/* Simple argument-parsing class
 * Copyright (C) 2001 Patrick E. Pelletier <ppelleti@users.sourceforge.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**
 * Copyright (C) 2006-2007  NTT DATA CORPORATION
 * 
 * Version: 1.0.0 2007/04/01
 *  
 */
package net.cellcomputing.himawari.argparse;

import net.cellcomputing.himawari.accessory.primitive.p_boolean;

/**
 * オプションの詳細パラメータ(boolean型)の設定を行うクラス。
 * @author NTT DATA Corporation
 */
strictfp class FlagHandler extends OptionHandler
{
	/**
	 * オプションの否定状態
	 */
	public boolean allow_negation;
	/**
	 * オプションの解析状態(解析済み or 未解析)
	 */
	public boolean already_used;
	/**
	 * オプションの詳細パラメータ
	 */
	public p_boolean value;

	/**
	 * コンストラクタ
	 * @param usage_in	用法メッセージ	
	 * @param value_in	オプションの詳細パラメータ
	 * @param allow_negation_in	否定状態
	 */
	public FlagHandler(String usage_in, p_boolean value_in, boolean allow_negation_in)
	{
		super(usage_in);
		allow_negation = allow_negation_in;
        already_used = false; 
        value = value_in;
	}
	
	/**
	 * オプションのパラメータの有無の判定。<br>
	 * パラメータがboolean型の場合のみfalseを返す。
	 * @return false
	 * @see net.cellcomputing.himawari.argparse.OptionHandler#takesarg()
	 */
	public boolean takesarg()
	{
		return false;
	}
	
	/**
	 * オプションの否定状態を判定。<br>
	 * オプション名に"no"が付いていればtrue
	 * @return allow_nagation
	 * @see net.cellcomputing.himawari.argparse.OptionHandler#allownegation()
	 */
	public boolean allownegation()
	{
		return allow_negation;
	}
	
	/**
	 * パラメータの解析をリセット(未解析の状態に戻す)
	 * @see net.cellcomputing.himawari.argparse.OptionHandler#reset()
	 */
	public void reset()
	{
		already_used = false;
	}
	
	/**
	 * 入力オプションの有効性を判断し、メッセージを返す。
	 * @return	"negated flag used with non-negated flag"
	 * @return	"" 
	 * @see net.cellcomputing.himawari.argparse.OptionHandler#handlearg(java.lang.String)
	 */
	public String handlearg(String arg)
	{
		boolean newvalue = (arg.length() == 0);
		
//		すでに入力されているオプションかどうかを判定
	    if (already_used) {
	        if (newvalue != value.value){
	            return "negated flag used with non-negated flag";
	        }
	    } 
	    else {
	        value.value = newvalue;
	        already_used = true;
	    }
	    return "";
	}
}
