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.server.stack.upgrade;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.xml.bind.annotation.XmlAccessType;
  import javax.xml.bind.annotation.XmlAccessorType;
  import javax.xml.bind.annotation.XmlAttribute;
  import javax.xml.bind.annotation.XmlElement;
  import javax.xml.bind.annotation.XmlElementWrapper;
  import javax.xml.bind.annotation.XmlRootElement;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Represents a pack of changes that should be applied to configs
   * when upgrading from a previous stack. In other words, it's a config delta
   * from prev stack.
   *
   * After first call of enumerateConfigChangesByID() method, instance contains
   * a cache of data, so it should not be modified in runtime (otherwise
   * the cache will become outdated).
   */
  @XmlRootElement(name="upgrade-config-changes")
  @XmlAccessorType(XmlAccessType.FIELD)
  public class ConfigUpgradePack {
  
    /**
     * Defines per-service config changes.
     */
    @XmlElementWrapper(name="services")
    @XmlElement(name="service")
    public List<AffectedService> services;
  
    /**
     * Contains a cached mapping of <change id, change definition>.
     */
    private Map<String, ConfigUpgradeChangeDefinition> changesById;
  
    private static final Logger LOG = LoggerFactory.getLogger(ConfigUpgradePack.class);
  
    /**
     * no-arg default constructor for JAXB
     */
    public ConfigUpgradePack() {
    }
  
    public ConfigUpgradePack(List<AffectedService> services) {
      this.services = services;
    }
  
    /**
     * @return a map of <service name, AffectedService>.
     */
    public Map<String, AffectedService> getServiceMap() {
      Map<String, AffectedService> result = new HashMap<>();
      for (AffectedService service : services) {
        result.put(service.name, service);
      }
      return result;
    }
  
    /**
     * @return a map of <change id, change definition>. Map is built once and
     * cached
     */
    public Map<String, ConfigUpgradeChangeDefinition> enumerateConfigChangesByID() {
      if (changesById == null) {
        changesById = new HashMap<>();
        for(AffectedService service : services) {
          for(AffectedComponent component: service.components) {
            for (ConfigUpgradeChangeDefinition changeDefinition : component.changes) {
              if (changeDefinition.id == null) {
                LOG.warn(String.format("Config upgrade change definition for service %s," +
                        " component %s has no id", service.name, component.name));
              } else if (changesById.containsKey(changeDefinition.id)) {
                LOG.warn("Duplicate config upgrade change definition with ID " +
                        changeDefinition.id);
              }
              changesById.put(changeDefinition.id, changeDefinition);
            }
          }
        }
      }
      return changesById;
    }
  
    /**
     * Merges few config upgrade packs into one and returs result. During merge,
     * a deep copy of AffectedService and AffectedComponent lists is added to resulting
     * config upgrade pack. The only level that is not copied deeply is a list of
     * per-component config changes.
     * @param cups list of source config upgrade packs
     * @return merged config upgrade pack that is a deep copy of source
     * config upgrade packs
     */
    public static ConfigUpgradePack merge(ArrayList<ConfigUpgradePack> cups) {
      // Map <service_name, <component_name, component_changes>>
      Map<String, Map<String, AffectedComponent>> mergedServiceMap = new HashMap<>();
  
      for (ConfigUpgradePack configUpgradePack : cups) {
        for (AffectedService service : configUpgradePack.services) {
          if (! mergedServiceMap.containsKey(service.name)) {
            mergedServiceMap.put(service.name, new HashMap<>());
          }
          Map<String, AffectedComponent> mergedComponentMap = mergedServiceMap.get(service.name);
  
          for (AffectedComponent component : service.components) {
            if (! mergedComponentMap.containsKey(component.name)) {
              AffectedComponent mergedComponent = new AffectedComponent();
              mergedComponent.name = component.name;
              mergedComponent.changes = new ArrayList<>();
              mergedComponentMap.put(component.name, mergedComponent);
            }
            AffectedComponent mergedComponent = mergedComponentMap.get(component.name);
            mergedComponent.changes.addAll(component.changes);
          }
  
        }
      }
      // Convert merged maps into new ConfigUpgradePack
      ArrayList<AffectedService> mergedServices = new ArrayList<>();
      for (String serviceName : mergedServiceMap.keySet()) {
        AffectedService mergedService = new AffectedService();
        Map<String, AffectedComponent> mergedComponentMap = mergedServiceMap.get(serviceName);
        mergedService.name = serviceName;
        mergedService.components = new ArrayList<>(mergedComponentMap.values());
        mergedServices.add(mergedService);
      }
  
      return new ConfigUpgradePack(mergedServices);
    }
  
    /**
     * A service definition in the 'services' element.
     */
    public static class AffectedService {
  
      @XmlAttribute
      public String name;
  
      @XmlElement(name="component")
      public List<AffectedComponent> components;
  
      /**
       * @return a map of <component name, AffectedService>
       */
      public Map<String, AffectedComponent> getComponentMap() {
        Map<String, AffectedComponent> result = new HashMap<>();
        for (AffectedComponent component : components) {
          result.put(component.name, component);
        }
        return result;
      }
    }
  
    /**
     * A component definition in the 'services/service' path.
     */
    public static class AffectedComponent {
  
      @XmlAttribute
      public String name;
  
      @XmlElementWrapper(name="changes")
      @XmlElement(name="definition")
      public List<ConfigUpgradeChangeDefinition> changes;
  
    }
  }
  