/*
    * Zemucan: A Syntax Assistant for DB2
    * Copyright (C) 2009, 2010 Andres Gomez Casanova
    *
    * This file is part of Zemucan.
    *
    * Zemucan 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 3 of the License, or
   * (at your option) any later version.
   *
   * Zemucan 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, see <http://www.gnu.org/licenses/>.
   *
   * Contact:
   * a n g o c a  at  y a h o o  dot  c o m
   * Cra. 45 No 61 - 31, Bogota, Colombia.
   *
   * Author:   $LastChangedBy: angoca $:
   * Date:     $LastChangedDate: 2011-03-07 00:34:33 -0500 (lun, 07 mar 2011) $:
   * Revision: $LastChangedRevision: 1924 $:
   * URL:      $HeadURL: https://zemucan.svn.sourceforge.net/svnroot/zemucan/branches/zemucan_v1/source-code/uiImplJLine/src/main/java/name/angoca/zemucan/ui/impl/jline/ZemucanCompletor.java $:
   */
  package name.angoca.zemucan.ui.impl.jline;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import jline.Completor;
  import name.angoca.zemucan.AbstractZemucanException;
  import name.angoca.zemucan.interfaze.InterfaceCore;
  import name.angoca.zemucan.interfaze.model.ReturnOptions;
  import name.angoca.zemucan.tools.messages.jline.Messages;
  import name.angoca.zemucan.ui.api.InputReader;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * This is the implementation of a JLine Completor. This class permits to search
   * the options from the core and show them via Jline.
   * <p>
   * <b>Control Version</b>
   * <p>
   * <ul>
   * <li>0.0.1 Class creation.</li>
   * <li>0.0.2 Logger messages.</li>
   * <li>0.0.3 No override, no supress warnings.</li>
   * <li>0.0.4 finals.</li>
   * <li>1.0.0 Moved to version 1.</li>
   * <li>1.0.1 Strings externalized.</li>
   * <li>1.0.2 Asserts.</li>
   * <li>1.1.0 Renamed.</li>
   * <li>1.1.1 Completion handler.</li>
   * <li>1.1.2 Assistance fixed.</li>
   * </ul>
   *
   * @author Andres Gomez Casanova <a
   *         href="mailto:a n g o c a at y a h o o dot c o m" >(AngocA)</a>
   * @version 1.1.2 2010-06-04
   */
  public class ZemucanCompletor implements Completor {
      /**
       * Logger.
       */
      private static final Logger LOGGER = LoggerFactory
              .getLogger(ZemucanCompletor.class);
  
      /**
       * Assertion activation.
       */
      private boolean assertsEnabled;
  
      /**
       * Default constructor.
       */
      ZemucanCompletor() {
          this.assertsEnabled = false;
          // Intentional side-effect!
          assert this.assertsEnabled = true;
      }
  
      /*
       * (non-Javadoc)
       *
       * @see jline.Completor#complete(java.lang.String, int, java.util.List)
       */
      // The interface is generic, so there is a warning here.
      @Override
      @SuppressWarnings("unchecked")
      public final int complete(final String/* ! */buffer, final int cursor,
              @SuppressWarnings("rawtypes") final List/* <!>! */candidateRaw) {
          assert buffer != null;
         assert candidateRaw != null;
         if (this.assertsEnabled) {
             for (final Object object : candidateRaw) {
                 assert object != null;
             }
         }
 
         final List<String> candidates = candidateRaw;
 
         ZemucanCompletor.LOGGER.debug(
                 "Completor before: buffer '{}', cursor: {}", //$NON-NLS-1$
                 buffer, Integer.valueOf(cursor));
 
         final String phrase = buffer.substring(0, cursor);
         try {
             final ReturnOptions answer = InterfaceCore.analyzePhrase(phrase);
 
             // The first candidate is the new phrase.
             final String complete = answer.getPhrase().toLowerCase();
 
             // borra los espacios
             final String trim = phrase.trim().toLowerCase();
 
             // Compara si son iguales
             if (complete.startsWith(trim)) {
                 // Toma la diferencia
                 String diff = complete.substring(trim.length());
                 if (diff.startsWith(" ") && phrase.endsWith(" ")) {
                     diff = diff.substring(1, diff.length());
                 }
                 candidates.add(diff);
                 ZemucanCompletor.LOGGER.debug("Diff '" + diff + "'");
             } else {
                 candidates.add("");
             }
 
             // There are options or phrases, then add them as
             // candidate. There is not a predefined phrase.
             candidates.addAll(this.fromArrayToColletion(answer.getPhrases()));
             candidates.addAll(this.fromArrayToColletion(answer.getOptions()));
             // Adds a dummy option, in order to prevent that
             // jLine adds automatically the option as a phrase.
             if ((candidates.size() == 2) && (answer.getOptions().length == 1)
                     && (answer.getPhrases().length == 0)) {
                 candidates.add("");
             }
         } catch (final AbstractZemucanException e) {
             String cause = "";
             if (e.getCause() != null) {
                 cause = e.getCause().toString();
             }
             ZemucanCompletor.LOGGER.error(
                     Messages.getString("ZemucanCompletor.JLINE1-Exception"), //$NON-NLS-1$
                     new String[] { e.getMessage(), cause });
             if (e.getCause() != null) {
                 final Throwable ex = e.getCause();
                 ZemucanCompletor.LOGGER.error(Messages.getString("ZemucanCompletor" //$NON-NLS-1$
                         + ".JLINE2-SpecificProblem"), //$NON-NLS-1$
                         new String[] { e.getMessage(), cause, ex.getMessage(),
                                 ex.getCause().toString() });
             }
             System.exit(InputReader.ASSISTING_ERROR);
         }
 
         ZemucanCompletor.LOGGER.debug("Completor after: buffer '{}', cursor: {}", //$NON-NLS-1$
                 buffer, Integer.valueOf(cursor));
         return cursor;
     }
 
     /**
      * Converts a array into a collection.
      *
      * @param array
      *            array to convert.
      * @return Collection.
      */
     private Collection<String>/* <!>! */fromArrayToColletion(
             final String[]/* [!]! */array) {
         assert array != null;
         if (this.assertsEnabled) {
             for (final String string : array) {
                 assert string != null;
             }
         }
 
         final List<String> collection = new ArrayList<String>();
         for (final String string : array) {
             collection.add(string);
         }
 
         assert collection != null;
         if (this.assertsEnabled) {
             for (final String string : collection) {
                 assert string != null;
             }
         }
         return collection;
     }
 }