/**
    * 
    */
   package ar.com.jiji.kaya.spring;
   
   import java.util.Iterator;
   import java.util.Map;
   import java.util.Set;
   
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.hibernate.HibernateException;
  import org.hibernate.SessionFactory;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.FatalBeanException;
  import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
  import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  
  import ar.com.jiji.kaya.KayaException;
  import ar.com.jiji.kaya.KayaRuntimeException;
  import ar.com.jiji.kaya.reflect.MethodNames;
  import ar.com.jiji.kaya.reflect.ReflectionException;
  import ar.com.jiji.kaya.reflect.ReflectionService;
  import ar.com.jiji.kaya.utils.ValidateUtils;
  
  /**
   * Trata de descubrir implementaciones de daos a partir de las clases mapeadas
   * en Hibernate y setearlos a los objetos que se desea (si existen los setters).
   * 
   * TODO: escribir mas docs
   * 
   * @author lparra
   * @version $Revision$ $Date$
   */
  public class DaoAutoWirer implements BeanFactoryPostProcessor {
  	private static final Log log = LogFactory.getLog(DaoAutoWirer.class);
  
  	private SessionFactory sessionFactory;
  
  	private String daoPackage = "dao";
  
  	private String daoImplPackage = "dao.hib";
  
  	private String daoSuffix = "Dao";
  
  	private String daoImplSuffix = "DaoImpl";
  
  	private boolean failOnMissingDaoSetter = false;
  
  	private boolean failOnMissingDaoImpl = false;
  
  	private Set objects;
  
  	private DaoInstantiator daoInstantiator;
  
  	public DaoAutoWirer() {
  		setDaoInstantiator(new SimpleDaoInstantiator());
  	}
  
  	public boolean isFailOnMissingDaoImpl() {
  		return failOnMissingDaoImpl;
  	}
  
  	public void setFailOnMissingDaoImpl(boolean failOnMissingDaoImpl) {
  		this.failOnMissingDaoImpl = failOnMissingDaoImpl;
  	}
  
  	public String getDaoImplSuffix() {
  		return daoImplSuffix;
  	}
  
  	public void setDaoImplSuffix(String daoImplSuffix) {
  		this.daoImplSuffix = daoImplSuffix;
  	}
  
  	public String getDaoSuffix() {
  		return daoSuffix;
  	}
  
  	public void setDaoSuffix(String daoSuffix) {
  		this.daoSuffix = daoSuffix;
  	}
  
  	public String getDaoPackage() {
  		return daoPackage;
  	}
  
  	public void setDaoPackage(String daoPackage) {
  		this.daoPackage = daoPackage;
  	}
  
  	public SessionFactory getSessionFactory() {
  		return sessionFactory;
  	}
  
  	public void setSessionFactory(SessionFactory sessionFactory) {
  		this.sessionFactory = sessionFactory;
  	}
  
 	protected void populateObjects(Set objects) throws BeansException {
 		ValidateUtils.notNull(objects);
 
 		if (getSessionFactory() == null)
 			throw new FatalBeanException("No session factory set");
 
 		Map metadata;
 		try {
 			metadata = this.sessionFactory.getAllClassMetadata();
 		} catch (HibernateException e) {
 			throw new FatalBeanException("Collecting metadata", e);
 		}
 		for (Iterator i = metadata.keySet().iterator(); i.hasNext();) {
 			String className = (String) i.next();
 			String modelPkg;
 			String modelName;
 			String daoPkg, daoImplPkg;
 			int pos;
 
 			pos = className.lastIndexOf('.');
 			if (pos == -1) {
 				modelPkg = "";
 				modelName = className;
 			} else {
 				modelPkg = className.substring(0, pos);
 				modelName = className.substring(pos + 1);
 			}
 
 			log.info("searching dao for mapped class " + className);
 
 			pos = modelPkg.lastIndexOf('.');
 			if (pos == -1) {
 				log.info("default package for " + modelName
 						+ ", searching dao there.");
 				daoImplPkg = daoPkg = "";
 			} else {
 				daoImplPkg = modelPkg.substring(0, pos + 1)
 						+ getDaoImplPackage() + ".";
 				daoPkg = modelPkg.substring(0, pos + 1) + getDaoPackage() + ".";
 			}
 
