package test;

import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import java.util.logging.Logger;

import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.EntityListeners;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Persistence;
import javax.persistence.PreUpdate;
import javax.persistence.Temporal;

import junit.framework.TestCase;

import org.hibernate.annotations.GenericGenerator;

public class EntityListenerTest extends TestCase
{
   @Entity
   @EntityListeners(OrderListener.class)
   static class Order
   {
      @Basic
      String customerName;

      @OneToMany(mappedBy = "order", cascade = {CascadeType.ALL}, fetch = FetchType.LAZY)
      @org.hibernate.annotations.Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
      @org.hibernate.annotations.OnDelete(action = org.hibernate.annotations.OnDeleteAction.CASCADE)
      Set<OrderItem> items = new HashSet<OrderItem>();

      @Id
      @GeneratedValue(generator = "system-uuid")
      @GenericGenerator(name = "system-uuid", strategy = "uuid")
      String id;

      @Temporal
      Date lastModified;
   }

   @Entity
   static class OrderItem
   {
      @Basic
      int amount;

      @ManyToOne(optional = false, fetch = FetchType.LAZY)
      Order order;
      @Id
      @GeneratedValue(generator = "system-uuid")
      @GenericGenerator(name = "system-uuid", strategy = "uuid")
      String id;
   }

   public static class OrderListener
   {
      static boolean onPreUpdateCalled = false;

      @PreUpdate
      public void onPreUpdate(Order theOrder)
      {
         theOrder.lastModified = new Date();
         onPreUpdateCalled = true;
      }
   }

   private final static Logger LOG = Logger.getLogger(EntityListenerTest.class.getName());

   private final EntityManagerFactory emf = Persistence.createEntityManagerFactory("manager1");

   public Order createAnOrder()
   {
      // create and persist an order with one item
      Order theOrder = new Order();
      theOrder.customerName = "acme";
      OrderItem anItem = new OrderItem();
      anItem.order = theOrder;
      anItem.amount = 1;
      theOrder.items.add(anItem);
      persist(theOrder);

      return theOrder;
   }

   private void merge(Object e) throws RuntimeException
   {
      EntityManager em = emf.createEntityManager();
      EntityTransaction tx = null;
      try
      {
         tx = em.getTransaction();
         tx.begin();
         em.merge(e);
         tx.commit();
      }
      catch (RuntimeException ex)
      {
         if (tx != null && tx.isActive()) tx.rollback();
         throw ex;
      }
      finally
      {
         em.close();
      }
   }

   private void persist(Object e) throws RuntimeException
   {
      EntityManager em = emf.createEntityManager();
      EntityTransaction tx = null;
      try
      {
         tx = em.getTransaction();
         tx.begin();
         em.persist(e);
         tx.commit();
      }
      catch (RuntimeException ex)
      {
         if (tx != null && tx.isActive()) tx.rollback();
         throw ex;
      }
      finally
      {
         em.close();
      }
   }

   public void testMergeOrderUmodified()
   {
      Order theOrder = createAnOrder();

      OrderListener.onPreUpdateCalled = false;

      // merge the unmodified order
      merge(theOrder);

      if (OrderListener.onPreUpdateCalled == false)
      {
         LOG.warning("OrderListener.onPreUpdate was not called.");
         fail();
      }
      else
      {
         LOG.info("OrderListener.onPreUpdate was called.");
      }
   }

   public void testMergeOrderWithModifiedField()
   {
      Order theOrder = createAnOrder();

      OrderListener.onPreUpdateCalled = false;

      // modify the order and merge
      theOrder.customerName = "john doe";
      merge(theOrder);
      assertTrue(OrderListener.onPreUpdateCalled);
   }

   public void testMergeOrderWithModifiedItem()
   {
      Order theOrder = createAnOrder();

      OrderListener.onPreUpdateCalled = false;

      // modify an item and merge the order
      OrderItem theItem = theOrder.items.iterator().next();
      theItem.amount = 10;
      merge(theOrder);

      if (OrderListener.onPreUpdateCalled == false)
      {
         LOG.warning("OrderListener.onPreUpdate was not called.");
         fail();
      }
      else
      {
         LOG.info("OrderListener.onPreUpdate was called.");
      }
   }
}