/**
    * This file Copyright (c) 2011-2014 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.jcr.util;
  
  import info.magnolia.cms.core.MgnlNodeType;
  import info.magnolia.cms.core.Path;
  import info.magnolia.cms.security.AccessDeniedException;
  import info.magnolia.cms.security.PermissionUtil;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.jcr.RuntimeRepositoryException;
  import info.magnolia.jcr.iterator.NodeIterableAdapter;
  import info.magnolia.jcr.predicate.AbstractPredicate;
  import info.magnolia.jcr.wrapper.DelegateNodeWrapper;
  import info.magnolia.jcr.wrapper.JCRPropertiesFilteringNodeWrapper;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.LinkedHashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Queue;
  import java.util.Set;
  
  import javax.jcr.ImportUUIDBehavior;
  import javax.jcr.Node;
  import javax.jcr.NodeIterator;
  import javax.jcr.PathNotFoundException;
  import javax.jcr.Property;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  import javax.jcr.nodetype.NodeType;
  import javax.jcr.nodetype.NodeTypeManager;
  import javax.jcr.query.Row;
  import javax.jcr.query.RowIterator;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang.RandomStringUtils;
  import org.apache.commons.lang.StringUtils;
  import org.apache.jackrabbit.JcrConstants;
  import org.apache.jackrabbit.commons.iterator.FilteringNodeIterator;
  import org.apache.jackrabbit.commons.iterator.NodeIteratorAdapter;
  import org.apache.jackrabbit.commons.predicate.NodeTypePredicate;
  import org.apache.jackrabbit.commons.predicate.Predicate;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Various utility methods to collect data from JCR repository.
   *
   * @version $Id$
   */
  public class NodeUtil {
  
      private static final Logger log = LoggerFactory.getLogger(NodeUtil.class);
  
      /**
       * Node filter accepting everything except nodes with namespace jcr (version and system store).
       */
      public static Predicate ALL_NODES_EXCEPT_JCR_FILTER = new AbstractPredicate<Node>() {
          @Override
          public boolean evaluateTyped(Node node) {
             try {
                 return !node.getName().startsWith(MgnlNodeType.JCR_PREFIX);
             } catch (RepositoryException e) {
                 return false;
             }
         }
     };
 
     /**
      * Node filter accepting everything except meta data and jcr types.
      */
     public static AbstractPredicate<Node> EXCLUDE_META_DATA_FILTER = new AbstractPredicate<Node>() {
 
         @Override
         public boolean evaluateTyped(Node node) {
             try {
                 return !node.getName().startsWith(MgnlNodeType.JCR_PREFIX)
                 && !NodeUtil.isNodeType(node, MgnlNodeType.NT_METADATA);
             } catch (RepositoryException e) {
                 return false;
             }
         }
     };
 
     /**
      * Node filter accepting all nodes of a type with namespace mgnl.
      */
     public static AbstractPredicate<Node> MAGNOLIA_FILTER = new AbstractPredicate<Node>() {
 
         @Override
         public boolean evaluateTyped(Node node) {
 
             try {
                 String nodeTypeName = node.getPrimaryNodeType().getName();
                 // accept only "magnolia" nodes
                 return nodeTypeName.startsWith(MgnlNodeType.MGNL_PREFIX);
             } catch (RepositoryException e) {
                 // TODO should we really mask this error? shouldn't it be thrown instead?
                 log.error("Unable to read nodetype for node {}", getNodePathIfPossible(node));
             }
             return false;
         }
     };
 
     /**
      * Get a Node by identifier.
      */
     public static Node getNodeByIdentifier(String workspace, String identifier) throws RepositoryException {
         Node target = null;
         Session jcrSession;
         if (workspace == null || identifier == null) {
             return target;
         }
 
         jcrSession = MgnlContext.getJCRSession(workspace);
         if (jcrSession != null) {
             target = jcrSession.getNodeByIdentifier(identifier);
         }
         return target;
     }
 
     /**
      * from default content.
      */
     public static boolean hasMixin(Node node, String mixinName) throws RepositoryException {
         if (StringUtils.isBlank(mixinName)) {
             throw new IllegalArgumentException("Mixin name can't be empty.");
         }
         for (NodeType type : node.getMixinNodeTypes()) {
             if (mixinName.equals(type.getName())) {
                 return true;
             }
         }
         return false;
     }
 
