feat: variadic register/unregister with shared rebuild helpers

CommandHook/CommandHookModSystem.cs

@@ -31,29 +31,44 @@ public class CommandHookModSystem : ModSystem
         Instance = null;
     }
 
-    public void Register(string modId, string commandName, CommandRegistration registration)
+    public void Register(
+        string modId,
+        CommandRegistration registration,
+        params string[] commandNames
+    )
     {
-        var builder = new Dictionary<string, Dictionary<string, CommandRegistration>>();
+        var builder = Thaw();
 
-        foreach (var (cmd, mods) in registrations)
+        foreach (var commandName in commandNames)
         {
-            var inner = new Dictionary<string, CommandRegistration>();
-            foreach (var (id, reg) in mods)
-                inner[id] = reg;
-            builder[cmd] = inner;
+            if (!builder.TryGetValue(commandName, out var target))
+            {
+                target = new Dictionary<string, CommandRegistration>();
+                builder[commandName] = target;
+            }
+            target[modId] = registration;
         }
 
-        if (!builder.TryGetValue(commandName, out var target))
-        {
-            target = new Dictionary<string, CommandRegistration>();
-            builder[commandName] = target;
-        }
-        target[modId] = registration;
+        registrations = Freeze(builder);
+    }
 
-        registrations = builder.ToFrozenDictionary(
-            pair => pair.Key,
-            pair => pair.Value.ToFrozenDictionary()
-        );
+    public void Unregister(string modId, params string[] commandNames)
+    {
+        var builder = Thaw();
+
+        if (commandNames.Length == 0)
+        {
+            foreach (var (_, mods) in builder)
+                mods.Remove(modId);
+        }
+        else
+        {
+            foreach (var commandName in commandNames)
+                if (builder.TryGetValue(commandName, out var mods))
+                    mods.Remove(modId);
+        }
+
+        registrations = Freeze(builder);
     }
 
     public bool FireBefore(string commandName, ref CommandData data)
@@ -71,4 +86,32 @@ public class CommandHookModSystem : ModSystem
             foreach (var (_, reg) in mods)
                 reg.After?.Invoke(ref data, result);
     }
+
+    private Dictionary<string, Dictionary<string, CommandRegistration>> Thaw()
+    {
+        var builder = new Dictionary<string, Dictionary<string, CommandRegistration>>();
+
+        foreach (var (cmd, mods) in registrations)
+        {
+            var inner = new Dictionary<string, CommandRegistration>();
+            foreach (var (id, reg) in mods)
+                inner[id] = reg;
+            builder[cmd] = inner;
+        }
+
+        return builder;
+    }
+
+    private static FrozenDictionary<string, FrozenDictionary<string, CommandRegistration>> Freeze(
+        Dictionary<string, Dictionary<string, CommandRegistration>> builder
+    )
+    {
+        var pruned = new Dictionary<string, FrozenDictionary<string, CommandRegistration>>();
+
+        foreach (var (cmd, mods) in builder)
+            if (mods.Count > 0)
+                pruned[cmd] = mods.ToFrozenDictionary();
+
+        return pruned.ToFrozenDictionary();
+    }
 }