EDIT

/**

 *

 */

package eu.etaxonomy.cdm.persistence.dao.initializer;

import java.beans.PropertyDescriptor;

import java.io.Serializable;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.lang.reflect.ParameterizedType;

import java.lang.reflect.Type;

import java.lang.reflect.TypeVariable;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import org.apache.commons.beanutils.PropertyUtils;

import org.apache.log4j.Logger;

import org.hibernate.Hibernate;

import org.hibernate.HibernateException;

import org.hibernate.Query;

import org.hibernate.collection.internal.AbstractPersistentCollection;

import org.hibernate.collection.internal.PersistentMap;

import org.hibernate.envers.entities.mapper.relation.lazy.proxy.CollectionProxy;

import org.hibernate.envers.entities.mapper.relation.lazy.proxy.MapProxy;

import org.hibernate.envers.entities.mapper.relation.lazy.proxy.SortedMapProxy;

import org.hibernate.proxy.HibernateProxy;

import org.springframework.beans.factory.annotation.Autowired;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.cdm.persistence.dao.common.ICdmGenericDao;

import eu.etaxonomy.cdm.persistence.dao.hibernate.HibernateBeanInitializer;

/**

 * For now this is a test if we can improve performance for bean initializing

 * @author a.mueller

 * @date 2013-10-25

 *

 */

public class AdvancedBeanInitializer extends HibernateBeanInitializer {

    public static final Logger logger = Logger.getLogger(AdvancedBeanInitializer.class);

    @Autowired

    ICdmGenericDao genericDao;

    @Override

    public void initialize(Object bean, List<String> propertyPaths) {

        List<Object> beanList = new ArrayList<Object>(1);

        beanList.add(bean);

        initializeAll(beanList, propertyPaths);

    }

    //TODO optimize algorithm ..

    @Override

    public <C extends Collection<?>> C initializeAll(C beanList,  List<String> propertyPaths) {

        if (beanList == null || beanList.isEmpty()){

            return beanList;

        }

        //autoinitialize

        for (Object bean : beanList){

            autoinitializeBean(bean);

        }

        if(propertyPaths == null){

            return beanList;

        }

        //new

         BeanInitNode rootPath = BeanInitNode.createInitTree(propertyPaths);

        if (logger.isTraceEnabled()){logger.trace(rootPath.toStringTree());}

        if(logger.isDebugEnabled()){ logger.debug(">> starting to initialize beanlist ; class(e.g.):" + beanList.iterator().next().getClass().getSimpleName());}

        rootPath.addBeans(beanList);

        initializeNodeRecursive(rootPath);

        //old - keep for safety (this may help to initialize those beans that are not yet correctly initialized by the AdvancedBeanInitializer

        if(logger.isTraceEnabled()){logger.trace("Start old initalizer ... ");};

        for (Object bean :beanList){

            Collections.sort(propertyPaths);

            for(String propPath : propertyPaths){

//		            initializePropertyPath(bean, propPath);

            }

        }

        if(logger.isDebugEnabled()){ logger.debug("   Completed initialization of beanlist "); }

        return beanList;

    }

    //new

    private void initializeNodeRecursive(BeanInitNode rootPath) {

        initializeNode(rootPath);

        for (BeanInitNode childPath : rootPath.getChildrenList()){

            initializeNodeRecursive(childPath);

        }

        rootPath.resetBeans();

    }

    /**

     * Initializes the given single <code>propPath</code> String.

     *

     * @param bean

     * @param propPath

     */

    private void initializeNode(BeanInitNode node) {

        if(logger.isDebugEnabled()){logger.debug(" processing " + node.toString());}

        if (node.isRoot()){

            return;

        }else if (node.isWildcard()){

            initializeNodeWildcard(node);

        } else {

            initializeNodeNoWildcard(node);

        }

    }

    // if propPath only contains a wildcard (* or $)

    // => do a batch initialization of *toOne or *toMany relations

    private void initializeNodeWildcard(BeanInitNode node) {

//			boolean initToMany = node.isToManyWildcard();

