integration/Plugins/BlueprintMCP/Source/BlueprintMCP/Public/MCPUtils.h

#pragma once

#include "CoreMinimal.h"
#include "Dom/JsonObject.h"
#include "EdGraph/EdGraphPin.h"

class UBlueprint;
class UEdGraph;
class UEdGraphNode;
class UEdGraphPin;
class UMaterial;
class UMaterialExpression;
class UBlueprintNodeSpawner;
class UAnimationStateMachineGraph;
class UAnimStateNode;
class UAnimStateTransitionNode;

// ----- Log capture -----

class FLogCaptureOutputDevice : public FOutputDevice
{
public:
	TArray<FString> CapturedErrors;
	TArray<FString> CapturedWarnings;

	virtual void Serialize(const TCHAR* V, ELogVerbosity::Type Verbosity, const FName& Category) override
	{
		FString Msg(V);

		if (Verbosity == ELogVerbosity::Error || Verbosity == ELogVerbosity::Fatal)
		{
			CapturedErrors.Add(Msg);
			return;
		}

		if (Verbosity == ELogVerbosity::Warning)
		{
			if (!Msg.Contains(TEXT("BlueprintMCP:")))
			{
				CapturedWarnings.Add(Msg);
			}
			return;
		}

		static const TCHAR* ErrorPatterns[] = {
			TEXT("Can't connect pins"),
			TEXT("Fixed up function"),
			TEXT("is not compatible with"),
			TEXT("could not find a pin"),
			TEXT("has an invalid"),
			TEXT("orphaned pin"),
			TEXT("is deprecated"),
			TEXT("does not implement"),
			TEXT("Missing function"),
			TEXT("Unable to find"),
			TEXT("Failed to resolve"),
		};

		for (const TCHAR* Pattern : ErrorPatterns)
		{
			if (Msg.Contains(Pattern))
			{
				CapturedWarnings.Add(Msg);
				return;
			}
		}
	}
};

// ----- Error callback -----

struct MCPErrorCallback
{
	TFunction<void(const FString&)> Func;


	MCPErrorCallback(std::nullptr_t);
	MCPErrorCallback(FString& OutError);
	MCPErrorCallback(FJsonObject* Result);

	void SetError(const FString& Msg) const { Func(Msg); }
};

// Stateless utility functions used by MCP handlers and the MCP server.
// This is effectively a namespace — all methods are static.
class MCPUtils
{
public:
	// ----- Asset path helpers -----
	// Splits "/Game/Foo/Bar" into PackagePath="/Game/Foo" and AssetName="Bar".
	// Returns false if the path has no slash or the asset name is empty.
	static bool SplitAssetPath(const FString& AssetPath, FString& OutPackagePath, FString& OutAssetName)
	{
		int32 LastSlash;
		if (!AssetPath.FindLastChar('/', LastSlash))
		{
			return false;
		}
		OutPackagePath = AssetPath.Left(LastSlash);
		OutAssetName = AssetPath.Mid(LastSlash + 1);
		return !OutAssetName.IsEmpty();
	}

	// ----- JSON helpers -----
	static FString JsonToString(TSharedRef<FJsonObject> JsonObj);
	static TSharedPtr<FJsonObject> ParseBodyJson(const FString& Body);
	static FString MakeErrorJson(const FString& Message);
	static void MakeErrorJson(FJsonObject* Result, const FString& Message);
	static void CopyJsonFields(const FJsonObject* Source, FJsonObject* Dest);
	static FString UrlDecode(const FString& EncodedString);

	// ----- Enum helpers -----
	// Convert enum value to string. If Prefix is specified, strip "Prefix_" from the front.
	template<typename T>
	static FString EnumToString(T Value, const FString& Prefix = FString())
	{
		UEnum* Enum = StaticEnum<T>();
		FString Full = Enum->GetNameStringByValue((int64)Value);
		if (!Prefix.IsEmpty() && Full.StartsWith(Prefix))
			return Full.Mid(Prefix.Len());
		return Full;
	}

