/*
 * Created on 19.11.2003
 *
 * (c) Stabsstelle IKT-Strategie des Bundes
 */
package at.gv.egovernment.moa.spss.slinterface.servlets;

import java.io.IOException;
import java.rmi.RemoteException;
import java.util.Properties;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.rpc.ServiceException;

import org.apache.log4j.Logger;
import org.apache.xerces.parsers.DOMParser;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import at.gv.egovernment.moa.spss.slinterface.Constants;
import at.gv.egovernment.moa.spss.slinterface.moainvoker.MOAInvoker;

/**
 * @author Gregor Karlinger (mailto:gregor.karlinger@cio.gv.at) 
 */
public class MOAServlet extends HttpServlet
{
  private static Logger logger_ = Logger.getLogger(Constants.LH_SERVLETS_);

  /**
   * Default constructor.
   */
  public MOAServlet()
  {
    super();
  }
  
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException
  {
    // Get moa request form http request
    Document moaXmlRequest = null;
    DOMParser xmlParser = (DOMParser) this.getServletContext().getAttribute(Constants.WSCP_XMLPARSER_);
    try
    {
      InputSource requestIS = new InputSource(request.getInputStream());
      xmlParser.parse(requestIS);
      moaXmlRequest = xmlParser.getDocument();
    }
    catch (IOException ioe)
    {
      String message = "Getting MOA XML request from http request input failed.";
      logger_.error(message, ioe);
      throw new ServletException(message, ioe);
    }
    catch (SAXException se)
    {
      String message = "Parsing MOA XML request got from http request failed.";
      logger_.error(message, se);
      throw new ServletException(message, se);
    }
    
    // Send request to MOA SP
    Properties initProps = (Properties) this.getServletContext().getAttribute(Constants.WSCP_INIT_PROPS_);
    String endPoint = initProps.getProperty(Constants.IP_SP_ENDPOINT_);
    if (endPoint == null)
    {
      String message = "No endpoint configured for MOA SP service.";
      logger_.error(message);
      throw new ServletException(message);
    }
    Document moaXMLResponseDoc = null;
    try
    {
      moaXMLResponseDoc = MOAInvoker.invokeSP(moaXmlRequest, endPoint);
    }
    catch (Exception e)
    {
      String message;
      if (e instanceof RemoteException)
      {
        message = "MOA SP service indicated an error at request execution.";
      }
      else if (e instanceof ServiceException)
      {
        message = "MOA SP client indicated an error at request execution.";
      }
      else
      {
        message = "Could not create DOM Document from MOA SP service response.";
      }
      logger_.error(message, e);
      throw new ServletException(message, e);
    }      
    
    // Write moa response to http response
    try
    {
      MOAInvoker.serializeDocument(moaXMLResponseDoc, response.getOutputStream());
    }
    catch (IOException e)
    {
      String message = "Writing MOA SP XML response to http response failed.";
      logger_.error(message, e);
      throw new ServletException(message, e);
    }
  }
}