        Map<Class<?>, Set<Object>> parentBeans = node.getParentBeans();

        for (Class<?> clazz : parentBeans.keySet()){

            //new

            for (Object bean : parentBeans.get(clazz)){

                if(Collection.class.isAssignableFrom(bean.getClass())){

//				        old: initializeAllEntries((Collection<?>)bean, true, initToMany);  //TODO is this a possible case at all??

                    throw new RuntimeException("Collection no longer expected in 'initializeNodeWildcard()'. Therefore an exception is thrown.");

                } else if(Map.class.isAssignableFrom(bean.getClass())) {

//				        old: initializeAllEntries(((Map<?,?>)bean).values(), true, initToMany);  ////TODO is this a possible case at all??

                    throw new RuntimeException("Map no longer expected in 'initializeNodeWildcard()'. Therefore an exception is thrown.");

                } else{

                    prepareBeanWildcardForBulkLoad(node, bean);

                }

            }

            //end new

//		    	initializeNodeWildcardOld(initToMany, beans, clazz);  //if switched on move bulkLoadLazies up

        }

        //

        bulkLoadLazies(node);

    }

    /**

     * @param initToMany

     * @param beans

     * @param clazz

     */

    private void initializeNodeWildcardOld(boolean initToMany,

            Map<Class<?>, Set<Object>> beans, Class<?> clazz) {

        for (Object bean : beans.get(clazz)){

            if(Collection.class.isAssignableFrom(bean.getClass())){

                initializeAllEntries((Collection<?>)bean, true, initToMany);

            } else if(Map.class.isAssignableFrom(bean.getClass())) {

                initializeAllEntries(((Map<?,?>)bean).values(), true, initToMany);

            } else{

                initializeBean(bean, true, initToMany);

            }

        }

    }

    private void prepareBeanWildcardForBulkLoad(BeanInitNode node, Object bean){

        if(logger.isTraceEnabled()){logger.trace(">> prepare bulk wildcard initialization of a bean of type " + bean.getClass().getSimpleName()); }

        Set<Class<?>> restrictions = new HashSet<Class<?>>();

        restrictions.add(CdmBase.class);

        if(node.isToManyWildcard()){

            restrictions.add(Collection.class);

        }

        Set<PropertyDescriptor> props = getProperties(bean, restrictions);

        for(PropertyDescriptor propertyDescriptor : props){

            try {

                String property = propertyDescriptor.getName();

//                  invokeInitialization(bean, propertyDescriptor);

                Object propertyValue = PropertyUtils.getProperty( bean, property);

                preparePropertyValueForBulkLoadOrStore(node, bean, property,  propertyValue );

            } catch (IllegalAccessException e) {

                logger.error("Illegal access on property " + propertyDescriptor.getName());

            } catch (InvocationTargetException e) {

                logger.info("Cannot invoke property " + propertyDescriptor.getName() + " not found");

            } catch (NoSuchMethodException e) {

                logger.info("Property " + propertyDescriptor.getName() + " not found");

            }

        }

        if(logger.isTraceEnabled()){logger.trace(" completed bulk wildcard initialization of a bean");}

    }

   // propPath contains either a single field or a nested path

    // split next path token off and keep the remaining as nestedPath

    private void initializeNodeNoWildcard(BeanInitNode node) {

        String property = node.getPath();

        int pos;

        // is the property indexed?

        Integer index = null;

        if((pos = property.indexOf('[')) > 0){

            String indexString = property.substring(pos + 1, property.indexOf(']'));

            index = Integer.valueOf(indexString);

            property = property.substring(0, pos);

        }

        //Class targetClass = HibernateProxyHelper.getClassWithoutInitializingProxy(bean); // used for debugging

        for (Class<?> parentClazz : node.getParentBeans().keySet()){

            if (logger.isTraceEnabled()){logger.trace(" invoke initialization on "+ node.toString()+ " beans of class " + parentClazz.getSimpleName() + " ... ");}

            Set<Object> parentBeans = node.getParentBeans().get(parentClazz);

            if (index != null){

                logger.warn("Property path index not yet implemented for 'new'");

            }

            //new

            for (Object parentBean : parentBeans){

                preparePropertyForSingleBean(node, property, parentClazz, parentBean);

            }//end for

            //end new

//			 initializeNodeNoWildcardOld(node, property, index, parentBeans);  //move bulkLoadLazies up again, if uncomment this line

        } //end for

        bulkLoadLazies(node);

    }

    /**

     * Prepare a single property of a non-collection bean. Collections are handled elsewhere.

