/**
    * This file Copyright (c) 2010-2011 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.rendering.engine;
  
  import info.magnolia.cms.beans.config.ServerConfiguration;
  import info.magnolia.context.MgnlContext;
  
  import java.io.PrintWriter;
  import java.io.Writer;
  
  import javax.inject.Inject;
  
  /**
   * Exception handler providing different output based on the configuration of the current instance. Full stacktrace gets
   * rendered on the author instance only, while ignoring the stacktraces in preview mode and on public instances.
   *
   * @version $Id$
   */
  public class ModeDependentRenderExceptionHandler implements RenderExceptionHandler {
  
      public static final String RENDER_ERROR_MESSAGE_BEGIN =
              "<!-- ERROR MESSAGE STARTS HERE --><script language=javascript>//\"></script><script language=javascript>//\'></script><script language=javascript>//\"></script><script language=javascript>//\'></script></title></xmp></script></noscript></style></object></head></pre></table></form></table></table></table></a></u></i></b><div align=left style='background-color:#FFFF00; color:#FF0000; display:block; border-top:double; padding:2pt; font-size:medium; font-family:Arial,sans-serif; font-style: normal; font-variant: normal; font-weight: normal; text-decoration: none; text-transform: none'><b style='font-size:medium'>FreeMarker template error!</b><pre><xmp>";
  
      public static final String RENDER_ERROR_MESSAGE_END = "</xmp></pre></div></html>";
  
      private ServerConfiguration serverConfiguration;
  
      @Inject
      public ModeDependentRenderExceptionHandler(ServerConfiguration config) {
          this.serverConfiguration = config;
      }
  
      @Override
      public void handleException(RenderException renderException, Writer out) {
          if ( serverConfiguration.isAdmin() && !MgnlContext.getAggregationState().isPreviewMode()) {
              inEditMode(renderException, out);
          } else {
              inPublicMode(renderException, out);
          }
      }
  
      private PrintWriter getPrintWriterFor(Writer out) {
          return (out instanceof PrintWriter) ? (PrintWriter) out : new PrintWriter(out);
      }
  
      protected void inPublicMode(RenderException renderException, Writer out) {
          final PrintWriter pw = getPrintWriterFor(out);
          renderException.printStackTrace(pw);
          pw.flush();
  
      }
  
      protected void inEditMode(RenderException renderException, Writer out) {
          final PrintWriter pw = getPrintWriterFor(out);
          pw.println(RENDER_ERROR_MESSAGE_BEGIN);
          renderException.printStackTrace(pw);
          pw.println(RENDER_ERROR_MESSAGE_END);
          pw.flush();
      }
  }