/**
    * This file Copyright (c) 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.rendering.template.registry;
  
  import info.magnolia.cms.core.MgnlNodeType;
  import info.magnolia.jcr.util.MetaDataUtil;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.objectfactory.Components;
  import info.magnolia.registry.AbstractRegistry;
  import info.magnolia.registry.RegistrationException;
  import info.magnolia.rendering.template.TemplateDefinition;
  import info.magnolia.rendering.template.assignment.TemplateDefinitionAssignment;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Map;
  
  import javax.inject.Inject;
  import javax.inject.Singleton;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.apache.commons.lang.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  
  /**
   * The central registry of all {@link TemplateDefinition}s.
   *
   * @version $Id$
   */
  @Singleton
  public class TemplateDefinitionRegistry extends AbstractRegistry<TemplateDefinition, TemplateDefinitionProvider>{
  
      private static final Logger log = LoggerFactory.getLogger(TemplateDefinitionRegistry.class);
      //FIXME this probably should not be hardcoded.
      private static final String DELETED_PAGE_TEMPLATE = "adminInterface:mgnlDeleted";
  
      private TemplateAvailability templateAvailability;
  
      @Inject
      public TemplateDefinitionRegistry(TemplateAvailability templateAvailability) {
          this.templateAvailability = templateAvailability;
      }
  
      public TemplateDefinition getTemplateDefinition(String id) throws RegistrationException {
  
          TemplateDefinitionProvider templateDefinitionProvider;
          Map<String, TemplateDefinitionProvider> providers = getProviders();
          synchronized (providers) {
              templateDefinitionProvider = providers.get(id);
          }
          if (templateDefinitionProvider == null) {
              throw new RegistrationException("No TemplateDefinition registered for id: " + id + ", available ids are " + providers.keySet());
          }
          TemplateDefinition templateDefinition = templateDefinitionProvider.getDefinition();
          templateDefinition.setId(id);
          return templateDefinition;
      }
  
      public Collection<TemplateDefinition> getTemplateDefinitions() {
          Collection<TemplateDefinition> templateDefinitions = new ArrayList<TemplateDefinition>();
          Map<String, TemplateDefinitionProvider> providers = getProviders();
          synchronized (providers) {
              for (Map.Entry<String, TemplateDefinitionProvider> entry : providers.entrySet()) {
                  String id = entry.getKey();
                 TemplateDefinitionProvider provider = entry.getValue();
                 try {
                     TemplateDefinition templateDefinition = provider.getDefinition();
                     templateDefinition.setId(id);
                     templateDefinitions.add(templateDefinition);
                 } catch (RegistrationException e) {
                     // one failing provider is no reason to not show any templates
                     log.error("Failed to read template definition from " + provider + ".", e);
                 }
             }
         }
         return templateDefinitions;
     }
 
     public Collection<TemplateDefinition> getAvailableTemplates(Node content) {
 
         try {
             if (content != null && NodeUtil.hasMixin(content, MgnlNodeType.MIX_DELETED)) {
                 return Collections.singleton(get(DELETED_PAGE_TEMPLATE));
             }
         } catch (RepositoryException e) {
             log.error("Failed to check node for deletion status.", e);
         } catch (RegistrationException e) {
             log.error("Deleted content template is not correctly registered.", e);
         }
 
         final ArrayList<TemplateDefinition> availableTemplateDefinitions = new ArrayList<TemplateDefinition>();
         final Collection<TemplateDefinition> templateDefinitions = getTemplateDefinitions();
         for (TemplateDefinition templateDefinition : templateDefinitions) {
             if (isAvailable(templateDefinition, content)) {
                 availableTemplateDefinitions.add(templateDefinition);
             }
         }
         return availableTemplateDefinitions;
     }
 
     protected boolean isAvailable(TemplateDefinition templateDefinition, Node content) {
         if (templateDefinition.getId().equals(DELETED_PAGE_TEMPLATE)) {
             return false;
         }
         // TODO temporary fix for limiting only website to <moduleName>:pages/*
         try {
             if (content.getSession().getWorkspace().getName().equals("website") && !StringUtils.substringAfter(templateDefinition.getId(), ":").startsWith("pages/")) {
                 return false;
             }
         } catch (RepositoryException e) {
         }
         return templateAvailability.isAvailable(content, templateDefinition);
     }
 
     /**
      * Get the Template that could be used for the provided content as a default.
      */
     public TemplateDefinition getDefaultTemplate(Node content) {
 
         // try to use the same as the parent
         TemplateDefinition parentTemplate = null;
         try {
             parentTemplate = getTemplateDefinition(content.getParent());
         } catch (RepositoryException e) {
             log.error("Failed to determine template assigned to parent of node: " + NodeUtil.getNodePathIfPossible(content), e);
         }
 
         if (parentTemplate != null && templateAvailability.isAvailable(content, parentTemplate)) {
             return parentTemplate;
         }
 
         // otherwise use the first available template
         Collection<TemplateDefinition> templates = getAvailableTemplates(content);
         if (templates.isEmpty()) {
             return null;
         }
 
         return templates.iterator().next();
     }
 
     private TemplateDefinition getTemplateDefinition(Node node) throws RepositoryException {
         String templateId = MetaDataUtil.getTemplate(node);
         if (StringUtils.isEmpty(templateId)) {
             return null;
         }
         try {
             // TODO Ioc
             TemplateDefinitionAssignment templateDefinitionAssignment = Components.getComponent(TemplateDefinitionAssignment.class);
             return templateDefinitionAssignment.getAssignedTemplateDefinition(node);
         } catch (RegistrationException e) {
             return null;
         }
     }
 }