     */

    private void preparePropertyForSingleBean(BeanInitNode node, String property, Class<?> parentClazz, Object bean) {

        String propertyName = mapFieldToPropertyName(property, bean.getClass().getSimpleName());

        try{

            Object propertyValue = PropertyUtils.getProperty(bean, propertyName);

            preparePropertyValueForBulkLoadOrStore(node, bean, property, propertyValue);

        } catch (IllegalAccessException e) {

            String message = "Illegal access on property " + property;

            logger.error(message);

            throw new RuntimeException(message, e);

        } catch (InvocationTargetException e) {

            String message = "Cannot invoke property " + property + " not found";

            logger.error(message);

            throw new RuntimeException(message, e);

        } catch (NoSuchMethodException e) {

            String message = "Property " + propertyName + " not found for class " + parentClazz;

            logger.error(message);

            throw new RuntimeException(message, e);

        }

    }

//    /**

//     * @param node

//     * @param property

//     * @param index

//     * @param parentBeans

//     * @throws IllegalAccessException

//     * @throws InvocationTargetException

//     * @throws NoSuchMethodException

//     */

//    private void initializeNodeNoWildcardOld(BeanInitNode node,

//                String property,

//                Integer index,

//                Set<Object> parentBeans)

//            throws IllegalAccessException, InvocationTargetException, NoSuchMethodException

//    {

//        for (Object bean : parentBeans){

//

//            PropertyDescriptor propertyDescriptor = PropertyUtils.getPropertyDescriptor(bean, property);

//            if (logger.isTraceEnabled()){logger.trace("   unwrap " + node.toStringNoWildcard() + " ... ");}

//            // [1] initialize the bean named by property

//            Object unwrappedPropertyBean = invokeInitialization(bean, propertyDescriptor);

//            if (logger.isTraceEnabled()){logger.trace("   unwrap " + node.toStringNoWildcard() + " - DONE ");}

//

//

//            // [2]

//            // handle property

//            if(unwrappedPropertyBean != null ){

//                initializeNodeSinglePropertyOld(node, property, index, bean, unwrappedPropertyBean);

//            }

//        }

//    }

    /**

     * @param node

     * @param propertyValue

     * @param parentBean

     * @param param

     */

    private void preparePropertyValueForBulkLoadOrStore(BeanInitNode node,

            Object parentBean,

            String param,

            Object propertyValue)

    {

        BeanInitNode sibling = node.getSibling(param);

        if (propertyValue instanceof AbstractPersistentCollection ){

            //collections

            if (!node.hasWildcardToManySibling()){  //if wildcard sibling exists the lazies are already prepared there

                AbstractPersistentCollection collection = (AbstractPersistentCollection)propertyValue;

                if (collection.wasInitialized()){

                    storeInitializedCollection(collection, node, param);

                }else{

//						Class<?> parentClass = parentBean.getClass();

//						int parentId = ((CdmBase)parentBean).getId();

                    if (sibling != null){

                        sibling.putLazyCollection(collection);

                    }else{

                        node.putLazyCollection(collection);

                    }

                }

            }

        } else if (propertyValue instanceof CollectionProxy

                || propertyValue instanceof MapProxy<?, ?>

                || propertyValue instanceof SortedMapProxy<?, ?>){

            //hibernate envers collections

            //TODO check if other code works with audited data at all as we use HQL queries

            if (!node.hasWildcardToManySibling()){  //if wildcard sibling exists the lazies are already prepared there

                Collection<?> collection = (Collection<?>)propertyValue;

                //TODO it is difficult to find out if an envers collection is initiallized

                //but possiblie via reflection. If the "delegate" parameter is null it is not yet initialized.

