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

#include "ModelingToolTargetUtil.h"

#include "ToolTargets/ToolTarget.h"
#include "TargetInterfaces/MaterialProvider.h"
#include "TargetInterfaces/MeshDescriptionCommitter.h"
#include "TargetInterfaces/MeshDescriptionProvider.h"
#include "TargetInterfaces/PrimitiveComponentBackedTarget.h"
#include "TargetInterfaces/DynamicMeshSource.h"

#include "ModelingObjectsCreationAPI.h"

#include "Components/PrimitiveComponent.h"
#include "Components/StaticMeshComponent.h"
#include "GameFramework/Volume.h"
#include "Components/DynamicMeshComponent.h"

#include "MeshConversionOptions.h"
#include "MeshDescriptionToDynamicMesh.h"
#include "DynamicMeshToMeshDescription.h"

#define LOCTEXT_NAMESPACE "ModelingToolTargetUtil"

using namespace UE::Geometry;

AActor* UE::ToolTarget::GetTargetActor(UToolTarget* Target)
{
	IPrimitiveComponentBackedTarget* TargetComponent = Cast<IPrimitiveComponentBackedTarget>(Target);
	if (TargetComponent)
	{
		return TargetComponent->GetOwnerActor();
	}
	ensure(false);
	return nullptr;
}

UPrimitiveComponent* UE::ToolTarget::GetTargetComponent(UToolTarget* Target)
{
	IPrimitiveComponentBackedTarget* TargetComponent = Cast<IPrimitiveComponentBackedTarget>(Target);
	if (TargetComponent)
	{
		return TargetComponent->GetOwnerComponent();
	}
	ensure(false);
	return nullptr;
}

bool UE::ToolTarget::HideSourceObject(UToolTarget* Target)
{
	IPrimitiveComponentBackedTarget* TargetComponent = Cast<IPrimitiveComponentBackedTarget>(Target);
	if (TargetComponent)
	{
		TargetComponent->SetOwnerVisibility(false);
		return true;
	}
	ensure(false);
	return false;
}

bool UE::ToolTarget::ShowSourceObject(UToolTarget* Target)
{
	IPrimitiveComponentBackedTarget* TargetComponent = Cast<IPrimitiveComponentBackedTarget>(Target);
	if (TargetComponent)
	{
		TargetComponent->SetOwnerVisibility(true);
		return true;
	}
	ensure(false);
	return false;
}


bool UE::ToolTarget::SetSourceObjectVisible(UToolTarget* Target, bool bVisible)
{
	if (bVisible)
	{
		return ShowSourceObject(Target);
	}
	else
	{
		return HideSourceObject(Target);
	}
}


FTransform3d UE::ToolTarget::GetLocalToWorldTransform(UToolTarget* Target)
{
	IPrimitiveComponentBackedTarget* TargetComponent = Cast<IPrimitiveComponentBackedTarget>(Target);
	if (TargetComponent)
	{
		return (FTransform3d)TargetComponent->GetWorldTransform();
	}
	ensure(false);
	return FTransform3d();
}

FComponentMaterialSet UE::ToolTarget::GetMaterialSet(UToolTarget* Target, bool bPreferAssetMaterials)
{
	FComponentMaterialSet MaterialSet;
	IMaterialProvider* MaterialProvider = Cast<IMaterialProvider>(Target);
	if (ensure(MaterialProvider))
	{
		MaterialProvider->GetMaterialSet(MaterialSet, bPreferAssetMaterials);
	}
	return MaterialSet;
}


bool UE::ToolTarget::CommitMaterialSetUpdate(
	UToolTarget* Target,
	const FComponentMaterialSet& UpdatedMaterials,
	bool bApplyToAsset)
{
	IMaterialProvider* MaterialProvider = Cast<IMaterialProvider>(Target);
	if (MaterialProvider)
	{
		return MaterialProvider->CommitMaterialSetUpdate(UpdatedMaterials, bApplyToAsset);
	}
	return false;
}



const FMeshDescription* UE::ToolTarget::GetMeshDescription(UToolTarget* Target)
{
	static FMeshDescription EmptyMeshDescription;

	IMeshDescriptionProvider* MeshDescriptionProvider = Cast<IMeshDescriptionProvider>(Target);
	if (MeshDescriptionProvider)
	{
		return MeshDescriptionProvider->GetMeshDescription();
	}
	ensure(false);
	return &EmptyMeshDescription;
}


