/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ambari.server.controller.internal;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.ambari.server.AmbariException;
import org.apache.ambari.server.controller.AmbariManagementController;
import org.apache.ambari.server.controller.RootServiceRequest;
import org.apache.ambari.server.controller.RootServiceResponse;
import org.apache.ambari.server.controller.spi.NoSuchParentResourceException;
import org.apache.ambari.server.controller.spi.NoSuchResourceException;
import org.apache.ambari.server.controller.spi.Predicate;
import org.apache.ambari.server.controller.spi.Request;
import org.apache.ambari.server.controller.spi.Resource;
import org.apache.ambari.server.controller.spi.SystemException;
import org.apache.ambari.server.controller.spi.UnsupportedPropertyException;
import org.apache.ambari.server.controller.spi.Resource.Type;
import org.apache.ambari.server.controller.utilities.PredicateHelper;
import org.apache.ambari.server.controller.utilities.PropertyHelper;

public class RootServiceResourceProvider extends ReadOnlyResourceProvider {
  
  public static final String SERVICE_NAME_PROPERTY_ID = PropertyHelper
      .getPropertyId("RootService", "service_name");

  private Set<String> pkPropertyIds = new HashSet<String>(
      Arrays.asList(new String[] { SERVICE_NAME_PROPERTY_ID }));

  protected RootServiceResourceProvider(Set<String> propertyIds,
      Map<Type, String> keyPropertyIds,
      AmbariManagementController managementController) {
    super(propertyIds, keyPropertyIds, managementController);
  }
  
  @Override
  public Set<Resource> getResources(Request request, Predicate predicate)
      throws SystemException, UnsupportedPropertyException,
      NoSuchResourceException, NoSuchParentResourceException {

    final RootServiceRequest ambariServiceRequest = getRequest(PredicateHelper
        .getProperties(predicate));
    Set<String> requestedIds = getRequestPropertyIds(request, predicate);

    Set<RootServiceResponse> responses = getResources(new Command<Set<RootServiceResponse>>() {
      @Override
      public Set<RootServiceResponse> invoke() throws AmbariException {
        return getManagementController().getRootServices(
            Collections.singleton(ambariServiceRequest));
      }
    });

    Set<Resource> resources = new HashSet<Resource>();

    for (RootServiceResponse response : responses) {
      Resource resource = new ResourceImpl(Resource.Type.RootService);

      setResourceProperty(resource, SERVICE_NAME_PROPERTY_ID,
          response.getServiceName(), requestedIds);

      resources.add(resource);
    }

    return resources;
  }

  private RootServiceRequest getRequest(Map<String, Object> properties) {
    return new RootServiceRequest((String) properties.get(SERVICE_NAME_PROPERTY_ID));
  }

  @Override
  protected Set<String> getPKPropertyIds() {
    return pkPropertyIds ;
  }

}