// ©2023 Batty Bovine Productions, LLC. All Rights Reserved.

#include "FConnectionDrawingPolicy_ComboActionGraph.h"

#include "ComboInputEditor.h"
#include "Ed/EdComboActionGraphEdge.h"
#include "Ed/EdComboActionGraphNode.h"
#include "Settings/ComboActionGraphEditorSettings.h"
#include "Settings/FComboActionGraphEditorStyle.h"

DEFINE_LOG_CATEGORY(LogConnectionDrawingPolicy_ComboActionGraph);


FConnectionDrawingPolicy_ComboActionGraph::FConnectionDrawingPolicy_ComboActionGraph(int32 InBackLayerID, int32 InFrontLayerID, float ZoomFactor, const FSlateRect &InClippingRect, FSlateWindowElementList &InDrawElements, UEdGraph *InGraphObj)
	: FKismetConnectionDrawingPolicy(InBackLayerID, InFrontLayerID, ZoomFactor, InClippingRect, InDrawElements, InGraphObj)
	  , GraphObj(InGraphObj)
{
	if (const UComboActionGraphEditorSettings* GraphEditorSettings = GetMutableDefault<UComboActionGraphEditorSettings>())
	{
		FComboInputEditorModule &ComboInputEditorModule = FComboInputEditorModule::Get();
		switch (GraphEditorSettings->GetArrowType())
		{
			case EComboActionArrowType::SimpleArrow:
				ArrowImage = ComboInputEditorModule.ComboActionGraphEditorStyleSet->GetBrush(TEXT("MDSStyleSet.Graph.SimpleArrow"));
				break;
			case EComboActionArrowType::HollowArrow:
				ArrowImage = ComboInputEditorModule.ComboActionGraphEditorStyleSet->GetBrush(TEXT("MDSStyleSet.Graph.HollowArrow"));
				break;
			case EComboActionArrowType::FancyArrow:
				ArrowImage = ComboInputEditorModule.ComboActionGraphEditorStyleSet->GetBrush(TEXT("MDSStyleSet.Graph.FancyArrow"));
				break;
			case EComboActionArrowType::Bubble:
				ArrowImage = ComboInputEditorModule.ComboActionGraphEditorStyleSet->GetBrush(TEXT("MDSStyleSet.Graph.Bubble"));
				break;
			case EComboActionArrowType::None:
			default:
				ArrowImage = nullptr;
		}
	}
	else
	{
		ArrowImage = FAppStyle::GetBrush( TEXT("GenericPlay") );
	}
	
	ArrowRadius = ArrowImage ? ArrowImage->ImageSize * ZoomFactor * 0.5f : FVector2D(0.f);
	MidpointImage = nullptr;
	MidpointRadius = FVector2D::ZeroVector;
	HoverDeemphasisDarkFraction = 0.8f;

	BubbleImage = FAppStyle::GetBrush( TEXT("Graph.Arrow") );
}

void FConnectionDrawingPolicy_ComboActionGraph::DetermineWiringStyle(UEdGraphPin *OutputPin, UEdGraphPin *InputPin, FConnectionParams &Params)
{
	Params.AssociatedPin1 = OutputPin;
	Params.AssociatedPin2 = InputPin;

	const UComboActionGraphEditorSettings *MounteaDialogueGraphEditorSettings = GetDefault<UComboActionGraphEditorSettings>();
	if (MounteaDialogueGraphEditorSettings)
	{
		Params.WireThickness = MounteaDialogueGraphEditorSettings->GetWireWidth();
	}
	else
	{
		Params.WireThickness = 1.f;
	}

	const bool bDeemphasizeUnhoveredPins = HoveredPins.Num() > 0;
	if (bDeemphasizeUnhoveredPins)
	{
		ApplyHoverDeemphasis(OutputPin, InputPin, /*inout*/ Params.WireThickness, /*inout*/ Params.WireColor);
	}
}

void FConnectionDrawingPolicy_ComboActionGraph::Draw(TMap<TSharedRef<SWidget>, FArrangedWidget> &InPinGeometries, FArrangedChildren &ArrangedNodes)
{
	// Build an acceleration structure to quickly find geometry for the nodes
	NodeWidgetMap.Empty();
	for (int32 NodeIndex = 0; NodeIndex < ArrangedNodes.Num(); ++NodeIndex)
	{
		FArrangedWidget& CurWidget = ArrangedNodes[NodeIndex];
		TSharedRef<SGraphNode> ChildNode = StaticCastSharedRef<SGraphNode>(CurWidget.Widget);
		NodeWidgetMap.Add(ChildNode->GetNodeObj(), NodeIndex);
	}

	// Now draw
	FConnectionDrawingPolicy::Draw(InPinGeometries, ArrangedNodes);
}

void FConnectionDrawingPolicy_ComboActionGraph::DrawSplineWithArrow(const FGeometry &StartGeom, const FGeometry &EndGeom, const FConnectionParams &Params)
{
	// Get a reasonable seed point (halfway between the boxes)
	const FVector2D StartCenter = FGeometryHelper::CenterOf(StartGeom);
	const FVector2D EndCenter = FGeometryHelper::CenterOf(EndGeom);
	const FVector2D SeedPoint = (StartCenter + EndCenter) * 0.5f;

