/**
 * <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: Normalizer.java,v 1.5 2006/10/31 08:20:56 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.tools;

import java.io.Serializable;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

import at.knowcenter.wag.egov.egiz.cfg.ConfigLogger;
import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
import at.knowcenter.wag.egov.egiz.exceptions.NormalizeException;
import at.knowcenter.wag.egov.egiz.exceptions.SettingsException;

/**
 * This class provides wrapper methods to get an access to different normalizer implementations.
 * <br>
 * This class is to load the corresponding implementation of a normalizer class. Therefor it seams
 * to be a factory. The factory settings are read from the configuration file calling the
 * SettingsReader.
 * 
 * @author wlackner
 * @see at.knowcenter.wag.egov.egiz.tools.Normalizer
 * @see at.knowcenter.wag.egov.egiz.tools.NormalizeV01
 * @see at.knowcenter.wag.egov.egiz.cfg.SettingsReader
 */
public class Normalizer implements Serializable {
// 04.11.2010 changed by exthex - normalize methods use and propagate the keepMultipleNewlines parameter

  /**
   * SVUID.
   */
  private static final long serialVersionUID = 4201772508393848555L;
  
  /**
   * The current raw string to normalize
   */
  private String rawString_ = null;
  /**
   * The current normalisation version string
   */
  private String normVersion_ = null;
  /**
   * The normalized string cache
   */
  private String normString_ = null;
  /**
   * The reference to the normalizer implementation
   */
  private Normalize normalize_ = null;
//  /**
//   * A given Encoding, not used now
//   */
//  private String encoding_ = null;
  /**
   * The SettingsReader instance
   */
  private SettingsReader settings_ = null;
  /**
   * The factory class prefix
   */
  private final static String CLASS_PREFIX = ".Normalize";
  /**
   * The default version string
   */
  protected final static String DEFAULT_VERSION = "V01";
  /**
   * The settings key defined in the settings file
   * 
   * @see SettingsReader
   */
  protected final static String SETTINGS_VERSION_KEY = "normalizer.version";
  /**
   * The logger definition.
   */
  private static final Logger logger_ = ConfigLogger.getLogger(Normalizer.class);

  /**
   * New Normalizer init by the raw string and a normalizer version.
   * 
   * @param rawString the raw string to normalize
   * @param normVersion the nomalizer version that should be used
   * @throws NormalizeException ErrorCode:400
   */
  public Normalizer(String rawString, String normVersion) throws NormalizeException {
    rawString_ = rawString;
    normVersion_ = normVersion;
    init();
  }

  /**
   * New Normalizer init by the raw string.
   * 
   * @param rawString the raw string to normalize
   * @throws NormalizeException ErrorCode:400
   */
  public Normalizer(String rawString) throws NormalizeException {
    rawString_ = rawString;
    init();
  }

  /**
   * The empty constructor.
   * 
   * @throws NormalizeException ErrorCode:400
   */
  public Normalizer() throws NormalizeException {
    init();
  }

  /**
   * Load the factory implementation. This method trys to load the configured normalizer library.
   * 
   * @throws NormalizeException
   */
  public void init() throws NormalizeException {
    loadSettings();
    String class_name = this.getClass().getPackage().getName() + getClassName();
    Class normalize_class = null;
    try {
      normalize_class = Class.forName(class_name);
    } catch (ClassNotFoundException e) {
      if (logger_.isEnabledFor(Level.FATAL)) {
        logger_.fatal("Class not found:" + class_name);
      }
      throw new NormalizeException("Can not load normalizer library", e);
    }
    try {
      normalize_ = (Normalize) normalize_class.newInstance();
    } catch (InstantiationException e) {
      if (logger_.isEnabledFor(Level.FATAL)) {
        logger_.fatal("Can not instantiate:" + class_name);
      }
      throw new NormalizeException("Can not load normalizer library", e);
    } catch (IllegalAccessException e) {
      if (logger_.isEnabledFor(Level.FATAL)) {
        logger_.fatal("Can not access:" + class_name);
      }
      throw new NormalizeException("Can not load normalizer library", e);
    }
  }
  
  /**
   * Returns the underlying normalizer instance.
   * @author tknall
   */
  public Normalize getInstance() {
	  return this.normalize_;
  }

  /**
   * Read the class postfix from the configuration file
   * 
   * @return the full qualified class name
   */
  private String getClassName() {
    if (normVersion_ == null) {
      normVersion_ = settings_.getSetting(SETTINGS_VERSION_KEY, DEFAULT_VERSION);
    }
    return CLASS_PREFIX + normVersion_;
  }

  /*
   * public void setEncoding(String encoding) { encoding_ = encoding; }
   */

  /**
   * Set the raw string to normalize
   */
  public void setRawString(String rawString) {
    rawString_ = rawString;
  }

//  /**
//   * Return the normalized string. If the chached value does not exist the normalize method from the
//   * current normalizer implementation is called.
//   * 
//   * @return the normalized string
//   */
//  public String getNormalizedString() {
//    if (normString_ == null) {
//      normalize();
//    }
//    return normString_;
//  }

  /**
   * Set a normalizer version. This activity load the new requested normalizer implementation.
   * 
   * @param normVersion the normalizer version to be use
   * @throws NormalizeException ErrorCode:400
   */
  public void setVersion(String normVersion) throws NormalizeException {
    normVersion_ = normVersion;
    init();
  }

  /**
   * Return the current version string.
   * 
   * @return the normaliser version string
   */
  public String getVersion() {
    return normVersion_;
  }

  /**
   * Wrapper method. Call the normalizer implementation method.
   * 
   * @param rawString the raw string to normalize
 * @param keepMultipleNewlines 
   * @return the normalized string
   * @see NormalizeV01
   */
  public String normalize(String rawString, boolean keepMultipleNewlines) {
    return normalize_.normalize(rawString, keepMultipleNewlines);
  }

  /**
   * Wrapper method. Call the normalizer implementation method. Normalize the current raw string.
   * 
   * @return the normalized string
   * @see NormalizeV01
   */
  public String normalize(boolean keepMultipleNewlines) {
    if (normString_ == null) {
      normString_ = normalize(rawString_, keepMultipleNewlines);
    }
    return normString_;
  }

  /**
   * Returns the normalizer line separator string.
   * @return the line separator string
   */
  public String getNormCR() {
    return normalize_.getNormCR();
  }  
  
  /**
   * load the class settings
   * 
   * @throws NormalizeException
   * @see SettingsReader
   */
  private void loadSettings() throws NormalizeException {
    if (settings_ == null) {
      try {
        settings_ = SettingsReader.getInstance();
      } catch (SettingsException e) {
        String log_message = "Can not load normalizer settings. Cause:\n" + e.getMessage();
        logger_.error(log_message, e);
        throw new NormalizeException(log_message, e);
      }
    }
  }
}