// Copyright 2025 https://yuewu.dev/en  All Rights Reserved.

#pragma once

#include "BoneControllers/AnimNode_OrientationWarping.h"
#include "BoneControllers/BoneControllerTypes.h"
#include "BoneControllers/AnimNode_SkeletalControlBase.h"
#include "Settings/GMS_SettingStructLibrary.h"
#include "GMS_AnimNode_OrientationWarping.generated.h"

struct FAnimationInitializeContext;
struct FComponentSpacePoseContext;
struct FNodeDebugData;

USTRUCT(BlueprintInternalUseOnly)
struct GENERICMOVEMENTSYSTEM_API FGMS_AnimNode_OrientationWarping : public FAnimNode_SkeletalControlBase
{
	GENERATED_BODY()

	// Orientation warping evaluation mode (Graph or Manual)
	UPROPERTY(EditAnywhere,BlueprintReadWrite, Category=Evaluation, meta=(PinShownByDefault))
	EWarpingEvaluationMode Mode = EWarpingEvaluationMode::Manual;

	// The desired orientation angle (in degrees) to warp by relative to the specified RotationAxis
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinShownByDefault))
	float OrientationAngle = 0.f;

	// The character locomotion angle (in degrees) relative to the specified RotationAxis
	// This will be used in the following equation for computing the orientation angle: [Orientation = RotationBetween(RootMotionDirection, LocomotionDirection)]
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinShownByDefault))
	float LocomotionAngle = 0.f;

	// The character movement direction vector in world space
	// This will be used to compute LocomotionAngle automatically
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinShownByDefault))
	FVector LocomotionDirection = { 0.f, 0.f, 0.f };
	
	// Minimum root motion speed required to apply orientation warping
	// This is useful to prevent unnatural re-orientation when the animation has a portion with no root motion (i.e starts/stops/idles)
	// When this value is greater than 0, it's recommended to enable interpolation with RotationInterpSpeed > 0
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta = (ClampMin = "0.0", PinHiddenByDefault))
	float MinRootMotionSpeedThreshold = 10.0f;

	// Specifies an angle threshold to prevent erroneous over-rotation of the character, disabled with a value of 0
	//
	// When the effective orientation warping angle is detected to be greater than this value (default: 90 degrees) the locomotion direction will be inverted prior to warping
	// This will be used in the following equation: [Orientation = RotationBetween(RootMotionDirection, -LocomotionDirection)]
	//
	// Example: Playing a forward running animation while the motion is going backward 
	// Rather than orientation warping by 180 degrees, the system will warp by 0 degrees 
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinHiddenByDefault), meta=(ClampMin="0.0", ClampMax="180.0"))
	float LocomotionAngleDeltaThreshold = 90.f;

	// Spine bone definitions
	// Used to counter rotate the body in order to keep the character facing forward
	// The amount of counter rotation applied is driven by DistributedBoneOrientationAlpha
	// UPROPERTY(EditAnywhere, Category="Settings")  由ExternalBoneReference代替代替。
	UPROPERTY()
	TArray<FBoneReference> SpineBones;

	// IK Foot Root Bone definition
	// UPROPERTY(EditAnywhere, Category="Settings", meta=(DisplayName="IK Foot Root Bone")) 由ExternalBoneReference代替。
	UPROPERTY()
	FBoneReference IKFootRootBone;

	// IK Foot definitions
	// UPROPERTY(EditAnywhere, Category="Settings", meta=(DisplayName="IK Foot Bones")) 由ExternalBoneReference代替。
	UPROPERTY()
	TArray<FBoneReference> IKFootBones;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category= Settings, meta=(PinShownByDefault))
	FGMS_OrientationWarpingBoneReference ExternalBoneReference;

	// Rotation axis used when rotating the character body
	UPROPERTY(EditAnywhere, Category=Settings)
	TEnumAsByte<EAxis::Type> RotationAxis = EAxis::Z;

	// Specifies how much rotation is applied to the character body versus IK feet
	UPROPERTY(EditAnywhere, Category=Settings, meta=(ClampMin="0.0", ClampMax="1.0", PinHiddenByDefault))
	float DistributedBoneOrientationAlpha = 0.5f;

	// Specifies the interpolation speed (in Alpha per second) towards reaching the final warped rotation angle
	// A value of 0 will cause instantaneous rotation, while a greater value will introduce smoothing
	UPROPERTY(EditAnywhere, Category=Settings, meta=(ClampMin="0.0"))
	float RotationInterpSpeed = 10.f;

	// Max correction we're allowed to do per-second when using interpolation.
	// This minimizes pops when we have a large difference between current and target orientation.
	UPROPERTY(EditAnywhere, Category=Settings, meta=(ClampMin="0.0", EditCondition="RotationInterpSpeed > 0.0f"))
	float MaxCorrectionDegrees = 180.f;

