Split MCP handlers

Plugins/BlueprintMCP/Source/BlueprintMCP/Private/Handlers/UMCPHandler_AddStructField.h

@@ -0,0 +1,85 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "MCPHandler.h"
+#include "MCPAssetFinder.h"
+#include "MCPUtils.h"
+#include "StructUtils/UserDefinedStruct.h"
+#include "Engine/UserDefinedEnum.h"
+#include "Kismet2/BlueprintEditorUtils.h"
+#include "UserDefinedStructure/UserDefinedStructEditorData.h"
+#include "Kismet2/EnumEditorUtils.h"
+#include "AssetRegistry/AssetRegistryModule.h"
+#include "AssetRegistry/IAssetRegistry.h"
+#include "AssetToolsModule.h"
+#include "IAssetTools.h"
+#include "Factories/StructureFactory.h"
+#include "Factories/EnumFactory.h"
+#include "UMCPHandler_AddStructField.generated.h"
+
+
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+
+UCLASS()
+class UMCPHandler_AddStructField : public UObject, public IMCPHandler
+{
+	GENERATED_BODY()
+
+public:
+	UPROPERTY(meta=(Description="Name or package path of the struct asset"))
+	FString AssetPath;
+
+	UPROPERTY(meta=(Description="Name for the new field"))
+	FString Name;
+
+	UPROPERTY(meta=(Description="Type for the new field (e.g. 'int32', 'FString', 'FVector')"))
+	FString Type;
+
+	virtual FString GetDescription() const override
+	{
+		return TEXT("Add a new field to a UserDefinedStruct asset.");
+	}
+
+	virtual void Handle(const FJsonObject* Json, FJsonObject* Result) override
+	{
+    	// Find the struct
+    	MCPAssets<UUserDefinedStruct> Assets;
+    	if (!Assets.Exact(AssetPath).Errors(Result).ENone().ETwo().Load()) return;
+    	UUserDefinedStruct* Struct = Assets.Object();
+
+    	// Resolve type
+    	FEdGraphPinType PinType;
+    	if (!MCPUtils::ResolveTypeFromString(Type, PinType, Result))
+    		return;
+
+    	// Snapshot existing GUIDs so we can find the newly added one
+    	TSet<FGuid> ExistingGuids;
+    	for (const FStructVariableDescription& Var : FStructureEditorUtils::GetVarDesc(Struct))
+    	{
+    		ExistingGuids.Add(Var.VarGuid);
+    	}
+
+    	bool bAdded = FStructureEditorUtils::AddVariable(Struct, PinType);
+    	if (!bAdded)
+    	{
+    		return MCPUtils::MakeErrorJson(Result, TEXT("Failed to add property to struct"));
+    	}
+
+    	// Find the new variable by diffing GUID sets and rename it
+    	for (const FStructVariableDescription& Var : FStructureEditorUtils::GetVarDesc(Struct))
+    	{
+    		if (!ExistingGuids.Contains(Var.VarGuid))
+    		{
+    			FStructureEditorUtils::RenameVariable(Struct, Var.VarGuid, Name);
+    			break;
+    		}
+    	}
+
+    	// Save
+    	bool bSaved = MCPUtils::SaveGenericPackage(Struct);
+
+    	Result->SetBoolField(TEXT("saved"), bSaved);
+	}
+};