#pragma once

#include "CoreMinimal.h"
#include "Core/DescentHandle.h"
#include "Core/DescentWorldSubsystem.h"
#include "DescentHorror.generated.h"

class UInstancedStaticMeshComponent;
class UStaticMeshComponent;

/** The horror director (M9, requirement V3; DESIGN_UE.md section 8.3). Nothing here harms the player: audio and sights only. */
namespace Descent::Horror
{
	constexpr int32 NumBeacons = 8;
	constexpr double BeaconTriggerM = 24.0, TypeCharsPerSec = 55.0;
	constexpr int32 LeviSegments = 40;
	constexpr double LeviSpacingM = 3.8, LeviSpeedMps = 8.5, LeviPathM = 520.0;
	/** dz: 0 at 1,760 m, 1 at 3,160 m. */
	THEDESCENT_API double DepthFactor(double DepthM);
	/** hallu: 0 above 25 % nutrition, 1 at 5 %. */
	THEDESCENT_API double Hallucination(double Nutrition);
	THEDESCENT_API double LeviRadiusM(int32 Segment);
}

UCLASS()
class THEDESCENT_API UDescentHorrorSubsystem : public UDescentWorldSubsystem
{
	GENERATED_BODY()

public:
	static UDescentHorrorSubsystem* Get(const UWorld* World);
	virtual void OnWorldBeginPlay(UWorld& InWorld) override;
	virtual void Deinitialize() override;

	void OnSonarPing(const FVector& OriginM, double RangeM);
	void Heartbeat();
	void StartLeviathan(bool bNear);
	void ShowPhantom();
	void StartEnding();

	int32 NumBeacons() const { return Descent::Horror::NumBeacons; }
	FVector BeaconPosM(int32 I) const;
	bool IsBeaconFound(int32 I) const { return I >= 0 && I < Descent::Horror::NumBeacons && bFound[I]; }

	bool IsLeviathanActive() const { return LeviS >= 0.0; }
	FVector LeviathanPointM(double AlongM) const;
	FVector LeviathanHeadM() const { return LeviathanPointM(LeviS); }
	double LeviathanAlongM() const { return LeviS; }

	double Dz = 0.0, Hallu = 0.0, Pulse = 0.0, EndingT = -1.0;
	int32 Heartbeats = 0, Creaks = 0, Groans = 0, Whispers = 0, Phantoms = 0, FalseRadios = 0, LogsFound = 0, Ghosts = 0, LeviPasses = 0;
	bool bEnding = false, bEndCardShown = false, bFelt = false;

	void FillWindows();

private:
	void Step(double Dt);
	void UpdateVisuals(double Dt);
	void Radio(const FString& Text, float Seconds = 7.f);

	bool bFound[Descent::Horror::NumBeacons] = { false, false, false, false, false, false, false, false };
	double CreakIn = 20.0, GroanIn = 50.0, HeartIn = 85.0, HeartEcho = -1.0, WhisperIn = 30.0, PhantomIn = 30.0, LeviIn = 0.0, PhantomLeft = 0.0, WindowTimer = 0.0, Clock = 0.0;
	// the leviathan's pass
	double LeviS = -1.0;
	FVector LeviStart = FVector::ZeroVector, LeviDir = FVector::ForwardVector;
	bool bLeviFirst = true;
	// a log being typed on the radio
	FString TypeText;
	double TypePos = -1.0;
	FRandomStream Rng{ 66666 };
	FDescentHandle StepHandle;
	UPROPERTY(Transient) TObjectPtr<AActor> Visual;
	UPROPERTY(Transient) TObjectPtr<UInstancedStaticMeshComponent> LeviBody;
	UPROPERTY(Transient) TObjectPtr<UInstancedStaticMeshComponent> LeviLights;
	UPROPERTY(Transient) TObjectPtr<UInstancedStaticMeshComponent> BeaconMesh;
	UPROPERTY(Transient) TObjectPtr<UStaticMeshComponent> Phantom;
};