OLS/Source/ols/Public/Components/OLSHealthComponent.h

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

#pragma once

#include "CoreMinimal.h"
#include "Components/GameFrameworkComponent.h"
#include "OLSHealthComponent.generated.h"

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FOLSDeathEventDynamicDelegate, class AActor*, owningActor);
DECLARE_MULTICAST_DELEGATE_OneParam(FOLSDeathEventNativeDelegate, class AActor* /* owningActor */)
DECLARE_DYNAMIC_MULTICAST_DELEGATE_FourParams(FOLSAttributeChangedDynamicDelegate, class UOLSHealthComponent*, healthComponent, float, oldValue, float, newValue, class AActor*, instigator);
DECLARE_MULTICAST_DELEGATE_FourParams(FOLSAttributeChangedNativeDelegate, class UOLSHealthComponent* /* healthComponent */, float /* oldValue */, float /* newValue */, class AActor* /* instigator */)

DECLARE_LOG_CATEGORY_EXTERN(LogOLSHealthComponent, Verbose, All);

/**
 *	EOLSDeathState
 *
 *	Defines current state of death.
 */
UENUM(BlueprintType)
enum class EOLSDeathState : uint8
{
	NotDead = 0,
	DeathStarted,
	DeathFinished
};

/**
 *	UOLSHealthComponent
 *
 *	An actor component used to handle anything related to health.
 */
UCLASS(Blueprintable, Meta=(BlueprintSpawnableComponent))
class OLS_API UOLSHealthComponent : public UGameFrameworkComponent
{
	GENERATED_BODY()

public:
	
	// Sets default values for this component's properties
	UOLSHealthComponent(const FObjectInitializer& objectInitializer);

	//~ Begin UActorComponent interface.
	virtual void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;
	//~ End UActorComponent interface.

	// Returns the health component if one exists on the specified actor.
	UFUNCTION(BlueprintPure, Category = "OLS|Health")
	static class UOLSHealthComponent* FindHealthComponent(const AActor* actor);

	// Initialize the component using an ability system component.
	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	void InitializeWithAbilitySystem(class UOLSAbilitySystemComponent* asc);

	// Uninitialize the component, clearing any references to the ability system.
	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	void UninitializeFromAbilitySystem();

	// Returns the current health value.
	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	float GetHealth() const;

	// Returns the current maximum health value.
	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	float GetMaxHealth() const;

	// Returns the current health in the range [0.0, 1.0].
	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	float GetHealthNormalized() const;

	UFUNCTION(BlueprintCallable, Category = "OLS|Health")
	EOLSDeathState GetDeathState() const;

	UFUNCTION(BlueprintCallable, BlueprintPure = false, Category = "OLS|Health", Meta = (ExpandBoolAsExecs = "ReturnValue"))
	bool IsDeadOrDying() const;

	// Begins the death sequence for the owner.
	virtual void StartDeath();

	// Ends the death sequence for the owner.
	virtual void FinishDeath();

	// Applies enough damage to kill the owner.
	virtual void DamageSelfDestruct(bool isFellOutOfWorld = false);
	
public:

	// Delegate fired when the health value has changed. This is called on the client but the instigator may not be valid
	UPROPERTY(BlueprintAssignable)
	FOLSAttributeChangedDynamicDelegate OnHealthChangedDynamicDelegate;
	FOLSAttributeChangedNativeDelegate OnHealthChangedNativeDelegate;

	// Delegate fired when the max health value has changed. This is called on the client but the instigator may not be valid
	UPROPERTY(BlueprintAssignable)
	FOLSAttributeChangedDynamicDelegate OnMaxHealthChangedDynamicDelegate;
	FOLSAttributeChangedNativeDelegate OnMaxHealthChangedNativeDelegate;

	// Delegate fired when the death sequence has started.
	UPROPERTY(BlueprintAssignable)
	FOLSDeathEventDynamicDelegate OnDeathStartedDynamicDelegate;
	FOLSDeathEventNativeDelegate OnDeathStartNativeDelegate;

	// Delegate fired when the death sequence has finished.
	UPROPERTY(BlueprintAssignable)
	FOLSDeathEventDynamicDelegate OnDeathFinishedDynamicDelegate;
	FOLSDeathEventNativeDelegate OnDeathFinishedNativeDelegate;

	void Broadcast_OnHealthChanged(UOLSHealthComponent* healthComponent, float oldValue, float newValue, AActor* instigator) const;
	void Broadcast_OnMaxHealthChanged(UOLSHealthComponent* healthComponent, float oldValue, float newValue, AActor* instigator) const;
	void Broadcast_OnDeathStarted(class AActor* owningActor) const;
	void Broadcast_OnDeathFinished(class AActor* owningActor) const;

protected:

	virtual void OnUnregister() override;

	void ClearGameplayTags();

	virtual void HandleHealthChanged(AActor* damageInstigator, AActor* damageCauser, const struct FGameplayEffectSpec* damageEffectSpec, float damageMagnitude, float oldValue, float newValue);
	virtual void HandleMaxHealthChanged(AActor* damageInstigator, AActor* damageCauser, const struct FGameplayEffectSpec* damageEffectSpec, float damageMagnitude, float dldValue, float newValue);
	virtual void HandleOutOfHealth(AActor* damageInstigator, AActor* damageCauser, const struct FGameplayEffectSpec* damageEffectSpec, float damageMagnitude, float oldValue, float newValue);

	UFUNCTION()
	virtual void OnRep_DeathState(EOLSDeathState oldDeathState = EOLSDeathState::NotDead);
	
protected:

	// Ability system used by this component.
	UPROPERTY()
	TObjectPtr<class UOLSAbilitySystemComponent> AbilitySystemComponent = nullptr;

	// Health set used by this component.
	UPROPERTY()
	TObjectPtr<const class UOLSHealthAttributeSet> HealthSet = nullptr;

	// Replicated state used to handle dying.
	UPROPERTY(ReplicatedUsing = OnRep_DeathState)
	EOLSDeathState DeathState = EOLSDeathState::NotDead;
};