/**
    * This file Copyright (c) 2017-2018 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.workbench.tree.drop;
  
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.ui.vaadin.integration.contentconnector.ContentConnector;
  import info.magnolia.ui.vaadin.integration.contentconnector.JcrContentConnector;
  import info.magnolia.ui.vaadin.integration.jcr.JcrItemAdapter;
  
  import javax.inject.Inject;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.vaadin.v7.data.Item;
  
  /**
   * Default drop constraint for content apps.
   *
   * Compares node types of source and target nodes.
   */
  public class JcrDropConstraint extends AlwaysTrueDropConstraint implements DropConstraint {
  
      private static final Logger log = LoggerFactory.getLogger(JcrDropConstraint.class);
  
      private final ContentConnector contentConnector;
  
      @Inject
      public JcrDropConstraint(ContentConnector contentConnector) {
          this.contentConnector = contentConnector;
      }
  
      /**
       * Backward compatibility constructor.
       *
       * @deprecated since 5.5.5, use {@link #JcrDropConstraint(ContentConnector)} instead.
       */
      @Deprecated
      public JcrDropConstraint() {
          this(null);
      }
  
      @Override
      public boolean allowedAsChild(Item sourceItem, Item targetItem) {
          if ((sourceItem instanceof JcrItemAdapter) && (targetItem instanceof JcrItemAdapter)) {
              JcrItemAdapter source = (JcrItemAdapter) sourceItem;
              JcrItemAdapter target = (JcrItemAdapter) targetItem;
  
              return allowedAsChild(source.getJcrItem(), target.getJcrItem());
          }
  
          return true;
      }
  
      protected boolean allowedAsChild(javax.jcr.Item source, javax.jcr.Item target) {
          try {
              boolean movable = basicCheck(source, target);
              if (movable) {
                  // Cannot move node/property to its parent
                  if (target.isSame(source.getParent())
                              // Forbid same-name siblings
                              || ((Node) target).hasNode(source.getName())
                              || ((Node) target).hasProperty(source.getName())) {
                      return false;
                 }
 
                 // If source is a folder and target is not a folder or root, return false
                 if (source.isNode()
                         && NodeUtil.isNodeType((Node) source, NodeTypes.Folder.NAME)
                         && !(isRoot(target) || NodeUtil.isNodeType((Node) target, NodeTypes.Folder.NAME))) {
                     log.debug("Could not move a Folder under a node", ((Node) source).getPrimaryNodeType().getName());
                     return false;
                 }
             }
 
             return movable;
         } catch (RepositoryException e) {
             log.warn("Cannot check allow as child due to exception: ", e);
         }
 
         return true;
     }
 
     protected boolean basicCheck(javax.jcr.Item source, javax.jcr.Item target) {
         // Cannot move anythings to property
         if (!target.isNode()) {
             log.debug("Could not move a node under a property");
             return false;
         }
 
         // Destination is not itself nor a descendant of source
         if (isAncestorOf(source, target)) {
             return false;
         }
 
         return true;
     }
 
     protected boolean isAncestorOf(javax.jcr.Item ancestor, javax.jcr.Item node) {
         try {
             for (javax.jcr.Item n = node; !isRoot(n); n = n.getParent()) {
                 if (ancestor.isSame(n)) {
                     return true;
                 }
             }
         } catch (RepositoryException e) {
             log.warn("Cannot get ancestor of item:", e);
         }
         return false;
     }
 
     protected boolean isRoot(javax.jcr.Item item) {
         try {
             // The check makes sure backward compatibility in injecting ContentConnector in {@link #JcrDropConstraint()}.
             String rootPath = contentConnector instanceof JcrContentConnector ? ((JcrContentConnector) contentConnector).getContentConnectorDefinition().getRootPath() : "/";
             if (item != null && item.isNode() && (item.getParent() == null || StringUtils.equals(item.getPath(), rootPath))) {
                 return true;
             }
         } catch (RepositoryException e) {
             return true;
         }
 
         return false;
     }
 
     @Override
     public boolean allowedBefore(Item sourceItem, Item targetItem) {
         if ((sourceItem instanceof JcrItemAdapter) && (targetItem instanceof JcrItemAdapter)) {
             JcrItemAdapter source = (JcrItemAdapter) sourceItem;
             JcrItemAdapter target = (JcrItemAdapter) targetItem;
 
             return allowedSibling(source.getJcrItem(), target.getJcrItem());
         }
         return true;
     }
 
     protected boolean allowedSibling(javax.jcr.Item source, javax.jcr.Item target) {
         try {
             // Property is not movable
             if (!source.isNode()) {
                 return false;
             }
 
             boolean movable = basicCheck(source, target);
             if (movable &&
                     // Cannot move before/after on root
                     (isRoot(target) ||
                     // Cannot move after/before node which has sibling with same name and different parent
                     target.getParent().hasNode(source.getName()) && !target.getParent().isSame(source.getParent()))) {
                 return false;
             }
 
             return movable;
         } catch (RepositoryException e) {
             log.warn("Cannot check allow before due to exception: ", e);
         }
 
         return true;
     }
 
     @Override
     public boolean allowedAfter(Item sourceItem, Item targetItem) {
         if ((sourceItem instanceof JcrItemAdapter) && (targetItem instanceof JcrItemAdapter)) {
             JcrItemAdapter source = (JcrItemAdapter) sourceItem;
             JcrItemAdapter target = (JcrItemAdapter) targetItem;
 
             return allowedSibling(source.getJcrItem(), target.getJcrItem());
         }
         return true;
     }
 
     @Override
     public boolean allowedToMove(Item sourceItem) {
         JcrItemAdapter jcrSourceItem = (JcrItemAdapter) sourceItem;
         return jcrSourceItem != null;
     }
 }