/**
    * This file Copyright (c) 2015 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.pages.app;
  
  import info.magnolia.cms.core.Path;
  import info.magnolia.context.SystemContext;
  import info.magnolia.i18nsystem.SimpleTranslator;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.objectfactory.ComponentProvider;
  import info.magnolia.rendering.template.TemplateAvailability;
  import info.magnolia.rendering.template.TemplateDefinition;
  import info.magnolia.rendering.template.registry.TemplateDefinitionRegistry;
  import info.magnolia.repository.RepositoryConstants;
  import info.magnolia.ui.api.app.AppContext;
  import info.magnolia.ui.api.app.AppView;
  import info.magnolia.ui.api.location.Location;
  import info.magnolia.ui.api.overlay.AlertCallback;
  import info.magnolia.ui.contentapp.ContentApp;
  import info.magnolia.ui.vaadin.overlay.MessageStyleTypeEnum;
  
  import java.util.Iterator;
  
  import javax.inject.Inject;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * The Pages content app displays an alert when no templates are installed to help beginners.
   *
   * @see ContentApp
   */
  public class PagesContentApp extends ContentApp {
  
      private static final Logger log = LoggerFactory.getLogger(PagesContentApp.class);
  
      private final TemplateDefinitionRegistry templateDefinitionRegistry;
      private final TemplateAvailability templateAvailability;
      private final SimpleTranslator i18n;
      private final SystemContext systemContext;
  
      private static final String HELP_URL = "https://documentation.magnolia-cms.com/display/DOCS54/Get+templates";
  
      @Inject
      public PagesContentApp(AppContext appContext, AppView view, ComponentProvider componentProvider, TemplateDefinitionRegistry templateDefinitionRegistry, TemplateAvailability templateAvailability, SimpleTranslator i18n, SystemContext systemContext) {
          super(appContext, view, componentProvider);
          this.templateDefinitionRegistry = templateDefinitionRegistry;
          this.templateAvailability = templateAvailability;
          this.i18n = i18n;
          this.systemContext = systemContext;
      }
  
      @Override
      public void start(Location location) {
          super.start(location);
  
          // Display an alert with a help message if no page templates are available.
          if (!hasAvailablePageTemplates()) {
              final String templateAvailabilityMessage = i18n.translate("pages.noAvailableTemplatesAlert.templateAvailabilityMessage");
              final String createTemplateLink = i18n.translate("pages.noAvailableTemplatesAlert.createTemplateLink", HELP_URL);
              final String message = templateAvailabilityMessage + createTemplateLink;
              getAppContext().openAlert(MessageStyleTypeEnum.INFO, i18n.translate("pages.noAvailableTemplatesAlert.title"), message, i18n.translate("button.ok"), new AlertCallback() {
                  @Override
                  public void onOk() {
                      // Do nothing.
                 }
             });
         }
     }
 
     /**
      * Returns whether any page templates are available.
      */
     protected boolean hasAvailablePageTemplates() {
         boolean hasAvailablePageTemplates = false;
 
         try {
             // Get root node
             final Session session = systemContext.getJCRSession(RepositoryConstants.WEBSITE);
             final Node websiteRootNode = session.getRootNode();
 
             // Create tmp node
             final String tempNodeName = Path.getUniqueLabel(websiteRootNode, "tmp");
             final Node tempNode = websiteRootNode.addNode(tempNodeName, NodeTypes.Page.NAME);
 
             // Test availability on tmp node
             final Iterator<TemplateDefinition> iterator = templateDefinitionRegistry.getAllDefinitions().iterator();
 
             while (iterator.hasNext()) {
                 final TemplateDefinition templateDefinition = iterator.next();
                 if (templateAvailability.isAvailable(tempNode, templateDefinition)) {
                     hasAvailablePageTemplates = true;
                     break;
                 }
             }
 
             // Remove tmp node
             session.removeItem(tempNode.getPath());
         } catch (RepositoryException e) {
             log.error("Failed to retrieve website workspace or create temporary node when trying to determine available page templates.", e);
         }
 
         return hasAvailablePageTemplates;
     }
 
 }