                //However, as we do not know if envers initialization works at all together with the AdvancedBeanInitializer

                //we initialize each collection immediately here by calling size()

                collection.size();  //initialize

                storeInitializedEnversCollection(collection, node, param);

            }

        }else{

            //singles

            if (!node.hasWildcardToOneSibling()){  //if wildcard exists the lazies are already prepared there

                if (! Hibernate.isInitialized(propertyValue)){

                    if (propertyValue instanceof HibernateProxy){

                        Serializable id = ((HibernateProxy)propertyValue).getHibernateLazyInitializer().getIdentifier();

                        Class<?> persistedClass = ((HibernateProxy)propertyValue).getHibernateLazyInitializer().getPersistentClass();

                        if (sibling != null){

                            sibling.putLazyBean(persistedClass, id);

                        }else{

                            node.putLazyBean(persistedClass, id);

                        }

                    }else{

                        logger.warn("Lazy value is not of type HibernateProxy. This is not yet handled.");

                    }

                }else if (propertyValue == null){

                    // do nothing

                }else{

                    if (propertyValue instanceof HibernateProxy){  //TODO remove hibernate dependency

                        propertyValue = initializeInstance(propertyValue);

                    }

                    autoinitializeBean(propertyValue);

                    node.addBean(propertyValue);

                }

            }

        }

    }

    private void autoinitializeBean(Object bean) {

        invokePropertyAutoInitializers(bean);

    }

    private void autoinitializeBean(CdmBase bean, AutoInit autoInit) {

        for(AutoPropertyInitializer<CdmBase> init : autoInit.initlializers) {

            init.initialize(bean);

        }

    }

	private void storeInitializedCollection(AbstractPersistentCollection persistedCollection,

			BeanInitNode node, String param) {

	    Collection<?> collection;

		if (persistedCollection  instanceof Collection) {

			collection = (Collection<?>) persistedCollection;

		}else if (persistedCollection instanceof Map) {

			collection = ((Map<?,?>)persistedCollection).values();

		}else{

			throw new RuntimeException ("Non Map and non Collection cas not handled in storeInitializedCollection()");

		}

		for (Object value : collection){

			preparePropertyValueForBulkLoadOrStore(node, null, param, value);

		}

	}

	/**

	 * @see #storeInitializedCollection(AbstractPersistentCollection, BeanInitNode, String)alizedCollection

	 */

	private void storeInitializedEnversCollection(Collection<?> enversCollection,

            BeanInitNode node, String param) {

	    if (enversCollection instanceof CollectionProxy

                || enversCollection instanceof MapProxy<?, ?>

                || enversCollection instanceof SortedMapProxy<?, ?>){

	        Collection<?> collection;

	        if (enversCollection instanceof MapProxy

	                || enversCollection instanceof SortedMapProxy<?, ?>) {

	            collection = ((Map<?,?>)enversCollection).values();

	        }else if (enversCollection instanceof CollectionProxy) {

	            collection = enversCollection;

	        }else{

	            throw new RuntimeException ("Non MapProxy and non CollectionProxy case not handled in storeInitializedEnversCollection()");

	        }

	        for (Object value : collection){

	            preparePropertyValueForBulkLoadOrStore(node, null, param, value);

	        }

	    }

    }

	private void bulkLoadLazies(BeanInitNode node) {

		if (logger.isTraceEnabled()){logger.trace("bulk load " +  node);}

		//beans

		for (Class<?> clazz : node.getLazyBeans().keySet()){

			Set<Serializable> idSet = node.getLazyBeans().get(clazz);

			if (idSet != null && ! idSet.isEmpty()){

				if (logger.isTraceEnabled()){logger.trace("bulk load beans of class " +  clazz.getSimpleName());}

				//TODO use entity name

				String hql = " SELECT c FROM %s as c %s WHERE c.id IN (:idSet) ";

				AutoInit autoInit = addAutoinitFetchLoading(clazz, "c");

                hql = String.format(hql, clazz.getSimpleName(), autoInit.leftJoinFetch);

				if (logger.isTraceEnabled()){logger.trace(hql);}

				Query query = genericDao.getHqlQuery(hql);

				query.setParameterList("idSet", idSet);

