#include "CoreMinimal.h"
// #include "Kismet/KismetSystemLibrary.h"
// #include "CommonTypes.h"
// #include "Kismet/BlueprintFunctionLibrary.h"

#include "ScriptedAnimation.generated.h"

class UEnhancedInputLocalPlayerSubsystem;
class UAnimSequenceBase;


USTRUCT(BlueprintType)
struct INTEGRATION_API FlxScriptedAnimation
{
    GENERATED_BODY()

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
	UAnimSequenceBase *Sequence = nullptr;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, AdvancedDisplay)
	int64 AqHash = 0;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, AdvancedDisplay)
	double FadeInDuration = 0.0;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, AdvancedDisplay)
	double FadeOutDuration = 0.0;
	
    // StartTime and EndTime.
    // 
    // StartTime is the world time when the animation was actually started.
    // That is immutable once the animation is created.  However, EndTime is
    // mutable: initially, it is set to StartTime + Animation.Length.  But
    // script requests that the animation be truncated, the EndTime
    // may be reduced to implement the truncation.
    //

	UPROPERTY(EditAnywhere, BlueprintReadWrite, AdvancedDisplay)
    double StartTime = 0.0;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, AdvancedDisplay)
    double EndTime = 0.0;

    // Calculate the progress of a fade.
    //
    static double CalculateFade(double Offset, double Fade);

    // Calculate Elapsed Time (unclamped)
    //
    // If current time is before the animation's start time, then
    // elapsed time will be negative.
    //
    double UnclampedElapsedTime(double CurrentTime) const;

    // Calculate Time Left (unclamped)
    // 
    // If current time is after the animation's end time, then
    // time left will be negative.
    //
    double UnclampedTimeLeft(double CurrentTime) const;

    // Calculate Elapsed Time (clamped)
    //
    // If current time is before the animation's start time, then
    // elapsed time will be zero.
    //
    double ClampedElapsedTime(double CurrentTime) const;

    // Calculate Time Left (clamped)
    // 
    // If current time is after the animation's end time, then
    // time left will be zero.
    //
    double ClampedTimeLeft(double CurrentTime) const;

    // Calculate the progress of the fadein.
    //
    double CalcFadeInAlpha(double CurrentTime) const;
    
    // Calculate the progress of the fadeout.
    //
    double CalcFadeOutAlpha(double CurrentTime) const;
    
    // Calculate the combined alpha of the fade-in-out.
    //
    double CalcFadeInOutAlpha(double CurrentTime) const;

    // Cause an animation to start fading right away.
    //
    // Sets up the animation to start fading immediately, by adjusting
    // the animation's EndTime.  If the FadeOut time of the animation
    // is longer than the allowed fade, that will be reduced.
    // If the animation was already in the process of fading in
    // or fading out, then that will be taken into account.
    //
    // If you want to chop an animation off abruptly, without any fade,
    // simply set AllowedFade to 0.0.
    //
    void InitiateFadeOut(double CurrentTime, double AllowedFade);
};


UCLASS(BlueprintType)
class INTEGRATION_API UlxScriptedAnimations : public UObject
{
	GENERATED_BODY()

private:
	UPROPERTY()
	int KeepCount = 3;

	UPROPERTY()
	TArray<FlxScriptedAnimation> Animations;

	// If the number of elements in the array exceeds the count, discard.
	//
	void Keep(int n);
	
public:
	// Allow read-only access anywhere.
	//
	const TArray<FlxScriptedAnimation> &GetAnimations() const { return Animations; }

	// Add a scripted animation.
	//
	// The step is inserted at the front of the array: the first animation
	// in the array is always the most recent.  All other steps are shifted
	// back.  If the array size exceeds the KeepCount, it is truncated.
	//
	// The Aq Hash parameter can be used to associate a scripted animation
	// with a step in the animation queue.  This makes it feasible to garbage
	// collect the scripted animation if the animation queue step disappears.
	//
	UFUNCTION(BlueprintCallable, Category = "Luprex|Scripted Animations", meta=(WorldContext = "WorldContextObject"))
	void AddAnimation(
		UObject *WorldContextObject, UAnimSequenceBase* Sequence, double FadeInTime = 0.2, double FadeOutTime = 0.2, int64 AqHash=0);

	// Fade animations whose corresponding animation queue step is dead.
	//
	// Sometimes, predictive reexecution causes an animation step to
	// vanish from the animation queue.  When that happens, it is usually
	// desirable to terminate any scripted animations that were launched
	// by that animation step.  You don't want to cut them off abruptly,
	// you want to fade them out.  This function causes all animations that
	// are owned by a dead animation step to begin fading.
	//
	UFUNCTION(BlueprintCallable, Category = "Luprex|Scripted Animations", meta=(WorldContext = "WorldContextObject"))
	void FadeGarbage(TArray<int32> Hashes, double CurrentTime);
};

UCLASS()
class INTEGRATION_API UlxScriptedAnimationLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

private:


public:
	// Get the data to drive Sequence Evaluators and Multi Blend
	//
	// To apply scripted animations in an Anim Graph, you will need
	// three sequence evaluators and a multi-blend node.  This
	// function outputs the input parameters for all of those nodes.
	//
    UFUNCTION(BlueprintPure, Category = "Luprex|Scripted Animations", meta=(BlueprintThreadSafe))
	static void ScriptedAnimationEvaluatorData(const UlxScriptedAnimations *Animations, double CurrentTime,
		UAnimSequenceBase *&Sequence0, float &ExplicitTime0,
		UAnimSequenceBase *&Sequence1, float &ExplicitTime1,
		UAnimSequenceBase *&Sequence2, float &ExplicitTime2,
		float &BaseAlpha, float &Sequence0Alpha, float &Sequence1Alpha, float &Sequence2Alpha);

};