/**
    * This file Copyright (c) 2009-2015 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.nodebuilder;
  
  import info.magnolia.jcr.iterator.FilteringNodeIterator;
  import info.magnolia.jcr.predicate.AbstractPredicate;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.jcr.util.PropertyUtil;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.jcr.ItemExistsException;
  import javax.jcr.ItemNotFoundException;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  import javax.jcr.Value;
  
  import org.apache.commons.collections.CollectionUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Factory methods for most common NodeOperation implementations.
   */
  public abstract class Ops {
      public static NodeOperation addNode(final String name) {
          return new AbstractNodeOperation() {
              @Override
              protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                  // TODO dlipp: Caution - addNode does not create/update Metadata (in contrast to Content#createContent! To be checked!
                  return context.addNode(name);
              }
          };
      }
  
      public static NodeOperation addNode(final String name, final String type) {
          return new AbstractNodeOperation() {
              @Override
              protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                  return context.addNode(name, type);
              }
          };
      }
  
      public static NodeOperation getNode(final String name) {
          return new AbstractNodeOperation() {
              @Override
              protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                  return context.getNode(name);
              }
          };
      }
  
      /**
       * Adds property. Throws an ItemExistsException if the property already exists.
       */
      public static NodeOperation addProperty(final String name, final String newValue) {
          return new AbstractNodeOperation() {
              @Override
              protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                  if (context.hasProperty(name)) {
                      throw new ItemExistsException("Property " + name + " already exists at " + context.getPath());
                  }
                  final Value value = PropertyUtil.createValue(newValue, context.getSession().getValueFactory());
                  context.setProperty(name, value);
                  return context;
              }
         };
     }
 
     /**
      * Sets the value of an existing property, ignoring its current value.
      * @throws ItemNotFoundException if the property does not exist.
      */
     public static NodeOperation setProperty(final String name, final Object newValue) {
         return new AbstractNodeOperation() {
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 if (!context.hasProperty(name)) {
                     throw new ItemNotFoundException(name);
                 }
                 final Value value = PropertyUtil.createValue(newValue, context.getSession().getValueFactory());
                 context.setProperty(name, value);
                 return context;
             }
         };
     }
 
     /**
      * Renames a node.
      */
     public static NodeOperation renameNode(final String currentName, final String newName) {
         return new AbstractNodeOperation() {
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 NodeUtil.renameNode(context.getNode(currentName), newName);
                 return context;
             }
         };
     }
 
     /**
      * Renames a property by creating a new one and copying the value.
      */
     public static NodeOperation renameProperty(final String name, final String newName) {
         return new AbstractNodeOperation() {
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 if (!context.hasProperty(name)) {
                     throw new ItemNotFoundException(name);
                 }
                 if (context.hasProperty(newName)) {
                     //throw new ItemExistsException("Property " + newName + " already exists at " + context.getHandle());
                     throw new ItemExistsException(newName);
                 }
                 final Value value = context.getProperty(name).getValue();
                 context.setProperty(newName, value);
                 context.getProperty(name).remove();
                 return context;
             }
         };
     }
 
     /**
      * Moves a node, using session-scoped operation.
      */
     public static NodeOperation moveNode(final String nodeName, final String dest) {
         return new AbstractNodeOperation() {
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 NodeUtil.moveNode(context.getNode(nodeName), context.getNode(dest));
                 return context;
             }
         };
     }
 
     /**
      * No operation; can be useful in ternary expression, for instance.
      */
     public static NodeOperation noop() {
         return new NodeOperation() {
             @Override
             public NodeOperation then(NodeOperation... childrenOps) {
                 return null;
             }
 
             @Override
             public void exec(Node context, ErrorHandler errorHandler) {
             }
         };
     }
 
     /**
      * Gets or adds node depending on whether it existed or not.
      */
     public static final NodeOperation getOrAddNode(final String name, final String nodeType) {
         return new AbstractNodeOperation() {
 
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 return (context.hasNode(name)) ? context.getNode(name) : context.addNode(name, nodeType);
             }
         };
     }
 
     /**
      * Executes then() ops on all child nodes. Use with care as it might result in modification of more nodes then intended.
      */
     public static final NodeOperation onChildNodes() {
         return onChildNodes(new AbstractPredicate<Node>() {
             @Override
             public boolean evaluateTyped(Node t) {
                 return true;
             }
         });
     }
 
     /**
      * Executes then() ops on all child nodes that are evaluated true by the predicate.
      */
     public static final NodeOperation onChildNodes(final AbstractPredicate<Node> predicate) {
         return new AbstractNodeOperation() {
             // yes we do want to log into ANO logger
             private final Logger log = LoggerFactory.getLogger(AbstractNodeOperation.class);
 
             private List<NodeOperation> childrenOps = new ArrayList<NodeOperation>();
 
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 return context;
             }
 
             @Override
             public void exec(Node context, ErrorHandler errorHandler) {
                 try {
                     FilteringNodeIterator iter = new FilteringNodeIterator(context.getNodes(), predicate);
                     while (iter.hasNext()) {
                         for (NodeOperation childrenOp : childrenOps) {
                             childrenOp.exec(iter.nextNode(), errorHandler);
                         }
                     }
                 } catch (RepositoryException e) {
                     try {
                         errorHandler.handle(e, context);
                     } catch (RepositoryException e1) {
                         log.warn("Could not handle original exception {} because of: ", e.getMessage(), e1);
                     }
                 }
 
             }
 
             @Override
             public NodeOperation then(NodeOperation... childrenOps) {
                 // add the operations to allow multiple calls on the method.
                 CollectionUtils.addAll(this.childrenOps, childrenOps);
                 return this;
             }
 
         };
     }
 
     /**
      * Executes all then() defined ops only when passed in flag is evaluated true, behaves as noop otherwise.
      * This is useful to switch off/on blocks of bigger operation chains without having to split them into too many small chunks.
      */
     public static final NodeOperation ifTrue(final boolean bool) {
         return new AbstractNodeOperation() {
 
             private List<NodeOperation> childrenOps = new ArrayList<NodeOperation>();
 
             @Override
             protected Node doExec(Node context, ErrorHandler errorHandler) throws RepositoryException {
                 return context;
             }
 
             @Override
             public void exec(Node context, ErrorHandler errorHandler) {
                 if (bool) {
                     for (NodeOperation childrenOp : childrenOps) {
                         childrenOp.exec(context, errorHandler);
                     }
                 }
             }
 
             @Override
             public NodeOperation then(NodeOperation... childrenOps) {
                 // add the operations to allow multiple calls on the method.
                 CollectionUtils.addAll(this.childrenOps, childrenOps);
                 return this;
             }
 
         };
     }
 }