using UnityEngine;
using System.Collections;

public class AsteroidController : MonoBehaviour {

    private Transform player;
    private Rigidbody rigidBody;
    private const int speed = 500;
    public float distanceFromPlayer;
    public float distanceFromTarget;
    private bool reachedTarget = false;
    public int trackingAccuracy = 10;

    public float movementSpeed;

    [HideInInspector]
    private Vector3 targetedPosition;

    // Use this for initialization
    void Start () {
        player = GameObject.FindGameObjectWithTag("Player").GetComponent<Transform>();
        rigidBody = GetComponent<Rigidbody>();
        CalculateTargetLocation();
    }

    // Update is called once per frame
    void Update ()
    {
        distanceFromPlayer = Mathf.Abs(Vector3.Distance(player.position, transform.position));
        if (distanceFromPlayer > AsteroidSpawner.maxDistance)
        {
            CalculateTargetLocation();
            reachedTarget = false;
        }

        distanceFromTarget = Mathf.Abs(Vector3.Distance(targetedPosition, transform.position));
        if (distanceFromTarget < 5f)
        {
            reachedTarget = true;
        }
        rigidBody.velocity = Vector3.ClampMagnitude(rigidBody.velocity, speed);
    }

    void FixedUpdate () {
        if (!reachedTarget)
        {
            Vector3 directionalForce = targetedPosition * speed;
            rigidBody.AddForce(directionalForce);
        }
    }

    void CalculateTargetLocation()
    {
        // calculate a random position around the player
        float angle = Random.Range(0.0f, Mathf.PI * 2);
        Vector3 circle = new Vector3(Mathf.Sin(angle), 0, Mathf.Cos(angle));
        circle *= trackingAccuracy;
        circle += player.position;

        targetedPosition = circle;
    }
}