EDIT

// $Id$

/**

 * Copyright (C) 2009 EDIT

 * European Distributed Institute of Taxonomy

 * http://www.e-taxonomy.eu

 *

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

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

import java.beans.PropertyDescriptor;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.lang.reflect.ParameterizedType;

import java.lang.reflect.Type;

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 javax.persistence.Transient;

import org.apache.commons.beanutils.PropertyUtils;

import org.apache.commons.lang.StringUtils;

import org.apache.log4j.Logger;

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

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

import eu.etaxonomy.cdm.persistence.dao.IMethodCache;

/**

 * @author a.kohlbecker

 * @date 26.03.2009

 *

 */

public abstract class AbstractBeanInitializer implements IBeanInitializer{

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

    @Autowired

    private IMethodCache methodCache;

    private Map<Class<? extends CdmBase>, AutoPropertyInitializer<CdmBase>> beanAutoInitializers = null;

    /**

     * @param beanAutoInitializers the beanAutoInitializers to set

     */

    public void setBeanAutoInitializers(Map<Class<? extends CdmBase>, AutoPropertyInitializer<CdmBase>> beanAutoInitializers) {

        this.beanAutoInitializers = beanAutoInitializers;

    }

    /**

     * @return the beanAutoInitializers

     */

    public Map<Class<? extends CdmBase>, AutoPropertyInitializer<CdmBase>> getBeanAutoInitializers() {

        return beanAutoInitializers;

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.cdm.persistence.dao.BeanInitializer#initializeInstance(java.lang.Object)

     */

    @Override

    public abstract Object initializeInstance(Object proxy);

    /* (non-Javadoc)

     * @see eu.etaxonomy.cdm.persistence.dao.BeanInitializer#load(eu.etaxonomy.cdm.model.common.CdmBase)

     */

    @Override

    public void load(Object bean) {

        initializeBean(bean, true, false);

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.cdm.persistence.dao.BeanInitializer#loadFully(eu.etaxonomy.cdm.model.common.CdmBase)

     */

    @Override

    public void loadFully(Object bean) {

        initializeBean(bean, true, true);

    }

    /**

     * Initializes all *toOne relations of the given bean and all *toMany

     * relations, depending on the state of the boolean parameters

     * <code>cdmEntities</code> and <code>collections</code>

     *

     * @param bean

     *            the bean to initialize

     * @param cdmEntities

     *            initialize all *toOne relations to cdm entities

     * @param collections

     *            initialize all *toMany relations

     */

    public void initializeBean(Object bean, boolean cdmEntities, boolean collections){

        if(logger.isDebugEnabled()){logger.debug(">> starting wildcard initializeBean() of " + bean + " ;class:" + bean.getClass().getSimpleName()); }

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

        if(cdmEntities){

            restrictions.add(CdmBase.class);

        }

        if(collections){

            restrictions.add(Collection.class);

        }

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

        for(PropertyDescriptor propertyDescriptor : props){

            try {

                invokeInitialization(bean, propertyDescriptor);

            } 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.isDebugEnabled()){

            logger.debug("  completed initializeBean() of " + bean);

        }

    }

    /* (non-Javadoc)

     * @see eu.etaxonomy.cdm.persistence.dao.BeanInitializer#initializeProperties(java.lang.Object, java.util.List)

     */

    //TODO optimize algorithm ..

    @Override

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

        invokePropertyAutoInitializers(bean);

        if(propertyPaths == null){

            return;

        }

        Collections.sort(propertyPaths);

        //long startTime1 = System.nanoTime();

        if(logger.isDebugEnabled()){

            logger.debug(">> starting to initialize " + bean + " ;class:" + bean.getClass().getSimpleName());

        }

        for(String propPath : propertyPaths){

            initializePropertyPath(bean, propPath);

        }

        //long estimatedTime1 = System.nanoTime() - startTime1;

        //System.err.println(".");

        //long startTime2 = System.nanoTime();

        //for(String propPath : propertyPaths){

        //	initializePropertyPath(bean, propPath);

        //}

        //long estimatedTime2 = System.nanoTime() - startTime2;

        //System.err.println("first pas: "+estimatedTime1+" ns; second pas: "+estimatedTime2+ " ns");

        if(logger.isDebugEnabled()){

            logger.debug("   Completed initialization of " + bean);

        }

    }

    @Override

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

        if(propertyPaths != null){

            for(Object bean : beanList){

                initialize(bean, propertyPaths);

            }

        }

        return beanList;

    }

    /**

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

     *

     * @param bean

     * @param propPath

     */

    //changed form private to protected  (AM)

    protected void initializePropertyPath(Object bean, String propPath) {

        if(logger.isDebugEnabled()){

            logger.debug("processing " + propPath);

        }

        // [1]

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

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

        if(propPath.equals(LOAD_2ONE_WILDCARD)){

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

                initializeAllEntries((Collection)bean, true, false);

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

                initializeAllEntries(((Map)bean).values(), true, false);

            } else{

                initializeBean(bean, true, false);

            }

        } else if(propPath.equals(LOAD_2ONE_2MANY_WILDCARD)){

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

                initializeAllEntries((Collection)bean, true, true);

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

                initializeAllEntries(((Map)bean).values(), true, true);

            } else {

                initializeBean(bean, true, true);

            }

        } else {

            // [2]

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

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

            String property;

            String nestedPath = null;

            int pos;

            if((pos = propPath.indexOf('.')) > 0){

                nestedPath = propPath.substring(pos + 1);

                property = propPath.substring(0, pos);

            } else {

                property = propPath;

            }

            // 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);

            }

            try {

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

                // [2.a] initialize the bean named by property

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

                Object unwrappedPropertyBean = invokeInitialization(bean, propertyDescriptor);

