using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class Dust : MonoBehaviour {

	public Animator animator;

	private float direction;
	private float dirSpeed;
	private float speed;
	private float speedAcc;

	private float duration;
	private float startTime;
	private bool isHiding;

	public void Show()
	{
		gameObject.SetActive(true);
		animator.Play("DustShow", 0, 0);
		direction = Random.Range(0, 2f*Mathf.PI);
		duration = Random.Range(5f, 10f);
		startTime = GameTime.time;
		isHiding = false;
		Rotate();
	}

	public void Hide()
	{
		isHiding = true;
		animator.Play("DustHide", 0, 0);
	}

	public void Remove()
	{
		gameObject.SetActive(false);
		if(!cacheList.Contains(this))
			cacheList.Add(this);
	}

	// Update is called once per frame
	void Update () 
	{
		Vector3 pos = transform.position;
		pos.x += Mathf.Cos(direction) * speed * GameTime.deltaTime;
		pos.z += Mathf.Sin(direction) * speed * GameTime.deltaTime;
		transform.position = pos;

		direction += dirSpeed*GameTime.deltaTime;
		speed += 0.01f*GameTime.deltaTime;
		speed = NumberUtil.forceBetween(speed, 0.5f, 3f);

		if(Random.Range(0, 100) < 5)
			speed += Random.Range(-0.5f, 0.5f);
		if(Random.Range(0, 100) < 5)
			dirSpeed = Random.Range(-2f, 2f);
		Rotate();

		if(!isHiding && GameTime.time - startTime > duration)
			Hide();
	}

	private void Rotate()
	{
		Vector3 angle = transform.eulerAngles;
		angle.y = -NumberUtil.radianToAngle(direction);
		transform.eulerAngles = angle;
	}


	private static List<Dust> cacheList = new List<Dust>();
	public static Dust CreateDust(GameObject prefab)
	{
		Dust dust = null;
		if(cacheList.Count > 0)
		{
			dust = cacheList[0];
			cacheList.RemoveAt(0);
		}
		else
		{
			GameObject obj = Instantiate<GameObject>(prefab);
			DontDestroyOnLoad(obj);
			dust = obj.GetComponent<Dust>();
		}
		return dust;
	}
}