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.common.requests;
  
  import org.apache.kafka.common.Node;
  import org.apache.kafka.common.errors.InvalidRequestException;
  import org.apache.kafka.common.errors.UnsupportedVersionException;
  import org.apache.kafka.common.message.FindCoordinatorRequestData;
  import org.apache.kafka.common.message.FindCoordinatorResponseData;
  import org.apache.kafka.common.protocol.ApiKeys;
  import org.apache.kafka.common.protocol.Errors;
  import org.apache.kafka.common.protocol.Readable;
  
  import java.util.Collections;
  
  public class FindCoordinatorRequest extends AbstractRequest {
  
      public static final short MIN_BATCHED_VERSION = 4;
  
      public static class Builder extends AbstractRequest.Builder<FindCoordinatorRequest> {
          private final FindCoordinatorRequestData data;
  
          public Builder(FindCoordinatorRequestData data) {
              super(ApiKeys.FIND_COORDINATOR);
              this.data = data;
          }
  
          @Override
          public FindCoordinatorRequest build(short version) {
              if (version < 1 && data.keyType() == CoordinatorType.TRANSACTION.id()) {
                  throw new UnsupportedVersionException("Cannot create a v" + version + " FindCoordinator request " +
                          "because we require features supported only in 2 or later.");
              }
              int batchedKeys = data.coordinatorKeys().size();
              if (version < MIN_BATCHED_VERSION) {
                  if (batchedKeys > 1)
                      throw new NoBatchedFindCoordinatorsException("Cannot create a v" + version + " FindCoordinator request " +
                          "because we require features supported only in " + MIN_BATCHED_VERSION + " or later.");
                  if (batchedKeys == 1) {
                      data.setKey(data.coordinatorKeys().get(0));
                      data.setCoordinatorKeys(Collections.emptyList());
                  }
              } else if (batchedKeys == 0 && data.key() != null) {
                  data.setCoordinatorKeys(Collections.singletonList(data.key()));
                  data.setKey(""); // default value
              }
              return new FindCoordinatorRequest(data, version);
          }
  
          @Override
          public String toString() {
              return data.toString();
          }
  
          public FindCoordinatorRequestData data() {
              return data;
          }
      }
  
      /**
       * Indicates that it is not possible to lookup coordinators in batches with FindCoordinator. Instead
       * coordinators must be looked up one by one.
       */
      public static class NoBatchedFindCoordinatorsException extends UnsupportedVersionException {
          private static final long serialVersionUID = 1L;
  
          public NoBatchedFindCoordinatorsException(String message) {
              super(message);
          }
      }
  
      private final FindCoordinatorRequestData data;
  
      private FindCoordinatorRequest(FindCoordinatorRequestData data, short version) {
          super(ApiKeys.FIND_COORDINATOR, version);
          this.data = data;
      }
  
      @Override
      public AbstractResponse getErrorResponse(int throttleTimeMs, Throwable e) {
          FindCoordinatorResponseData response = new FindCoordinatorResponseData();
          if (version() >= 2) {
              response.setThrottleTimeMs(throttleTimeMs);
          }
          Errors error = Errors.forException(e);
          if (version() < MIN_BATCHED_VERSION) {
              return FindCoordinatorResponse.prepareOldResponse(error, Node.noNode());
          } else {
              return FindCoordinatorResponse.prepareErrorResponse(error, data.coordinatorKeys());
          }
      }
  
      public static FindCoordinatorRequest parse(Readable readable, short version) {
          return new FindCoordinatorRequest(new FindCoordinatorRequestData(readable, version),
              version);
      }
  
      @Override
      public FindCoordinatorRequestData data() {
          return data;
      }
  
      public enum CoordinatorType {
          GROUP((byte) 0), TRANSACTION((byte) 1), SHARE((byte) 2);
  
          final byte id;
  
          CoordinatorType(byte id) {
              this.id = id;
          }
  
          public byte id() {
              return id;
          }
  
          public static CoordinatorType forId(byte id) {
              switch (id) {
                  case 0:
                      return GROUP;
                  case 1:
                      return TRANSACTION;
                  case 2:
                      return SHARE;
                  default:
                      throw new InvalidRequestException("Unknown coordinator type received: " + id);
              }
          }
      }
  
  }
  