integration/Plugins/BlueprintMCP/Source/BlueprintMCP/Private/Handlers/UMCPHandler_RemoveBlueprintComponent.h

#pragma once

#include "CoreMinimal.h"
#include "MCPHandler.h"
#include "MCPFetcher.h"
#include "MCPUtils.h"
#include "Engine/Blueprint.h"
#include "Engine/SimpleConstructionScript.h"
#include "Engine/SCS_Node.h"
#include "Kismet2/BlueprintEditorUtils.h"
#include "UMCPHandler_RemoveBlueprintComponent.generated.h"


// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------

UCLASS(meta=(Group="Unclassified"))
class UMCPHandler_RemoveBlueprintComponent : public UObject, public IMCPHandler
{
	GENERATED_BODY()

public:
	UPROPERTY(meta=(Description="Blueprint name or package path"))
	FString Blueprint;

	UPROPERTY(meta=(Description="Component to remove"))
	FString Component;

	virtual FString GetDescription() const override
	{
		return TEXT("Remove a component from a Blueprint's SimpleConstructionScript.");
	}

	virtual void Handle(const FJsonObject* Json, FStringBuilderBase& Result) override
	{
		MCPFetcher F(Result);
		UBlueprint* BP = F.Walk(Blueprint).Cast<UBlueprint>();
		if (!BP) return;

		USimpleConstructionScript* SCS = BP->SimpleConstructionScript;
		if (!SCS)
		{
			Result.Append(TEXT("ERROR: Not an Actor Blueprint (no SimpleConstructionScript).\n"));
			return;
		}

		// Find the node to remove using Identifies for consistent name matching
		USCS_Node* NodeToRemove = nullptr;
		const TArray<USCS_Node*>& AllNodes = SCS->GetAllNodes();
		for (USCS_Node* Node : AllNodes)
		{
			if (Node && Node->ComponentTemplate &&
				MCPUtils::Identifies(Component, Node->ComponentTemplate))
			{
				NodeToRemove = Node;
				break;
			}
		}

		if (!NodeToRemove)
		{
			Result.Appendf(TEXT("ERROR: Component '%s' not found.\nAvailable components:\n"),
				*Component);
			for (USCS_Node* Node : AllNodes)
			{
				if (Node && Node->ComponentTemplate)
					Result.Appendf(TEXT("  %s\n"), *MCPUtils::FormatName(Node->ComponentTemplate));
			}
			return;
		}

		// Prevent removing the root scene component if it has children
		const TArray<USCS_Node*>& RootNodes = SCS->GetRootNodes();
		if (RootNodes.Contains(NodeToRemove) && NodeToRemove->GetChildNodes().Num() > 0)
		{
			Result.Appendf(TEXT("ERROR: Cannot remove '%s' — it is a root component with %d child(ren). "
				"Remove or re-parent the children first.\n"),
				*MCPUtils::FormatName(NodeToRemove->ComponentTemplate),
				NodeToRemove->GetChildNodes().Num());
			return;
		}

		FString RemovedName = MCPUtils::FormatName(NodeToRemove->ComponentTemplate);

		// Remove the node (promotes children to parent if it has any — but we've guarded root above)
		SCS->RemoveNodeAndPromoteChildren(NodeToRemove);

		FBlueprintEditorUtils::MarkBlueprintAsStructurallyModified(BP);
		bool bSaved = MCPUtils::SaveBlueprintPackage(BP);

		Result.Appendf(TEXT("Removed component %s.%s\n"),
			*RemovedName,
			bSaved ? TEXT("") : TEXT(" WARNING: save failed."));
	}
};