	// Convert string to enum value. If Prefix is specified, prepend it before lookup.
	// Returns false and sets error if the string doesn't match any value.
	template<typename T>
	static bool StringToEnum(const FString& Str, T& OutValue, MCPErrorCallback Error, const FString& Prefix = FString())
	{
		UEnum* Enum = StaticEnum<T>();
		int64 Value = Enum->GetValueByNameString(Prefix + Str);
		if (Value == INDEX_NONE)
		{
			Error.SetError(FString::Printf(TEXT("Invalid value '%s' for %s"), *Str, *Enum->GetName()));
			return false;
		}
		OutValue = (T)Value;
		return true;
	}

	// ----- Blueprint helpers -----
	static TArray<UEdGraph*> AllGraphs(UBlueprint* BP);
	static TArray<UEdGraph*> AllGraphsNamed(UBlueprint* BP, const FString& Name);
	static TArray<UEdGraphNode*> AllNodes(UBlueprint* BP);
	template<class T> static TArray<T*> AllNodes(UBlueprint* BP)
	{
		TArray<T*> Result;
		for (UEdGraph* Graph : AllGraphs(BP))
			for (UEdGraphNode* Node : Graph->Nodes)
				if (T* Typed = Cast<T>(Node))
					Result.Add(Typed);
		return Result;
	}
	template<class T> static TArray<T*> AllNodes(UEdGraph* Graph)
	{
		TArray<T*> Result;
		for (UEdGraphNode* Node : Graph->Nodes)
			if (T* Typed = Cast<T>(Node))
				Result.Add(Typed);
		return Result;
	}
	static TArray<TSharedPtr<FJsonValue>> AllGraphNamesJson(UBlueprint* BP);
	static UEdGraphNode* FindNodeByGuid(UBlueprint* BP, const FString& GuidString, UEdGraph** OutGraph = nullptr);
	static bool SaveBlueprintPackage(UBlueprint* BP);

	// ----- Serialization -----
	static TSharedRef<FJsonObject> SerializeBlueprint(UBlueprint* BP);
	static TSharedPtr<FJsonObject> SerializeGraph(UEdGraph* Graph);
	static TSharedPtr<FJsonObject> SerializeNode(UEdGraphNode* Node);
	static TSharedPtr<FJsonObject> SerializePin(UEdGraphPin* Pin);
	static TSharedPtr<FJsonObject> SerializeMaterialExpression(UMaterialExpression* Expression);

	// ----- Type resolution -----
	static UClass* FindClassByName(const FString& ClassName);
	static bool ResolveTypeFromString(const FString& TypeName, FEdGraphPinType& OutPinType, MCPErrorCallback Error);

	// ----- Material helpers -----
	static void EnsureMaterialGraph(UMaterial* Material);
	static bool SaveMaterialPackage(UMaterial* Material);
	static bool SaveGenericPackage(UObject* Asset);

	// ----- Anim blueprint helpers -----
	static UAnimationStateMachineGraph* FindStateMachineGraph(UBlueprint* BP, const FString& GraphName);
	static UAnimStateNode* FindStateByName(UAnimationStateMachineGraph* SMGraph, const FString& StateName, MCPErrorCallback Error);
	static UAnimStateTransitionNode* FindTransition(UAnimationStateMachineGraph* SMGraph, const FString& FromStateName, const FString& ToStateName);

	// ----- Node spawners -----
	static FString NodeSpawnerFullName(UBlueprintNodeSpawner* Spawner);
	static TArray<UBlueprintNodeSpawner*> SearchNodeSpawners(const FString& Query, int32 MaxResults = 0, bool ExactMatch = false, UEdGraph* GraphFilter = nullptr);

	// ----- Property population -----
	static FString PropertyNameToJsonKey(const FString& PropName);
	static bool PopulateFromJson(UStruct* StructType, void* Container, const TSharedPtr<FJsonValue>& JsonValue, MCPErrorCallback Error);
	static bool PopulateFromJson(UStruct* StructType, void* Container, const FJsonObject* Json, MCPErrorCallback Error);

private:
	static FString SetPropertyFromJson(void* Container, FProperty* Prop, const FString& FieldName, const FJsonObject* Json);
};