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.image;
  
  import org.apache.kafka.common.Uuid;
  import org.apache.kafka.common.metadata.FeatureLevelRecord;
  import org.apache.kafka.common.metadata.PartitionRecord;
  import org.apache.kafka.common.metadata.RegisterBrokerRecord;
  import org.apache.kafka.common.metadata.TopicRecord;
  import org.apache.kafka.image.writer.ImageWriterOptions;
  import org.apache.kafka.image.writer.RecordListWriter;
  import org.apache.kafka.image.writer.UnwritableMetadataException;
  import org.apache.kafka.metadata.RecordTestUtils;
  import org.apache.kafka.server.common.ApiMessageAndVersion;
  import org.apache.kafka.server.common.MetadataVersion;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Consumer;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  
  @Timeout(value = 40)
  public class ImageDowngradeTest {
      static class MockLossConsumer implements Consumer<UnwritableMetadataException> {
          private final MetadataVersion expectedMetadataVersion;
          private final List<String> losses;
  
          MockLossConsumer(MetadataVersion expectedMetadataVersion) {
              this.expectedMetadataVersion = expectedMetadataVersion;
              this.losses = new ArrayList<>();
          }
  
          @Override
          public void accept(UnwritableMetadataException e) {
              assertEquals(expectedMetadataVersion, e.metadataVersion());
              losses.add(e.loss());
          }
      }
  
      static final List<ApiMessageAndVersion> TEST_RECORDS = List.of(
              new ApiMessageAndVersion(new TopicRecord().
                      setName("foo").
                      setTopicId(Uuid.fromString("5JPuABiJTPu2pQjpZWM6_A")), (short) 0),
              new ApiMessageAndVersion(new PartitionRecord().
                      setTopicId(Uuid.fromString("5JPuABiJTPu2pQjpZWM6_A")).
                      setReplicas(List.of(0, 1)).
                      setIsr(List.of(0, 1)).
                      setLeader(0).
                      setLeaderEpoch(1).
                      setPartitionEpoch(2), (short) 0));
  
      static ApiMessageAndVersion metadataVersionRecord(MetadataVersion metadataVersion) {
          return new ApiMessageAndVersion(new FeatureLevelRecord().
                  setName(MetadataVersion.FEATURE_NAME).
                  setFeatureLevel(metadataVersion.featureLevel()), (short) 0);
      }
  
      /**
       * Test downgrading to a MetadataVersion that doesn't support ZK migration.
       */
      @Test
      public void testPreZkMigrationSupportVersion() {
          writeWithExpectedLosses(MetadataVersion.IBP_3_3_IV3,
              List.of(
                  "the isMigratingZkBroker state of one or more brokers"),
              List.of(
                  metadataVersionRecord(MetadataVersion.IBP_3_4_IV0),
                  new ApiMessageAndVersion(new RegisterBrokerRecord().
                      setBrokerId(123).
                      setIncarnationId(Uuid.fromString("XgjKo16hRWeWrTui0iR5Nw")).
                      setBrokerEpoch(456).
                      setRack(null).
                      setFenced(false).
                      setInControlledShutdown(true).
                      setIsMigratingZkBroker(true), (short) 2),
                  TEST_RECORDS.get(0),
                  TEST_RECORDS.get(1)),
              List.of(
                  metadataVersionRecord(MetadataVersion.IBP_3_3_IV3),
                  new ApiMessageAndVersion(new RegisterBrokerRecord().
                      setBrokerId(123).
                      setIncarnationId(Uuid.fromString("XgjKo16hRWeWrTui0iR5Nw")).
                      setBrokerEpoch(456).
                      setRack(null).
                      setFenced(false).
                      setInControlledShutdown(true), (short) 1),
                  TEST_RECORDS.get(0),
                  TEST_RECORDS.get(1))
          );
      }
  
      @Test
      void testDirectoryAssignmentState() {
          MetadataVersion outputMetadataVersion = MetadataVersion.IBP_3_7_IV0;
          MetadataVersion inputMetadataVersion = outputMetadataVersion;
          PartitionRecord testPartitionRecord = (PartitionRecord) TEST_RECORDS.get(1).message();
          writeWithExpectedLosses(outputMetadataVersion,
              List.of(
                      "the directory assignment state of one or more replicas"),
              List.of(
                  metadataVersionRecord(inputMetadataVersion),
                  TEST_RECORDS.get(0),
                  new ApiMessageAndVersion(
                      testPartitionRecord.duplicate().setDirectories(List.of(
                          Uuid.fromString("c7QfSi6xSIGQVh3Qd5RJxA"),
                          Uuid.fromString("rWaCHejCRRiptDMvW5Xw0g"))),
                      (short) 2)),
              List.of(
                  metadataVersionRecord(outputMetadataVersion),
                  TEST_RECORDS.get(0),
                  new ApiMessageAndVersion(
                      testPartitionRecord.duplicate().setDirectories(List.of()),
                      (short) 0))
          );
      }
  
      private static void writeWithExpectedLosses(
          MetadataVersion metadataVersion,
          List<String> expectedLosses,
          List<ApiMessageAndVersion> inputs,
          List<ApiMessageAndVersion> expectedOutputs
      ) {
          MockLossConsumer lossConsumer = new MockLossConsumer(metadataVersion);
          MetadataDelta delta = new MetadataDelta.Builder().build();
          RecordTestUtils.replayAll(delta, inputs);
          MetadataImage image = delta.apply(MetadataProvenance.EMPTY);
          RecordListWriter writer = new RecordListWriter();
          image.write(writer, new ImageWriterOptions.Builder(metadataVersion).
                  setLossHandler(lossConsumer).
                  build());
          assertEquals(expectedLosses, lossConsumer.losses, "Failed to get expected metadata losses.");
          assertEquals(expectedOutputs, writer.records(), "Failed to get expected output records.");
      }
  }
  