// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.

#include "LogVisualizerPCH.h"
#include "SLogBar.h"

const float SLogBar::SubPixelMinSize = 3.0f;
const float SLogBar::TimeUnit = 1.f/60.f;
const float SLogBar::MaxUnitSizePx = 16.f;

FColor SLogBar::ColorPalette[] = {
	FColor( 0xff00A480 ),
	FColor( 0xff62E200 ),
	FColor( 0xff8F04A8 ),
	FColor( 0xff1F7B67 ),
	FColor( 0xff62AA2A ),
	FColor( 0xff70227E ),
	FColor( 0xff006B53 ),
	FColor( 0xff409300 ),
	FColor( 0xff5D016D ),
	FColor( 0xff34D2AF ),
	FColor( 0xff8BF13C ),
	FColor( 0xffBC38D3 ),
	FColor( 0xff5ED2B8 ),
	FColor( 0xffA6F16C ),
	FColor( 0xffC262D3 ),
	FColor( 0xff0F4FA8 ),
	FColor( 0xff00AE68 ),
	FColor( 0xffDC0055 ),
	FColor( 0xff284C7E ),
	FColor( 0xff21825B ),
	FColor( 0xffA52959 ),
	FColor( 0xff05316D ),
	FColor( 0xff007143 ),
	FColor( 0xff8F0037 ),
	FColor( 0xff4380D3 ),
	FColor( 0xff36D695 ),
	FColor( 0xffEE3B80 ),
	FColor( 0xff6996D3 ),
	FColor( 0xff60D6A7 ),
	FColor( 0xffEE6B9E )
};

void SLogBar::Construct( const FArguments& InArgs )
{
	OnSelectionChanged = InArgs._OnSelectionChanged;
	OnGeometryChanged = InArgs._OnGeometryChanged;
	ShouldDrawSelection = InArgs._ShouldDrawSelection;
	DisplayedTime = InArgs._DisplayedTime;
	CurrentEntryIndex = InArgs._CurrentEntryIndex;

	BackgroundImage = FEditorStyle::GetBrush("LogVisualizer.LogBar.Background");
	FillImage = FEditorStyle::GetBrush("LogVisualizer.LogBar.EntryDefault");
	SelectedImage = FEditorStyle::GetBrush("LogVisualizer.LogBar.Selected");
	TimeMarkImage = FEditorStyle::GetBrush("LogVisualizer.LogBar.TimeMark");
	
	LastHoveredEvent = INDEX_NONE;
	Zoom = 1.0f;
	Offset = 0.0f;
	StartTime = 0.0;
	TotalTime = 1.0;
	RowIndex = INDEX_NONE;
	bShouldDrawSelection = false;
}

int32 SLogBar::OnPaint( const FGeometry& AllottedGeometry, const FSlateRect& MyClippingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled ) const
{
	// Used to track the layer ID we will return.
	int32 RetLayerId = LayerId;

	bool bEnabled = ShouldBeEnabled( bParentEnabled );
	const ESlateDrawEffect::Type DrawEffects = bEnabled ? ESlateDrawEffect::None : ESlateDrawEffect::DisabledEffect;
		
	const FColor ColorAndOpacitySRGB = InWidgetStyle.GetColorAndOpacityTint();
	static const FColor SelectedBarColor(255, 255, 255, 255);
	static const FColor CurrentTimeColor(140, 255, 255, 255);

	// Paint inside the border only. 
	const FVector2D BorderPadding = FEditorStyle::GetVector("ProgressBar.BorderPadding");
	FPaintGeometry ForegroundPaintGeometry = AllottedGeometry.ToInflatedPaintGeometry( -BorderPadding );
	const FSlateRect ForegroundClippingRect = ForegroundPaintGeometry.ToSlateRect().IntersectionWith( MyClippingRect );

	FSlateDrawElement::MakeBox(
		OutDrawElements,
		RetLayerId++,
		AllottedGeometry.ToPaintGeometry(),
		BackgroundImage,
		MyClippingRect,
		DrawEffects,
		ColorAndOpacitySRGB
	);	
	
	// Draw all bars
	for (int32 EntryIndex = 0; EntryIndex < Entries.Num(); ++EntryIndex)
	{
		TSharedPtr<FVisLogEntry> Entry = Entries[EntryIndex];
		float StartX, EndX;
		if (CalculateEntryGeometry( Entry.Get(), AllottedGeometry, StartX, EndX ) )
		{
			// Draw Event bar
			FSlateDrawElement::MakeBox(
				OutDrawElements,
				RetLayerId++,
				AllottedGeometry.ToPaintGeometry(
					FVector2D( StartX, 0.0f ),
					FVector2D( EndX - StartX, AllottedGeometry.Size.Y )),
				FillImage,
				ForegroundClippingRect,
				DrawEffects,
				ColorPalette[0]
				);
		}
	}

