From 92e22c57a77a2860e2ddc78ee85da46f2e5f43d4 Mon Sep 17 00:00:00 2001
From: Salman Ahmed <frenzibyte@gmail.com>
Date: Fri, 11 Feb 2022 08:02:51 +0300
Subject: [PATCH] Introduce private `APIRuleset` for online ID equality
 comparison

---
 .../API/Requests/Responses/APIBeatmap.cs      | 26 ++++++++++++++++++-
 osu.Game/Rulesets/RulesetInfo.cs              |  3 ---
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/osu.Game/Online/API/Requests/Responses/APIBeatmap.cs b/osu.Game/Online/API/Requests/Responses/APIBeatmap.cs
index ebbac0dcabf3..dca60e54cbe9 100644
--- a/osu.Game/Online/API/Requests/Responses/APIBeatmap.cs
+++ b/osu.Game/Online/API/Requests/Responses/APIBeatmap.cs
@@ -98,7 +98,7 @@ private double lengthInSeconds
 
         public string MD5Hash => Checksum;
 
-        public IRulesetInfo Ruleset => new RulesetInfo { OnlineID = RulesetID };
+        public IRulesetInfo Ruleset => new APIRuleset { OnlineID = RulesetID };
 
         [JsonIgnore]
         public string Hash => throw new NotImplementedException();
@@ -106,5 +106,29 @@ private double lengthInSeconds
         #endregion
 
         public bool Equals(IBeatmapInfo? other) => other is APIBeatmap b && this.MatchesOnlineID(b);
+
+        private class APIRuleset : IRulesetInfo
+        {
+            public int OnlineID { get; set; } = -1;
+
+            public string Name => $@"{nameof(APIRuleset)} (ID: {OnlineID})";
+            public string ShortName => nameof(APIRuleset);
+            public string InstantiationInfo => string.Empty;
+
+            public Ruleset CreateInstance() => throw new NotImplementedException();
+
+            public bool Equals(IRulesetInfo? other) => other is APIRuleset r && this.MatchesOnlineID(r);
+
+            public int CompareTo(IRulesetInfo other)
+            {
+                if (!(other is APIRuleset ruleset))
+                    throw new ArgumentException($@"Object is not of type {nameof(APIRuleset)}.", nameof(other));
+
+                return OnlineID.CompareTo(ruleset.OnlineID);
+            }
+
+            // ReSharper disable once NonReadonlyMemberInGetHashCode
+            public override int GetHashCode() => OnlineID;
+        }
     }
 }
diff --git a/osu.Game/Rulesets/RulesetInfo.cs b/osu.Game/Rulesets/RulesetInfo.cs
index ba7c8d191d67..88e398843178 100644
--- a/osu.Game/Rulesets/RulesetInfo.cs
+++ b/osu.Game/Rulesets/RulesetInfo.cs
@@ -44,9 +44,6 @@ public bool Equals(RulesetInfo? other)
             if (ReferenceEquals(this, other)) return true;
             if (other == null) return false;
 
-            if (OnlineID >= 0 && other.OnlineID >= 0)
-                return OnlineID == other.OnlineID;
-
             return ShortName == other.ShortName;
         }