// Georgy Treshchev 2025.

#pragma once

#include "CoreMinimal.h"
#include "RealisticMetaHumanLipSyncGenerator.h"
#include "Animation/AnimNodeBase.h"
#include "BlendRealisticMetaHumanLipSyncAnimNode.generated.h"

USTRUCT(BlueprintType)
struct RUNTIMEMETAHUMANLIPSYNC_API FAnimNode_BlendRealisticMetaHumanLipSync : public FAnimNode_Base
{
    GENERATED_BODY()

public:
    FAnimNode_BlendRealisticMetaHumanLipSync();
    
    // FAnimNode_Base interface
    virtual void Initialize_AnyThread(const FAnimationInitializeContext& Context) override;
    virtual void CacheBones_AnyThread(const FAnimationCacheBonesContext& Context) override;
    virtual void Update_AnyThread(const FAnimationUpdateContext& Context) override;
    virtual void Evaluate_AnyThread(FPoseContext& Output) override;
    virtual void GatherDebugData(FNodeDebugData& DebugData) override;
    // End of FAnimNode_Base interface

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

    UPROPERTY(EditAnywhere, BlueprintReadWrite, transient, Category=Copy, meta=(PinShownByDefault))
    TWeakObjectPtr<URealisticMetaHumanLipSyncGenerator> LipSyncGenerator;

    /** Controls how quickly facial expressions transition during active speech. Higher values result in faster, more abrupt transitions */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings, meta=(ClampMin="0.1", ClampMax="100.0"))
    float InterpolationSpeed = 30.0f;

    /** Controls how quickly facial expressions transition back to idle/neutral state. Lower values create smoother, more gradual returns to rest pose */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings, meta=(ClampMin="0.1", ClampMax="100.0"))
    float IdleInterpolationSpeed = 15.0f;

    /** Duration in seconds after which lip sync resets to idle state. Useful to prevent expressions from continuing after audio stops */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings)
    float ResetTime = 0.2f;

    /** When enabled, preserves the last emotional state during idle periods instead of resetting to neutral */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings)
    bool bPreserveIdleState = false;

    /** Controls which facial regions are preserved during idle state. Only effective when bPreserveIdleState is true */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings, meta=(EditCondition="bPreserveIdleState"))
    bool bPreserveEyeExpressions = true;

    /** Controls which facial regions are preserved during idle state. Only effective when bPreserveIdleState is true */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings, meta=(EditCondition="bPreserveIdleState"))
    bool bPreserveBrowExpressions = true;

    /** Controls which facial regions are preserved during idle state. Only effective when bPreserveIdleState is true */
    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Settings, meta=(EditCondition="bPreserveIdleState"))
    bool bPreserveMouthShape = false;

private:
    /** Current control values for smooth interpolation */
    TMap<FString, float> CurrentControlValues;
    
    /** Target control values from the lip sync generator */
    TMap<FString, float> TargetControlValues;

    /** Preserved idle state values */
    TMap<FString, float> IdleStateValues;
    
    /** Time since the last control values change */
    float TimeSinceLastChange = 0.0f;

    /** Helper function to determine if a control should be preserved during idle */
    bool ShouldPreserveControl(const FString& ControlName) const;

    /** Helper function to update idle state preservation */
    void UpdateIdleStatePreservation();
};