				List<Object> list = query.list();

				if (logger.isTraceEnabled()){logger.trace("initialize bulk loaded beans of class " +  clazz.getSimpleName());}

				for (Object object : list){

					if (object instanceof HibernateProxy){  //TODO remove hibernate dependency

						object = initializeInstance(object);

					}

					autoinitializeBean((CdmBase)object, autoInit);

					node.addBean(object);

				}

				if (logger.isTraceEnabled()){logger.trace("bulk load - DONE");}

			}

		}

		node.resetLazyBeans();

		//collections

		for (Class<?> ownerClazz : node.getLazyCollections().keySet()){

			Map<String, Set<Serializable>> lazyParams = node.getLazyCollections().get(ownerClazz);

			for (String param : lazyParams.keySet()){

				Set<Serializable> idSet = lazyParams.get(param);

				if (idSet != null && ! idSet.isEmpty()){

					if (logger.isTraceEnabled()){logger.trace("bulk load " + node + " collections ; ownerClass=" +  ownerClazz.getSimpleName() + " ; param = " + param);}

					Type collectionEntitiyType = null;

					PropertyDescriptor[] descriptors = PropertyUtils.getPropertyDescriptors(ownerClazz);

					for(PropertyDescriptor d : descriptors) {

					    if(d.getName().equals(param)) {

					        Method readMethod = d.getReadMethod();

                            ParameterizedType pt = (ParameterizedType) readMethod.getGenericReturnType();

                            Type[] actualTypeArguments = pt.getActualTypeArguments();

                            if(actualTypeArguments.length == 2) {

                                // this must be a map of <Language, String> (aka LanguageString) there is no other case like this in the cdm

                                // in case of Maps the returned Collection will be the Collection of the values, so collectionEntitiyType is the

                                // second typeArgument

                                collectionEntitiyType = actualTypeArguments[1];

                            } else {

                                collectionEntitiyType = actualTypeArguments[0];

                            }

                            if(collectionEntitiyType instanceof TypeVariable) {

                                collectionEntitiyType = ((TypeVariable)collectionEntitiyType).getBounds()[0];

                            }

					    }

					}

					//TODO use entity name ??

					//get from repository

					List<Object[]> list;

					String hql = "SELECT oc " +

							" FROM %s as oc LEFT JOIN FETCH oc.%s as col %s" +

							" WHERE oc.id IN (:idSet) ";

					AutoInit autoInit = addAutoinitFetchLoading((Class)collectionEntitiyType, "col");

                    hql = String.format(hql, ownerClazz.getSimpleName(), param,

					        autoInit.leftJoinFetch);

					try {

						if (logger.isTraceEnabled()){logger.trace(hql);}

						Query query = genericDao.getHqlQuery(hql);

						query.setParameterList("idSet", idSet);

						list = query.list();

						if (logger.isTraceEnabled()){logger.trace("size of retrieved list is " + list.size());}

					} catch (HibernateException e) {

						e.printStackTrace();

						throw e;

					}

					//getTarget and add to child node

					if (logger.isTraceEnabled()){logger.trace("initialize bulk loaded " + node + " collections - DONE");}

					for (Object parentBean : list){

                        try {

						    Object propValue = PropertyUtils.getProperty(

						            parentBean,

						            mapFieldToPropertyName(param, parentBean.getClass().getSimpleName())

						          );

							if (propValue == null){

							    logger.trace("Collection is null");

							}else {

							    if(propValue instanceof PersistentMap) {

							        propValue = ((PersistentMap)propValue).values();

							    }

							    for(Object newBean : (Collection<Object>)propValue ) {

							        if(newBean instanceof HibernateProxy){

							            newBean = initializeInstance(newBean);

							        }

							        autoinitializeBean((CdmBase)newBean, autoInit);

							        node.addBean(newBean);

							    }

							}

                        } catch (Exception e) {

                            // TODO better throw an exception ?

