/**
 * IgaLib -> String
 * Copyright (C) 2001  Tosiki IGA , IgaLib project member
 *   (http://homepage2.nifty.com/igat/igapyon/index.html)
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package jp.ne.nifty.iga.tosiki.string;

import java.io.*;

/**
 * 敿妏僇僞僇僫傪慡妏曄姺傪峴偆Reader僋儔僗偱偡丅<BR>
 * 偙偺僋儔僗傪棙梡偡傞偲 敿妏僇僞僇僫偺暥帤楍傪 慡妏偵曄姺偟側偑傜
 * 張棟傪恑傔偰偄偒傑偡丅戺壒傕張棟懳徾偲側偭偰偍傝傑偡丅
 * 敿妏戺壒偼揔愗側慡妏戺壒傊偲曄姺偝傟傑偡丅側偍 敿妏ANK側偳偼張棟懳徾奜偵側傝傑偡丅
 *
 * @author Tosiki IGA
 */
public class ReplaceReader
	extends Reader
{
	protected Reader reader=null;
	protected String strFind=null;
	protected String strDest=null;
	protected int iSearchWordLength=-1;
	protected boolean isEndOfStream=false;

	/**
	 * 撉傒崬傒僶僢僼傽
	 */
	protected char[] aryBufOfReader=null;
	protected int iAryBufOfReaderPoint=0;
	protected int iAryBufOfReaderLength=0;

	/**
	 * 専嶕暥帤楍偑堦抳偡傞傑偱曐棷偟偰偍偔儚乕僋Writer
	 */
	protected CharArrayWriter writerWork=new CharArrayWriter();

	/**
	 * 抲姺Reader僋儔僗偺僐儞僗僩儔僋僞
	 *
	 *   @param Reader reader   楢寢偡傞尦偺Reader
	 *   @param String strFind  専嶕偡傞暥帤楍
	 *   @param String strDest  専嶕僸僢僩偟偨応崌偵抲姺偡傞暥帤楍
	 */
	public ReplaceReader(Reader reader,String strFind,String strDest)
	{
		this.reader=reader;
		this.strFind=strFind;
		this.strDest=strDest;
		iSearchWordLength=strFind.length();
	}

	/**
	 * 1暥帤Reader偐傜撉傒崬傒傑偡丅
	 *
	 * @return int 撉傒崬傫偩暥帤楍
	 * @throws IOException 壗偐偟傜偺I/O椺奜
	 */
	public int read()
		throws IOException
	{
		if(iAryBufOfReaderPoint<iAryBufOfReaderLength)
		{
			return aryBufOfReader[iAryBufOfReaderPoint++];
		}

		if(isEndOfStream)
		{
			return -1;
		}

		// 専嶕曐棷暥帤楍偺弶婜壔
		writerWork.reset();

		for(int iSearchPoint=0;;iSearchPoint++)
		{
			int iRead=reader.read();
			if(iRead<0)
			{
				isEndOfStream=true;
				break;
			}

			// 専嶕曐棷暥帤楍偵捛壛
			writerWork.write(iRead);

			if(iRead!=strFind.charAt(iSearchPoint))
			{
				break;
			}

			// 擖椡暥帤楍偲僸僢僩拞
			if((iSearchPoint+1)==iSearchWordLength)
			{
				// 抲姺偑姰慡僸僢僩
				// 専嶕曐棷暥帤楍偺撪梕偼攋婞偟偰丄抲姺屻暥帤楍偵抲姺偟傑偡丅
				writeBufToBuffer(strDest.toCharArray());
				return read();
			}
		}

		// 抲姺偼僸僢僩偟側偐偭偨偺偱丄専嶕曐棷暥帤楍傪COMMIT丅
		writeBufToBuffer(writerWork.toCharArray());
		return read();
	}

	protected void writeBufToBuffer(char[] arg)
		throws IOException
	{
		aryBufOfReader=arg;
		iAryBufOfReaderPoint=0;
		iAryBufOfReaderLength=aryBufOfReader.length;
	}

	/**
	 * 暥帤攝楍傪Reader偐傜撉傒崬傒傑偡丅<BR>
	 * 2001.08.14 慡偔僶僌偭偰偄偨偺偱廋惓偟傑偟偨丅JUnit梡僐乕僪傪婰嵹偟傑偟偨丅<BR>
	 *
	 * @param char cbuf[] 撉傒崬傒愭僶僢僼傽
	 * @param int off 撉傒崬傒愭僶僢僼傽偺僆僼僙僢僩
	 * @param int len 撉傒崬傒壜擻側嵟戝挿偝
	 * @return int 撉傒崬傫偩暥帤楍偺挿偝
	 * @throws IOException 壗偐偟傜偺I/O椺奜
	 */
	public final int read(char cbuf[], int off, int len)
		throws IOException
	{
		if(isEndOfStream)
		{
			return -1;
		}

		int iNumberOfCharacters=0;
		int iTill=off+len;
		for(int index=off;index<iTill;index++)
		{
			int iRead=read();
			if(iRead<0)
			{
				isEndOfStream=true;
				break;
			}
			cbuf[index]=(char)iRead;
			iNumberOfCharacters++;
		}
		return iNumberOfCharacters;
	}

	/**
	 * Reader傪僋儘乕僘偟傑偡
	 *
	 * @throws IOException 壗偐偟傜偺I/O椺奜偺敪惗
	 */
	public final void close()
		throws IOException
	{
		if(reader!=null)
		{
			reader.close();
			reader=null;
		}
	}
}