/**
    * This file Copyright (c) 2013-2014 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.ui.vaadin.gwt.client.editor.dom;
  
  import info.magnolia.cms.security.operations.OperationPermissionDefinition;
  import info.magnolia.ui.vaadin.gwt.client.editor.event.ComponentStartMoveEvent;
  import info.magnolia.ui.vaadin.gwt.client.editor.event.ComponentStopMoveEvent;
  import info.magnolia.ui.vaadin.gwt.client.editor.event.EditComponentEvent;
  import info.magnolia.ui.vaadin.gwt.client.editor.event.SortComponentEvent;
  import info.magnolia.ui.vaadin.gwt.client.shared.AreaElement;
  import info.magnolia.ui.vaadin.gwt.client.shared.ComponentElement;
  import info.magnolia.ui.vaadin.gwt.client.widget.controlbar.ComponentBar;
  import info.magnolia.ui.vaadin.gwt.client.widget.controlbar.listener.ComponentListener;
  
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  
  import com.google.gwt.event.shared.EventBus;
  import com.google.gwt.event.shared.HandlerRegistration;
  
  /**
   * Represents a component inside the {@link CmsNode}-tree.
   * Implements a listener interface for the associated {@link info.magnolia.ui.vaadin.gwt.client.widget.controlbar.ComponentBar}.
   * Handles DnD and move Events for components and provides wrapper functions used by the {@link info.magnolia.ui.vaadin.gwt.client.editor.model.focus.FocusModel}.
   */
  public class MgnlComponent extends MgnlElement implements ComponentListener {
  
      private final EventBus eventBus;
      private List<HandlerRegistration> handlers = new LinkedList<HandlerRegistration>();
  
      public MgnlComponent(MgnlElement parent, EventBus eventBus) {
          super(parent);
          this.eventBus = eventBus;
      }
  
      @Override
      public ComponentElement getTypedElement() {
          ComponentElement component = new ComponentElement(getAttribute("workspace"), getAttribute("path"), getAttribute("dialog"));
          boolean inherited = Boolean.parseBoolean(getAttribute("inherited"));
  
          boolean deletable = true;
          if (getAttributes().containsKey(OperationPermissionDefinition.DELETABLE)) {
              deletable = Boolean.parseBoolean(getAttribute(OperationPermissionDefinition.DELETABLE));
          }
  
          component.setDeletable(deletable && !inherited);
          component.setWritable(hasEditButton());
          component.setMoveable(isMovable());
          return component;
      }
  
      @Override
      public void editComponent() {
          eventBus.fireEvent(new EditComponentEvent(getTypedElement()));
      }
  
      /**
       * Fires a {@link SortComponentEvent} with the parent {@link AreaElement}.
       * Sets the source component this component and the target to the component passed with the {@link ComponentStopMoveEvent}.
       */
      private void sortComponent(MgnlComponent target) {
          MgnlArea area = getParentArea();
          if (area != null) {
              // area.onDragStart(true);
  
              AreaElement areaElement = area.getTypedElement();
              areaElement.setSourceComponent(getTypedElement());
             areaElement.setTargetComponent(target.getTypedElement());
             areaElement.setSortOrder(getSortOrder(target));
 
             SortComponentEvent sortComponentEvent = new SortComponentEvent(areaElement);
             eventBus.fireEvent(sortComponentEvent);
         }
     }
 
     @Override
     public String getLabel() {
         return getAttribute("label");
     }
 
     @Override
     public boolean hasEditButton() {
         boolean inherited = Boolean.parseBoolean(getAttribute("inherited"));
         boolean hasDialog = getAttribute("dialog") != null && getAttribute("dialog") != "";
         boolean writable = true;
         if (getAttributes().containsKey(OperationPermissionDefinition.WRITABLE)) {
             writable = Boolean.parseBoolean(getAttribute(OperationPermissionDefinition.WRITABLE));
         }
         return writable && hasDialog && !inherited;
     }
 
     @Override
     public boolean isMovable() {
         boolean inherited = Boolean.parseBoolean(getAttribute("inherited"));
         MgnlArea parentArea = this.getParentArea();
         boolean parentAreaIsTypeSingle = parentArea != null && "single".equals(parentArea.getAttribute("type"));
         boolean movable = true;
         if (getAttributes().containsKey(OperationPermissionDefinition.MOVEABLE)) {
             movable = Boolean.parseBoolean(getAttribute(OperationPermissionDefinition.MOVEABLE));
         }
         return movable && !inherited && !parentAreaIsTypeSingle;
     }
 
     /**
      * Callback for {@link ComponentBar} when starting a drag or move event. Depending on whether it is a drag or a move
      * it will either notify the server by firing a {@link ComponentStartMoveEvent} or register the handlers in {@link #doStartMove(boolean)}.
      * 
      * @param isDrag whether we are dragging the component or moving it
      */
     @Override
     public void onMoveStart(boolean isDrag) {
         if (isDrag) {
             doStartMove(isDrag);
         } else {
             eventBus.fireEvent(new ComponentStartMoveEvent());
         }
     }
 
     /**
      * Registers the sibling components as move targets and registers a handler for {@link ComponentStopMoveEvent} on the source component which will call {@link #sortComponent(MgnlComponent)}.
      * 
      * @param isDrag whether we are dragging the component or moving it
      */
     public void doStartMove(boolean isDrag) {
         setMoveSource(true);
 
         for (MgnlComponent component : getSiblingComponents()) {
             component.registerMoveTarget(isDrag);
         }
 
         handlers.add(eventBus.addHandler(ComponentStopMoveEvent.TYPE, new ComponentStopMoveEvent.ComponentStopMoveEventHandler() {
             @Override
             public void onStop(ComponentStopMoveEvent componentStopMoveEvent) {
 
                 setMoveSource(false);
 
