/**
    * Copyright (C) 2005-2009 Alfresco Software Limited.
    *
    * This file is part of the Spring Surf Extension project.
    *
    * 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.springframework.extensions.surf;
  
  import java.util.Collections;
  import java.util.Enumeration;
  
  import javax.servlet.GenericServlet;
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.springframework.beans.BeansException;
  import org.springframework.beans.factory.BeanInitializationException;
  import org.springframework.context.ApplicationContext;
  import org.springframework.context.ApplicationContextAware;
  import org.springframework.context.ApplicationEvent;
  import org.springframework.context.ApplicationListener;
  import org.springframework.context.event.ContextRefreshedEvent;
  import org.springframework.extensions.config.Config;
  import org.springframework.extensions.config.ConfigService;
  import org.springframework.extensions.config.RemoteConfigElement;
  import org.springframework.extensions.config.WebFrameworkConfigElement;
  import org.springframework.extensions.surf.render.RenderService;
  import org.springframework.extensions.surf.render.TagService;
  import org.springframework.extensions.surf.resource.ResourceService;
  import org.springframework.extensions.webscripts.Container;
  import org.springframework.extensions.webscripts.ScriptRemote;
  import org.springframework.extensions.webscripts.connector.ConnectorService;
  import org.springframework.web.context.ServletContextAware;
  import org.springframework.web.context.support.WebApplicationContextUtils;
  
  import freemarker.ext.jsp.TaglibFactory;
  import freemarker.ext.servlet.ServletContextHashModel;
  import freemarker.template.ObjectWrapper;
  
  /**
   * Service Registry for Web Framework
   * 
   * This service provides getters for all Web Framework services and
   * helper beans.
   * 
   * @author muzquiano
   */
  public class WebFrameworkServiceRegistry implements ApplicationContextAware, ServletContextAware, ApplicationListener
  {
      private static final Log logger = LogFactory.getLog(WebFrameworkServiceRegistry.class);
          
      private ApplicationContext applicationContext;
      private ServletContext servletContext;
          
      // web framework service registry singleton
      public static final String WEB_FRAMEWORK_SERVICE_REGISTRY_ID = "webframework.serviceregistry";
      
      // core service bean ids
      private static final String CONFIG_SERVICE_ID = "web.config";
      private static final String WEB_FRAMEWORK_MANAGER_ID = "webframework.manager";
      private static final String WEB_FRAMEWORK_RENDER_SERVICE_ID = "webframework.service.render";
      private static final String WEB_FRAMEWORK_RESOURCE_SERVICE_ID = "webframework.service.resource";
      private static final String WEB_FRAMEWORK_TAG_SERVICE_ID = "webframework.service.tag";
      private static final String CONNECTOR_SERVICE_ID = "connector.service";
      private static final String PRESETS_MANAGER_ID = "webframework.presets.manager";
      private static final String SCRIPT_REMOTE_ID = "webframework.webscripts.scriptremote";
      private static final String WEBFRAMEWORK_TEMPLATES_CONTAINER_ID = "webframework.templates.container";
      
      // core service beans
      private ConfigService configService;
      private WebFrameworkManager webFrameworkManager;
      private RenderService webFrameworkRenderService;
      private ResourceService webFrameworkResourceService;
      private TagService webFrameworkTagService;
      private ConnectorService connectorService;
      private PresetsManager presetsManager;
      private ScriptRemote scriptRemote;
      
      // extensible service bean ids
      private static final String PAGE_MAPPER_FACTORY_ID = "webframework.factory.pagemapper";
      private static final String LINK_BUILDER_FACTORY_ID = "webframework.factory.linkbuilder";
      private static final String USER_FACTORY_ID = "webframework.factory.userfactory";
     private static final String REQUEST_CONTEXT_FACTORY_ID = "webframework.factory.requestcontext";
     
     // extensible service beans
     private PageMapperFactory pageMapperFactory;
     private LinkBuilderFactory linkBuilderFactory;
     private UserFactory userFactory;
     private RequestContextFactory requestContextFactory;
     
     // configuration elements
     private RemoteConfigElement remoteConfigElement;
     private WebFrameworkConfigElement webFrameworkConfigElement;
     
     // web framework webscripts container
     private static final String WEBFRAMEWORK_WEBSCRIPTS_CONTAINER_ID = "webscripts.container";
     private Container webFrameworkContainer;
     
     // templates container
     private TemplatesContainer templatesContainer;
     
     // precomputed hash models for use by processors
     private static TaglibFactory taglibFactory;
     private static ServletContextHashModel servletContextHashModel;
     
         
     /**
      * Helper method for retrieving the service registry bound to the
      * current application context.
      * 
      * @return
      */
     public static WebFrameworkServiceRegistry getInstance(ServletContext servletContext)
     {
         ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(servletContext);
         
         return (WebFrameworkServiceRegistry) applicationContext.getBean(WEB_FRAMEWORK_SERVICE_REGISTRY_ID);
     }
     
