/**
 * <copyright> Copyright (c) 2006 by Know-Center, Graz, Austria </copyright>
 * 
 * This software is the confidential and proprietary information of Know-Center,
 * Graz, Austria. You shall not disclose such Confidential Information and shall
 * use it only in accordance with the terms of the license agreement you entered
 * into with Know-Center.
 * 
 * KNOW-CENTER MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT. KNOW-CENTER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
 * LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES.
 * 
 * $Id: Utils.java,v 1.3 2006/10/31 08:13:02 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.pdf;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;

/**
 * Abstract class that contains helpful utility functions used by the digital
 * signatures.
 * 
 * @author wprinz
 */
public abstract class Utils
{

  /**
   * Extracts the pure content text from a given content stream.
   * 
   * <p>
   * The pure content text is just an assembly of all strings that occur within the content stream in
   * stream order.
   * Each of these strings will be set on a new line.
   * </p>
   * 
   * @param stream_bytes The content stream.
   * @return Returns the extracted string.
   * @throws IOException Forwarded exception.
   */
  public static String extractPureTextFromContentStream(
      final byte[] stream_bytes) throws IOException
  {

    // logger_.debug("stream_bytes:");
    // logger_.debug(new String(stream_bytes, "US-ASCII"));
    // logger_.debug(":end of stream_bytes");

    final byte OPEN = '(';
    final byte CLOSE = ')';

    StringWriter strwrtr = new StringWriter();
    PrintWriter printer = new PrintWriter(strwrtr);
    int open_index = -1;
    int close_index = -1;
    for (int i = 0; i < stream_bytes.length; i++)
    {
      if (stream_bytes[i] == OPEN)
      {
        open_index = i;
        continue;
      }
      if (stream_bytes[i] == CLOSE)
      {
        close_index = i;

        // logger_.debug("open = " + open_index + ", close = " +
        // close_index);

        int len = close_index - open_index - 1;
        // logger_.debug("len = " + len);

        byte[] bytes = new byte[len];
        System.arraycopy(stream_bytes, open_index + 1, bytes, 0, len);

        String str = new String(bytes, "ISO-8859-1");
        // logger_.debug("string = " + str);

        printer.println(str);

        continue;
      }
    }
    strwrtr.close();
    String signature_text = new String(strwrtr.getBuffer());
    // logger_.debug(signature_text);

    return signature_text;
  }

}