// Copyright (c) 2026 Reignance Studios. MIT License, see LICENSE.

#include "RSAsyncWatchAttribute.h"

#include "AbilitySystemComponent.h"
#include "RSAbilitySystemLibrary.h"

URSAsyncWatchAttribute* URSAsyncWatchAttribute::WatchAttributes(AActor* Actor, const TArray<FGameplayAttribute>& Attributes, bool bFireInitialValue)
{
	URSAsyncWatchAttribute* Action = NewObject<URSAsyncWatchAttribute>();
	Action->WeakASC = URSAbilitySystemLibrary::FindAbilitySystemComponent(Actor);
	for (const FGameplayAttribute& Attribute : Attributes)
	{
		// A duplicate would bind twice and fire OnChanged twice per change.
		Action->Watched.AddUnique(Attribute);
	}
	Action->bFireInitial = bFireInitialValue;
	Action->RegisterWithGameInstance(Actor);
	return Action;
}

void URSAsyncWatchAttribute::Activate()
{
	UAbilitySystemComponent* ASC = WeakASC.Get();
	if (!ASC)
	{
		// Common on clients: the PlayerState (and its ASC) has not replicated yet.
		// Retry from OnRep_PlayerState instead of polling.
		Cancel();
		return;
	}

	for (const FGameplayAttribute& Attribute : Watched)
	{
		if (!Attribute.IsValid())
		{
			continue;
		}

		Bindings.Emplace(Attribute, ASC->GetGameplayAttributeValueChangeDelegate(Attribute).AddUObject(this, &URSAsyncWatchAttribute::HandleChange));

		if (bFireInitial)
		{
			const float Value = ASC->GetNumericAttribute(Attribute);
			OnChanged.Broadcast(Attribute, Value, Value);
		}
	}
}

void URSAsyncWatchAttribute::HandleChange(const FOnAttributeChangeData& Data)
{
	OnChanged.Broadcast(Data.Attribute, Data.NewValue, Data.OldValue);
}

void URSAsyncWatchAttribute::Cancel()
{
	if (UAbilitySystemComponent* ASC = WeakASC.Get())
	{
		for (const TPair<FGameplayAttribute, FDelegateHandle>& Binding : Bindings)
		{
			ASC->GetGameplayAttributeValueChangeDelegate(Binding.Key).Remove(Binding.Value);
		}
	}
	Bindings.Reset();
	Super::Cancel();
}