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

#pragma once

#include "MuCO/UnrealToMutableTextureConversionUtils.h"
#include "MuR/Image.h"
#include "MuR/System.h"
#include "UObject/GCObject.h"
#include "Containers/Ticker.h"
#include "Containers/Map.h"
#include "Containers/Queue.h"
#include "PixelFormat.h"
#include "Tasks/Task.h"

class UCustomizableObject;
class UTexture;
class USkeletalMesh;

/** Implementation of a mutable core provider for image parameters that are application-specific. */
class FUnrealMutableResourceProvider : public TSharedFromThis<FUnrealMutableResourceProvider>, public mu::FExternalResourceProvider, public FGCObject
{

public:
	// mu::ExternalResourceProvider interface
	// Thread: worker
	virtual TTuple<UE::Tasks::FTask, TFunction<void()>> GetImageAsync(UTexture* Texture, uint8 MipmapsToSkip, TFunction<void(TSharedPtr<mu::FImage>)>& ResultCallback) override;
	virtual TTuple<UE::Tasks::FTask, TFunction<void()>> GetReferencedImageAsync(const void* ModelPtr, int32 Id, uint8 MipmapsToSkip, TFunction<void(TSharedPtr<mu::FImage>)>& ResultCallback) override;
	virtual mu::FExtendedImageDesc GetImageDesc(UTexture* Texture) override;
	virtual TTuple<UE::Tasks::FTask, TFunction<void()>> GetMeshAsync(USkeletalMesh* SkeletalMesh, int32 LODIndex, int32 SectionIndex, TFunction<void(TSharedPtr<mu::FMesh>)>& ResultCallback) override;

#if WITH_EDITOR
	void CacheRuntimeReferencedImages(const TSharedRef<const mu::FModel>& Model, const TArray<TSoftObjectPtr<UTexture2D>>& RuntimeReferencedTextures);
#endif
	
	// Register and unregister the current CO that we are working on. This is called by internal code when building instances.
	void SetCurrentObject(const TWeakObjectPtr<UCustomizableObject>&);
	
	// FGCObject interface
	virtual void AddReferencedObjects(FReferenceCollector& Collector) override;
	virtual FString GetReferencerName() const override
	{
		return TEXT("FUnrealMutableImageProvider");
	}

private:
	/** Runtime reference to the CO being updated. It is needed for example for mesh conversion, to access to the bone id map.  */
	TWeakObjectPtr<UCustomizableObject> CurrentCustomizableObject;

	static inline const mu::FImageDesc DUMMY_IMAGE_DESC = 
			mu::FImageDesc {mu::FImageSize(32, 32), mu::EImageFormat::RGBA_UByte, 1};

	/** This will be called if an image Id has been requested by Mutable core but it has not been provided by any provider. */
	static TSharedPtr<mu::FImage> CreateDummy();
	static mu::FExtendedImageDesc CreateDummyDesc();

#if WITH_EDITOR
	struct FRuntimeReferencedImages
	{
		TWeakPtr<const mu::FModel> Model;
		TArray<TStrongObjectPtr<UTexture>> Images;
	};
	
	TMap<const void*, FRuntimeReferencedImages> RuntimeReferencedImages;
#endif

#if WITH_EDITOR
	FCriticalSection RuntimeReferencedLock;
#endif
};