     /**
      * TODO dlipp: better name? Clear javadoc! Move to MetaDataUtil, do not assign method-param! TODO cringele :
      * shouldn't @param nodeType be aligned to JCR API? There it is nodeTypeName, nodeType is used for NodeType object
      */
     public static boolean isNodeType(Node node, String type) throws RepositoryException {
         node = NodeUtil.deepUnwrap(node, JCRPropertiesFilteringNodeWrapper.class);
         final String actualType = node.getProperty(MgnlNodeType.JCR_PRIMARY_TYPE).getString();
         // if the node is frozen, and we're not looking specifically for frozen nodes, then we compare with the original
         // node type
         if (MgnlNodeType.NT_FROZENNODE.equals(actualType) && !(MgnlNodeType.NT_FROZENNODE.equals(type))) {
             final Property p = node.getProperty(MgnlNodeType.JCR_FROZEN_PRIMARY_TYPE);
             final String s = p.getString();
             NodeTypeManager ntManager = node.getSession().getWorkspace().getNodeTypeManager();
             NodeType primaryNodeType = ntManager.getNodeType(s);
             return primaryNodeType.isNodeType(type);
         }
         return node.isNodeType(type);
     }
 
     public static Node unwrap(Node node) throws RepositoryException {
         Node unwrappedNode = node;
         while (unwrappedNode instanceof DelegateNodeWrapper) {
             unwrappedNode = ((DelegateNodeWrapper) unwrappedNode).getWrappedNode();
         }
         return unwrappedNode;
     }
 
     /**
      * Removes a wrapper by type. The wrapper can be deep in a chain of wrappers in which case wrappers before it will
      * be cloned creating a new chain that leads to the same real node.
      */
     public static Node deepUnwrap(Node node, Class<? extends DelegateNodeWrapper> wrapper) {
         if (node instanceof DelegateNodeWrapper) {
             return ((DelegateNodeWrapper) node).deepUnwrap(wrapper);
         }
         return node;
     }
 
     /**
      * Removes all wrappers of a given type. Other wrappers are cloned creating a new chain that leads to the same real
      * node.
      */
     public static Node deepUnwrapAll(Node node, Class<? extends DelegateNodeWrapper> wrapperClass) {
         while (node instanceof DelegateNodeWrapper) {
             Node unwrapped = ((DelegateNodeWrapper) node).deepUnwrap(wrapperClass);
             // If the unwrapping had no effect we're done
             if (unwrapped == node) {
                 break;
             }
             node = unwrapped;
         }
         return node;
     }
 
     public static boolean isWrappedWith(Node node, Class<? extends DelegateNodeWrapper> wrapper) {
         if (wrapper.isInstance(node)){
             return true;
         }
 
         if (node instanceof DelegateNodeWrapper) {
             return isWrappedWith(((DelegateNodeWrapper)node).getWrappedNode(), wrapper);
         }
         return false;
     }
 
 
     /**
      * Convenience - delegate to {@link Node#orderBefore(String, String)}.
      */
     public static void orderBefore(Node node, String siblingName) throws RepositoryException {
         node.getParent().orderBefore(node.getName(), siblingName);
     }
 
     /**
      * Orders the node directly after a given sibling. If no sibling is specified the node is placed first.
      */
     public static void orderAfter(Node node, String siblingName) throws RepositoryException {
 
         if (siblingName == null) {
             orderFirst(node);
             return;
         }
 
         Node parent = node.getParent();
         Node sibling = parent.getNode(siblingName);
         Node siblingAfter = getSiblingAfter(sibling);
 
         if (siblingAfter == null) {
             orderLast(node);
             return;
         }
 
         // Move the node before the sibling directly after the target sibling
         parent.orderBefore(node.getName(), siblingAfter.getName());
     }
 
     /**
      * Orders the node first among its siblings.
      */
     public static void orderFirst(Node node) throws RepositoryException {
         Node parent = node.getParent();
         NodeIterator siblings = parent.getNodes();
         Node firstSibling = siblings.nextNode();
         if (!firstSibling.isSame(node)) {
             parent.orderBefore(node.getName(), firstSibling.getName());
         }
     }
 
