From 309c8522227d63d647847ad0cf90ccf1f5ffd6eb Mon Sep 17 00:00:00 2001
From: Aki <75532970+AkiSakurai@users.noreply.github.com>
Date: Sat, 15 Jul 2023 22:12:48 +0800
Subject: [PATCH] Compute the top local rank directly without an expensive
 detach call

---
 osu.Game/Scoring/ScoreInfoExtensions.cs          | 8 ++++++++
 osu.Game/Screens/Select/Carousel/TopLocalRank.cs | 3 +--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Scoring/ScoreInfoExtensions.cs b/osu.Game/Scoring/ScoreInfoExtensions.cs
index 6e57a9fd0b..63cc077cde 100644
--- a/osu.Game/Scoring/ScoreInfoExtensions.cs
+++ b/osu.Game/Scoring/ScoreInfoExtensions.cs
@@ -32,5 +32,13 @@ namespace osu.Game.Scoring
         /// <param name="score">The <see cref="ScoreInfo"/> to compute the maximum achievable combo for.</param>
         /// <returns>The maximum achievable combo.</returns>
         public static int GetMaximumAchievableCombo(this ScoreInfo score) => score.MaximumStatistics.Where(kvp => kvp.Key.AffectsCombo()).Sum(kvp => kvp.Value);
+
+        /// <summary>
+        /// Retrieves the <see cref="ScoreInfo"/> with the maximum total score.
+        /// </summary>
+        /// <param name="scores">An array of <see cref="ScoreInfo"/>s to retrieve the scoreInfo with maximum total score.</param>
+        /// <returns>The <see cref="ScoreInfo"/> instance with the maximum total score.</returns>
+        public static ScoreInfo? MaxByTopScore(this IEnumerable<ScoreInfo> scores)
+            => scores.MaxBy(info => (info.TotalScore, -info.OnlineID, -info.Date.UtcDateTime.Ticks));
     }
 }
diff --git a/osu.Game/Screens/Select/Carousel/TopLocalRank.cs b/osu.Game/Screens/Select/Carousel/TopLocalRank.cs
index c17de77619..fe2d79b080 100644
--- a/osu.Game/Screens/Select/Carousel/TopLocalRank.cs
+++ b/osu.Game/Screens/Select/Carousel/TopLocalRank.cs
@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -75,7 +74,7 @@ namespace osu.Game.Screens.Select.Carousel
                 if (changes?.HasCollectionChanges() == false)
                     return;
 
-                ScoreInfo? topScore = sender.Detach().OrderByTotalScore().FirstOrDefault();
+                ScoreInfo? topScore = sender.MaxByTopScore();
 
                 updateable.Rank = topScore?.Rank;
                 updateable.Alpha = topScore != null ? 1 : 0;