content: /**
   * 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.spi;
  
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * The {@link ClusterInformation} class is used to pass the state of the cluster
   * as simple primitive values and collections. It contains the following types of information:
   * <ul>
   * <li>The name of a cluster
   * <li>The current desired configurations of a cluster
   * <li>The hosts where services and components are installed
   * <li>The security state of the cluster
   * </ul>
   */
  public class ClusterInformation {
  
    /**
     * The cluster's current configurations.
     */
    private final Map<String, Map<String, String>> m_configurations;
  
    /**
     * The name of the cluster.
     */
    private final String m_clusterName;
  
    /**
     * {@code true} if the cluster is kerberized.
     */
    private final boolean m_isKerberosEnabled;
  
    /**
     * A simple representation of the cluster topology where the key is the
     * combination of service/component and the value is the set of hosts.
     */
    private final Map<String, Set<String>> m_topology;
  
    /**
     * The current version of every service in the cluster.
     */
    private final Map<String, RepositoryVersion> m_serviceVersions;
  
    /**
     * Constructor.
     *
     * @param clusterName
     *          the name of the cluster.
     * @param isKerberosEnabled
     *          {@code true} if the cluster is Kerberized.
     * @param configurations
     *          a mapping of configuration type (such as foo-site) to the specific
     *          configurations (such as http.port : 8080).
     * @param topology
     *          a mapping of the cluster topology where the key is a combination
     *          of service / component and the value is the hosts where it is
     *          installed.
     * @param serviceVersions
     *          the current repository version for every service in the cluster.
     */
    public ClusterInformation(String clusterName, boolean isKerberosEnabled,
        Map<String, Map<String, String>> configurations, Map<String, Set<String>> topology,
        Map<String, RepositoryVersion> serviceVersions) {
      m_configurations = configurations;
      m_clusterName = clusterName;
      m_isKerberosEnabled = isKerberosEnabled;
      m_topology = topology;
      m_serviceVersions = serviceVersions;
    }
  
    /**
     * Gets the cluster name.
     *
     * @return the cluster name.
     */
    public String getClusterName() {
      return m_clusterName;
    }
  
    /**
     * Gets whether the cluster is Kerberized.
     *
     * @return {@code true} if the cluster is Kerberized.
     */
    public boolean isKerberosEnabled() {
      return m_isKerberosEnabled;
    }
  
    /**
     * Gets any hosts where the matching service and component are installed.
     *
     * @param serviceName
     *          the service name
     * @param componentName
     *          the component name
     * @return the set of hosts where the component is installed, or an empty set.
     */
    public Set<String> getHosts(String serviceName, String componentName) {
      Set<String> hosts = m_topology.get(serviceName + "/" + componentName);
      if (null == hosts) {
        hosts = new HashSet<>();
      }
  
      return hosts;
    }
  
    /**
     * Gets the configuration properties for the specified type. If the type does
     * not exist, this will return {@code null}.
     *
     * @param configurationType
     *          the configuration type to retrieve.
     * @return the property name and value pairs for the configuration type, or
     *         {@code null} if no configuration type exists.
     */
    public Map<String, String> getConfigurationProperties(String configurationType) {
      return m_configurations.get(configurationType);
    }
  
    /**
     * Gets a configuration value given the type and property name.
     *
     * @param configurationType
     *          the configuration type, such as foo-site.
     * @param propertyName
     *          the property name, such as http.port
     * @return the property value, or {@code null} if it does not exist.
     */
    public String getConfigurationProperty(String configurationType, String propertyName) {
      Map<String, String> configType = getConfigurationProperties(configurationType);
      if (null == configType) {
        return null;
      }
  
      return configType.get(propertyName);
    }
  
    /**
     * Gets the {@link RepositoryVersion} for the given service which represents
     * the service's current version in the cluster.
     *
     * @param serviceName
     *          the service name.
     * @return the repository version information for the given service.
     */
    public RepositoryVersion getServiceRepositoryVersion(String serviceName) {
      return m_serviceVersions.get(serviceName);
    }
  
    /**
     * Gets the services installed in the cluster.
     *
     * @return the services in the cluster.
     */
    public Set<String> getServices() {
      return m_serviceVersions.keySet();
    }
  }
  