/*
    * $Id: ResourceDetailsServlet.java 1537 2011-07-27 15:34:04Z hoheisel $
    *
    * Copyright (c) 2007
    * Fraunhofer Institute for Computer Architecture and Software Technology
    * See http://www.first.fraunhofer.de for more details.
    */
   
   package net.kwfgrid.gwes.servlet;
  
  import net.kwfgrid.gwes.client.RemoteGWES;
  import net.kwfgrid.gwes.exception.GWESException;
  import org.antlr.stringtemplate.StringTemplate;
  import org.apache.log4j.Logger;
  import org.jdom.transform.XSLTransformer;
  import org.jdom.Document;
  import org.jdom.output.XMLOutputter;
  import org.jdom.output.Format;
  import org.jdom.input.SAXBuilder;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.*;
  
  /**
   * Servlet that shows details of a specific workflow.
   * Security should be implemented by means of the Servlet container (e.g. using tomcat-users.xml)
   *
   * @author Andreas Hoheisel
   *         (<a href="http://www.andreas-hoheisel.de">www.andreas-hoheisel.de</a>)
   * @version $Id: ResourceDetailsServlet.java 1537 2011-07-27 15:34:04Z hoheisel $
   */
  public class ResourceDetailsServlet extends HttpServlet {
  
      private static GWESProperties pr;
      final static Logger logger = Logger.getLogger(ResourceDetailsServlet.class);
  
      protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          ServletLogger.log(request);
  
          response.setContentType("text/html");
          PrintWriter out = response.getWriter();
          String error = null;
          String success = null;
          String info = null;
  
          Object obj = request.getAttribute("error");
          if (obj instanceof String) error = (String) obj;
  
          obj = request.getAttribute("success");
          if (obj instanceof String) success = (String) obj;
  
          obj = request.getAttribute("info");
          if (obj instanceof String) info = (String) obj;
  
          //read gwes.properties
          if (pr == null) pr = GWESProperties.getInstance("/gwes.properties");
  
          // get user
          String userID = request.getRemoteUser();
          if (userID == null) userID = "nn";
  
          // get resource Uri
          String resourceUri = request.getParameter("resourceuri");
          if (resourceUri == null) {
              obj = request.getSession().getAttribute("resourceuri");
              if (obj instanceof String) resourceUri = (String) obj;
          } else {
              logger.debug("session resourceuri = " + resourceUri);
              request.getSession().setAttribute("resourceuri", resourceUri);
          }
  
          String resourceHtml = null;
          try {
              resourceHtml = getDGRDLHTML(resourceUri, request.getUserPrincipal().getName());
          } catch (Throwable e) {
              logger.error("exception: " + e, e);
              error = ((error == null) ? "" : error) + "Could not get resource information: " + e.getMessage();
              info = "<p>Please select an available resource in the <a href=\"" + pr.gwesBaseUrlExternal + "/servlet/ResourceListServlet\">Resource List</a> or in the <a href=\"" + pr.gwesBaseUrlExternal + "/servlet/WorkflowActivityListServlet\">Activity List</a> first!</p>";
              resourceUri = null;
          }
  
          if (error == null && (resourceUri == null || resourceUri.length() == 0)) {
              info = "<p>Please select an available resource in the <a href=\"" + pr.gwesBaseUrlExternal + "/servlet/ResourceListServlet\">Resource List</a> or in the <a href=\"" + pr.gwesBaseUrlExternal + "/servlet/WorkflowActivityListServlet\">Activity List</a> first!</p>";
          }
  
          try {
              StringTemplate t = Template.getStringTemplateGroup("html_gwes-servlets").getInstanceOf("resourceDetails");
              if (resourceHtml != null) t.setAttribute("resourcehtml", resourceHtml);
              if (success != null) t.setAttribute("success", success);
              if (error != null) t.setAttribute("error", error);
              if (info != null) t.setAttribute("info", info);
              t.setAttribute("menu", new Menu(pr.gwesBaseUrlExternal, "Resource Details"));
              out.print(t.toString());
          } catch (Exception e) {
              out.println("<hr><b>ERROR connecting to GWES: " + e + "</b>");
              out.println("<pre>");
             e.printStackTrace(out);
             out.println("</pre>");
             out.println("<hr>");
         }
     }
 
     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         doGet(request, response);
     }
 
     private String getDGRDLHTML(String resourceUri, String userID) throws Exception, GWESException {
         if (resourceUri == null) return null;
 
         // get resource description from GWES
         String xmlStr = RemoteGWES.getInstance().getResourceDescription(resourceUri, userID);
 
         // convert to JDOM
         SAXBuilder builder = new SAXBuilder(false);
         Document xmlJdom = builder.build(new StringReader(xmlStr));
 
         // transform using XSLT
         System.setProperty( "javax.xml.transform.TransformerFactory", "org.apache.xalan.processor.TransformerFactoryImpl");
         XSLTransformer transformer = new XSLTransformer(getClass().getResourceAsStream("/templates/dgrdl.xsl"));
         Document htmlJdom = transformer.transform(xmlJdom);
 
         // convert to String
         Writer writer = new StringWriter();
         XMLOutputter outp = new XMLOutputter(Format.getCompactFormat());
         outp.output(htmlJdom, writer);
         return writer.toString();
     }
 
 }