package com.melloware.jukes.db;
   
   import java.util.Collection;
   import java.util.Iterator;
   import java.util.List;
   
   import org.apache.commons.logging.Log;
   import org.apache.commons.logging.LogFactory;
   import org.hibernate.Criteria;
  import org.hibernate.LockMode;
  import org.hibernate.Query;
  import org.hibernate.criterion.Example;
  import org.hibernate.criterion.Order;
  
  import com.melloware.jukes.db.orm.AbstractJukesObject;
  import com.melloware.jukes.exception.InfrastructureException;
  
  /**
   * Static methods for access data using Hibernate.
   * <p>
   * Copyright (c) 1999-2007 Melloware, Inc. <http://www.melloware.com>
   * @author Emil A. Lefkof III <info@melloware.com>
   * @version 4.0
   */
  public final class HibernateDao {
     private static final Log LOG = LogFactory.getLog(HibernateDao.class);
  
     /**
      * Private No Instantiation.
      */
     private HibernateDao() {
        super();
     }
  
     /**
      * Attaches a clean instance of an object to a session.
      * <p>
      * @param instance the instance to attach
      */
     public static void attachClean(final AbstractJukesObject instance) {
        LOG.debug("attaching clean instance");
        try {
           HibernateUtil.getSession().lock(instance, LockMode.NONE);
           LOG.debug("attach successful");
        } catch (RuntimeException re) {
           LOG.error(re.getMessage(), re);
           throw new InfrastructureException(re);
        }
     }
  
     /**
      * Attaches a dirty instance of an object to a session.
      * <p>
      * @param instance the instance to attach
      */
     public static void attachDirty(final AbstractJukesObject instance) {
        LOG.debug("attaching dirty instance");
        try {
           HibernateUtil.getSession().saveOrUpdate(instance);
           LOG.debug("attach successful");
        } catch (RuntimeException re) {
           LOG.error(re.getMessage(), re);
           throw new InfrastructureException(re);
        }
     }
  
     /**
      * Gets a count using a HQL Query.
      * <p>
      * @param aHQLQuery the query to run
      * @return the count
      */
     public static int count(final String aHQLQuery) {
        LOG.debug("Count : " + aHQLQuery);
        try {
           final int count = ((Integer) HibernateUtil.getSession().createQuery("select count(id) from " + aHQLQuery)
                    .uniqueResult()).intValue();
           return count;
        } catch (RuntimeException re) {
           LOG.error(re.getMessage(), re);
           throw new InfrastructureException(re);
        }
     }
  
     /**
      * Gets a sum of a long type column
      * <p>
      * @param aClass the class to sum up
      * @param aLongField the field to sum up
      * @return the sum
      */
     public static long sum(final Class aClass, final String aLongField) {
        LOG.debug("Sum : " + aClass.getName());
        try {
           final long sum = ((Long) HibernateUtil.getSession().createQuery(
                    "select sum(" + aLongField + ") from " + aClass.getName()).uniqueResult()).longValue();
           return sum;
        } catch (RuntimeException re) {
           LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Counts ALL of a certain domain class.
     * <p>
     * @param aClass the class to count
     * @return the count
     */
    public static long countAll(final Class aClass) {
       LOG.debug("Count All " + aClass.getName());
       try {
          final long count = ((Long) HibernateUtil.getSession().createQuery("select count(id) from " + aClass.getName())
                   .uniqueResult()).longValue();
          return count;
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Creates a criteria for the Class.
     * <p>
     * @param aClass the class to create a criteria for.
     * @return the Criteria object
     */
    public static Criteria createCriteria(final Class aClass) {
       return HibernateUtil.getSession().createCriteria(aClass);
    }
 
    /**
     * Delete a persistent object from the store.
     * <p>
     * @param persistentInstance the object to delete
     */
    public static void delete(final AbstractJukesObject persistentInstance) {
       LOG.debug("deleting instance");
       try {
          HibernateUtil.getSession().delete(persistentInstance);
          LOG.debug("delete successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Deletes a whole collection from the store.
     * <p>
     * @param aCollection the collection to delete
     */
    public static void deleteAll(final Collection aCollection) {
       LOG.debug("deleting collection");
       if (aCollection == null) {
          return;
       }
       try {
          final Iterator iterator = aCollection.iterator();
          while (iterator.hasNext()) {
             final AbstractJukesObject element = (AbstractJukesObject) iterator.next();
             iterator.remove();
             HibernateDao.delete(element);
          }
 
          HibernateUtil.getSession().flush();
          LOG.debug("deleting collection successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Find all of an object with a specified sort order.
     * <p>
     * @param aClass the class to find
     * @param aSortColumn the sort column to use
     * @return a List of all objects found
     */
    public static List findAll(final Class aClass, final String aSortColumn) {
       if (LOG.isDebugEnabled()) {
          LOG.debug("geting ALL " + aClass.getName());
       }
 
       List items;
       try {
          final Criteria criteria = createCriteria(aClass);
          criteria.addOrder(Order.asc(aSortColumn));
          items = criteria.list();
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
       return items;
    }
 
