/*
    * 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.jcr;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  import javax.jcr.nodetype.NodeType;
  import javax.jcr.version.Version;
  import javax.jcr.version.VersionHistory;
  import javax.jcr.version.VersionIterator;
  import javax.jcr.version.VersionManager;
  
  import org.argeo.eclipse.ui.EclipseUiException;
  import org.eclipse.jface.viewers.ITreeContentProvider;
  import org.eclipse.jface.viewers.Viewer;
  
  /**
   * Display some version information of a JCR full versionable node in a tree
   * like structure
   */
  public class FullVersioningTreeContentProvider implements ITreeContentProvider {
  	private static final long serialVersionUID = 8691772509491211112L;
  
  	/**
  	 * Sends back the first level of the Tree. input element must be a single
  	 * node object
  	 */
  	public Object[] getElements(Object inputElement) {
  		try {
  			Node rootNode = (Node) inputElement;
  			String curPath = rootNode.getPath();
  			VersionManager vm = rootNode.getSession().getWorkspace()
  					.getVersionManager();
  
  			VersionHistory vh = vm.getVersionHistory(curPath);
  			List<Version> result = new ArrayList<Version>();
  			VersionIterator vi = vh.getAllLinearVersions();
  
  			while (vi.hasNext()) {
  				result.add(vi.nextVersion());
  			}
  			return result.toArray();
  		} catch (RepositoryException re) {
  			throw new EclipseUiException(
  					"Unexpected error while getting version elements", re);
  		}
  	}
  
  	public Object[] getChildren(Object parentElement) {
  		try {
  			if (parentElement instanceof Version) {
  				List<Node> tmp = new ArrayList<Node>();
  				tmp.add(((Version) parentElement).getFrozenNode());
  				return tmp.toArray();
  			}
  		} catch (RepositoryException re) {
  			throw new EclipseUiException("Unexpected error while getting child "
  					+ "node for version element", re);
  		}
  		return null;
  	}
  
  	public Object getParent(Object element) {
  		try {
  			// this will not work in a simpleVersionning environment, parent is
  			// not a node.
  			if (element instanceof Node
  					&& ((Node) element).isNodeType(NodeType.NT_FROZEN_NODE)) {
  				Node node = (Node) element;
  				return node.getParent();
  			} else
  				return null;
  		} catch (RepositoryException e) {
  			return null;
  		}
  	}
  
  	public boolean hasChildren(Object element) {
  		try {
  			if (element instanceof Version)
  				return true;
  			else if (element instanceof Node)
  				return ((Node) element).hasNodes();
 			else
 				return false;
 		} catch (RepositoryException e) {
 			throw new EclipseUiException("Cannot check children of " + element, e);
 		}
 	}
 
 	public void dispose() {
 	}
 
 	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 	}
 
 }