/*
    * 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.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import javax.jcr.Node;
  
  import org.argeo.cms.ui.jcr.model.SingleJcrNodeElem;
  import org.argeo.cms.ui.jcr.model.WorkspaceElem;
  import org.argeo.cms.ui.workbench.WorkbenchUiPlugin;
  import org.argeo.eclipse.ui.dialogs.ErrorFeedback;
  import org.argeo.jcr.JcrUtils;
  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.swt.widgets.Shell;
  import org.eclipse.ui.handlers.HandlerUtil;
  
  /** Compute an approximative size for the selected node(s) */
  public class GetNodeSize extends AbstractHandler {
  	// private final static Log log = LogFactory.getLog(GetNodeSize.class);
  
  	public final static String ID = WorkbenchUiPlugin.PLUGIN_ID + ".getNodeSize";
  
  	public Object execute(ExecutionEvent event) throws ExecutionException {
  
  		ISelection selection = HandlerUtil.getActiveWorkbenchWindow(event)
  				.getActivePage().getSelection();
  
  		if (selection != null && !selection.isEmpty()
  				&& selection instanceof IStructuredSelection) {
  
  			long size = 0;
  
  			Iterator<?> it = ((IStructuredSelection) selection).iterator();
  
  			// TODO enhance this: as the size method is recursive, we keep track
  			// of nodes for which we already have computed size so that we don't
  			// count them twice. In a first approximation, we assume that the
  			// structure selection keep the nodes ordered.
  			List<String> importedPathes = new ArrayList<String>();
  			try {
  				nodesIt: while (it.hasNext()) {
  					Object obj = it.next();
  					String curPath;
  					Node node;
  					if (obj instanceof SingleJcrNodeElem) {
  						node = ((SingleJcrNodeElem) obj).getNode();
  						curPath = node.getSession().getWorkspace().getName();
  						curPath += "/" + node.getPath();
  					} else if (obj instanceof WorkspaceElem) {
  						node = ((WorkspaceElem) obj).getRootNode();
  						curPath = node.getSession().getWorkspace().getName();
  					} else
  						// non valid object type
  						continue nodesIt;
  
  					Iterator<String> itPath = importedPathes.iterator();
  					while (itPath.hasNext()) {
  						String refPath = itPath.next();
  						if (curPath.startsWith(refPath))
  							// Already done : skip node
  							continue nodesIt;
  					}
  					size += JcrUtils.getNodeApproxSize(node);
  					importedPathes.add(curPath);
  				}
  			} catch (Exception e) {
  				ErrorFeedback.show("Cannot Get size of selected node ", e);
  			}
  
  			String[] labels = { "OK" };
  			Shell shell = HandlerUtil.getActiveWorkbenchWindow(event)
  					.getShell();
  			MessageDialog md = new MessageDialog(shell, "Node size", null,
  					"Node size is: " + size / 1024 + " KB",
  					MessageDialog.INFORMATION, labels, 0);
  			md.open();
  		}
  		return null;
 	}
 }