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

#include "SequencerPrivatePCH.h"
#include "Toolkits/IToolkitHost.h"
#include "SequencerAssetEditor.h"
#include "Editor/LevelEditor/Public/LevelEditor.h"

#define LOCTEXT_NAMESPACE "Sequencer"

const FName FSequencerAssetEditor::SequencerMainTabId( TEXT( "Sequencer_SequencerMain" ) );

namespace SequencerDefs
{
	static const FName SequencerAppIdentifier( TEXT( "SequencerApp" ) );
}
void FSequencerAssetEditor::RegisterTabSpawners(const TSharedRef<class FTabManager>& TabManager)
{
	const IWorkspaceMenuStructure& MenuStructure = WorkspaceMenu::GetMenuStructure();

	if( IsSequencerEnabled() && !IsWorldCentricAssetEditor() )
	{
		TabManager->RegisterTabSpawner( SequencerMainTabId, FOnSpawnTab::CreateSP(this, &FSequencerAssetEditor::SpawnTab_SequencerMain) )
			.SetDisplayName( LOCTEXT("SequencerMainTab", "Sequencer") )
			.SetGroup( MenuStructure.GetAssetEditorCategory() );
	}

}

void FSequencerAssetEditor::UnregisterTabSpawners(const TSharedRef<class FTabManager>& TabManager)
{
	if( IsSequencerEnabled() && !IsWorldCentricAssetEditor() )
	{
		TabManager->UnregisterTabSpawner( SequencerMainTabId );
	}
	
	// @todo remove when world-centric mode is added
	FLevelEditorModule& LevelEditorModule = FModuleManager::LoadModuleChecked<FLevelEditorModule>("LevelEditor");
	LevelEditorModule.AttachSequencer( SNullWidget::NullWidget, nullptr );
}

void FSequencerAssetEditor::InitSequencerAssetEditor( const EToolkitMode::Type Mode, const TSharedPtr< class IToolkitHost >& InitToolkitHost, UMovieScene* InRootMovieScene, const TArray<FOnCreateTrackEditor>& TrackEditorDelegates, bool bEditWithinLevelEditor )
{
	if(InitToolkitHost.IsValid())
	{
		const TSharedRef<FTabManager::FLayout> StandaloneDefaultLayout = FTabManager::NewLayout("Standalone_Sequencer_Layout")
		->AddArea
		(
			FTabManager::NewPrimaryArea()
			->Split
			(
				FTabManager::NewStack()
				->AddTab(SequencerMainTabId, ETabState::OpenedTab)
			)
		);

		const bool bCreateDefaultStandaloneMenu = true;
		const bool bCreateDefaultToolbar = false;
		FAssetEditorToolkit::InitAssetEditor(Mode, InitToolkitHost, SequencerDefs::SequencerAppIdentifier, StandaloneDefaultLayout, bCreateDefaultStandaloneMenu, bCreateDefaultToolbar, InRootMovieScene);
	}

	// Init Sequencer 
	Sequencer = MakeShareable(new FSequencer);
	Sequencer->InitSequencer( InRootMovieScene, InitToolkitHost, TrackEditorDelegates, bEditWithinLevelEditor);

	if(bEditWithinLevelEditor)
	{
		// @todo remove when world-centric mode is added
		FLevelEditorModule& LevelEditorModule = FModuleManager::LoadModuleChecked<FLevelEditorModule>("LevelEditor");

		LevelEditorModule.AttachSequencer( Sequencer->GetSequencerWidget(), SharedThis(this));
			
		// We need to find out when the user loads a new map, because we might need to re-create puppet actors
		// when previewing a MovieScene
		LevelEditorModule.OnMapChanged().AddSP(Sequencer.ToSharedRef(), &FSequencer::OnMapChanged);

		AttachTransportControlsToViewports();
	}
}


FSequencerAssetEditor::FSequencerAssetEditor()
{

}

FSequencerAssetEditor::~FSequencerAssetEditor()
{
	DetachTransportControlsFromViewports();


	// Unregister delegates
	if( FModuleManager::Get().IsModuleLoaded( TEXT( "LevelEditor" ) ) )
	{
		auto& LevelEditorModule = FModuleManager::LoadModuleChecked< FLevelEditorModule >( TEXT( "LevelEditor" ) );
		LevelEditorModule.OnMapChanged().RemoveAll( this );
	}
}


TSharedRef<SDockTab> FSequencerAssetEditor::SpawnTab_SequencerMain(const FSpawnTabArgs& Args)
{
	check(Args.GetTabId() == SequencerMainTabId);

	return SNew(SDockTab)
		.Icon( FEditorStyle::GetBrush("Sequencer.Tabs.SequencerMain") )
		.Label( LOCTEXT("SequencerMainTitle", "Sequencer") )
		.TabColorScale( GetTabColorScale() )
		[
			Sequencer->GetSequencerWidget()
		];
}


FName FSequencerAssetEditor::GetToolkitFName() const
{
	static FName SequencerName("Sequencer");
	return SequencerName;
}