     /**
      * Orders the node last among its siblings.
      */
     public static void orderLast(Node node) throws RepositoryException {
         node.getParent().orderBefore(node.getName(), null);
     }
 
     /**
      * Orders the node up one step among its siblings. If the node is the only sibling or the first sibling this method
      * has no effect.
      */
     public static void orderNodeUp(Node node) throws RepositoryException {
         Node siblingBefore = getSiblingBefore(node);
         if (siblingBefore != null) {
             node.getParent().orderBefore(node.getName(), siblingBefore.getName());
         }
     }
 
     /**
      * Orders the node down one step among its siblings. If the node is the only sibling or the last sibling this method
      * has no effect.
      */
     public static void orderNodeDown(Node node) throws RepositoryException {
         Node siblingAfter = getSiblingAfter(node);
         if (siblingAfter != null) {
             node.getParent().orderBefore(siblingAfter.getName(), node.getName());
         }
     }
 
     public static Node getSiblingBefore(Node node) throws RepositoryException {
         Node parent = node.getParent();
         NodeIterator siblings = parent.getNodes();
         Node previousSibling = null;
         while (siblings.hasNext()) {
             Node sibling = siblings.nextNode();
             if (isSame(node, sibling)) {
                 return previousSibling;
             }
             previousSibling = sibling;
         }
         return null;
     }
 
     public static Node getSiblingAfter(Node node) throws RepositoryException {
         Node parent = node.getParent();
         NodeIterator siblings = parent.getNodes();
         while (siblings.hasNext()) {
             Node sibling = siblings.nextNode();
             if (isSame(node, sibling)) {
                 break;
             }
         }
         return siblings.hasNext() ? siblings.nextNode() : null;
     }
 
     /**
      * Gets the siblings of this node.
      * @param node node from which will be siblings retrieved
      * @param nodeTypeName requested type of siblings nodes
      * @return list of siblings of the given Node (only the given node is excluded)
      */
     public static Iterable<Node> getSiblings(Node node) throws RepositoryException {
         Node parent = node.getParent();
         Iterable<Node> allSiblings = NodeUtil.getNodes(parent);
         List<Node> siblings = new ArrayList<Node>();
 
         for(Node sibling: allSiblings) {
             if (!NodeUtil.isSame(node, sibling)) {
                 siblings.add(sibling);
             }
         }
         return siblings;
     }
 
     /**
      * Gets the siblings of this node with certain type.
      * @param node node from which will be siblings retrieved
      * @param nodeTypeName requested type of siblings nodes
      * @return list of siblings of the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblings(Node node, String nodeTypeName) throws RepositoryException {
         Node parent = node.getParent();
         Iterable<Node> allSiblings = NodeUtil.getNodes(parent, nodeTypeName);
         List<Node> sameTypeSiblings = new ArrayList<Node>();
 
         for(Node sibling: allSiblings) {
             if (!NodeUtil.isSame(node, sibling)) {
                 sameTypeSiblings.add(sibling);
             }
         }
         return sameTypeSiblings;
     }
 
     /**
      * Gets the siblings of this node according to predicate.
      * @param node node from which will be siblings retrieved
      * @param predicate predicate
      * @return list of siblings of the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblings(Node node, Predicate predicate) throws RepositoryException {
         Node parent = node.getParent();
         Iterable<Node> allSiblings = NodeUtil.getNodes(parent, predicate);
         List<Node> sameTypeSiblings = new ArrayList<Node>();
 
         for(Node sibling: allSiblings) {
             if (!NodeUtil.isSame(node, sibling)) {
                 sameTypeSiblings.add(sibling);
             }
         }
         return sameTypeSiblings;
     }
 
     /**
      * Gets the siblings before this node.
      * @param node node from which will be siblings retrieved
      * @return list of siblings before the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblingsBefore(Node node) throws RepositoryException {
         int toIndex = 0;
         Node parent = node.getParent();
         List<Node> allSiblings = NodeUtil.asList(NodeUtil.getNodes(parent));
 
         for(Node sibling: allSiblings) {
             if (NodeUtil.isSame(node, sibling)) {
                 break;
             }
             toIndex++;
         }
         return allSiblings.subList(0, toIndex);
     }
 
