Decouple AdvancedStats from global mods

Closes https://github.com/ppy/osu/issues/30163.

If I'm to be blunt, the decoupled stuff in song select makes my head
spin. I spent a solid 20 minutes thinking how I was going to fix this
one but then finally realised that generally most of the cause there
was the fact that `AdvancedStats` was seeing the new rulesets *before*
the "ensure global selected mods are valid for current ruleset" logic,
and so decided to just _delay_ that until the decoupled transfer
thingamajig happens.

I was honestly considering combining `BeatmapInfo`, `Ruleset`, and
`Mods` into one property on `AdvancedStats`. I figured I'd rather not
push my luck and try the baseline version first, but I honestly think
that direction is going to be required at some point to properly corral
all of the decoupled madness taking place in song select.

osu.Game.Tests/Visual/SongSelect/TestSceneAdvancedStats.cs

@@ -84,7 +84,7 @@ namespace osu.Game.Tests.Visual.SongSelect
             AddStep("select EZ mod", () =>
             {
                 var ruleset = advancedStats.BeatmapInfo.Ruleset.CreateInstance().AsNonNull();
-                SelectedMods.Value = new[] { ruleset.CreateMod<ModEasy>() };
+                advancedStats.Mods.Value = new[] { ruleset.CreateMod<ModEasy>() };
             });
 
             AddAssert("circle size bar is blue", () => barIsBlue(advancedStats.FirstValue));
@@ -101,7 +101,7 @@ namespace osu.Game.Tests.Visual.SongSelect
             AddStep("select HR mod", () =>
             {
                 var ruleset = advancedStats.BeatmapInfo.Ruleset.CreateInstance().AsNonNull();
-                SelectedMods.Value = new[] { ruleset.CreateMod<ModHardRock>() };
+                advancedStats.Mods.Value = new[] { ruleset.CreateMod<ModHardRock>() };
             });
 
             AddAssert("circle size bar is red", () => barIsRed(advancedStats.FirstValue));
@@ -120,7 +120,7 @@ namespace osu.Game.Tests.Visual.SongSelect
                 var ruleset = advancedStats.BeatmapInfo.Ruleset.CreateInstance().AsNonNull();
                 var difficultyAdjustMod = ruleset.CreateMod<ModDifficultyAdjust>().AsNonNull();
                 difficultyAdjustMod.ReadFromDifficulty(advancedStats.BeatmapInfo.Difficulty);
-                SelectedMods.Value = new[] { difficultyAdjustMod };
+                advancedStats.Mods.Value = new[] { difficultyAdjustMod };
             });
 
             AddAssert("circle size bar is white", () => barIsWhite(advancedStats.FirstValue));
@@ -143,7 +143,7 @@ namespace osu.Game.Tests.Visual.SongSelect
                 difficultyAdjustMod.ReadFromDifficulty(originalDifficulty);
                 difficultyAdjustMod.DrainRate.Value = originalDifficulty.DrainRate - 0.5f;
                 difficultyAdjustMod.ApproachRate.Value = originalDifficulty.ApproachRate + 2.2f;
-                SelectedMods.Value = new[] { difficultyAdjustMod };
+                advancedStats.Mods.Value = new[] { difficultyAdjustMod };
             });
 
             AddAssert("circle size bar is white", () => barIsWhite(advancedStats.FirstValue));

osu.Game/Screens/Select/Details/AdvancedStats.cs

@@ -3,6 +3,7 @@
 
 #nullable disable
 
+using System;
 using osuTK.Graphics;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.Color4Extensions;
@@ -36,9 +37,6 @@ namespace osu.Game.Screens.Select.Details
         [Resolved]
         private BeatmapDifficultyCache difficultyCache { get; set; }
 
-        [Resolved]
-        private IBindable<IReadOnlyList<Mod>> mods { get; set; }
-
         protected readonly StatisticRow FirstValue, HpDrain, Accuracy, ApproachRate;
         private readonly StatisticRow starDifficulty;
 
@@ -69,6 +67,14 @@ namespace osu.Game.Screens.Select.Details
         /// </remarks>
         public Bindable<RulesetInfo> Ruleset { get; } = new Bindable<RulesetInfo>();
 
+        /// <summary>
+        /// Mods to be used for certain elements of display.
+        /// </summary>
+        /// <remarks>
+        /// No checks are done as to whether the mods specified are valid for the current <see cref="Ruleset"/>.
+        /// </remarks>
+        public Bindable<IReadOnlyList<Mod>> Mods { get; } = new Bindable<IReadOnlyList<Mod>>(Array.Empty<Mod>());
+
         public AdvancedStats(int columns = 1)
         {
             switch (columns)
@@ -143,8 +149,7 @@ namespace osu.Game.Screens.Select.Details
             base.LoadComplete();
 
