/**
 * <copyright> Copyright (c) 2006 by Know-Center, Graz, Austria </copyright>
 * 
 * This software is the confidential and proprietary information of Know-Center,
 * Graz, Austria. You shall not disclose such Confidential Information and shall
 * use it only in accordance with the terms of the license agreement you entered
 * into with Know-Center.
 * 
 * KNOW-CENTER MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT. KNOW-CENTER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
 * LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES.
 * 
 * $Id: Sign.java,v 1.7 2006/10/11 07:39:13 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.web.servlets;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.util.Iterator;
import java.util.List;

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.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.gv.egiz.pdfas.exceptions.ErrorCode;
import at.gv.egiz.pdfas.exceptions.ErrorCodeHelper;
import at.gv.egiz.pdfas.exceptions.external.ExternalErrorException;
import at.gv.egiz.pdfas.framework.input.PdfDataSource;
import at.gv.egiz.pdfas.utils.WebUtils;
import at.gv.egiz.pdfas.web.SignSessionInformation;
import at.gv.egiz.pdfas.web.helper.SignServletHelper;
import at.gv.egiz.pdfas.web.helper.TempDirHelper;
import at.knowcenter.wag.egov.egiz.PdfAS;
import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;
import at.knowcenter.wag.egov.egiz.exceptions.PlaceholderException;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
import at.knowcenter.wag.egov.egiz.pdf.TablePos;
import at.knowcenter.wag.egov.egiz.web.ExternAppInformation;
import at.knowcenter.wag.egov.egiz.web.FormFields;
import at.knowcenter.wag.egov.egiz.web.SessionAttributes;

/**
 * This method is the sign servlet for the pdf-as web application. It takes get
 * and post requests fill out jsp templates and give the user feedback about the
 * results of the sign process
 * 
 * @author wlackner
 * @author wprinz
 */
public class SignServlet extends HttpServlet
{

  /**
   * SVUID.
   */
  private static final long serialVersionUID = -4156938216903740438L;

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

  // The sign servlet is used for processing the upload only.
  // Authentication is deactivated. if required - make an own servlet.
  // /**
  // * @author modified by tknall
  // */
  // public void doGet(HttpServletRequest request, HttpServletResponse response)
  // throws ServletException, IOException
  // {
  // String authenticate = request.getHeader(AUTH);
  // if (authenticate != null)
  // {
  // logger_.info("authenticate:" + authenticate);
  // if (authenticate.indexOf(AUTH_BASIC) == 0)
  // {
  // authenticate = authenticate.substring(AUTH_BASIC.length() + 1);
  // logger_.info("authenticate:" + authenticate);
  // authenticate = new String(CodingHelper.decodeBase64(authenticate),
  // "UTF-8");
  // logger_.info("authenticate:" + authenticate);
  //
  // String[] auth_value = authenticate.split(":");
  // String user_name = auth_value[0];
  // String user_password = auth_value[1];
  // logger_.info("username:" + user_name);
  // // start modification tknall
  // // logger_.info("password:" + user_password);
  // logger_.info("password:XXXXXXXXXXXX");
  // // stop modification tknall
  //
  // HttpSession session = request.getSession();
  // session.setAttribute(SessionAttributes.ATTRIBUTE_USER_NAME, user_name);
  // session.setAttribute(SessionAttributes.ATTRIBUTE_USER_PASSWORD,
  // user_password);
  //
  // dispatch(request, response, "/jsp/signupload.jsp");
  // return;
  // }
  // // start modification tknall
  // } else {
  // String user_name = "";
  // String user_password = "";
  // logger_.info("authenticate:User has not been authenticated!");
  // logger_.info("username: UNKNOWN");
  // logger_.info("password: XXXXXXXXXXXX");
  // HttpSession session = request.getSession();
  // session.setAttribute("uname", user_name);
  // session.setAttribute("upass", user_password);
  // dispatch(request, response, "/jsp/signupload.jsp");
  // }

  // request.setAttribute("error", "Falsche Authentifikation");
  // request.setAttribute("cause", "Passwort oder Benutzername ist falsch");
  // dispatch(request, response, "/jsp/error.jsp");
  // // stop modification tknall
  // }

  /**
   * Processes the sign upload.
   * 
   * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
   *      javax.servlet.http.HttpServletResponse)
   */
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    UploadedData ud = null;
    ExternAppInformation exappinf = null;
    TablePos pos = null;
    
    // for performance measurement
    long startTime = 0; 
    long fileSize = 0;
    if (log.isInfoEnabled()) {
    	startTime = System.currentTimeMillis();    	
    }
    
    

