001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.cli.completers;
021
022import org.crsh.cli.descriptor.ParameterDescriptor;
023import org.crsh.cli.spi.Completion;
024import org.crsh.cli.type.ValueType;
025import org.crsh.cli.spi.Completer;
026
027import java.lang.reflect.Method;
028
029public class EnumCompleter implements Completer {
030
031  /** . */
032  private static final EnumCompleter instance = new EnumCompleter();
033
034  /**
035   * Returns the empty completer instance.
036   *
037   * @return the instance
038   */
039  public static EnumCompleter getInstance() {
040    return instance;
041  }
042
043  public Completion complete(ParameterDescriptor parameter, String prefix) throws Exception {
044    if (parameter.getType() == ValueType.ENUM) {
045      Completion.Builder builder = null;
046      Class<?> vt = parameter.getDeclaredType();
047      Method valuesM = vt.getDeclaredMethod("values");
048      Method nameM = vt.getMethod("name");
049      Enum<?>[] values = (Enum<?>[])valuesM.invoke(null);
050      for (Enum<?> value : values) {
051        String name = (String)nameM.invoke(value);
052        if (name.startsWith(prefix)) {
053          if (builder == null) {
054            builder = Completion.builder(prefix);
055          }
056          builder.add(name.substring(prefix.length()), true);
057        }
058      }
059      return builder != null ? builder.build() : Completion.create();
060    } else {
061      return Completion.create();
062    }
063  }
064}