/*******************************************************************************
    * Copyright (c) 2007, 2014 Massimiliano Ziccardi
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *******************************************************************************/
  package it.jnrpe.server.console;
  
  import static jline.internal.Preconditions.checkNotNull;
  import it.jnrpe.commands.CommandDefinition;
  import it.jnrpe.commands.CommandRepository;
  import it.jnrpe.plugins.IPluginRepository;
  import it.jnrpe.plugins.PluginDefinition;
  
  import java.util.Collection;
  import java.util.List;
  import java.util.SortedSet;
  import java.util.TreeSet;
  
  import jline.console.completer.Completer;
  
  /**
   * The command completer.
   * We cannot use a simple StringCompleter since we have to perform case
   * insensitive completion.
   *   
   * @author Massimiliano Ziccardi
   */
  class CommandCompleter implements Completer {
  
          private final SortedSet<String> strings = new TreeSet<String>();
  
          public CommandCompleter(final IPluginRepository pluginRepository, final CommandRepository commandRepository) {
              
              for (PluginDefinition pd : pluginRepository.getAllPlugins()) {
                  strings.add(PluginCommand.NAME + pd.getName().toLowerCase());
              }
              
              for (CommandDefinition cd : commandRepository.getAllCommands()) {
                  strings.add(CommandConsoleCommand.NAME + cd.getName().toLowerCase());
              }
              
              strings.add(ExitCommand.NAME.toLowerCase());
              strings.add(HelpCommand.NAME.toLowerCase());
          }
          
          public Collection<String> getStrings() {
              return strings;
          }
  
          public int complete(final String buffer, final int cursor, final List<CharSequence> candidates) {
              // buffer could be null
              checkNotNull(candidates);
  
              if (buffer == null) {
                  candidates.addAll(strings);
              }
              else {
                  for (String match : strings.tailSet(buffer.toLowerCase())) {
                      if (!match.startsWith(buffer.toLowerCase())) {
                          break;
                      }
  
                      candidates.add(match);
                  }
              }
  
              if (candidates.size() == 1) {
                  candidates.set(0, candidates.get(0) + " ");
              }
  
              return candidates.isEmpty() ? -1 : 0;
          }
  }