RealtimeStyleTransferRuntime/Source/LyraGame/AbilitySystem/Attributes/LyraHealthSet.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "LyraHealthSet.h"
#include "LyraGameplayTags.h"
#include "Net/UnrealNetwork.h"
#include "AbilitySystem/LyraAbilitySystemComponent.h"
#include "GameplayEffectExtension.h"
#include "GameplayEffectTypes.h"
#include "Messages/LyraVerbMessage.h"
#include "GameFramework/GameplayMessageSubsystem.h"

UE_DEFINE_GAMEPLAY_TAG(TAG_Gameplay_Damage, "Gameplay.Damage");
UE_DEFINE_GAMEPLAY_TAG(TAG_Gameplay_DamageImmunity, "Gameplay.DamageImmunity");
UE_DEFINE_GAMEPLAY_TAG(TAG_Gameplay_DamageSelfDestruct, "Gameplay.Damage.SelfDestruct");
UE_DEFINE_GAMEPLAY_TAG(TAG_Gameplay_FellOutOfWorld, "Gameplay.Damage.FellOutOfWorld");
UE_DEFINE_GAMEPLAY_TAG(TAG_Lyra_Damage_Message, "Lyra.Damage.Message");

ULyraHealthSet::ULyraHealthSet()
	: Health(100.0f)
	, MaxHealth(100.0f)
{
	bOutOfHealth = false;
}

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

	DOREPLIFETIME_CONDITION_NOTIFY(ULyraHealthSet, Health, COND_None, REPNOTIFY_Always);
	DOREPLIFETIME_CONDITION_NOTIFY(ULyraHealthSet, MaxHealth, COND_None, REPNOTIFY_Always);
}

void ULyraHealthSet::OnRep_Health(const FGameplayAttributeData& OldValue)
{
	GAMEPLAYATTRIBUTE_REPNOTIFY(ULyraHealthSet, Health, OldValue);
}

void ULyraHealthSet::OnRep_MaxHealth(const FGameplayAttributeData& OldValue)
{
	GAMEPLAYATTRIBUTE_REPNOTIFY(ULyraHealthSet, MaxHealth, OldValue);
}

bool ULyraHealthSet::PreGameplayEffectExecute(FGameplayEffectModCallbackData &Data)
{
	if (!Super::PreGameplayEffectExecute(Data))
	{
		return false;
	}

	if (Data.EvaluatedData.Attribute == GetHealthAttribute())
	{
		if (Data.EvaluatedData.Magnitude < 0.0f)
		{
			const bool bIsDamageFromSelfDestruct = Data.EffectSpec.GetDynamicAssetTags().HasTagExact(TAG_Gameplay_DamageSelfDestruct);

			if (Data.Target.HasMatchingGameplayTag(TAG_Gameplay_DamageImmunity) && !bIsDamageFromSelfDestruct)
			{
				// Do not take away any health.
				Data.EvaluatedData.Magnitude = 0.0f;
				return false;
			}

#if !UE_BUILD_SHIPPING
			// Check GodMode cheat.
			if (Data.Target.HasMatchingGameplayTag(FLyraGameplayTags::Get().Cheat_GodMode) && !bIsDamageFromSelfDestruct)
			{
				// Do not take away any health.
				Data.EvaluatedData.Magnitude = 0.0f;
				return false;
			}

			// Check UnlimitedHealth cheat.
			if (Data.Target.HasMatchingGameplayTag(FLyraGameplayTags::Get().Cheat_UnlimitedHealth) && !bIsDamageFromSelfDestruct)
			{
				// Do not drop below 1 health.
				Data.EvaluatedData.Magnitude = FMath::Max(Data.EvaluatedData.Magnitude, (-GetHealth() + 1.0f));
			}
#endif // #if !UE_BUILD_SHIPPING
		}
	}

	return true;
}

void ULyraHealthSet::PostGameplayEffectExecute(const FGameplayEffectModCallbackData& Data)
{
	Super::PostGameplayEffectExecute(Data);

	if (Data.EvaluatedData.Attribute == GetHealthAttribute())
	{
		// Send a standardized verb message that other systems can observe
		if (Data.EvaluatedData.Magnitude < 0.0f)
		{
			FLyraVerbMessage Message;
			Message.Verb = TAG_Lyra_Damage_Message;
			Message.Instigator = Data.EffectSpec.GetEffectContext().GetEffectCauser();
			Message.InstigatorTags = *Data.EffectSpec.CapturedSourceTags.GetAggregatedTags();
			Message.Target = GetOwningActor();
			Message.TargetTags = *Data.EffectSpec.CapturedTargetTags.GetAggregatedTags();
			//@TODO: Fill out context tags, and any non-ability-system source/instigator tags
			//@TODO: Determine if it's an opposing team kill, self-own, team kill, etc...
			Message.Magnitude = Data.EvaluatedData.Magnitude;

			UGameplayMessageSubsystem& MessageSystem = UGameplayMessageSubsystem::Get(GetWorld());
			MessageSystem.BroadcastMessage(Message.Verb, Message);
		}

		if ((GetHealth() <= 0.0f) && !bOutOfHealth)
		{
			if (OnOutOfHealth.IsBound())
			{
				const FGameplayEffectContextHandle& EffectContext = Data.EffectSpec.GetEffectContext();
				AActor* Instigator = EffectContext.GetOriginalInstigator();
				AActor* Causer = EffectContext.GetEffectCauser();

				OnOutOfHealth.Broadcast(Instigator, Causer, Data.EffectSpec, Data.EvaluatedData.Magnitude);
			}
		}

		// Check health again in case an event above changed it.
		bOutOfHealth = (GetHealth() <= 0.0f);
	}
	else if (Data.EvaluatedData.Attribute == GetHealingAttribute())
	{
		SetHealth(GetHealth() + GetHealing());
		SetHealing(0.0f);
	}
}

void ULyraHealthSet::PreAttributeBaseChange(const FGameplayAttribute& Attribute, float& NewValue) const
{
	Super::PreAttributeBaseChange(Attribute, NewValue);

	ClampAttribute(Attribute, NewValue);
}

void ULyraHealthSet::PreAttributeChange(const FGameplayAttribute& Attribute, float& NewValue)
{
	Super::PreAttributeChange(Attribute, NewValue);

	ClampAttribute(Attribute, NewValue);
}

void ULyraHealthSet::PostAttributeChange(const FGameplayAttribute& Attribute, float OldValue, float NewValue)
{
	Super::PostAttributeChange(Attribute, OldValue, NewValue);

	if (Attribute == GetMaxHealthAttribute())
	{
		// Make sure current health is not greater than the new max health.
		if (GetHealth() > NewValue)
		{
			ULyraAbilitySystemComponent* LyraASC = GetLyraAbilitySystemComponent();
			check(LyraASC);

			LyraASC->ApplyModToAttribute(GetHealthAttribute(), EGameplayModOp::Override, NewValue);
		}
	}

	if (bOutOfHealth && (GetHealth() > 0.0f))
	{
		bOutOfHealth = false;
	}
}

void ULyraHealthSet::ClampAttribute(const FGameplayAttribute& Attribute, float& NewValue) const
{
	if (Attribute == GetHealthAttribute())
	{
		// Do not allow health to go negative or above max health.
		NewValue = FMath::Clamp(NewValue, 0.0f, GetMaxHealth());
	}
	else if (Attribute == GetMaxHealthAttribute())
	{
		// Do not allow max health to drop below 1.
		NewValue = FMath::Max(NewValue, 1.0f);
	}
}