/*

  * Copyright 2012-2013 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.api.core.domain;

 import java.io.Serializable;

 import org.apache.commons.lang.ObjectUtils;

 import de.smartics.util.lang.Arg;

 import de.smartics.util.lang.BlankArgumentException;

 /**

  * Defines a property key information. A property key uniquely identifies a

  * property. It contains a name that is scoped by the name of the property set.

  * That is, the name is only unique within its property set. To create the fully

  * qualified property key, call {@link #toString()}.

  */

 public final class PropertyKey implements Serializable, Comparable<PropertyKey>

 {

   // ********************************* Fields *********************************

   // --- constants ------------------------------------------------------------

   /**

    * The class version identifier.

    */

   private static final long serialVersionUID = 1L;

   // --- members --------------------------------------------------------------

   /**

    * The name of the set the property belongs to. This is the scope within the

    * {@link #getName() name} is unique. It may be <code>null</code> (which

    * indicates that the scope is global), but is must not be blank.

    *

    * @serial

    */

   private final String propertySet;

   /**

    * The name of the property.

    * <p>

    * This value must not be blank.

    * </p>

    *

    * @serial

    */

   private final String name;

   // ****************************** Initializer *******************************

   // ****************************** Constructors ******************************

   /**

    * Convenience constructor without a property set name.

    *

    * @param name the name of the property.

    * @throws IllegalArgumentException if {@code name} is blank.

    */

   public PropertyKey(final String name) throws IllegalArgumentException

   {

     this(null, name);

   }

   /**

    * Default constructor.

    *

    * @param propertySet the name of the set the property belongs to.

    * @param name the name of the property.

    * @throws IllegalArgumentException if {@code propertySet} is blank but not

    *           <code>null</code> or if {@code name} is blank.

    */

   public PropertyKey(final String propertySet, final String name)

     throws IllegalArgumentException

   {

     this.propertySet = Arg.checkNotBlankExceptNull("propertySet", propertySet);

     this.name = Arg.checkNotBlank("name", name);

   }

   // ****************************** Inner Classes *****************************

   // ********************************* Methods ********************************

   // --- init -----------------------------------------------------------------

   /**

    * Creates an instance for the given qualified name.

    * <p>

    * The qualified name consists of two part that are separated by a 'at' (

    * <code>@</code>) sign. The first part is the name of the property set, the

    * second part the name of the property.

    * </p>

    * {@example my-set@my.property.name}

    * <p>

    * The last 'at' sign is significant for the separation. That is, the property

    * set name may contain any number of 'at' signs. An 'at' sign at the end of

    * the qualified name is ignored.

    * </p>

    *

    * @param qualifiedName a name optionally prefixed with a property set name

    *          separated by a 'at' (<code>@</code>) sign.

    * @return the created instance.

    */

   public static PropertyKey create(final String qualifiedName)

   {

     return create(qualifiedName, '@');

   }

   /**

    * Creates an instance for the given qualified name.

    *

    * @param qualifiedName a name optionally prefixed with a property set name

    *          separated by the last occurrence (excluding the very end) of the

    *          {@code separator}.

    * @param separator the separator to use if for some reason the default is not

    *          appropriate.

    * @return the created instance.

    * @throws BlankArgumentException if {@code qualifiedName} is blank.

    */

   public static PropertyKey create(final String qualifiedName,

       final char separator) throws BlankArgumentException

   {

     Arg.checkNotBlank("qualifiedName", qualifiedName);

     final int dotIndex = qualifiedName.lastIndexOf(separator);

     if (dotIndex > 0 && dotIndex < qualifiedName.length() - 1)

     {

       final String propertySetName = qualifiedName.substring(0, dotIndex);

       final String name = qualifiedName.substring(dotIndex + 1);

       return new PropertyKey(propertySetName, name);

     }

     else

     {

       return new PropertyKey(null, qualifiedName);

     }

   }

   /**

    * Creates an instance for the given set and name.

    *

    * @param propertySet the name of the set the property belongs to.

    * @param name the name of the property.

    * @return the created instance.

    * @throws IllegalArgumentException if {@code propertySet} is blank but not

    *           <code>null</code> or if {@code name} is blank.

    */

   public static PropertyKey create(final String propertySet, final String name)

     throws IllegalArgumentException

   {

     return new PropertyKey(propertySet, name);

   }

   // --- get&set --------------------------------------------------------------

   /**

    * Returns the name of the set the property belongs to. This is the scope

    * within the {@link #getName() name} is unique. It may be <code>null</code>

    * (which indicates that the scope is global), but is must not be blank.

    *

    * @return the name of the set the property belongs to.

    */

   public String getPropertySet()

   {

     return propertySet;

   }

   /**

    * Returns the name of the property.

    * <p>

    * This value must not be <code>null</code>.

    * </p>

    *

    * @return the name of the property.

    */

   public String getName()

   {

     return name;

   }

   // --- business -------------------------------------------------------------

   // --- object basics --------------------------------------------------------

   @Override

   public int compareTo(final PropertyKey o)

   {

     int result = ObjectUtils.compare(propertySet, o.propertySet);

     if (result == 0)

     {

       result = name.compareTo(o.name);

     }

     return result;

   }

   @Override

   public int hashCode()

   {

     int result = 17;

     result = 37 * result + ObjectUtils.hashCode(propertySet);

     result = 37 * result + name.hashCode();

     return result;

   }

   @Override

   public boolean equals(final Object object)

   {

     if (this == object)

     {

       return true;

     }

     else if (object == null || getClass() != object.getClass())

     {

       return false;

     }

     final PropertyKey other = (PropertyKey) object;

     return ObjectUtils.equals(propertySet, other.propertySet)

            && name.equals(other.name);

   }

   /**

    * Returns the string representation of the object.

    *

    * @return the string representation of the object.

    */

   @Override

   public String toString()

   {

     final StringBuilder buffer = new StringBuilder();

     if (propertySet != null)

     {

       buffer.append(propertySet).append('.');

     }

     buffer.append(name);

     return buffer.toString();

   }

 }