/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *
 * $Id: NormalizeV01.java,v 1.5 2006/10/31 08:20:56 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.tools;

import java.io.Serializable;

/**
 * This ist the first version implementing a normalizer method. The normalize statements are
 * performed by using regular expressions.
 * 
 * @author wlackner
 */
public class NormalizeV01 implements Normalize, Serializable {
// 04.11.2010 change by exthex - added keepMultipleLineBreaks parameter to normalize method 
// to allow multiple line breaks to not be normalized to a single one
  /**
   * SVUID.
   */
  private static final long serialVersionUID = 2302956630639871601L;
  
  /**
   * The space string
   */
  private final static String NORM_SP = " "; //\u0020
  /**
   * The line break string --> use only \n because XML-Parser ignores \r\n
   */
  private final static String NORM_CR = "\n"; //
  /**
   * The apostrophe string
   */
  private final static String NORM_AP = "'"; //\u0027
  /**
   * The quotation mark string
   */
  private final static String NORM_QU = "\""; //\u0022
  /**
   * The hypens string
   */
  private final static String NORM_HY = "-"; //\u002D
  /**
   * The current version string
   */
  protected static final String VERSION = "V01";

  /**
   * The empty constructor.
   */
  public NormalizeV01() {
  }

  /**
   * The normalizer implementation. <br>
   * Normalizer algorithums:
   * <ol>
   * <li>code all multiple line breaks as \n\n</li>
   * <li>replace all Tabs and form feeds with spaces</li>
   * <li>code line breaks as \n</li>
   * <li>reduce all multiple line breaks into one line break (only if keepMultipleLineBreaks == false), code line break as \r</li>
   * <li>replace all single line breaks with space</li>
   * <li>normalize spaces</li>
   * <li>remove spaces before and after a line break</li>
   * <li>remove leading and trailing space or line break in the string</li>
   * <li>normalize line breaks</li>
   * <li>normalize apostrophes</li>
   * <li>normalize quotations</li>
   * <li>normalize hypens</li>
   * </ol>
   * 
   * @param rawText the text to normalize
   * @param keepMultipleLineBreaks if true, multiple newlines in a row will not be normalized to a single line break
   * @see at.knowcenter.wag.egov.egiz.tools.Normalize#normalize(java.lang.String)
   */
  public String normalize(String rawText, boolean keepMultipleLineBreaks) {
    if (rawText == null || rawText.equals("null") || rawText.length() == 0) {
      return "";
    }
    String normText = rawText;

    // replace all null values
    normText = normText.replaceAll("\u0000+", "");

    // replace all Tabs and form feeds with spaces
    normText = normText.replaceAll("[\t\f]", NORM_SP);

    // replace all non breaking spaces with normal spaces
    normText = normText.replaceAll("\u00a0+", NORM_SP);

    // code all windows line breaks as \n
    normText = normText.replaceAll("\r\n", "\n");

    // code all mac line breaks as \n
    normText = normText.replace('\r', '\n');

    if (!keepMultipleLineBreaks)
    {
      // reduce all multiple line breaks into two line breaks, code muliple line break as \r\r
      normText = normText.replaceAll("\n[\\s\n]*\n", "\r\r");
    }

    // replace all single line breaks with one line break
    normText = normText.replace('\n', '\r');

    // normalize spaces
    normText = normText.replaceAll(" +", NORM_SP);

    // remove spaces before and after a single line break
    normText = normText.replaceAll(" ?\r ?", "\r");

    if (keepMultipleLineBreaks)
    {
      // remove spaces before and after a multiple line breaks
      normText = normText.replaceAll(" ?\r\r ?", "\r\r");
    } else
    {
      normText = normText.replaceAll(" ?\r\r ?", "\r");
    }

    // remove leading and trailing space or line break in the string
    int start_idx = (normText.charAt(0) == ' ' || normText.charAt(0) == '\r' ? 1 : 0);
    int end_idx = (normText.charAt(normText.length() - 1) == ' ' || normText.charAt(normText.length() - 1) == '\r' ? normText.length() - 1 : normText.length());
    if (end_idx < start_idx) {
      end_idx = start_idx;
    }
  
    //    System.err.println("Start idx:" + start_idx + " End idx:" + end_idx + " Text length:" +
    // normText_.length());
    normText = normText.substring(start_idx, end_idx);
    
    // normalize line breaks
    normText = normText.replaceAll("\r", NORM_CR);

    // normalize apostrophes
    normText = normText.replaceAll("[\u0060\u00B4\u2018\u2019\u201A\u201B]", NORM_AP);

    // normalize quotations
    normText = normText.replaceAll("[\u201C\u201D\u201E\u201F]", NORM_QU);

    // normalize hypens
    normText = normText.replaceAll("[\u00AD\u2013\u2014]", NORM_HY);

    return normText;
  }

  /**
   * Return the version string.
   * 
   * @see at.knowcenter.wag.egov.egiz.tools.Normalize#getVersion()
   */
  public String getVersion() {
    return VERSION;
  }

  /**
   * Returns the normalizer line separator string.
   * @return the line separator string
   */
  public String getNormCR() {
    return NORM_CR;
  }
}