#pragma once

#include "CoreMinimal.h"

class UDescentTerrainSubsystem;

/** Constants of the helm (DESIGN_UE.md section 3.6; requirements U4, U9, V12). */
namespace Descent::Tune::Helm
{
	constexpr double TopSpeedMps = 2.0;             // U9: kept
	constexpr double SpeedTau = 1.2;                // U9: 90 % of top speed 2.8 s after the lever is full (v2: about 20 s)
	constexpr double LeverPerSec = 1.5;
	constexpr double ThrottleMin = -0.5, ThrottleMax = 1.0;
	constexpr double LateralMps = 0.6, LateralTau = 1.5;
	constexpr double BallastMps = 1.3, BallastTau = 1.5;
	constexpr double AimYawDegPerPixel = 0.05, AimPitchDegPerPixel = 0.03;   // U4: the mouse moves the aim point
	constexpr double AimYawLimitDeg = 40.0, AimPitchLimitDeg = 10.0;
	constexpr double YawGain = 1.2, YawRateMax = 0.10, YawTau = 0.8, YawAccelBase = 0.03, YawAccelPerMps = 0.01;   // rad, s
	constexpr double PitchTau = 2.5, PitchMinSpeed = 0.3;
	constexpr double RollPerYawRate = -0.25;
	constexpr double ContactBand = 0.5, PushScale = 0.6, PushPerContact = 0.35, NormalRemove = 0.9, YawTorque = 0.00006, ContactDrag = 1.5;
	constexpr double DamageBase = 0.08, DamagePerMps = 0.9;
	constexpr double PowerDrainPerThrottle = 0.05, PowerRegen = 0.02;
	constexpr double RatingM = 3250.0;
	constexpr double CrippledThrottle = 0.25, CrippledBallast = 0.4;
	constexpr double ProximityRangeM = 30.0, ProximityHz = 4.0;
	constexpr double WaypointReachM = 14.0, StallAfterSec = 40.0;
	constexpr int32 NumViews = 5;
}

/** The carrier under the helm, as plain data: the automation tests fly it without an actor. Metres, degrees; yaw rate in rad/s. */
struct THEDESCENT_API FCarrierHelmState
{
	FVector PosM = FVector::ZeroVector;
	double YawDeg = 0.0, PitchDeg = 0.0;
	double VFwd = 0.0, VLat = 0.0, VBal = 0.0;
	double YawRate = 0.0;
	// commands
	double Throttle = 0.0;           // the lever, -0.5 .. 1
	double AimYawDeg = 0.0, AimPitchDeg = 0.0;
	double Ballast = 0.0, Strafe = 0.0;   // -1 .. 1
	// consequences
	double Hull = 100.0, Power = 100.0;
	int32 Contacts = 0;
	double Scrape = 0.0, SumPen = 0.0;

	FVector VelocityMps() const;
	bool IsCrippled() const { return Hull <= 0.0; }
	bool IsAtRest() const;
	/** Leaving the helm: every target to zero, the aim on the hull. */
	void AllStop();
	/** The mouse: moves the aim, kept within 40 degrees of the heading and 10 degrees of level. */
	void AddAim(double DeltaYawDeg, double DeltaPitchDeg);
	/** One step of section 3.6 against the density field (null terrain: open water). */
	void Step(double Dt, UDescentTerrainSubsystem* Terrain);
};

/** Follows a carrier route of section 2.10 waypoint by waypoint through the same helm commands a player has. */
struct THEDESCENT_API FCarrierAutopilot
{
	bool bOn = false;
	int32 Route = 0;                 // 0 .. 2
	int32 Index = 0;
	bool bStalled = false, bDone = false;
	double LineUpSec = 0.0;   // time spent lining up over a well before the descent
	double StallTimer = 0.0, BestDist = 1e9;

	void Start(int32 InRoute);
	void Stop() { bOn = false; }
	void Step(FCarrierHelmState& Helm, double Dt);
};