/*

  * 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.kns.lookup;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.io.Writer;

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.commons.io.output.WriterOutputStream;

 import org.apache.commons.lang.StringUtils;

 import org.displaytag.model.Row;

 import org.displaytag.model.TableModel;

 import org.kuali.rice.kns.bo.BusinessObject;

 import org.kuali.rice.kns.bo.Exporter;

 import org.kuali.rice.kns.datadictionary.BusinessObjectEntry;

 import org.kuali.rice.kns.service.KNSServiceLocatorWeb;

 import org.kuali.rice.kns.exception.ExportNotSupportedException;

 import org.kuali.rice.kns.util.GlobalVariables;

 import org.kuali.rice.kns.web.struts.form.KualiForm;

 import org.kuali.rice.kns.web.struts.form.LookupForm;

 import org.kuali.rice.kns.web.ui.ResultRow;

 /**

  * A helper class to be used with the custom ExportView implementations for

  * Display Tag.  Most of the logic for interfacing with the KNS export

  * system is encapsulated in this helper class so it can be shared between

  * the various Display Tag export implementations. 

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class ExportViewHelper {

         private BusinessObjectEntry businessObjectEntry;

         private List<BusinessObject> businessObjects;

         public ExportViewHelper(TableModel tableModel) {

                 this.businessObjectEntry = loadBusinessObjectEntry();

                 this.businessObjects = loadBusinessObjects(tableModel);

         }

         protected BusinessObjectEntry loadBusinessObjectEntry() {

                 KualiForm kualiForm = GlobalVariables.getKualiForm();

                 if (kualiForm instanceof LookupForm) {

                         LookupForm lookupForm = (LookupForm) kualiForm;

                         if (!StringUtils.isBlank(lookupForm.getBusinessObjectClassName())) {

                                 return KNSServiceLocatorWeb.getDataDictionaryService().getDataDictionary().getBusinessObjectEntry(lookupForm.getBusinessObjectClassName());

                         }

                 }

                 return null;

         }

         protected List<BusinessObject> loadBusinessObjects(TableModel tableModel) {

                 List<BusinessObject> businessObjects = new ArrayList<BusinessObject>();

                 List<Row> rowList = tableModel.getRowListFull();

                 for (Row row : rowList) {

                         ResultRow resultRow = (ResultRow)row.getObject();

                         if (resultRow.getBusinessObject() != null) {

                                 businessObjects.add(resultRow.getBusinessObject());

                         }

                 }

                 return businessObjects;

         }

         public BusinessObjectEntry getBusinessObjectEntry() {

                 return businessObjectEntry;

         }

         public List<BusinessObject> getBusinessObjects() {

                 return businessObjects;

         }

         public boolean attemptCustomExport(OutputStream outputStream, String exportFormat) throws IOException {

                 if (getBusinessObjectEntry() != null && getBusinessObjectEntry().getExporterClass() != null) {

                         final Exporter exporter;

                         try {

                                 exporter = getBusinessObjectEntry().getExporterClass().newInstance();

                         } catch (Exception e) {

                                 throw new ExportNotSupportedException("Failed to load export class: " + businessObjectEntry.getExporterClass(),e);

                         }

                         List<String> supportedFormats = exporter.getSupportedFormats(businessObjectEntry.getBusinessObjectClass());

                         if (supportedFormats.contains(exportFormat)) {

                                 exporter.export(businessObjectEntry.getBusinessObjectClass(), getBusinessObjects(), exportFormat, outputStream);

                                 return true;

                         }

                 }

                 return false;

         }

         public boolean attemptCustomExport(Writer writer, String exportFormat) throws IOException {

                 return attemptCustomExport(new WriterOutputStream(writer), exportFormat);

         }

 }