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

#include "Capture/DisplayClusterMediaCaptureNodeFull.h"

#include "DisplayClusterMediaLog.h"

#include "RenderGraphBuilder.h"
#include "RenderGraphUtils.h"
#include "RHICommandList.h"
#include "RHIResources.h"
#include "UnrealClient.h"

#include "Engine/Engine.h"
#include "Engine/GameViewportClient.h"


FDisplayClusterMediaCaptureNodeFull::FDisplayClusterMediaCaptureNodeFull(
	const FString& InMediaId,
	const FString& InClusterNodeId,
	UMediaOutput* InMediaOutput,
	UDisplayClusterMediaOutputSynchronizationPolicy* SyncPolicy
)
	: FDisplayClusterMediaCaptureNodeBase(InMediaId, InClusterNodeId, InMediaOutput, SyncPolicy)
{
}

FIntPoint FDisplayClusterMediaCaptureNodeFull::GetCaptureSize() const
{
	// Return backbuffer runtime size
	if (GEngine && GEngine->GameViewport && GEngine->GameViewport->Viewport)
	{
		const FIntPoint Size = GEngine->GameViewport->Viewport->GetSizeXY();

		UE_LOG(LogDisplayClusterMedia, Log, TEXT("'%s' capture size is [%d, %d]"), *GetMediaId(), Size.X, Size.Y);

		return Size;
	}

	UE_LOG(LogDisplayClusterMedia, Warning, TEXT("'%s' couldn't get viewport size"), *GetMediaId());

	return FIntPoint();
}

void FDisplayClusterMediaCaptureNodeFull::ProcessPostBackbufferUpdated_RenderThread(FRHICommandListImmediate& RHICmdList, FViewport* Viewport)
{
	if (!Viewport)
	{
		UE_LOG(LogDisplayClusterMedia, Warning, TEXT("'%s' capture failed, got invalid viewport"), *GetMediaId());
		return;
	}

	if (FRHITexture* const BackbufferTexture = Viewport->GetRenderTargetTexture())
	{
		FRDGBuilder GraphBuilder(RHICmdList);

		// Prepare capture request data
		FRDGTextureRef BackbufferTextureRef = RegisterExternalTexture(GraphBuilder, BackbufferTexture, TEXT("DCMediaOutBackbufferTex"));
		const FIntRect TextureRegion = { FIntPoint::ZeroValue, BackbufferTextureRef->Desc.Extent };
		const FMediaOutputTextureInfo TextureInfo{ BackbufferTextureRef, TextureRegion };

		UE_LOG(LogDisplayClusterMedia, VeryVerbose, TEXT("'%s' capturing backbuffer of size %dx%d"),
			*GetMediaId(), BackbufferTextureRef->Desc.Extent.X, BackbufferTextureRef->Desc.Extent.Y);

		// Capture backbuffer
		ExportMediaData_RenderThread(GraphBuilder, TextureInfo);

		GraphBuilder.Execute();
	}
}