package com.hi.dao;
import java.sql.SQLException;
import javax.annotation.Resource;
import org.hibernate.CacheMode;
import org.hibernate.FlushMode;
import org.hibernate.Query;
import org.hibernate.ScrollMode;
import org.hibernate.ScrollableResults;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.Ignore;
import org.junit.Test;
import static org.junit.Assert.*;
import org.junit.runner.RunWith;
import org.springframework.orm.hibernate3.SessionFactoryUtils;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.hi.dataimprover.core.BdsContact;
import com.hi.dataimprover.core.BdsException;
import com.hi.dataimprover.installer.DatabaseCreator;

/**
* This test generates a table with 1 million rows and tries to
* iterate through it using a scrollable Hibernate query.
*
*/
@RunWith(value=SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/configuration-test.xml","/dao.xml","/jndi-test.xml","/dao-installer.xml"})
public class TestLargeDataSet {

   // fixtures
   @Resource
   DatabaseCreator databaseCreator;

   @Resource
   private Dao dao;

   @Test
   public void testDummy() {
      assertTrue("This dummy test should always succeed.",true);
   }
   
   @Test
   public void testIterateThroughLargeDataset() throws SQLException, BdsException {
      databaseCreator.create();
      generateManyRecords();
      iterateThroughManyRecords();
   }

   private void generateManyRecords() throws BdsException {
      for(int i=0 ; i<10000 ; i++) {
         BdsContact c = new BdsContact();
         dao.saveOrUpdate(c);
         if(i % 10000==0) {
            System.out.println("Inserted "+i+" items.");
         }
      }
   }
   
   private void iterateThroughManyRecords() {
      String query = "from BdsContact";
      SessionFactory sessionFactory = dao.getSessionFactory();
      Session session = SessionFactoryUtils.getSession(sessionFactory,true);
      session.setFlushMode(FlushMode.MANUAL);
      session.setCacheMode(CacheMode.IGNORE);
      Query q = session.createQuery(query);
      ScrollableResults scrollable = q.scroll(ScrollMode.FORWARD_ONLY);
      long cursorCounter = 0;
      while(scrollable.next()) {
         BdsContact c = (BdsContact) scrollable.get(0);
         cursorCounter++;
         if(cursorCounter % 1000==0) {
            session.flush();
            session.clear();
         }
         if(cursorCounter % 10000==0) {
            System.out.println("Retrieved "+cursorCounter+" items.");
         }
      }
      session.close();
      System.out.println("Finished. Retrieved "+cursorCounter+" items");
   }
}