package com.ll.smsbeans;

import java.util.EventObject;

/**
 *  <code>ConnectionEvent</code> 為當連接狀態（ConnectionBean，斷線、在線、連接中、連接失敗）被改變的時候，
 * 所產生的事件描述。
 *<p>
 * <code>ConnectionEvent</code> 的主要屬性為source，標記當前的事件發出者，主要用于處理有多個連接的時候。
 *
 * @author  listlike <a href="mailto:listlike@hotmail.com">
 *                      <i>&lt;listlike@hotmail.com&gt;</i></a>
 *
 */

public class ConnectionEvent extends EventObject
{
	public final static EState STATE_UNKNOWN = new EState(EState.NOT_SET);
	public final static EState STATE_DISCONNECTED =
		new EState(EState.DISCONNECTED);
	public final static EState STATE_CONNECTING = new EState(EState.CONNECTING);
	public final static EState STATE_CONNECTED = new EState(EState.CONNECTED);

	public final static EReason REASON_UNKNOWN = new EReason(EReason.NOT_SET);
	public final static EReason REASON_CLIENT_INITIATED =
		new EReason(EReason.CLIENT_INITIATED);
	public final static EReason REASON_SERVER_INITIATED =
		new EReason(EReason.SERVER_INITIATED);
	public final static EReason REASON_IO_ERROR = new EReason(EReason.IO_ERROR);

	/**
	 * EState 是一個枚舉類，為當前連接到服務器的狀態。
	 *
	* @author  listlike <a href="mailto:listlike@hotmail.com">
 	*                      <i>&lt;listlike@hotmail.com&gt;</i></a>
	*/
	
	public static final class EState
	{
		/* EState 枚舉值常數 */
		public final static int NOT_SET = -1;
		public final static int DISCONNECTED = 0;
		public final static int CONNECTING = 1;
		public final static int CONNECTED = 2;

		/** 保存當前值 - 默認值為 'not set' */
		private int value = NOT_SET;

		/**
		 * 建立 <code>EState</code> 實例.
		 *
		 * @param newVal an <code>int</code> 值，當前的連接狀態。
		 * @exception IllegalArgumentException 狀態值不正確
		 */
		protected EState(int newVal) throws IllegalArgumentException
		{
			if ((newVal < -1) || (newVal > 2))
				throw new IllegalArgumentException("Invalid Enumeration Value");
			value = newVal;
		}

		/**
		 * 當前值的字符顯示.
		 *
		 * @return a <code>String</code> 枚舉值的名稱
		 */
		public String toString()
		{
			switch (value)
			{
				case NOT_SET :
					return "NOT_SET";
				case DISCONNECTED :
					return "DISCONNECTED";
				case CONNECTING :
					return "CONNECTING";
				case CONNECTED :
					return "CONNECTED";
				default :
					return "Internal Error";
			}
		}

		/**
		 * <code>getValue</code> 得到當前的值。
		 *
		 * @return  <code>int</code> 當前的值。
		 */
		public int getValue()
		{
			return value;
		}
	}
	
	/**
	* EReason 是一個枚舉類，當前服務器連接狀態改變的原因。
	*
	* @author  listlike <a href="mailto:listlike@hotmail.com">
	*                      <i>&lt;listlike@hotmail.com&gt;</i></a>
	*/
	
	public final static class EReason
	{
		/* EReason 枚舉的值  */
		public static final int NOT_SET = -1;
		public static final int CLIENT_INITIATED = 0;
		public static final int SERVER_INITIATED = 1;
		public static final int IO_ERROR = 2;
		
		/** 保存當前值  */
		private int value;

		/**
		* 建立 <code>EReason</code> 實例.
		*
		* @param reason an <code>int</code> 值，改變的原因。
	    * @exception IllegalArgumentException 狀態值不正確
		*/
		protected EReason(int reason) throws IllegalArgumentException
		{
			if ((reason < -1) || (reason > 2))
				throw new IllegalArgumentException("Invalid Enumeration Value");
			value = reason;
		}
		/**
		 * <code>getValue</code> 返回當前枚舉類型響應的值.
		 *
		 * @return  <code>int</code> 當前枚舉類型響應的值
		 */
		public int getValue()
		{
			return value;
		}

		/**
		 * 當前值的字符顯示.
		 *
		 * @return a <code>String</code> 枚舉值的名稱
		 */
		public String toString()
		{
			switch (value)
			{
				case NOT_SET :
					return "NOT_SET";
				case CLIENT_INITIATED :
					return "CLIENT_INITIATED";
				case SERVER_INITIATED :
					return "SERVER_INITIATED";
				case IO_ERROR :
					return "IO_ERROR";
				default :
					return "Internal Error";
			}
		}
	}

	private EState state, oldState;
	private EReason reason;

	/**
	 * 建立一個新的<code>ConnectionEvent</code> 實例.這個方法因該僅僅被ConnectionBean調用
	 *
	 * @param source an <code>Object</code> 當前的ConnectionBean；
	 * @param state an <code>Estate</code> 新的狀態
	 * @param oldState an <code>EState</code> 老的狀態
	 * @param reason an <code>Estate</code> 改變原因
	 */
	public ConnectionEvent(
		Object source,
		EState state,
		EState oldState,
		EReason reason)
	{
		super(source);
		this.state = state;
		this.oldState = oldState;
		this.reason = reason;
	}

	/**
	 * <code>getState</code> 當這個事件發生后，連接所處的狀態。
	 *
	 * @return an <code>EState</code> 當前的狀態
	 */
	public EState getState()
	{
		return state;
	}

	/**
	 * <code>getOldState</code> 當這個事件發生前，連接所處的狀態。
	 *
	 * @return an <code>EState</code> 老的狀態
	 */
	public EState getOldState()
	{
		return oldState;
	}

	/**
	 * <code>getReason</code> 返回狀態改變的原因, 包括這些原因：連接失敗 ，客戶端請求斷開，服務器請求斷開。
	 *
	 * @return an <code>EReason</code> 改變原因
	 */
	public EReason getReason()
	{
		return reason;
	}
}