/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  
  package ch.elca.el4j.services.persistence.generic.dto;
  
  import javax.persistence.Column;
  import javax.persistence.GeneratedValue;
  import javax.persistence.GenerationType;
  import javax.persistence.Id;
  import javax.persistence.MappedSuperclass;
  import javax.persistence.Transient;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import ch.elca.el4j.util.codingsupport.Reject;
  
  
  /**
   * This class is an abstract dto which uses an integer as key value and also
   * an integer for optimistic locking version controlling.
   *
   * @svnLink $Revision: 3873 $;$Date: 2009-08-04 13:59:45 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/core/src/main/java/ch/elca/el4j/services/persistence/generic/dto/AbstractIntKeyIntOptimisticLockingDto.java $
   *
   * @author Martin Zeltner (MZE)
   */
  @MappedSuperclass
  public abstract class AbstractIntKeyIntOptimisticLockingDto
  	extends AbstractIntOptimisticLockingDto
  	implements PrimaryKeyOptimisticLockingObject {
  	
  	/**
  	 * The logger.
  	 */
  	private static Logger s_logger = LoggerFactory.getLogger(AbstractIntKeyIntOptimisticLockingDto.class);
  
  	/**
  	 * Primary key.
  	 */
  	private int m_key;
  	
  	/**
  	 * Flag to indicate if the key is new.
  	 */
  	private boolean m_keyNew = true;
  	
  	/**
  	 * Has the hashCode value been leaked while being in transient state?
  	 */
  	private boolean m_transientHashCodeLeaked = false;
  
  	/**
  	 * @return Returns the key.
  	 */
  	@Id @GeneratedValue(strategy = GenerationType.AUTO,
  		generator = "keyid_generator")
  	@Column(name = "KEYID")
  	public int getKey() {
  		return m_key;
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 */
  	@Transient
  	public Object getKeyAsObject() {
  		return isKeyNew() ? null : Integer.valueOf(getKey());
  	}
  
  	/**
  	 * @param key The key to set.
  	 */
  	public void setKey(int key) {
  		m_key = key;
  		m_keyNew = false;
  	}
  	
  	/**
  	 * Convenience method to set the key. The given parameter must be an
  	 * <code>Number</code> otherwise it will be rejected.
  	 *
  	 * @param keyObject Is the key as object to set.
  	 */
  	public void setKey(Object keyObject) {
  		Reject.ifNull(keyObject);
 		Reject.ifNotAssignableTo(keyObject, Number.class);
 		int key = ((Number) keyObject).intValue();
 		setKey(key);
 	}
 	
 	/**
 	 * @return Returns <code>true</code> if the key has never be set by using
 	 *         method <code>setKey</code>.
 	 */
 	@Transient
 	public boolean isKeyNew() {
 		return m_keyNew;
 	}
 	
 	/**
 	 * {@inheritDoc}
 	 */
 	public int hashCode() {
 		if (m_keyNew) {
 			m_transientHashCodeLeaked = true;
 			return super.hashCode();
 		} else {
 			if (m_transientHashCodeLeaked) {
 				s_logger.error("hashCode() has be called once on transient state and once on persistent state  "
 					+ "of object '" + this.toString() + "' (" + getClass().toString() + "). "
 					+ "This can happen if you insert a transient object into a collection and persist them afterwards. "
 					+ "Save the objects before you insert them into a collection!");
 			}
 			return m_key;
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	public boolean equals(Object obj) {
 		if (this == obj) {
 			return true;
 		}
 		/* The following is a solution that works for hibernate lazy loading proxies.
 		if (getClass() != HibernateProxyHelper.getClassWithoutInitializingProxy(obj)) {
 			return false;
 		}*/
 		if (obj instanceof AbstractIntKeyIntOptimisticLockingDto) {
 			final AbstractIntKeyIntOptimisticLockingDto other = (AbstractIntKeyIntOptimisticLockingDto) obj;
 			if (!isKeyNew() && !other.isKeyNew()) {
 				return getKey() == other.getKey() && getClass() == other.getClass();
 			}
 		}
 		return false;
 	}
 
 	/**
 	 * Reset the key state to "new". This is required in some circumstances (offlining), otherwise
 	 * it should NOT be used.
 	 */
 	public void resetNew() {
 		m_keyNew = true;
 	}
 	
 	/**
 	 * {@inheritDoc}
 	 *
 	 * Does nothing, because primary key will be generated by database.
 	 */
 	public void useGeneratedKey() { }
 }