// Copyright Epic Games, Inc. All Rights Reserved.

#include "PropertyEditorUtils.h"
#include "PropertyPathHelpers.h"

namespace PropertyEditorUtils
{
	void GetPropertyOptions(TArray<UObject*>& InOutContainers, FString& InOutPropertyPath,
		TArray<TSharedPtr<FString>>& InOutOptions)
	{
		// Check for external function references
		if (InOutPropertyPath.Contains(TEXT(".")))
		{
			InOutContainers.Empty();
			UFunction* GetOptionsFunction = FindObject<UFunction>(nullptr, *InOutPropertyPath, true);

			if (ensureMsgf(GetOptionsFunction && GetOptionsFunction->HasAnyFunctionFlags(EFunctionFlags::FUNC_Static), TEXT("Invalid GetOptions: %s"), *InOutPropertyPath))
			{
				UObject* GetOptionsCDO = GetOptionsFunction->GetOuterUClass()->GetDefaultObject();
				GetOptionsFunction->GetName(InOutPropertyPath);
				InOutContainers.Add(GetOptionsCDO);
			}
		}

		if (InOutContainers.Num() > 0)
		{
			TArray<FString> OptionIntersection;
			TSet<FString> OptionIntersectionSet;

			for (UObject* Target : InOutContainers)
			{
				TArray<FString> StringOptions;
				{
					FEditorScriptExecutionGuard ScriptExecutionGuard;

					FCachedPropertyPath Path(InOutPropertyPath);
					if (!PropertyPathHelpers::GetPropertyValue(Target, Path, StringOptions))
					{
						TArray<FName> NameOptions;
						if (PropertyPathHelpers::GetPropertyValue(Target, Path, NameOptions))
						{
							Algo::Transform(NameOptions, StringOptions, [](const FName& InName) { return InName.ToString(); });
						}
					}
				}

				// If this is the first time there won't be any options.
				if (OptionIntersection.Num() == 0)
				{
					OptionIntersection = StringOptions;
					OptionIntersectionSet = TSet<FString>(StringOptions);
				}
				else
				{
					TSet<FString> StringOptionsSet(StringOptions);
					OptionIntersectionSet = StringOptionsSet.Intersect(OptionIntersectionSet);
					OptionIntersection.RemoveAll([&OptionIntersectionSet](const FString& Option){ return !OptionIntersectionSet.Contains(Option); });
				}

				// If we're out of possible intersected options, we can stop.
				if (OptionIntersection.Num() == 0)
				{
					break;
				}
			}

			Algo::Transform(OptionIntersection, InOutOptions, [](const FString& InString) { return MakeShared<FString>(InString); });
		}
	}
}