package org.apache.velocity.tools.struts;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.util.Locale;
  import java.util.Iterator;
  
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpSession;
  
  import org.apache.struts.Globals;
  import org.apache.struts.action.ActionForm;
  import org.apache.struts.action.ActionMessage;
  import org.apache.struts.action.ActionMessages;
  import org.apache.struts.config.ModuleConfig;
  import org.apache.struts.config.ForwardConfig;
  import org.apache.struts.config.ActionConfig;
  import org.apache.struts.util.MessageResources;
  import org.apache.struts.util.RequestUtils;
  import org.apache.struts.taglib.TagUtils;
  import org.apache.struts.util.ModuleUtils;
  
  /**
   * <p>A utility class to expose the Struts shared
   * resources. All methods are static.</p>
   *
   * <p>This class is provided for use by Velocity view tools
   * that need access to Struts resources. By having all Struts-
   * specific code in this utility class, maintenance is simplified
   * and reuse fostered.</p>
   *
   * <p>It is the aim, that sooner or later the functionality in
   * this class is integrated into Struts itself.  See
   * <a href="http://nagoya.apache.org/bugzilla/show_bug.cgi?id=16814">Bug #16814</a>
   * for more on that.</p>
   *
   * @author <a href="mailto:marinoj@centrum.is">Marino A. Jonsson</a>
   * @author Nathan Bubna
   * @author <a href="mailto:sidler@teamup.com">Gabe Sidler</a>
   * based on code by <a href="mailto:ted@husted.org">Ted Husted</a>
   *
   * @version $Id: StrutsUtils.java 670093 2008-06-20 23:10:11Z nbubna $
   */
  public class StrutsUtils
  {
      public static final StrutsUtils INSTANCE = new StrutsUtils();
  
      private StrutsUtils() {}
  
      public StrutsUtils getInstance()
      {
          return INSTANCE;
      }
  
      /****************** Struts ServletContext Resources ****************/
  
      /**
       * Returns the message resources for this application or <code>null</code>
       * if not found.
       *
       * @param app the servlet context
       * @since VelocityTools 1.1
       */
      public static MessageResources getMessageResources(HttpServletRequest request,
                                                         ServletContext app)
      {
          return getMessageResources(request, app, null);
      }
  
  
      /**
       * Returns the message resources with the specified bundle name for this application
       * or <code>null</code> if not found.
       *
       * @param app the servlet context
       * @param bundle The bundle name to look for.  If this is <code>null</code>, the
       *               default bundle name is used.
       * @since VelocityTools 1.1
       */
      public static MessageResources getMessageResources(HttpServletRequest request,
                                                         ServletContext app,
                                                        String bundle)
     {
         /* Identify the current module */
         ModuleConfig moduleConfig = ModuleUtils.getInstance().getModuleConfig(request, app);
 
         if (bundle == null) {
             bundle = Globals.MESSAGES_KEY;
         }
 
         // First check request scope
         MessageResources resources =
             (MessageResources)request.getAttribute(bundle + moduleConfig.getPrefix());
 
         if (resources == null) {
             resources = (MessageResources) app.getAttribute(bundle + moduleConfig.getPrefix());
         }
         return resources;
     }
 
 
     /**
      * Select the module to which the specified request belongs, and
      * add return the corresponding ModuleConfig.
      *
      * @param urlPath The requested URL
      * @param app The ServletContext for this web application
      * @return The ModuleConfig for the given URL path
      * @since VelocityTools 1.1
      */
     public static ModuleConfig selectModule(String urlPath,
                                             ServletContext app)
     {
         /* Match against the list of sub-application prefixes */
         String prefix = ModuleUtils.getInstance().getModuleName(urlPath, app);
 
         /* Expose the resources for this sub-application */
         ModuleConfig config = (ModuleConfig)
             app.getAttribute(Globals.MODULE_KEY + prefix);
 
         return config;
     }
 
 
     /********************** Struts Session Resources ******************/
 
     /**
      * Returns the <code>java.util.Locale</code> for the user. If a
      * locale object is not found in the user's session, the system
      * default locale is returned.
      *
      * @param request the servlet request
      * @param session the HTTP session
      */
     public static Locale getLocale(HttpServletRequest request,
                                    HttpSession session)
     {
         Locale locale = null;
 
         if (session != null)
         {
             locale = (Locale)session.getAttribute(Globals.LOCALE_KEY);
         }
         if (locale == null)
         {
             locale = request.getLocale();
         }
         return locale;
     }
 
 
     /**
      * Returns the transaction token stored in this session or
      * <code>null</code> if not used.
      *
      * @param session the HTTP session
      */
     public static String getToken(HttpSession session)
     {
         if (session == null)
         {
             return null;
         }
         return (String)session.getAttribute(Globals.TRANSACTION_TOKEN_KEY);
     }
 
