9 @@ namespace Emby.Server.Implementations.Library
                 {
                     /*
                     Anime series don't generally have a season in their file name, however,
-                    tvdb needs a season to correctly get the metadata.
+                    TVDb needs a season to correctly get the metadata.
                     Hence, a null season needs to be filled with something. */
-                    // FIXME perhaps this would be better for tvdb parser to ask for season 1 if no season is specified
+                    // FIXME perhaps this would be better for TVDb parser to ask for season 1 if no season is specified
                     episode.ParentIndexNumber = 1;
                 }
 
@@ -2620,7 +2622,7 @@ namespace Emby.Server.Implementations.Library
         public IEnumerable<BaseItem> FindExtras(BaseItem owner, IReadOnlyList<FileSystemMetadata> fileSystemChildren, IDirectoryService directoryService)
         {
             var ownerVideoInfo = VideoResolver.Resolve(owner.Path, owner.IsFolder, _namingOptions);
-            if (ownerVideoInfo == null)
+            if (ownerVideoInfo is null)
             {
                 yield break;
             }
@@ -2640,7 +2642,7 @@ namespace Emby.Server.Implementations.Library
                         }
 
                         var extra = GetExtra(file, extraType.Value);
-                        if (extra != null)
+                        if (extra is not null)
                         {
                             yield return extra;
                         }
@@ -2649,7 +2651,7 @@ namespace Emby.Server.Implementations.Library
                 else if (!current.IsDirectory && _extraResolver.TryGetExtraTypeForOwner(current.FullName, ownerVideoInfo, out var extraType))
                 {
                     var extra = GetExtra(current, extraType.Value);
-                    if (extra != null)
+                    if (extra is not null)
                     {
                         yield return extra;
                     }
@@ -2666,7 +2668,7 @@ namespace Emby.Server.Implementations.Library
 
                 // Try to retrieve it from the db. If we don't find it, use the resolved version
                 var itemById = GetItemById(extra.Id);
-                if (itemById != null)
+                if (itemById is not null)
                 {
                     extra = itemById;
                 }
@@ -2681,10 +2683,10 @@ namespace Emby.Server.Implementations.Library
         public string GetPathAfterNetworkSubstitution(string path, BaseItem ownerItem)
         {
             string newPath;
-            if (ownerItem != null)
+            if (ownerItem is not null)
             {
                 var libraryOptions = GetLibraryOptions(ownerItem);
-                if (libraryOptions != null)
+                if (libraryOptions is not null)
                 {
                     foreach (var pathInfo in libraryOptions.PathInfos)
                     {
@@ -2753,10 +2755,8 @@ namespace Emby.Server.Implementations.Library
                     return null;
                 }
             })
-            .Where(i => i != null)
-            .Where(i => query.User == null ?
-                true :
-                i.IsVisible(query.User))
+            .Where(i => i is not null)
+            .Where(i => query.User is null || i.IsVisible(query.User))
             .ToList();
         }
 
@@ -2838,10 +2838,10 @@ namespace Emby.Server.Implementations.Library
             }
 
             var mediaPathInfos = options.PathInfos;
-            if (mediaPathInfos != null)
+            if (mediaPathInfos is not null)
             {
                 var invalidpath = mediaPathInfos.FirstOrDefault(i => !Directory.Exists(i.Path));
-                if (invalidpath != null)
+                if (invalidpath is not null)
                 {
                     throw new ArgumentException("The specified path does not exist: " + invalidpath.Path + ".");
                 }
@@ -2853,7 +2853,7 @@ namespace Emby.Server.Implementations.Library
             {
                 Directory.CreateDirectory(virtualFolderPath);
 
-                if (collectionType != null)
+                if (collectionType is not null)
                 {
                     var path = Path.Combine(virtualFolderPath, collectionType.ToString().ToLowerInvariant() + ".collection");
 
@@ -2862,7 +2862,7 @@ namespace Emby.Server.Implementations.Library
 
                 CollectionFolder.SaveLibraryOptions(virtualFolderPath, options);
 
-                if (mediaPathInfos != null)
+                if (mediaPathInfos is not null)
                 {
                     foreach (var path in mediaPathInfos)
                     {
@@ -2889,7 +2889,7 @@ namespace Emby.Server.Implementations.Library
 
         private async Task SavePeopleMetadataAsync(IEnumerable<PersonInfo> people, CancellationToken cancellationToken)
         {
-            var personsToSave = new List<BaseItem>();
+            List<BaseItem> personsToSave = null;
 
             foreach (var person in people)
             {
@@ -2931,12 +2931,12 @@ namespace Emby.Server.Implementations.Library
 
                 if (saveEntity)
                 {
-                    personsToSave.Add(personEntity);
+                    (personsToSave ??= new()).Add(personEntity);
                     await RunMetadataSavers(personEntity, itemUpdateType).ConfigureAwait(false);
                 }
             }
 
-            if (personsToSave.Count > 0)
+            if (personsToSave is not null)
             {
                 CreateItems(personsToSave, null, CancellationToken.None);
             }
@@ -3098,22 +3098,19 @@ namespace Emby.Server.Implementations.Library
                 throw new ArgumentNullException(nameof(path));
             }
 
-            var removeList = new List<NameValuePair>();
+            List<NameValuePair> removeList = null;
 
             foreach (var contentType in _configurationManager.Configuration.ContentTypes)
             {
-                if (string.IsNullOrWhiteSpace(contentType.Name))
-                {
-                    removeList.Add(contentType);
-                }
-                else if (_fileSystem.AreEqual(path, contentType.Name)
+                if (string.IsNullOrWhiteSpace(contentType.Name)
+                    || _fileSystem.AreEqual(path, contentType.Name)
                     || _fileSystem.ContainsSubPath(path, contentType.Name))
                 {
-                    removeList.Add(contentType);
+                    (removeList ??= new()).Add(contentType);
                 }
             }
 
-            if (removeList.Count > 0)
+            if (removeList is not null)
             {
                 _configurationManager.Configuration.ContentTypes = _configurationManager.Configuration.ContentTypes
                     .Except(removeList)
@@ -3125,10 +3122,7 @@ namespace Emby.Server.Implementations.Library
 
         public void RemoveMediaPath(string virtualFolderName, string mediaPath)
         {
-            if (string.IsNullOrEmpty(mediaPath))
-            {
-                throw new ArgumentNullException(nameof(mediaPath));
-            }
+            ArgumentException.ThrowIfNullOrEmpty(mediaPath);
 
             var rootFolderPath = _configurationManager.ApplicationPaths.DefaultUserViewsPath;
             var virtualFolderPath = Path.Combine(rootFolderPath, virtualFolderName);