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

#include "DatasmithSketchUpUtils.h"
#include "DatasmithSketchUpCommon.h"
#include "DatasmithSketchUpString.h"
#include "DatasmithSketchUpSummary.h"

#include "IDatasmithSceneElements.h"

// SketchUp SDK.
#include "DatasmithSketchUpSDKBegins.h"

#include "SketchUpAPI/model/camera.h"
#include "SketchUpAPI/model/component_definition.h"
#include "SketchUpAPI/model/component_instance.h"
#include "SketchUpAPI/model/drawing_element.h"
#include "SketchUpAPI/model/edge.h"
#include "SketchUpAPI/model/entities.h"
#include "SketchUpAPI/model/entity.h"
#include "SketchUpAPI/model/face.h"
#include "SketchUpAPI/model/geometry.h"
#include "SketchUpAPI/model/group.h"
#include "SketchUpAPI/model/layer.h"
#include "SketchUpAPI/model/material.h"
#include "SketchUpAPI/model/mesh_helper.h"
#include "SketchUpAPI/model/model.h"
#include "SketchUpAPI/model/scene.h"
#include "SketchUpAPI/model/texture.h"
#include "SketchUpAPI/model/uv_helper.h"

#include "DatasmithSketchUpSDKCeases.h"

// Imath third party library.
#include "Imath/ImathMatrixAlgo.h"



using namespace DatasmithSketchUp;

DatasmithSketchUp::FEntityIDType DatasmithSketchUpUtils::GetEntityID(SUEntityRef InEntityRef)
{
	int32 Id = 0;
	SUEntityGetID(InEntityRef, &Id); // we can ignore the returned SU_RESULT
	return FEntityIDType{ Id };
}

SULayerRef DatasmithSketchUpUtils::GetEffectiveLayer(
	SUComponentInstanceRef InComponentInstanceRef, // valid SketckUp component instance
	SULayerRef             InInheritedLayerRef
)
{
	// Retrieve the SketckUp component instance layer.
	SULayerRef SComponentInstanceLayerRef = SU_INVALID;
	SUDrawingElementGetLayer(SUComponentInstanceToDrawingElement(InComponentInstanceRef), &SComponentInstanceLayerRef); // we can ignore the returned SU_RESULT

	// Retrieve the SketchUp component instance layer name.
	FString SComponentInstanceLayerName;
	SComponentInstanceLayerName = SuGetString(SULayerGetName, SComponentInstanceLayerRef);

	// Return the effective layer.
	return SComponentInstanceLayerName.Equals(TEXT("Layer0")) ? InInheritedLayerRef : SComponentInstanceLayerRef;
}

FComponentDefinitionIDType DatasmithSketchUpUtils::GetComponentID(
	SUComponentDefinitionRef InComponentDefinitionRef
)
{
	return GetEntityID(SUComponentDefinitionToEntity(InComponentDefinitionRef));
}

FComponentInstanceIDType DatasmithSketchUpUtils::GetComponentInstanceID(
	SUComponentInstanceRef InComponentInstanceRef
)
{
	return GetEntityID(SUComponentInstanceToEntity(InComponentInstanceRef));
}

FComponentInstanceIDType DatasmithSketchUpUtils::GetGroupID(
	SUGroupRef InGroupRef
)
{
	return GetEntityID(SUGroupToEntity(InGroupRef));
}



int64 DatasmithSketchUpUtils::GetComponentPID(
	SUComponentInstanceRef InComponentInstanceRef
)
{
	// Get the SketckUp component instance persistent ID.
	int64 SPersistentID = 0;
	SUEntityGetPersistentID(SUComponentInstanceToEntity(InComponentInstanceRef), &SPersistentID); // we can ignore the returned SU_RESULT

	return SPersistentID;
}

FEntityIDType DatasmithSketchUpUtils::GetSceneID(
	SUSceneRef InSceneRef
)
{
	return GetEntityID(SUSceneToEntity(InSceneRef));;
}

FEntityIDType  DatasmithSketchUpUtils::GetMaterialID(
	SUMaterialRef InMaterialRef
)
{
	return GetEntityID(SUMaterialToEntity(InMaterialRef));
}


int32 DatasmithSketchUpUtils::GetFaceID(
	SUFaceRef InFaceRef
)
{
	// Get the SketckUp face ID.
	int32 SFaceID = 0;
	SUEntityGetID(SUFaceToEntity(InFaceRef), &SFaceID); // we can ignore the returned SU_RESULT

	return SFaceID;
}

int32 DatasmithSketchUpUtils::GetEdgeID(
	SUEdgeRef InEdgeRef
)
{
	// Get the SketckUp edge ID.
	int32 SEdgeID = 0;
	SUEntityGetID(SUEdgeToEntity(InEdgeRef), &SEdgeID); // we can ignore the returned SU_RESULT

	return SEdgeID;
}

bool DatasmithSketchUpUtils::IsVisible(
	SUComponentInstanceRef InSComponentInstanceRef,
	SULayerRef             InSEffectiveLayerRef
)
{
	// Get the flag indicating whether or not the SketchUp component instance is hidden.
	bool bSComponentInstanceHidden = false;
	SUDrawingElementGetHidden(SUComponentInstanceToDrawingElement(InSComponentInstanceRef), &bSComponentInstanceHidden); // we can ignore the returned SU_RESULT

