content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.ui.error;
  
  import org.opencms.file.CmsObject;
  import org.opencms.flex.CmsFlexController;
  import org.opencms.jsp.util.Messages;
  import org.opencms.main.CmsLog;
  import org.opencms.main.CmsMultiException;
  import org.opencms.main.I_CmsThrowable;
  import org.opencms.main.OpenCms;
  import org.opencms.ui.A_CmsUI;
  import org.opencms.ui.CmsVaadinUtils;
  import org.opencms.ui.apps.CmsLegacyApp;
  import org.opencms.ui.components.CmsErrorDialog;
  import org.opencms.ui.shared.CmsVaadinConstants;
  import org.opencms.util.CmsFileUtil;
  import org.opencms.util.CmsMacroResolver;
  import org.opencms.util.CmsStringUtil;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.apache.commons.logging.Log;
  
  import com.vaadin.annotations.Theme;
  import com.vaadin.server.VaadinRequest;
  import com.vaadin.server.WrappedSession;
  import com.vaadin.shared.Version;
  import com.vaadin.ui.JavaScript;
  
  /**
   * Displays the error page.<p>
   */
  @Theme("opencms")
  public class CmsErrorUI extends A_CmsUI {
  
      /** The serial version id. */
      private static final long serialVersionUID = -7274300240145879438L;
  
      /** Logger instance for this class. */
      private static final Log LOG = CmsLog.getLog(CmsErrorUI.class);
  
      /** The throwable session attribute name. */
      private static final String THROWABLE = "THROWABLE";
  
      /** The path session attribute name. */
      private static final String PATH = "PATH";
  
      /** The error page path fragment. */
      public static final String ERROR_PAGE_PATH_FRAQUMENT = "errorpage/";
  
      /** The path to the requested page. */
      @SuppressWarnings("unused")
      private String m_requestedPage;
  
      /** The displayed exception. */
      private Throwable m_throwable;
  
      /**
       * Returns the error bootstrap page HTML.<p>
       *
       * @param cms the cms context
       * @param throwable the throwable
       * @param request the current request
       *
       * @return the error bootstrap page HTML
       */
      public static String getBootstrapPage(CmsObject cms, Throwable throwable, HttpServletRequest request) {
  
          try {
              setErrorAttributes(cms, throwable, request);
  
              byte[] pageBytes = CmsFileUtil.readFully(
                  Thread.currentThread().getContextClassLoader().getResourceAsStream(
                      "org/opencms/ui/error/error-page.html"));
              String page = new String(pageBytes, "UTF-8");
              CmsMacroResolver resolver = new CmsMacroResolver();
              String context = OpenCms.getSystemInfo().getContextPath();
              String vaadinDir = CmsStringUtil.joinPaths(context, "VAADIN/");
              String vaadinVersion = Version.getFullVersion();
              String vaadinServlet = CmsStringUtil.joinPaths(context, "workplace/", ERROR_PAGE_PATH_FRAQUMENT);
              String vaadinBootstrap = CmsStringUtil.joinPaths(context, "VAADIN/vaadinBootstrap.js");
  
              resolver.addMacro("loadingHtml", CmsVaadinConstants.LOADING_INDICATOR_HTML);
              resolver.addMacro("vaadinDir", vaadinDir);
              resolver.addMacro("vaadinVersion", vaadinVersion);
              resolver.addMacro("vaadinServlet", vaadinServlet);
              resolver.addMacro("vaadinBootstrap", vaadinBootstrap);
              resolver.addMacro("title", "Error page");
  
              page = resolver.resolveMacros(page);
              return page;
          } catch (Exception e) {
              LOG.error("Failed to display error page.", e);
              return "<!--Error-->";
          }
      }
  
      /**
       * Sets the error attributes to the current session.<p>
       *
       * @param cms the cms context
       * @param throwable the throwable
       * @param request the current request
       */
      private static void setErrorAttributes(CmsObject cms, Throwable throwable, HttpServletRequest request) {
  
          String errorUri = CmsFlexController.getThrowableResourceUri(request);
          if (errorUri == null) {
              errorUri = cms.getRequestContext().getUri();
          }
  
          // try to get the exception root cause
          Throwable cause = CmsFlexController.getThrowable(request);
          if (cause == null) {
              cause = throwable;
          }
  
          request.getSession().setAttribute(THROWABLE, cause);
          request.getSession().setAttribute(PATH, errorUri);
      }
  
      /**
       * @see com.vaadin.ui.UI#init(com.vaadin.server.VaadinRequest)
       */
      @Override
      protected void init(VaadinRequest request) {
  
          readErrorAttributes();
          CmsErrorDialog.showErrorDialog(getErrorMessage(m_throwable), m_throwable, new Runnable() {
  
              public void run() {
  
                  JavaScript.eval(
                      "if (window.parent && window.parent."
                          + CmsLegacyApp.VAR_IS_LEGACY_APP
                          + ") window.parent.location.reload();");
              }
          });
      }
  
      /**
       * Returns the error message to be displayed.<p>
       *
       * @param throwable the throwable
       *
       * @return the error message to be displayed
       */
      private String getErrorMessage(Throwable throwable) {
  
          StringBuffer result = new StringBuffer(512);
  
          result.append(
              CmsVaadinUtils.getMessageText(org.opencms.ui.components.Messages.GUI_ERROR_DIALOG_MESSAGE_0)).append(
                  "<br />");
  
          // if a localized message is already set as a parameter, append it.
          result.append(getMessage(throwable));
  
          return result.toString();
      }
  
      /**
       * Returns the localized Message, if the argument is a CmsException, or
       * the message otherwise.<p>
       *
       * @param t the Throwable to get the message from
       *
       * @return returns the localized Message, if the argument is a CmsException, or
       * the message otherwise
       */
      private String getMessage(Throwable t) {
  
          if ((t instanceof I_CmsThrowable) && (((I_CmsThrowable)t).getMessageContainer() != null)) {
              StringBuffer result = new StringBuffer(256);
              if (t instanceof CmsMultiException) {
                  CmsMultiException exc = (CmsMultiException)t;
                  String message = exc.getMessage(getLocale());
                  if (CmsStringUtil.isNotEmpty(message)) {
                      result.append(message);
                      result.append("<br />");
                  }
  
              }
  
              I_CmsThrowable cmsThrowable = (I_CmsThrowable)t;
              result.append(cmsThrowable.getLocalizedMessage(getLocale()));
              return result.toString();
          } else {
              String message = t.getMessage();
              if (CmsStringUtil.isEmptyOrWhitespaceOnly(message)) {
                  // no error message found (e.g. for NPE), provide default message text
                  message = CmsVaadinUtils.getMessageText(Messages.GUI_ERROR_UNKNOWN_0);
              }
              return message;
          }
      }
  
      /**
       * Reads the error attributes from current session.<p>
       */
      private void readErrorAttributes() {
  
          WrappedSession session = getSession().getSession();
          m_requestedPage = (String)session.getAttribute(PATH);
          m_throwable = (Throwable)session.getAttribute(THROWABLE);
  
          // remove the attributes after read to keep the session clean
          session.removeAttribute(THROWABLE);
          session.removeAttribute(PATH);
      }
  }
  