 			String clazzImpl = daoImplPkg + modelName + getDaoImplSuffix();
 			String classInterface = daoPkg + modelName + getDaoSuffix();
 
 			Object dao = null;
 			try {
 				dao = newDaoInstance(clazzImpl, classInterface);
 				log.info("found dao " + clazzImpl + " for " + className);
 			} catch (KayaException e) {
 				throw new KayaRuntimeException(e);
 			} catch (ClassNotFoundException e) {
 				if (isFailOnMissingDaoImpl()) {
 					throw new KayaRuntimeException(e);
 				}
 				log.info("dao " + clazzImpl + " not found for " + className);
 			}
 
 			if (dao != null) {
 				try {
 					initDao(dao);
 					for (Object o : objects)
 						setDao(o, dao, classInterface);
 				} catch (KayaException e) {
 					throw new FatalBeanException("", e);
 				} catch (NoSuchMethodException e) {
 					if (isFailOnMissingDaoSetter()) {
 						// TODO crear alguna excepcion
 						throw new RuntimeException(e);
 					}
 					log
 							.info("object doesn't have setter for "
 									+ classInterface);
 				}
 			}
 		}
 	}
 
 	private void setDao(Object obj, Object dao, String interfaceName)
 			throws KayaException, NoSuchMethodException {
 		try {
 			Class interfaceClazz = Class.forName(interfaceName);
 			ReflectionService.invoke(MethodNames.getDaoMutator(interfaceClazz),
 					interfaceClazz, obj, dao);
 			log.info("set " + interfaceName);
 		} catch (SecurityException e) {
 			throw new KayaException(e);
 		} catch (ReflectionException e) {
 			if (e.getCause() instanceof NoSuchMethodException) {
 				if (isFailOnMissingDaoSetter())
 					throw new KayaException(e);
 			} else
 				throw new KayaException(e);
 		} catch (ClassNotFoundException e) {
 			throw new KayaException(e);
 		}
 	}
 
 	private void initDao(Object dao) throws KayaException,
 			NoSuchMethodException {
 		setSessionFactory(dao);
 	}
 
 	private void setSessionFactory(Object dao) throws KayaException,
 			NoSuchMethodException {
 		// TODO: tal vez spring tenga algo ya para esto
 		try {
 			ReflectionService.invoke(MethodNames.getMutator("sessionFactory"),
 					SessionFactory.class, dao, getSessionFactory());
 		} catch (SecurityException e) {
 			throw new KayaException(e);
 		} catch (IllegalArgumentException e) {
 			throw new KayaException(e);
 		} catch (ReflectionException e) {
 			throw new KayaException(e);
 		}
 	}
 
 	private Object newDaoInstance(String clazzImpl, String classInterface)
 			throws KayaException, ClassNotFoundException {
 		try {
 			return getDaoInstantiator().instantiate(clazzImpl, classInterface);
 		} catch (InstantiationException e) {
 			throw new KayaException(e);
 		} catch (IllegalAccessException e) {
 			throw new KayaException(e);
 		}
 	}
 
 	public String getDaoImplPackage() {
 		return daoImplPackage;
 	}
 
 	public void setDaoImplPackage(String daoImplPackage) {
 		this.daoImplPackage = daoImplPackage;
 	}
 
 	public boolean isFailOnMissingDaoSetter() {
 		return failOnMissingDaoSetter;
 	}
 
 	public void setFailOnMissingDaoSetter(boolean failOnMissingDaoSetter) {
 		this.failOnMissingDaoSetter = failOnMissingDaoSetter;
 	}
 
 	public void postProcessBeanFactory(
 			ConfigurableListableBeanFactory beanFactory) throws BeansException {
 		populateObjects(getObjects());
 	}
 
 	public Set getObjects() {
 		return objects;
 	}
 
 	public void setObjects(Set objects) {
 		this.objects = objects;
 	}
 
 	public DaoInstantiator getDaoInstantiator() {
 		return daoInstantiator;
 	}
 
 	public void setDaoInstantiator(DaoInstantiator daoInstantiator) {
 		this.daoInstantiator = daoInstantiator;
 	}
 
 }