FText FSequencerAssetEditor::GetBaseToolkitName() const
{
	return LOCTEXT("AppLabel", "Sequencer");
}


FLinearColor FSequencerAssetEditor::GetWorldCentricTabColorScale() const
{
	return FLinearColor( 0.7, 0.0f, 0.0f, 0.5f );
}


FString FSequencerAssetEditor::GetWorldCentricTabPrefix() const
{
	return LOCTEXT("WorldCentricTabPrefix", "Sequencer ").ToString();
}


void FSequencerAssetEditor::AttachTransportControlsToViewports()
{
	FLevelEditorModule* Module = FModuleManager::Get().LoadModulePtr<FLevelEditorModule>("LevelEditor");
	if (Module)
	{
		TSharedPtr<ILevelEditor> LevelEditor = Module->GetFirstLevelEditor();
		const TArray< TSharedPtr<ILevelViewport> >& LevelViewports = LevelEditor->GetViewports();
		
		FEditorWidgetsModule& EditorWidgetsModule = FModuleManager::Get().LoadModuleChecked<FEditorWidgetsModule>( "EditorWidgets" );

		TSharedRef<FSequencer> SequencerRef = Sequencer.ToSharedRef();

		FTransportControlArgs TransportControlArgs;
		TransportControlArgs.OnForwardPlay.BindSP(SequencerRef, &FSequencer::OnPlay);
		TransportControlArgs.OnRecord.BindSP(SequencerRef, &FSequencer::OnRecord);
		TransportControlArgs.OnForwardStep.BindSP(SequencerRef, &FSequencer::OnStepForward);
		TransportControlArgs.OnBackwardStep.BindSP(SequencerRef, &FSequencer::OnStepBackward);
		TransportControlArgs.OnForwardEnd.BindSP(SequencerRef, &FSequencer::OnStepToEnd);
		TransportControlArgs.OnBackwardEnd.BindSP(SequencerRef, &FSequencer::OnStepToBeginning);
		TransportControlArgs.OnToggleLooping.BindSP(SequencerRef, &FSequencer::OnToggleLooping);
		TransportControlArgs.OnGetLooping.BindSP(SequencerRef, &FSequencer::IsLooping);
		TransportControlArgs.OnGetPlaybackMode.BindSP(SequencerRef, &FSequencer::GetPlaybackMode);

		for ( const TSharedPtr<ILevelViewport>& LevelViewport : LevelViewports )
		{
			TWeakPtr<ILevelViewport> LevelViewportWeakPtr = LevelViewport;
			
			TSharedPtr<SWidget> TransportControl =
				SNew(SHorizontalBox)
				.Visibility(EVisibility::SelfHitTestInvisible)
				+SHorizontalBox::Slot()
				.FillWidth(1)
				.HAlign(HAlign_Center)
				.VAlign(VAlign_Bottom)
				.Padding(4.f)
				[
					SNew(SBorder)
					.Padding(4.f)
					.Cursor( EMouseCursor::Default )
					.BorderImage( FEditorStyle::GetBrush( "FilledBorder" ) )
					.Visibility(this, &FSequencerAssetEditor::GetTransportControlVisibility, LevelViewportWeakPtr)
					.Content()
					[
						EditorWidgetsModule.CreateTransportControl(TransportControlArgs)
					]
				];

			LevelViewport->AddOverlayWidget(TransportControl.ToSharedRef());

			TransportControls.Add(LevelViewportWeakPtr, TransportControl);
		}
	}
}


void FSequencerAssetEditor::DetachTransportControlsFromViewports()
{
	FLevelEditorModule* Module = FModuleManager::Get().LoadModulePtr<FLevelEditorModule>("LevelEditor");
	if (Module)
	{
		TSharedPtr<ILevelEditor> LevelEditor = Module->GetFirstLevelEditor();
		if (LevelEditor.IsValid())
		{
			const TArray< TSharedPtr<ILevelViewport> >& LevelViewports = LevelEditor->GetViewports();
		
			for (int32 i = 0; i < LevelViewports.Num(); ++i)
			{
				const TSharedPtr<ILevelViewport>& LevelViewport = LevelViewports[i];

				TSharedPtr<SWidget>* TransportControl = TransportControls.Find(LevelViewport);
				if (TransportControl && TransportControl->IsValid())
				{
					LevelViewport->RemoveOverlayWidget(TransportControl->ToSharedRef());
				}
			}
		}
	}
}

EVisibility FSequencerAssetEditor::GetTransportControlVisibility(TWeakPtr<ILevelViewport> LevelViewport) const
{
	TSharedPtr<ILevelViewport> LevelViewportPin = LevelViewport.Pin();

	FLevelEditorViewportClient& ViewportClient = LevelViewportPin->GetLevelViewportClient();
	return (ViewportClient.IsPerspective() && ViewportClient.AllowMatineePreview()) ? EVisibility::Visible : EVisibility::Collapsed;
}



#undef LOCTEXT_NAMESPACE