/**
    * Copyright 2011-2013 The Kuali 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.osedu.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.kuali.mobility.security.group.dao;
  
  import org.apache.log4j.Logger;
  import org.kuali.mobility.security.group.api.Group;
  import org.kuali.mobility.security.group.api.GroupDao;
  import org.springframework.stereotype.Repository;
  
  import javax.persistence.EntityManager;
  import javax.persistence.PersistenceContext;
  import javax.persistence.Query;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * @author Kuali Mobility Team (mobility.collab@kuali.org)
   */
  @Repository
  public class GroupDaoImpl implements GroupDao {
  	private static final Logger LOG = Logger.getLogger(GroupDaoImpl.class);
  
  	@PersistenceContext
  	private EntityManager entityManager;
  
  	private Map<String,Group> groupMap;
  
  	public void init() {
  		getGroups();
  	}
  
  	// This method can be used to refresh the cached group data.
  	@Override
  	public List<Group> getGroups() {
  		Query query = getEntityManager().createNamedQuery("Group.loadAllGroups");
  		List<Group> groups = query.getResultList();
  		if( groups != null && !groups.isEmpty() ) {
  			Map<String,Group> newGroupMap = new HashMap<String,Group>();
  			for( Group g : groups ) {
  				newGroupMap.put(g.getName(),g);
  			}
  			setGroupMap(newGroupMap);
  		}
  		return groups;
  	}
  
  	@Override
  	public Group getGroup(Long id) {
  		Query query = getEntityManager().createNamedQuery("Group.loadGroupById");
  		query.setParameter("id",id);
  		Group group = (Group)query.getSingleResult();
  		if( getGroupMap() != null ) {
  			getGroupMap().put(group.getName(),group);
  		} else {
  			getGroups();
  		}
  		return group;
  	}
  
  	@Override
  	public Group getGroup(String name) {
  		Group group = null;
  		if( getGroupMap() != null && getGroupMap().containsKey(name) ) {
  			group = getGroupMap().get(name);
  		}
  		return group;
  	}
  
  	@Override
  	public Long saveGroup(Group group) {
  		Long id;
  		if( null == group ) {
  			LOG.error("Attempting to save null group. Why is this happening?");
  			id = null;
  		} else {
  			if( null == group.getId() ) {
  				getEntityManager().persist(group);
  			} else {
  				getEntityManager().merge(group);
  			}
  			id = group.getId();
  		}
  		return id;
  	}
  
  	public EntityManager getEntityManager() {
 		return entityManager;
 	}
 
 	public void setEntityManager(EntityManager entityManager) {
 		this.entityManager = entityManager;
 	}
 
 	@Override
 	public Map<String, Group> getGroupMap() {
 		if( groupMap == null ) {
 			getGroups();
 		}
 		return groupMap;
 	}
 
 	@Override
 	public void setGroupMap(Map<String, Group> groupMap) {
 		this.groupMap = groupMap;
 	}
 }