/*
    * Copyright 2007-2008 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.kew.export;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.kuali.rice.core.api.CoreApiServiceLocator;
  import org.kuali.rice.core.api.impex.ExportDataSet;
  import org.kuali.rice.kew.doctype.bo.DocumentType;
  import org.kuali.rice.kew.help.HelpEntry;
  import org.kuali.rice.kew.rule.RuleBaseValues;
  import org.kuali.rice.kew.rule.RuleDelegation;
  import org.kuali.rice.kew.rule.bo.RuleAttribute;
  import org.kuali.rice.kew.rule.bo.RuleTemplate;
  import org.kuali.rice.kim.api.group.Group;
  import org.kuali.rice.kim.impl.group.GroupBo;
  import org.kuali.rice.krad.bo.Exporter;
  import org.kuali.rice.krad.exception.ExportNotSupportedException;
  import org.kuali.rice.krad.util.KRADConstants;
  
  /**
   * The DataExporter allows for exporting of KEW BusinessObjects to various
   * supported formats. The current implementation supports only XML export. This
   * process is initiated from the KNS screens (lookups and inquiries) and this
   * implementation leverages the existing XmlExporterService which is part of KEW
   * and which was used to do exports before KEW was converted to use the KNS.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class DataExporter implements Exporter {
  
  	private List<String> supportedFormats = new ArrayList<String>();
  
  	public DataExporter() {
  		supportedFormats.add(KRADConstants.XML_FORMAT);
  	}
  
  	/**
  	 * @see org.kuali.rice.krad.bo.Exporter#getSupportedFormats(java.lang.Class)
  	 */
  	@Override
  	public List<String> getSupportedFormats(Class<?> dataObjectClass) {
  		return supportedFormats;
  	}
  
  	/**
  	 * Builds the ExportDataSet based on the BusinessObjects passed in.
  	 */
  	protected ExportDataSet buildExportDataSet(Class<?> dataObjectClass, List<? extends Object> dataObjects) {
  		KewExportDataSet dataSet = new KewExportDataSet();
  		for (Object dataObject : dataObjects) {
  			if (dataObjectClass.equals(RuleAttribute.class)) {
  				dataSet.getRuleAttributes().add((RuleAttribute)dataObject);
  			} else if (dataObjectClass.equals(RuleTemplate.class)) {
  				dataSet.getRuleTemplates().add((RuleTemplate)dataObject);
  			} else if (dataObjectClass.equals(DocumentType.class)) {
  				dataSet.getDocumentTypes().add((DocumentType)dataObject);
  			} else if (dataObjectClass.equals(HelpEntry.class)) {
  				dataSet.getHelp().add((HelpEntry)dataObject);
  			} else if (dataObjectClass.equals(RuleBaseValues.class)) {
  				dataSet.getRules().add((RuleBaseValues)dataObject);
  			} else if (dataObjectClass.equals(RuleDelegation.class)) {
  				dataSet.getRuleDelegations().add((RuleDelegation)dataObject);
  			} else if (dataObjectClass.equals(GroupBo.class)) {
  				dataSet.getGroups().add((Group)dataObject);
  			}
  		}
  
  		ExportDataSet exportDataSet = new ExportDataSet();
  		dataSet.populateExportDataSet(exportDataSet);
  		return exportDataSet;
  	}
  
  	/**
  	 * Export the given List of Objects of the specified type to XML.
  	 * 
  	 * @see org.kuali.rice.krad.bo.Exporter#export(java.lang.Class, java.util.List, java.lang.String, java.io.OutputStream)
  	 */
  	@Override
  	public void export(Class<?> dataObjectClass, List<? extends Object> dataObjects, String exportFormat, OutputStream outputStream) throws IOException,
  			ExportNotSupportedException {
  		if (!KRADConstants.XML_FORMAT.equals(exportFormat)) {
  			throw new ExportNotSupportedException("The given export format of "
 					+ exportFormat
 					+ " is not supported by the KEW XML Exporter!");
 		}
 		ExportDataSet dataSet = buildExportDataSet(dataObjectClass, dataObjects);
 		outputStream.write(CoreApiServiceLocator.getXmlExporterService()
 				.export(dataSet));
 		outputStream.flush();
 		
 	}
 }