using UnityEngine;
using System.Collections;
using System;

/// <summary>
/// This component is responsible for representing a screen hierarchy. It will tell all its
/// underlying UI elements to show/hide accordingly.
/// </summary>
public class ScreenBase : MonoBehaviour
{
	/// <summary>
	/// Fire when all elements have finished animating the show
	/// </summary>
	public Action OnShowComplete;
	/// <summary>
	/// Fire when all elements have finished animating the hide
	/// </summary>
	public Action OnHideComplete;

	public bool showOnStart = true;

	UIElementTransition[] _elements;

	const float MAX_TRANSITION_TIME = 0.5f;

	bool _isStarted;

	#region Unity Callbacks
	protected virtual void Awake()
	{
		bool includeInactive = true;
		_elements = GetComponentsInChildren<UIElementTransition>(includeInactive);
	}

	protected virtual IEnumerator Start()
	{
		_isStarted = true;
		//Show the menu in the next frame, otherwise the anchors wouldn't have been set up yet
		yield return null;
		if (showOnStart)
		{
			Show();
		}
	}
	#endregion

	public virtual void Show()
	{
		

		gameObject.SetActive (true);

		if (_isStarted == false)
		{
			return;
		}
		SendMessage("ShowMsg", SendMessageOptions.DontRequireReceiver); //other components might want to know about this event
		foreach (UIElementTransition e in _elements)
		{
			e.Show();
		}
		StartCoroutine(OnShowTransitionsCompleteCoroutine());
	}

	public virtual void Hide()
	{
		SendMessage("HideMsg",SendMessageOptions.DontRequireReceiver); //other components might want to know about this event
		//Debug.Log(_elements.Length);
		foreach (UIElementTransition e in _elements)
		{
			e.Hide();
		}
		if(this.gameObject.activeSelf)
		{
			StartCoroutine(OnHideTransitionsCompleteCoroutine());
		}
	}

	IEnumerator OnShowTransitionsCompleteCoroutine()
	{
		yield return new WaitForSeconds(MAX_TRANSITION_TIME);
		if (OnShowComplete != null)
		{
			OnShowComplete();
		}
	}

	IEnumerator OnHideTransitionsCompleteCoroutine()
	{
		yield return new WaitForSeconds(MAX_TRANSITION_TIME);
		if (OnHideComplete != null)
		{
			OnHideComplete();
		}
		//Stop any iTweens just in case they were not finished.
		//If we don't remove the tweens, it could cause some problems when re-enabling the screen
		//where they would continue and conflict with new tweens
		foreach (UIElementTransition e in _elements)
		{
			iTween.Stop(e.gameObject);
		}
		gameObject.SetActive(false);
	}
}