// Copyright 2025 https://yuewu.dev/en  All Rights Reserved.


#include "Targeting/GCS_TargetingSystemComponent.h"

#include "GCS_LogChannels.h"
#include "Kismet/KismetMathLibrary.h"
#include "Camera/CameraComponent.h"
#include "GameFramework/Character.h"
#include "Camera/PlayerCameraManager.h"
#include "Net/UnrealNetwork.h"
#include "TargetingSystem/TargetingSubsystem.h"

UGCS_TargetingSystemComponent::UGCS_TargetingSystemComponent(const FObjectInitializer& ObjectInitializer) : Super(ObjectInitializer)
{
	PrimaryComponentTick.bCanEverTick = true;
	SetIsReplicatedByDefault(true);
}

UGCS_TargetingSystemComponent* UGCS_TargetingSystemComponent::GetTargetingSystemComponent(const AActor* Actor)
{
	return Actor ? Actor->FindComponentByClass<UGCS_TargetingSystemComponent>() : nullptr;
}

void UGCS_TargetingSystemComponent::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const
{
	Super::GetLifetimeReplicatedProps(OutLifetimeProps);

	DOREPLIFETIME_CONDITION(ThisClass, TargetedActor, COND_OwnerOnly);
}


// Called when the game starts
void UGCS_TargetingSystemComponent::BeginPlay()
{
	Super::BeginPlay();

	// ...
}


// Called every frame
void UGCS_TargetingSystemComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

	RefreshTargeting(DeltaTime);
}

void UGCS_TargetingSystemComponent::RefreshTargeting(float DeltaTime)
{
	if (GetOwnerRole() >= ROLE_AutonomousProxy)
	{
		if (bAutoUpdatePotentialTargets || IsValid(TargetedActor))
		{
			RefreshPotentialTargets();
		}

		bool LocalBool = PotentialTargets.Contains(TargetedActor);

		// Current TargetedActor no longer consider valid.
		if (TargetedActor && !LocalBool)
		{
			OnLockOff();
			SetTargetedActor(nullptr);
		}
	}
}

void UGCS_TargetingSystemComponent::SearchForActorToTarget()
{
	RefreshPotentialTargets();
	SelectFromPotentialTargets();
	//No target found/unlocked.
	if (!IsValid(TargetedActor) && !bAutoUpdatePotentialTargets)
	{
		PotentialTargets.Empty();
	}
}

AActor* UGCS_TargetingSystemComponent::SelectClosestActorFromPotentialTargets(float Radius) const
{
	// 检查 Owner 是否有效
	if (!GetOwner())
	{
		UE_LOG(LogTemp, Warning, TEXT("SelectClosestActorFromPotentialTargets: Owner is null"));
		return nullptr;
	}

	// 检查 PotentialTargets 是否为空
	if (PotentialTargets.Num() == 0)
	{
		return nullptr;
	}

	// 过滤有效 Actor 并在范围内
	TArray<AActor*> FilteredPotentialTargets;
	const FVector OwnerLocation = GetOwner()->GetActorLocation();

	for (AActor* Actor : PotentialTargets)
	{
		// 检查 Actor 是否有效且未被销毁
		if (IsValid(Actor))
		{
			float Distance = FVector::Dist(OwnerLocation, Actor->GetActorLocation());
			if (Distance <= Radius)
			{
				FilteredPotentialTargets.Add(Actor);
			}
		}
	}

	// 如果过滤后没有有效目标
	if (FilteredPotentialTargets.Num() == 0)
	{
		return nullptr;
	}

	// 寻找最近的 Actor
	AActor* ClosestActor = FilteredPotentialTargets[0];
	float MinDistance = FVector::Dist(OwnerLocation, ClosestActor->GetActorLocation());

	for (int32 i = 1; i < FilteredPotentialTargets.Num(); ++i)
	{
		AActor* CurrentActor = FilteredPotentialTargets[i];
		if (IsValid(CurrentActor))
		{
			float Distance = FVector::Dist(OwnerLocation, CurrentActor->GetActorLocation());
			if (Distance < MinDistance)
			{
				MinDistance = Distance;
				ClosestActor = CurrentActor;
			}
		}
	}

	return ClosestActor;
}

bool UGCS_TargetingSystemComponent::FilterActorsWithPreset(UTargetingPreset* InTargetingPreset, const TArray<AActor*> InTargets, TArray<AActor*>& OutActors)
{
	if (InTargetingPreset == nullptr)
	{
		return false;
	}

	if (UTargetingSubsystem* TargetingSubsystem = UTargetingSubsystem::Get(GetWorld()))
	{
		FTargetingSourceContext SourceContext;
		SourceContext.SourceActor = GetOwner();

