/*
    * Copyright 2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.admin.domain.model;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Set;
  import java.util.TreeSet;
  
  import com.google.common.collect.LinkedListMultimap;
  import com.google.common.collect.Multimap;
  
  import de.smartics.properties.api.core.domain.PropertyDescriptor;
  import de.smartics.properties.api.core.domain.PropertyDescriptorRegistry;
  import de.smartics.properties.api.core.domain.PropertyKey;
  
  /**
   * A set of properties descriptors.
   */
  public class PropertyDescriptors implements Serializable
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    /**
     * The registry of known descriptors.
     */
    private final PropertyDescriptorRegistry registry;
  
    /**
     * Helper to sort descriptors by property set name.
     */
    private final Multimap<String, PropertyDescriptor> sets = LinkedListMultimap
        .create();
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param registry the registry of known descriptors.
     */
    public PropertyDescriptors(final PropertyDescriptorRegistry registry)
    {
      this.registry = registry;
      init();
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    private void init()
    {
      final Set<Class<?>> propertySets = registry.getPropertySetTypes();
      for (final Class<?> propertySet : propertySets)
      {
        final List<? extends PropertyDescriptor> descriptors =
            registry.get(propertySet);
        if (descriptors.isEmpty())
        {
          continue;
        }
  
        final String propertySetName = getPropertySetName(descriptors);
  
        for (final PropertyDescriptor descriptor : descriptors)
        {
          sets.put(propertySetName, descriptor);
        }
     }
   }
 
   private String getPropertySetName(
       final List<? extends PropertyDescriptor> descriptors)
   {
     final PropertyDescriptor firstDescriptor = descriptors.get(0);
     final PropertyKey key = firstDescriptor.getKey();
     return key.getPropertySet();
   }
 
   // --- get&set --------------------------------------------------------------
 
   /**
    * Returns the registry of known descriptors.
    *
    * @return the registry of known descriptors.
    */
   public PropertyDescriptorRegistry getRegistry()
   {
     return registry;
   }
 
   /**
    * Returns the sorted collection of property keys.
    *
    * @return the sorted collection of property keys.
    */
   public Collection<String> getPropertyKeys()
   {
     return new TreeSet<String>(sets.keySet());
   }
 
   /**
    * Returns the sorted list of property descriptors.
    *
    * @param propertySet the set whose descritors are requested.
    * @return the sorted list of property descriptors.
    */
   public List<PropertyDescriptor> get(final String propertySet)
   {
     final List<PropertyDescriptor> descriptors =
         new ArrayList<PropertyDescriptor>(sets.get(propertySet));
     Collections.sort(descriptors, new Comparator<PropertyDescriptor>()
     {
       @Override
       public int compare(final PropertyDescriptor o1,
           final PropertyDescriptor o2)
       {
         return o1.getKey().compareTo(o2.getKey());
       }
     });
     return descriptors;
   }
 
   // --- business -------------------------------------------------------------
 
   // --- object basics --------------------------------------------------------
 
 }