/**

  * 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.framework.workflow;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.util.xml.XmlException;

 import org.kuali.rice.core.api.util.xml.XmlJotter;

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

 import org.kuali.rice.kew.api.document.DocumentContent;

 import org.kuali.rice.kew.framework.postprocessor.ActionTakenEvent;

 import org.kuali.rice.kew.framework.postprocessor.DeleteEvent;

 import org.kuali.rice.kew.framework.postprocessor.DocumentRouteLevelChange;

 import org.kuali.rice.kew.framework.postprocessor.DocumentRouteStatusChange;

 import org.kuali.rice.kew.framework.postprocessor.ProcessDocReport;

 import org.kuali.rice.kew.postprocessor.DefaultPostProcessor;

 import org.w3c.dom.Document;

 import org.w3c.dom.Element;

 import org.xml.sax.InputSource;

 import javax.xml.parsers.DocumentBuilder;

 import javax.xml.parsers.DocumentBuilderFactory;

 import javax.xml.xpath.XPath;

 import javax.xml.xpath.XPathConstants;

 import javax.xml.xpath.XPathExpressionException;

 import javax.xml.xpath.XPathFactory;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InterruptedIOException;

 import java.io.OutputStream;

 import java.io.StringReader;

 import java.lang.reflect.Method;

 import java.net.Socket;

 import java.net.URL;

 import java.rmi.RemoteException;

 import java.util.Timer;

 import java.util.TimerTask;

 /**

  * PostProcessor responsible for posting events to a url defined in the EDL doc definition.

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

  */

 public class EDocLitePostProcessor extends DefaultPostProcessor {

     private static final Logger LOG = Logger.getLogger(EDocLitePostProcessor.class);

     private static final Timer TIMER = new Timer();

     public static final int SUBMIT_URL_MILLISECONDS_WAIT = 60000;

     public static final String EVENT_TYPE_ACTION_TAKEN = "actionTaken";

     public static final String EVENT_TYPE_DELETE_ROUTE_HEADER = "deleteRouteHeader";

     public static final String EVENT_TYPE_ROUTE_LEVEL_CHANGE = "routeLevelChange";

     public static final String EVENT_TYPE_ROUTE_STATUS_CHANGE = "statusChange";

     private static String getURL(Document edlDoc) throws XPathExpressionException {

         XPath xpath = XPathFactory.newInstance().newXPath();

         return (String) xpath.evaluate("//edlContent/edl/eventNotificationURL", edlDoc, XPathConstants.STRING);

     }

     /**

      * @param urlstring

      * @param eventDoc

      */

     private static void submitURL(String urlstring, Document eventDoc) throws IOException {

         String content;

         try {

             content = XmlJotter.jotNode(eventDoc, true);

         } catch (XmlException te) {

             LOG.error("Error writing serializing event doc: " + eventDoc);

             throw te;

         }

         byte[] contentBytes = content.getBytes("UTF-8");

         LOG.debug("submitURL: " + urlstring);

         URL url = new URL(urlstring);

         String message = "POST " + url.getFile() + " HTTP/1.0\r\n" +

                          "Content-Length: " + contentBytes.length + "\r\n" +

                          "Cache-Control: no-cache\r\n" +

                          "Pragma: no-cache\r\n" +

                          "User-Agent: Java/1.4.2; EDocLitePostProcessor\r\n" +

                          "Host: " + url.getHost() + "\r\n" +

                          "Connection: close\r\n" +

                          "Content-Type: application/x-www-form-urlencoded\r\n\r\n" +

                          content;

         byte[] buf = message.getBytes("UTF-8");

         Socket s = new Socket(url.getHost(), url.getPort());

         /*URLConnection con = url.openConnection();

         LOG.debug("got connection: " + con);

         con.setDoOutput(true);

         con.setDoInput(true);

