/**

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You 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 org.apache.commons.cli2.commandline;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Set;

 import java.util.StringTokenizer;

 import java.util.prefs.BackingStoreException;

 import java.util.prefs.Preferences;

 import org.apache.commons.cli2.Option;

 import org.apache.commons.cli2.option.PropertyOption;

 /**

  * A CommandLine implementation using the Preferences API, useful when

  * constructing a complex DefaultingCommandLine

  *

  * This implementation uses the children of a single preference node to populate

  * the CommandLine.  Options are keyed from their preferred name and presence in

  * the Preferences object is taken as presence in the CommandLine.  Argument

  * values are taken from the Preference value and are optionally separated using

  * the separator char defined, at construction time.  Switch values can be

  * specified using a simple value of <code>true</code> or <code>false</code>;

  * obviously this means that Switches with Arguments are not supported by this

  * implementation.

  *

  * @see java.util.prefs.Preferences

  * @see org.apache.commons.cli2.commandline.DefaultingCommandLine

  * @see org.apache.commons.cli2.Option#getPreferredName()

  */

 public class PreferencesCommandLine extends CommandLineImpl {

     private static final char NUL = '\0';

     private final Preferences preferences;

     private final Option root;

     private final char separator;

     /**

      * Creates a new PreferencesCommandLine using the specified root Option and

      * Preferences node.  Argument values will be separated using the char 0.

      *

      * @param root the CommandLine's root Option

      * @param preferences the Preferences node to get values from

      */

     public PreferencesCommandLine(final Option root, final Preferences preferences){

         this(root,preferences,NUL);

     }

     /**

      * Creates a new PreferencesCommandLine using the specified root Option,

      * Preferences node and value separator.

      *

      * @param root the CommandLine's root Option

      * @param preferences the Preferences node to get values from

      * @param separator the character to split argument values

      */

     public PreferencesCommandLine(final Option root, final Preferences preferences, final char separator){

         this.root = root;

         this.preferences = preferences;

         this.separator = separator;

     }

     public boolean hasOption(Option option) {

         if(option==null){

             return false;

         }

         else{

             try {

                 return Arrays.asList(preferences.keys()).contains(option.getPreferredName());

             } catch (BackingStoreException e) {

                 return false;

             }

         }

     }

     public Option getOption(String trigger) {

         return root.findOption(trigger);

     }

     public List getValues(final Option option, final List defaultValues) {

         final String value = preferences.get(option.getPreferredName(),null);

         if(value==null){

             return defaultValues;

         }

         else if(separator>NUL){

             final List values = new ArrayList();

             final StringTokenizer tokens = new StringTokenizer(value,String.valueOf(separator));

             while(tokens.hasMoreTokens()){

                 values.add(tokens.nextToken());

             }

             return values;

         }

         else{

             return Collections.singletonList(value);

         }

     }

     public Boolean getSwitch(final Option option, final Boolean defaultValue) {

         final String value = preferences.get(option.getPreferredName(),null);

         if("true".equals(value)){

             return Boolean.TRUE;

         }

         else if("false".equals(value)){

             return Boolean.FALSE;

         }

         else{

             return defaultValue;

         }

     }

     public String getProperty(final String property) {

         return getProperty(new PropertyOption(), property);

     }

     public String getProperty(final Option option, final String property, final String defaultValue) {

         return preferences.get(property, defaultValue);

     }

         public Set getProperties(final Option option) {

         try {

             return new HashSet(Arrays.asList(preferences.keys()));

         } catch (BackingStoreException e) {

             return Collections.EMPTY_SET;

         }

     }

     public Set getProperties() {

         return getProperties(new PropertyOption());

     }

     public List getOptions() {

         try {

             final List options = new ArrayList();

             final Iterator keys = Arrays.asList(preferences.keys()).iterator();

             while (keys.hasNext()) {

                 final String trigger = (String) keys.next();

                 final Option option = root.findOption(trigger);

                 if (option != null) {

                     options.add(option);

                 }

             }

             return Collections.unmodifiableList(options);

         } catch (BackingStoreException e) {

             return Collections.EMPTY_LIST;

         }

     }

     public Set getOptionTriggers() {

         final Set triggers = new HashSet();

         final Iterator options = getOptions().iterator();

         while(options.hasNext()){

             final Option option = (Option)options.next();

             triggers.addAll(option.getTriggers());

         }

         return Collections.unmodifiableSet(triggers);

     }

 }