/*
 * Created on 25.11.2003
 *
 * (c) Stabsstelle IKT-Strategie des Bundes
 */
package at.gv.egovernment.moa.ss.erechtclient.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Properties;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

import at.gv.egovernment.moa.ss.erechtclient.ERechtClientException;
import at.gv.egovernment.moa.ss.erechtclient.init.Constants;

/**
 * @author Gregor Karlinger (mailto:gregor.karlinger@cio.gv.at) 
 */
public class Utils
{
  public static byte[] readFromInputStream(InputStream inputStream) throws IOException
  {
    byte[] currentBytes = new byte[500];
    int bytesRead;
    ByteArrayOutputStream result = new ByteArrayOutputStream();
    do
    {
      bytesRead = inputStream.read(currentBytes);
      if (bytesRead > 0)
      {
        result.write(currentBytes, 0, bytesRead);
      }
    }
    while (bytesRead != -1);
    return result.toByteArray();
  }
  
  /* ---------------------------------------------------------------------------------------------------- */

  public static void transferStreams(InputStream in, OutputStream out) throws IOException
  {
    byte[] currentBytes = new byte[500];
    int bytesRead;
    do
    {
      bytesRead = in.read(currentBytes);
      if (bytesRead > 0)
      {
        out.write(currentBytes, 0, bytesRead);
      }
    }
    while (bytesRead != -1);
  }

  /* ---------------------------------------------------------------------------------------------------- */

  public static void returnErrorPage(HttpServletRequest request, HttpServletResponse response, Throwable t)
    throws ServletException
  {
    Logger logger = Logger.getLogger(Constants.LH_SERVLETS_);

    // Store Throwable in request context
    request.setAttribute(Constants.RCP_ERROR_THROWABLE_, t);

    RequestDispatcher dispatcher = request.getRequestDispatcher(Constants.JSPPN_ERROR_);
    try 
    {
      dispatcher.include(request, response);
    } 
    catch (ServletException e) 
    {
      logger.error("Returning error JSP page failed.", e);
      throw e;
    } 
    catch (IOException e) 
    {
      String message = "Returning error JSP page failed.";
      logger.error(message, e);
      throw new ServletException(message, e);
    }
  }
  
  /* ---------------------------------------------------------------------------------------------------- */

  public static String readInitProperty(Properties initProps, String name, Logger logger) 
    throws ERechtClientException
  {
    String value = initProps.getProperty(name);
    if (value == null)
    {
      String message = "Could not read property \"" + name + "\" from configuration properties.";
      logger.error(message);
      throw new ERechtClientException(message);
    }
    return value;
  }
}