/*
    * Copyright 2000-2004 The Apache Software Foundation.
    * 
    * Licensed 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.
   */
  
  package org.apache.jetspeed.modules.pages;
  
  // Turbine Modules
  import org.apache.turbine.modules.pages.DefaultPage;
  
  // Turbine Utility Classes
  import org.apache.turbine.util.RunData;
  import org.apache.turbine.services.template.TurbineTemplate;
  
  // Jetspeed Classes
  import org.apache.jetspeed.util.MimeType;
  import org.apache.jetspeed.om.registry.MediaTypeEntry;
  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
  import org.apache.jetspeed.services.logging.JetspeedLogger;
  import org.apache.jetspeed.services.Registry;
  import org.apache.jetspeed.capability.CapabilityMap;
  import org.apache.jetspeed.services.TemplateLocator;
  import org.apache.jetspeed.services.rundata.JetspeedRunData;
  import org.apache.jetspeed.services.resources.JetspeedResources;
  
  /***
   * When building sites using templates, Screens need only be defined
   * for templates which require dynamic (database or object) data.
   *
   * <p>
   *
   * This page can be used on sites where the number of Screens can be
   * much less than the number of templates.  The templates can be
   * grouped in directories with common layouts.  Screen modules are
   * then expected to be placed in packages corresponding with the
   * templates' directories and follow a specific naming scheme.
   *
   * <p>
   *
   * The template parameter is parsed and and a Screen whose package
   * matches the templates path and shares the same name minus any
   * extension and beginning with a capital letter is searched for.  If
   * not found, a Screen in a package matching the template's path with
   * name Default is searched for.  If still not found, a Screen with
   * name Default is looked for in packages corresponding to parent
   * directories in the template's path until a match is found.
   *
   * <p>
   *
   * For example if data.getParameters().getString("template") returns
   * /about_us/directions/driving.wm, the search follows
   * about_us.directions.Driving, about_us.directions.Default,
   * about_us.Default, Default, WebMacroSiteScreen (i.e. the default
   * screen set in TurbineResources).
   *
   * <p>
   *
   * Only one Layout module is used, since it is expected that any
   * dynamic content will be placed in navigations and screens.  The
   * layout template to be used is found in a similar way to the Screen.
   * For example the following paths will be searched in the layouts
   * subdirectory: /about_us/directions/driving.wm,
   * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,
   * where wm is the value of the template.default.extension property.
   *
   * <p>
   *
   * This approach allows a site with largely static content to be
   * updated and added to regularly by those with little Java
   * experience.
   *
   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
   * @author <a href="mailto:paulsp@apache.org">Paul Spencer</a>
   * @version $Id: JetspeedTemplatePage.java,v 1.24 2004/02/23 02:59:52 jford Exp $
   */
  public class JetspeedTemplatePage extends DefaultPage
  {
      private static int httpLifetime = JetspeedResources.getInt("http.lifetime", -1);
  
      /***
       * Static initialization of the logger for this class
       */    
      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(JetspeedTemplatePage.class.getName());     
      
      /***
       * Works with TemplateService to set up default templates and
       * corresponding class modules.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     protected void doBuildBeforeAction(RunData data) throws Exception
     {
         switch (httpLifetime)
         {
             case -1:
                 break;
             case 0:
                 data.getResponse().setHeader("Cache-Control", "no-cache");
                 data.getResponse().setHeader("Pragma", "no-cache");
                 data.getResponse().setDateHeader("Expires", 0);
                 data.getResponse().setDateHeader("Last-Modified", System.currentTimeMillis());
                 break;
             default:
                 data.getResponse().setHeader("Cache-Control", "max-age=" + httpLifetime);
                 data.getResponse().setDateHeader("Expires", System.currentTimeMillis() + (httpLifetime * 1000));
                 data.getResponse().setDateHeader("Last-Modified", System.currentTimeMillis());
                 break;
         }
 
         //Set the ContentType of the page
         CapabilityMap cm = ((JetspeedRunData)data).getCapability();
         MimeType mime = cm.getPreferredType();
         String characterSet = JetspeedResources.getString(JetspeedResources.CONTENT_ENCODING_KEY,"utf-8");
         data.setContentType( mime.getContentType());
         if ( mime != null )
         {
             MediaTypeEntry media = (MediaTypeEntry)Registry.getEntry(Registry.MEDIA_TYPE, mime.getCode());
             if ( media != null && media.getCharacterSet() != null)
             {
                 characterSet = media.getCharacterSet();
             }
         }
         data.setCharSet( characterSet );
 
         if (logger.isDebugEnabled())
         {
             logger.debug( "JetspeedTemplatePage: Setting type to: " + cm.getPreferredType().getContentType()
                         + "; charset=" + JetspeedResources.getString(JetspeedResources.CONTENT_ENCODING_KEY,"utf-8")
                      );
         }
 
     }
 
     /***
      * Works with TemplateService to set up default templates and
      * corresponding class modules.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     protected void doBuildAfterAction(RunData data) throws Exception
     {
         // Either template or screen should be guaranteed by the SessionValidator
         // It is occasionally better to specify the screen instead of template
         // in cases where multiple Screens map to one template.  The template
         // is hardcoded into the Screen in this instance.  In this case this
         // action is skipped.
 
         if (!data.hasScreen())
         {
 
             // if only a screen but no template is specified, then we need to display
             // a legacy ecs screen --> screenTemplate = ECS
             if ( data.getTemplateInfo().getScreenTemplate() == null )
             {
                 String screen = TurbineTemplate.getDefaultScreen();
                 data.setScreenTemplate(screen);
             }
 
             String ext = TurbineTemplate.getDefaultExtension();
 
             String template = data.getTemplateInfo().getScreenTemplate();
 
             //save the initial requested template before mangling it
             ((JetspeedRunData)data).setRequestedTemplate(template);
 
             if (template.lastIndexOf('.')<0)
             {
                 template=template+"."+ext;
             }
             if ( logger.isDebugEnabled() )
             {
                 logger.debug("JetspeedTemplatePage: requested template = " + template);
             }
 
             // get real path now - this is a fix to get us thru 1.3a2
             // when the TurbineTemplateService can locate resources by NLS and mediatype,
             // then it can be removed
 
             String locatedScreen = TemplateLocator.locateScreenTemplate(data, template);
             data.setScreenTemplate( locatedScreen );
             if ( logger.isDebugEnabled() )
             {
                 logger.debug("JetspeedTemplatePage: calculated template = " + locatedScreen);
             }
 
             String layout = TemplateLocator.locateLayoutTemplate(data, template);
             data.setLayoutTemplate(layout);
             if ( logger.isDebugEnabled() )
             {
                 logger.debug("JetspeedTemplatePage: layoutTemplate is finally " + layout);
             }
 
             String screen = TurbineTemplate.getScreenName(template);
             if (screen == null)
             {
                 throw new Exception("Screen could not be determined. \n" +
                     "No matches were found by TemplateService and the \n" +
                     "services.TurbineTemplateService.default.screen \n" +
                     "property was not set.");
             }
             data.setScreen(screen);
         }
     }
 
 }