     /* (non-Javadoc)
      * @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.ApplicationContext)
      */
     public void setApplicationContext(ApplicationContext applicationContext)
         throws BeansException
     {
         this.applicationContext = applicationContext;
     }
     
     /* (non-Javadoc)
      * @see org.springframework.web.context.ServletContextAware#setServletContext(javax.servlet.ServletContext)
      */
     public void setServletContext(ServletContext servletContext)
         throws BeansException
     {
         this.servletContext = servletContext;
     }
     
     /**
      * Gets the application context.
      * 
      * @return the application context
      */
     public ApplicationContext getApplicationContext()
     {
         return this.applicationContext;
     }
     
     /**
      * Gets the servlet context.
      * 
      * @return the servlet context
      */
     public ServletContext getServletContext()
     {
         return this.servletContext;
     }
     
     /**
      * Sets the request context factory.
      * 
      * @param requestContextFactory the new request context factory
      */
     public void setRequestContextFactory(RequestContextFactory requestContextFactory)
     {
         this.requestContextFactory = requestContextFactory;
     }
     
     /**
      * Sets the page mapper factory.
      * 
      * @param pageMapperFactory the new page mapper factory
      */
     public void setPageMapperFactory(PageMapperFactory pageMapperFactory)
     {
         this.pageMapperFactory = pageMapperFactory;
     }
     
     /**
      * Sets the link builder factory.
      * 
      * @param linkBuilderFactory the new link builder factory
      */
     public void setLinkBuilderFactory(LinkBuilderFactory linkBuilderFactory)
     {
         this.linkBuilderFactory = linkBuilderFactory;
     }
     
     /**
      * Sets the user factory.
      * 
      * @param userFactory the new user factory
      */
     public void setUserFactory(UserFactory userFactory)
     {
         this.userFactory = userFactory;
     }
     
     /* (non-Javadoc)
      * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
      */
     public void onApplicationEvent(ApplicationEvent event)
     {
         if (event instanceof ContextRefreshedEvent)
         {
             ContextRefreshedEvent refreshEvent = (ContextRefreshedEvent)event;            
             ApplicationContext refreshContext = refreshEvent.getApplicationContext();
             if (refreshContext != null && refreshContext.equals(getApplicationContext()))
             {
                 onBootstrap();
             }
         }
     }
     
     
     /**
      * Initialization of the Web Framework Service Registry
      */
     protected void onBootstrap()
     {
         // retrieve all core framework services        
         configService = (ConfigService) applicationContext.getBean(CONFIG_SERVICE_ID);
         webFrameworkManager = (WebFrameworkManager) applicationContext.getBean(WEB_FRAMEWORK_MANAGER_ID);
         webFrameworkRenderService = (RenderService) applicationContext.getBean(WEB_FRAMEWORK_RENDER_SERVICE_ID);
         webFrameworkResourceService = (ResourceService) applicationContext.getBean(WEB_FRAMEWORK_RESOURCE_SERVICE_ID);
         webFrameworkTagService = (TagService) applicationContext.getBean(WEB_FRAMEWORK_TAG_SERVICE_ID);
         connectorService = (ConnectorService) applicationContext.getBean(CONNECTOR_SERVICE_ID);
         presetsManager = (PresetsManager) applicationContext.getBean(PRESETS_MANAGER_ID);
         scriptRemote = (ScriptRemote) applicationContext.getBean(SCRIPT_REMOTE_ID);
         
         // web framework container
         webFrameworkContainer = (Container) applicationContext.getBean(WEBFRAMEWORK_WEBSCRIPTS_CONTAINER_ID);
         
         // template container
         templatesContainer = (TemplatesContainer) applicationContext.getBean(WEBFRAMEWORK_TEMPLATES_CONTAINER_ID);
         
         // retrieve configuration elements
         Config remoteConfig = configService.getConfig("Remote");
         remoteConfigElement = (RemoteConfigElement) remoteConfig.getConfigElement("remote");
         Config webFrameworkConfig = configService.getConfig("WebFramework");
         webFrameworkConfigElement = (WebFrameworkConfigElement) webFrameworkConfig.getConfigElement("web-framework");
         
         // extensible services
         // use defaults if not otherwise set
         if (pageMapperFactory == null)
         {
             pageMapperFactory = (PageMapperFactory) applicationContext.getBean(PAGE_MAPPER_FACTORY_ID);
         }
         if (linkBuilderFactory == null)
         {
             linkBuilderFactory = (LinkBuilderFactory) applicationContext.getBean(LINK_BUILDER_FACTORY_ID);
         }
         if (userFactory == null)
         {
             userFactory = (UserFactory) applicationContext.getBean(USER_FACTORY_ID);
         }
         if (requestContextFactory == null)
         {
             requestContextFactory = (RequestContextFactory) applicationContext.getBean(REQUEST_CONTEXT_FACTORY_ID);
         }
         