 
     /*********************** Struts Request Resources ****************/
 
     /**
      * Returns the Struts errors for this request or <code>null</code>
      * if none exist. Since VelocityTools 1.2, this will also check
      * the session (if there is one) for errors if there are no errors
      * in the request.
      *
      * @param request the servlet request
      * @since VelocityTools 1.1
      */
     public static ActionMessages getErrors(HttpServletRequest request)
     {
         ActionMessages errors = (ActionMessages)request.getAttribute(Globals.ERROR_KEY);
         if (errors == null || errors.isEmpty())
         {
             // then check the session
             HttpSession session = request.getSession(false);
             if (session != null)
             {
                 errors = (ActionMessages)session.getAttribute(Globals.ERROR_KEY);
             }
         }
         return errors;
     }
 
     /**
      * Returns the Struts messages for this request or <code>null</code>
      * if none exist.  Since VelocityTools 1.2, this will also check
      * the session (if there is one) for messages if there are no messages
      * in the request.
      *
      * @param request the servlet request
      * @since VelocityTools 1.1
      */
     public static ActionMessages getMessages(HttpServletRequest request)
     {
         ActionMessages messages = (ActionMessages)request.getAttribute(Globals.MESSAGE_KEY);
         if (messages == null || messages.isEmpty())
         {
             // then check the session
             HttpSession session = request.getSession(false);
             if (session != null)
             {
                 messages = (ActionMessages)session.getAttribute(Globals.MESSAGE_KEY);
             }
         }
         return messages;
     }
 
     /**
      * Returns the <code>ActionForm</code> bean associated with
      * this request of <code>null</code> if none exists.
      *
      * @param request the servlet request
      * @param session the HTTP session
      */
     public static ActionForm getActionForm(HttpServletRequest request,
                                            HttpSession session)
     {
         /* Is there a mapping associated with this request? */
         ActionConfig mapping =
             (ActionConfig)request.getAttribute(Globals.MAPPING_KEY);
         if (mapping == null)
         {
             return null;
         }
 
         /* Is there a form bean associated with this mapping? */
         String attribute = mapping.getAttribute();
         if (attribute == null)
         {
             return null;
         }
 
         /* Look up the existing form bean */
         if ("request".equals(mapping.getScope()))
         {
             return (ActionForm)request.getAttribute(attribute);
         }
         if (session != null)
         {
             return (ActionForm)session.getAttribute(attribute);
         }
         return null;
     }
 
     /**
      * Returns the ActionForm name associated with
      * this request of <code>null</code> if none exists.
      *
      * @param request the servlet request
      * @param session the HTTP session
      */
     public static String getActionFormName(HttpServletRequest request,
                                            HttpSession session)
     {
         /* Is there a mapping associated with this request? */
         ActionConfig mapping =
             (ActionConfig)request.getAttribute(Globals.MAPPING_KEY);
         if (mapping == null)
         {
             return null;
         }
 
         return mapping.getAttribute();
     }
 
 
 
     /*************************** Utilities *************************/
 
     /**
      * Return the form action converted into an action mapping path.  The
      * value of the <code>action</code> property is manipulated as follows in
      * computing the name of the requested mapping:
      * <ul>
      * <li>Any filename extension is removed (on the theory that extension
      *     mapping is being used to select the controller servlet).</li>
      * <li>If the resulting value does not start with a slash, then a
      *     slash is prepended.</li>
      * </ul>
      */
     public static String getActionMappingName(String action) {
 
         String value = action;
         int question = action.indexOf('?');
         if (question >= 0) {
             value = value.substring(0, question);
         }
 
         int slash = value.lastIndexOf('/');
         int period = value.lastIndexOf('.');
         if ((period >= 0) && (period > slash)) {
             value = value.substring(0, period);
         }
 
         return value.startsWith("/") ? value : ("/" + value);
     }
 
     /**
      * Returns the form action converted into a server-relative URI
      * reference.
      *
      * @param application the servlet context
      * @param request the servlet request
      * @param action the name of an action as per struts-config.xml
      */
     public static String getActionMappingURL(ServletContext application,
                                              HttpServletRequest request,
                                              String action)
     {
         StringBuilder value = new StringBuilder(request.getContextPath());
         ModuleConfig config =
             (ModuleConfig)request.getAttribute(Globals.MODULE_KEY);
         if (config != null)
         {
             value.append(config.getPrefix());
         }
 
         /* Use our servlet mapping, if one is specified */
         String servletMapping =
             (String)application.getAttribute(Globals.SERVLET_KEY);
 
         if (servletMapping != null)
         {
             String queryString = null;
             int question = action.indexOf('?');
 
             if (question >= 0)
             {
                 queryString = action.substring(question);
             }
 
             String actionMapping = TagUtils.getInstance().getActionMappingName(action);
 
             if (servletMapping.startsWith("*."))
             {
                 value.append(actionMapping);
                 value.append(servletMapping.substring(1));
             }
             else if (servletMapping.endsWith("/*"))
             {
                 value.append(servletMapping.substring
                              (0, servletMapping.length() - 2));
                 value.append(actionMapping);
             }
 
             if (queryString != null)
             {
                 value.append(queryString);
             }
         }
         else
         {
             /* Otherwise, assume extension mapping is in use and extension is
              * already included in the action property */
             if (!action.startsWith("/"))
             {
                 value.append("/");
             }
             value.append(action);
         }
 
