/*
 * Copyright (c) 2009 Mysema Ltd.
 * All rights reserved.
 *
 */
package com.mysema.rdfbean.tapestry.services;

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.tapestry5.ioc.annotations.EagerLoad;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mysema.rdfbean.model.RDFBeanTransaction;
import com.mysema.rdfbean.object.Configuration;
import com.mysema.rdfbean.object.MappedClass;
import com.mysema.rdfbean.object.MappedPath;
import com.mysema.rdfbean.object.Session;
import com.mysema.rdfbean.object.SessionFactory;
import com.mysema.util.BeanMap;

@EagerLoad
public class SeedEntityImpl implements SeedEntity {

    private static final Logger logger = LoggerFactory.getLogger(SeedEntityImpl.class);

    private final Map<Object, Object> persisted;

    public SeedEntityImpl(
            Configuration configuration,
            SessionFactory sessionFactory,
            List<Object> entities) throws IOException {
        this.persisted = new HashMap<Object, Object>(entities.size());
        Session session = sessionFactory.openSession();
        RDFBeanTransaction tx = session.beginTransaction();
        try {
            for (Object entity : entities) {
                replaceReferences(configuration, entity);
                Object original = session.getByExample(entity);
                if (original == null) {
                    session.save(entity);
                } else {
                    persisted.put(entity, original);
                }
            }
            tx.commit();
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            tx.rollback();
        } finally {
            session.close();
        }

    }

    /**
     * Replace the references of the given entity with persisted ones
     * 
     * @param entity
     */
    private void replaceReferences(Configuration configuration, Object entity) {
        BeanMap beanMap = new BeanMap(entity);
        MappedClass mappedClass = configuration.getMappedClass(entity.getClass());
        for (MappedPath mappedPath : mappedClass.getProperties()) {
            if (mappedPath.isReference() && mappedPath.isSimpleProperty()) {
                Object value = mappedPath.getMappedProperty().getValue(beanMap);
                if (value != null && persisted.containsKey(value)) {
                    value = persisted.get(value);
                    mappedPath.getMappedProperty().setValue(beanMap, value);
                }
            }
        }
    }

}