using Machines.Events;

namespace Machines.Player;

/// <summary>
/// Animates wheel steering and spin; finds bones by name from CarResource
/// </summary>
public sealed class CarWheelVisuals : Component, ICarChangeListener
{
	[RequireComponent]
	public Car Car { get; private set; }

	/// <summary>
	/// Maximum visual steer angle for the front wheels (degrees).
	/// </summary>
	[Property, Group( "Steering" )]
	public float MaxSteerAngle { get; set; } = 35f;

	/// <summary>
	/// How quickly the front wheels turn to the target steer angle.
	/// </summary>
	[Property, Group( "Steering" )]
	public float SteerSpeed { get; set; } = 15f;

	/// <summary>
	/// Wheel radius in units, used to compute spin rate from speed
	/// </summary>
	[Property, Group( "Spin" )]
	public float WheelRadius { get; set; } = 10f;

	private CarMovement _movement;
	private GameObject _wheelFL;
	private GameObject _wheelFR;
	private GameObject _wheelBL;
	private GameObject _wheelBR;
	private float _currentSteerAngle;
	private float _spinAngle;

	protected override void OnStart()
	{
		_movement = GetComponent<CarMovement>();
		ResolveWheels();
	}

	void ICarChangeListener.OnCarChanged( Car car )
	{
		ResolveWheels();
	}

	private void ResolveWheels()
	{
		if ( !Car.IsValid() )
			return;

		var resource = Car.Resource;
		if ( !resource.IsValid() || !Car.Renderer.IsValid() )
		{
			return;
		}

		_wheelFL = ResolveBone( resource.WheelFLBone );
		_wheelFR = ResolveBone( resource.WheelFRBone );
		_wheelBL = ResolveBone( resource.WheelBLBone );
		_wheelBR = ResolveBone( resource.WheelBRBone );
	}

	private GameObject ResolveBone( string name )
	{
		var boneObject = Car.Renderer.GetBoneObject( name );
		boneObject?.Flags |= GameObjectFlags.ProceduralBone;

		return boneObject;
	}

	protected override void OnUpdate()
	{
		if ( !_movement.IsValid() )
			return;

		var dt = Time.Delta;
		if ( dt <= 0f )
			return;

		UpdateSteering( dt );
		UpdateSpin( dt );
	}

	private void UpdateSteering( float dt )
	{
		var targetAngle = _movement.TurnInput * MaxSteerAngle;
		_currentSteerAngle = MoveToward( _currentSteerAngle, targetAngle, SteerSpeed * MaxSteerAngle * dt );
	}

	private void UpdateSpin( float dt )
	{
		if ( WheelRadius <= 0f )
			return;

		var angularSpeed = _movement.CurrentSpeed / WheelRadius * (180f / MathF.PI);
		_spinAngle += angularSpeed * dt;
		_spinAngle %= 360f;

		// Apply combined rotation to all wheels
		ApplyWheelRotation( _wheelFL, _currentSteerAngle );
		ApplyWheelRotation( _wheelFR, _currentSteerAngle );
		ApplyWheelRotation( _wheelBL, 0f );
		ApplyWheelRotation( _wheelBR, 0f );
	}

	private void ApplyWheelRotation( GameObject wheel, float steerYaw )
	{
		if ( !wheel.IsValid() )
			return;

		wheel.LocalRotation = Rotation.From( _spinAngle, steerYaw, 0f );
	}

	private static float MoveToward( float current, float target, float maxDelta )
	{
		if ( MathF.Abs( target - current ) <= maxDelta )
			return target;
		return current + MathF.Sign( target - current ) * maxDelta;
	}
}