// Fill out your copyright notice in the Description page of Project Settings.


#include "SPatternInstance.h"

#include "SButton.h"
#include "SInvalidationPanel.h"
#include "SlateOptMacros.h"
#include "STextBlock.h"
#include "SViewport.h"
#include "Pattern/PatternInstance.h"
#include "Render/UpdatableTexture.h"
#include "UI/Widget/SUpdatableTexture.h"
#include "Widgets/SBoxPanel.h"

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION

void SPatternInstance::Construct(const FArguments& InArgs)
{
	PatternInstance = InArgs._PatternInstance;
	FrameToPixel = InArgs._FrameToPixel;
	SnapFrame = InArgs._SnapFrame;
	FrameViewRange = InArgs._FrameViewRange;
	
	ChildSlot
	[
		SNew(SOverlay)
		+SOverlay::Slot()
		[
			SNew(SBorder)
			.BorderBackgroundColor(FLinearColor(0, 0, 0, 0.3f))
		]

		+SOverlay::Slot()
		[
			SNew(SVerticalBox)
			+SVerticalBox::Slot()
			.AutoHeight()
			[
				SNew(SHorizontalBox)
				+SHorizontalBox::Slot()
				.AutoWidth()
				[
					SNew(SButton)
					.Text(FText::FromString("X"))
					.OnClicked(this, &SPatternInstance::OpenPatternMenu)
				]
				+SHorizontalBox::Slot()
				.FillWidth(1.f)
				.VAlign(VAlign_Center)
				[
					SNew(STextBlock)
					.Text(FText::FromString(PatternInstance->GetOwner()->Name))
					.OverflowPolicy(ETextOverflowPolicy::Ellipsis)
					.Justification(ETextJustify::Left)
				]
			]
			+SVerticalBox::Slot()
			.FillHeight(1.f)
			[
				GetViewWidget()
			]
		]
	];
}

FReply SPatternInstance::OnMouseButtonDown(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
{
	if (ResizeDirection != ResizeDir::None)
	{
		FPatternSelector::Get().SelectPatternInstance(PatternInstance);
		const TRange<AudioFrame>& Range = PatternInstance->TimeRange;
		BeginPatternStart = Range.GetLowerBoundValue();
		BeginPatternEnd = Range.GetUpperBoundValue();
		MouseDownPos = MouseEvent.GetScreenSpacePosition();
		BeginPatternPos = PatternInstance->Pos;
		return FReply::Handled().CaptureMouse(AsShared());
	}
	return FReply::Unhandled();
}

FReply SPatternInstance::OnMouseButtonUp(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
{
	if (ResizeDirection != ResizeDir::None)
	{
		PatternInstance->RequestEndSetting();
		return FReply::Handled().ReleaseMouseCapture();
	}
	return FReply::Unhandled();
}

FReply SPatternInstance::OnMouseMove(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
{
	const FVector2f LocalMousePos = MyGeometry.AbsoluteToLocal(MouseEvent.GetScreenSpacePosition());
	
	if (MouseEvent.IsMouseButtonDown(EKeys::LeftMouseButton))
	{
		const float MouseDelta = (MouseEvent.GetScreenSpacePosition().X - MouseDownPos.X) / MyGeometry.Scale;
		const float Scaler = FrameToPixel.Get();
		const bool NoSnap = MouseEvent.GetModifierKeys().IsAltDown();
		double Delta = MouseDelta / Scaler;
		if (!NoSnap)
			Delta = FMath::GridSnap(Delta, SnapFrame.Get());

		switch (ResizeDirection)
		{
			case ResizeDir::None: break;
			case ResizeDir::Left:
			{
				AudioFrame NewRangeStart = BeginPatternStart + Delta;
				AudioFrame NewPos =  BeginPatternPos + Delta;
				if (NewRangeStart.Pos < 0)
				{
					NewPos -= NewRangeStart;
					NewRangeStart = 0;
				}
				if (NewPos.Pos < 0)
				{
					NewRangeStart -= NewPos;
					NewPos = 0;
				}
				PatternInstance->TimeRange.SetLowerBoundValue(NewRangeStart);
				PatternInstance->SetMidiPos(NewPos.Ticks());
				return FReply::Handled();
			}
			case ResizeDir::Right:
			{
				const AudioFrame NewRangeEnd = FMath::Max<AudioFrame>(0, BeginPatternEnd + Delta);
				PatternInstance->TimeRange.SetUpperBoundValue(NewRangeEnd);
				return FReply::Handled();
			}
			default: ;
		}
	}
	else
	{
		if (LocalMousePos.X <= ResizeHandleSize)
		{
			ResizeDirection = ResizeDir::Left;
		}
		else if (LocalMousePos.X >= MyGeometry.GetLocalSize().X - ResizeHandleSize)
		{
			ResizeDirection = ResizeDir::Right;
		}
		else
		{
			ResizeDirection = ResizeDir::None;
		}
		switch (ResizeDirection)
		{
			case ResizeDir::None: SetCursor(EMouseCursor::Default); break;
			case ResizeDir::Left:
			case ResizeDir::Right: SetCursor(EMouseCursor::ResizeLeftRight);  break;
			default: ;
		}
	}
	
	return FReply::Unhandled();
}

END_SLATE_FUNCTION_BUILD_OPTIMIZATION