/*
 * JAVE - A Java Audio/Video Encoder (based on FFMPEG)
 * 
 * Copyright (C) 2008-2009 Carlo Pelliccia (www.sauronsoftware.it)
 * 
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
package it.sauronsoftware.jave;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;

/**
 * A package-private utility extending java.io.BufferedReader. If a line read
 * with {@link RBufferedReader#readLine()} is not useful for the calling code,
 * it can be re-inserted in the stream. The same line will be returned again at
 * the next readLine() call.
 * 
 * @author Carlo Pelliccia
 */
class RBufferedReader extends BufferedReader {

	/**
	 * Re-inserted lines buffer.
	 */
	private ArrayList<String> lines = new ArrayList<String>();

	/**
	 * It builds the reader.
	 * 
	 * @param in
	 *            The underlying reader.
	 */
	public RBufferedReader(Reader in) {
		super(in);
	}

	/**
	 * It returns the next line in the stream.
	 */
	public String readLine() throws IOException {
		if (lines.size() > 0) {
			return (String) lines.remove(0);
		} else {
			return super.readLine();
		}
	}

	/**
	 * Reinserts a line in the stream. The line will be returned at the next
	 * {@link RBufferedReader#readLine()} call.
	 * 
	 * @param line
	 *            The line.
	 */
	public void reinsertLine(String line) {
		lines.add(0, line);
	}

}
