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


#include "SMixer.h"

#include "MultiBoxBuilder.h"
#include "SMixerTrack.h"
#include "SlateOptMacros.h"
#include "SListView.h"
#include "SMixerEffectList.h"
#include "SScrollBox.h"
#include "Singleton/MixerList.h"

#define LOCTEXT_NAMESPACE "SMixer"

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION

void FMixerSelector::AddTrack(FMixerTrack* MixerTrack)
{
	if (SelectedTracks.Contains(MixerTrack))
		return;
	SelectedTracks.Add(MixerTrack);
	OnMixerTrackSelected.Broadcast(MixerTrack);
}

bool FMixerSelector::RemoveTrack(FMixerTrack* MixerTrack)
{
	if (!SelectedTracks.Contains(MixerTrack))
		return false;
	SelectedTracks.Remove(MixerTrack);
	OnMixerTrackDeselected.Broadcast(MixerTrack);
	return true;
}

void FMixerSelector::UnselectAll()
{
	for (FMixerTrack* MixerTrack : SelectedTracks)
	{
		OnMixerTrackDeselected.Broadcast(MixerTrack);
	}
	SelectedTracks.Empty();
}

SMixer::~SMixer()
{
	FMixerList& MixerList = FMixerList::Get();
	MixerList.OnMixerTrackCreated.RemoveAll(this);
	MixerList.OnMixerTrackRemoved.RemoveAll(this);
}

void SMixer::Construct(const FArguments& InArgs)
{
	FMixerList& MixerList = FMixerList::Get();

	MixerList.OnMixerTrackCreated.AddRaw(this, &SMixer::OnMixerTrackCreated);
	MixerList.OnMixerTrackRemoved.AddRaw(this, &SMixer::OnMixerTrackRemoved);

	Selector.OnMixerTrackSelected.AddRaw(this, &SMixer::OnMixerTrackSelected);
	Selector.OnMixerTrackDeselected.AddRaw(this, &SMixer::OnMixerTrackDeselected);
	
	ChildSlot
	[
		SNew(SHorizontalBox)
		+SHorizontalBox::Slot()
		.FillWidth(1.f)
		[
			SAssignNew(ListView, SScrollBox)
			.AnimateWheelScrolling(true)
			.Orientation(EOrientation::Orient_Horizontal)
			.ScrollBarThickness(FVector2D(2))
		]
		+SHorizontalBox::Slot()
		.AutoWidth()
		[
			SNew(SBox)
			.WidthOverride(200)
			[
				SAssignNew(EffectList, SMixerEffectList)
			]
		]
	];

	for (FMixerTrack* Mixer : MixerList)
	{
		OnMixerTrackCreated(Mixer);
	}
}

FReply SMixer::OnMouseButtonUp(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
{
	if (MouseEvent.GetEffectingButton() == EKeys::RightMouseButton)
	{
		FMenuBuilder MenuBuilder(true, nullptr);
		MenuBuilder.AddMenuEntry(
			LOCTEXT("AddDummyMixerTrack", "创建傀儡轨道"),
			LOCTEXT("AddDummyMixerTrack_Tooltip", "创建一个新的傀儡轨道"),
			FSlateIcon(),
			FUIAction(FExecuteAction::CreateLambda([this]()
			{
				FMixerList& MixerList = FMixerList::Get();
				MixerList.CreateDummyTrack("Dummy");
			}))
		);
		
		FSlateApplication::Get().PushMenu(SharedThis(this), FWidgetPath(), MenuBuilder.MakeWidget(), FSlateApplication::Get().GetCursorPos(), FPopupTransitionEffect::ContextMenu);
	}
	else if (MouseEvent.GetEffectingButton() == EKeys::LeftMouseButton)
	{
		Selector.UnselectAll();
		EffectList->SetMixerTrack(nullptr);
	}
	return FReply::Unhandled();
}

FReply SMixer::OnKeyDown(const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent)
{
	if (InKeyEvent.GetKey() == EKeys::LeftShift || InKeyEvent.GetKey() == EKeys::RightShift)
	{
		bShiftDown = true;
	}
	
	if (InKeyEvent.GetKey() == EKeys::Delete)
	{
		for (FMixerTrack* MixerTrack : Selector.GetSelectedTracks())
		{
			FMixerList::Get().RemoveTrack(MixerTrack);
		}
		Selector.UnselectAll();
	}
	return FReply::Unhandled();
}

