/*
    * File:    Page.java
    * Created: 5.11.2006 16:10:24
    *
    * Copyright 2006 Michal Burda.
    *
    * This program is free software; you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  
  package net.sf.webmancer.widget;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import net.sf.webmancer.base.ApplicationInformation;
  import net.sf.webmancer.base.Event;
  import net.sf.webmancer.base.FinalizationEvent;
  import net.sf.webmancer.base.IApplicationInformation;
  import net.sf.webmancer.base.IEventQueue;
  import net.sf.webmancer.base.InitializationEvent;
  import net.sf.webmancer.base.RequestEvent;
  import net.sf.webmancer.model.IModelBuilder;
  import net.sf.webmancer.model.IModeler;
  import net.sf.webmancer.model.ModelingException;
  import net.sf.webmancer.util.ContractChecker;
  
  import org.springframework.web.servlet.ModelAndView;
  import org.springframework.web.servlet.mvc.Controller;
  
  /**
   * @author Michal Burda
   */
  public class Page extends AbstractContainer implements Controller {
      /**
       * 
       */
      public static final String PAGE_ELEMENT = "Page";
  
      /**
       * 
       */
      public static final String AUTHOR_ATTRIBUTE = "author";
  
      /**
       * 
       */
      public static final String APPLICATION_VERSION_ATTRIBUTE = "applicationVersion";
  
      /**
       * 
       */
      public static final String APPLICATION_TITLE_ATTRIBUTE = "applicationTitle";
  
      /**
       * 
       */
      public static final String PAGE_TITLE_ATTRIBUTE = "pageTitle";
  
      /**
       * 
       */
      private static final String DESCRIPTION_ATTRIBUTE = "description";
  
      /**
       * 
       */
      private static final String KEYWORDS_ATTRIBUTE = "keywords";
  
      /**
       * 
       */
      private String title;
      
      /**
       * 
       */
      private String keywords;
  
      /**
       * 
       */
      private String description;
  
      /**
      * 
      */
     private IApplicationInformation applicationInformation;
     
     /**
      * 
      */
     private IModeler modeler;
     
     /**
      * 
      */
     private IEventQueue eventQueue;
     
     /**
      * @param id
      * @param title
      */
     public Page() {
         super();
         this.title = "";
         this.applicationInformation = new ApplicationInformation();
     }
 
     /**
      * @see net.sf.webmancer.widget.AbstractWidget#setParent(net.sf.webmancer.widget.IWidget)
      */
     @Override
     public void setParent(IWidget parent) {
         // Page should always be a root widget (without any parent)
         throw new IllegalStateException("Cannot set parent widget of the " + this.getClass().getName() + " widget");
     }
 
     /**
      * Returns the description.
      *
      * @return the description
      */
     public String getDescription() {
         return this.description;
     }
 
     /**
      * Sets the description.
      *
      * @param description the description to set
      */
     public void setDescription(final String description) {
         this.description = description;
     }
     
     /**
      * Returns the keywords.
      *
      * @return the keywords
      */
     public String getKeywords() {
         return this.keywords;
     }
     
     /**
      * Sets the keywords.
      *
      * @param keywords the keywords to set
      */
     public void setKeywords(final String keywords) {
         this.keywords = keywords;
     }
     
     /**
      * Gets the title.
      * @return the title
      */
     public String getTitle() {
         return title;
     }
 
     /**
      * Sets the title.
      * @param title the title to set
      */
     public void setTitle(String title) {
         ContractChecker.mustNotBeNull(title, "title");
         this.title = title;
     }
     
     /**
      * Returns the applicationInformation.
      *
      * @return the applicationInformation
      */
     public IApplicationInformation getApplicationInformation() {
         return this.applicationInformation;
     }
 
     /**
      * Sets the applicationInformation.
      *
      * @param applicationInformation the applicationInformation to set
      */
     public void setApplicationInformation(IApplicationInformation applicationInformation) {
         ContractChecker.mustNotBeNull(applicationInformation, "applicationInformation");
         this.applicationInformation = applicationInformation;
     }
     
     /**
      * Returns the modeler.
      *
      * @return the modeler
      */
     protected IModeler getModeler() {
         return this.modeler;
     }
 
     /**
      * Sets the modeler.
      *
      * @param modeler the modeler to set
      */
     public void setModeler(IModeler modeler) {
         this.modeler = modeler;
     }
 
     /**
      * Returns the eventQueue.
      *
      * @return the eventQueue
      */
     protected IEventQueue getEventQueue() {
         return this.eventQueue;
     }
 
     /**
      * Sets the eventQueue.
      *
      * @param eventQueue the eventQueue to set
      */
     public void setEventQueue(IEventQueue eventQueue) {
         this.eventQueue = eventQueue;
     }
 
     /**
      * @see net.sf.webmancer.widget.AbstractWidget#putEvent(net.sf.webmancer.base.Event)
      */
     @Override
     public void putEvent(Event event) {
         ContractChecker.mustNotBeNull(event, "event");
         this.eventQueue.putEvent(event);
     }
 
     /**
      * @see net.sf.webmancer.widget.AbstractContainer#build(net.sf.webmancer.model.IModelBuilder)
      */
     @Override
     public void build(final IModelBuilder builder) throws ModelingException {
         Map<String, String> attributes = new HashMap<String, String>();
         attributes.put(PAGE_TITLE_ATTRIBUTE, this.title);
         attributes.put(APPLICATION_TITLE_ATTRIBUTE, this.applicationInformation.getTitle());
         attributes.put(APPLICATION_VERSION_ATTRIBUTE, this.applicationInformation.getVersion());
         attributes.put(AUTHOR_ATTRIBUTE, this.applicationInformation.getAuthor());
         if (getKeywords() != null) {
             attributes.put(KEYWORDS_ATTRIBUTE, getKeywords());
         }
         if (getDescription() != null) {
             attributes.put(DESCRIPTION_ATTRIBUTE, getDescription());
         }
         builder.startElement(IModeler.WEBMANCER_NAMESPACE, PAGE_ELEMENT, attributes);
         super.build(builder);
         builder.endElement();
     }
 
     /**
      * @see org.springframework.web.servlet.mvc.Controller#handleRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
      */
     public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
         processEventLoop(createInitializationEvent());
         processEventLoop(createRequestEvent(request, response));
         ModelAndView mv = processModeling();
         processEventLoop(createFinalizationEvent());
         return mv;
     }
 
     /**
      * @param event
      */
     protected void processEventLoop(Event event) {
         this.eventQueue.putEvent(event);
         while (this.eventQueue.hasEvents()) {
             Event next = this.eventQueue.nextEvent();
             this.handleEvent(next);
         }
     }
 
     /**
      * @return
      */
     protected ModelAndView processModeling() throws ModelingException {
         return this.getModeler().createModel(this);
     }
 
     /**
      * @return
      */
     protected Event createInitializationEvent() {
         return new InitializationEvent();
     }
 
     /**
      * @param request
      * @param response
      * @return
      */
     protected Event createRequestEvent(HttpServletRequest request, HttpServletResponse response) {
         return new RequestEvent(null);
     }
 
     /**
      * @return
      */
     private Event createFinalizationEvent() {
         return new FinalizationEvent();
     }
 
 }