	// Get the flag indicating whether or not the SketchUp component instance effective layer is visible.
	bool bSEffectiveLayerVisible = true;
	SULayerGetVisibility(InSEffectiveLayerRef, &bSEffectiveLayerVisible); // we can ignore the returned SU_RESULT

	return (!bSComponentInstanceHidden && bSEffectiveLayerVisible);
}

bool DatasmithSketchUpUtils::IsVisible(
	SUFaceRef  InFaceRef
)
{
	// Get the flag indicating whether or not the SketchUp face is hidden.
	bool bFaceHidden = false;
	SUDrawingElementGetHidden(SUFaceToDrawingElement(InFaceRef), &bFaceHidden); // we can ignore the returned SU_RESULT

	// Retrieve the SketckUp face layer.
	SULayerRef SFaceLayerRef = SU_INVALID;
	SUDrawingElementGetLayer(SUFaceToDrawingElement(InFaceRef), &SFaceLayerRef); // we can ignore the returned SU_RESULT

	// Retrieve the SketchUp face layer name.
	FString SFaceLayerName = SuGetString(SULayerGetName, SFaceLayerRef);

	// Get the flag indicating whether or not the SketchUp face effective layer is visible.
	bool bSFaceEffectiveLayerVisible = true;
	SULayerGetVisibility(SFaceLayerRef, &bSFaceEffectiveLayerVisible); // we can ignore the returned SU_RESULT

	return (!bFaceHidden && bSFaceEffectiveLayerVisible);
}

SUMaterialRef DatasmithSketchUpUtils::GetMaterial(
	SUComponentInstanceRef InComponentInstanceRef
)
{
	// Retrieve the SketckUp drawing element material.
	SUMaterialRef SMaterialRef = SU_INVALID;
	SUDrawingElementGetMaterial(SUComponentInstanceToDrawingElement(InComponentInstanceRef), &SMaterialRef); // we can ignore the returned SU_RESULT

	return SMaterialRef;
}

void DatasmithSketchUpUtils::SetActorTransform(
	TSharedPtr<IDatasmithActorElement> InActorElement,
	SUTransformation const& InWorldTransform
)
{
	// We use Imath::extractAndRemoveScalingAndShear() because FMatrix::ExtractScaling() is deemed unreliable.

	// Set up a scaling and rotation matrix.
	auto& SMatrix = InWorldTransform.values;
	Imath::Matrix44<float> Matrix(float(SMatrix[0]), float(SMatrix[1]), float(SMatrix[2]), 0.0,
		float(SMatrix[4]), float(SMatrix[5]), float(SMatrix[6]), 0.0,
		float(SMatrix[8]), float(SMatrix[9]), float(SMatrix[10]), 0.0,
		0.0, 0.0, 0.0, 1.0);

	// Remove any scaling from the matrix and get the scale vector that was initially present.
	Imath::Vec3<float> Scale;
	Imath::Vec3<float> Shear;
	bool bExtracted = Imath::extractAndRemoveScalingAndShear<float>(Matrix, Scale, Shear, false);

	if (!bExtracted)
	{
		ADD_SUMMARY_LINE(TEXT("WARNING: Actor %ls (%ls) has some zero scaling"), InActorElement->GetName(), InActorElement->GetLabel());
		return;
	}

	if (SMatrix[15] != 1.0)
	{
		// Apply the extra SketchUp uniform scaling factor.
		Scale *= float(SMatrix[15]);
	}

	// Initialize a rotation quaternion with the rotation matrix.
	Imath::Quat<float> Quaternion = Imath::extractQuat<float>(Matrix);

	// Convert the SketchUp right-handed Z-up coordinate rotation into an Unreal left-handed Z-up coordinate rotation.
	// This is done by inverting the X and Z components of the quaternion to mirror the quaternion on the XZ-plane.
	Quaternion.v.x = -Quaternion.v.x;
	Quaternion.v.z = -Quaternion.v.z;
	Quaternion.normalize();

	// Make sure Unreal will be able to handle the rotation quaternion.
	float              Angle = Quaternion.angle();
	Imath::Vec3<float> Axis = Quaternion.axis();
	FQuat Rotation(FVector(Axis.x, Axis.y, Axis.z), Angle);

	ensure(Rotation.IsNormalized());

	// Convert the SketchUp right-handed Z-up coordinate translation into an Unreal left-handed Z-up coordinate translation.
	// To avoid perturbating X, which is forward in Unreal, the handedness conversion is done by flipping the side vector Y.
	// SketchUp uses inches as internal system unit for all 3D coordinates in the model while Unreal uses centimeters.

	FVector3f Translation = DatasmithSketchUpUtils::FromSketchUp::ConvertPosition(SMatrix[12], SMatrix[13], SMatrix[14]);

	// Set the world transform of the Datasmith actor.
	InActorElement->SetTranslation(Translation.X, Translation.Y, Translation.Z, false);
	InActorElement->SetRotation((float)Rotation.X, (float)Rotation.Y, (float)Rotation.Z, (float)Rotation.W, false);
	InActorElement->SetScale(Scale.x, Scale.y, Scale.z, false);
}

SUTransformation DatasmithSketchUpUtils::GetComponentInstanceTransform(SUComponentInstanceRef InComponentInstanceRef, SUTransformation const& InWorldTransform)
{
	// Get the SketchUp component instance transform.
	SUTransformation SComponentInstanceTransform;
	SUComponentInstanceGetTransform(InComponentInstanceRef, &SComponentInstanceTransform); // we can ignore the returned SU_RESULT

	// Compute the world transform of the SketchUp component instance.
	SUTransformation SComponentInstanceWorldTransform;
	SUTransformationMultiply(&InWorldTransform, &SComponentInstanceTransform, &SComponentInstanceWorldTransform); // we can ignore the returned SU_RESULT
	return SComponentInstanceWorldTransform;
}