/**
    * This file Copyright (c) 2003-2018 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.freemarker;
  
  import info.magnolia.freemarker.models.MagnoliaModelFactory;
  import info.magnolia.freemarker.models.MagnoliaObjectWrapper;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.inject.Singleton;
  
  import freemarker.cache.ClassTemplateLoader;
  import freemarker.cache.MultiTemplateLoader;
  import freemarker.cache.TemplateLoader;
  import freemarker.template.ObjectWrapper;
  import freemarker.template.TemplateExceptionHandler;
  import freemarker.template.TemplateModel;
  import freemarker.template.TemplateModelException;
  
  /**
   * Observed bean holding Freemarker configuration. Not to be confused with
   * Freemarker's own {@link freemarker.template.Configuration}. This only exposes the few
   * properties that Magnolia allows to configure and is able to handle properly.
   * It also provides a few additional methods used internally.
   *
   * @see info.magnolia.freemarker.FreemarkerHelper
   * @see info.magnolia.freemarker.models.MagnoliaObjectWrapper
   * @see info.magnolia.freemarker.models.MagnoliaModelFactory
   */
  @Singleton
  public class FreemarkerConfig {
  
      /**
       * The MagnoliaModelFactory implementations explicitly registered by modules.
       */
      private List<MagnoliaModelFactory> registeredModelFactories = new ArrayList<MagnoliaModelFactory>();
      private List<TemplateLoader> templateLoaders = new ArrayList<TemplateLoader>();
      private Map<String, TemplateModel> sharedVariables = new HashMap<String, TemplateModel>();
      private TemplateExceptionHandler templateExceptionHandler = TemplateExceptionHandler.IGNORE_HANDLER;
  
      private ObjectWrapper objectWrapper;
      private TemplateLoader multiTL;
  
      public FreemarkerConfig() {
      }
  
      public ObjectWrapper getObjectWrapper() {
          if (objectWrapper == null) {
              objectWrapper = newObjectWrapper();
          }
          return objectWrapper;
      }
  
      protected ObjectWrapper newObjectWrapper() {
          return new MagnoliaObjectWrapper(this);
      }
  
      public TemplateLoader getTemplateLoader() {
          // multiTL will be null every time the config is changed, since node2bean instantiates a new FreemarkerConfig
          if (multiTL == null) {
              // using getTemplateLoaders() instead of the variable to make sure we go to the proxied object
              final List<TemplateLoader> loaders = getTemplateLoaders();
              // Fall back to ClassTemplateLoader
              if (loaders.isEmpty()) {
                  multiTL = new ClassTemplateLoader(getClass(), "/");
             } else {
                 final TemplateLoader[] tl = loaders.toArray(new TemplateLoader[loaders.size()]);
                 multiTL = new MultiTemplateLoader(tl);
             }
         }
         return multiTL;
     }
 
     public List<MagnoliaModelFactory> getModelFactories() {
         return registeredModelFactories;
     }
 
     public void setModelFactories(List<MagnoliaModelFactory> registeredModelFactories) {
         this.registeredModelFactories.addAll(registeredModelFactories);
     }
 
     public List<TemplateLoader> getTemplateLoaders() {
         return templateLoaders;
     }
 
     public void setTemplateLoaders(List<TemplateLoader> templateLoaders) {
         this.templateLoaders.addAll(templateLoaders);
     }
 
     public Map<String, TemplateModel> getSharedVariables() {
         return sharedVariables;
     }
 
     public void setSharedVariables(Map<String, Object> configuredSharedVariables) throws TemplateModelException {
         for (Map.Entry<String, Object> sv : configuredSharedVariables.entrySet()) {
             sharedVariables.put(sv.getKey(), getObjectWrapper().wrap(sv.getValue()));
         }
     }
 
     // for tests
     void addSharedVariable(String name, Object value) throws TemplateModelException {
         sharedVariables.put(name, getObjectWrapper().wrap(value));
     }
 
     public TemplateExceptionHandler getTemplateExceptionHandler() {
         return templateExceptionHandler;
     }
 
     public void setTemplateExceptionHandler(TemplateExceptionHandler templateExceptionHandler) {
         this.templateExceptionHandler = templateExceptionHandler;
     }
 }