#include "SkillTreeConnectionsWidget.h"
#include "SkillTreeComponent.h"
#include "Blueprint/WidgetTree.h"
#include "Components/PanelWidget.h"
#include "Rendering/DrawElements.h"
#include "Blueprint/WidgetLayoutLibrary.h"

USkillTreeConnectionsWidget::USkillTreeConnectionsWidget(
	const FObjectInitializer& ObjectInitializer)
	: Super(ObjectInitializer)
{
	bNeedsRedraw = true;
}

void USkillTreeConnectionsWidget::NativeConstruct()
{
	Super::NativeConstruct();

	// Bind to skill tree component events for automatic refresh
	if (SkillTreeComponent)
	{
		// Remove any existing bindings first to prevent double-binding
		SkillTreeComponent->OnSkillStateChanged.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillStateChangedHandler);
		SkillTreeComponent->OnSkillSelectionChanged.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillSelectionChangedHandler);
		SkillTreeComponent->OnSkillPurchased.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillPurchasedHandler);

		// Now bind
		SkillTreeComponent->OnSkillStateChanged.AddDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillStateChangedHandler);
		SkillTreeComponent->OnSkillSelectionChanged.AddDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillSelectionChangedHandler);
		SkillTreeComponent->OnSkillPurchased.AddDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillPurchasedHandler);
	}
}

void USkillTreeConnectionsWidget::NativeDestruct()
{
	// Unbind from events to prevent memory leaks
	if (SkillTreeComponent)
	{
		SkillTreeComponent->OnSkillStateChanged.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillStateChangedHandler);
		SkillTreeComponent->OnSkillSelectionChanged.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillSelectionChangedHandler);
		SkillTreeComponent->OnSkillPurchased.RemoveDynamic(
			this, &USkillTreeConnectionsWidget::OnSkillPurchasedHandler);
	}

	Super::NativeDestruct();
}

void USkillTreeConnectionsWidget::RefreshConnections()
{
	bNeedsRedraw = true;
	// Force widget to repaint
	if (IsValid(this))
	{
		Invalidate(EInvalidateWidgetReason::Paint);
	}
}

void USkillTreeConnectionsWidget::OnSkillStateChangedHandler(FName SkillID)
{
	RefreshConnections();
}

void USkillTreeConnectionsWidget::OnSkillSelectionChangedHandler(
	int32 TotalCost)
{
	RefreshConnections();
}

void USkillTreeConnectionsWidget::OnSkillPurchasedHandler(FName SkillID)
{
	RefreshConnections();
}

bool USkillTreeConnectionsWidget::GetSkillIDFromWidget(UUserWidget* Widget,
													   FName& OutSkillID) const
{
	if (!Widget)
		return false;

	// Try to find a property named "SkillID" on the widget
	for (TFieldIterator<FProperty> PropIt(Widget->GetClass()); PropIt; ++PropIt)
	{
		FProperty* Property = *PropIt;
		if (Property && Property->GetFName() == FName(TEXT("SkillID")))
		{
			// Check if it's a FName property
			if (FNameProperty* NameProperty =
					CastField<FNameProperty>(Property))
			{
				const void* ValuePtr =
					Property->ContainerPtrToValuePtr<void>(Widget);
				OutSkillID = NameProperty->GetPropertyValue(ValuePtr);
				return true;
			}
		}
	}

	return false;
}

void USkillTreeConnectionsWidget::FindWidgetsOfClass(
	UWidget* Root, TSubclassOf<UUserWidget> WidgetClass,
	TArray<UUserWidget*>& OutWidgets) const
{
	if (!Root || !WidgetClass)
		return;

	// Check if this widget is a UserWidget of the desired class
	if (UUserWidget* UserWidget = Cast<UUserWidget>(Root))
	{
		if (UserWidget->IsA(WidgetClass))
		{
			OutWidgets.Add(UserWidget);
		}
	}

	// If this is a panel widget, recursively search its children
	if (UPanelWidget* PanelWidget = Cast<UPanelWidget>(Root))
	{
		for (int32 i = 0; i < PanelWidget->GetChildrenCount(); ++i)
		{
			UWidget* Child = PanelWidget->GetChildAt(i);
			FindWidgetsOfClass(Child, WidgetClass, OutWidgets);
		}
	}

	// If this is a UserWidget, search its widget tree
	if (UUserWidget* UserWidget = Cast<UUserWidget>(Root))
	{
		if (UserWidget->WidgetTree)
		{
			TArray<UWidget*> AllWidgets;
			UserWidget->WidgetTree->GetAllWidgets(AllWidgets);

			for (UWidget* Widget : AllWidgets)
			{
				if (Widget != Root) // Avoid infinite recursion
				{
					FindWidgetsOfClass(Widget, WidgetClass, OutWidgets);
				}
			}
		}
	}
}

void USkillTreeConnectionsWidget::BuildNodeInfoList(
	TArray<FSkillNodeInfo>& OutNodeInfo) const
{
	OutNodeInfo.Empty();

	if (!SkillTreeComponent || !SkillNodeWidgetClass)
		return;