     /**
      * Gets the siblings after this node.
      * @param node node from which will be siblings retrieved
      * @return list of siblings after the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblingsAfter(Node node) throws RepositoryException {
         int fromIndex = 0;
         Node parent = node.getParent();
         List<Node> allSiblings = NodeUtil.asList(NodeUtil.getNodes(parent));
 
         for(Node sibling: allSiblings) {
             if (NodeUtil.isSame(node, sibling)) {
                 fromIndex++;
                 break;
             }
             fromIndex++;
         }
         return allSiblings.subList(fromIndex, allSiblings.size());
     }
 
     /**
      * Gets the siblings before this node with certain type.
      * @param node node from which will be siblings retrieved
      * @param nodeTypeName requested type of siblings nodes
      * @return list of siblings before the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblingsBefore(Node node, String nodeTypeName) throws RepositoryException {
         Node parent = node.getParent();
         Iterable<Node> allSiblings = NodeUtil.getNodes(parent);
         List<Node> sameTypeSiblings = new ArrayList<Node>();
 
         for(Node sibling: allSiblings) {
             if (NodeUtil.isSame(node, sibling)) {
                 break;
             }
             if (isNodeType(sibling, nodeTypeName)) {
                 sameTypeSiblings.add(sibling);
             }
         }
         return sameTypeSiblings;
     }
 
     /**
      * Gets the siblings after this node with certain type.
      * @param node node from which will be siblings retrieved
      * @param nodeTypeName requested type of siblings nodes
      * @return list of siblings after the given Node (the given node is excluded)
      */
     public static Iterable<Node> getSiblingsAfter(Node node, String nodeTypeName) throws RepositoryException {
         Node parent = node.getParent();
         List<Node> allSiblings = NodeUtil.asList(NodeUtil.getNodes(parent));
         int fromIndex = 0;
 
         for(Node sibling: allSiblings) {
             fromIndex++;
             if (NodeUtil.isSame(node, sibling)) {
                 break;
             }
         }
 
         List<Node> sameTypeSiblings = new ArrayList<Node>();
         for(Node sibling: allSiblings.subList(fromIndex, allSiblings.size())) {
             if (isNodeType(sibling, nodeTypeName)) {
                 sameTypeSiblings.add(sibling);
             }
         }
         return sameTypeSiblings;
     }
 
     public static void moveNode(Node nodeToMove, Node newParent) throws RepositoryException {
         if (!isSame(newParent, nodeToMove.getParent())) {
             String newPath = combinePathAndName(newParent.getPath(), nodeToMove.getName());
             nodeToMove.getSession().move(nodeToMove.getPath(), newPath);
         }
     }
 
     public static void moveNodeBefore(Node nodeToMove, Node target) throws RepositoryException {
         Node targetParent = target.getParent();
         moveNode(nodeToMove, targetParent);
         targetParent.orderBefore(nodeToMove.getName(), target.getName());
     }
 
     public static void moveNodeAfter(Node nodeToMove, Node target) throws RepositoryException {
         Node targetParent = target.getParent();
         moveNode(nodeToMove, targetParent);
         orderAfter(nodeToMove, target.getName());
     }
 
     public static boolean isFirstSibling(Node node) throws RepositoryException {
         Node parent = node.getParent();
         NodeIterator nodes = parent.getNodes();
         return isSame(nodes.nextNode(), node);
     }
 
     /**
      * Check if node1 and node2 are siblings.
      */
     public static boolean isSameNameSiblings(Node node1, Node node2) throws RepositoryException {
         Node parent1 = node1.getParent();
         Node parent2 = node2.getParent();
         return isSame(parent1, parent2) && node1.getName().equals(node2.getName());
     }
 
     public static boolean isLastSibling(Node node) throws RepositoryException {
         Node parent = node.getParent();
         NodeIterator nodes = parent.getNodes();
         Node last = null;
         while (nodes.hasNext()) {
             last = nodes.nextNode();
         }
         return isSame(last, node);
     }
 
     public static void renameNode(Node node, String newName) throws RepositoryException {
         if (node.getName().equals(newName)) {
             return;
         }
         final Node parent = node.getParent();
         final String newPath = combinePathAndName(parent.getPath(), newName);
         final Node siblingAfter = NodeUtil.getSiblingAfter(node);
 
         node.getSession().move(node.getPath(), newPath);
 
         if (siblingAfter != null) {
             parent.orderBefore(newName, siblingAfter.getName());
         }
     }
 