	// draw "current time"
	{
		const float RelativePos = Offset + (DisplayedTime.Execute() - StartTime) / TotalTime * Zoom;
		const float PosX = (float)(AllottedGeometry.Size.X * RelativePos);
		const float ClampedSize = FMath::Clamp(TimeUnit / TotalTime * Zoom, 0.0f, 1.0f );
		float CurrentTimeMarkWidth = (float)FMath::Max(AllottedGeometry.Size.X * ClampedSize
			, ClampedSize > 0.0f ? SubPixelMinSize : 0.0f);
		
		// Draw Event bar
		FSlateDrawElement::MakeBox(
			OutDrawElements,
			RetLayerId++,
			AllottedGeometry.ToPaintGeometry(
			FVector2D( PosX - 2.f, 0.0f ),
			FVector2D( CurrentTimeMarkWidth + 4.f, AllottedGeometry.Size.Y )),
			TimeMarkImage,
			ForegroundClippingRect,
			DrawEffects,
			CurrentTimeColor
			);
	}
	
	if (bShouldDrawSelection)
	{
		int32 EntryIndex = CurrentEntryIndex.IsBound() ? CurrentEntryIndex.Execute() : INDEX_NONE;
		if (Entries.IsValidIndex(EntryIndex) == true)
		{
			TSharedPtr<FVisLogEntry> Entry = Entries[EntryIndex];
			float StartX, EndX;
			if (CalculateEntryGeometry( Entry.Get(), AllottedGeometry, StartX, EndX ) )
			{
				// Draw Event bar
				FSlateDrawElement::MakeBox(
					OutDrawElements,
					RetLayerId++,
					AllottedGeometry.ToPaintGeometry(
					FVector2D( StartX, 0.0f ),
					FVector2D( EndX - StartX, AllottedGeometry.Size.Y )),
					SelectedImage,
					ForegroundClippingRect,
					DrawEffects,
					SelectedBarColor
				);
			}
		}
	}

	return RetLayerId - 1;
}

void SLogBar::Tick( const FGeometry& AllottedGeometry, const double InCurrentTime, const float InDeltaTime )
{
	if( OnGeometryChanged.IsBound() )
	{
		if( AllottedGeometry != this->LastGeometry )
		{
			OnGeometryChanged.ExecuteIfBound( AllottedGeometry );
			LastGeometry = AllottedGeometry;
		}
	}

	bShouldDrawSelection = ShouldDrawSelection.IsBound() && ShouldDrawSelection.Execute() == true;

	SLeafWidget::Tick( AllottedGeometry, InCurrentTime, InDeltaTime );
}

void SLogBar::SelectEntry(const FGeometry& MyGeometry, const float ClickX)
{	
	int32 BestDistance = 0x7fffffff;
	int32 LastDistance = 0x7fffffff;

	// Go through all events and check if at least one has been clicked
	int32 BestIndex = INDEX_NONE;
	int32 EntryIndex = INDEX_NONE;
	for( EntryIndex = 0; EntryIndex < Entries.Num(); ++EntryIndex )
	{
		TSharedPtr<FVisLogEntry> Entry = Entries[EntryIndex];
		float StartX, EndX;
		if( CalculateEntryGeometry( Entry.Get(), MyGeometry, StartX, EndX ) )
		{
			const int32 Distance = FMath::Abs(ClickX - StartX);
			if (Distance < BestDistance)
			{
				BestDistance = Distance;
				BestIndex = EntryIndex;
			}
			else if (Distance > LastDistance)
			{
				break;
			}
			LastDistance = Distance;
		}
	}

	SelectEntryAtIndex(BestIndex);
}

int32 SLogBar::GetEntryIndexAtTime(float Time) const
{
	int BestIndex = INDEX_NONE;
	float BestTimeDiff = MAX_FLT;
	float LastTimeDiff = MAX_FLT;

	// Go through all events and check if at least one has been clicked
	int32 EntryIndex = INDEX_NONE;
	for( EntryIndex = 0; EntryIndex < Entries.Num(); ++EntryIndex )
	{
		TSharedPtr<FVisLogEntry> Entry = Entries[EntryIndex];
		const float TimeDiff = FMath::Abs(Entry->TimeStamp - Time);

		if (TimeDiff < BestTimeDiff)
		{
			BestTimeDiff = TimeDiff;
			BestIndex = EntryIndex;
		}
		else if (TimeDiff > LastTimeDiff)
		{
			break;
		}
		LastTimeDiff = TimeDiff;
	}

	return BestIndex;
}

void SLogBar::SelectEntryAtIndex(const int32 Index)
{
	if (Entries.IsValidIndex(Index) == false)
	{
		return;
	}