         /* Return the completed value */
         return value.toString();
     }
 
 
     /**
      * Returns the action forward name converted into a server-relative URI
      * reference.
      *
      * @param app the servlet context
      * @param request the servlet request
      * @param forward the name of a forward as per struts-config.xml
      */
     public static String getForwardURL(HttpServletRequest request,
                                        ServletContext app,
                                        String forward)
     {
         ModuleConfig moduleConfig = ModuleUtils.getInstance().getModuleConfig(request, app);
         //TODO? beware of null module config if ActionServlet isn't init'ed?
 
         ActionConfig actionConfig =
             (ActionConfig)request.getAttribute(Globals.MAPPING_KEY);
 
         // NOTE: ActionConfig.findForwardConfig only searches local forwards
         ForwardConfig fc = null;
         if(actionConfig != null)
         {
             fc = actionConfig.findForwardConfig(forward);
         }
 
         // No ActionConfig forward?
         // Find the ForwardConfig in the global-forwards.
         if(fc == null)
         {
             fc = moduleConfig.findForwardConfig(forward);
 
             // ok, give up
             if (fc == null)
             {
                 return null;
             }
         }
 
         StringBuilder url = new StringBuilder();
         if (fc.getPath().startsWith("/"))
         {
             url.append(request.getContextPath());
             url.append(RequestUtils.forwardURL(request, fc, moduleConfig));
         }
         else
         {
             url.append(fc.getPath());
         }
         return url.toString();
     }
 
 
     /**
      * Returns a formatted error message. The error message is assembled from
      * the following three pieces: First, value of message resource
      * "errors.header" is prepended. Then, the list of error messages is
      * rendered. Finally, the value of message resource "errors.footer"
      * is appended.
      *
      * @param property the category of errors to markup and return
      * @param request the servlet request
      * @param session the HTTP session
      * @param application the servlet context
      *
      * @return The formatted error message. If no error messages are queued,
      * an empty string is returned.
      */
     public static String errorMarkup(String property,
                                      HttpServletRequest request,
                                      HttpSession session,
                                      ServletContext application)
     {
         return errorMarkup(property, null, request, session, application);
     }
 
 
     /**
      * Returns a formatted error message. The error message is assembled from
      * the following three pieces: First, value of message resource
      * "errors.header" is prepended. Then, the list of error messages is
      * rendered. Finally, the value of message resource "errors.footer"
      * is appended.
      *
      * @param property the category of errors to markup and return
      * @param bundle the message resource bundle to use
      * @param request the servlet request
      * @param session the HTTP session
      * @param application the servlet context
      * @since VelocityTools 1.1
      * @return The formatted error message. If no error messages are queued,
      * an empty string is returned.
      */
     public static String errorMarkup(String property,
                                      String bundle,
                                      HttpServletRequest request,
                                      HttpSession session,
                                      ServletContext application)
     {
         ActionMessages errors = getErrors(request);
         if (errors == null)
         {
             return "";
         }
 
         /* fetch the error messages */
         Iterator reports = null;
         if (property == null)
         {
             reports = errors.get();
         }
         else
         {
             reports = errors.get(property);
         }
 
         if (!reports.hasNext())
         {
             return "";
         }
 
         /* Render the error messages appropriately if errors have been queued */
         StringBuilder results = new StringBuilder();
         String header = null;
         String footer = null;
         String prefix = null;
         String suffix = null;
         Locale locale = getLocale(request, session);
 
         MessageResources resources =
             getMessageResources(request, application, bundle);
         if (resources != null)
         {
             header = resources.getMessage(locale, "errors.header");
             footer = resources.getMessage(locale, "errors.footer");
             prefix = resources.getMessage(locale, "errors.prefix");
             suffix = resources.getMessage(locale, "errors.suffix");
         }
         if (header == null)
         {
             header = "errors.header";
         }
         if (footer == null)
         {
             footer = "errors.footer";
         }
         /* prefix or suffix are optional, be quiet if they're missing */
         if (prefix == null)
         {
             prefix = "";
         }
         if (suffix == null)
         {
             suffix = "";
         }
 
         results.append(header);
         results.append("\r\n");
 
         String message;
         while (reports.hasNext())
         {
             message = null;
             ActionMessage report = (ActionMessage)reports.next();
             if (resources != null && report.isResource())
             {
                 message = resources.getMessage(locale,
                                                report.getKey(),
                                                report.getValues());
             }
 
             results.append(prefix);
 
             if (message != null)
             {
                 results.append(message);
             }
             else
             {
                 results.append(report.getKey());
             }
 
             results.append(suffix);
             results.append("\r\n");
         }
 
         results.append(footer);
         results.append("\r\n");
 
         /* return result */
         return results.toString();
     }
 
 }