/**
    * This file Copyright (c) 2016-2018 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.imaging;
  
  import java.io.IOException;
  
  import javax.inject.Inject;
  import javax.inject.Provider;
  import javax.jcr.LoginException;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import info.magnolia.context.SystemContext;
  import info.magnolia.imaging.caching.CachingImageStreamer;
  import info.magnolia.imaging.caching.CachingStrategy;
  import info.magnolia.objectfactory.annotation.LazySingleton;
  
  /**
   * The entry point to Imaging module.
   *
   * @see info.magnolia.imaging.ImagingServlet
   */
  @LazySingleton
  public class Imaging {
      private final ImagingModule config;
  
      private final Provider<SystemContext> contextProvider;
  
      @Inject
      public Imaging(ImagingModule config, Provider<SystemContext> contextProvider) {
          this.config = config;
          this.contextProvider = contextProvider;
      }
  
      public <ENV, PT> void generate(String generatorName, ENV input, ImageResponse imageResponse) throws IOException, ImagingException {
          final ImageGenerator<ParameterProvider<PT>> generator = getGenerator(generatorName);
          if (generator == null) {
              throw new IllegalArgumentException("No ImageGenerator with name " + generatorName);
          }
  
          final ParameterProviderFactory<ENV, PT> parameterProviderFactory = generator.getParameterProviderFactory();
          final ParameterProvider<PT> p = parameterProviderFactory.newParameterProviderFor(input);
  
          final ImageStreamer<PT> streamer = getStreamer(parameterProviderFactory);
          streamer.serveImage(generator, p, imageResponse);
      }
  
      protected ImageGenerator getGenerator(String generatorName) {
          return config.getGenerators().get(generatorName);
      }
  
      protected <E, PT> ImageStreamer<PT> getStreamer(ParameterProviderFactory<E, PT> parameterProviderFactory) {
          final DefaultImageStreamer<PT> newDefaultImageStreamer = new DefaultImageStreamer<PT>();
          if (!config.isStoreGeneratedImages()) {
              return newDefaultImageStreamer;
          } else {
              Session session;
              try {
                  session = contextProvider.get().getJCRSession(ImagingModule.IMAGING);
                  final CachingStrategy<PT> cachingStrategy = parameterProviderFactory.getCachingStrategy();
                  return new CachingImageStreamer<PT>(session, cachingStrategy, newDefaultImageStreamer, contextProvider.get());
              } catch (LoginException e) {
                  throw new RuntimeException("Could not connect to imaging repository.", e);
              } catch (RepositoryException e) {
                  throw new RuntimeException("Could not connect to imaging repository.", e);
              }
          }
      }
 
 }