/**
    * Copyright 2005-2011 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.edl.impl.components;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.edl.impl.EDLContext;
  import org.kuali.rice.edl.impl.EDLModelComponent;
  import org.kuali.rice.edl.impl.RequestParser;
  import org.kuali.rice.edl.impl.UserAction;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.NodeList;
  
  public class RefreshFromLookupComponent implements EDLModelComponent {
  	
  	public void updateDOM(Document dom, Element configElement, EDLContext edlContext) {
  		String command = edlContext.getUserAction().getAction();
  		if (UserAction.ACTION_REFRESH_FROM_LOOKUP.equals(command)) {
  			RequestParser requestParser = edlContext.getRequestParser();
  			
  			Element currentVersion = VersioningPreprocessor.findCurrentVersion(dom);
  			// First, create a list of all of the <field> tags that match the parameter names returned from the lookup
  			List<Element> fieldsToDelete = new ArrayList<Element>();
  			NodeList fieldNodes = currentVersion.getElementsByTagName("field");
  			
  			// get the list of input parameters returned from the lookup so we can clear empty ones as well
  			List<String> requestParameterNames = requestParser.getParameterNames();
  			
  			for (int i = 0; i < fieldNodes.getLength(); i++) {
  				Element fieldNode = (Element) fieldNodes.item(i);
  				String fieldName = fieldNode.getAttribute("name");
  				if (requestParameterNames.contains(fieldName)) {
  					fieldsToDelete.add(fieldNode);
  				}
  			}
  			
  			// Second, delete those nodes; we will rely on normal population to recreate those nodes
  			// if the nodes weren't deleted, EDL would continue to display the old value on the generated output
  			for (Element fieldToDelete : fieldsToDelete) {
  				currentVersion.removeChild(fieldToDelete);
  			}
  		}
  	}
  }