Fix movie recommendations

MediaBrowser.Controller/Library/IBatchLocalSimilarItemsProvider.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Library;
+
+/// <summary>
+/// A local similar items provider that supports batch queries across multiple source items.
+/// Implementations share access filtering and entity loading across all sources for better performance.
+/// </summary>
+public interface IBatchLocalSimilarItemsProvider : ISimilarItemsProvider
+{
+    /// <summary>
+    /// Gets similar items for multiple source items in a single batch.
+    /// </summary>
+    /// <param name="sourceItems">The source items to find similar items for.</param>
+    /// <param name="query">The query options.</param>
+    /// <returns>Per-source-item results keyed by source item ID.</returns>
+    Task<Dictionary<Guid, IReadOnlyList<BaseItem>>> GetBatchSimilarItemsAsync(
+        IReadOnlyList<BaseItem> sourceItems,
+        SimilarItemsQuery query);
+}

MediaBrowser.Controller/Library/ILibraryManager.cs

@@ -597,6 +597,15 @@ namespace MediaBrowser.Controller.Library
         /// <returns>List&lt;System.String&gt;.</returns>
         IReadOnlyList<string> GetPeopleNames(InternalPeopleQuery query);
 
+        /// <summary>
+        /// Gets distinct people names for multiple items.
+        /// </summary>
+        /// <param name="itemIds">The item IDs.</param>
+        /// <param name="personTypes">The person types to include.</param>
+        /// <param name="limit">Maximum number of names.</param>
+        /// <returns>The distinct people names.</returns>
+        IReadOnlyList<string> GetPeopleNamesByItems(IReadOnlyList<Guid> itemIds, IReadOnlyList<string> personTypes, int limit);
+
         /// <summary>
         /// Queries the items.
         /// </summary>

MediaBrowser.Controller/Library/ISimilarItemsManager.cs

@@ -47,4 +47,14 @@ public interface ISimilarItemsManager
         int? limit,
         LibraryOptions? libraryOptions,
         CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Gets similar items for multiple source items in a single batch.
+    /// </summary>
+    /// <param name="sourceItems">The source items to find similar items for.</param>
+    /// <param name="query">The query options.</param>
+    /// <returns>Per-source-item results keyed by source item ID.</returns>
+    Task<Dictionary<Guid, IReadOnlyList<BaseItem>>> GetBatchSimilarItemsAsync(
+        IReadOnlyList<BaseItem> sourceItems,
+        SimilarItemsQuery query);
 }

MediaBrowser.Controller/Persistence/IPeopleRepository.cs

@@ -32,4 +32,13 @@ public interface IPeopleRepository
     /// <param name="filter">The query.</param>
     /// <returns>The list of people names matching the filter.</returns>
     IReadOnlyList<string> GetPeopleNames(InternalPeopleQuery filter);
+
+    /// <summary>
+    /// Gets distinct people names for multiple items efficiently by querying from the mapping table.
+    /// </summary>
+    /// <param name="itemIds">The item IDs to get people for.</param>
+    /// <param name="personTypes">The person types to include (e.g. "Actor", "Director").</param>
+    /// <param name="limit">Maximum number of names to return.</param>
+    /// <returns>The distinct people names.</returns>
+    IReadOnlyList<string> GetPeopleNamesByItems(IReadOnlyList<Guid> itemIds, IReadOnlyList<string> personTypes, int limit);
 }