         // build tag library container
         taglibFactory = new TaglibFactory(servletContext);
 
         // build the servlet context hash model
         GenericServlet servlet = new GenericServletAdapter();
         try {
             servlet.init(new DelegatingServletConfig(servletContext));
         }
         catch (ServletException ex) {
             throw new BeanInitializationException("Initialization of GenericServlet adapter failed", ex);
         }        
         servletContextHashModel = new ServletContextHashModel(servlet, ObjectWrapper.DEFAULT_WRAPPER);        
     }
     
     /**
      * Gets the config service.
      * 
      * @return the config service
      */
     public ConfigService getConfigService()
     {
         return this.configService;
     }
     
     /**
      * Gets the web framework manager.
      * 
      * @return the web framework manager
      */
     public WebFrameworkManager getWebFrameworkManager()
     {
         return this.webFrameworkManager;
     }
 
     /**
      * Gets the web framework render service.
      * 
      * @return the web framework render service
      */
     public RenderService getRenderService()
     {
         return this.webFrameworkRenderService;
     }
     
     /**
      * Gets the resource service.
      * 
      * @return the resource service
      */
     public ResourceService getResourceService()
     {
         return this.webFrameworkResourceService;
     }
     
     /**
      * Gets the tag service.
      * 
      * @return the tag service
      */
     public TagService getTagService()
     {
         return this.webFrameworkTagService;
     }
     
     /**
      * Gets the connector service.
      * 
      * @return the connector service
      */
     public ConnectorService getConnectorService()
     {
         return this.connectorService;
     }
     
     /**
      * Gets the presets manager.
      * 
      * @return the presets manager
      */
     public PresetsManager getPresetsManager()
     {
         return this.presetsManager;
     }
     
     /**
      * Gets the script remote.
      * 
      * @return the script remote
      */
     public ScriptRemote getScriptRemote()
     {
         return this.scriptRemote;
     }
     
     /**
      * Gets the remote configuration.
      * 
      * @return the remote configuration
      */
     public RemoteConfigElement getRemoteConfiguration()
     {
         return this.remoteConfigElement;
     }
     
     /**
      * Gets the web framework configuration.
      * 
      * @return the web framework configuration
      */
     public WebFrameworkConfigElement getWebFrameworkConfiguration()
     {
         return this.webFrameworkConfigElement;
     }
     
     /**
      * Gets the page mapper factory.
      * 
      * @return the page mapper factory
      */
     public PageMapperFactory getPageMapperFactory()
     {
         return this.pageMapperFactory;
     }
     
     /**
      * Gets the link builder factory.
      * 
      * @return the link builder factory
      */
     public LinkBuilderFactory getLinkBuilderFactory()
     {
         return this.linkBuilderFactory;
     }
     
     /**
      * Gets the user factory.
      * 
      * @return the user factory
      */
     public UserFactory getUserFactory()
     {
         return this.userFactory;
     }
     
     /**
      * Gets the request context factory.
      * 
      * @return the request context factory
      */
     public RequestContextFactory getRequestContextFactory()
     {
         return this.requestContextFactory;
     }
     
     /**
      * Gets the web framework container.
      * 
      * @return the web framework container
      */
     public Container getWebFrameworkContainer()
     {
         return this.webFrameworkContainer;
     }
     
     /**
      * Gets the templates container.
      * 
      * @return the templates container
      */
     public TemplatesContainer getTemplatesContainer()
     {
         return this.templatesContainer;
     }
     
     /**
      * Gets the taglib factory.
      * 
      * @return the taglib factory
      */
     public TaglibFactory getTaglibFactory()
     {
         return taglibFactory;
     }
     
     /**
      * Gets the servlet context hash model.
      * 
      * @return the servlet context hash model
      */
     public ServletContextHashModel getServletContextHashModel()
     {
         return servletContextHashModel;
     }        
     
     /**
      * Simple adapter class that extends {@link GenericServlet}.
      * Needed to support generic JSP tag libraries in FreeMarker.
      */
     private class GenericServletAdapter extends GenericServlet 
     {
         public void service(ServletRequest servletRequest, ServletResponse servletResponse) 
         {
             // no-op
         }
     }
 
     /**
      * Internal implementation of the {@link ServletConfig} interface,
      * to be passed to the servlet adapter.
      */
     private class DelegatingServletConfig implements ServletConfig 
     {
         private ServletContext servletContext = null;
         
         public DelegatingServletConfig(ServletContext servletContext)
         {
             this.servletContext = servletContext;
         }
         
         public String getServletName() 
         {
             return FrameworkUtil.class.getSimpleName();
         }
 
         public ServletContext getServletContext() 
         {
             return servletContext;
         }
 
         public String getInitParameter(String paramName) 
         {
             return null;
         }
 
         public Enumeration getInitParameterNames() 
         {
             return Collections.enumeration(Collections.EMPTY_SET);
         }
     }
 }