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.vaadin.mvp;

import java.util.Collection;

import java.util.EnumSet;

import java.util.HashSet;

import java.util.UUID;

import org.apache.log4j.Logger;

import org.hibernate.HibernateException;

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

import eu.etaxonomy.cdm.cache.CdmTransientEntityCacher;

import eu.etaxonomy.cdm.debug.PersistentContextAnalyzer;

import eu.etaxonomy.cdm.model.ICdmCacher;

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

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

import eu.etaxonomy.cdm.persistence.hibernate.permission.CRUD;

import eu.etaxonomy.cdm.persistence.hibernate.permission.CdmAuthority;

import eu.etaxonomy.cdm.service.CdmStore;

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

import eu.etaxonomy.cdm.vaadin.permission.UserHelper;

import eu.etaxonomy.cdm.vaadin.view.name.CachingPresenter;

import eu.etaxonomy.vaadin.mvp.event.EditorPreSaveEvent;

import eu.etaxonomy.vaadin.mvp.event.EditorSaveEvent;

/**

 * Provides generic save operations of modified cdm entities.

 *

 * @author a.kohlbecker

 * @since Apr 5, 2017

 *

 */

public abstract class CdmEditorPresenterBase<DTO, CDM extends CdmBase, V extends ApplicationView<?>> extends AbstractEditorPresenter<DTO, V>

    implements CachingPresenter {

    private static final long serialVersionUID = 2218185546277084261L;

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

    /**

     * if not null, this CRUD set is to be used to create a CdmAuthoritiy for the base entity which will be

     * granted to the current use as long this grant is not assigned yet.

     */

    protected EnumSet<CRUD> crud = null;

    private ICdmCacher cache;

    private java.util.Collection<CdmBase> rootEntities = new HashSet<>();

    public CdmEditorPresenterBase() {

        super();

        logger.trace(this._toString() + " constructor");

    }

    CdmStore<CDM, IService<CDM>> store ;

    protected CdmAuthority newAuthorityCreated;

    protected CdmStore<CDM, IService<CDM>> getStore() {

        if(store == null){

            store = new CdmStore<>(getRepo(), getService());

        }

        return store;

    }

    @Override

    protected DTO loadBeanById(Object identifier) {

        CDM cdmEntitiy;

        if(identifier != null) {

            UUID uuidIdentifier = (UUID)identifier;

            // CdmAuthority is needed before the bean is loaded into the session.

            // otherwise adding the authority to the user would cause a flush

            cdmEntitiy = loadCdmEntity(uuidIdentifier);

            guaranteePerEntityCRUDPermissions(cdmEntitiy);

        } else {

            cdmEntitiy = loadCdmEntity(null);

            if(cdmEntitiy != null){

                guaranteePerEntityCRUDPermissions(cdmEntitiy);

            }

        }

        cache = new CdmTransientEntityCacher(this);

        // need to use load but put see #7214

        cdmEntitiy = cache.load(cdmEntitiy);

        addRootEntity(cdmEntitiy);

        DTO dto = createDTODecorator(cdmEntitiy);

        return dto;

    }

    /**

     * @param cdmEntitiy

     * @return

     */

    protected abstract DTO createDTODecorator(CDM cdmEntitiy);

    /**

     * @param cdmEntitiy

     */

    @Override

    protected void adaptToUserPermission(DTO dto) {

        CDM cdmEntitiy = cdmEntity(dto);

        UserHelper userHelper = UserHelper.fromSession();

        boolean canDelte = userHelper.userHasPermission(cdmEntitiy, CRUD.DELETE);

        boolean canEdit = userHelper.userHasPermission(cdmEntitiy, CRUD.UPDATE);

        User user = userHelper.user();

        if(AbstractCdmPopupEditor.class.isAssignableFrom(getView().getClass())){

            AbstractCdmPopupEditor popupView = ((AbstractCdmPopupEditor)getView());

            if(!canEdit){

                popupView.setReadOnly(true); // never reset true to false here!

                logger.debug("setting editor to readonly");

            }

            if(!canDelte){

                popupView.withDeleteButton(false);

                logger.debug("removing delete button");

            }

        }

    }

    /**

     * @param dto

     * @return

     */

    protected abstract CDM cdmEntity(DTO dto);

    /**

     * @param identifier

     * @return

     */

    protected abstract CDM loadCdmEntity(UUID uuid);

    /**

     * Grant per entity CdmAuthority to the current user <b>for the bean which is not yet loaded</b>

     * into the editor. The <code>CRUD</code> to be granted are stored in the <code>crud</code> field.

