using UnityEngine;
using System.Collections;


public delegate void ButtonDelegate(Button sender);

[ExecuteInEditMode]
public class Button : MonoBehaviour {
	public Texture2D image;
	public Texture2D mask;
	public Vector2 size;
	public Material mat;
	public Color baseColor;
	private bool pressed;
	private Rect buttonRect;
	public event ButtonDelegate EventDown;
	public event ButtonDelegate EventUp;
	public event ButtonDelegate EventClick;
	private int fingerId = -1;

	private void OnDown(){
		if (EventDown != null) {
			EventDown(this);
		}
	}

	private void OnUp(){
		if (EventUp != null) {
			EventUp(this);
		}
	}

	private void OnClick(){
		if (EventClick != null) {
			EventClick(this);
		}
	}

	public bool Pressed{
		get{return pressed; }
	}

	// Use this for initialization
	void Start () {
		EventClick += new ButtonDelegate (clickDelegate);
	}

	void clickDelegate(Button sender){
	}

	bool PointInButton(Vector2 point){
		return buttonRect.Contains(point);
	}
	
	// Update is called once per frame
	void Update () {
		buttonRect = new Rect (
			transform.position.x - size.x / 2,
			transform.position.y - size.y / 2,
			size.x, size.y);

		if (pressed) {
			Vector2 releasePoint = Vector2.zero;
			if (IsReleased (ref releasePoint)) {
				if (PointInButton (releasePoint)) {
						OnUp ();
						OnClick ();
				}
				pressed = false;
			}
		} else {
			if(IsPressing()){
				pressed = true;
				OnDown();
			}
		}
	}

	bool IsReleased(ref Vector2 point){
		#if !UNITY_WP8 || UNITY_EDITOR
		
		point = new Vector2(Input.mousePosition.x, Screen.height - Input.mousePosition.y);
		return Input.GetKeyUp (KeyCode.Mouse0);
		#else
		foreach (var t in Input.touches) {
			if(t.fingerId == fingerId){
				if((t.phase == TouchPhase.Canceled) || (t.phase == TouchPhase.Ended)){
					point = new Vector2(t.position.x, Screen.height - t.position.y);
					return true;
				}else{
					return false;
				}
			}
		}
		point = new Vector2(-1, -1);
		return true;
		#endif


	}

	bool IsPressing(){
		#if !UNITY_WP8 || UNITY_EDITOR
		if (Input.GetKeyDown (KeyCode.Mouse0)) {
			Vector2 position = new Vector2(Input.mousePosition.x, Screen.height - Input.mousePosition.y);
			return buttonRect.Contains(position);
		}
		#else
		foreach(var t in Input.touches){
			Vector2 position = new Vector2(t.position.x, Screen.height - t.position.y);
			if(buttonRect.Contains(position)){
				fingerId = t.fingerId;
				return true;
			}
		}
		#endif

		return false;
	}

	void OnGUI(){
		if (Event.current.type == EventType.Repaint) {
			mat.SetColor("_TintColor", baseColor);
			Graphics.DrawTexture (buttonRect, image, mat);
		}

	}
}