	// Don't compensate our interpolator when the instantaneous root motion delta is higher than this. This is likely a pivot.
	UPROPERTY(EditAnywhere, Category=Settings, meta=(ClampMin="0.0", EditCondition="RotationInterpSpeed > 0.0f"))
	float MaxRootMotionDeltaToCompensateDegrees = 45.f;

	// Whether to counter compensate interpolation by the animated root motion angle change over time.
	// This helps to conserve the motion from our animation.
	// Disable this if your root motion is expected to be jittery, and you want orientation warping to smooth it out.
	UPROPERTY(EditAnywhere, Category=Settings, meta=(EditCondition="RotationInterpSpeed > 0.0f"))
	bool bCounterCompenstateInterpolationByRootMotion = true;

	UPROPERTY(EditAnywhere, Category=Experimental, meta=(PinHiddenByDefault))
	bool bScaleByGlobalBlendWeight = false;

	UPROPERTY(EditAnywhere, Category=Experimental, meta=(PinHiddenByDefault))
	bool bUseManualRootMotionVelocity = false;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Experimental, meta=(PinHiddenByDefault))
	FVector ManualRootMotionVelocity = FVector::ZeroVector;

	//RootBoneTransform is the same as CustomTransform as 
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinHiddenByDefault))
	EOrientationWarpingSpace WarpingSpace = EOrientationWarpingSpace::ComponentTransform;
	
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category=Evaluation, meta=(PinHiddenByDefault))
	FTransform WarpingSpaceTransform;

#if WITH_EDITORONLY_DATA
	// Scale all debug drawing visualization by a factor
	UPROPERTY(EditAnywhere, Category=Debug, meta=(ClampMin="0.0"))
	float DebugDrawScale = 1.f;

	// Enable/Disable orientation warping debug drawing
	UPROPERTY(EditAnywhere, Category=Debug)
	bool bEnableDebugDraw = false;
#endif

public:
	// FAnimNode_Base interface
	virtual void GatherDebugData(FNodeDebugData& DebugData) override;
	virtual void UpdateInternal(const FAnimationUpdateContext& Context) override;
	// End of FAnimNode_Base interface

	// FAnimNode_SkeletalControlBase interface
	virtual void Initialize_AnyThread(const FAnimationInitializeContext& Context) override;
	virtual void EvaluateSkeletalControl_AnyThread(FComponentSpacePoseContext& Output, TArray<FBoneTransform>& OutBoneTransforms) override;
	virtual bool IsValidToEvaluate(const USkeleton* Skeleton, const FBoneContainer& RequiredBones) override;
	// End of FAnimNode_SkeletalControlBase interface

private:
	// FAnimNode_SkeletalControlBase interface
	virtual void InitializeBoneReferences(const FBoneContainer& RequiredBones) override;
	// End of FAnimNode_SkeletalControlBase interface

	struct FOrientationWarpingSpineBoneData
	{
		FCompactPoseBoneIndex BoneIndex;
		float Weight;

		FOrientationWarpingSpineBoneData()
			: BoneIndex(INDEX_NONE)
			, Weight(0.f)
		{
		}

		FOrientationWarpingSpineBoneData(FCompactPoseBoneIndex InBoneIndex)
			: BoneIndex(InBoneIndex)
			, Weight(0.f)
		{
		}

		// Comparison Operator for Sorting
		struct FCompareBoneIndex
		{
			FORCEINLINE bool operator()(const FOrientationWarpingSpineBoneData& A, const FOrientationWarpingSpineBoneData& B) const
			{
				return A.BoneIndex < B.BoneIndex;
			}
		};
	};

	struct FOrientationWarpingFootData
	{
		TArray<FCompactPoseBoneIndex> IKFootBoneIndexArray;
		FCompactPoseBoneIndex IKFootRootBoneIndex;

		FOrientationWarpingFootData()
			: IKFootBoneIndexArray()
			, IKFootRootBoneIndex(INDEX_NONE)
		{
		}
	};

	// Computed spine bone indices and alpha weights for the specified spine definition 
	TArray<FOrientationWarpingSpineBoneData> SpineBoneDataArray;

	// Computed IK bone indices for the specified foot definitions 
	FOrientationWarpingFootData IKFootData;
	
	// Internal current frame root motion delta direction
	FVector RootMotionDeltaDirection = FVector::ZeroVector;

	// Internal orientation warping angle
	float ActualOrientationAngleRad = 0.f;
	float BlendWeight = 0.0f;

	FGraphTraversalCounter UpdateCounter;
	bool bIsFirstUpdate = false;
	void Reset(const FAnimationBaseContext& Context);

#if WITH_EDITORONLY_DATA
	// Whether we found a root motion delta attribute in the attribute stream on graph driven mode
	bool bFoundRootMotionAttribute = false;
#endif
};