/**
 * 
 */
package at.knowcenter.wag.egov.egiz.web.servlets;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
import at.knowcenter.wag.egov.egiz.framework.Signator;
import at.knowcenter.wag.egov.egiz.framework.SignatorFactory;
import at.knowcenter.wag.egov.egiz.pdf.SignatureHolder;
import at.knowcenter.wag.egov.egiz.sig.SignatureResponse;
import at.knowcenter.wag.egov.egiz.sig.connectors.ConnectorChooser;
import at.knowcenter.wag.egov.egiz.sig.connectors.LocalConnector;
import at.knowcenter.wag.egov.egiz.sig.connectors.bku.BKUPostConnection;
import at.knowcenter.wag.egov.egiz.sig.connectors.bku.EnvelopedBase64BKUConnector;
import at.knowcenter.wag.egov.egiz.sig.connectors.bku.LocRefDetachedBKUConnector;
import at.knowcenter.wag.egov.egiz.web.FormFields;
import at.knowcenter.wag.egov.egiz.web.LocalRequest;
import at.knowcenter.wag.egov.egiz.web.SessionAttributes;
import at.knowcenter.wag.egov.egiz.web.SessionInformation;

/**
 * @author wprinz
 * 
 */
public class DataURLServlet extends HttpServlet
{

  /**
   * SVUID.
   */
  private static final long serialVersionUID = -5846618335843762752L;

  /**
   * The log.
   */
  private static Log log = LogFactory.getLog(DataURLServlet.class);

  protected void dispatch(HttpServletRequest request,
      HttpServletResponse response, String resource) throws ServletException, IOException
  {
    dispatch(request, response, resource, getServletContext());
  }

  protected static void dispatch(HttpServletRequest request,
      HttpServletResponse response, String resource, ServletContext context) throws ServletException, IOException
  {
    response.setContentType("text/html");
    response.setCharacterEncoding("UTF-8");

    RequestDispatcher disp = context.getRequestDispatcher(resource);
    disp.forward(request, response);
  }

  protected void dispatchToResults(List results, HttpServletRequest request,
      HttpServletResponse response) throws ServletException, IOException
  {
    request.setAttribute("results", results);
    dispatch(request, response, "/jsp/results.jsp");
  }

  /**
   * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
   *      javax.servlet.http.HttpServletResponse)
   */
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    log.debug("Data URL is accessed."); //$NON-NLS-1$

    HttpSession session = request.getSession(false);
    if (session == null)
    {
      String msg = "There is no session associated with this request."; //$NON-NLS-1$
      log.error(msg);
      throw new ServletException(msg);
    }

    SessionInformation si = (SessionInformation) session.getAttribute(SessionAttributes.ATTRIBUTE_SESSION_INFORMATION);
    if (si == null)
    {
      String msg = "The session is not found or no longer valid."; //$NON-NLS-1$
      log.error(msg);
      throw new ServletException(msg);
    }

    try
    {
      log.debug("Request character encoding = " + request.getCharacterEncoding()); //$NON-NLS-1$
      if (request.getCharacterEncoding() == null || request.getCharacterEncoding().equals("UTF-8")) //$NON-NLS-1$
      {
        log.error("The BKU didn't set a character encoding for the request."); //$NON-NLS-1$

        log.warn("Manually setting character encoding to UTF-8"); //$NON-NLS-1$
        request.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
      }

      String xml_response = request.getParameter("XMLResponse"); //$NON-NLS-1$
      log.debug("xml_response = " + xml_response); //$NON-NLS-1$

      if (isNullResponse(xml_response))
      {
        log.debug("Received a NullOperationResponse -> answering with the first request."); //$NON-NLS-1$

        assert si.current_operation == 0;
      }
      else
      {
        log.debug("Recieved a normal response -> storing the response."); //$NON-NLS-1$

        Properties response_properties = new Properties();
        response_properties.setProperty(BKUPostConnection.RESPONSE_STRING_KEY, xml_response);
        si.response_properties[si.current_operation] = response_properties;

        si.current_operation++;
      }

      if (si.current_operation < si.requests.length)
      {
        log.debug("There are still requests to be performed -> answering with request #" + si.current_operation); //$NON-NLS-1$

        LocalRequest local_request = si.requests[si.current_operation];

        String request_string = local_request.getRequestString();

        response.setContentType("text/xml");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().println(request_string);
      }
      else
      {
        log.debug("All requests have been processed -> processing the responses."); //$NON-NLS-1$

        if (si.application.equals("sign"))
        {
          // Sign
          
          if (si.sign_result == null)
          {
            LocalConnector c = ConnectorChooser.chooseLocalConnectorForSign(si.connector, si.type, "loc ref content not needed here"); //$NON-NLS-1$

            si.iui.signed_signature_object = c.analyzeSignResponse(si.response_properties[0]);

            PdfASID algorithm = FormFields.translateSignatureModeToPdfASID(si.mode);
            Signator signator = SignatorFactory.createSignator(algorithm);

            si.sign_result = signator.finishSign(si.iui);
          }

          SignServlet.returnSignResponse(si, response);
        }
        else
        {
          // Verify
          
          List results = new ArrayList();

          for (int i = 0; i < si.response_properties.length; i++)
          {
            SignatureHolder sh = (SignatureHolder) si.signature_holders.get(i);
            
            PdfASID sig_kz = sh.getSignatureObject().getKZ();
            String sig_id = sh.getSignatureObject().getSignationIds();
            
            LocalConnector c = ConnectorChooser.chooseLocalConnectorForVerify(si.connector, sig_kz, sig_id, si.type, "loc ref content not needed here"); //$NON-NLS-1$

            SignatureResponse sig_resp = c.analyzeVerifyResponse(si.response_properties[i]);
            results.add(sig_resp);
          }

          dispatchToResults(results, request, response);
        }
      }
    }
    catch (PresentableException e)
    {
      log.error(e);
      SignServlet.prepareDispatchToErrorPage(e, request);
      dispatch(request, response, "/jsp/error.jsp");
    }

    log.debug("DataURL access finished."); //$NON-NLS-1$
  }

  protected boolean isNullResponse(String xml_response)
  {
    return xml_response.indexOf("NullOperationResponse") >= 0;
  }
}