                            logger.error("error while getting collection property", e);

                        }

					}

					if (logger.isTraceEnabled()){logger.trace("bulk load " + node + " collections - DONE");}

				}

			}

		}

		for (AbstractPersistentCollection collection : node.getUninitializedCollections()){

			if (! collection.wasInitialized()){  //should not happen anymore

				collection.forceInitialization();

				if (logger.isTraceEnabled()){logger.trace("forceInitialization of collection " + collection);}

			} else {

			    if (logger.isTraceEnabled()){logger.trace("collection " + collection + " is initialized - OK!");}

			}

		}

		node.resetLazyCollections();

		if (logger.isDebugEnabled()){logger.debug("bulk load " +  node + " - DONE ");}

	}

    private AutoInit addAutoinitFetchLoading(Class<?> clazz, String beanAlias) {

        AutoInit autoInit = new AutoInit();

        if(clazz != null) {

            Set<AutoPropertyInitializer<CdmBase>> inits = getAutoInitializers(clazz);

            for (AutoPropertyInitializer<CdmBase> init: inits){

                try {

                    autoInit.leftJoinFetch +=init.hibernateFetchJoin(clazz, beanAlias);

                } catch (Exception e) {

                    // the AutoPropertyInitializer is not supporting LEFT JOIN FETCH so it needs to be

                    // used explicitly

                    autoInit.initlializers.add(init);

                }

            }

        }

        return autoInit;

    }

    private Set<AutoPropertyInitializer<CdmBase>> getAutoInitializers(Class<?> clazz) {

        Set<AutoPropertyInitializer<CdmBase>> result = new HashSet<AutoPropertyInitializer<CdmBase>>();

        for(Class<? extends CdmBase> superClass : getBeanAutoInitializers().keySet()){

            if(superClass.isAssignableFrom(clazz)){

                result.add(getBeanAutoInitializers().get(superClass));

            }

        }

        return result;

    }

    /**

     * Rename hibernate (field) attribute to Bean property name, due to bean inconsistencies

     * #3841

     * @param param

     * @param ownerClass

     * @return

     */

    private String mapFieldToPropertyName(String param, String ownerClass) {

        if (ownerClass.contains("Description") && param.equals("descriptionElements")){

            return "elements";

        }

        if (ownerClass.startsWith("FeatureNode") && param.equals("children")) {

            return "childNodes";

        }

        if (ownerClass.startsWith("Media") && param.equals("description")) {

            return "allDescriptions";

        }

        else{

            return param;

        }

    }

    /**

     * @param node

     * @param property

     * @param index

     * @param bean

     * @param unwrappedPropertyBean

     */

    private void initializeNodeSinglePropertyOld(BeanInitNode node, String property,

            Integer index, Object bean, Object unwrappedPropertyBean) {

        Collection<?> collection = null;

        if(Map.class.isAssignableFrom(unwrappedPropertyBean.getClass())) {

            collection = ((Map<?,?>)unwrappedPropertyBean).values();

        }else if (Collection.class.isAssignableFrom(unwrappedPropertyBean.getClass())) {

            collection =  (Collection<?>) unwrappedPropertyBean;

        }

        if (collection != null){

            //collection or map

            if (logger.isTraceEnabled()){logger.trace(" initialize collection for " + node.toStringNoWildcard() + " ... ");}

            int i = 0;

            for (Object entrybean : collection) {

                if(index == null){

                    node.addBean(entrybean);

                } else if(index.equals(i)){

                    node.addBean(entrybean);

                    break;

                }

                i++;

            }

            if (logger.isTraceEnabled()){logger.trace(" initialize collection for " + node.toString() + " - DONE ");}

        }else {

            // nested bean

            node.addBean(unwrappedPropertyBean);

            setProperty(bean, property, unwrappedPropertyBean);

        }

    }

    private class AutoInit{

        String leftJoinFetch = "";

        Set<AutoPropertyInitializer<CdmBase>> initlializers = new HashSet<AutoPropertyInitializer<CdmBase>>();

        /**

         * @param leftJoinFetch

         * @param initlializers

         */

        public AutoInit() {

        }

    }

}