Broad rearrangement of handlers

Plugins/BlueprintMCP/Deprecated/UMCPHandler_AddStructField.h

@@ -0,0 +1,72 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "MCPHandler.h"
+#include "MCPFetcher.h"
+#include "MCPUtils.h"
+#include "StructUtils/UserDefinedStruct.h"
+#include "UserDefinedStructure/UserDefinedStructEditorData.h"
+#include "UMCPHandler_AddStructField.generated.h"
+
+
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+
+UCLASS(meta=(Group="Unclassified"))
+class UMCPHandler_AddStructField : public UObject, public IMCPHandler
+{
+	GENERATED_BODY()
+
+public:
+	UPROPERTY(meta=(Description="Package path of the struct asset"))
+	FString Struct;
+
+	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, FStringBuilderBase& Result) override
+	{
+		// Find the struct
+		MCPFetcher F(Result);
+		UUserDefinedStruct* S = F.Walk(Struct).Cast<UUserDefinedStruct>();
+		if (!S) return;
+
+		// 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(S))
+			ExistingGuids.Add(Var.VarGuid);
+
+		if (!FStructureEditorUtils::AddVariable(S, PinType))
+		{
+			Result.Append(TEXT("ERROR: Failed to add field to struct.\n"));
+			return;
+		}
+
+		// Find the new variable by diffing GUID sets and rename it
+		for (const FStructVariableDescription& Var : FStructureEditorUtils::GetVarDesc(S))
+		{
+			if (!ExistingGuids.Contains(Var.VarGuid))
+			{
+				FStructureEditorUtils::RenameVariable(S, Var.VarGuid, Name);
+				break;
+			}
+		}
+
+		MCPUtils::SaveGenericPackage(S);
+		Result.Appendf(TEXT("Added field: %s %s\n"), *Type, *Name);
+	}
+};