    // check if pdf-as has been called by external webapp
    if (request.getParameter(FormFields.FIELD_PDF_URL) != null)
    {

      String preview = (String) request.getParameter(FormFields.FIELD_PREVIEW);
      String sig_type = (String) request.getParameter(FormFields.FIELD_SIGNATURE_TYPE);
      String sig_app = (String) request.getParameter(FormFields.FIELD_CONNECTOR);
      String sig_mode = (String) request.getParameter(FormFields.FIELD_MODE);
      String filename = (String) request.getParameter(FormFields.FIELD_FILENAME);
      String pdf_url = (String) request.getParameter(FormFields.FIELD_PDF_URL);
      String pdf_id = (String) request.getParameter(FormFields.FIELD_PDF_ID);
      String pdf_length = (String) request.getParameter(FormFields.FIELD_FILE_LENGTH);
      String invoke_url = (String) request.getParameter(FormFields.FIELD_INVOKE_APP_URL);
      String session_id = (String) request.getParameter(FormFields.FIELD_SESSION_ID);
      String sig_pos_y = (String) request.getParameter(FormFields.FIELD_SIGPOS_Y);
      String sig_pos_p = (String) request.getParameter(FormFields.FIELD_SIGPOS_P);

      // added by tknall
      if (sig_pos_y != null && sig_pos_p != null) {
         try
         {
           pos = new TablePos("y:" + sig_pos_y + ";p:" + sig_pos_p);
         }
         catch (PDFDocumentException e)
         {
           log.warn("Unable to create signature position object: " + e.getMessage(), e);
         }
      } else {
      	log.debug("No signature position provided.");
      }

      // fixed by tknall: if we already have parameters "&" must be used instead of "?"
      String paramSeparator = (pdf_url.indexOf("?") != -1) ? "&" : "?"; 
      String query = pdf_url + paramSeparator + FormFields.FIELD_PDF_ID + "=" + pdf_id;

      // wprinz: rem: this allocation is useless
      // byte[] extern_pdf = new byte[Integer.parseInt(pdf_length)];
      URL source_url = new URL(query);
      InputStream is = source_url.openStream();

      // extern_pdf = toByteArray(is);

      // set UploadedData object...
      UploadedData ud_extern = new UploadedData();

      ud_extern.file_name = filename;
      ud_extern.pdfDataSource = TempDirHelper.placePdfIntoTempDir(is, filename);
      // ud_extern.pdf = extern_pdf;
//      ud_extern.preview = preview.equalsIgnoreCase("true") ? true : false;
      ud_extern.preview = "true".equalsIgnoreCase(preview);
      ud_extern.sig_app = sig_app;
      ud_extern.sig_mode = sig_mode;
      ud_extern.sig_type = sig_type;

      ud = ud_extern;
      
      exappinf = new ExternAppInformation(invoke_url, pdf_id, session_id);
    }
    else
    {

      try
      {
        // tzefferer: modified
        // UploadedData ud = retrieveUploadedDataFromRequest(request);
        UploadedData ud_form = retrieveUploadedDataFromRequest(request);
        ud = ud_form;
        // end modify

      }
      catch (Exception e)
      {
        // Error retrieving data
        request.setAttribute("error", "Fehler beim Upload der Daten");
        request.setAttribute("cause", "Beim Upload der Daten ist ein Fehler aufgetreten.");
        dispatch(request, response, "/jsp/error.jsp");
        return;
      }
    }
    try
    {

      ud.pdfDataSource = PdfAS.applyStrictMode(ud.pdfDataSource);

      SignSessionInformation si = new SignSessionInformation(); // SessionTable.generateSessionInformationObject();
      si.connector = ud.sig_app;
      si.application = "sign";
      si.mode = ud.sig_mode;
      si.pdfDataSource = ud.pdfDataSource;
      si.type = ud.sig_type;
      si.filename = formatFileName(ud.file_name);
      si.download_inline = ud.download_inline;

      // added tzefferer:
      si.exappinf = exappinf;
      si.pos = pos;
      // end add

      request.getSession().setAttribute(SessionAttributes.ATTRIBUTE_SESSION_INFORMATION, si);

      // String user_name = (String)
      // request.getSession().getAttribute(SessionAttributes.ATTRIBUTE_USER_NAME);
      // String user_password = (String)
      // request.getSession().getAttribute(SessionAttributes.ATTRIBUTE_USER_PASSWORD);
      // si.user_name = user_name;
      // si.user_password = user_password;

