/*

  * 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 java.util.Collection;

 import org.apache.commons.lang.ObjectUtils;

 import org.apache.commons.lang.StringUtils;

 import de.smartics.util.lang.Arg;

 import de.smartics.util.lang.NullArgumentException;

 /**

  * Provides information about the type of a property.

  */

 public final class PropertyType implements Serializable

 {

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

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

   /**

    * The class version identifier.

    */

   private static final long serialVersionUID = 1L;

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

   /**

    * The Java type of the property.

    *

    * @serial

    */

   private final Class<?> type;

   /**

    * The Java type of the elements of the property if the {@link #getType()

    * type} is a collection type. The value is derived from the value specified

    * as {@link de.smartics.properties.api.core.annotations.PropertyElementType}.

    *

    * @serial

    */

   private final Class<?> elementType;

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

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

   /**

    * Convenience constructor for non-collection types.

    *

    * @param type the Java type of the property.

    * @throws NullArgumentException if {@code type} is <code>null</code>.

    */

   public PropertyType(final Class<?> type) throws NullArgumentException

   {

     this(type, null);

   }

   /**

    * Default constructor.

    *

    * @param type the Java type of the property.

    * @param elementType the Java type of the elements of the property if the

    *          {@link #getType() type} is a collection type.

    * @throws NullArgumentException if {@code type} is <code>null</code>.

    */

   public PropertyType(final Class<?> type, final Class<?> elementType)

     throws NullArgumentException

   {

     this.type = Arg.checkNotNull("type", type);

     this.elementType = calcDefaultElementType(type, elementType);

   }

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

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

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

   /**

    * Calculates the default element type if none is specified but {@code type}

    * is a collection.

    *

    * @see de.smartics.properties.api.core.annotations.PropertyElementType

    */

   private static Class<?> calcDefaultElementType(final Class<?> type,

       final Class<?> elementType)

   {

     if (elementType != null)

     {

       return elementType;

     }

     return (Collection.class.isAssignableFrom(type) ? String.class : null);

   }

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

   /**

    * Returns the Java type of the property.

    *

    * @return the Java type of the property.

    */

   public Class<?> getType()

   {

     return type;

   }

   /**

    * Returns the Java type of the elements of the property if the

    * {@link #getType() type} is a collection type. The value is derived from the

    * value specified as

    * {@link de.smartics.properties.api.core.annotations.PropertyElementType}.

    *

    * @return the Java type of the elements of the property if the

    *         {@link #getType() type} is a collection type.

    */

   public Class<?> getElementType()

   {

     return elementType;

   }

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

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

   /**

    * Returns the hash code of the object.

    *

    * @return the hash code.

    */

   @Override

   public int hashCode()

   {

     return type.hashCode();

   }

   /**

    * 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 PropertyType other = (PropertyType) object;

     return (type.equals(other.type) && ObjectUtils.equals(elementType,

         other.elementType));

   }

   /**

    * Returns the simple (no package part) name of the type.

    *

    * @return the simple name of the type.

    */

   public String toSimpleString()

   {

     return type.getSimpleName()

            + (elementType != null ? '<' + elementType.getSimpleName() + '>'

                : StringUtils.EMPTY);

   }

   /**

    * Returns the name of the type.

    *

    * @return the name of the type.

    */

   @Override

   public String toString()

   {

     return type.getName()

            + (elementType != null ? '<' + elementType.getName() + '>'

                : StringUtils.EMPTY);

   }

 }