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.agent.stomp.dto;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.ambari.server.events.AlertDefinitionEventType;
  import org.apache.ambari.server.state.alert.AlertDefinition;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.fasterxml.jackson.annotation.JsonInclude;
  import com.fasterxml.jackson.annotation.JsonProperty;
  
  @JsonInclude(JsonInclude.Include.NON_NULL)
  public class AlertCluster {
  
    private static final Logger LOG = LoggerFactory.getLogger(AlertCluster.class);
  
    private final Map<Long, AlertDefinition> alertDefinitions;
    private final String hostName;
    private Integer staleIntervalMultiplier;
  
    public AlertCluster(AlertDefinition alertDefinition, String hostName, Integer staleIntervalMultiplier) {
      this(Collections.singletonMap(alertDefinition.getDefinitionId(), alertDefinition), hostName, staleIntervalMultiplier);
    }
  
    public AlertCluster(Map<Long, AlertDefinition> alertDefinitions, String hostName, Integer staleIntervalMultiplier) {
      this.alertDefinitions = new HashMap<>(alertDefinitions);
      this.hostName = hostName;
      this.staleIntervalMultiplier = staleIntervalMultiplier;
    }
  
    public AlertCluster(AlertDefinition alertDefinition, String hostName) {
      this(Collections.singletonMap(alertDefinition.getDefinitionId(), alertDefinition), hostName, null);
    }
  
    public AlertCluster(Map<Long, AlertDefinition> alertDefinitions, String hostName) {
      this.alertDefinitions = new HashMap<>(alertDefinitions);
      this.hostName = hostName;
      this.staleIntervalMultiplier = null;
    }
  
    private AlertCluster() {
      alertDefinitions = null;
      hostName = null;
    }
  
    @JsonProperty("staleIntervalMultiplier")
    public Integer getStaleIntervalMultiplier() {
      return staleIntervalMultiplier;
    }
  
    @JsonProperty("alertDefinitions")
    public Collection<AlertDefinition> getAlertDefinitions() {
      return alertDefinitions == null ? Collections.emptyList() : alertDefinitions.values();
    }
  
    @JsonProperty("hostName")
    public String getHostName() {
      return hostName;
    }
  
    public AlertCluster handleUpdate(AlertDefinitionEventType eventType, AlertCluster update) {
      boolean changed = false;
  
      AlertCluster mergedCluster = null;
      Map<Long, AlertDefinition> mergedDefinitions = new HashMap<>();
      Integer mergedStaleIntervalMultiplier = null;
      switch (eventType) {
        case CREATE:
          // FIXME should clear map first?
        case UPDATE:
          for (Map.Entry<Long, AlertDefinition> alertDefinitionEntry : alertDefinitions.entrySet()) {
            Long definitionId = alertDefinitionEntry.getKey();
            if (!update.alertDefinitions.containsKey(definitionId)) {
              mergedDefinitions.put(definitionId, alertDefinitionEntry.getValue());
            } else {
              AlertDefinition newDefinition = update.alertDefinitions.get(definitionId);
              AlertDefinition oldDefinition = alertDefinitionEntry.getValue();
              if (!oldDefinition.deeplyEquals(newDefinition)) {
                changed = true;
              }
              mergedDefinitions.put(definitionId, newDefinition);
            }
          }
          if (addNewAlertDefinitions(update, mergedDefinitions)) {
            changed = true;
          }
          if (update.getStaleIntervalMultiplier() != null
              && !update.getStaleIntervalMultiplier().equals(staleIntervalMultiplier)) {
            mergedStaleIntervalMultiplier = update.getStaleIntervalMultiplier();
            changed = true;
          } else {
            mergedStaleIntervalMultiplier = staleIntervalMultiplier;
          }
          LOG.debug("Handled {} of {} alerts, changed = {}", eventType, update.alertDefinitions.size(), changed);
          break;
        case DELETE:
          for (Map.Entry<Long, AlertDefinition> alertDefinitionEntry : alertDefinitions.entrySet()) {
            Long definitionId = alertDefinitionEntry.getKey();
            if (!update.alertDefinitions.containsKey(definitionId)) {
              mergedDefinitions.put(definitionId, alertDefinitionEntry.getValue());
            } else {
              changed = true;
            }
          }
          mergedStaleIntervalMultiplier = staleIntervalMultiplier;
          LOG.debug("Handled {} of {} alerts", eventType, update.alertDefinitions.size());
          break;
        default:
          LOG.warn("Unhandled event type {}", eventType);
          break;
      }
      if (changed) {
        mergedCluster = new AlertCluster(mergedDefinitions, hostName, mergedStaleIntervalMultiplier);
      }
      return mergedCluster;
    }
  
    /**
     * Add each alert definitions from the update event which are not included in mergedDefinitions
     * @return true if there was such an alert definition
     */
    private boolean addNewAlertDefinitions(AlertCluster update, Map<Long, AlertDefinition> mergedDefinitions) {
      boolean hasNew = false;
      for (Map.Entry<Long, AlertDefinition> each : update.alertDefinitions.entrySet()) {
        if (!mergedDefinitions.containsKey(each.getKey())) {
          mergedDefinitions.put(each.getKey(), each.getValue());
          hasNew = true;
        }
      }
      return hasNew;
    }
  
    public static AlertCluster emptyAlertCluster() {
      return new AlertCluster();
    }
  }
  