      SignServletHelper.prepareSign(si);

      if (ud.preview)
      {
        String submit_url = response.encodeURL(request.getContextPath() + "/SignPreview");
//        String signature_data_url = response.encodeURL(WebUtils.addJSessionID(request.getContextPath() + "/RetrieveSignatureData", request));
        String signature_data_url = response.encodeURL(WebUtils.buildRetrieveSignatureDataURL(request, response));

        request.setAttribute("submit_url", submit_url);
        request.setAttribute("signature_data_url", signature_data_url);

        dispatch(request, response, "/jsp/signpreview.jsp");

        return;
      }
      
      SignServletHelper.finishSign(si, request, response, getServletContext());
      
      // for performance measurement
      if (log.isInfoEnabled()) {
      	long endTime = System.currentTimeMillis();
//      	String toReport = "SIGN;" + si.mode + ";" + si.filename + ";"+ fileSize + ";" + 
      	String toReport = "SIGN;" + si.mode + ";XXX;"+ fileSize + ";" + 
      	(endTime - startTime); 
      	
      	log.info(toReport);
      }
    }
    catch (PresentableException e)
    {
      log.error(e.getMessage(), e);
      prepareDispatchToErrorPage(e, request);
      dispatch(request, response, "/jsp/error.jsp");
    }
  }

  // tzefferer:added
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    doPost(request, response);
  }
  // end add

  protected UploadedData retrieveUploadedDataFromRequest(HttpServletRequest request) throws ServletException, UnsupportedEncodingException, FileUploadException, PDFDocumentException
  {
    DiskFileItemFactory fif = new DiskFileItemFactory();
    fif.setRepository(SettingsReader.getTemporaryDirectory());
    ServletFileUpload sfu = new ServletFileUpload(fif);

    List items = sfu.parseRequest(request);

    FileItem preview_fi = null;
    FileItem sig_type_fi = null;
    FileItem sig_app_fi = null;
    FileItem mode_fi = null;
    FileItem file_upload_fi = null;
    FileItem download_fi = null;

    Iterator it = items.iterator();
    while (it.hasNext())
    {
      FileItem item = (FileItem) it.next();
      log.debug("item = " + item.getFieldName()); //$NON-NLS-1$

      if (log.isDebugEnabled())
      {
        if (item.isFormField())
        {
          String item_string = item.getString("UTF-8"); //$NON-NLS-1$
          log.debug("  form field string = " + item_string); //$NON-NLS-1$
        }
        else
        {
          log.debug("  filename = " + item.getName()); //$NON-NLS-1$
          log.debug("  filesize = " + item.getSize()); //$NON-NLS-1$
        }
      }

      if (item.getFieldName().equals(FormFields.FIELD_PREVIEW))
      {
        preview_fi = item;
        continue;
      }

      if (item.getFieldName().equals(FormFields.FIELD_SIGNATURE_TYPE))
      {
        sig_type_fi = item;
        continue;
      }

      if (item.getFieldName().equals(FormFields.FIELD_CONNECTOR))
      {
        sig_app_fi = item;
        continue;
      }

      if (item.getFieldName().equals(FormFields.FIELD_MODE))
      {
        mode_fi = item;
        continue;
      }

      if (item.getFieldName().equals(FormFields.FIELD_UPLOAD))
      {
        file_upload_fi = item;
        continue;
      }

      if (item.getFieldName().equals(FormFields.FIELD_DOWNLOAD))
      {
        download_fi = item;
        continue;
      }

      throw new ServletException("unrecognized POST data."); //$NON-NLS-1$

    }

    if (preview_fi == null || sig_type_fi == null || sig_app_fi == null || file_upload_fi == null || download_fi == null)
    {
      throw new ServletException("Insufficient data provided in request"); //$NON-NLS-1$
    }

    String mode = mode_fi.getString("UTF-8"); //$NON-NLS-1$
    if (!mode.equals(FormFields.VALUE_MODE_BINARY) && !mode.equals(FormFields.VALUE_MODE_TEXTUAL) && !mode.equals(FormFields.VALUE_MODE_DETACHED))
    {
      throw new ServletException("The mode '" + mode + "' is unrecognized."); //$NON-NLS-1$ //$NON-NLS-2$
    }

    String preview_str = preview_fi.getString("UTF-8"); //$NON-NLS-1$
    boolean preview = false;
    if (preview_str.equals("true")) //$NON-NLS-1$
    {
      preview = true;
    }

    boolean download_inline = true;
    if (download_fi.getString("UTF-8").equals(FormFields.VALUE_DOWNLOAD_ATTACHMENT)) //$NON-NLS-1$
    {
      download_inline = false;
    }

