CourseManagerHibernateImpl.java

/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/edu-services/trunk/sections-service/sections-impl/standalone/src/java/org/sakaiproject/component/section/CourseManagerHibernateImpl.java $
 * $Id: CourseManagerHibernateImpl.java 105077 2012-02-24 22:54:29Z ottenhoff@longsight.com $
 ***********************************************************************************
 *
 * Copyright (c) 2005, 2006, 2008, 2009 The Sakai Foundation
 *
 * Licensed under the Educational Community License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.opensource.org/licenses/ECL-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **********************************************************************************/
package org.sakaiproject.component.section;

import java.sql.SQLException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.UUID;

import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.sakaiproject.id.api.IdManager;
import org.sakaiproject.section.api.CourseManager;
import org.sakaiproject.section.api.coursemanagement.Course;
import org.sakaiproject.section.api.coursemanagement.ParticipationRecord;
import org.sakaiproject.section.api.coursemanagement.User;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
 * Hibernate implementation of CourseManager.  Useful for loading data in standalone mode.
 * 
 * @author <a href="mailto:jholtzman@berkeley.edu">Josh Holtzman</a>
 *
 */
public class CourseManagerHibernateImpl extends HibernateDaoSupport
	implements CourseManager {

	private static final Log log = LogFactory.getLog(CourseManagerHibernateImpl.class);

	public Course createCourse(final String siteContext, final String title,
			final boolean selfRegAllowed, final boolean selfSwitchingAllowed,
			final boolean externallyManaged) {
		
		if(log.isDebugEnabled()) log.debug("Creating a new course offering named " + title);

		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				CourseImpl course = new CourseImpl();
        		course.setExternallyManaged(externallyManaged);
        		course.setSelfRegistrationAllowed(selfRegAllowed);
        		course.setSelfSwitchingAllowed(selfSwitchingAllowed);
        		course.setSiteContext(siteContext);
        		course.setTitle(title);
        		course.setUuid(UUID.randomUUID().toString());
        		session.save(course);
        		return course;
			};
		};

		return (Course)getHibernateTemplate().execute(hc);
	}

	public boolean courseExists(final String siteContext) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				Query q = session.getNamedQuery("loadCourseBySiteContext");
				q.setParameter("siteContext", siteContext);
				return q.uniqueResult();
			};
		};

		return getHibernateTemplate().execute(hc) != null;
	}

	public ParticipationRecord addInstructor(final User user, final Course course) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				InstructorRecordImpl pr = new InstructorRecordImpl(course, user);
				pr.setUuid(UUID.randomUUID().toString());
				session.save(pr);
				return pr;
			}
		};
		return (ParticipationRecord)getHibernateTemplate().execute(hc);
	}

	public ParticipationRecord addEnrollment(final User user, final Course course) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				EnrollmentRecordImpl enr = new EnrollmentRecordImpl(course, "enrolled", user);
				enr.setUuid(UUID.randomUUID().toString());
				session.save(enr);
				return enr;
			}
		};
		return (ParticipationRecord)getHibernateTemplate().execute(hc);
	}

	public ParticipationRecord addTA(final User user, final Course course) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				TeachingAssistantRecordImpl ta = new TeachingAssistantRecordImpl(course, user);
				ta.setUuid(UUID.randomUUID().toString());
				session.save(ta);
				return ta;
			}
		};
		return (ParticipationRecord)getHibernateTemplate().execute(hc);
	}
	
	public void removeCourseMembership(final String userUid, final Course course) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				Query q = session.getNamedQuery("loadSiteParticipation");
				q.setParameter("siteContext", course.getSiteContext());
				q.setParameter("userUid", userUid);
				Object result = q.uniqueResult();
				if(result != null) {
					session.delete(result);
					if(log.isInfoEnabled()) log.info("Site membership for " + userUid + " in course " +
							course + " has been deleted");
				} else {
					if(log.isInfoEnabled()) log.info("Could not find membership for " +
							userUid + " in course " + course);
				}
				return null;
			}
		};
		getHibernateTemplate().execute(hc);
		
		// Make sure we remove any orphaned section memberships
		removeOrphans(course.getSiteContext());
		
	}
	
	/**
	 * @inheritDoc
	 */
	public void removeOrphans(final String siteContext) {
		final Set userUids = getSiteMemberIds(siteContext);
		if(userUids == null || userUids.isEmpty()) {
			return;
		}
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException, SQLException {
				Query q = session.getNamedQuery("findOrphanedSectionMemberships");
				q.setParameter("siteContext", siteContext);
				q.setParameterList("userUids", userUids);
				int deleted = 0;
				for(Iterator iter = q.iterate(); iter.hasNext(); deleted++) {
					session.delete(iter.next());
				}
				if(log.isInfoEnabled()) log.info(deleted + " section memberships deleted");
				return null;
			}
		};
		getHibernateTemplate().execute(hc);
	}

	/**
	 * Gets only the user IDs of the site members
	 * 
	 * @param siteContext
	 * @return
	 */
	private Set getSiteMemberIds(final String siteContext) {
		HibernateCallback hc = new HibernateCallback() {
			public Object doInHibernate(Session session) throws HibernateException ,SQLException {
				Query q = session.getNamedQuery("findSiteMemberUserUids");
				q.setParameter("siteContext", siteContext);
				return new HashSet(q.list());
			};
		};

		return (Set)getHibernateTemplate().execute(hc);
	}
}