/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */
package at.gv.egiz.pdfas.web.servlets;

import java.io.IOException;

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

import at.gv.egiz.pdfas.api.commons.SignatureInformation;
import at.gv.egiz.pdfas.api.io.DataSource;
import at.gv.egiz.pdfas.api.verify.VerifyResult;
import at.gv.egiz.pdfas.exceptions.web.SessionExpiredException;
import at.gv.egiz.pdfas.web.helper.SessionHelper;
import at.gv.egiz.pdfas.web.session.SignSessionInformation;
import at.gv.egiz.pdfas.web.session.VerifySessionInformation;

/**
 * Retrieves the Signature Data from the session and returns it.
 * 
 * @author wprinz
 */
public class RetrieveSignatureDataServlet extends HttpServlet
{

  /**
   * SVUID.
   */
  private static final long serialVersionUID = -5387006236836240538L;

  /**
   * The log.
   */
  private static Log log = LogFactory.getLog(RetrieveSignatureDataServlet.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);
  }

/**
   * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
   *      javax.servlet.http.HttpServletResponse)
   */
  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    if (log.isDebugEnabled()) {
       log.debug("Request for receiving signature data."); //$NON-NLS-1$
       log.debug("Requested session id is = " + request.getRequestedSessionId());
    }

    try
    {
    Object sessionObject = SessionHelper.getSession(request);

    if (sessionObject instanceof SignSessionInformation)
    {
      SignSessionInformation si = (SignSessionInformation) sessionObject;
      processSign(request, response, si);
    }
    else
    {
      VerifySessionInformation si = (VerifySessionInformation) sessionObject;
      processVerify(request, response, si);
    }
    }
    catch (SessionExpiredException e)
    {
      log.error(e.getMessage(), e);
      SignServlet.prepareDispatchToErrorPage(e, request);
      dispatch(request, response, "/jsp/error.jsp");
    }
  }

  protected void processSign(HttpServletRequest request, HttpServletResponse response, SignSessionInformation si) throws ServletException, IOException
  {
    writeSignatureData(si.sdi.getSignatureData(), response);
  }

  protected void processVerify(HttpServletRequest request, HttpServletResponse response, VerifySessionInformation si) throws ServletException, IOException
  {

    DataSource data = null;
    if (si.currentLocalOperation != null)
    {
      data = ((SignatureInformation) si.currentLocalOperation.signaturesToBeverified.get(si.currentLocalOperation.current_operation)).getSignedData();
    }
    else
    {
      data = ((VerifyResult)si.verifyResults.getResults().get(0)).getSignedData();
    }

    writeSignatureData(data, response);
  }

  protected void writeSignatureData(DataSource ds, HttpServletResponse response) throws IOException
  {
    log.trace("Writing " + ds.getMimeType() + " data:"); //$NON-NLS-1$ //$NON-NLS-2$

    response.setContentType(ds.getMimeType());
    response.setCharacterEncoding(ds.getCharacterEncoding());
    // [tknall] content length must be set, otherwise ITS BKU for Mac rejects the request. 
    response.setContentLength(ds.getLength());
    IOUtils.copy(ds.createInputStream(), response.getOutputStream());

    log.trace("Writing SignatureData finished."); //$NON-NLS-1$
  }
}