/**
    * This file Copyright (c) 2011 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.templating.editor.client.widget.dnd;
  
  import static info.magnolia.templating.editor.client.jsni.JavascriptUtils.moveComponent;
  import info.magnolia.templating.editor.client.PageEditor;
  import info.magnolia.templating.editor.client.dom.MgnlElement;
  import info.magnolia.templating.editor.client.widget.controlbar.ComponentBar;
  import info.magnolia.templating.editor.client.widget.placeholder.ComponentPlaceHolder;
  
  import com.google.gwt.dom.client.Element;
  import com.google.gwt.event.dom.client.DragEndEvent;
  import com.google.gwt.event.dom.client.DragEndHandler;
  import com.google.gwt.event.dom.client.DragLeaveEvent;
  import com.google.gwt.event.dom.client.DragLeaveHandler;
  import com.google.gwt.event.dom.client.DragOverEvent;
  import com.google.gwt.event.dom.client.DragOverHandler;
  import com.google.gwt.event.dom.client.DragStartEvent;
  import com.google.gwt.event.dom.client.DragStartHandler;
  import com.google.gwt.event.dom.client.DropEvent;
  import com.google.gwt.event.dom.client.DropHandler;
  
  /**
   * DragAndDropImpl.
   */
  public class DragAndDropImpl {
  
      public void dragAndDrop (final ComponentBar bar) {
          bar.addDomHandler(new DragStartHandler() {
              @Override
              public void onDragStart(DragStartEvent event) {
                  bar.toggleButtons(false);
  
                  bar.setStyleName("moveSource", true);
  
                  MgnlElement area = bar.getMgnlElement().getParentArea();
                  if (area != null) {
                      for (MgnlElement component : area.getComponents()) {
                          ComponentBar componentBar = (ComponentBar) PageEditor.model.getEditBar(component);
                          if (componentBar != null && componentBar != bar) {
                              componentBar.setStyleName("moveTarget", true);
                          }
                      }
                      ComponentPlaceHolder placeholder = (ComponentPlaceHolder) PageEditor.model.getComponentPlaceHolder(area);
                      if (placeholder != null) {
                          placeholder.setStyleName("moveOngoing", true);
                      }
                  }
  
                  int x = bar.getAbsoluteLeft();
                  int y = bar.getAbsoluteTop();
                  event.setData("text", bar.getNodeName() + "," + x +","+y);
                  event.getDataTransfer().setDragImage(bar.getElement(), 10, 10);
  
              }
          }, DragStartEvent.getType());
  
          bar.addDomHandler(new DragEndHandler() {
              @Override
              public void onDragEnd(DragEndEvent event) {
                  bar.toggleButtons(true);
  
                  bar.setStyleName("moveSource", false);
  
                  MgnlElement area = bar.getMgnlElement().getParentArea();
                  if (area != null) {
                      for (MgnlElement component : area.getComponents()) {
                          ComponentBar componentBar = (ComponentBar) PageEditor.model.getEditBar(component);
                         if (componentBar != null && componentBar != bar) {
                             componentBar.setStyleName("moveTarget", false);
                         }
                     }
                     ComponentPlaceHolder placeholder = (ComponentPlaceHolder) PageEditor.model.getComponentPlaceHolder(area);
                     if (placeholder != null) {
                         placeholder.setStyleName("moveOngoing", false);
                     }
                 }
             }
         }, DragEndEvent.getType());
 
         bar.addDomHandler(new DragOverHandler() {
             @Override
             public void onDragOver(DragOverEvent event) {
                 String data = event.getData("text");
                 String[] tokens = data.split(",");
                 String idSource = tokens[0];
 
                 if (!bar.getNodeName().equals(idSource)){
                     bar.setStyleName("moveOver", true);
                 }
                 event.stopPropagation();
             }
         }, DragOverEvent.getType());
 
         bar.addDomHandler(new DragLeaveHandler() {
 
             @Override
             public void onDragLeave(DragLeaveEvent event) {
                 bar.setStyleName("moveOver", false);
                 event.stopPropagation();
             }
         }, DragLeaveEvent.getType());
 
         bar.addDomHandler(new DropHandler() {
             @Override
             public void onDrop(DropEvent event) {
                 String data = event.getData("text");
                 String[] tokens = data.split(",");
                 String idSource = tokens[0];
 
                 if (!bar.getNodeName().equals(idSource)) {
                     int xTarget = bar.getAbsoluteLeft();
                     int yTarget = bar.getAbsoluteTop();
                     int xOrigin = Integer.valueOf(tokens[1]);
                     int yOrigin = Integer.valueOf(tokens[2]);
 
                     boolean isDragUp = yOrigin > yTarget;
                     boolean isDragDown = !isDragUp;
                     boolean isDragLeft = xOrigin > xTarget;
                     boolean isDragRight = !isDragLeft;
 
                     String order = null;
 
                     if(isDragUp || isDragLeft) {
                         order = "before";
                     } else if(isDragDown || isDragRight) {
                         order = "after";
                     }
                     String parentPath = bar.getPath().substring(0, bar.getPath().lastIndexOf("/"));
                     moveComponent(bar.getNodeName(), idSource, parentPath, order);
                 }
 
                 event.preventDefault();
             }
         }, DropEvent.getType());
 
         bar.getElement().setDraggable(Element.DRAGGABLE_TRUE);
     }
 }