/**
    * This file Copyright (c) 2003-2011 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.module.templating;
  
  import freemarker.core.Environment;
  import info.magnolia.cms.beans.config.ServerConfiguration;
  import info.magnolia.cms.core.Content;
  import info.magnolia.cms.core.NodeData;
  import info.magnolia.cms.i18n.I18nContentWrapper;
  import info.magnolia.cms.util.ContentUtil;
  import info.magnolia.cms.util.InheritanceContentWrapper;
  import info.magnolia.cms.util.SiblingsHelper;
  import info.magnolia.context.MgnlContext;
  import info.magnolia.link.LinkUtil;
  import info.magnolia.link.LinkException;
  import info.magnolia.module.templating.engine.RenderingEngine;
  import info.magnolia.objectfactory.Components;
  import info.magnolia.repository.RepositoryConstants;
  
  import javax.inject.Inject;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.lang.exception.ExceptionUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.io.Writer;
  
  /**
   * This is an object exposing a couple of methods useful for templates; it's exposed in
   * templates as "mgnl".
   *
   * @author gjoseph
   * @version $Revision: $ ($Author: $)
   */
  public class MagnoliaTemplatingUtilities {
  
      private static final Logger log = LoggerFactory.getLogger(MagnoliaTemplatingUtilities.class);
  
      protected RenderingEngine renderingEngine;
  
      @Inject
      public MagnoliaTemplatingUtilities(RenderingEngine renderingEngine) {
          this.renderingEngine = renderingEngine;
      }
  
      public static MagnoliaTemplatingUtilities getInstance(){
          return Components.getSingleton(MagnoliaTemplatingUtilities.class);
      }
  
      /**
       * Returns an instance of SiblingsHelper for the given node.
       */
      public SiblingsHelper siblings(Content node) throws RepositoryException {
          return SiblingsHelper.of(node);
      }
  
      public void renderTemplate(Content content) throws RenderException, IOException {
          renderTemplate(content, getWriter());
      }
  
      public void renderTemplate(Content content, Writer out) throws RenderException, IOException {
          renderingEngine.render(content, out);
      }
  
      public void renderTemplate(Content content, Writer out, String templateName) throws RenderException, IOException {
         renderingEngine.render(content, templateName, out);
     }
 
     public void renderParagraph(Content paragraphNode) throws RenderException, IOException {
         renderParagraph(paragraphNode, getWriter());
     }
 
     public void renderParagraph(Content paragraphNode, Writer out) throws RenderException, IOException {
         renderingEngine.render(paragraphNode, out);
     }
 
     public void renderParagraph(Content paragraphNode, Writer out, String paragraphName) throws RenderException, IOException {
         renderingEngine.render(paragraphNode, paragraphName, out);
     }
 
     /**
      * TODO each renderer should provide its own subclass.
      */
     protected Writer getWriter() {
         final Environment env = Environment.getCurrentEnvironment();
         return env.getOut();
     }
 
     public Content inherit(Content node) {
         return new InheritanceContentWrapper(node);
     }
 
     public Content i18n(Content node) {
         return new I18nContentWrapper(node);
     }
 
     public boolean isEditMode(){
         // TODO : see CmsFunctions.isEditMode, which checks a couple of other properties.
         return isAuthorInstance() && !isPreviewMode();
     }
 
     public boolean isPreviewMode(){
         return MgnlContext.getAggregationState().isPreviewMode();
     }
 
     public boolean isAuthorInstance(){
         return ServerConfiguration.getInstance().isAdmin();
     }
 
     public boolean isPublicInstance(){
         return !isAuthorInstance();
     }
 
     public String createLink(Content node) {
         return LinkUtil.createLink(node);
     }
 
     public String createLink(NodeData nd) {
         try {
             return LinkUtil.createLink(nd);
         } catch (LinkException e) {
             log.error("Can't resolve link defined in node {} because of {}.", nd.getHandle(), ExceptionUtils.getRootCauseMessage(e));
             return null;
         }
     }
 
     public String createLink(String repositoryId, String uuid) {
         try {
             return LinkUtil.createLink(repositoryId, uuid);
         } catch (RepositoryException e) {
             log.error("Can't resolve link with UUID {} because of {}.", uuid , ExceptionUtils.getRootCauseMessage(e));
             return null;
         }
     }
 
     /**
      * Util method to create html attributes <code>name="value"</code>. If the value is empty an empty string will be returned.
      * This is mainlly helpful to avoid empty attributes.
      */
     public String createAttribute(String name, String value){
         value = StringUtils.trim(value);
         if(StringUtils.isNotEmpty(value)){
             return new StringBuffer().append(name).append("=\"").append(value).append("\"").toString();
         }
         return StringUtils.EMPTY;
     }
 
     public Content getContent(String path){
       return getContent(RepositoryConstants.WEBSITE, path);
     }
 
     public Content getContent(String repository, String path){
         return ContentUtil.getContent(repository, path);
     }
 
     public Content getContentByUUID(String uuid){
         return getContentByUUID(RepositoryConstants.WEBSITE, uuid);
     }
 
     public Content getContentByUUID(String repository, String uuid){
         return ContentUtil.getContentByUUID(repository, uuid);
     }
 
     public static Content encode(Content content){
         if(content != null){
             return new HTMLEncodingContentWrapper(content, true);
         }
         return null;
     }
 
     public static Content decode(Content content){
         if(content instanceof HTMLEncodingContentWrapper){
             return ((HTMLEncodingContentWrapper)content).getWrappedContent();
         }
         throw new IllegalStateException("The content to decode is not wrapped by a " + HTMLEncodingContentWrapper.class.getName());
     }
 
 }