using System;
using UIKit;
using CoreGraphics;

namespace Shared
{
	/// <summary>
	/// 对话框
	/// </summary>
	public class Alert
	{
		/// <summary>
		/// 当前对话框
		/// </summary>
		UIAlertView myUIAlertView;

		/// <summary>
		/// 代理
		/// </summary>
		MyUIAlertViewDelegate myUIAlertViewDelegate = new MyUIAlertViewDelegate();

		/// <summary>
		/// 对话窗
		/// </summary>
		/// <param name="title">标题</param>
		/// <param name="message">信息</param>
		/// <param name="cancelButtonText">取消按键备注，值null表示不显示取消按键</param>
		/// <param name="okButtonText">确认按键备注</param>
		public Alert(string title,string message,string cancelButtonText,string okButtonText)
		{
			myUIAlertView = new  UIAlertView ();
			myUIAlertView.Title = title;
			myUIAlertView.Message = message;
			myUIAlertView.Delegate = myUIAlertViewDelegate;
			if (cancelButtonText != null) {
				myUIAlertView.AddButton (cancelButtonText);
				myUIAlertViewDelegate.Flag = true;
			}
			myUIAlertView.AddButton (okButtonText);

			myUIAlertViewDelegate.ResultEventHandler+= (sender, e) => {
				if (ResultEventHandler != null) {
					ResultEventHandler (sender, e);
				}
			};

		}

		/// <summary>
		/// 对话窗
		/// </summary>
		/// <param name="title">标题</param>
		/// <param name="message">信息</param>
		/// <param name="okButtonText">确认按键备注</param>
		public Alert(string title,string message,string okButtonText):this(title,message,null,okButtonText)
		{
			
		}

		/// <summary>
		/// 结果通知事件，true表示选中按键，false表示取消事件
		/// </summary>
		public event EventHandler<bool> ResultEventHandler;
	
		/// <summary>
		/// 显示当前的界面
		/// </summary>
		public void Show()
		{
			myUIAlertView.Show ();
		}

		/// <summary>
		/// 对话框事件处理代理
		/// </summary>
		class MyUIAlertViewDelegate : UIAlertViewDelegate
		{
			/// <summary>
			/// 通知结果
			/// </summary>
			public event EventHandler<bool> ResultEventHandler;
			/// <summary>
			/// 是否是有取消按键
			/// </summary>
			public bool Flag;
			public override void Clicked(UIAlertView alertview, nint buttonIndex)
			{
				if (ResultEventHandler != null)
				{
					if (buttonIndex == 0)
					{
						if (Flag)
						{
							//取消按键
							ResultEventHandler(alertview, false);
						}
						else {
							//按了确定
							ResultEventHandler(alertview, true);
						}
					}
					else if (buttonIndex == 1)
					{
						//按了确定
						ResultEventHandler(alertview, true);
					}
				}
			}
		}
	}
}