		FTargetingRequestHandle TargetingHandle = UTargetingSubsystem::MakeTargetRequestHandle(TargetingPreset, SourceContext);

		if (TargetingHandle.IsValid() && InTargets.Num() > 0)
		{
			FTargetingDefaultResultsSet& TargetingResults = FTargetingDefaultResultsSet::FindOrAdd(TargetingHandle);
			for (AActor* Target : InTargets)
			{
				if (!Target)
				{
					continue;
				}

				bool bAddResult = !TargetingResults.TargetResults.ContainsByPredicate([Target](const FTargetingDefaultResultData& Data) -> bool
				{
					return (Data.HitResult.GetActor() == Target);
				});

				if (bAddResult)
				{
					FTargetingDefaultResultData* ResultData = new(TargetingResults.TargetResults) FTargetingDefaultResultData();
					ResultData->HitResult.HitObjectHandle = FActorInstanceHandle(Target);
					ResultData->HitResult.Location = Target->GetActorLocation();
				}
			}
		}


		FTargetingRequestDelegate Delegate = FTargetingRequestDelegate::CreateWeakLambda(this, [&](FTargetingRequestHandle InTargetingHandle)
		{
			TargetingSubsystem->GetTargetingResultsActors(InTargetingHandle, OutActors);
		});

		FTargetingImmediateTaskData& ImmeidateTaskData = FTargetingImmediateTaskData::FindOrAdd(TargetingHandle);
		ImmeidateTaskData.bReleaseOnCompletion = true;

		TargetingSubsystem->ExecuteTargetingRequestWithHandle(TargetingHandle, Delegate);
	}

	return !OutActors.IsEmpty();
}

void UGCS_TargetingSystemComponent::SetTargetedActor(AActor* NewActor)
{
	SetTargetedActor(NewActor, true);
}

void UGCS_TargetingSystemComponent::SetTargetedActor(AActor* NewActor, bool bSendRpc)
{
	if (GetOwnerRole() < ROLE_AutonomousProxy)
	{
		return;
	}

	if (bSendRpc)
	{
		if (GetOwnerRole() >= ROLE_Authority)
		{
			ClientSetTargetedActor(NewActor);
		}
		else
		{
			ServerSetTargetedActor(NewActor);
		}
	}

	TargetedActor = NewActor;
}

void UGCS_TargetingSystemComponent::ClientSetTargetedActor_Implementation(AActor* NewActor)
{
	SetTargetedActor(NewActor, false);
}

void UGCS_TargetingSystemComponent::ServerSetTargetedActor_Implementation(AActor* NewActor)
{
	SetTargetedActor(NewActor, false);
}

void UGCS_TargetingSystemComponent::OnLockOff_Implementation()
{
	OnTargetLockOffEvent.Broadcast(TargetedActor);
}

void UGCS_TargetingSystemComponent::OnLockOn_Implementation()
{
	OnTargetLockOnEvent.Broadcast(TargetedActor);
}

void UGCS_TargetingSystemComponent::SelectFromPotentialTargets()
{
	if (!IsValid(TargetedActor))
	{
		TMap<AActor*, float> LocalPotentialTargets;

		for (TObjectPtr<AActor>& Elem : PotentialTargets)
		{
			if (CanBeTargeted(Elem))
			{
				LocalPotentialTargets.Add(Elem, UKismetMathLibrary::Abs(CalculateViewAngle(Elem)));
			}
		}

		if (LocalPotentialTargets.Num() > 0)
		{
			TArray<AActor*> LocalTargets;
			TArray<float> LocalAngles;
			LocalPotentialTargets.GenerateKeyArray(LocalTargets);
			LocalPotentialTargets.GenerateValueArray(LocalAngles);

			int32 MinIndex;
			const float MaxValue = FMath::Min<float>(LocalAngles, &MinIndex);
			SetTargetedActor(LocalTargets[MinIndex]);
			OnLockOn();
		}
	}
	else
	{
		OnLockOff();
		SetTargetedActor(nullptr);
	}
}

void UGCS_TargetingSystemComponent::RefreshPotentialTargets()
{
	DECLARE_SCOPE_CYCLE_COUNTER(TEXT("UGCS_TargetingSystemComponent::RefreshPotentialTargets"), UGCS_TargetingSystemComponent_RefreshPotentialTargets, STATGROUP_GCS)
	TRACE_CPUPROFILER_EVENT_SCOPE_STR(__FUNCTION__)
	if (TargetingPreset == nullptr)
	{
		return;
	}

	if (UTargetingSubsystem* TargetingSubsystem = UTargetingSubsystem::Get(GetWorld()))
	{
		FTargetingSourceContext SourceContext;
		SourceContext.SourceActor = GetOwner();
		SourceContext.SourceObject = this;