FMeshDescription UE::ToolTarget::GetMeshDescriptionCopy(UToolTarget* Target, bool bWantMeshTangents)
{
	IMeshDescriptionProvider* MeshDescriptionProvider = Cast<IMeshDescriptionProvider>(Target);
	if (MeshDescriptionProvider)
	{
		FMeshDescription NewMeshDescription = *MeshDescriptionProvider->GetMeshDescription();
		if (bWantMeshTangents)
		{
			MeshDescriptionProvider->CalculateAutoGeneratedAttributes(NewMeshDescription);
		}
		return NewMeshDescription;
	}
	ensure(false);
	return FMeshDescription();
}


FDynamicMesh3 UE::ToolTarget::GetDynamicMeshCopy(UToolTarget* Target, bool bWantMeshTangents)
{
	IPersistentDynamicMeshSource* DynamicMeshSource = Cast<IPersistentDynamicMeshSource>(Target);
	if (DynamicMeshSource)
	{
		UDynamicMesh* DynamicMesh = DynamicMeshSource->GetDynamicMeshContainer();
		FDynamicMesh3 Mesh;
		DynamicMesh->ProcessMesh([&](const FDynamicMesh3& ReadMesh) { Mesh = ReadMesh; });
		return Mesh;
	}

	IMeshDescriptionProvider* MeshDescriptionProvider = Cast<IMeshDescriptionProvider>(Target);
	FDynamicMesh3 Mesh(EMeshComponents::FaceGroups);
	Mesh.EnableAttributes();
	if (MeshDescriptionProvider)
	{
		FMeshDescriptionToDynamicMesh Converter;
		if (bWantMeshTangents)
		{
			// Currently to auto-calculate attributes we must make a copy, because they are written
			// directly to the input mesh
			FMeshDescription MeshDescriptionCopy( *MeshDescriptionProvider->GetMeshDescription() );
			MeshDescriptionProvider->CalculateAutoGeneratedAttributes(MeshDescriptionCopy);
			Converter.Convert(&MeshDescriptionCopy, Mesh, bWantMeshTangents);
		}
		else
		{
			Converter.Convert(MeshDescriptionProvider->GetMeshDescription(), Mesh, bWantMeshTangents);
		}

		return Mesh;
	}

	ensure(false);
	return Mesh;
}


UE::ToolTarget::EDynamicMeshUpdateResult UE::ToolTarget::CommitMeshDescriptionUpdate(UToolTarget* Target, const FMeshDescription* UpdatedMesh, const FComponentMaterialSet* UpdatedMaterials)
{
	IMeshDescriptionCommitter* MeshDescriptionCommitter = Cast<IMeshDescriptionCommitter>(Target);
	if (!ensure(MeshDescriptionCommitter))
	{
		return EDynamicMeshUpdateResult::Failed;
	}

	if (UpdatedMaterials != nullptr)
	{
		CommitMaterialSetUpdate(Target, *UpdatedMaterials, true);
	}

	EDynamicMeshUpdateResult Result = EDynamicMeshUpdateResult::Failed;
	MeshDescriptionCommitter->CommitMeshDescription([UpdatedMesh, &Result](const IMeshDescriptionCommitter::FCommitterParams& CommitParams)
	{
		*CommitParams.MeshDescriptionOut = *UpdatedMesh;
		Result = EDynamicMeshUpdateResult::Ok;
	});
	return Result;
}




UE::ToolTarget::EDynamicMeshUpdateResult UE::ToolTarget::CommitDynamicMeshUpdate(
	UToolTarget* Target, const FDynamicMesh3& UpdatedMesh, 
	bool bHaveModifiedTopology,
	const FConversionToMeshDescriptionOptions& ConversionOptions,
	const FComponentMaterialSet* UpdatedMaterials)
{
	if (UpdatedMaterials != nullptr)
	{
		CommitMaterialSetUpdate(Target, *UpdatedMaterials, true);
	}

	IPersistentDynamicMeshSource* DynamicMeshSource = Cast<IPersistentDynamicMeshSource>(Target);
	if (DynamicMeshSource)
	{
		UDynamicMesh* DynamicMesh = DynamicMeshSource->GetDynamicMeshContainer();
		TUniquePtr<FDynamicMesh3> CurrentMesh = DynamicMesh->ExtractMesh();
		TSharedPtr<FDynamicMesh3> CurrentMeshShared(CurrentMesh.Release());

		DynamicMesh->EditMesh([&](FDynamicMesh3& EditMesh) { EditMesh = UpdatedMesh; });

		TSharedPtr<FDynamicMesh3> NewMeshShared = MakeShared<FDynamicMesh3>();
		DynamicMesh->ProcessMesh([&](const FDynamicMesh3& ReadMesh) { *NewMeshShared = ReadMesh; });

		TUniquePtr<FMeshReplacementChange> ReplaceChange = MakeUnique<FMeshReplacementChange>(CurrentMeshShared, NewMeshShared);
		
