/*

  * 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.core.ojb;

 import java.sql.Connection;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import javax.sql.DataSource;

 import org.apache.ojb.broker.accesslayer.ConnectionFactoryNotPooledImpl;

 import org.apache.ojb.broker.accesslayer.LookupException;

 import org.apache.ojb.broker.metadata.JdbcConnectionDescriptor;

 import org.springframework.beans.factory.BeanFactory;

 import org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy;

 public class RiceDataSourceConnectionFactory extends ConnectionFactoryNotPooledImpl {

         /**

          * BeanFactories to retrieve DataSource beans from.

          */

         private static List<BeanFactory> beanFactories = new ArrayList<BeanFactory>();

         public static void addBeanFactory(BeanFactory beanFactory) {

                 beanFactories.add(beanFactory);

         }

         /**

          * Map that holds already retrieved DataSources,

          * with JCD alias Strings as keys and DataSources as values.

          */

         private Map<String, DataSource> dataSources = new HashMap<String, DataSource>();

         public RiceDataSourceConnectionFactory() {

                 if (beanFactories.isEmpty()) {

                         throw new IllegalStateException("No BeanFactories found for configuration - must specify RiceOjbConfigurer as a Spring bean.");

                 }

         }

         public Connection lookupConnection(JdbcConnectionDescriptor jcd) throws LookupException {

                 try {

                         DataSource dataSource = null;

                         synchronized (this.dataSources) {

                                 dataSource = this.dataSources.get(jcd.getJcdAlias());

                                 if (dataSource == null) {

                                         dataSource = getDataSource(jcd.getJcdAlias());

                                         this.dataSources.put(jcd.getJcdAlias(), dataSource);

                                 }

                         }

                         return dataSource.getConnection();

                 }

                 catch (Exception ex) {

                         throw new LookupException("Could not obtain connection from data source", ex);

                 }

         }

         /**

          * Return the DataSource to use for the given JCD alias.

          * <p>This implementation fetches looks for a bean with the

          * JCD alias name in the provided Spring BeanFactory.

          * @param jcdAlias the JCD alias to retrieve a DataSource for

          * @return the DataSource to use

          */

         protected DataSource getDataSource(String jcdAlias) throws LookupException {

                 DataSource dataSource = null;

                 for (BeanFactory beanFactory : beanFactories) {

                         if (beanFactory.containsBean(jcdAlias)) {

                                 dataSource = (DataSource) beanFactory.getBean(jcdAlias, DataSource.class);

                                 break;

                         }

                 }

                 if (dataSource == null) {

                         throw new LookupException("Could not lookup datasource with alias " + jcdAlias);

                 } else if (dataSource instanceof TransactionAwareDataSourceProxy) {

                         return dataSource;

                 } else {

                         return new TransactionAwareDataSourceProxy(dataSource);

                 }

         }

 }