    String sig_type = sig_type_fi.getString("UTF-8"); //$NON-NLS-1$
    String sig_app = sig_app_fi.getString("UTF-8"); //$NON-NLS-1$

    String doc_file_name = TempDirHelper.extractFileNameSuffix(file_upload_fi.getName());
    log.debug("file content type =" + file_upload_fi.getContentType()); //$NON-NLS-1$

    String extension = VerifyServlet.extractExtension(doc_file_name);
    if (extension != null && !extension.equals("pdf")) //$NON-NLS-1$
    {
      throw new PDFDocumentException(201, "The provided file '" + doc_file_name + "' doesn't have the PDF extension (.pdf)."); //$NON-NLS-1$//$NON-NLS-2$
    }

    if (file_upload_fi.getSize() <= 0)
    {
      throw new PDFDocumentException(250, "The document is empty."); //$NON-NLS-1$
    }

    PdfDataSource pdfDataSource = null;
    try
    {
      pdfDataSource = TempDirHelper.placePdfIntoTempDir(file_upload_fi.getInputStream(), doc_file_name);
    }
    catch (IOException e)
    {
      throw new PDFDocumentException(201, "Couldn't store the file in the temp dir.", e);
    }
    // byte[] pdf = file_upload_fi.get();

    UploadedData ud = new UploadedData();

    ud.preview = preview;
    ud.download_inline = download_inline;
    ud.sig_type = sig_type;
    ud.sig_app = sig_app;
    ud.sig_mode = mode;
    ud.file_name = doc_file_name;
    ud.pdfDataSource = pdfDataSource;

    return ud;
  }





  public static void prepareDispatchToErrorPage(PresentableException pe, HttpServletRequest request)
  {
    request.setAttribute("PresentableException", pe);
//    if (pe instanceof ErrorCodeException)
//    {
      request.setAttribute("error", "Fehler " + pe.getErrorCode());

      String cause = ErrorCodeHelper.getMessageForErrorCode(pe.getErrorCode());
      
      if (pe instanceof ExternalErrorException)
      {
        ExternalErrorException eee = (ExternalErrorException) pe;
        cause = eee.getExternalErrorCode() + ": " + eee.getExternalErrorMessage();
      }
      request.setAttribute("cause", cause);

      if (pe.getErrorCode() == ErrorCode.PLACEHOLDER_EXCEPTION)
      {
        PlaceholderException phe = null;
        if (pe instanceof PlaceholderException)
        {
          phe = (PlaceholderException) pe;
        }
        else
        {
          phe = (PlaceholderException) pe.getCause();
        }

        request.setAttribute("cause", "Der Platzhalter des Feldes " + phe.getField() + " ist um " + phe.getMissing() + " Bytes zu kurz. " + cause);
      }
//    }
//    else
//    {
//      request.setAttribute("error", "PresentableException");
//      request.setAttribute("cause", pe.toString());
//    }
  }

  public void dispatchToPreview(String document_text, String connector, String mode, String signature_type, String submit_url, HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException
  {
    request.setAttribute("document_text", document_text);
    request.setAttribute("connector", connector);
    request.setAttribute("mode", mode);
    request.setAttribute("signature_type", signature_type);
    request.setAttribute("submit_url", submit_url);

    dispatch(request, response, "/jsp/signpreview.jsp");
  }

  /**
   * Formats the file name so that it is suitable for content disposition.
   * 
   * @param file_name
   *          The file name.
   * @return Returns the formatted file name.
   */
  public static String formatFileName(String file_name)
  {
    File file = new File(file_name);
    String file_name_only = file.getName();
    // the file_name contains \\ ==> remove them so Internet Explorer works
    // correctly.
    return file_name_only;
  }





  // tzefferer: added
  public static byte[] toByteArray(InputStream inputStream) throws IOException
  {

    if (inputStream == null)
    {
      return null;
    }

    ByteArrayOutputStream out = new ByteArrayOutputStream(8192);
    int n;
    byte[] buffer = new byte[2048];
    BufferedInputStream bufIn = new BufferedInputStream(inputStream);
    try
    {
      while ((n = bufIn.read(buffer)) != -1)
      {
        out.write(buffer, 0, n);
      }
    }
    finally
    {
      if (bufIn != null)
      {
        bufIn.close();
      }
    }
    return out.toByteArray();
  }

  // end add

  protected static class UploadedData
  {
    protected boolean preview = false;

    protected boolean download_inline = false;

    protected String sig_type = null;

    protected String sig_app = null;

    protected String sig_mode = null;

    protected String file_name = null;

    protected PdfDataSource pdfDataSource = null;
    // protected byte[] pdf = null;
  }
}