 
     /**
      * @return Whether the provided node as the provided permission or not.
      * @throws RuntimeException
      *             in case of RepositoryException.
      */
     public static boolean isGranted(Node node, long permissions) {
         try {
             return PermissionUtil.isGranted(node, permissions);
         } catch (RepositoryException e) {
             // TODO dlipp - apply consistent ExceptionHandling
             throw new RuntimeException(e);
         }
     }
 
     /**
      * Returns true if both arguments represents the same node. In case the nodes are wrapped the comparison is done one
      * the actual nodes behind the wrappers.
      */
     public static boolean isSame(Node lhs, Node rhs) throws RepositoryException {
         return unwrap(lhs).isSame(unwrap(rhs));
     }
 
     public static String combinePathAndName(String path, String name) {
         if ("/".equals(path)) {
             return "/" + name;
         }
         return path + "/" + name;
     }
 
     /**
      * Creates a node under the specified parent and relative path, then returns it. Should the node already exist, the
      * method will simply return it.
      */
     public static Node createPath(Node parent, String relPath, String primaryNodeTypeName) throws RepositoryException, PathNotFoundException, AccessDeniedException {
         return createPath(parent, relPath, primaryNodeTypeName, false);
     }
 
     /**
      * Creates a node under the specified parent and relative path, then returns it. Should the node already exist, the
      * method will simply return it.
      */
     public static Node createPath(Node parent, String relPath, String primaryNodeTypeName, boolean save) throws RepositoryException, PathNotFoundException, AccessDeniedException {
         // remove leading /
         String currentPath = StringUtils.removeStart(relPath, "/");
 
         if (StringUtils.isEmpty(currentPath)) {
             return parent;
         }
 
         Node root = parent;
         String[] names = currentPath.split("/");
 
         for (int i = 0; i < names.length; i++) {
             String name = names[i];
             if (root.hasNode(name)) {
                 root = root.getNode(name);
             } else {
                 final Node newNode = root.addNode(name, primaryNodeTypeName);
                 if (newNode.canAddMixin(JcrConstants.MIX_LOCKABLE)) {
                     newNode.addMixin(JcrConstants.MIX_LOCKABLE);
                 }
                 if (save) {
                     root.getSession().save();
                 }
                 root = newNode;
             }
         }
         return root;
     }
 
     /**
      * Visits the given node and then all of nodes beneath it except for metadata nodes and nodes of jcr type.
      */
     public static void visit(Node node, NodeVisitor visitor) throws RepositoryException {
         visit(node, visitor, EXCLUDE_META_DATA_FILTER);
     }
 
     public static void visit(Node node, NodeVisitor visitor, Predicate predicate) throws RepositoryException {
         // TODO should it really visit the start node even if it doesn't match the filter?
         visitor.visit(node);
         for (Node child : getNodes(node, predicate)) {
             visit(child, visitor, predicate);
         }
         if (visitor instanceof PostNodeVisitor) {
             ((PostNodeVisitor) visitor).postVisit(node);
         }
     }
 
     public static Iterable<Node> getNodes(Node parent, Predicate predicate) throws RepositoryException {
         return asIterable(new FilteringNodeIterator(parent.getNodes(), predicate));
     }
 
     public static Iterable<Node> getNodes(Node parent) throws RepositoryException {
         return getNodes(parent, EXCLUDE_META_DATA_FILTER);
     }
 
     public static Iterable<Node> getNodes(Node parent, String nodeTypeName) throws RepositoryException {
         return getNodes(parent, new NodeTypePredicate(nodeTypeName, false));
     }
 
     public static Iterable<Node> asIterable(NodeIterator iterator) {
         return new NodeIterableAdapter(iterator);
     }
 
     public static List<Node> asList(Iterable<Node> nodes) {
         List<Node> nodesList = new ArrayList<Node>();
         for (Node node : nodes) {
             nodesList.add(node);
         }
         return nodesList;
     }
 
