EDIT

/**

* Copyright (C) 2017 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.service;

import org.apache.log4j.Logger;

import org.hibernate.Session;

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

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

import org.springframework.transaction.TransactionStatus;

import com.vaadin.spring.annotation.SpringComponent;

import com.vaadin.spring.annotation.ViewScope;

import com.vaadin.ui.Notification;

import com.vaadin.ui.UI;

import eu.etaxonomy.cdm.api.application.CdmRepository;

import eu.etaxonomy.cdm.api.service.DeleteResult;

import eu.etaxonomy.cdm.api.service.IService;

import eu.etaxonomy.cdm.model.agent.AgentBase;

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

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

import eu.etaxonomy.cdm.model.name.NameTypeDesignation;

import eu.etaxonomy.cdm.model.name.Registration;

import eu.etaxonomy.cdm.model.name.TaxonName;

import eu.etaxonomy.cdm.model.occurrence.Collection;

import eu.etaxonomy.cdm.model.occurrence.SpecimenOrObservationBase;

import eu.etaxonomy.cdm.model.reference.Reference;

import eu.etaxonomy.cdm.vaadin.event.EntityChangeEvent;

import eu.etaxonomy.cdm.vaadin.event.EntityChangeEvent.Type;

import eu.etaxonomy.vaadin.mvp.AbstractView;

/**

 * @author a.kohlbecker

 * @since Jun 26, 2017

 *

 * TODO better naming of this class, ServiceWrapper, ServiceOperator, ...?

 *

 */

@SpringComponent

@ViewScope

public class CdmStore {

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

    @Autowired

    @Qualifier("cdmRepository")

    private CdmRepository repo;

    /**

     * If the bean is contained in the session it is being updated by doing an

     * evict and merge. The fieldGroup is updated with the merged bean.

     *

     *

     * @param bean

     * @return The bean merged to the session or original bean in case a merge

     *         was not necessary.

     */

    public <T extends CdmBase> T mergedBean(T bean) throws IllegalStateException {

        TransactionStatus txStatus = repo.startTransaction();

        Session session = repo.getSession();

        if (session.contains(bean)) {

            // evict bean before merge to avoid duplicate beans in same session

            logger.trace(this._toString() + ".mergedBean() - evict " + bean.toString());

            session.evict(bean);

        }

        logger.trace(this._toString() + ".mergedBean() - doing merge of" + bean.toString());

        @SuppressWarnings("unchecked")

        T mergedBean = (T) session.merge(bean);

        session.flush();

        repo.commitTransaction(txStatus);

        logger.trace(this._toString() + ".mergedBean() - bean after merge " + bean.toString());

        return mergedBean;

    }

    protected String _toString() {

        return this.getClass().getSimpleName() + "@" + this.hashCode();

    }

    /**

     *

     * @param bean

     *

     * @return the merged bean, this bean is <b>not reloaded</b> from the

     *         persistent storage.

     */

    public <T extends CdmBase> EntityChangeEvent saveBean(T bean, AbstractView view) {

        Type changeEventType;

        if(bean.isPersited()){

            changeEventType = Type.MODIFIED;

        } else {

            changeEventType = Type.CREATED;

        }

        TransactionStatus txStatus = repo.startTransaction();

        Session session = repo.getSession();

        logger.trace(this._toString() + ".onEditorSaveEvent - merging bean into session");

        // merge the changes into the session, ...

        T mergedBean = mergedBean(bean);

        session.flush();

        repo.commitTransaction(txStatus);

        return new EntityChangeEvent(mergedBean, changeEventType, view);

                repo.getTransactionManager().rollback(txStatus);

                throw e;

            }

    }

    /**

     *

     * @param bean

     * @return a EntityChangeEvent in case the deletion was successful otherwise <code>null</code>.

     */

    public final <T extends CdmBase> EntityChangeEvent deleteBean(T bean, AbstractView view) {

        IService<T> typeSpecificService = serviceFor(bean);

        logger.trace(this._toString() + ".onEditorPreSaveEvent - starting transaction");

        TransactionStatus txStatus = repo.startTransaction();

        Session session = repo.getSession();

        logger.trace(this._toString() + ".deleteBean - deleting" + bean.toString());

        DeleteResult result = typeSpecificService.delete(bean);

        if (result.isOk()) {

            session.flush();

            repo.commitTransaction(txStatus);

            logger.trace(this._toString() + ".deleteBean - transaction comitted");

            return new EntityChangeEvent(bean, Type.REMOVED, view);

        } else {

            handleDeleteresultInError(result);

        }

        return null;

    }

    /**

     * @param result

     */

    public static void handleDeleteresultInError(DeleteResult result) {

        String notificationTitle;

        StringBuffer messageBody = new StringBuffer();

        if (result.isAbort()) {

            notificationTitle = "The delete operation as abborded by the system.";

        } else {

            notificationTitle = "An error occured during the delete operation.";

        }

        if (!result.getExceptions().isEmpty()) {

            messageBody.append("<h3>").append("Exceptions:").append("</h3>").append("<ul>");

            result.getExceptions().forEach(e -> messageBody.append("<li>").append(e.getMessage()).append("</li>"));

            messageBody.append("</ul>");

        }

        if (!result.getRelatedObjects().isEmpty()) {

            messageBody.append("<h3>").append("Related objects exist:").append("</h3>").append("<ul>");

            result.getRelatedObjects().forEach(e -> {

                messageBody.append("<li>");

                if (IdentifiableEntity.class.isAssignableFrom(e.getClass())) {

                    messageBody.append(((IdentifiableEntity) e).getTitleCache());

                } else {

                    messageBody.append(e.toString());

                }

                messageBody.append("</li>");

            });

            messageBody.append("</ul>");

        }

        Notification notification = new Notification(notificationTitle, messageBody.toString(),

                com.vaadin.ui.Notification.Type.ERROR_MESSAGE, true);

        notification.show(UI.getCurrent().getPage());

    }

    @SuppressWarnings("unchecked")

    protected <T extends CdmBase> IService<T> serviceFor(T bean){

         Class<? extends CdmBase> cdmType = bean.getClass();

         if(Registration.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getRegistrationService();

         } else if(TaxonName.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getNameService();

         } else if(Reference.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getReferenceService();

         } else if (NameTypeDesignation.class.isAssignableFrom(cdmType)){

             throw new RuntimeException("no generic sercvice for NameTypeDesignation, use dedicated methods of NameService");

         } else if (SpecimenOrObservationBase.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getOccurrenceService();

         } else if (AgentBase.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getAgentService();

         } else if (Collection.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getCollectionService();

         } else if (Collection.class.isAssignableFrom(cdmType)){

             return (IService<T>) repo.getCollectionService();

         } else {

             throw new RuntimeException("Implementation to find service for " + cdmType + " still missing.");

         }

    }

}