// Copyright 2008 Thiago H. de Paula Figueiredo
   //
   // Licensed under the Apache 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.apache.org/licenses/LICENSE-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 br.com.arsmachina.dao.hibernate.ioc;
  
  import java.beans.PropertyVetoException;
  
  import javax.sql.DataSource;
  
  import org.hibernate.SessionFactory;
  import org.hibernate.cfg.AnnotationConfiguration;
  import org.springframework.config.java.annotation.Bean;
  import org.springframework.config.java.annotation.Configuration;
  import org.springframework.config.java.annotation.ExternalValue;
  import org.springframework.config.java.annotation.Lazy;
  import org.springframework.config.java.annotation.ResourceBundles;
  import org.springframework.core.io.ClassPathResource;
  import org.springframework.orm.hibernate3.HibernateTransactionManager;
  import org.springframework.orm.hibernate3.LocalSessionFactoryBean;
  import org.springframework.transaction.PlatformTransactionManager;
  
  import com.mchange.v2.c3p0.ComboPooledDataSource;
  
  /**
   * Class that configures the persistence layer for Spring. Database info is read from a
   * <code>datasource.properties</code> file in the root of the classpath. Hibernate configuration
   * properties is read from a <code>hibernate.cfg.xml</code> file, also in the root of the
   * classpath.
   * 
   * @author Thiago H. de Paula Figueiredo
   */
  @Configuration(defaultLazy = Lazy.TRUE)
  @ResourceBundles( { "classpath:/datasource" })
  public class PersistenceConfiguration {
  
  	/**
  	 * Location, in the classpath, of the Hibernate configuration file.
  	 */
  	public static final String HIBERNATE_CONFIGURATION_FILE = "/hibernate.cfg.xml";
  
  	/**
  	 * Property used to define the database url.
  	 */
  	final public static String DATABASE_URL = "database.url";
  
  	/**
  	 * Property used to define the database JDBC driver class name.
  	 */
  	final public static String JDBC_DRIVER = "jdbc.driver";
  
  	/**
  	 * Property used to define the database user name.
  	 */
  	final public static String DATABASE_USERNAME = "database.username";
  
  	/**
  	 * Property used to define the database user password.
  	 */
  	final public static String DATABASE_PASSWORD = "database.password";
  
  	/**
  	 * Single constructor of this class.
  	 */
  	public PersistenceConfiguration() {
  	}
  
  	/**
  	 * Creates a {@link DataSource}.
  	 * 
  	 * @return a {@link DataSource}.
  	 */
  	@Bean
  	public DataSource dataSource() {
  
  		ComboPooledDataSource dataSource = new ComboPooledDataSource();
  
  		dataSource.setJdbcUrl(getDatabaseURL());
  		dataSource.setUser(getDatabaseUsername());
  		dataSource.setPassword(getDatabasePassword());
  
  		try {
  			dataSource.setDriverClass(getJDBCDriver());
  		}
  		catch (PropertyVetoException e) {
  			throw new RuntimeException(e);
  		}
  
  		return dataSource;
 
 	}
 
 	/**
 	 * Creates a {@link SessionFactory} that uses annotations and/or XML for mapping classes.
 	 * 
 	 * @return a {@link SessionFactory}.
 	 */
 	@Bean
 	public SessionFactory sessionFactory() {
 
 		LocalSessionFactoryBean factoryBean = new LocalSessionFactoryBean();
 		factoryBean.setConfigurationClass(AnnotationConfiguration.class);
 		factoryBean.setConfigLocation(new ClassPathResource(HIBERNATE_CONFIGURATION_FILE));
 
 		try {
 			factoryBean.afterPropertiesSet();
 		}
 		catch (Exception e) {
 			throw new RuntimeException(e);
 		}
 
 		return (SessionFactory) factoryBean.getObject();
 
 	}
 
 	/**
 	 * Creates the {@link PlatformTransactionManager} to be used by Spring.
 	 * 
 	 * @return a {@link HibernateTransactionManager}.
 	 */
 	@Bean
 	public PlatformTransactionManager transactionManager() {
 		return new HibernateTransactionManager(sessionFactory());
 	}
 
 //	@Bean(lazy = Lazy.FALSE)
 //	public OpenSessionInViewInterceptor openSessionInViewInterceptor() {
 //		
 //		final OpenSessionInViewInterceptor interceptor = new OpenSessionInViewInterceptor();
 //		interceptor.setSessionFactory(sessionFactory());
 //		interceptor.afterPropertiesSet();
 //		
 //		return interceptor;
 //		
 //	}
 
 	/**
 	 * Returns the JDBC driver class name.
 	 * 
 	 * @return a {@link String}.
 	 */
 	@ExternalValue(DATABASE_URL)
 	public String getDatabaseURL() {
 		return "value not set";
 	}
 
 	/**
 	 * Returns the JDBC driver class name.
 	 * 
 	 * @return a {@link String}.
 	 */
 	@ExternalValue(JDBC_DRIVER)
 	public String getJDBCDriver() {
 		return "value not set";
 	}
 
 	/**
 	 * Returns the database user name.
 	 * 
 	 * @return a {@link String}.
 	 */
 	@ExternalValue(DATABASE_USERNAME)
 	public String getDatabaseUsername() {
 		return "value not set";
 	}
 
 	/**
 	 * Returns the database user password.
 	 * 
 	 * @return a {@link String}.
 	 */
 	@ExternalValue(DATABASE_URL)
 	public String getDatabasePassword() {
 		return "value not set";
 	}
 
 }