                 Iterator<HandlerRegistration> it = handlers.iterator();
                 while (it.hasNext()) {
                     it.next().removeHandler();
                     it.remove();
                 }
                 MgnlComponent target = componentStopMoveEvent.getTargetComponent();
                 if (target != null) {
                     sortComponent(target);
                 }
             }
         }));
     }
 
     /**
      * Callback for {@link ComponentBar} targets when a move or drag event is dropped on or moved to this target.
      * Fires {@link ComponentStopMoveEvent} to notify the system. Holds itself as payload for handling by the source,
      * see handler registered in {@link #doStartMove}.
      */
     @Override
     public void onMoveStop() {
         eventBus.fireEvent(new ComponentStopMoveEvent(this, false));
     }
 
     /**
      * Callback for {@link ComponentBar} source when a drag is stopped.
      * Fires {@link ComponentStopMoveEvent} to notify the system about the cancel. Will cause target components to
      * unregister themselves as targets.
      * 
      * @see #unregisterMoveTarget(boolean)
      */
     @Override
     public void onMoveCancel() {
         eventBus.fireEvent(new ComponentStopMoveEvent(null, false));
     }
 
     /**
      * Registers a {@link MgnlComponent} as a target.
      * Registers the ui events for move or DnD on {@link ComponentBar} and adds an handler for {@link ComponentStopMoveEvent}.
      */
     private void registerMoveTarget(final boolean isDrag) {
         setMoveTarget(true);
 
         if (isDrag) {
             registerDragAndDropHandlers();
         } else {
             setDraggable(false);
             registerMoveHandlers();
         }
         handlers.add(eventBus.addHandler(ComponentStopMoveEvent.TYPE, new ComponentStopMoveEvent.ComponentStopMoveEventHandler() {
             @Override
             public void onStop(ComponentStopMoveEvent componentMoveEvent) {
                 unregisterMoveTarget(isDrag);
                 setMoveOver(false);
             }
         }));
     }
 
     /**
      * Unregisters a {@link MgnlComponent} as a target.
      * Removes the ui event handlers for move or DnD on {@link ComponentBar} and removes the handler for {@link ComponentStopMoveEvent}.
      */
     private void unregisterMoveTarget(boolean isDrag) {
         setMoveTarget(false);
 
         if (isDrag) {
             unregisterDragAndDropHandlers();
         } else {
             setDraggable(true);
             unregisterMoveHandlers();
         }
 
         Iterator<HandlerRegistration> it = handlers.iterator();
         while (it.hasNext()) {
             it.next().removeHandler();
             it.remove();
         }
     }
 
     private void registerMoveHandlers() {
         if (getControlBar() != null) {
             getControlBar().registerMoveHandlers();
         }
     }
 
     private void unregisterMoveHandlers() {
         if (getControlBar() != null) {
             getControlBar().unregisterMoveHandlers();
         }
     }
 
     private void registerDragAndDropHandlers() {
         if (getControlBar() != null) {
             getControlBar().registerDragAndDropHandlers();
         }
     }
 
     private void unregisterDragAndDropHandlers() {
         if (getControlBar() != null) {
             getControlBar().unregisterDragAndDropHandlers();
         }
     }
 
     private void setDraggable(boolean draggable) {
         if (getControlBar() != null) {
             getControlBar().setDraggable(draggable);
         }
     }
 
     public void setVisible(boolean visible) {
         if (getControlBar() != null) {
             getControlBar().setVisible(visible);
         }
     }
 
     public void removeFocus() {
         if (getControlBar() != null) {
             getControlBar().removeFocus();
         }
     }
 
     public void setFocus() {
         if (getControlBar() != null) {
             getControlBar().setFocus(false);
         }
     }
 
     public void setMoveTarget(boolean moveTarget) {
         if (getControlBar() != null) {
             getControlBar().setMoveTarget(moveTarget);
         }
     }
 
     public void setMoveOver(boolean moveTarget) {
         if (getControlBar() != null) {
             getControlBar().setMoveOver(moveTarget);
         }
     }
 
     private void setMoveSource(boolean source) {
         if (getControlBar() != null) {
             getControlBar().setMoveSource(source);
         }
     }
 
     @Override
     public ComponentBar getControlBar() {
         return (ComponentBar) super.getControlBar();
     }
 
     private String getSortOrder(MgnlComponent target) {
 
         int xTarget = target.getControlBar().getAbsoluteLeft();
         int yTarget = target.getControlBar().getAbsoluteTop();
         int xThis = getControlBar().getAbsoluteLeft();
         int yThis = getControlBar().getAbsoluteTop();
 
         boolean isDragUp = yThis > yTarget;
         boolean isDragDown = !isDragUp;
         boolean isDragLeft = xThis > xTarget;
         boolean isDragRight = !isDragLeft;
 
         String order = null;
 
         if (isDragUp || isDragLeft) {
             order = "before";
         } else if (isDragDown || isDragRight) {
             order = "after";
         }
         return order;
     }
 
     private List<MgnlComponent> getSiblingComponents() {
         List<MgnlComponent> siblings = new LinkedList<MgnlComponent>();
         MgnlArea area = getParentArea();
         for (MgnlComponent component : area.getComponents()) {
             if (component != this) {
                 siblings.add(component);
             }
         }
         return siblings;
     }
 
     public int getHeight() {
         if (getControlBar() != null) {
             return getControlBar().getOffsetHeight();
         }
         return 0;
     }
 
     public int getWidth() {
         if (getControlBar() != null) {
             return getControlBar().getOffsetWidth();
         }
         return 0;
     }
 }