/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *         http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.argeo.cms.ui.workbench.internal.jcr.commands;
  
  import java.util.Iterator;
  
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.argeo.cms.ui.jcr.model.SingleJcrNodeElem;
  import org.argeo.cms.ui.jcr.model.WorkspaceElem;
  import org.argeo.cms.ui.workbench.jcr.JcrBrowserView;
  import org.argeo.eclipse.ui.EclipseUiException;
  import org.argeo.eclipse.ui.TreeParent;
  import org.argeo.eclipse.ui.dialogs.ErrorFeedback;
  import org.eclipse.core.commands.AbstractHandler;
  import org.eclipse.core.commands.ExecutionEvent;
  import org.eclipse.core.commands.ExecutionException;
  import org.eclipse.jface.dialogs.MessageDialog;
  import org.eclipse.jface.viewers.ISelection;
  import org.eclipse.jface.viewers.IStructuredSelection;
  import org.eclipse.ui.handlers.HandlerUtil;
  
  /**
   * Delete the selected nodes: both in the JCR repository and in the UI view.
   * Warning no check is done, except implementation dependent native checks,
   * handle with care.
   * 
   * This handler is still 'hard linked' to a GenericJcrBrowser view to enable
   * correct tree refresh when a node is added. This must be corrected in future
   * versions.
   */
  public class DeleteNodes extends AbstractHandler {
  	public Object execute(ExecutionEvent event) throws ExecutionException {
  		ISelection selection = HandlerUtil.getActiveWorkbenchWindow(event)
  				.getActivePage().getSelection();
  		if (selection == null || !(selection instanceof IStructuredSelection))
  			return null;
  
  		JcrBrowserView view = (JcrBrowserView) HandlerUtil
  				.getActiveWorkbenchWindow(event).getActivePage()
  				.findView(HandlerUtil.getActivePartId(event));
  
  		// confirmation
  		StringBuffer buf = new StringBuffer("");
  		Iterator<?> lst = ((IStructuredSelection) selection).iterator();
  		while (lst.hasNext()) {
  			SingleJcrNodeElem sjn = ((SingleJcrNodeElem) lst.next());
  			buf.append(sjn.getName()).append(' ');
  		}
  		Boolean doRemove = MessageDialog.openConfirm(
  				HandlerUtil.getActiveShell(event), "Confirm deletion",
  				"Do you want to delete " + buf + "?");
  
  		// operation
  		if (doRemove) {
  			Iterator<?> it = ((IStructuredSelection) selection).iterator();
  			Object obj = null;
  			SingleJcrNodeElem ancestor = null;
  			WorkspaceElem rootAncestor = null;
  			try {
  				while (it.hasNext()) {
  					obj = it.next();
  					if (obj instanceof SingleJcrNodeElem) {
  						// Cache objects
  						SingleJcrNodeElem sjn = (SingleJcrNodeElem) obj;
  						TreeParent tp = (TreeParent) sjn.getParent();
  						Node node = sjn.getNode();
  
  						// Jcr Remove
  						node.remove();
  						node.getSession().save();
  						// UI remove
  						tp.removeChild(sjn);
  
  						// Check if the parent is the root node
  						if (tp instanceof WorkspaceElem)
  							rootAncestor = (WorkspaceElem) tp;
  						else
  							ancestor = getOlder(ancestor, (SingleJcrNodeElem) tp);
  					}
  				}
  				if (rootAncestor != null)
  					view.nodeRemoved(rootAncestor);
  				else if (ancestor != null)
  					view.nodeRemoved(ancestor);
 			} catch (Exception e) {
 				ErrorFeedback.show("Cannot delete selected node ", e);
 			}
 		}
 		return null;
 	}
 
 	private SingleJcrNodeElem getOlder(SingleJcrNodeElem A, SingleJcrNodeElem B) {
 		try {
 			if (A == null)
 				return B == null ? null : B;
 			// Todo enhanced this method
 			else
 				return A.getNode().getDepth() <= B.getNode().getDepth() ? A : B;
 		} catch (RepositoryException re) {
 			throw new EclipseUiException("Cannot find ancestor", re);
 		}
 	}
 }