             Ruleset.BindValueChanged(_ => updateStatistics());
-
+            Mods.BindValueChanged(modsChanged, true);
-            mods.BindValueChanged(modsChanged, true);
         }
 
         private ModSettingChangeTracker modSettingChangeTracker;
@@ -173,14 +178,14 @@ namespace osu.Game.Screens.Select.Details
             {
                 BeatmapDifficulty originalDifficulty = new BeatmapDifficulty(baseDifficulty);
 
-                foreach (var mod in mods.Value.OfType<IApplicableToDifficulty>())
+                foreach (var mod in Mods.Value.OfType<IApplicableToDifficulty>())
                     mod.ApplyToDifficulty(originalDifficulty);
 
                 adjustedDifficulty = originalDifficulty;
 
                 if (Ruleset.Value != null)
                 {
-                    double rate = ModUtils.CalculateRateWithMods(mods.Value);
+                    double rate = ModUtils.CalculateRateWithMods(Mods.Value);
 
                     adjustedDifficulty = Ruleset.Value.CreateInstance().GetRateAdjustedDisplayDifficulty(originalDifficulty, rate);
 
@@ -198,7 +203,7 @@ namespace osu.Game.Screens.Select.Details
                     // For the time being, the key count is static no matter what, because:
                     // a) The method doesn't have knowledge of the active keymods. Doing so may require considerations for filtering.
                     // b) Using the difficulty adjustment mod to adjust OD doesn't have an effect on conversion.
-                    int keyCount = baseDifficulty == null ? 0 : legacyRuleset.GetKeyCount(BeatmapInfo, mods.Value);
+                    int keyCount = baseDifficulty == null ? 0 : legacyRuleset.GetKeyCount(BeatmapInfo, Mods.Value);
 
                     FirstValue.Title = BeatmapsetsStrings.ShowStatsCsMania;
                     FirstValue.Value = (keyCount, keyCount);
@@ -236,7 +241,7 @@ namespace osu.Game.Screens.Select.Details
             starDifficultyCancellationSource = new CancellationTokenSource();
 
             var normalStarDifficultyTask = difficultyCache.GetDifficultyAsync(BeatmapInfo, Ruleset.Value, null, starDifficultyCancellationSource.Token);
-            var moddedStarDifficultyTask = difficultyCache.GetDifficultyAsync(BeatmapInfo, Ruleset.Value, mods.Value, starDifficultyCancellationSource.Token);
+            var moddedStarDifficultyTask = difficultyCache.GetDifficultyAsync(BeatmapInfo, Ruleset.Value, Mods.Value, starDifficultyCancellationSource.Token);
 
             Task.WhenAll(normalStarDifficultyTask, moddedStarDifficultyTask).ContinueWith(_ => Schedule(() =>
             {

osu.Game/Screens/Select/SongSelect.cs

@@ -610,11 +610,6 @@ namespace osu.Game.Screens.Select
                 beatmapInfoPrevious = beatmap;
             }
 
-            // we can't run this in the debounced run due to the selected mods bindable not being debounced,
-            // since mods could be updated to the new ruleset instances while the decoupled bindable is held behind,
-            // therefore resulting in performing difficulty calculation with invalid states.
-            advancedStats.Ruleset.Value = ruleset;
-
             void run()
             {
                 // clear pending task immediately to track any potential nested debounce operation.
@@ -878,6 +873,8 @@ namespace osu.Game.Screens.Select
             ModSelect.Beatmap.Value = beatmap;
 
             advancedStats.BeatmapInfo = beatmap.BeatmapInfo;
+            advancedStats.Mods.Value = selectedMods.Value;
+            advancedStats.Ruleset.Value = Ruleset.Value;
 
             bool beatmapSelected = beatmap is not DummyWorkingBeatmap;
 
@@ -990,6 +987,12 @@ namespace osu.Game.Screens.Select
 
             Beatmap.BindValueChanged(updateCarouselSelection);
 
+            selectedMods.BindValueChanged(_ =>
+            {
+                if (decoupledRuleset.Value.Equals(rulesetNoDebounce))
+                    advancedStats.Mods.Value = selectedMods.Value;
+            }, true);
+
             boundLocalBindables = true;
         }