From 5e840c1db62d2ec86b2fdaee02d6b0521368bbfc Mon Sep 17 00:00:00 2001
From: ItsAllAboutTheCode <52703+ItsAllAboutTheCode@users.noreply.github.com>
Date: Mon, 15 Jul 2024 07:44:06 -0500
Subject: [PATCH] Improve LibraryManager.Sort when using "Random" order
 (#12165)

Co-authored-by: Cody Robibero <cody@robibe.ro>
---
 CONTRIBUTORS.md                               |  1 +
 .../Library/LibraryManager.cs                 | 30 ++++++++++++-------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index 8f63bd6b4..edbc846d6 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -185,6 +185,7 @@
  - [Vedant](https://github.com/viktory36/)
  - [NotSaifA](https://github.com/NotSaifA)
  - [HonestlyWhoKnows](https://github.com/honestlywhoknows)
+ - [ItsAllAboutTheCode](https://github.com/ItsAllAboutTheCode)
 
 # Emby Contributors
 
diff --git a/Emby.Server.Implementations/Library/LibraryManager.cs b/Emby.Server.Implementations/Library/LibraryManager.cs
index ac2248264..cbded1ec6 100644
--- a/Emby.Server.Implementations/Library/LibraryManager.cs
+++ b/Emby.Server.Implementations/Library/LibraryManager.cs
@@ -1,4 +1,5 @@
 #pragma warning disable CS1591
+#pragma warning disable CA5394
 
 using System;
 using System.Collections.Concurrent;
@@ -16,6 +17,7 @@ using Emby.Server.Implementations.Library.Resolvers;
 using Emby.Server.Implementations.Library.Validators;
 using Emby.Server.Implementations.Playlists;
 using Emby.Server.Implementations.ScheduledTasks.Tasks;
+using Emby.Server.Implementations.Sorting;
 using Jellyfin.Data.Entities;
 using Jellyfin.Data.Enums;
 using Jellyfin.Extensions;
@@ -1710,13 +1712,19 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public IEnumerable<BaseItem> Sort(IEnumerable<BaseItem> items, User? user, IEnumerable<ItemSortBy> sortBy, SortOrder sortOrder)
         {
-            var isFirst = true;
-
             IOrderedEnumerable<BaseItem>? orderedItems = null;
 
             foreach (var orderBy in sortBy.Select(o => GetComparer(o, user)).Where(c => c is not null))
             {
-                if (isFirst)
+                if (orderBy is RandomComparer)
+                {
+                    var randomItems = items.ToArray();
+                    Random.Shared.Shuffle(randomItems);
+                    items = randomItems;
+                    // Items are no longer ordered at this point, so set orderedItems back to null
+                    orderedItems = null;
+                }
+                else if (orderedItems is null)
                 {
                     orderedItems = sortOrder == SortOrder.Descending
                         ? items.OrderByDescending(i => i, orderBy)
@@ -1728,8 +1736,6 @@ namespace Emby.Server.Implementations.Library
                         ? orderedItems!.ThenByDescending(i => i, orderBy)
                         : orderedItems!.ThenBy(i => i, orderBy); // orderedItems is set during the first iteration
                 }
-
-                isFirst = false;
             }
 
             return orderedItems ?? items;
@@ -1738,8 +1744,6 @@ namespace Emby.Server.Implementations.Library
         /// <inheritdoc />
         public IEnumerable<BaseItem> Sort(IEnumerable<BaseItem> items, User? user, IEnumerable<(ItemSortBy OrderBy, SortOrder SortOrder)> orderBy)
         {
-            var isFirst = true;
-
             IOrderedEnumerable<BaseItem>? orderedItems = null;
 
             foreach (var (name, sortOrder) in orderBy)
@@ -1750,7 +1754,15 @@ namespace Emby.Server.Implementations.Library
                     continue;
                 }
 
-                if (isFirst)
+                if (comparer is RandomComparer)
+                {
+                    var randomItems = items.ToArray();
+                    Random.Shared.Shuffle(randomItems);
+                    items = randomItems;
+                    // Items are no longer ordered at this point, so set orderedItems back to null
+                    orderedItems = null;
+                }
+                else if (orderedItems is null)
                 {
                     orderedItems = sortOrder == SortOrder.Descending
                         ? items.OrderByDescending(i => i, comparer)
@@ -1762,8 +1774,6 @@ namespace Emby.Server.Implementations.Library
                         ? orderedItems!.ThenByDescending(i => i, comparer)
                         : orderedItems!.ThenBy(i => i, comparer); // orderedItems is set during the first iteration
                 }
-
-                isFirst = false;
             }
 
             return orderedItems ?? items;