/*
    * Copyright 2007 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.opensource.org/licenses/ecl2.php
    *
   * 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.rice.kns.dao.jdbc;
  
  import javax.persistence.EntityManager;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.ojb.broker.PBKey;
  import org.apache.ojb.broker.PersistenceBroker;
  import org.kuali.rice.core.config.ConfigurationException;
  import org.kuali.rice.core.util.OrmUtils;
  import org.kuali.rice.kns.bo.BusinessObject;
  import org.kuali.rice.kns.bo.DocumentHeader;
  import org.kuali.rice.kns.bo.ModuleConfiguration;
  import org.kuali.rice.kns.dao.SequenceAccessorDao;
  import org.kuali.rice.kns.service.KNSServiceLocator;
  import org.kuali.rice.kns.service.KualiModuleService;
  import org.kuali.rice.kns.service.ModuleService;
  import org.springmodules.orm.ojb.OjbFactoryUtils;
  
  /**
   * This class uses the KualiDBPlatform to get the next number from a given sequence.
   */
  public class SequenceAccessorDaoJdbc extends PlatformAwareDaoBaseJdbc implements SequenceAccessorDao {
  	private KualiModuleService kualiModuleService;
  	
  	private Long nextAvailableSequenceNumber(String sequenceName, 
  			Class<? extends BusinessObject> clazz) {
  		
          ModuleService moduleService = getKualiModuleService().getResponsibleModuleService(clazz);
          if ( moduleService == null )
          	throw new ConfigurationException("moduleService is null");
          	        	
          ModuleConfiguration moduleConfig = moduleService.getModuleConfiguration();
          if ( moduleConfig == null )
          	throw new ConfigurationException("moduleConfiguration is null");
          
      	String dataSourceName = moduleConfig.getDataSourceName();
      	EntityManager entityManager = moduleConfig.getEntityManager();
  
          if ( StringUtils.isEmpty(dataSourceName) ) 
          	throw new ConfigurationException("dataSourceName is not set");       	
          	
      	if ( OrmUtils.isJpaAnnotated(clazz) && OrmUtils.isJpaEnabled() ) {
              if ( entityManager != null ) 
              	return getDbPlatform().getNextValSQL(sequenceName, entityManager);
              else
              	throw new ConfigurationException("EntityManager is null");
          } 
      	else {
      		PBKey key = new PBKey(dataSourceName);
      		PersistenceBroker broker = OjbFactoryUtils.getPersistenceBroker(key, false);
      		if ( broker != null )
      			return getDbPlatform().getNextValSQL(sequenceName, broker);
      		else
      			throw new ConfigurationException("PersistenceBroker is null");            			
          }
  	}
  	
  	public Long getNextAvailableSequenceNumber(String sequenceName, 
  			Class<? extends BusinessObject> clazz) {
  		
  		// There are situations where a module hasn't been configured with
  		// a dataSource.  In these cases, this method would have previously
  		// thrown an error.  Instead, we've opted to factor out the code,
  		// catch any configuration-related exceptions, and if one occurs,
  		// attempt to use the dataSource associated with KNS. -- tbradford
  		
  		try {
  			return nextAvailableSequenceNumber(sequenceName, clazz);
  		}
  		catch ( ConfigurationException e  ) {
  	    	// Use DocumentHeader to get the dataSourceName associated with KNS			
  			return nextAvailableSequenceNumber(sequenceName, DocumentHeader.class);			
  		}
  	}
  	
      /**
       * @see org.kuali.rice.kns.dao.SequenceAccessorDao#getNextAvailableSequenceNumber(java.lang.String)
       */
      public Long getNextAvailableSequenceNumber(String sequenceName) {
      	// Use DocumentHeader to get the dataSourceName associated with KNS
      	return nextAvailableSequenceNumber(sequenceName, DocumentHeader.class);
      }
      
      private KualiModuleService getKualiModuleService() {
         if ( kualiModuleService == null ) 
             kualiModuleService = KNSServiceLocator.getKualiModuleService();
         return kualiModuleService;
     }
 }