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

#pragma once

#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "Animation/AnimNodeBase.h"
#include "AnimNode_ModifyCurve.generated.h"

UENUM()
enum class EModifyCurveApplyMode : uint8
{
	/** Add new value to input curve value */
	Add,

	/** Scale input value by new value */
	Scale,

	/** Blend input with new curve value, using Alpha setting on the node */
	Blend,

	/** Blend the new curve value with the last curve value using Alpha to determine the weighting (.5 is a moving average, higher values react to new values faster, lower slower) */
	WeightedMovingAverage,

	/** Remaps the new curve value between the CurveValues entry and 1.0 (.5 in CurveValues makes 0.51 map to 0.02) */
	RemapCurve
};

/** Easy way to modify curve values on a pose */
USTRUCT(BlueprintInternalUseOnly)
struct ANIMGRAPHRUNTIME_API FAnimNode_ModifyCurve : public FAnimNode_Base
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere, EditFixedSize, BlueprintReadWrite, Category = Links)
	FPoseLink SourcePose;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, editfixedsize, Category = ModifyCurve, meta = (PinHiddenByDefault))
	TMap<FName, float> CurveMap;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, editfixedsize, Category = ModifyCurve, meta = (PinShownByDefault))
	TArray<float> CurveValues;

	UPROPERTY()
	TArray<FName> CurveNames;

	TArray<float> LastCurveValues;
	TMap<FName, float> LastCurveMapValues;
	bool bInitializeLastValuesMap;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = ModifyCurve, meta = (PinShownByDefault))
	float Alpha;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = ModifyCurve)
	EModifyCurveApplyMode ApplyMode;

	FAnimNode_ModifyCurve();

	// FAnimNode_Base interface
	virtual void Initialize_AnyThread(const FAnimationInitializeContext& Context) override;
	virtual void CacheBones_AnyThread(const FAnimationCacheBonesContext& Context) override;
	virtual void Evaluate_AnyThread(FPoseContext& Output) override;

	virtual void Update_AnyThread(const FAnimationUpdateContext& Context) override;
	// End of FAnimNode_Base interface

#if WITH_EDITOR
	/** Add new curve being modified */
	void AddCurve(const FName& InName, float InValue);
	/** Remove a curve from being modified */
	void RemoveCurve(int32 PoseIndex);
#endif // WITH_EDITOR

private:
	void ProcessCurveOperation(const EModifyCurveApplyMode& InApplyMode, FPoseContext& Output, const SmartName::UID_Type& NameUID, float CurrentValue, float NewValue);
	void ProcessCurveWMAOperation(FPoseContext& Output, const SmartName::UID_Type& NameUID, float CurrentValue, float NewValue, float& InOutLastValue);
};