		FTargetingRequestHandle TargetingHandle = UTargetingSubsystem::MakeTargetRequestHandle(TargetingPreset, SourceContext);
		FTargetingRequestDelegate Delegate = FTargetingRequestDelegate::CreateWeakLambda(this, [this,TargetingSubsystem](FTargetingRequestHandle InTargetingHandle)
		{
			TArray<AActor*> Results;
			TargetingSubsystem->GetTargetingResultsActors(InTargetingHandle, Results);
			PotentialTargets.Empty();
			PotentialTargets = Results;
		});

		if (bUseAsyncTargeting)
		{
			FTargetingAsyncTaskData& AsyncTaskData = FTargetingAsyncTaskData::FindOrAdd(TargetingHandle);
			AsyncTaskData.bReleaseOnCompletion = true;

			TargetingSubsystem->StartAsyncTargetingRequestWithHandle(TargetingHandle, Delegate);
		}
		else
		{
			FTargetingImmediateTaskData& ImmeidateTaskData = FTargetingImmediateTaskData::FindOrAdd(TargetingHandle);
			ImmeidateTaskData.bReleaseOnCompletion = true;

			TargetingSubsystem->ExecuteTargetingRequestWithHandle(TargetingHandle, Delegate);
		}
	}
}

bool UGCS_TargetingSystemComponent::CanBeTargeted_Implementation(AActor* ActorToTarget)
{
	return true;
}


void UGCS_TargetingSystemComponent::StaticSwitchToNewTarget(bool RightDirection)
{
	if (TargetedActor)
	{
		TMap<AActor*, float> LocalPotentialTargets;

		for (TObjectPtr<AActor>& Elem : PotentialTargets)
		{
			if (Elem != TargetedActor)
			{
				float LocalDistance = UKismetMathLibrary::Vector_Distance(GetOwner()->GetActorLocation(), Elem->GetActorLocation());

				FRotator RequiredRotation = UKismetMathLibrary::FindLookAtRotation(GetOwner()->GetActorLocation(), Elem->GetActorLocation());
				FRotator DeltaRotation;

				ACharacter* LocalOwnerCharacter = Cast<ACharacter>(GetOwner());

				DeltaRotation = UKismetMathLibrary::NormalizedDeltaRotator(LocalOwnerCharacter->GetControlRotation(), RequiredRotation);

				if (RightDirection == 1)
				{
					if (DeltaRotation.Yaw < 0.f && DeltaRotation.Yaw > -100.f)
					{
						LocalPotentialTargets.Add(Elem, DeltaRotation.Yaw);
					}
					else
					{
						LocalPotentialTargets.Add(Elem, -10000.f);
					}
				}
				else
				{
					if (DeltaRotation.Yaw > 0.f && DeltaRotation.Yaw < 100.f)
					{
						LocalPotentialTargets.Add(Elem, DeltaRotation.Yaw);
					}
					else
					{
						LocalPotentialTargets.Add(Elem, 10000.f);
					}
				}
			}
		}

		if (LocalPotentialTargets.Num() > 0)
		{
			TArray<AActor*> LocalTargets;
			TArray<float> LocalAngles;
			LocalPotentialTargets.GenerateKeyArray(LocalTargets);
			LocalPotentialTargets.GenerateValueArray(LocalAngles);

			if (RightDirection == 1)
			{
				int32 FoundIndex;
				const float MaxValue = FMath::Max<float>(LocalAngles, &FoundIndex);
				if (MaxValue > -10000.f)
				{
					OnLockOff();
					SetTargetedActor(LocalTargets[FoundIndex]);
					OnLockOn();
				}
			}
			else
			{
				int32 FoundIndex;
				const float MinValue = FMath::Min<float>(LocalAngles, &FoundIndex);
				if (MinValue < 10000.f)
				{
					OnLockOff();
					SetTargetedActor(LocalTargets[FoundIndex]);
					OnLockOn();
				}
			}
		}
	}
}


float UGCS_TargetingSystemComponent::CalculateViewAngle(const AActor* TargetActor)
{
	APawn* OwningPawn = GetPawn<APawn>();
	FRotator FinalRotation = FRotator::ZeroRotator;
	if (TargetActor && OwningPawn)
	{
		FRotator RequiredRotation = UKismetMathLibrary::FindLookAtRotation(OwningPawn->GetPawnViewLocation(), TargetActor->GetActorLocation());

		FRotator DeltaRotation = UKismetMathLibrary::NormalizedDeltaRotator(RequiredRotation, OwningPawn->GetViewRotation());
		FinalRotation = DeltaRotation;
	}

	return UKismetMathLibrary::Abs(UKismetMathLibrary::Abs(FinalRotation.Yaw) + UKismetMathLibrary::Abs(FinalRotation.Pitch));
}