    /**
     * Finds persistent objects from the store by Criteria provided.
     * <p>
     * @param criteria the criteria object to use
     * @return a List of all objects found
     */
    public static List findByCriteria(final Criteria criteria) {
       LOG.debug("finding instance by criteria");
       try {
          final List results = criteria.list();
          LOG.debug("find by criteria successful, result size: " + results.size());
          return results;
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Finds persistent objects from the store by Example provided.
     * <p>
     * @param instance the persistent object to use an as example
     * @return a List of all objects found
     */
    public static List findByExample(final AbstractJukesObject instance) {
       LOG.debug("finding instance by example");
       try {
          final Example example = Example.create(instance);
          final List results = HibernateUtil.getSession().createCriteria(instance.getClass()).add(example).list();
          LOG.debug("find by example successful, result size: " + results.size());
          return results;
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Find by primary key.
     * <p>
     * @param aClass the Class to look for
     * @param id the primary key
     * @return a persisten object if found by primary key
     */
    public static AbstractJukesObject findById(final Class aClass, final long id) {
       return findById(aClass, Long.valueOf(id));
    }
 
    /**
     * Find by primary key.
     * <p>
     * @param aClass the Class to look for
     * @param id the primary key
     * @return a persisten object if found by primary key
     */
    public static AbstractJukesObject findById(final Class aClass, final Long id) {
       LOG.debug("getting instance with id: " + id);
       try {
          final AbstractJukesObject instance = (AbstractJukesObject) HibernateUtil.getSession().get(aClass, id);
          if (instance == null) {
             LOG.debug("get successful, no instance found");
          } else {
             LOG.debug("get successful, instance found");
          }
          return instance;
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Find all of an object with a specified HQL Query.
     * <p>
     * @param aHQLQuery the query to execute
     * @return a List of all objects found
     */
    public static List findByQuery(final String aHQLQuery) {
       if (LOG.isDebugEnabled()) {
          LOG.debug("findByQuery " + aHQLQuery);
       }
 
       List items;
       try {
          items = HibernateUtil.getSession().createQuery(aHQLQuery).list();
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
       return items;
    }
 
    /**
     * Find all of an object with a specified HQL Query.
     * <p>
     * @param aHQLQuery the query to execute
     * @param aMaxResults the maximum results to return
     * @return a List of all objects found
     */
    public static List findByQuery(final String aHQLQuery, final int aMaxResults) {
       if (LOG.isDebugEnabled()) {
          LOG.debug("findByQuery " + aHQLQuery);
       }
 
       List items;
       try {
          final Query query = HibernateUtil.getSession().createQuery(aHQLQuery);
          query.setMaxResults(aMaxResults);
          items = query.list();
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
       return items;
    }
 
    /**
     * Finds a single object using the aHQLQuery.
     * <p>
     * @param aHQLQuery the query to execute
     * @return a List of all objects found
     */
    public static AbstractJukesObject findUniqueByQuery(final String aHQLQuery) {
       if (LOG.isDebugEnabled()) {
          LOG.debug("findUniqueByQuery " + aHQLQuery);
       }
 
       AbstractJukesObject result = null;
       try {
          result = (AbstractJukesObject) HibernateUtil.getSession().createQuery(aHQLQuery).uniqueResult();
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
       return result;
    }
 
    /**
     * Finds a single persistent object from the store by Example provided.
     * <p>
     * @param instance the persistent object to use an as example
     * @return the object found if one
     */
    public static AbstractJukesObject findUniqueByExample(final AbstractJukesObject instance) {
       LOG.debug("finding unique instance by example");
       AbstractJukesObject result = null;
       try {
          final Example example = Example.create(instance);
          result = (AbstractJukesObject) HibernateUtil.getSession().createCriteria(instance.getClass()).add(example)
                   .uniqueResult();
          LOG.debug("find by unique example successful ");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
       return result;
    }
 
    /**
     * Merges an instance of a persistable object into a session and returns the
     * merged object.
     * <p>
     * @param detachedInstance the instance to attach
     */
    public static AbstractJukesObject merge(final AbstractJukesObject detachedInstance) {
       LOG.debug("merging Album instance");
       try {
          final AbstractJukesObject result = (AbstractJukesObject) HibernateUtil.getSession().merge(detachedInstance);
          LOG.debug("merge successful");
          return result;
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Persist an object to the store.
     * <p>
     * @param transientInstance the object to persist
     */
    public static void persist(final AbstractJukesObject transientInstance) {
       LOG.debug("persisting instance");
       try {
          HibernateUtil.getSession().persist(transientInstance);
          LOG.debug("persist successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Persist an object to the store.
     * <p>
     * @param transientInstance the object to persist
     */
    public static void saveOrUpdate(final AbstractJukesObject transientInstance) {
       LOG.debug("saveOrUpdate instance");
       try {
          HibernateUtil.getSession().saveOrUpdate(transientInstance);
          LOG.debug("saveOrUpdate successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
    /**
     * Refreshes an object from the database. If you think data may be stale and
     * need updating.
     * <p>
     * @param transientInstance the object to refresh
     */
    public static void refresh(final AbstractJukesObject transientInstance) {
       LOG.debug("refreshing instance");
       try {
          HibernateUtil.getSession().refresh(transientInstance);
          LOG.debug("refreshing successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
    
    public static void refreshAll(final Collection aCollection) {
       LOG.debug("refreshing collection");
       if (aCollection == null) {
          return;
       }
       try {
          final Iterator iterator = aCollection.iterator();
          while (iterator.hasNext()) {
             final AbstractJukesObject element = (AbstractJukesObject) iterator.next();
             HibernateDao.refresh(element);
          }
          LOG.debug("refreshing collection successful");
       } catch (RuntimeException re) {
          LOG.error(re.getMessage(), re);
          throw new InfrastructureException(re);
       }
    }
 
 }