/**
    * This file Copyright (c) 2013-2016 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.rest.registry;
  
  import info.magnolia.cms.util.ModuleConfigurationObservingManager;
  import info.magnolia.jcr.node2bean.Node2BeanException;
  import info.magnolia.jcr.predicate.NodeTypePredicate;
  import info.magnolia.jcr.util.NodeTypes;
  import info.magnolia.jcr.util.NodeUtil;
  import info.magnolia.jcr.util.NodeVisitor;
  import info.magnolia.module.ModuleRegistry;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import javax.inject.Inject;
  import javax.inject.Singleton;
  import javax.jcr.Node;
  import javax.jcr.RepositoryException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * ObservingManager for {@link info.magnolia.rest.EndpointDefinition} configured in repository.
   */
  @Singleton
  public class ConfiguredEndpointDefinitionManager extends ModuleConfigurationObservingManager {
  
      public static final String REST_ENDPOINTS_CONFIG_NODE_NAME = "rest-endpoints";
  
      private final Logger log = LoggerFactory.getLogger(getClass());
  
      private Set<String> registeredEndpoints = Collections.synchronizedSet(new HashSet<String>());
      private final EndpointDefinitionRegistry endpointDefinitionRegistry;
  
      @Inject
      public ConfiguredEndpointDefinitionManager(ModuleRegistry moduleRegistry, EndpointDefinitionRegistry endpointDefinitionRegistry) {
          super(REST_ENDPOINTS_CONFIG_NODE_NAME, moduleRegistry);
          this.endpointDefinitionRegistry = endpointDefinitionRegistry;
      }
  
      @Override
      protected void reload(List<Node> nodes) throws RepositoryException {
          final List<EndpointDefinitionProvider> providers = new ArrayList<EndpointDefinitionProvider>();
  
          for (Node node : nodes) {
              NodeUtil.visit(node, new NodeVisitor() {
                  @Override
                  public void visit(Node current) throws RepositoryException {
                      for (Node endpointNode : NodeUtil.getNodes(current, NodeTypes.ContentNode.NAME)) {
                          if (isEndpoint(endpointNode)) {
                              EndpointDefinitionProvider provider = createProvider(endpointNode);
                              if (provider != null) {
                                  providers.add(provider);
                              }
                          }
                      }
                  }
              }, new NodeTypePredicate(NodeTypes.Content.NAME));
          }
  
          this.registeredEndpoints = endpointDefinitionRegistry.unregisterAndRegister(registeredEndpoints, providers);
      }
  
     /**
      * Checks if the endpoint is completely configured.
      */
     private boolean isEndpoint(Node endpointNode) throws RepositoryException {
         return endpointNode.hasProperty(ConfiguredEndpointDefinition.PROPERTY_NAME_IMPLEMENTATION_CLASS);
     }
 
     protected EndpointDefinitionProvider createProvider(Node endpointNode) throws RepositoryException {
         final String name = endpointNode.getName();
 
         try {
             return new ConfiguredEndpointDefinitionProvider(name, endpointNode);
         } catch (Node2BeanException e) {
             log.error("Unable to create provider for endpoint [" + name + "]", e);
         }
 
         return null;
     }
 }