     /**
      * This method return the node's name on success, otherwise it handles the {@link RepositoryException} by throwing a
      * {@link RuntimeRepositoryException}.
      */
     public static String getName(Node content) {
         try {
             return content.getName();
         } catch (RepositoryException e) {
             throw new RuntimeRepositoryException(e);
         }
     }
 
     /**
      * Get all children (by recursion) using MAGNOLIA_FILTER (filter accepting all nodes of a type with namespace mgnl).
      */
     public static Iterable<Node> collectAllChildren(Node node) throws RepositoryException {
         List<Node> nodes = new ArrayList<Node>();
         return collectAllChildren(nodes, node, MAGNOLIA_FILTER);
     }
 
     /**
      * Get all children (by recursion) using a Predicate.
      */
     public static Iterable<Node> collectAllChildren(Node node, Predicate predicate) throws RepositoryException {
         List<Node> nodes = new ArrayList<Node>();
         return collectAllChildren(nodes, node, predicate);
     }
 
     /**
      * Get all children (by recursion) using a Predicate.
      * // TODO this method should really be private or renamed
      */
     public static Iterable<Node> collectAllChildren(List<Node> nodes, Node parent, Predicate predicate) throws RepositoryException {
         // get filtered sub nodes first
         nodes.addAll(asList(getNodes(parent, predicate)));
 
         // get all children to find recursively
         Iterator<Node> allChildren = getNodes(parent, EXCLUDE_META_DATA_FILTER).iterator();
 
         // recursion
         while (allChildren.hasNext()) {
             collectAllChildren(nodes, allChildren.next(), predicate);
         }
 
         return nodes;
     }
 
     /**
      * Get all Ancestors until level 1.
      */
     public static Collection<Node> getAncestors(Node node) throws RepositoryException {
         List<Node> allAncestors = new ArrayList<Node>();
         int level = node.getDepth();
         while (level != 0) {
             try {
                 allAncestors.add((Node) node.getAncestor(--level));
             } catch (AccessDeniedException e) {
                 log.debug("Node " + node.getIdentifier() + " didn't allow access to Ancestor's ");
             }
         }
         return allAncestors;
     }
 
     /**
      * Used for building exception messages where we want to avoid handling another exception inside a throws clause.
      */
     public static String getNodeIdentifierIfPossible(Node content) {
         try {
             return content.getIdentifier();
         } catch (RepositoryException e) {
             return "<not available>";
         }
     }
 
     public static String getNodePathIfPossible(Node node) {
         try {
             return node.getPath();
         } catch (RepositoryException e) {
             return "<not available>";
         }
     }
 
     /**
      * Return the Path of the node.
      *
      * @return the path for the node or an empty String in case of exception
      */
     public static String getPathIfPossible(Node node) {
         try {
             return node.getPath();
         } catch (RepositoryException e) {
             log.error("Failed to get handle: " + e.getMessage(), e);
             return StringUtils.EMPTY;
         }
     }
 
     public static NodeIterator filterNodeType(NodeIterator iterator, String nodeType){
         return new FilteringNodeIterator(iterator, new info.magnolia.jcr.predicate.NodeTypePredicate(nodeType));
     }
 
     public static NodeIterator filterDuplicates(NodeIterator iterator){
         return new FilteringNodeIterator(iterator, new info.magnolia.jcr.predicate.DuplicateNodePredicate());
     }
 
     public static NodeIterator filterParentNodeType(NodeIterator iterator, final String nodeType) throws RepositoryException{
         return new FilteringNodeIterator(iterator, new info.magnolia.jcr.predicate.NodeTypeParentPredicate(nodeType)) {
             @Override
             public Node nextNode(){
                 Node node = super.nextNode();
                 try {
                     while(node.getDepth() != 0 && !node.isNodeType(nodeType)){
                         if(node.getDepth() != 0){
                             node = node.getParent();
                         }
                     }
                 } catch (RepositoryException e) {
                     throw new RuntimeException(e.getMessage(), e);
                 }
                 return node;
             }
         };
     }
 
