FName UStructuralDamageEffectComponent::ParameterName = TEXT("Damage");

UStructuralDamageEffectComponent::UStructuralDamageEffectComponent()
{
    DamageMask = CreateDefaultSubobject<UTextureRenderTarget2D>(TEXT("DamageMask"));
    DamageMask->RenderTargetFormat = ETextureRenderTargetFormat::RTF_R8;
}

void UStructuralDamageEffectComponent::Initialize(UMaterialCopyComponent* InMaterialCopy, int32 InDamageMaskResolution)
{
    DamageMask->InitAutoFormat(InDamageMaskResolution, InDamageMaskResolution);
    DamageMask->UpdateResourceImmediate(true);

    float Value = 0.0f;
    if (InMaterialCopy->MaterialInstances.Num() > 0)
        for (auto i = 0; i < InMaterialCopy->MaterialInstances.Num(); i++)
        {
            if (InMaterialCopy->MaterialInstances[i]->GetScalarParameterValue(ParameterName, Value))
                Materials.Add(InMaterialCopy->MaterialInstances[i]);
        }
}

void UStructuralDamageEffectComponent::SetDamage(float InValue)
{
    InValue = FMath::Clamp(InValue, 0.0f, 1.0f);

    if (Materials.Num() > 0)
        for (auto i = 0; i < Materials.Num(); i++)
            Materials[i]->SetScalarParameterValue(ParameterName, InValue);
}

void UStructuralDamageEffectComponent::AddHit(FVector InLocation, FVector InDirection, float InRadius)
{
    // TODO: This material is null here- what!!?
    DamageMaskMaterial->SetVectorParameterValue(TEXT("Location"), InLocation);
    DamageMaskMaterial->SetVectorParameterValue(TEXT("Direction"), InDirection);
    DamageMaskMaterial->SetScalarParameterValue(TEXT("Radius"), InRadius);

    UKismetRenderingLibrary::DrawMaterialToRenderTarget(this, DamageMask, DamageMaskMaterial);

    DamageMask->UpdateResource();
}

void UStructuralDamageEffectComponent::BeginPlay()
{
    Super::BeginPlay();

    if (DamageMask->Resource != nullptr)
    {
        if (Materials.Num() > 0)
        {
            UMaterialInterface* OriginalMaterial = LoadObject<UMaterialInterface>(nullptr, TEXT("Material'/Game/Empires/Materials/M_DamageMaskCreator.M_DamageMaskCreator'"));
            DamageMaskMaterial = UMaterialInstanceDynamic::Create(OriginalMaterial, GetOuter());

            for (auto i = 0; i < Materials.Num(); i++)
                Materials[i]->SetTextureParameterValue(TEXT("DamageMask"), DamageMask);
        }
    }
}