         LOG.debug("setDoOutput(true)");

         con.setRequestProperty("Connection", "close");

         con.setRequestProperty("Content-Length", String.valueOf(buf.length));*/

         OutputStream os = s.getOutputStream();

         try {

             try {

                 os.write(buf, 0, buf.length);

                 os.flush();

             } catch (InterruptedIOException ioe) {

                 LOG.error("IO was interrupted while posting event to url " + urlstring + ": " + ioe.getMessage());

             } catch (IOException ioe) {

                 LOG.error("Error posting EDocLite content to url " + urlstring + ioe.getMessage());

             } finally {

                 try {

                     LOG.debug("Shutting down output stream");

                     s.shutdownOutput();

                 } catch (IOException ioe) {

                     LOG.error("Error shutting down output stream for url " + urlstring + ": " + ioe.getMessage());

                 }

             }

             InputStream is = s.getInputStream();

             try {

                 buf = new byte[1024];

                 ByteArrayOutputStream baos = new ByteArrayOutputStream();

                 // this is what actually forces the write on the URLConnection!

                 int read = is.read(buf);

                 if (read != -1) {

                     baos.write(buf, 0, read);

                 }

                 LOG.debug("EDocLite post processor response:\n" + new String(baos.toByteArray()));

             } catch (InterruptedIOException ioe) {

                 LOG.error("IO was interrupted while reading response from url " + urlstring + ": " + ioe.getMessage());

             } catch (IOException ioe) {

                 LOG.error("Error reading response from EDocLite handler url " + urlstring + ioe.getMessage());

             } finally {

                 try {

                     LOG.debug("Shutting down input stream");

                     s.shutdownInput();

                 } catch (IOException ioe) {

                     LOG.error("Error shutting down input stream for url " + urlstring + ": " + ioe.getMessage());

                 }

             }

         } finally {

             try {

                 s.close();

             } catch (IOException ioe) {

                 LOG.error("Error closing socket", ioe);

             }

         }

     }

     protected static void postEvent(String docId, Object event, String eventName) {

             try {

                     Document doc = getEDLContent(docId);

                     if(LOG.isDebugEnabled()){

                             LOG.debug("Submitting doc: " + XmlJotter.jotNode(doc));

                     }

                     String urlstring = getURL(doc);

                     if (org.apache.commons.lang.StringUtils.isEmpty(urlstring)) {

                             LOG.warn("No eventNotificationURL defined in EDLContent");

                             return;

                     }

                     Document eventDoc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

                     Element eventE = eventDoc.createElement("event");

                     eventE.setAttribute("type", eventName);

                     eventDoc.appendChild(eventE);

                     Element infoE = (Element) eventDoc.importNode(propertiesToXml(event, "info"), true);

                     Element docIdE = eventDoc.createElement("docId");

                     docIdE.appendChild(eventDoc.createTextNode(String.valueOf(docId)));

                     infoE.appendChild(docIdE);

                     eventE.appendChild(infoE);

                     eventE.appendChild(eventDoc.importNode(doc.getDocumentElement(), true));

                     String query = "docId=" + docId;

                     if (urlstring.indexOf('?') != -1) {

                             urlstring += "&" + query;

                     } else {

                             urlstring += "?" + query;

                     }

                     final String _urlstring = urlstring;

                     final Document _eventDoc = eventDoc;

                     // a super cheesy way to enforce asynchronicity/timeout follows:

                     final Thread t = new Thread(new Runnable() {

                             public void run() {

                                     try {

                                             LOG.debug("Post Event calling url: " + _urlstring);

                                             submitURL(_urlstring, _eventDoc);

                                             LOG.debug("Post Event done calling url: " + _urlstring);

                                     } catch (Exception e) {

                                             LOG.error(e);

                                     }

                             }

                     });

                     t.setDaemon(true);

                     t.start();

                     // kill the submission thread if it hasn't completed after 1 minute

                     TIMER.schedule(new TimerTask() {

                             public void run() {

                                     t.interrupt();

