OLS/Source/ols/Private/AbilitySystem/Attributes/OLSHealthAttributeSet.cpp

// © 2024 Long Ly. All rights reserved. Any unauthorized use, reproduction, or distribution of this trademark is strictly prohibited and may result in legal action.


#include "AbilitySystem/Attributes/OLSHealthAttributeSet.h"

#include "GameplayEffectExtension.h"
#include "AbilitySystem/OLSAbilitySystemComponent.h"
#include "GameFramework/GameplayMessageSubsystem.h"
#include "Messages/OLSVerbMessage.h"
#include "Net/UnrealNetwork.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_OLS_Damage_Message, "Lyra.Damage.Message");

UOLSHealthAttributeSet::UOLSHealthAttributeSet()
	: Health(100.0f)
	, MaxHealth(100.0f)
{
	bIsOutOfHealth = false;
	MaxHealthBeforeAttributeChange = 0.0f;
	HealthBeforeAttributeChange = 0.0f;
}

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

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

void UOLSHealthAttributeSet::OnRep_Health(const FGameplayAttributeData& oldValue)
{
	GAMEPLAYATTRIBUTE_REPNOTIFY(UOLSHealthAttributeSet, Health, oldValue);

	// Call the change callback, but without an instigator
	// This could be changed to an explicit RPC in the future
	// These events on the client should not be changing attributes

	const float currentHealth = GetHealth();
	const float estimatedMagnitude = currentHealth - oldValue.GetCurrentValue();
	
	OnHealthChanged.Broadcast(
		nullptr,
		nullptr,
		nullptr,
		estimatedMagnitude,
		oldValue.GetCurrentValue(),
		currentHealth);

	const bool isCurrentHealthEqualOrBelowZero = (currentHealth <= 0.0f);

	if (!bIsOutOfHealth && isCurrentHealthEqualOrBelowZero)
	{
		OnOutOfHealth.Broadcast(nullptr, nullptr, nullptr, estimatedMagnitude, oldValue.GetCurrentValue(), currentHealth);
	}

	bIsOutOfHealth = isCurrentHealthEqualOrBelowZero;
}

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

	// Call the change callback, but without an instigator
	// This could be changed to an explicit RPC in the future
	OnMaxHealthChanged.Broadcast(
		nullptr,
		nullptr,
		nullptr,
		GetMaxHealth() - OldValue.GetCurrentValue(),
		OldValue.GetCurrentValue(), GetMaxHealth());
}

bool UOLSHealthAttributeSet::PreGameplayEffectExecute(FGameplayEffectModCallbackData& data)
{
	if (!Super::PreGameplayEffectExecute(data))
	{
		return false;
	}

	// Handle modifying incoming normal damage
	if (data.EvaluatedData.Attribute == GetDamageAttribute())
	{
		if (data.EvaluatedData.Magnitude > 0.0f)
		{
			const bool isDamageFromSelfDestruct = data.EffectSpec.GetDynamicAssetTags().HasTagExact(TAG_Gameplay_DamageSelfDestruct);

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

#if !UE_BUILD_SHIPPING
			// Check GodMode cheat, unlimited health is checked below
			// if (data.Target.HasMatchingGameplayTag(LyraGameplayTags::Cheat_GodMode) && !isDamageFromSelfDestruct)
			// {
			// 	// Do not take away any health.
			// 	data.EvaluatedData.Magnitude = 0.0f;
			// 	return false;
			// }
#endif // #if !UE_BUILD_SHIPPING
		}
	}

	// Save the current health
	HealthBeforeAttributeChange = GetHealth();
	MaxHealthBeforeAttributeChange = GetMaxHealth();

	return true;
}

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

		const bool isDamageFromSelfDestruct = Data.EffectSpec.GetDynamicAssetTags().HasTagExact(TAG_Gameplay_DamageSelfDestruct);
	float minimumHealth = 0.0f;

#if !UE_BUILD_SHIPPING
	// Godmode and unlimited health stop death unless it's a self destruct
	// if (!bIsDamageFromSelfDestruct &&
	// 	(Data.Target.HasMatchingGameplayTag(LyraGameplayTags::Cheat_GodMode) || Data.Target.HasMatchingGameplayTag(LyraGameplayTags::Cheat_UnlimitedHealth) ))
	// {
	// 	MinimumHealth = 1.0f;
	// }
#endif // #if !UE_BUILD_SHIPPING

	const FGameplayEffectContextHandle& effectContext = Data.EffectSpec.GetEffectContext();
	AActor* instigator = effectContext.GetOriginalInstigator();
	AActor* causer = effectContext.GetEffectCauser();

	if (Data.EvaluatedData.Attribute == GetDamageAttribute())
	{
		// Send a standardized verb message that other systems can observe
		if (Data.EvaluatedData.Magnitude > 0.0f)
		{
			FOLSVerbMessage message;
			message.Verb = TAG_OLS_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);
		}

		// Convert into -Health and then clamp
		SetHealth(FMath::Clamp(GetHealth() - GetDamage(), minimumHealth, GetMaxHealth()));
		SetDamage(0.0f);
	}
	else if (Data.EvaluatedData.Attribute == GetHealingAttribute())
	{
		// Convert into +Health and then clamo
		SetHealth(FMath::Clamp(GetHealth() + GetHealing(), minimumHealth, GetMaxHealth()));
		SetHealing(0.0f);
	}
	else if (Data.EvaluatedData.Attribute == GetHealthAttribute())
	{
		// Clamp and fall into out of health handling below
		SetHealth(FMath::Clamp(GetHealth(), minimumHealth, GetMaxHealth()));
	}
	else if (Data.EvaluatedData.Attribute == GetMaxHealthAttribute())
	{
		// TODO clamp current health?

		// Notify on any requested max health changes
		OnMaxHealthChanged.Broadcast(instigator, causer, &Data.EffectSpec, Data.EvaluatedData.Magnitude, MaxHealthBeforeAttributeChange, GetMaxHealth());
	}

	// If health has actually changed activate callbacks
	if (GetHealth() != HealthBeforeAttributeChange)
	{
		OnHealthChanged.Broadcast(instigator, causer, &Data.EffectSpec, Data.EvaluatedData.Magnitude, HealthBeforeAttributeChange, GetHealth());
	}

	if ((GetHealth() <= 0.0f) && !bIsOutOfHealth)
	{
		OnOutOfHealth.Broadcast(instigator, causer, &Data.EffectSpec, Data.EvaluatedData.Magnitude, HealthBeforeAttributeChange, GetHealth());
	}

	// Check health again in case an event above changed it.
	bIsOutOfHealth = (GetHealth() <= 0.0f);
}

void UOLSHealthAttributeSet::PreAttributeBaseChange(const FGameplayAttribute& attribute, float& newValue) const
{
	Super::PreAttributeBaseChange(attribute, newValue);
	
	ClampAttribute(attribute, newValue);
}

void UOLSHealthAttributeSet::PreAttributeChange(const FGameplayAttribute& attribute, float& newValue)
{
	Super::PreAttributeChange(attribute, newValue);
	
	ClampAttribute(attribute, newValue);
}

void UOLSHealthAttributeSet::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)
		{
			UOLSAbilitySystemComponent* asc = GetOLSAbilitySystemComponent();
			check(asc);

			asc->ApplyModToAttribute(GetHealthAttribute(), EGameplayModOp::Override, newValue);
		}
	}

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

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