#include "PlayerControllerBase.h"
#include "Common.h"
#include "Tangible.h"
#include "TangibleManager.h"
#include "Kismet/GameplayStatics.h"
#include "Engine/GameInstance.h"
#include "Engine/GameViewportClient.h"
#include "Framework/Application/SlateApplication.h"
#include "Widgets/SViewport.h"
#include "Slate/SObjectWidget.h"

FString AlxPlayerControllerBase::GetUserWidgetName(SWidget *W)
{
	while (W)
	{
		if (W->GetType() == FName("SObjectWidget"))
		{
			UUserWidget *UW = static_cast<SObjectWidget*>(W)->GetWidgetObject();
			if (UW) return UW->GetClass()->GetName();
		}
		W = W->GetParentWidget().Get();
	}
	return TEXT("Unknown Widget");
}

AlxPlayerControllerBase *AlxPlayerControllerBase::FromContext(const UObject *Context)
{
	APlayerController *PC = Context->GetWorld()->GetFirstPlayerController();
	AlxPlayerControllerBase *Result = Cast<AlxPlayerControllerBase>(PC);
	if (Result == nullptr)
	{
		UE_LOG(LogLuprexIntegration, Fatal, TEXT("Not currently using a Luprex Player Controller."));
	}
	return Result;
}

const FHitResult &AlxPlayerControllerBase::GetLookAt(const UObject *Context)
{
	return FromContext(Context)->CurrentLookAt;
}

const AActor *AlxPlayerControllerBase::GetLookAtActor(const UObject *Context)
{
	return FromContext(Context)->CurrentLookAt.GetActor();
}

void AlxPlayerControllerBase::SetLookAt(const UObject *Context, const FHitResult &HitResult)
{
	AlxPlayerControllerBase *PC = FromContext(Context);
	if (PC->CurrentLookAt.HitObjectHandle != HitResult.HitObjectHandle)
	{
		PC->MustCallLookAtChanged = true;
	}
	PC->CurrentLookAt = HitResult;
}

void AlxPlayerControllerBase::SetLookAtChanged(const UObject *Context)
{
	AlxPlayerControllerBase *PC = FromContext(Context);
	PC->MustCallLookAtChanged = true;
}

FVector2D AlxPlayerControllerBase::GetLookAtPixel(const UObject *Context)
{
	AlxPlayerControllerBase *PC = FromContext(Context);
	FVector2D ScreenPosition;
	if (!UGameplayStatics::ProjectWorldToScreen(PC, PC->CurrentLookAt.Location, ScreenPosition, false))
	{
		return FVector2D();
	}
	return ScreenPosition;
}

void AlxPlayerControllerBase::BeginPlay()
{
	Super::BeginPlay();
	CharacterModeInput = NewObject<UInputComponent>(this);
	CharacterModeInput->bBlockInput = false;
	PushInputComponent(CharacterModeInput);
}

void AlxPlayerControllerBase::UpdateEventDispatch()
{
	EventRequests.GarbageCollect();

	// If we're in GameOnly mode, check that focus is still on the viewport.
	if (CurrentInputMode == InputMode::GameOnly)
	{
		UGameViewportClient *GVC = GetWorld() ? GetWorld()->GetGameViewport() : nullptr;
		if (GVC)
		{
			TSharedPtr<SViewport> ViewportWidget = GVC->GetGameViewportWidget();
			if (ViewportWidget.IsValid())
			{
				TSharedPtr<SWidget> Focused = FSlateApplication::Get().GetKeyboardFocusedWidget();
				if (Focused.Get() != ViewportWidget.Get())
				{
					UE_LOG(LogLuprexIntegration, Error, TEXT("In GameOnly mode, keyboard focus must stay on viewport, but was stolen by: %s.  Restoring."), *GetUserWidgetName(Focused.Get()));
					EventRequests.SetDirty();
				}
				if (!ViewportWidget->HasMouseCapture())
				{
					UE_LOG(LogLuprexIntegration, Error, TEXT("In GameOnly mode, viewport must have mouse capture, but lost it.  Restoring."));
					EventRequests.SetDirty();
				}
			}
		}
	}

	if (!EventRequests.IsDirty()) return;
	EventRequests.ClearDirty();

	CurrentInputMode = EventRequests.GetRequestedMode();
	const TArray<FlxEventRequest> &Requests = EventRequests.GetRequests();

	if (CurrentInputMode == InputMode::UIOnly)
	{
		SetInputMode(FInputModeUIOnly().SetWidgetToFocus(Requests[0].Widget->GetCachedWidget()));
	}
	else
	{
		SetInputMode(FInputModeGameOnly());

		CharacterModeInput->KeyBindings.Empty();
		TSet<FKey> BoundKeys;
		for (const FlxEventRequest &Req : Requests)
		{
			for (const FKey &Key : Req.Hotkeys)
			{
				if (!BoundKeys.Contains(Key))
				{
					BoundKeys.Add(Key);
					CharacterModeInput->BindKey(Key, IE_Pressed, this, &AlxPlayerControllerBase::ForwardKeyEvent);
				}
			}
		}
	}
}

void AlxPlayerControllerBase::ForwardKeyEvent(FKey Key)
{
	// TODO: implement
}


void AlxPlayerControllerBase::RequestEvents(const FlxEventRequest &Request)
{
	if (!FlxEventRequests::SanityCheck(Request)) return;
	AlxPlayerControllerBase *PC = FromContext(Request.Widget);
	PC->EventRequests.Request(Request);
}

void AlxPlayerControllerBase::UnRequestEvents(UUserWidget *Widget)
{
	if (Widget == nullptr)
	{
		UE_LOG(LogLuprexIntegration, Error, TEXT("UnRequestEvents called with null widget."));
		return;
	}
	AlxPlayerControllerBase *PC = FromContext(Widget);
	PC->EventRequests.Remove(Widget);
}

void AlxPlayerControllerBase::UpdateLookAt()
{
	UlxTangibleManager *TM = GetGameInstance()->GetSubsystem<UlxTangibleManager>();
	if (TM == nullptr) return;
	UlxTangible *Possessed = TM->GetPossessedTangible();
	if (Possessed == nullptr) return;
	APawn *Pawn = GetPawn();
	if (Pawn == nullptr) return;
	if (Possessed->GetActor() != Cast<AActor>(Pawn)) return;
	if (PlayerCameraManager == nullptr) return;

	CalculateLookAt();

	if (MustCallLookAtChanged)
	{
		MustCallLookAtChanged = false;
		LookAtChanged();
	}
}