using UnityEngine;
using System.Collections;

/// <summary>
/// This component is responsible for wobbling a UI element. It will wobble smoothly using
/// perlin noise around its original position. It will also stretch and squash.
/// </summary>
public class WobbleAnim : MonoBehaviour
{

	Vector3 _originalPosition;
	float _noiseX, _noiseY;

	const float MAX_DISPLACEMENT = 20;
	const float NOISE_SPEED = 0.7f;
	const float Y_OFFSET = 100;

	public UIElementTransition elementTransition;

	bool isWobbling;

	void Awake()
	{
		if (elementTransition == null)
		{
			elementTransition = GetComponent<UIElementTransition>();
		}
		AVDebug.Assert(elementTransition != null, "WobbleAnim is assumed to be on a UI element which is transitioned. UIElementTransition component not found on "+name);
		elementTransition.OnHiding += OnHiding;
		elementTransition.OnShowComplete += OnShowComplete;
		enabled = false;
		_originalPosition = transform.localPosition;
		_noiseY = Random.value * 300; //just some random value
	}

	void OnDestroy()
	{
		if (elementTransition != null)
		{
			elementTransition.OnHiding -= OnHiding;
			elementTransition.OnShowComplete -= OnShowComplete;
		}
	}


	void Start()
	{
		iTween.ScaleTo(gameObject, iTween.Hash(
			"islocal", true,
			"time", Random.Range(0.5f, 0.8f), //make the time random so they don't look wobbling the same
			"y", 0.95f * transform.localScale.y,
			"x", 1.05f * transform.localScale.x,
			"easetype", iTween.EaseType.easeInOutSine,
			"looptype", iTween.LoopType.pingPong));
	}
	
	void Update()
	{
		if (isWobbling)
		{
			transform.localPosition = GetNextWobblyPosition();
		}
	}

	void OnHiding()
	{
		enabled = false;
		isWobbling = false;
	}

	void OnShowComplete()
	{
		enabled = true;
		//tween to the first wobbly position to avoid a glitch between original position and the first wobbly position
		iTween.ValueTo(gameObject, iTween.Hash(
			"from", 0,
			"to", 1.0f,
			"time", 0.8f,
			"easetype", iTween.EaseType.linear,
			"onupdate", "OniTweenTransitToWobbling",
			"onupdatetarget", gameObject));
	}

	Vector3 GetNextWobblyPosition()
	{
		_noiseX += NOISE_SPEED * Time.deltaTime;
		float x = Mathf.PerlinNoise(_noiseX, _noiseY) - 0.5f; //note that perlin noise is between 0 and 1... shiftin so it's between -0.5 to 0.5
		float y = Mathf.PerlinNoise(_noiseX, _noiseY + Y_OFFSET) - 0.5f;
		return _originalPosition + new Vector3(x * MAX_DISPLACEMENT, y * MAX_DISPLACEMENT);
	}

	void OniTweenTransitToWobbling(float f)
	{
		if (f == 1)
		{
			isWobbling = true;
		} else
		{
			transform.localPosition = transform.localPosition * (1-f) + GetNextWobblyPosition() * f;
		}
	}
}