                // [2.b]

                // recurse into nested properties

                if(unwrappedPropertyBean != null && nestedPath != null){

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

                        // nested collection

                        int i = 0;

                        for (Object entrybean : (Collection<?>) unwrappedPropertyBean) {

                            if(index == null){

                                initializePropertyPath(entrybean, nestedPath);

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

                                initializePropertyPath(entrybean, nestedPath);

                                break;

                            }

                            i++;

                        }

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

                        // nested map

                        int i = 0;

                        for (Object entrybean : ((Map) unwrappedPropertyBean).values()) {

                            if(index == null){

                                initializePropertyPath(entrybean, nestedPath);

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

                                initializePropertyPath(entrybean, nestedPath);

                                break;

                            }

                            i++;

                        }

                    }else {

                        // nested bean

                        initializePropertyPath(unwrappedPropertyBean, nestedPath);

                        setProperty(bean, property, unwrappedPropertyBean);

                    }

                }

            } catch (IllegalAccessException e) {

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

            } catch (InvocationTargetException e) {

                logger.error("Cannot invoke property " + property + " not found");

            } catch (NoSuchMethodException e) {

                logger.info("Property " + property + " not found");

            }

        }

    }

    /**

     * Initializes the property of the given bean and returns the bean which is returned be that property.

     *

     * @param bean

     * @param propertyDescriptor

     * @return

     * @throws IllegalAccessException

     * @throws InvocationTargetException

     * @throws NoSuchMethodException

     */

    protected Object invokeInitialization(Object bean, PropertyDescriptor propertyDescriptor) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {

        if(propertyDescriptor == null || bean == null){

            return null;

        }

        // (1)

        // initialialization of the bean

        //

        Object propertyProxy = PropertyUtils.getProperty( bean, propertyDescriptor.getName());

        Object propertyBean = initializeInstance(propertyProxy);

        if(propertyBean != null){

            // (2)

            // auto initialialization of sub properties

            //

            if(CdmBase.class.isAssignableFrom(propertyBean.getClass())){

                // initialization of a single bean

                CdmBase cdmBaseBean = (CdmBase)propertyBean;

                invokePropertyAutoInitializers(cdmBaseBean);

            } else if(Collection.class.isAssignableFrom(propertyBean.getClass()) ||

                    Map.class.isAssignableFrom(propertyBean.getClass()) ) {

                // it is a collection or map

                Method readMethod = propertyDescriptor.getReadMethod();

                Type genericReturnType = readMethod.getGenericReturnType();

                if(genericReturnType instanceof ParameterizedType){

                    ParameterizedType type = (ParameterizedType) genericReturnType;

                    Type[] typeArguments = type.getActualTypeArguments();

                    if(typeArguments.length > 0

                            && typeArguments[0] instanceof Class<?>

                            && CdmBase.class.isAssignableFrom((Class<?>) typeArguments[0])){

                        if(Collection.class.isAssignableFrom((Class<?>) type.getRawType())){

                            for(CdmBase entry : ((Collection<CdmBase>)propertyBean)){

                                invokePropertyAutoInitializers(entry);

                            }

                        }

                    }

                }

            }

        }

        return propertyBean;

    }

    /**

     * @param beanClass

     * @param bean

     * @return

     */

    protected final void invokePropertyAutoInitializers(Object bean) {

        if(beanAutoInitializers == null || bean == null){

            return;

        }

        if(!CdmBase.class.isAssignableFrom(bean.getClass())){

            return;

        }

        CdmBase cdmBaseBean = (CdmBase)bean;

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

            if(superClass.isAssignableFrom(bean.getClass())){

                beanAutoInitializers.get(superClass).initialize(cdmBaseBean);

            }

        }

    }

    protected void setProperty(Object object, String property, Object value){

        Method method = methodCache.getMethod(object.getClass(), "set" + StringUtils.capitalize(property), value.getClass());

        if(method != null){

            try {

                method.invoke(object, value);

            } catch (IllegalArgumentException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (IllegalAccessException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (InvocationTargetException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

    /**

     * @param collection of which all entities are to be initialized

     * @param cdmEntities initialize all *toOne relations to cdm entities

     * @param collections initialize all *toMany relations

     */

    protected void initializeAllEntries(Collection collection, boolean cdmEntities, boolean collections) {

        for(Object bean : collection){

            initializeBean(bean, cdmEntities, collections);

        }

    }

    /**

     * Return all public bean properties exclusive those whose return type

     * match any class defined in the parameter <code>typeRestrictions</code>

     * or which are transient properties.

     *

     *

     * @param bean

     * @param typeRestrictions

     * @return

     */

    public static Set<PropertyDescriptor> getProperties(Object bean, Set<Class<?>> typeRestrictions) {

        Set<PropertyDescriptor> properties = new HashSet<PropertyDescriptor>();

        PropertyDescriptor[] props = PropertyUtils.getPropertyDescriptors(bean);

        for (PropertyDescriptor prop : props) {

            //String propName = prop[i].getName();

            // only read methods & skip transient getters

            if( prop.getReadMethod() != null ){

                  try{

                     Class<Transient> transientClass = (Class<Transient>)Class.forName( "javax.persistence.Transient" );

                     if( prop.getReadMethod().getAnnotation( transientClass ) != null ){

                        continue;

                     }

                  }catch( ClassNotFoundException cnfe ){

                     // ignore

                  }

                  if(typeRestrictions != null){

                      for(Class<?> restrictedType : typeRestrictions){

                          if(restrictedType.isAssignableFrom(prop.getPropertyType())){

                              properties.add(prop);

                          }

                      }

                  } else {

                      properties.add(prop);

                  }

            }

        }

        return properties;

    }

}