/**
    * 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.contentapp;
  
  import static java.util.Spliterators.spliterator;
  
  import info.magnolia.context.Context;
  import info.magnolia.jcr.RuntimeRepositoryException;
  import info.magnolia.ui.datasource.jcr.JcrDatasourceDefinition;
  import info.magnolia.ui.framework.datasource.components.HierarchySupport;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Optional;
  import java.util.Spliterator;
  import java.util.stream.Stream;
  import java.util.stream.StreamSupport;
  
  import javax.inject.Inject;
  import javax.inject.Provider;
  import javax.jcr.Item;
  import javax.jcr.Node;
  import javax.jcr.NodeIterator;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import lombok.SneakyThrows;
  
  /**
   * {@link HierarchySupport} implementation for the JCR nodes.
   */
  public class JcrWorkspaceHierarchySupport implements HierarchySupport<Item> {
  
      private static final Logger log = LoggerFactory.getLogger(JcrWorkspaceHierarchySupport.class);
  
      private final JcrDatasourceDefinition jcrDatasourceDefinition;
      private final Provider<Context> contextProvider;
  
      @Inject
      public JcrWorkspaceHierarchySupport(JcrDatasourceDefinition jcrDatasourceDefinition, Provider<Context> contextProvider) {
          this.jcrDatasourceDefinition = jcrDatasourceDefinition;
          this.contextProvider = contextProvider;
      }
  
      @Override
      @SneakyThrows
      public Stream<Item> getRootItems() {
          return nodeIteratorToStream(getSession().getRootNode().getNodes());
      }
  
      @Override
      @SneakyThrows
      public Stream<Item> getChildren(Item parent) {
          if (!parent.isNode()) {
              return Stream.empty();
          }
          return nodeIteratorToStream(((Node) parent).getNodes());
      }
  
      @Override
      public Stream<Item> getParents(Item item) {
          try {
              if (!item.isNode()) {
                  return Stream.of(item.getParent());
              }
             final List<Item> parents = new ArrayList<>();
             Optional<Item> parent = getDirectParent(item);
             while (parent.isPresent()) {
                 parents.add(parent.get());
                 parent = getDirectParent(parent.get());
             }
             return parents.stream();
         } catch (RepositoryException e) {
             log.debug("Failed to resolve Node parent");
             return Stream.empty();
         }
     }
 
     @Override
     @SneakyThrows
     public Optional<Item> getDirectParent(Item item) {
         if (item.getDepth() == 0) {
             return Optional.empty();
         }
 
         return Optional.of(item.getParent());
     }
 
     @SuppressWarnings("unchecked")
     private Stream<Item> nodeIteratorToStream(NodeIterator nodeIterator) {
         return StreamSupport.stream(
                 spliterator(
                         nodeIterator,
                         nodeIterator.getSize(),
                         Spliterator.DISTINCT | Spliterator.NONNULL),
                 false);
     }
 
     private Session getSession() {
         try {
             return this.contextProvider.get().getJCRSession(this.jcrDatasourceDefinition.getWorkspace());
         } catch (RepositoryException e) {
             throw new RuntimeRepositoryException(e);
         }
     }
 }