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

#include "GetGroomAssetNode.h"
#include "GroomEdit.h"
#include "GroomInstance.h"
#include "GroomCollectionFacades.h"
#include "Dataflow/DataflowInputOutput.h"
#include "Dataflow/DataflowObjectInterface.h"

#include UE_INLINE_GENERATED_CPP_BY_NAME(GetGroomAssetNode)

namespace UE::Groom::Private
{
	template<typename FacadeType>
	FORCEINLINE const UGroomAsset* BuildGroomCollection(Dataflow::FContext& Context, const UGroomAsset* NodeGroom, FManagedArrayCollection& GroomCollection, FEditableGroom& EditGroom)
	{
		const UGroomAsset* GroomAsset = NodeGroom;
		if (!GroomAsset)
		{
			if (const Dataflow::FEngineContext* EngineContext = Context.AsType<Dataflow::FEngineContext>())
			{
				GroomAsset = Cast<UGroomAsset>(EngineContext->Owner);
			}
		}

		if (GroomAsset)
		{
			ConvertFromGroomAsset(const_cast<UGroomAsset*>(GroomAsset), &EditGroom, false, false, false);

			TArray<FVector3f> PointRestPositions;
			TArray<int32> ObjectCurveOffsets;
			TArray<int32> CurvePointOffsets;
			TArray<FString> ObjectGroupNames;

			uint32 GroupIndex = 0;
			for(FEditableGroomGroup& GroomGroup : EditGroom.Groups)
			{
				
				for( const typename FacadeType::FEditableType& EditType : FacadeType::GetEditableGroom(GroomGroup))
				{
					for(auto& GuidePoint : EditType.ControlPoints)
					{
						PointRestPositions.Add(GuidePoint.Position);
					}
					CurvePointOffsets.Add(PointRestPositions.Num());
				}
				ObjectCurveOffsets.Add(CurvePointOffsets.Num());
				
				const FString GroupName = GroomAsset->GetName() + TEXT("_") + FacadeType::GroupPrefix.ToString();
				ObjectGroupNames.Add(GroupName);
				++GroupIndex;
			}
			FacadeType CurvesFacade(GroomCollection);
			CurvesFacade.InitGroomCollection(PointRestPositions, CurvePointOffsets, ObjectCurveOffsets, ObjectGroupNames);

			const FString GroomName = GroomAsset->GetName();

			return GroomAsset;
		}
		return nullptr;
	}
}

void FGetGroomAssetDataflowNode::Evaluate(UE::Dataflow::FContext& Context, const FDataflowOutput* Out) const
{
	if (Out->IsA<FManagedArrayCollection>(&Collection))
	{
		FManagedArrayCollection GroomCollection;
		FEditableGroom EditGroom;
		const UGroomAsset* LocalGroom = nullptr;
		if(CurvesType == EGroomCollectionType::Guides)
		{
			LocalGroom = UE::Groom::Private::BuildGroomCollection<UE::Groom::FGroomGuidesFacade>(
				Context, GroomAsset, GroomCollection, EditGroom);
		}
		else if(CurvesType == EGroomCollectionType::Strands)
		{
			LocalGroom = UE::Groom::Private::BuildGroomCollection<UE::Groom::FGroomStrandsFacade>(
				Context, GroomAsset, GroomCollection, EditGroom);
		}

		if(LocalGroom)
		{
			TArray<int32> ObjectPointSamples, CurveStrandIndices;
			const TArray<FHairGroupsPhysics>& GroupsPhysics = LocalGroom->GetHairGroupsPhysics();
			for(const FHairGroupsPhysics& GroupPhysics : GroupsPhysics)
			{
				ObjectPointSamples.Add(static_cast<uint8>(GroupPhysics.StrandsParameters.StrandsSize));
			}
				
			UE::Groom::FGroomGuidesFacade GuidesFacade(GroomCollection);
			if(GroomCollection.NumElements(UE::Groom::FGroomGuidesFacade::ObjectsGroup) == 0)
			{
				GroomCollection.AddElements(ObjectPointSamples.Num(), UE::Groom::FGroomGuidesFacade::ObjectsGroup);
			}
			GuidesFacade.SetObjectPointSamples(ObjectPointSamples);
		}
		SetValue(Context, MoveTemp(GroomCollection), &Collection);
	}
}

TArray<UE::Dataflow::FRenderingParameter> FGetGroomAssetDataflowNode::GetRenderParametersImpl() const
{
	if(CurvesType == EGroomCollectionType::Guides)
	{
		return { {TEXT("GuidesRender"), FName("FGroomCollection"), {TEXT("Collection")}}};
	}
	else
	{
		return { {TEXT("StrandsRender"), FName("FGroomCollection"), {TEXT("Collection")}}};
	}
}