#include "PlayerControllerBase.h"
#include "Common.h"
#include "Tangible.h"
#include "TangibleManager.h"
#include "Components/InputComponent.h"
#include "Engine/LevelScriptActor.h"
#include "Kismet/GameplayStatics.h"
#include "Engine/GameInstance.h"

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::PushInputComponent(UInputComponent* InInputComponent)
{
	if (InInputComponent)
	{
		CurrentInputStack.RemoveSingle(InInputComponent);
		CurrentInputStack.Add(InInputComponent);
	}
}

bool AlxPlayerControllerBase::PopInputComponent(UInputComponent* InInputComponent)
{
	if (InInputComponent)
	{
		if (CurrentInputStack.RemoveSingle(InInputComponent) > 0)
		{
			InInputComponent->ClearBindingValues();
			return true;
		}
	}
	return false;
}

void AlxPlayerControllerBase::BuildInputStack(TArray<UInputComponent*>& InputStack)
{
	// Controlled pawn gets last dibs on the input stack
	APawn* ControlledPawn = GetPawnOrSpectator();
	if (ControlledPawn)
	{
		if (ControlledPawn->InputEnabled())
		{
			// Get the explicit input component that is created upon Pawn possession. This one gets last dibs.
			if (ControlledPawn->InputComponent)
			{
				InputStack.Push(ControlledPawn->InputComponent);
			}

			// See if there is another InputComponent that was added to the Pawn's components array (possibly by script).
			for (UActorComponent* ActorComponent : ControlledPawn->GetComponents())
			{
				UInputComponent* PawnInputComponent = Cast<UInputComponent>(ActorComponent);
				if (PawnInputComponent && PawnInputComponent != ControlledPawn->InputComponent)
				{
					InputStack.Push(PawnInputComponent);
				}
			}
		}
	}

	// LevelScriptActors are put on the stack next
	for (ULevel* Level : GetWorld()->GetLevels())
	{
		ALevelScriptActor* ScriptActor = Level->GetLevelScriptActor();
		if (ScriptActor)
		{
			if (ScriptActor->InputEnabled() && ScriptActor->InputComponent)
			{
				InputStack.Push(ScriptActor->InputComponent);
			}
		}
	}

	if (InputEnabled())
	{
		InputStack.Push(InputComponent);
	}

	// Sort the components first by bBlockInput, then by
	// priority. We don't touch the original array, because
	// we want to preserve information about which component
	// was pushed last.
	TArray<UInputComponent*, TInlineAllocator<20>> Pushed;
	for (int32 Idx = 0; Idx < CurrentInputStack.Num(); ++Idx)
	{
		UInputComponent* IC = CurrentInputStack[Idx].Get();
		if (IsValid(IC))
		{
			Pushed.Add(IC);
		}
		else
		{
			CurrentInputStack.RemoveAt(Idx--);
		}
	}

	Pushed.StableSort([](const UInputComponent& A, const UInputComponent& B)
	{
		if (A.bBlockInput != B.bBlockInput) return !A.bBlockInput;
		return A.Priority < B.Priority;
	});

	InputStack.Append(Pushed);
}

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();
	}
}