                             }

                     }, SUBMIT_URL_MILLISECONDS_WAIT);

             } catch (Exception e) {

                     if (e instanceof RuntimeException) {

                             throw (RuntimeException)e;

                     }

                     throw new RuntimeException(e);

             }

     }

     public ProcessDocReport doRouteStatusChange(DocumentRouteStatusChange event) throws RemoteException {

         LOG.debug("doRouteStatusChange: " + event);

         postEvent(event.getDocumentId(), event, EVENT_TYPE_ROUTE_STATUS_CHANGE);

         return new ProcessDocReport(true, "");

     }

     public ProcessDocReport doActionTaken(ActionTakenEvent event) throws RemoteException {

         LOG.debug("doActionTaken: " + event);

         postEvent(event.getDocumentId(), event, EVENT_TYPE_ACTION_TAKEN);

         return new ProcessDocReport(true, "");

     }

     public ProcessDocReport doDeleteRouteHeader(DeleteEvent event) throws RemoteException {

         LOG.debug("doDeleteRouteHeader: " + event);

         postEvent(event.getDocumentId(), event, EVENT_TYPE_DELETE_ROUTE_HEADER);

         return new ProcessDocReport(true, "");

     }

     public ProcessDocReport doRouteLevelChange(DocumentRouteLevelChange event) throws RemoteException {

         LOG.debug("doRouteLevelChange: " + event);

         postEvent(event.getDocumentId(), event, EVENT_TYPE_ROUTE_LEVEL_CHANGE);

         return new ProcessDocReport(true, "");

     }

     public static Document getEDLContent(String documentId) {

             try {

                     DocumentContent documentContent = KewApiServiceLocator.getWorkflowDocumentService().getDocumentContent(documentId);

                     String content = documentContent.getFullContent();

                     Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new InputSource(new StringReader(content)));

                     return doc;

             } catch (Exception e) {

                     if (e instanceof RuntimeException) {

                             throw (RuntimeException)e;

                     }

                     throw new RuntimeException(e);

             }

     }

     public static DocumentBuilder getDocumentBuilder() throws Exception {

         return DocumentBuilderFactory.newInstance().newDocumentBuilder();

     }

     private static String lowerCaseFirstChar(String s) {

         if (s.length() == 0 || Character.isLowerCase(s.charAt(0)))

             return s;

         StringBuffer sb = new StringBuffer(s.length());

         sb.append(Character.toLowerCase(s.charAt(0)));

         if (s.length() > 1) {

             sb.append(s.substring(1));

         }

         return sb.toString();

     }

     public static Element propertiesToXml(Object o, String elementName) throws Exception {

         Class c = o.getClass();

         Document doc = getDocumentBuilder().newDocument();

         Element wrapper = doc.createElement(elementName);

         Method[] methods = c.getMethods();

         for (int i = 0; i < methods.length; i++) {

             String name = methods[i].getName();

             if ("getClass".equals(name))

                 continue;

             if (!name.startsWith("get") || methods[i].getParameterTypes().length > 0)

                 continue;

             name = name.substring("get".length());

             name = lowerCaseFirstChar(name);

             String value = null;

             try {

                 Object result = methods[i].invoke(o, null);

                 if (result == null) {

                     LOG.debug("value of " + name + " method on object " + o.getClass() + " is null");

                     value = "";

                 } else {

                     value = result.toString();

                 }

                 Element fieldE = doc.createElement(name);

                 fieldE.appendChild(doc.createTextNode(value));

                 wrapper.appendChild(fieldE);

             } catch (RuntimeException e) {

                 LOG.error("Error accessing method '" + methods[i].getName() + " of instance of " + c);

                 throw e;

             } catch (Exception e) {

                 LOG.error("Error accessing method '" + methods[i].getName() + " of instance of " + c);

             }

         }

         return wrapper;

     }

 }