/**

  * 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;

 import java.io.UnsupportedEncodingException;

 import java.util.ArrayList;

 import java.util.Enumeration;

 import java.util.HashMap;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import javax.servlet.http.HttpServletRequest;

 import org.apache.commons.fileupload.FileItem;

 import org.apache.commons.fileupload.FileUploadException;

 import org.apache.commons.fileupload.disk.DiskFileItemFactory;

 import org.apache.commons.fileupload.servlet.ServletFileUpload;

 import org.apache.commons.lang.ArrayUtils;

 import org.kuali.rice.kew.api.WorkflowRuntimeException;

 /**

  * An abstraction that allows for switching between multipart form requests and normal requests when getting

  * request params

  * 

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

  *

  */

 public class RequestParser {

         private static final String PARSED_MULTI_REQUEST_KEY = "__parsedRequestStruct";

         private static final String UPLOADED_FILES_KEY = "__uploadedFiles";

         public static final String WORKFLOW_DOCUMENT_SESSION_KEY = "workflowDocument";

         public static final String GLOBAL_ERRORS_KEY = "org.kuali.rice.edl.impl.GlobalErrors";

         public static final String GLOBAL_MESSAGES_KEY = "org.kuali.rice.edl.impl.GlobalMessages";

         public static final String GLOBAL_FIELD_ERRORS_KEY = "org.kuali.rice.edl.impl.GlobalFieldErrors";

         private HttpServletRequest request;

         private Map<String, String[]> additionalParameters = new HashMap<String, String[]>();

         public RequestParser(HttpServletRequest request) {

                 this.request = request;

                 // setup empty List of errors and messages

                 request.setAttribute(GLOBAL_ERRORS_KEY, new ArrayList());

                 request.setAttribute(GLOBAL_MESSAGES_KEY, new ArrayList());

                 request.setAttribute(GLOBAL_FIELD_ERRORS_KEY, new HashMap<String, String>());

         }

         private static void parseRequest(HttpServletRequest request) {

                 if (request.getAttribute(PARSED_MULTI_REQUEST_KEY) != null) {

                         return;

                 }

                 Map requestParams = new HashMap();

                 request.setAttribute(PARSED_MULTI_REQUEST_KEY, requestParams);

                 DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();

                 diskFileItemFactory.setSizeThreshold(100);

                 ServletFileUpload upload = new ServletFileUpload(diskFileItemFactory);

                 List items = null;

                 try {

                         items = upload.parseRequest(request);        

                 } catch (FileUploadException fue) {

                         throw new WorkflowRuntimeException(fue);

                 }

                 Iterator iter = items.iterator();

                 while (iter.hasNext()) {

                         try {

                                 FileItem item = (FileItem) iter.next();

                                 if (item.isFormField()) {

                                         String fieldName = item.getFieldName();

                                         String fieldValue = item.getString("utf-8");

                                         String[] paramVals = null;

                                         if (requestParams.containsKey(fieldName)) {

                                                 paramVals = (String[])requestParams.get(fieldName);

                                                 paramVals = (String[]) ArrayUtils.add(paramVals, fieldValue);

                                         } else {

                                                 paramVals = new String[1];

                                                 paramVals[0] = fieldValue;

                                         }

                                         requestParams.put(fieldName, paramVals);

                                 } else {

                                         List uploadedFiles = (List)request.getAttribute(UPLOADED_FILES_KEY);

                                         if (uploadedFiles == null) {

                                                 uploadedFiles = new ArrayList();

                                                 request.setAttribute(UPLOADED_FILES_KEY, uploadedFiles);

                                         }

                                         uploadedFiles.add(item);

                                 }

                         } catch (UnsupportedEncodingException e) {

                                 throw new WorkflowRuntimeException(e);

                         }

                 }

         }

         public String[] getParameterValues(String paramName) {

                 boolean isMultipart = ServletFileUpload.isMultipartContent(this.getRequest());

             String[] params = null;

             if (isMultipart) {

                     parseRequest(this.getRequest());

                     params = (String[]) ((Map)request.getAttribute(PARSED_MULTI_REQUEST_KEY)).get(paramName);

             } else {

                     params = this.getRequest().getParameterValues(paramName);

             }

             if (params == null) {

                     params = additionalParameters.get(paramName);

             }

             return params;

         }

         public void setAttribute(String name, Object value) {

                 this.getRequest().setAttribute(name, value);

         }

         public Object getAttribute(String name) {

                 return this.getRequest().getAttribute(name); 

         }

         public String getParameterValue(String paramName) {

                 String[] paramVals = getParameterValues(paramName);

                 if (paramVals != null) {

                         return paramVals[0];

                 }

                 return null;

         }

         public void setParameterValue(String paramName, String paramValue) {

             additionalParameters.put(paramName, new String[] { paramValue });

         }

         public void setParameterValue(String paramName, String[] paramValue) {

             additionalParameters.put(paramName, paramValue);

         }

         public List<String> getParameterNames() {

             List<String> names = new ArrayList<String>();

             boolean isMultipart = ServletFileUpload.isMultipartContent(this.getRequest());

             if (isMultipart) {

                 parseRequest(this.getRequest());

                 Map paramMap = ((Map)request.getAttribute(PARSED_MULTI_REQUEST_KEY));

                 for (Iterator iterator = paramMap.keySet().iterator(); iterator.hasNext();) {

                     String parameterName = (String)iterator.next();

                     names.add(parameterName);

                 }

             } else { 

                 Enumeration<String> nameEnum = getRequest().getParameterNames();

                 while (nameEnum.hasMoreElements()) {

                     names.add(nameEnum.nextElement());

                 }

             }

             return names;

         }

         public void setRequest(HttpServletRequest request) {

                 this.request = request;

         }

         public HttpServletRequest getRequest() {

                 return request;

         }

         public List getUploadList() {

                 return (List) request.getAttribute(UPLOADED_FILES_KEY);

         }

 }