	// Determine root widget to search from
	UWidget* RootWidget = SkillTreeWidget;
	if (!RootWidget)
	{
		// If no parent widget is set, try to get the outer widget
		RootWidget = Cast<UWidget>(GetOuter());
		if (!RootWidget)
		{
			// As last resort, try to get root widget from widget tree
			if (WidgetTree)
			{
				RootWidget = WidgetTree->RootWidget;
			}
		}
	}

	if (!RootWidget)
	{
		UE_LOG(
			LogTemp, Error,
			TEXT(
				"SkillTreeConnectionsWidget: No valid root widget found to search for skill nodes"));
		return;
	}

	// Find all skill node widgets recursively
	TArray<UUserWidget*> SkillNodeWidgets;
	FindWidgetsOfClass(RootWidget, SkillNodeWidgetClass, SkillNodeWidgets);

	// Build info for each skill node
	for (UUserWidget* SkillNodeWidget : SkillNodeWidgets)
	{
		if (!SkillNodeWidget)
			continue;

		// Try to get the SkillID from the widget
		FName SkillID;
		if (!GetSkillIDFromWidget(SkillNodeWidget, SkillID))
			continue;

		// Get the skill node data from the component
		FSkillNodeRuntime NodeData;
		if (!SkillTreeComponent->GetSkillNodeData(SkillID, NodeData))
			continue;

		// Get the widget's geometry to determine its position
		const FGeometry& Geometry  = SkillNodeWidget->GetCachedGeometry();
		FVector2D		 LocalSize = Geometry.GetLocalSize();
		FVector2D		 AbsolutePosition = Geometry.GetAbsolutePosition();

		// Calculate center position (in absolute/screen space)
		FVector2D CenterPosition = AbsolutePosition + (LocalSize * 0.5f);

		// Build the info struct
		FSkillNodeInfo NodeInfo;
		NodeInfo.SkillID	   = SkillID;
		NodeInfo.Position	   = CenterPosition;
		NodeInfo.State		   = NodeData.CurrentState;
		NodeInfo.Prerequisites = NodeData.NodeData.Prerequisites;

		OutNodeInfo.Add(NodeInfo);
	}
}

FLinearColor
USkillTreeConnectionsWidget::GetLineColorForState(ESkillNodeState State) const
{
	switch (State)
	{
	case ESkillNodeState::Locked:
		return LockedColor;
	case ESkillNodeState::Available:
		return AvailableColor;
	case ESkillNodeState::Selected:
		return SelectedColor;
	case ESkillNodeState::Purchased:
		return PurchasedColor;
	default:
		return LockedColor;
	}
}

int32 USkillTreeConnectionsWidget::NativePaint(
	const FPaintArgs& Args, const FGeometry& AllottedGeometry,
	const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements,
	int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const
{
	int32 MaxLayerId = Super::NativePaint(Args, AllottedGeometry, MyCullingRect,
										  OutDrawElements, LayerId,
										  InWidgetStyle, bParentEnabled);

	if (!SkillTreeComponent || !SkillNodeWidgetClass)
		return MaxLayerId;

	// Build node information
	TArray<FSkillNodeInfo> NodeInfoList;
	BuildNodeInfoList(NodeInfoList);

	// Get this widget's absolute position to convert coordinates
	FVector2D ConnectionsWidgetAbsolutePosition = AllottedGeometry.GetAbsolutePosition();

	// Draw lines for each node's prerequisites
	for (const FSkillNodeInfo& DependentNode : NodeInfoList)
	{
		// Get the color for this node's connections
		FLinearColor LineColor = GetLineColorForState(DependentNode.State);

		// Draw lines to each prerequisite
		for (const FName& PrerequisiteID : DependentNode.Prerequisites)
		{
			// Find the prerequisite node in our list
			const FSkillNodeInfo* PrereqNode = NodeInfoList.FindByPredicate(
				[&PrerequisiteID](const FSkillNodeInfo& Info)
				{ return Info.SkillID == PrerequisiteID; });

			if (!PrereqNode)
				continue;

			// Convert absolute positions to local coordinates relative to this widget
			FVector2D PrereqLocalPos = PrereqNode->Position - ConnectionsWidgetAbsolutePosition;
			FVector2D DependentLocalPos = DependentNode.Position - ConnectionsWidgetAbsolutePosition;

			// Draw line from prerequisite to dependent
			TArray<FVector2D> LinePoints;
			LinePoints.Add(PrereqLocalPos);
			LinePoints.Add(DependentLocalPos);

			FSlateDrawElement::MakeLines(OutDrawElements, MaxLayerId + 1,
										 AllottedGeometry.ToPaintGeometry(),
										 LinePoints, ESlateDrawEffect::None,
										 LineColor,
										 true, // bAntialias
										 LineThickness);
		}
	}

	return MaxLayerId + 1;
}