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


#include "ChannelRackMidiThumbnail.h"

#include "SImage.h"
#include "SInvalidationPanel.h"
#include "SlateApplication.h"
#include "SlateOptMacros.h"
#include "SScrollBox.h"
#include "SViewport.h"
#include "Midi/MidiMessageSequence.h"
#include "Singleton/MidiSequencer.h"
#include "UI/Widget/MainWindow.h"
#include "UI/Widget/SUpdatableImage.h"
#include "UI/Widget/Thumbnail.h"
#include "UI/Widget/WindowManager.h"
#include "UI/Widget/PianoRoll/SPianoRoll.h"

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION

SChannelRackMidiThumbnail::~SChannelRackMidiThumbnail()
{
	SetPattern(nullptr);
}

void SChannelRackMidiThumbnail::SetPattern(FMidiPattern* InPattern)
{
	if (CurrentPattern)
	{
		CurrentPattern->OnChanged.RemoveAll(this);
		CurrentPattern->OnPlay.RemoveAll(this);
	}
	if (!InPattern)
		return;
	CurrentPattern = InPattern;
	CurrentPattern->OnChanged_MainThread.AddRaw(this, &SChannelRackMidiThumbnail::OnChanged);
	CurrentPattern->OnPlay.AddRaw(this, &SChannelRackMidiThumbnail::OnPatternPlay);
	OnChanged(PluginHost, &InPattern->GetSequence(PluginHost));
}

void SChannelRackMidiThumbnail::Construct(const FArguments& InArgs, FPluginHost* InPluginHost)
{
	PluginHost = InPluginHost;
	SetPattern(InArgs._Pattern);
	
	ChildSlot
	[
		SNew(SInvalidationPanel)
		[
			SAssignNew(UpdatableImage, SUpdatableImage)
			.OnPostResize(this, &SChannelRackMidiThumbnail::UpdateMidiThumbnail)
			.UpdateInterval(0)
		]
	];
	
	if (InArgs._Pattern)
		OnChanged(PluginHost, &InArgs._Pattern->GetSequence(InPluginHost));
}

FReply SChannelRackMidiThumbnail::OnMouseButtonDown(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
{
	if (!CurrentPattern)
		return FReply::Unhandled();
	FMidiMessageSequence* MidiSequence = &CurrentPattern->GetSequence(PluginHost);
	TSharedPtr<SPianoRoll> PianoRoll = SNew(SPianoRoll, MidiSequence, PluginHost);

	
	FWindowManager::Get().GetMainWindow()->CreateChildWindow(
		FVector2D(100, 100),
		TEXT(""),
		PianoRoll.ToSharedRef()
		);
	PianoRoll->InitScrollBar();
	return FReply::Unhandled();
}

int32 SChannelRackMidiThumbnail::OnPaint(const FPaintArgs& Args, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const
{
	LayerId = SCompoundWidget::OnPaint(Args, AllottedGeometry, MyCullingRect, OutDrawElements, LayerId, InWidgetStyle, bParentEnabled);
	if (CurrentPattern)
	{
		const double EndTime = CurrentPattern->GetLength();
		const double CurrentPercent = LastPatternPos / EndTime * (double)AllottedGeometry.Size.X;
		TArray<FVector2f> Points;
		Points.Add(FVector2f(CurrentPercent, 0));
		Points.Add(FVector2f(CurrentPercent, AllottedGeometry.Size.Y));
		FSlateDrawElement::MakeLines(
			OutDrawElements,
			++LayerId,
			AllottedGeometry.ToPaintGeometry(),
			Points,
			ESlateDrawEffect::None,
			FLinearColor::Red,
			true,
			1.f
		);
	}
	return LayerId;
}

void SChannelRackMidiThumbnail::OnChanged(FPluginHost* Host, FMidiMessageSequence* Changed)
{
	if (Host != PluginHost)
		return;
	UpdatableImage->NeedRedraw();
}

void SChannelRackMidiThumbnail::OnPatternPlay(FPatternInstance* PatternInstance, AudioFrame PatternTick, uint32 Length)
{
	LastPatternPos = PatternTick;
}

void SChannelRackMidiThumbnail::UpdateMidiThumbnail(FImageData& ImageData)
{
	if (!CurrentPattern)
		return;
	const FMidiMessageSequence* MidiSequence = &CurrentPattern->GetSequence(PluginHost);

	ImageData.ClearColor(FColor::Black);
	Thumbnail::GenerateMidiThumbnail(MidiSequence, ImageData);
}

END_SLATE_FUNCTION_BUILD_OPTIMIZATION