/*
    * Copyright 2010-2013 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.testdoc.core.doc;
  
  import java.io.Serializable;
  
  import org.apache.commons.lang.ObjectUtils;
  
  /**
   * A key to attach to an entity for sorting.
   *
   * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
   * @version $Revision:591 $
   */
  public final class SortKey implements Serializable, Comparable<SortKey>
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * The class version identifier.
     * <p>
     * The value of this constant is {@value}.
     * </p>
     */
    private static final long serialVersionUID = 1L;
  
    // --- members --------------------------------------------------------------
  
    /**
     * The main key part of the sort key that controls the index key.
     *
     * @serial
     */
    private final String mainKey;
  
    /**
     * The key within the main key.
     *
     * @serial
     */
    private final String indexKey;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param mainKey the main key part of the sort key that controls the index
     *          key.
     * @param indexKey the key within the main key.
     */
    public SortKey(final String mainKey, final String indexKey)
    {
      this.mainKey = mainKey;
      this.indexKey = indexKey;
    }
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    /**
     * Returns the main key part of the sort key that controls the index key.
     *
     * @return the main key part of the sort key that controls the index key.
     */
    public String getMainKey()
    {
      return mainKey;
    }
  
    /**
     * Returns the key within the main key.
     *
     * @return the key within the main key.
     */
    public String getIndexKey()
    {
     return indexKey;
   }
 
   // --- business -------------------------------------------------------------
 
   /**
    * Checks if the sort key is condfigured or not.
    *
    * @return <code>false</code> if at least one key is set to a non-
    *         <code>null</code> value, <code>true</code> if both are
    *         <code>null</code>.
    */
   public boolean isDefault()
   {
     return mainKey == null && indexKey == null;
   }
 
   // --- object basics --------------------------------------------------------
 
   /**
    * Returns the hash code of the object.
    *
    * @return the hash code.
    */
   @Override
   public int hashCode()
   {
     int result = 17;
     result = 37 * result + ObjectUtils.hashCode(mainKey);
     result = 37 * result + ObjectUtils.hashCode(indexKey);
 
     return result;
   }
 
   /**
    * Returns <code>true</code> if the given object is semantically equal to the
    * given object, <code>false</code> otherwise.
    *
    * @param object the instance to compare to.
    * @return <code>true</code> if the given object is semantically equal to the
    *         given object, <code>false</code> otherwise.
    */
   @Override
   public boolean equals(final Object object)
   {
     if (this == object)
     {
       return true;
     }
     else if (object == null || getClass() != object.getClass())
     {
       return false;
     }
 
     final SortKey other = (SortKey) object;
 
     return (ObjectUtils.equals(mainKey, other.mainKey) && ObjectUtils.equals(
         indexKey, other.indexKey));
   }
 
   /**
    * {@inheritDoc}
    * <p>
    * Compares the main key before the index key. A value of <code>null</code> is
    * smaller than any other key.
    * </p>
    *
    * @see java.lang.Comparable#compareTo(java.lang.Object)
    */
   @Override
   public int compareTo(final SortKey other)
   {
     int compare = compare(mainKey, other.mainKey);
     if (compare == 0)
     {
       compare = compare(indexKey, other.indexKey);
     }
 
     return compare;
   }
 
   private static int compare(final String thisKey, final String otherKey)
   {
     if (thisKey != null && otherKey != null)
     {
       return thisKey.compareTo(otherKey);
     }
     else if (thisKey == null && otherKey != null)
     {
       return -1;
     }
     else if (otherKey == null && thisKey != null)
     {
       return 1;
     }
     else
     {
       return 0;
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see java.lang.Object#toString()
    */
   @Override
   public String toString()
   {
     final StringBuilder buffer = new StringBuilder(128);
     if (mainKey != null)
     {
       buffer.append(mainKey);
     }
     if (mainKey != null && indexKey != null)
     {
       buffer.append('/');
     }
     if (indexKey != null)
     {
       buffer.append(indexKey);
     }
     return buffer.toString();
   }
 }