using Sandbox;
using System;

namespace VeloX.Powertrain;

public abstract class PowertrainComponent : Component
{

	protected override void OnAwake()
	{
		Vehicle ??= Components.Get<VeloXBase>( FindMode.EverythingInSelfAndAncestors );
	}

	public const float RAD_TO_RPM = 60f / MathF.Tau;
	public const float RPM_TO_RAD = 1 / (60 / MathF.Tau);
	public const float UNITS_PER_METER = 39.37f;
	public const float UNITS_TO_METERS = 0.01905f;
	public const float KG_TO_N = 9.80665f;
	public const float KG_TO_KN = 0.00980665f;

	[Property] public VeloXBase Vehicle { get; set; }
	[Property] public virtual float Inertia { get; set; } = 0.02f;


	/// <summary>
	///     Input component. Set automatically.
	/// </summary>
	[Property]
	public PowertrainComponent Input
	{
		get => _input;
		set
		{
			if ( value == null || value == this )
			{
				_input = null;
				return;
			}

			_input = value;
		}
	}

	private PowertrainComponent _input;
	public int InputNameHash;

	/// <summary>
	///     The PowertrainComponent this component will output to.
	/// </summary>
	[Property]
	public PowertrainComponent Output
	{
		get => _output;
		set
		{
			if ( value == this )
			{
				_output = null;
				return;
			}

			_output = value;
			if ( _output != null )
				_output.Input = this;
		}

	}
	private PowertrainComponent _output;

	public float RPM => angularVelocity * RAD_TO_RPM;

	protected float angularVelocity;
	protected float Torque;

	public virtual bool HasOutput => Output.IsValid();

	public virtual float QueryInertia()
	{
		if ( !HasOutput )
			return Inertia;

		return Inertia + Output.QueryInertia();
	}

	public virtual float QueryAngularVelocity( float angularVelocity )
	{
		if ( !HasOutput )
			return angularVelocity;

		return Output.QueryAngularVelocity( angularVelocity );
	}

	public virtual float ForwardStep( float torque, float inertia )
	{
		if ( !HasOutput )
			return Torque;

		return Output.ForwardStep( Torque, inertia + Inertia );
	}
}