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.kafka.connect.runtime;
  
  import org.apache.kafka.connect.connector.Connector;
  import org.apache.kafka.connect.connector.Task;
  import org.apache.kafka.connect.runtime.rest.entities.ConnectorStateInfo;
  import org.apache.kafka.connect.util.ConnectorTaskId;
  
  import java.util.Collection;
  import java.util.Objects;
  
  /**
   * An immutable restart plan per connector.
   */
  public class RestartPlan {
  
      private final RestartRequest request;
      private final ConnectorStateInfo stateInfo;
      private final Collection<ConnectorTaskId> idsToRestart;
  
      /**
       * Create a new plan to restart a connector and optionally its tasks.
       *
       * @param request          the restart request; may not be null
       * @param restartStateInfo the current state info for the connector; may not be null
       */
      public RestartPlan(RestartRequest request, ConnectorStateInfo restartStateInfo) {
          this.request = Objects.requireNonNull(request, "RestartRequest name may not be null");
          this.stateInfo = Objects.requireNonNull(restartStateInfo, "ConnectorStateInfo name may not be null");
          // Collect the task IDs to stop and restart (may be none)
          this.idsToRestart = stateInfo.tasks()
                  .stream()
                  .filter(this::isRestarting)
                  .map(taskState -> new ConnectorTaskId(request.connectorName(), taskState.id())).toList();
      }
  
      /**
       * Get the connector name.
       *
       * @return the name of the connector; never null
       */
      public String connectorName() {
          return request.connectorName();
      }
  
      /**
       * Get the original {@link RestartRequest}.
       *
       * @return the restart request; never null
       */
      public RestartRequest restartRequest() {
          return request;
      }
  
      /**
       * Get the {@link ConnectorStateInfo} that reflects the current state of the connector <em>except</em> with the {@code status}
       * set to {@link AbstractStatus.State#RESTARTING} for the {@link Connector} instance and any {@link Task} instances that
       * are to be restarted, based upon the {@link #restartRequest() restart request}.
       *
       * @return the connector state info that reflects the restart plan; never null
       */
      public ConnectorStateInfo restartConnectorStateInfo() {
          return stateInfo;
      }
  
      /**
       * Get the immutable collection of {@link ConnectorTaskId} for all tasks to be restarted
       * based upon the {@link #restartRequest() restart request}.
       *
       * @return the IDs of the tasks to be restarted; never null but possibly empty
       */
      public Collection<ConnectorTaskId> taskIdsToRestart() {
          return idsToRestart;
      }
  
      /**
       * Determine whether the {@link Connector} instance is to be restarted
       * based upon the {@link #restartRequest() restart request}.
       *
       * @return true if the {@link Connector} instance is to be restarted, or false otherwise
       */
      public boolean shouldRestartConnector() {
          return isRestarting(stateInfo.connector());
      }
  
      /**
       * Determine whether at least one {@link Task} instance is to be restarted
       * based upon the {@link #restartRequest() restart request}.
       *
       * @return true if any {@link Task} instances are to be restarted, or false if none are to be restarted
       */
      public boolean shouldRestartTasks() {
          return !taskIdsToRestart().isEmpty();
      }
  
      /**
       * Get the number of connector tasks that are to be restarted
       * based upon the {@link #restartRequest() restart request}.
       *
       * @return the number of {@link Task} instance is to be restarted
       */
      public int restartTaskCount() {
          return taskIdsToRestart().size();
      }
  
      /**
       * Get the total number of tasks in the connector.
       *
       * @return the total number of tasks
       */
      public int totalTaskCount() {
          return stateInfo.tasks().size();
      }
  
      private boolean isRestarting(ConnectorStateInfo.AbstractState state) {
          return isRestarting(state.state());
      }
  
      private boolean isRestarting(String state) {
          return AbstractStatus.State.RESTARTING.toString().equalsIgnoreCase(state);
      }
  
      @Override
      public String toString() {
          return shouldRestartConnector()
                  ? String.format("plan to restart connector and %d of %d tasks for %s", restartTaskCount(), totalTaskCount(), request)
                  : String.format("plan to restart %d of %d tasks for %s", restartTaskCount(), totalTaskCount(), request);
      }
  }
  