/**
    * 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.IOException;
  
  import javax.servlet.RequestDispatcher;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.edl.impl.service.EdlServiceLocator;
  import org.kuali.rice.kew.api.WorkflowRuntimeException;
  import org.kuali.rice.kns.util.IncidentReportUtils;
  import org.kuali.rice.krad.UserSession;
  import org.kuali.rice.krad.exception.AuthenticationException;
  import org.kuali.rice.krad.util.GlobalVariables;
  import org.kuali.rice.krad.util.KRADConstants;
  import org.kuali.rice.krad.util.KRADUtils;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  
  
  /**
   * Takes edl web requests.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   *
   */
  public class EDLServlet extends HttpServlet {
  
  	private static final long serialVersionUID = -6344765194278430690L;
  
  	private static final Logger LOG = Logger.getLogger(EDLServlet.class);
  
  	@Override
  	public void init() throws ServletException {
  		try {
  			EdlServiceLocator.getEDocLiteService().initEDLGlobalConfig();
  		} catch (Exception e) {
  			LOG.error("Error initializing EDL", e);
  		}
  
  	}
  
  	@Override
  	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  		String documentId = null;
  		try {
  		    UserSession userSession = KRADUtils.getUserSessionFromRequest(request);
  		    if (userSession == null) {
  		        throw new AuthenticationException("Failed to locate a user session for request.");
  		    }
  		    GlobalVariables.setUserSession(userSession);
  		    
  		    RequestParser requestParser = new RequestParser(request);
  		    String inputCommand = requestParser.getParameterValue("command");
  		    if (StringUtils.equals(inputCommand, "initiate")){
  		    	requestParser.setParameterValue("userAction","initiate");
  		    }
  		    String edlName = requestParser.getParameterValue("edlName");
  		    if (edlName == null) {
  		        edlName = requestParser.getParameterValue("docTypeName");//this is for 'WorkflowQuicklinks'
  		    }
  		    EDLController edlController = null;
  		    
  		    if (edlName == null) {
  		        documentId = requestParser.getParameterValue("docId");
  		        if (documentId == null) {
  		        	String docFormKey = requestParser.getParameterValue(KRADConstants.DOC_FORM_KEY);
  		        	if (docFormKey != null) {
  		        		Document document = (Document) GlobalVariables.getUserSession().retrieveObject(docFormKey);
  		        		Element documentState = EDLXmlUtils.getDocumentStateElement(document);
  		        		documentId = EDLXmlUtils.getChildElementTextValue(documentState, "docId");
  		        		requestParser.setAttribute(KRADConstants.DOC_FORM_KEY, docFormKey);
  		        	}
  		        	if (documentId == null) {
  		        		throw new WorkflowRuntimeException("No edl name or document id detected");
  		        	}
  		        }
  		        requestParser.setAttribute("docId", documentId);
  		        edlController = EdlServiceLocator.getEDocLiteService().getEDLControllerUsingDocumentId(documentId);
  		    } else {
 		        edlController = EdlServiceLocator.getEDocLiteService().getEDLControllerUsingEdlName(edlName);
 		    }
 
 		    //TODO Fix this in a better way (reworking the command structure maybe?)
 		    //fix for KULRICE-4057 to make sure we don't destory docContent on empty command params
 		    if(inputCommand == null && requestParser.getParameterValue("docId") != null && !"POST".equals(request.getMethod())){
 		    	//make sure these are the only params on the request (paging passed undefined input command as well...
 		    	if(!(request.getParameterMap().size() > 2)){//ensures ONLY documentId was passed
 		    		requestParser.setParameterValue("command", "displayDocSearchView");
 		    		LOG.info("command parameter was not passed with the request, and only document ID was. Defaulted command to 'displayDocSearchView' to ensure docContent remains.");
 		    	}
 		    }
 
 		    EDLControllerChain controllerChain = new EDLControllerChain();
 		    controllerChain.addEdlController(edlController);
 			//TODO Do we not want to set the content type for the response?		   
 		    controllerChain.renderEDL(requestParser, response);
 
 		} catch (Exception e) {
 			LOG.error("Error processing EDL", e);
 			outputError(request, response, e, documentId);
 		} finally {
 		    GlobalVariables.setUserSession(null);
 		}
 	}
 
 	private void outputError(HttpServletRequest request, HttpServletResponse response, Exception exception, String documentId) throws ServletException, IOException {
 			IncidentReportUtils.populateRequestForIncidentReport(exception, "" + documentId, "eDoc Lite", request);
 	        RequestDispatcher rd = getServletContext().getRequestDispatcher(request.getServletPath() + "/../../kr/kualiExceptionIncidentReport.do");
 	        rd.forward(request, response);
 	}
 
 }