     */

    protected abstract void guaranteePerEntityCRUDPermissions(UUID identifier);

    /**

     * Grant per entity CdmAuthority to the current user for the bean which is loaded

     * into the editor. The <code>CRUD</code> to be granted are stored in the <code>crud</code> field.

     */

     protected abstract void guaranteePerEntityCRUDPermissions(CDM bean);

    /**

     * @return

     */

    protected abstract IService<CDM> getService();

    @SuppressWarnings("unchecked")

    @Override

    // @EventBusListenerMethod // already annotated at super class

    public void onEditorPreSaveEvent(EditorPreSaveEvent preSaveEvent){

        if(!isFromOwnView(preSaveEvent)){

            return;

        }

        super.onEditorPreSaveEvent(preSaveEvent);

    }

    @Override

    // @EventBusListenerMethod // already annotated at super class

    public void onEditorSaveEvent(EditorSaveEvent<DTO> saveEvent){

        if(!isFromOwnView(saveEvent)){

            return;

        }

        // the bean is now updated with the changes made by the user

        DTO dto = saveEvent.getBean();

        CDM cdmEntity = cdmEntity(dto);

        if(logger.isTraceEnabled()){

            PersistentContextAnalyzer pca = new PersistentContextAnalyzer(cdmEntity);

            pca.printEntityGraph(System.err);

            pca.printCopyEntities(System.err);

        }

        if(logger.isTraceEnabled()){

            PersistentContextAnalyzer pca = new PersistentContextAnalyzer(cdmEntity);

            pca.printEntityGraph(System.err);

            pca.printCopyEntities(System.err);

        }

        EntityChangeEvent<?> changeEvent = null;

        try {

            dto = preSaveBean(dto);

            changeEvent = getStore().saveBean(cdmEntity, (AbstractView<?>) getView());

            if(changeEvent != null){

                viewEventBus.publish(this, changeEvent);

            }

        } catch (HibernateException e){

            if(newAuthorityCreated != null){

                UserHelper.fromSession().removeAuthorityForCurrentUser(newAuthorityCreated);

            }

            throw e;

        } finally {

            postSaveBean(changeEvent);

        }

    }

    /**

     * This method is intended to be used for the following purposes:

     * <ol>

     *   <li>

     *   EditorPresenters for beans with transient properties can overwrite this method to

     *   update the beanItem with the changes made to the transient properties.

     *   This can be necessary because Vaadin MethodProperties are readonly when no setter is

     *   available. This can be the case with transient properties. Automatic updating

     *   of the property during the fieldGroup commit does not work in this case.

     *   Presenters, however, should <b>operate on DTOs instead, which can implement the missing setter</b>.</li>

     *

     *   <li>When modifying a bi-directional relation between two instances the user would

     *   need to have GrantedAuthorities for both sides of the relationship. This, however is not

     *   always possible. As a temporary solution the user can be granted the missing authority just

     *   for the time of saving the new relationship. You may also want to implement

     *   {@link #postSaveBean(EntityChangeEvent)} in this case.

     *   See {@link https://dev.e-taxonomy.eu/redmine/issues/7390 #7390}

     *   </li>

     * </ol>

     *

     */

    protected DTO preSaveBean(DTO bean) {

        // blank implementation, to be implemented by sub classes if needed

        return bean;

    }

    @Override

    protected

    final void saveBean(DTO bean){

        // blank implementation, since this is not needed in this or any sub class

        // see onEditorSaveEvent() instead

    }

    /**

     * Called after saving the DTO to the persistent storage.

     * This method is called in any case even if the save operation failed.

     * See {@link  #postSaveBean(EntityChangeEvent)}.

     *

     * @param changeEvent may be null in case of errors during the save operation

     */

    protected void postSaveBean(EntityChangeEvent changeEvent) {

        // blank implementation, to be implemented by sub classes if needed

    }

    @Override

    protected void deleteBean(DTO bean){

        CDM cdmEntity = cdmEntity(bean);

        EntityChangeEvent changeEvent = getStore().deleteBean(cdmEntity, (AbstractView) getView());

        if(changeEvent != null){

            viewEventBus.publish(this, changeEvent);

        }

    }

    /**

     * @param crud

     */

    public void setGrantsForCurrentUser(EnumSet<CRUD> crud) {

        this.crud = crud;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public ICdmCacher getCache() {

        return cache;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public void addRootEntity(CdmBase entity) {

        rootEntities.add(entity);

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public Collection<CdmBase> getRootEntities() {

        return rootEntities;

    }

}