/*
 * GNU LESSER GENERAL PUBLIC LICENSE Copyright (C) 2006 The Lobo Project
 * 
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 * 
 * Contact info: xamjadmin@users.sourceforge.net
 */
/*
 * Created on Nov 13, 2005
 */
package org.cobra_grendel.html.io;

import java.io.IOException;
import java.io.LineNumberReader;
import java.io.Reader;

public class WritableLineReader extends LineNumberReader
{
    private final Reader delegate;

    private StringBuffer writeBuffer = null;

    public WritableLineReader(final Reader reader)
    {
        super(reader);
        delegate = reader;
    }

    public WritableLineReader(final Reader reader, final int bufferSize)
    {
        super(reader, bufferSize);
        delegate = reader;
    }

    /*
     * (non-Javadoc) Note: Not implicitly thread safe.
     * 
     * @see java.io.Reader#close()
     */
    @Override
    public void close() throws IOException
    {
        writeBuffer = null;
        super.close();
    }

    /*
     * Note: Not implicitly thread safe.
     */
    @Override
    public int read() throws IOException
    {
        StringBuffer sb = writeBuffer;
        if (sb != null && sb.length() > 0)
        {
            char ch = sb.charAt(0);
            sb.deleteCharAt(0);
            if (sb.length() == 0)
            {
                writeBuffer = null;
            }
            return ch;
        }
        return super.read();
    }

    /*
     * (non-Javadoc) Note: Not implicitly thread safe.
     * 
     * @see java.io.Reader#read(byte[], int, int)
     */
    @Override
    public int read(final char[] b, final int off, final int len) throws IOException
    {
        StringBuffer sb = writeBuffer;
        if (sb != null && sb.length() > 0)
        {
            int srcEnd = Math.min(sb.length(), len);
            sb.getChars(0, srcEnd, b, off);
            sb.delete(0, srcEnd);
            if (sb.length() == 0)
            {
                writeBuffer = null;
            }
            return srcEnd;
        }
        return super.read(b, off, len);
    }

    @Override
    public boolean ready() throws IOException
    {
        StringBuffer sb = writeBuffer;
        if (sb != null && sb.length() > 0)
        {
            return true;
        }
        return super.ready();
    }

    /**
     * Note: Not implicitly thread safe.
     * 
     * @param text
     * @throws IOException
     */
    public void write(final String text) throws IOException
    {
        // Document overrides this to know that new data is coming.
        StringBuffer sb = writeBuffer;
        if (sb == null)
        {
            sb = new StringBuffer();
            writeBuffer = sb;
        }
        sb.append(text);
    }
}