using UnityEngine;

[RequireComponent(typeof(Rigidbody))]
public class MegaShapeRBodyPathNew : MonoBehaviour
{
	public MegaShape	path;					// The Shape that will attract the rigid body
	public int			curve		= 0;		// The sub curve of that shape usually 0
	public bool			usealpha	= false;	// Set to true to use alpha value instead of finding the nearest point on the curve.
	public float		impulse		= 10.0f;	// The force that will applied if the rbody is 1 unit away from the curve
	public float		inputfrc	= 10.0f;	// Max forcce for user input
	public bool			align		= true;		// Should rigid body align to the spline direction
	public float		alpha		= 0.0f;		// current position on spline, The alpha value to use is usealpha mode set, allows you to set the point on the curve to attract the rbody (0 - 1)
	public float		delay		= 1.0f;		// how quickly user input gets to max force
	public float		drag		= 0.0f;		// slows object down when moving
	public float		jump		= 10.0f;	// Jump force to apply when space is pressed
	public float		breakforce	= 100.0f;	// force above which the rigidbody will break free from the path
	public bool			connected	= true;		// Controls whether the object is connected to spline or not
	Rigidbody			rb;
	float				drive		= 0.0f;
	float				vel			= 0.0f;
	float				tfrc		= 0.0f;
	Vector3				nps;

	void Start()
	{
		rb = GetComponent<Rigidbody>();

		for ( int i = 0; i < 4; i++ )
			Position();
	}

	void Update()
	{
		tfrc = 0.0f;
		if ( Input.GetKey(KeyCode.UpArrow) )
			tfrc = -inputfrc;
		else
		{
			if ( Input.GetKey(KeyCode.DownArrow) )
				tfrc = inputfrc;
		}

		if ( Input.GetKeyDown(KeyCode.Space) )
			rb.AddForce(Vector3.up * jump);

		drive = Mathf.SmoothDamp(drive, tfrc, ref vel, delay);

		Debug.DrawLine(transform.position, nps);
	}


	// Position object on spline
	public void Position()
	{
		if ( path && rb && connected )
		{
			Vector3 p = rb.position;	//transform.position;

			Vector3 tangent = Vector3.zero;
			int kn = 0;

			Vector3 np = Vector3.zero;
			if ( usealpha )
				np = path.transform.TransformPoint(path.InterpCurve3D(curve, alpha, true));
			else
				np = path.FindNearestPointWorldXZ(p, 15, ref kn, ref tangent, ref alpha);

			nps = np;
			np.y = p.y;
			Vector3 dir = np - p;
			dir.y = 0.0f;

			Vector3 iforce = dir * impulse;

			rb.AddForce(iforce, ForceMode.Impulse);

			np.y = p.y;
			rb.MovePosition(np);
			transform.position = np;

			Vector3 p1 = path.transform.TransformPoint(path.InterpCurve3D(curve, alpha + 0.0001f, true));
			p1.y = p.y;

			if ( align )
			{
				Vector3 ndir = (p1 - np).normalized;
				Vector3 rdir = transform.forward;
				rdir.y = 0.0f;
				rdir = rdir.normalized;

				float angle = Vector3.Angle(rdir, ndir);

				Vector3 cross = Vector3.Cross(rdir, ndir);

				if ( cross.y < 0.0f )
					angle = -angle;

				Quaternion qrot = rb.rotation;
				Quaternion yrot = Quaternion.Euler(new Vector3(0.0f, angle, 0.0f));	//LookRotation(p1 - np);	//.eulerAngles;

				rb.MoveRotation(qrot * yrot);
			}
		}
	}

	void FixedUpdate()
	{
		if ( path && rb && connected )
		{
			Vector3 p = rb.position;	//transform.position;

			Vector3 tangent = Vector3.zero;
			int kn = 0;

			Vector3 np = Vector3.zero;
			if ( usealpha )
				np = path.transform.TransformPoint(path.InterpCurve3D(curve, alpha, true));
			else
				np = path.FindNearestPointWorldXZ(p, 15, ref kn, ref tangent, ref alpha);

			nps = np;
			np.y = p.y;
			Vector3 dir = np - p;
			dir.y = 0.0f;

			Vector3 iforce = dir * impulse;

			float mag = iforce.magnitude / Time.fixedDeltaTime;
			if ( mag > breakforce )
			{
				connected = false;
				rb.angularVelocity = Vector3.zero;
			}

			if ( connected )
			{
				rb.AddForce(iforce, ForceMode.Impulse);

				np.y = p.y;
				rb.MovePosition(np);

				Vector3 p1 = path.transform.TransformPoint(path.InterpCurve3D(curve, alpha + 0.0001f, true));
				p1.y = p.y;

				if ( align )
				{
					Vector3 ndir = (p1 - np).normalized;
					Vector3 rdir = transform.forward;
					rdir.y = 0.0f;
					rdir = rdir.normalized;

					float angle = Vector3.Angle(rdir, ndir);

					Vector3 cross = Vector3.Cross(rdir, ndir);

					if ( cross.y < 0.0f )
						angle = -angle;

					Quaternion qrot = rb.rotation;
					Quaternion yrot = Quaternion.Euler(new Vector3(0.0f, angle, 0.0f));	//LookRotation(p1 - np);	//.eulerAngles;

					rb.MoveRotation(qrot * yrot);
				}

				if ( drag != 0.0f )
					rb.AddForce(-rb.velocity * drag);

				if ( drive != 0.0f )
					rb.AddForce((np - p1).normalized * drive, ForceMode.Force);
			}
		}
	}
}