/**
    * Waffle (https://github.com/dblock/waffle)
    *
    * Copyright (c) 2010 - 2015 Application Security, Inc.
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *     Application Security, Inc.
   */
  package waffle.servlet;
  
  import java.io.IOException;
  import java.security.Principal;
  import java.util.Enumeration;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.transform.OutputKeys;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerConfigurationException;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  
  import waffle.util.WaffleInfo;
  
  /**
   * A servlet that returns WaffleInfo as XML.
   */
  public class WaffleInfoServlet extends HttpServlet {
  
      /** The Constant serialVersionUID. */
      private static final long serialVersionUID = 1L;
  
      /*
       * (non-Javadoc)
       * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
       * javax.servlet.http.HttpServletResponse)
       */
      @Override
      public void doGet(final HttpServletRequest request, final HttpServletResponse response) throws ServletException,
              IOException {
          this.getWaffleInfoResponse(request, response);
      }
  
      /*
       * (non-Javadoc)
       * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
       * javax.servlet.http.HttpServletResponse)
       */
      @Override
      public void doPost(final HttpServletRequest request, final HttpServletResponse response) throws ServletException,
              IOException {
          this.getWaffleInfoResponse(request, response);
      }
  
      /**
       * Gets the waffle info response.
       *
       * @param request
       *            the request
       * @param response
       *            the response
       * @throws IOException
       *             Signals that an I/O exception has occurred.
       * @throws ServletException
       *             the servlet exception
       */
      public void getWaffleInfoResponse(final HttpServletRequest request, final HttpServletResponse response)
              throws IOException, ServletException {
          final WaffleInfo info = new WaffleInfo();
          try {
              final Document doc = info.getWaffleInfo();
              final Element root = doc.getDocumentElement();
  
              // Add the Request Information Here
              final Element http = this.getRequestInfo(doc, request);
              root.insertBefore(http, root.getFirstChild());
  
              // Lookup Accounts By Name
              final String[] lookup = request.getParameterValues("lookup");
              if (lookup != null) {
                  for (final String name : lookup) {
                      root.appendChild(info.getLookupInfo(doc, name));
                  }
              }
  
              // Write the XML Response
             final TransformerFactory transfac = TransformerFactory.newInstance();
             final Transformer trans = transfac.newTransformer();
             trans.setOutputProperty(OutputKeys.INDENT, "yes");
 
             final StreamResult result = new StreamResult(response.getWriter());
             final DOMSource source = new DOMSource(doc);
             trans.transform(source, result);
             response.setContentType("application/xml");
         } catch (final ParserConfigurationException e) {
             throw new ServletException(e);
         } catch (final TransformerConfigurationException e) {
             throw new ServletException(e);
         } catch (final TransformerException e) {
             throw new ServletException(e);
         }
     }
 
     /**
      * Gets the request info.
      *
      * @param doc
      *            the doc
      * @param request
      *            the request
      * @return the request info
      */
     private Element getRequestInfo(final Document doc, final HttpServletRequest request) {
         final Element node = doc.createElement("request");
 
         Element value = doc.createElement("AuthType");
         value.setTextContent(request.getAuthType());
         node.appendChild(value);
 
         final Principal p = request.getUserPrincipal();
         if (p != null) {
             final Element child = doc.createElement("principal");
             child.setAttribute("class", p.getClass().getName());
 
             value = doc.createElement("name");
             value.setTextContent(p.getName());
             child.appendChild(value);
 
             value = doc.createElement("string");
             value.setTextContent(p.toString());
             child.appendChild(value);
 
             node.appendChild(child);
         }
 
         final Enumeration<?> headers = request.getHeaderNames();
         if (headers.hasMoreElements()) {
             String name;
             final Element child = doc.createElement("headers");
             while (headers.hasMoreElements()) {
                 name = (String) headers.nextElement();
 
                 value = doc.createElement(name);
                 value.setTextContent(request.getHeader(name));
                 child.appendChild(value);
             }
             node.appendChild(child);
         }
         return node;
     }
 }