/**
    * 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.drop;
  
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.ui.contentapp.browser.drop.DropConstraint;
  
  import javax.jcr.Item;
  import javax.jcr.Node;
  import javax.jcr.Property;
  import javax.jcr.RepositoryException;
  
  import com.vaadin.shared.ui.grid.DropLocation;
  
  import lombok.Setter;
  import lombok.SneakyThrows;
  
  /**
   * Default drop constraint for JCR content apps.
   *
   * Compares node types of source and target nodes.
   */
  public class JcrDropConstraint implements DropConstraint<Item> {
  
      @Setter
      private String primaryNodeType;
  
      @SneakyThrows(RepositoryException.class)
      @Override
      public boolean isAllowedAt(Item source, Item targetItem, DropLocation location) {
          switch (location) {
          case ON_TOP:
              return allowedAsChild(source, targetItem);
          case BELOW:
          case ABOVE:
              return allowedAsSibling(source, targetItem);
          }
          return false;
      }
  
      private boolean allowedAsChild(Item source, Item target) throws RepositoryException {
          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, return false
              if (source.isNode()
                      && NodeUtil.isNodeType((Node) source, NodeTypes.Folder.NAME)
                      && !NodeUtil.isNodeType((Node) target, NodeTypes.Folder.NAME)) {
                  return false;
              }
              Node targetNode = (Node) target;
  
              if (source.isNode()) {
                  Node sourceNode = (Node) source;
                  // If both nodes are of specific primaryNodeType, return false.
                  if (primaryNodeType != null && NodeUtil.isNodeType(sourceNode, primaryNodeType) && NodeUtil.isNodeType(targetNode, primaryNodeType)) {
                      return false;
                  }
                  return targetNode.getPrimaryNodeType().canAddChildNode(sourceNode.getName(), sourceNode.getPrimaryNodeType().getName());
              } else {
                  Property sourceProperty = (Property) source;
                 if (sourceProperty.isMultiple()) {
                     return targetNode.getPrimaryNodeType().canSetProperty(sourceProperty.getName(), sourceProperty.getValues());
                 } else {
                     return targetNode.getPrimaryNodeType().canSetProperty(sourceProperty.getName(), sourceProperty.getValue());
                 }
             }
         }
         return false;
     }
 
     private boolean basicCheck(Item source, Item target) throws RepositoryException {
         // Cannot move anythings to property
         if (!target.isNode()) {
             return false;
         }
         // Destination is not itself nor a descendant of source
         return !isAncestorOf(source, target);
     }
 
     private boolean isAncestorOf(Item ancestor, Item node) throws RepositoryException {
         return node.getPath().startsWith(ancestor.getPath() + "/");
     }
 
     private boolean allowedAsSibling(Item source, Item target) throws RepositoryException {
         // Property is not movable
         if (!source.isNode()) {
             return false;
         }
         boolean movable = basicCheck(source, target);
         // Cannot move after/before node which has sibling with same name and different parent
         return (!movable ||
                 // Cannot move after/before node which has sibling with same name and different parent
                 !target.getParent().hasNode(source.getName()) || target.getParent().isSame(source.getParent())) && movable;
     }
 }