	// Find the (approximate) closest points between the two boxes
	const FVector2D StartAnchorPoint = FGeometryHelper::FindClosestPointOnGeom(StartGeom, SeedPoint);
	const FVector2D EndAnchorPoint = FGeometryHelper::FindClosestPointOnGeom(EndGeom, SeedPoint);

	this->DrawSplineWithArrow(StartAnchorPoint, EndAnchorPoint, Params);
}

void FConnectionDrawingPolicy_ComboActionGraph::DrawSplineWithArrow(const FVector2D &StartPoint, const FVector2D &EndPoint, const FConnectionParams &Params)
{
	// bUserFlag1 indicates that we need to reverse the direction of connection (used by debugger)
	const FVector2D &P0 = Params.bUserFlag1 ? EndPoint : StartPoint;
	const FVector2D &P1 = Params.bUserFlag1 ? StartPoint : EndPoint;

	UE_LOG(LogConnectionDrawingPolicy_ComboActionGraph, Verbose, TEXT("%s I %s"), *P0.ToString(), *P1.ToString());
	
	FConnectionParams NewParams = Params;
	//NewParams.bDrawBubbles = true;
	
	if (const UComboActionGraphEditorSettings *MounteaDialogueGraphEditorSettings = GetMutableDefault<UComboActionGraphEditorSettings>())
	{
		NewParams.WireThickness = MounteaDialogueGraphEditorSettings->GetWireWidth();
	}
	
	Internal_DrawLineWithArrow(P0, P1, NewParams);
}

void FConnectionDrawingPolicy_ComboActionGraph::DrawPreviewConnector(const FGeometry &PinGeometry, const FVector2D &StartPoint, const FVector2D &EndPoint, UEdGraphPin* Pin)
{
	FConnectionParams Params;
	DetermineWiringStyle(Pin, nullptr, /*inout*/ Params);

	if (Pin->Direction == EEdGraphPinDirection::EGPD_Output)
	{
		DrawSplineWithArrow(FGeometryHelper::FindClosestPointOnGeom(PinGeometry, EndPoint), EndPoint, Params);
	}
	else
	{
		DrawSplineWithArrow(FGeometryHelper::FindClosestPointOnGeom(PinGeometry, StartPoint), StartPoint, Params);
	}
}

FVector2D FConnectionDrawingPolicy_ComboActionGraph::ComputeSplineTangent(const FVector2D &Start, const FVector2D &End) const
{
	const FVector2D Delta = End - Start;
	const FVector2D NormDelta = Delta.GetSafeNormal();

	return NormDelta;
}

void FConnectionDrawingPolicy_ComboActionGraph::DetermineLinkGeometry(FArrangedChildren &ArrangedNodes, TSharedRef<SWidget> &OutputPinWidget, UEdGraphPin *OutputPin, UEdGraphPin *InputPin, FArrangedWidget *&StartWidgetGeometry, FArrangedWidget *&EndWidgetGeometry)
{
	if (UEdComboActionGraphEdge *EdgeNode = Cast<UEdComboActionGraphEdge>(InputPin->GetOwningNode()))
	{
		UEdComboActionGraphNode* Start = EdgeNode->GetStartNode();
		UEdComboActionGraphNode* End = EdgeNode->GetEndNode();
		if (Start != nullptr && End != nullptr)
		{
			int32* StartNodeIndex = NodeWidgetMap.Find(Start);
			int32* EndNodeIndex = NodeWidgetMap.Find(End);
			if (StartNodeIndex != nullptr && EndNodeIndex != nullptr)
			{
				StartWidgetGeometry = &(ArrangedNodes[*StartNodeIndex]);
				EndWidgetGeometry = &(ArrangedNodes[*EndNodeIndex]);
			}
		}
	}
	else
	{
		StartWidgetGeometry = PinGeometries->Find(OutputPinWidget);

		if (TSharedPtr<SGraphPin>* pTargetWidget = PinToPinWidgetMap.Find(InputPin))
		{
			TSharedRef<SGraphPin> InputWidget = (*pTargetWidget).ToSharedRef();
			EndWidgetGeometry = PinGeometries->Find(InputWidget);
		}
	}
}

void FConnectionDrawingPolicy_ComboActionGraph::Internal_DrawLineWithArrow(const FVector2D &StartAnchorPoint, const FVector2D &EndAnchorPoint, const FConnectionParams &Params)
{
	const float LineSeparationAmount = 4.5f;

	const FVector2D DeltaPos = EndAnchorPoint - StartAnchorPoint;
	const FVector2D UnitDelta = DeltaPos.GetSafeNormal();
	const FVector2D Normal = FVector2D(DeltaPos.Y, -DeltaPos.X).GetSafeNormal();

	// Come up with the final start/end points
	const FVector2D DirectionBias = Normal * LineSeparationAmount;
	const FVector2D LengthBias = ArrowRadius.X * UnitDelta;
	const FVector2D StartPoint = StartAnchorPoint + DirectionBias + LengthBias;
	const FVector2D EndPoint = EndAnchorPoint + DirectionBias - LengthBias;

	// Draw a line/spline
	DrawConnection(WireLayerID, StartPoint, EndPoint, Params);
	
	// Draw the arrow
	if (ArrowImage)
	{
		const FVector2D ArrowDrawPos = EndPoint - ArrowRadius;
		const float AngleInRadians = FMath::Atan2(DeltaPos.Y, DeltaPos.X);

		FSlateDrawElement::MakeRotatedBox(
			DrawElementsList,
			ArrowLayerID,
			FPaintGeometry(ArrowDrawPos, ArrowImage->ImageSize * ZoomFactor, ZoomFactor),
			ArrowImage,
			ESlateDrawEffect::None,
			AngleInRadians,
			TOptional<FVector2D>(),
			FSlateDrawElement::RelativeToElement,
			Params.WireColor
		);
	}
}