FReply SMixer::OnKeyUp(const FGeometry& MyGeometry, const FKeyEvent& InKeyEvent)
{
	if (InKeyEvent.GetKey() == EKeys::LeftShift || InKeyEvent.GetKey() == EKeys::RightShift)
	{
		bShiftDown = false;
	}
	return FReply::Unhandled();
}

void SMixer::OnMixerTrackCreated(FMixerTrack* MixerTrack)
{
	ListView->AddSlot()
	[
		SNew(SMixerTrack)
		.MixerTrack(MixerTrack)
		.OnClicked(this, &SMixer::OnMixerTrackClicked)
	];
}

void SMixer::OnMixerTrackRemoved(FMixerTrack* MixerTrack)
{
	if (Selector.RemoveTrack(MixerTrack))
	{
		Selector.AddTrack(FMixerList::Get().GetMaster());
	}
	
	ForeachMixerTrackWidget([&, this](TSharedRef<SMixerTrack> MixerTrackWidget)
	{
		if (MixerTrackWidget->GetMixerTrack() == MixerTrack)
		{
			ListView->RemoveSlot(MixerTrackWidget);
			return false;
		}
		return true;
	});
	
}

void SMixer::OnMixerTrackClicked(FMixerTrack* InMixerTrack)
{
	Selector.UnselectAll();

	if (bShiftDown)
	{
		const TArray<FMixerTrack*>& Selected = Selector.GetSelectedTracks();
		if (Selected.Num() > 0)
		{
			const TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
			FChildren* Children = ScrollPanel->GetChildren();
			for (int32 i = 0; i < Children->Num(); i++)
			{
				TSharedRef<SWidget> Child = Children->GetChildAt(i);
				const TSharedRef<SMixerTrack> MixerTrackWidget = StaticCastSharedRef<SMixerTrack>(Child);
				if (MixerTrackWidget->GetMixerTrack() == Selected[0])
				{
					int32 StartIndex = i;
					for (int32 j = 0; j < Children->Num(); j++)
					{
						TSharedRef<SWidget> Child2 = Children->GetChildAt(j);
						const TSharedRef<SMixerTrack> MixerTrackWidget2 = StaticCastSharedRef<SMixerTrack>(Child2);
						if (MixerTrackWidget2->GetMixerTrack() == InMixerTrack)
						{
							int32 EndIndex = j;
							if (StartIndex > EndIndex)
							{
								const int32 Temp = StartIndex;
								StartIndex = EndIndex;
								EndIndex = Temp;
							}
							for (int32 k = StartIndex; k <= EndIndex; k++)
							{
								TSharedRef<SWidget> Child3 = Children->GetChildAt(k);
								const TSharedRef<SMixerTrack> MixerTrackWidget3 = StaticCastSharedRef<SMixerTrack>(Child3);
								Selector.AddTrack(MixerTrackWidget3->GetMixerTrack());
							}
							break;
						}
					}
					break;
				}
			}
		}
	}
	else
	{
		Selector.AddTrack(InMixerTrack);
		EffectList->SetMixerTrack(InMixerTrack);
	}
}

void SMixer::OnMixerTrackSelected(FMixerTrack* InMixerTrack)
{
	ForeachMixerTrackWidget([&, this](TSharedRef<SMixerTrack> MixerTrackWidget)
	{
		if (MixerTrackWidget->GetMixerTrack() == InMixerTrack)
		{
			MixerTrackWidget->SetSelected(true);
			return false;
		}
		return true;
	});
}

void SMixer::OnMixerTrackDeselected(FMixerTrack* InMixerTrack)
{
	ForeachMixerTrackWidget([&, this](TSharedRef<SMixerTrack> MixerTrackWidget)
	{
		if (MixerTrackWidget->GetMixerTrack() == InMixerTrack)
		{
			MixerTrackWidget->SetSelected(false);
			return false;
		}
		return true;
	});
}

void SMixer::ForeachMixerTrackWidget(TFunction<bool(TSharedRef<SMixerTrack>)> InFunction)
{
	const TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
	FChildren* Children = ScrollPanel->GetChildren();
	for (int32 i = 0; i < Children->Num(); i++)
	{
		TSharedRef<SWidget> Child = Children->GetChildAt(i);
		const TSharedRef<SMixerTrack> MixerTrackWidget = StaticCastSharedRef<SMixerTrack>(Child);
		if (!InFunction(MixerTrackWidget))
			break;
	}
}


END_SLATE_FUNCTION_BUILD_OPTIMIZATION
#undef LOCTEXT_NAMESPACE