	// Execute OnSelectionChanged delegate
	if( OnSelectionChanged.IsBound() )
	{
		OnSelectionChanged.ExecuteIfBound(Entries[Index]);
	}
}

FReply SLogBar::OnMouseButtonDown( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent )
{
	if (MouseEvent.GetEffectingButton() == EKeys::LeftMouseButton)
	{
		// Translate click position from absolute to graph space
		const float ClickX = MyGeometry.AbsoluteToLocal( MouseEvent.GetScreenSpacePosition() ).X;//( MyGeometry.AbsoluteToLocal( MouseEvent.GetScreenSpacePosition() ).X / MyGeometry.Size.X ) / Zoom - Offset / Zoom;
		SelectEntry(MyGeometry, ClickX);

		return FReply::Handled();
	}
	else
	{
		return FReply::Unhandled();
	}
}

FReply SLogBar::OnMouseButtonUp( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent )
{
	// same behavior as when OnMouseButtonDown
	return OnMouseButtonDown(MyGeometry, MouseEvent);
}


/**
 * The system calls this method to notify the widget that a mouse moved within it. This event is bubbled.
 *
 * @param MyGeometry The Geometry of the widget receiving the event
 * @param MouseEvent Information about the input event
 *
 * @return Whether the event was handled along with possible requests for the system to take action.
 */
FReply SLogBar::OnMouseMove( const FGeometry& MyGeometry, const FPointerEvent& MouseEvent )
{
	const float HoverX = ( MyGeometry.AbsoluteToLocal( MouseEvent.GetScreenSpacePosition() ).X / MyGeometry.Size.X ) / Zoom - Offset / Zoom;

	int32 HoveredEventIndex = INDEX_NONE;

	for( int32 EntryIndex = 0; EntryIndex < Entries.Num(); EntryIndex++ )
	{
		TSharedPtr<FVisLogEntry> Entry = Entries[EntryIndex];

		if( HoverX >= Entry->TimeStamp && Entry->TimeStamp <= HoverX + 1)
		{
			HoveredEventIndex = EntryIndex;
			break;
		}
	}

	if( HoveredEventIndex != LastHoveredEvent )
	{
		/*if( HoveredEventIndex != INDEX_NONE )
		{
			this->SetToolTipText( Entries[ HoveredEventIndex ]->EventName );
		}
		else
		{
			this->SetToolTipText( TEXT( "" ) );
		}*/
		LastHoveredEvent = HoveredEventIndex;
	}

	if (MouseEvent.IsMouseButtonDown(EKeys::LeftMouseButton))
	{
		SelectEntry(MyGeometry, MyGeometry.AbsoluteToLocal( MouseEvent.GetScreenSpacePosition() ).X);
	}

	return SLeafWidget::OnMouseMove( MyGeometry, MouseEvent );
}

FVector2D SLogBar::ComputeDesiredSize() const
{
	return FVector2D( 500.0f, 24.0f );
}

void SLogBar::SetEntries(const TArray<TSharedPtr<FVisLogEntry> >& InEntries, float InStartTime, float InTotalTime)
{
	Entries = InEntries;
	StartTime = InStartTime;
	TotalTime = InTotalTime;
}

void SLogBar::OnCurrentTimeChanged(float NewTime)
{
	const bool bUpdateSelection = ShouldDrawSelection.IsBound() 
		&& ShouldDrawSelection.Execute() == true ;

	if (bUpdateSelection)
	{
		// find entry closest to desired time
		FSimpleDelegateGraphTask::CreateAndDispatchWhenReady(
			FSimpleDelegateGraphTask::FDelegate::CreateSP(this, &SLogBar::SelectEntryAtIndex, GetEntryIndexAtTime(NewTime))
			, TEXT("Updating Log Entry shown in LogVisualizer")
			, NULL
			, ENamedThreads::GameThread
			);
	}
}

void SLogBar::SetZoomAndOffset(float InZoom, float InOffset)
{
	SetZoom(InZoom);
	SetOffset(InOffset);
} 

void SLogBar::UpdateShouldDrawSelection()
{
	/*const bool bNewShouldDraw = ShouldDrawSelection.Execute();
	if (bNewShouldDraw != !!bShouldDrawSelection)
	{
	bShouldDrawSelection = bNewShouldDraw;
	if (bNewShouldDraw)
	{
	check(DisplayedTime.IsBound());
	SelectEntryAtIndex(GetEntryIndexAtTime(DisplayedTime.Execute()));
	}
	}*/
}