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.remote.json.processor.bean;

import java.beans.PropertyDescriptor;

import java.lang.reflect.InvocationTargetException;

import java.util.Collection;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import net.sf.json.JSONException;

import net.sf.json.JSONObject;

import net.sf.json.JsonConfig;

import net.sf.json.processors.JsonBeanProcessor;

import net.sf.json.processors.JsonValueProcessor;

import net.sf.json.processors.JsonVerifier;

import net.sf.json.util.PropertyFilter;

import org.apache.commons.beanutils.PropertyUtils;

import org.apache.log4j.Logger;

import org.hibernate.Hibernate;

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

import eu.etaxonomy.cdm.persistence.dao.initializer.AbstractBeanInitializer;

/**

 * @author a.kohlbecker

 * @date 30.03.2009

 *

 */

public abstract class AbstractBeanProcessor<T extends Object> implements JsonBeanProcessor{

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

    private Set<String> excludes = new HashSet<String>();

    private Set<String> mergedExcludes = null;

    public Set<String> getExcludes() {

        return excludes;

    }

    /**

     * This method allows supplying a List of property names to be ignored

     * during the serialization to JSON. The <code>excludes</code> will be

     * merged with the property names configured by subclasses which override

     * {@link {@link #getIgnorePropNames()}.

     *

     * @param excludes

     */

    public void setExcludes(Set<String> excludes) {

        this.excludes = excludes;

    }

    /**

     * Implementations of this abstract class may override this method in order

     * to supply a List of property names to be ignored in

     * {@link #processBean(Object, JsonConfig)}. This feature generally is used

     * when {@link #processBeanSecondStep(CdmBase, JSONObject, JsonConfig)} is

     * implemented. such that this method is responsible of serializing this

     * property.

     *

     * @return a List of property names.

     */

    public abstract List<String> getIgnorePropNames();

    /**

     * merges and returns {@link {@link #getIgnorePropNames()} with

     * {@link #excludes}

     *

     * @return

     */

    protected Set<String> getMergedExcludes(){

        if(mergedExcludes  == null) {

            mergedExcludes = new HashSet<String>(excludes);

            if(getIgnorePropNames() != null){

                mergedExcludes.addAll(getIgnorePropNames());

            }

        }

        return mergedExcludes;

    }

    /**

     *

     * @param json

     * @param jsonConfig

     * @param fieldName

     * @param fieldObject

     */

    protected void addJsonElement(JSONObject json, JsonConfig jsonConfig, String fieldName,	Object fieldObject) {

        if(Hibernate.isInitialized(fieldObject)){

            json.element(fieldName, fieldObject, jsonConfig);

        }

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public final JSONObject processBean(Object bean, JsonConfig jsonConfig) {

        if(logger.isDebugEnabled()){

            logger.debug("processing " + bean.getClass());

        }

        JSONObject json =  new JSONObject();

        Collection<?> exclusions = jsonConfig.getMergedExcludes( bean.getClass() );

        Set<PropertyDescriptor> props = AbstractBeanInitializer.getProperties(bean, null);

        PropertyFilter jsonPropertyFilter = jsonConfig.getJsonPropertyFilter();

        for(PropertyDescriptor prop: props){

            String key = prop.getName();

            if(getMergedExcludes().contains(key) || exclusions.contains(key)){

                if(logger.isDebugEnabled()){

                    logger.debug("skipping excluded property " + key);

                }

                continue;

            }

            try {

                // ------ reusing snippet from JSONOnbject._fromBean()

                Class<?> type = prop.getPropertyType();

                Object value = PropertyUtils.getProperty( bean, key );

                if( jsonPropertyFilter != null && jsonPropertyFilter.apply( bean, key, value ) ){

                   continue;

                }

                JsonValueProcessor jsonValueProcessor = jsonConfig.findJsonValueProcessor(bean.getClass(), type, key );

                if( jsonValueProcessor != null ){

                   value = jsonValueProcessor.processObjectValue( key, value, jsonConfig );

                   if( !JsonVerifier.isValidJsonValue( value ) ){

                      throw new JSONException( "Value is not a valid JSON value. " + value );

                   }

                }

                // ----- END of snipped

                if(logger.isDebugEnabled()){

                    logger.debug("processing " + key + " of " + bean.getClass());

                }

                if(CdmBase.class.isAssignableFrom(type)){

                    json.element(key, value, jsonConfig);

                } else if(Collection.class.isAssignableFrom(type) || Map.class.isAssignableFrom(type)){

                    json.element(key, value, jsonConfig);

                }  else if(Object.class.isAssignableFrom(type)){

                    json.element(key, value, jsonConfig);

                } else {

                    json.element(key, value);

                }

            } catch (IllegalAccessException e) {

                logger.error(e.getMessage(), e);

            } catch (InvocationTargetException e) {

                logger.error(e.getMessage(), e);

            } catch (NoSuchMethodException e) {

                logger.error(e.getMessage(), e);

            }

        }

        json = processBeanSecondStep((T) bean, json, jsonConfig);

        return json;

    }

    /**

     * This method is called ate the end of {@link #processBean(Object, JsonConfig)} just before the JSONObject is returned.

     * By overriding this method it is possible to to further processing.

     * <p>

     * <b>See also {@link #getIgnorePropNames()}!</b>

     *

     * @param bean

     * @param json

     * @param jsonConfig

     * @return

     */

    public abstract JSONObject processBeanSecondStep(T bean, JSONObject json, JsonConfig jsonConfig) ;

}