		DynamicMeshSource->CommitDynamicMeshChange(MoveTemp(ReplaceChange), LOCTEXT("CommitDynamicMeshUpdate_MeshSource", "Edit Mesh"));


		// todo support bModifiedTopology flag?
		return EDynamicMeshUpdateResult::Ok;
	}

	IMeshDescriptionCommitter* MeshDescriptionCommitter = Cast<IMeshDescriptionCommitter>(Target);
	if (MeshDescriptionCommitter)
	{
		EDynamicMeshUpdateResult Result = EDynamicMeshUpdateResult::Failed;
		MeshDescriptionCommitter->CommitMeshDescription([&](const IMeshDescriptionCommitter::FCommitterParams& CommitParams)
		{
			FMeshDescription* MeshDescription = CommitParams.MeshDescriptionOut;

			FDynamicMeshToMeshDescription Converter(ConversionOptions);
			if (!bHaveModifiedTopology)
			{
				Converter.UpdateUsingConversionOptions(&UpdatedMesh, *MeshDescription);
				Result = EDynamicMeshUpdateResult::Ok;
			}
			else
			{
				Converter.Convert(&UpdatedMesh, *MeshDescription);
				Result = EDynamicMeshUpdateResult::Ok;
			}
		});
		return Result;
	}

	ensure(false);
	return EDynamicMeshUpdateResult::Failed;
}





UE::ToolTarget::EDynamicMeshUpdateResult UE::ToolTarget::CommitDynamicMeshUVUpdate(UToolTarget* Target, const UE::Geometry::FDynamicMesh3* UpdatedMesh)
{
	IPersistentDynamicMeshSource* DynamicMeshSource = Cast<IPersistentDynamicMeshSource>(Target);
	if (DynamicMeshSource)
	{
		// todo actually only update UVs? 
		UDynamicMesh* DynamicMesh = DynamicMeshSource->GetDynamicMeshContainer();
		DynamicMesh->EditMesh([&](FDynamicMesh3& EditMesh) { EditMesh = *UpdatedMesh; });
		return EDynamicMeshUpdateResult::Ok;
	}


	IMeshDescriptionCommitter* MeshDescriptionCommitter = Cast<IMeshDescriptionCommitter>(Target);
	if (!ensure(MeshDescriptionCommitter))
	{
		return EDynamicMeshUpdateResult::Failed;
	}

	EDynamicMeshUpdateResult Result = EDynamicMeshUpdateResult::Failed;
	MeshDescriptionCommitter->CommitMeshDescription([UpdatedMesh, &Result](const IMeshDescriptionCommitter::FCommitterParams& CommitParams)
	{
		FMeshDescription* MeshDescription = CommitParams.MeshDescriptionOut;

		bool bVerticesOnly = false;
		bool bAttributesOnly = true;
		if (FDynamicMeshToMeshDescription::HaveMatchingElementCounts(UpdatedMesh, MeshDescription, bVerticesOnly, bAttributesOnly))
		{
			FDynamicMeshToMeshDescription Converter;
			Converter.UpdateAttributes(UpdatedMesh, *MeshDescription, false, false, true/*update uvs*/);
			Result = EDynamicMeshUpdateResult::Ok;
		}
		else
		{
			// must have been duplicate tris in the mesh description; we can't count on 1-to-1 mapping of TriangleIDs.  Just convert 
			FDynamicMeshToMeshDescription Converter;
			Converter.Convert(UpdatedMesh, *MeshDescription);
			Result = EDynamicMeshUpdateResult::Ok_ForcedFullUpdate;
		}
	});
	return Result;
}



bool UE::ToolTarget::ConfigureCreateMeshObjectParams(UToolTarget* SourceTarget, FCreateMeshObjectParams& DerivedParamsOut)
{
	IPrimitiveComponentBackedTarget* ComponentTarget = Cast<IPrimitiveComponentBackedTarget>(SourceTarget);
	if (ComponentTarget)
	{
		if (Cast<UStaticMeshComponent>(ComponentTarget->GetOwnerComponent()) != nullptr)
		{
			DerivedParamsOut.TypeHint = ECreateObjectTypeHint::StaticMesh;
			return true;
		}

		if (Cast<UDynamicMeshComponent>(ComponentTarget->GetOwnerComponent()) != nullptr)
		{
			DerivedParamsOut.TypeHint = ECreateObjectTypeHint::DynamicMeshActor;
			return true;
		}

		AVolume* VolumeActor = Cast<AVolume>(ComponentTarget->GetOwnerActor());
		if (VolumeActor != nullptr)
		{
			DerivedParamsOut.TypeHint = ECreateObjectTypeHint::Volume;
			DerivedParamsOut.TypeHintClass = VolumeActor->GetClass();
			return true;
		}
	}
	return false;
}



#undef LOCTEXT_NAMESPACE