/**
* @author Dimitry D'hondt
*
* This class is the base class for all 'Entity as value' wrappers.
* Being able to wrap an AbstractEntity as a valkue inside of another object
* allows us to define 'historically copied data' in our domain model.
*
* A good example is the UldRepairPart object. This object needs to maintain
* an historical copy of UldPart, UlrPartCost, UldRepairLaboutCost and GenericHour objects,
* so that exact details are known about the cost-calculation, even if in the future
* any of the above objects are updated. Clearly updating a UldPart with a new number of minutes
* for labour does NOT affect repairs, made in the past..
*
* The containing object may declare a property with type = "SomeConcreteEntityAsValueUserType" and
* then all property columns for the value of that property will get copied into the containing object,
* when an assignment is made on the usertype property.
*
* No changes need to be made to the classes being included.
*
* AbstractEntities, wrapped as values, are not mutable either, you replace them completely, or not at all..
*
* Wrapping an entity as value also removes any relationships it may have with other entities.
* All relationships will simply be null.
*
* For a concrete example see UldRepairPart.
*/
public abstract class AbstractEntityAsValueUserType implements UserType {

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

   /**
    * @see net.sf.hibernate.UserType#deepCopy(java.lang.Object)
    */
   public Object deepCopy(Object value) throws HibernateException {
      AbstractEntity abstractEntity = (AbstractEntity) value;
      return abstractEntity.clone();
   }

   /**
    * @see net.sf.hibernate.UserType#equals(java.lang.Object, java.lang.Object)
    */
   public boolean equals(Object x, Object y) throws HibernateException {
      AbstractEntity ae1 = (AbstractEntity) x;
      AbstractEntity ae2 = (AbstractEntity) y;
      return ae1.equals(ae2);
   }

   /**
    * @see net.sf.hibernate.UserType#isMutable()
    */
   public boolean isMutable() {
      return false;
   }

   /**
    * @see net.sf.hibernate.UserType#nullSafeGet(java.sql.ResultSet, java.lang.String[], java.lang.Object)
    */
   public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
      // TODO Auto-generated method stub
      return null;
   }

   /**
    * @see net.sf.hibernate.UserType#nullSafeSet(java.sql.PreparedStatement, java.lang.Object, int)
    */
   public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
      // TODO Auto-generated method stub

   }

   /**
    * @see net.sf.hibernate.UserType#returnedClass()
    */
   public Class returnedClass() {
      // TODO Auto-generated method stub
      return null;
   }

   /**
    * @see net.sf.hibernate.UserType#sqlTypes()
    */
   public int[] sqlTypes() {
      ClassMetadata metaData = getClassMetadata();
      int[] ret = null;
      
      String[] properties = metaData.getPropertyNames();
      SessionFactoryImpl sessionFactory = (SessionFactoryImpl) PersistencySupport.getSessionFactory();
      Type[] types = metaData.getPropertyTypes();
      List sqlTypes = new ArrayList();
      for (int i = 0; i < types.length; i++) {
         Type type = types[i];
         String property = properties[i];
//         if(type.sqlTypes(sessionFactory).length != 1) {
////            types.add(r(type.sqlTypes(sessionFactory)[0]));
//         } else {
//            log.debug("Property <" + property + "> not mapped for EntityAsValue wrapper.");
//         }
      }
      
//      ret = (int[]) sqlTypes.toArray(new int[0]);

      return ret;      
   }

   /**
    * Override this operation to configure the metadata
    * @return
    */
   private ClassMetadata getClassMetadata() {
      ClassMetadata ret = null;
      
      try {
         Class clazz = Class.forName("com.dhl.ncg.ums.model." + getEntityClassName());
         ret = PersistencySupport.getSessionFactory().getClassMetadata(clazz);
      } catch(ClassNotFoundException e) {
         String msg = "Configuration for UserType <" + this.getClass().getName() + "> specified an entity class <" + getEntityClassName() + "> that is not available in the VM.";
         log.error(msg,e);
         throw new InternalServerException(msg);
      } catch(HibernateException e) {
         String msg = "Configuration for UserType <" + this.getClass().getName() + "> specified an entity class <" + getEntityClassName() + "> unknown to Hibernate.";
         log.error(msg,e);
         throw new InternalServerException(msg);
      }
      
      return ret;
   }
   
   /**
    * Override this operation to configure the concrete class to wrap.
    * Don't specify the package ! com.dhl.ncg.ums.model. is prefixed automatically.
    * @return
    */
   protected abstract String getEntityClassName();
}