// Portage UE 5.5 - voir LPRoomTransitionSubsystem.h

#include "LPRoomTransitionSubsystem.h"

#include "Components/SceneComponent.h"
#include "Engine/GameInstance.h"
#include "GameFramework/Actor.h"
#include "HAL/PlatformTime.h"
#include "LifePlay.h"
#include "UObject/UnrealType.h"

namespace
{
	constexpr double SafetySeconds = 10.0;

	template <typename T>
	T* GetObjectProperty(const UObject* Container, const TCHAR* Name)
	{
		const FObjectPropertyBase* Prop = Container ? CastField<FObjectPropertyBase>(Container->GetClass()->FindPropertyByName(Name)) : nullptr;
		return Prop ? Cast<T>(Prop->GetObjectPropertyValue_InContainer(Container)) : nullptr;
	}

	/** Contenu d'une variable tableau d'acteurs de GI (DummyPersonsInUse, PersonsUsedThisScene). */
	TArray<AActor*> GetActorArray(const UObject* Container, const TCHAR* Name)
	{
		TArray<AActor*> Result;
		const FArrayProperty* Prop = Container ? CastField<FArrayProperty>(Container->GetClass()->FindPropertyByName(Name)) : nullptr;
		const FObjectPropertyBase* Inner = Prop ? CastField<FObjectPropertyBase>(Prop->Inner) : nullptr;
		if (!Inner)
		{
			return Result;
		}
		FScriptArrayHelper Helper(Prop, Prop->ContainerPtrToValuePtr<void>(Container));
		for (int32 i = 0; i < Helper.Num(); ++i)
		{
			if (AActor* Actor = Cast<AActor>(Inner->GetObjectPropertyValue(Helper.GetRawPtr(i))))
			{
				Result.Add(Actor);
			}
		}
		return Result;
	}

	/** Valeur texte d'une variable de GI, quel que soit son type (chaine, nom, texte). */
	FString GetPropertyText(const UObject* Container, const TCHAR* Name)
	{
		FString Text;
		if (const FProperty* Prop = Container ? Container->GetClass()->FindPropertyByName(Name) : nullptr)
		{
			Prop->ExportTextItem_Direct(Text, Prop->ContainerPtrToValuePtr<void>(Container), nullptr, nullptr, PPF_None);
		}
		return Text;
	}
}

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

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

bool ULPRoomTransitionSubsystem::Tick(float DeltaTime)
{
	const UGameInstance* GI = GetGameInstance();
	const AActor* Room = GetObjectProperty<AActor>(GI, TEXT("Room"));
	const USceneComponent* Root = IsValid(Room) ? Room->GetRootComponent() : nullptr;
	if (!Root)
	{
		return true;
	}

	const TArray<AActor*> InUse = GetActorArray(GI, TEXT("DummyPersonsInUse"));
	const double Now = FPlatformTime::Seconds();

	// 1. Suivi des personnages caches : rendus a la reserve, reaffiches par le jeu, ou delai de securite depasse.
	for (auto It = Hidden.CreateIterator(); It; ++It)
	{
		AActor* Actor = It.Key().Get();
		if (!IsValid(Actor) || !InUse.Contains(Actor) || !Actor->IsHidden())
		{
			It.RemoveCurrent();
		}
		else if (Now - It.Value() > SafetySeconds)
		{
			Actor->SetActorHiddenInGame(false);
			UE_LOG(LogLifePlay, Log, TEXT("Changement de lieu : %s toujours actif apres %.0f s, reaffiche"), *Actor->GetName(), SafetySeconds);
			It.RemoveCurrent();
		}
	}

	// 2. Changement de piece : cacher les personnages actifs au tick precedent, sauf compagnon et scene en cours.
	const FString Signature = GetPropertyText(GI, TEXT("CurrentAmenity")) + TEXT("|") + Root->GetRelativeScale3D().ToString();
	if (!LastRoomSignature.IsEmpty() && Signature != LastRoomSignature)
	{
		const AActor* Companion = GetObjectProperty<AActor>(GI, TEXT("Companion"));
		const TArray<AActor*> ScenePersons = GetActorArray(GI, TEXT("PersonsUsedThisScene"));
		int32 Count = 0;
		for (const TWeakObjectPtr<AActor>& Weak : LastInUse)
		{
			AActor* Actor = Weak.Get();
			if (!IsValid(Actor) || Actor == Companion || ScenePersons.Contains(Actor) || Actor->IsHidden() || !InUse.Contains(Actor))
			{
				continue;
			}
			Actor->SetActorHiddenInGame(true);
			Hidden.Add(Actor, Now);
			++Count;
		}
		if (Count > 0)
		{
			UE_LOG(LogLifePlay, Log, TEXT("Changement de lieu (%s -> %s) : %d personnage(s) de la piece precedente caches"),
				*LastRoomSignature, *Signature, Count);
		}
	}
	LastRoomSignature = Signature;

	LastInUse.Reset(InUse.Num());
	for (AActor* Actor : InUse)
	{
		LastInUse.Add(Actor);
	}
	return true;
}