fix(ui): select and examine favorite spells like retail

src/AcDream.App/Spells/MagicRuntime.cs

@@ -17,6 +17,12 @@ public sealed record SpellComponentDescriptor(
     uint Category,
     uint IconId);
 
+/// <summary>One resolved formula cell in retail's spell examination subview.</summary>
+public readonly record struct SpellExamineComponent(
+    uint SpellComponentId,
+    SpellComponentDescriptor Descriptor,
+    bool Owned);
+
 /// <summary>
 /// App-layer projection of retail's spell, component, and school-focus DAT tables.
 /// Keeping this catalog outside <c>GameWindow</c> makes the SCID/WCID boundary and
@@ -52,6 +58,20 @@ public sealed class MagicCatalog
     public CoreSpellTable SpellTable { get; }
     public IReadOnlyDictionary<uint, SpellComponentDescriptor> Components { get; }
 
+    public bool TryGetComponentBySpellComponentId(
+        uint spellComponentId,
+        out SpellComponentDescriptor descriptor)
+    {
+        if (_wcidByScid.TryGetValue(spellComponentId, out uint weenieClassId)
+            && Components.TryGetValue(weenieClassId, out SpellComponentDescriptor? found))
+        {
+            descriptor = found;
+            return true;
+        }
+        descriptor = null!;
+        return false;
+    }
+
     public bool IsComponentPack(uint weenieClassId)
         => Components.ContainsKey(weenieClassId);
 
@@ -143,15 +163,43 @@ public sealed class MagicCatalog
 /// </summary>
 public sealed class MagicRuntime
 {
-    private MagicRuntime(MagicCatalog catalog, SpellCastingController casting)
+    private readonly SpellComponentRequirementService _requirements;
+
+    private MagicRuntime(
+        MagicCatalog catalog,
+        SpellCastingController casting,
+        SpellComponentRequirementService requirements)
     {
         Catalog = catalog;
         Casting = casting;
+        _requirements = requirements;
     }
 
     public MagicCatalog Catalog { get; }
     public SpellCastingController Casting { get; }
 
+    public IReadOnlyList<SpellExamineComponent> GetExamineComponents(uint spellId)
+    {
+        IReadOnlyList<uint> formula = _requirements.GetAppropriateFormula(spellId);
+        if (formula.Count == 0)
+            return [];
+
+        var result = new List<SpellExamineComponent>(formula.Count);
+        foreach (uint spellComponentId in formula)
+        {
+            if (spellComponentId == 0u
+                || !Catalog.TryGetComponentBySpellComponentId(
+                    spellComponentId,
+                    out SpellComponentDescriptor descriptor))
+                continue;
+            result.Add(new SpellExamineComponent(
+                spellComponentId,
+                descriptor,
+                _requirements.IsComponentOwned(spellComponentId)));
+        }
+        return result;
+    }
+
     public static MagicRuntime Create(
         MagicCatalog catalog,
         Spellbook spellbook,
@@ -198,7 +246,7 @@ public sealed class MagicRuntime
             incrementBusy: incrementBusy,
             canSend: canSend,
             targetCompatibleSilent: (target, spell) => TargetCompatible(target, spell, false));
-        return new MagicRuntime(catalog, casting);
+        return new MagicRuntime(catalog, casting, requirements);
     }
 
     public void Reset() => Casting.Reset();

src/AcDream.App/Spells/SpellComponentRequirementService.cs

@@ -75,6 +75,31 @@ public sealed class SpellComponentRequirementService
     /// (0x00567D50): an infused school or a directly carried school focus uses
     /// the scarab-only formula; otherwise the account-customized formula wins.
     /// </summary>
+    public IReadOnlyList<uint> GetAppropriateFormula(uint spellId)
+    {
+        if (!_formulas.TryGetValue(spellId, out SpellFormulaDefinition? formula))
+            return [];
+        uint playerGuid = _playerGuid();
+        return GetAppropriateFormula(
+            formula,
+            _objects.Get(playerGuid),
+            playerGuid);
+    }
+
+    /// <summary>
+    /// Whether the component tracker would leave a formula icon unghosted.
+    /// The input is a retail spell-component id (SCID), not a weenie class id.
+    /// </summary>
+    public bool IsComponentOwned(uint spellComponentId)
+    {
+        if (!_wcidByScid.TryGetValue(spellComponentId, out uint weenieClassId))
+            return false;
+        uint playerGuid = _playerGuid();
+        return _objects.Objects.Any(item =>
+            item.WeenieClassId == weenieClassId
+            && IsOwnedByPlayer(item, playerGuid));
+    }
+
     private IReadOnlyList<uint> GetAppropriateFormula(
         SpellFormulaDefinition formula,
         ClientObject? player,