/**
    * This file Copyright (c) 2018 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.ui.databinding.converter;
  
  import info.magnolia.cms.util.PathUtil;
  import info.magnolia.ui.datasource.jcr.JcrDatasourceDefinition;
  import info.magnolia.ui.datasource.jcr.JcrSessionManager;
  
  import java.util.Optional;
  
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import com.vaadin.data.Converter;
  import com.vaadin.data.Result;
  import com.vaadin.data.ValueContext;
  
  import lombok.SneakyThrows;
  
  /**
   * JCR-specific implementation of {@link Converter}. Turns a Node (presentation type) into its identifier (model type or a String) and vice versa.
   * Converting to presentation will attempt to resolve a node either from its identifier or its path.
   */
  public class JcrItemToLinkConverter implements Converter<Node, String> {
  
      private final JcrDatasourceDefinition definition;
      private final JcrSessionManager contentDecorator;
  
      public JcrItemToLinkConverter(JcrDatasourceDefinition definition, JcrSessionManager contentDecorator) {
          this.definition = definition;
          this.contentDecorator = contentDecorator;
      }
  
      @SneakyThrows(RepositoryException.class)
      @Override
      public Result<String> convertToModel(Node value, ValueContext context) {
          if (value == null) {
              return Result.ok(null);
          }
          return Result.ok(value.getIdentifier());
      }
  
      @Override
      public Node convertToPresentation(String value, ValueContext context) {
          if (value == null) {
              return null;
          }
          return resolveNodeByIdOrPath(value);
      }
  
      private Node resolveNodeByIdOrPath(String value) {
              // if value isn't an id, it may be a node name used for setting a default value
              return Optional.ofNullable(getNodeByIdSafely(value))
                      .orElseGet(() -> getNodeByPath(value));
      }
      
      private Session getSession() throws RepositoryException {
          return contentDecorator.getJCRSession();
      }
  
      private Node getNodeByIdSafely(String value) {
          try {
              return getSession().getNodeByIdentifier(value);
          } catch (RepositoryException e) {
              // here we ignore the exception as value may be a path
              return null;
          }
     }
 
     @SneakyThrows(RepositoryException.class)
     private Node getNodeByPath(String value) {
         return getSession().getNode(PathUtil.createPath(definition.getRootPath(), value));
     }
 }