#pragma once

#include "CoreMinimal.h"
#include "MCPHandler.h"
#include "MCPAssets.h"
#include "MCPFetcher.h"
#include "MCPUtils.h"
#include "Materials/Material.h"
#include "Materials/MaterialExpression.h"
#include "Materials/MaterialFunction.h"
#include "MaterialGraph/MaterialGraph.h"
#include "EdGraph/EdGraph.h"
#include "EdGraph/EdGraphNode.h"
#include "EdGraph/EdGraphPin.h"
#include "UMCPHandler_DisconnectMaterialExpressionPin.generated.h"


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

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

public:
	UPROPERTY(meta=(Optional, Description="Material name or package path (specify this or materialFunction)"))
	FString Material;

	UPROPERTY(meta=(Optional, Description="Material function name or package path (specify this or material)"))
	FString MaterialFunction;

	UPROPERTY(meta=(Description="Node name (use FormatName-style identifier)"))
	FString Node;

	UPROPERTY(meta=(Description="Pin name to disconnect"))
	FString PinName;

	virtual FString GetDescription() const override
	{
		return TEXT("Break all connections on a specific pin in a material or material function graph.");
	}

	virtual void Handle(const FJsonObject* Json, FStringBuilderBase& Result) override
	{
		if (Material.IsEmpty() && MaterialFunction.IsEmpty())
		{
			Result.Append(TEXT("ERROR: Specify 'material' or 'materialFunction'.\n"));
			return;
		}

		// Load material or material function
		UMaterial* MaterialObj = nullptr;
		UMaterialFunction* MatFunc = nullptr;

		if (!MaterialFunction.IsEmpty())
		{
			MCPAssets<UMaterialFunction> Assets;
			if (!Assets.Exact(MaterialFunction).Errors(Result).ENone().ETwo().Load()) return;
			MatFunc = Assets.Object();
		}
		else
		{
			MCPAssets<UMaterial> Assets;
			if (!Assets.Exact(Material).Errors(Result).ENone().ETwo().Load()) return;
			MaterialObj = Assets.Object();
		}

		if (MaterialObj) MCPUtils::EnsureMaterialGraph(MaterialObj);
		UEdGraph* Graph = MaterialObj ? (UEdGraph*)MaterialObj->MaterialGraph : (MatFunc ? MatFunc->MaterialGraph : nullptr);
		if (!Graph)
		{
			Result.Appendf(TEXT("ERROR: %s has no material graph.\n"),
				MaterialObj ? *MCPUtils::FormatName(MaterialObj) : *MCPUtils::FormatName(MatFunc));
			return;
		}

		// Find node and pin via MCPFetcher
		MCPFetcher F(Result, Graph);
		UEdGraphPin* Pin = F.Node(Node).Pin(PinName).Cast<UEdGraphPin>();
		if (!Pin) return;

		int32 BrokenCount = Pin->LinkedTo.Num();
		Pin->BreakAllPinLinks();

		UObject* Asset = MaterialObj ? (UObject*)MaterialObj : (UObject*)MatFunc;
		Asset->PreEditChange(nullptr);
		Asset->PostEditChange();

		bool bSaved = MaterialObj ? MCPUtils::SaveMaterialPackage(MaterialObj) : MCPUtils::SaveGenericPackage(MatFunc);

		Result.Appendf(TEXT("Disconnected %d link(s) from %s on %s.\n"),
			BrokenCount, *MCPUtils::FormatName(Pin), *MCPUtils::FormatName(Pin->GetOwningNode()));
		if (!bSaved)
			Result.Append(TEXT("WARNING: Failed to save package.\n"));
	}
};