// $HeadURL$
// $Id$
//
// Copyright © 2006, 2010, 2011, 2012 by the President and Fellows of Harvard College.
//
// Screensaver is an open-source project developed by the ICCB-L and NSRB labs
// at Harvard Medical School. This software is distributed under the terms of
// the GNU General Public License.

package edu.harvard.med.screensaver.ui.arch.util;

import java.util.Collection;

import edu.harvard.med.screensaver.db.GenericEntityDAO;
import edu.harvard.med.screensaver.model.AbstractEntity;

import org.apache.log4j.Logger;

/**
 * A select-one UI component for a model entity.
 * Entities in this UI selection must already be persisted.
 */
public class UISelectOneEntityBean<E extends AbstractEntity> extends UISelectOneBean<E>
{

  // static members

  private static Logger log = Logger.getLogger(UISelectOneEntityBean.class);


  // instance data members

  private GenericEntityDAO _dao;


  // public constructors and methods

  public UISelectOneEntityBean(Collection<E> entities, GenericEntityDAO dao)
  {
    this(entities, null, false, dao);
  }

  public UISelectOneEntityBean(Collection<E> entities, E defaultSelection, GenericEntityDAO dao)
  {
    this(entities, defaultSelection, false, dao);
  }

  public UISelectOneEntityBean(Collection<E> entities, E defaultSelection, boolean isEmptyValueAllowed, GenericEntityDAO dao)
  {
    super(entities, defaultSelection, isEmptyValueAllowed);
    _dao = dao;
  }

  @SuppressWarnings("unchecked")
  @Override
  public E getSelection()
  {
    AbstractEntity entity = super.getSelection();
    if (entity == null) {
      return null;
    }
    // reload entity, to ensure it is Hibernate-managed (if this method is
    // invoked within a Hibernate session)
    return (E) _dao.findEntityById(entity.getEntityClass(), entity.getEntityId());
  }

  protected String makeKey(E e)
  {
    return e.getEntityId().toString();
  }
}