// Portage UE 5.5 - voir LPSecondScreenSubsystem.h

#include "LPSecondScreenSubsystem.h"

#include "Components/CapsuleComponent.h"
#include "Components/SceneCaptureComponent2D.h"
#include "Components/SkeletalMeshComponent.h"
#include "Engine/GameInstance.h"
#include "Engine/SceneCapture2D.h"
#include "Engine/World.h"
#include "EngineUtils.h"
#include "GameFramework/Character.h"
#include "LifePlay.h"
#include "UObject/UnrealType.h"

namespace
{
	// Cadrage du visage : distance camera-tete (cm) et champ horizontal (degres).
	constexpr float FaceDistance = 80.f;
	constexpr float FaceFOV = 30.f;
	const FName CaptureActorName(TEXT("SecondScreen"));
	const FName PersonPropertyName(TEXT("SecondScreenPerson"));
	const FName HeadSocket(TEXT("head"));

	/** Position de la tete : os "head" du premier maillage qui le porte, sinon haut de la capsule. */
	FVector HeadLocation(const AActor* Person)
	{
		TInlineComponentArray<USkeletalMeshComponent*> Meshes(Person);
		for (const USkeletalMeshComponent* Mesh : Meshes)
		{
			if (Mesh && Mesh->GetSkinnedAsset() && Mesh->DoesSocketExist(HeadSocket))
			{
				return Mesh->GetSocketLocation(HeadSocket);
			}
		}
		if (const ACharacter* Character = Cast<ACharacter>(Person))
		{
			if (const UCapsuleComponent* Capsule = Character->GetCapsuleComponent())
			{
				return Capsule->GetComponentLocation() + FVector(0.f, 0.f, Capsule->GetScaledCapsuleHalfHeight() * 0.8f);
			}
		}
		return Person->GetActorLocation();
	}
}

void ULPSecondScreenSubsystem::Initialize(FSubsystemCollectionBase& Collection)
{
	Super::Initialize(Collection);
	TickHandle = FTSTicker::GetCoreTicker().AddTicker(FTickerDelegate::CreateUObject(this, &ULPSecondScreenSubsystem::Tick));
}

void ULPSecondScreenSubsystem::Deinitialize()
{
	FTSTicker::GetCoreTicker().RemoveTicker(TickHandle);
	Super::Deinitialize();
}

bool ULPSecondScreenSubsystem::Tick(float DeltaTime)
{
	const UGameInstance* GI = GetGameInstance();
	UWorld* World = GI ? GI->GetWorld() : nullptr;
	if (!World)
	{
		return true;
	}

	// La camera est recherchee une fois par monde (par nom d'objet : l'etiquette n'existe pas en Shipping).
	if (CaptureWorld.Get() != World)
	{
		CaptureWorld = World;
		Capture.Reset();
		for (TActorIterator<ASceneCapture2D> It(World); It; ++It)
		{
			if (It->GetFName() == CaptureActorName)
			{
				Capture = *It;
				break;
			}
		}
	}
	ASceneCapture2D* CaptureActor = Capture.Get();
	USceneCaptureComponent2D* CaptureComp = CaptureActor ? CaptureActor->GetCaptureComponent2D() : nullptr;
	if (!CaptureComp)
	{
		return true;
	}

	const FObjectPropertyBase* Prop = CastField<FObjectPropertyBase>(GI->GetClass()->FindPropertyByName(PersonPropertyName));
	const AActor* Person = Prop ? Cast<AActor>(Prop->GetObjectPropertyValue_InContainer(GI)) : nullptr;
	if (!IsValid(Person))
	{
		return true;
	}

	const FVector Head = HeadLocation(Person);
	FVector Forward = Person->GetActorForwardVector();
	Forward.Z = 0.f;
	if (!Forward.Normalize())
	{
		Forward = FVector::ForwardVector;
	}
	const FVector CameraLocation = Head + Forward * FaceDistance;
	if (CaptureComp->Mobility != EComponentMobility::Movable)
	{
		// Composant pose dans la carte : un composant statique refuse d'etre deplace en jeu.
		CaptureComp->SetMobility(EComponentMobility::Movable);
	}
	CaptureComp->SetWorldLocationAndRotation(CameraLocation, (Head - CameraLocation).Rotation());
	CaptureComp->FOVAngle = FaceFOV;
	return true;
}