     /**
      * Filters rows of result set from query by provided selector and returns such nodes in the NodeIterator. Example of such query would be
      * <i>SELECT page.* FROM [mgnl:page] AS page WHERE page.title like 'something%'</i>. Selector in this query is <i>page</i>
      *
      * @param iterator RowIterator from the result set of executed query
      * @param selector Selector used in the query to identify nodes
      * @return NodeIterator containing only nodes identified by the selector
      */
     public static NodeIterator filterParentNodeType(RowIterator iterator, final String selector) throws RepositoryException {
         return new NodeIteratorAdapter(iterator) {
             @Override
             public Node nextNode() throws NoSuchElementException {
                 Row row = (Row) next();
                 try {
                     return row.getNode(selector);
                 } catch (RepositoryException e) {
                     // no way to pass a root cause to NSEE
                     log.debug(e.getMessage(), e);
                     throw new NoSuchElementException(e.getMessage());
                 }
             }
         };
     }
 
     public static Collection<Node> getCollectionFromNodeIterator(NodeIterator iterator){
         Collection<Node> nodeCollection = new LinkedHashSet<Node>(150);
         while(iterator.hasNext()){
             nodeCollection.add(iterator.nextNode());
         }
         return nodeCollection;
     }
 
     public static Node getSameNameSiblingNode(Node siblingNode) throws RepositoryException {
         Node parentNode = siblingNode.getParent();
         long sameNameSiblingNumber = parentNode.getNodes(siblingNode.getName()).getSize();
         if (sameNameSiblingNumber > 1) {
             return siblingNode;
         }
         return findSameNameSiblingNode(siblingNode);
     }
 
     private static Node findSameNameSiblingNode(Node rootNode) throws RepositoryException {
         Set<String> names = new HashSet<String>();
         Queue<NodeIterator> queue = new LinkedList<NodeIterator>();
         queue.add(rootNode.getNodes());
         while (!queue.isEmpty()) {
             NodeIterator children = queue.poll();
             while (children.hasNext()) {
                 Node child = children.nextNode();
                 if (names.contains(child.getName())) {
                     return child;
                 }
                 names.add(child.getName());
                 queue.add(child.getNodes());
             }
             names.clear();
         }
 
         return null;
     }
 
     /**
      * Session based copy operation. <br>
      * As JCR only supports workspace based copies this operation is performed by using export import operations.<br>
      * <br>
      * If no node exists one level above destAbsPath (in other words, there is no node that will serve as the parent of the moved item) then a PathNotFoundException is thrown either immediately, on dispatch or on persist. <br>
      * Note that if a node already exists at destAbsPath, the operation succeeds, <b>but the original properties and children values are kept</b>. No merge or override are performed.
      * Also be aware that the source Node is copied recursively (i.e. with all its subnodes) to the destination path.
      */
     public static void copyInSession(Node src, String destAbsPath) throws RepositoryException {
         final Session session = src.getSession();
         final String destTmpNodeName = Path.getUniqueLabel(session, src.getParent().getPath(), "tmp_" + RandomStringUtils.randomAlphabetic(12));
         final String destTmpParentPath = combinePathAndName(src.getParent().getPath(), destTmpNodeName);
         final Node destTmpNode = createPath(src.getParent(), destTmpNodeName, src.getPrimaryNodeType().getName());
         FileInputStream inStream = null;
         FileOutputStream outStream = null;
         File file = null;
         try {
             file = File.createTempFile("mgnl", null, Path.getTempDirectory());
             outStream = new FileOutputStream(file);
             session.exportSystemView(src.getPath(), outStream, false, false);
             outStream.flush();
             IOUtils.closeQuietly(outStream);
             inStream = new FileInputStream(file);
             session.importXML(
                     destTmpParentPath,
                     inStream,
                     ImportUUIDBehavior.IMPORT_UUID_CREATE_NEW);
 
             String currentPath = destTmpParentPath + "/" + src.getName();
             session.move(currentPath, destAbsPath);
 
         } catch (IOException e) {
             throw new RepositoryException("Can't copy node " + src + " to " + destAbsPath, e);
         } finally {
             IOUtils.closeQuietly(inStream);
             IOUtils.closeQuietly(outStream);
             if (file != null) {
                 file.delete();
             }
             destTmpNode.remove();
         }
     }
 }