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.streams.processor.internals;
  
  import org.apache.kafka.clients.consumer.OffsetAndMetadata;
  import org.apache.kafka.common.TopicPartition;
  import org.apache.kafka.common.utils.Time;
  import org.apache.kafka.streams.processor.TaskId;
  
  import org.junit.jupiter.api.Test;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import java.util.Set;
  import java.util.function.Consumer;
  
  import static org.apache.kafka.test.StreamsTestUtils.TaskBuilder.standbyTask;
  import static org.apache.kafka.test.StreamsTestUtils.TaskBuilder.statefulTask;
  import static org.apache.kafka.test.StreamsTestUtils.TaskBuilder.statelessTask;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.mockito.Mockito.verify;
  
  class ReadOnlyTaskTest {
  
      private final List<String> readOnlyMethods = List.of(
          "needsInitializationOrRestoration",
          "inputPartitions",
          "changelogPartitions",
          "commitRequested",
          "commitNeeded",
          "isActive",
          "changelogOffsets",
          "state",
          "id",
          "store"
      );
  
      private final List<String> objectMethods = List.of(
          "wait",
          "equals",
          "getClass",
          "hashCode",
          "notify",
          "notifyAll",
          "toString"
      );
  
      final Task task = statelessTask(new TaskId(1, 0)).build();
  
      @Test
      public void shouldDelegateNeedsInitializationOrRestoration() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.needsInitializationOrRestoration();
  
          verify(task).needsInitializationOrRestoration();
      }
  
      @Test
      public void shouldDelegateId() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.id();
  
          verify(task).id();
      }
  
      @Test
      public void shouldDelegateIsActive() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.isActive();
  
          verify(task).isActive();
      }
  
      @Test
      public void shouldDelegateInputPartitions() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.inputPartitions();
  
          verify(task).inputPartitions();
      }
  
      @Test
      public void shouldDelegateChangelogPartitions() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.changelogPartitions();
  
          verify(task).changelogPartitions();
      }
  
      @Test
      public void shouldDelegateCommitRequested() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.commitRequested();
  
          verify(task).commitRequested();
      }
  
      @Test
      public void shouldDelegateState() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
  
          readOnlyTask.state();
  
          verify(task).state();
      }
  
      @Test
      public void shouldDelegateCommitNeededIfStandby() {
          final StandbyTask standbyTask =
              standbyTask(new TaskId(1, 0), Set.of(new TopicPartition("topic", 0))).build();
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(standbyTask);
  
          readOnlyTask.commitNeeded();
  
          verify(standbyTask).commitNeeded();
      }
  
      @Test
      public void shouldThrowUnsupportedOperationExceptionForCommitNeededIfActive() {
          final StreamTask statefulTask =
              statefulTask(new TaskId(1, 0), Set.of(new TopicPartition("topic", 0))).build();
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(statefulTask);
  
          final Exception exception = assertThrows(UnsupportedOperationException.class, readOnlyTask::commitNeeded);
  
          assertEquals("This task is read-only", exception.getMessage());
      }
  
      @Test
      public void shouldThrowUnsupportedOperationExceptionForForbiddenMethods() {
          final ReadOnlyTask readOnlyTask = new ReadOnlyTask(task);
          for (final Method method : ReadOnlyTask.class.getMethods()) {
              final String methodName = method.getName();
              if (!readOnlyMethods.contains(methodName) && !objectMethods.contains(methodName)) {
                  shouldThrowUnsupportedOperationException(readOnlyTask, method);
              }
          }
  
      }
  
      private void shouldThrowUnsupportedOperationException(final ReadOnlyTask readOnlyTask,
                                                            final Method method) {
          final Exception exception = assertThrows(
              UnsupportedOperationException.class,
              () -> {
                  try {
                      method.invoke(readOnlyTask, getParameters(method.getParameterTypes()));
                  } catch (final InvocationTargetException invocationTargetException) {
                      throw invocationTargetException.getCause();
                  }
              },
              "Something unexpected happened during invocation of method '" + method.getName() + "'!"
          );
          assertEquals("This task is read-only", exception.getMessage());
      }
  
      private Object[] getParameters(final Class<?>[] parameterTypes) throws Exception {
          final Object[] parameters = new Object[parameterTypes.length];
  
          for (int i = 0; i < parameterTypes.length; ++i) {
              switch (parameterTypes[i].getName()) {
                  case "boolean":
                      parameters[i] = true;
                      break;
                  case "long":
                      parameters[i] = 0;
                      break;
                  case "java.util.Set":
                      parameters[i] = Collections.emptySet();
                      break;
                  case "java.util.Collection":
                      parameters[i] = Collections.emptySet();
                      break;
                  case "java.util.Map":
                      parameters[i] = Collections.emptyMap();
                      break;
                  case "org.apache.kafka.common.TopicPartition":
                      parameters[i] = new TopicPartition("topic", 0);
                      break;
                  case "org.apache.kafka.clients.consumer.OffsetAndMetadata":
                      parameters[i] = new OffsetAndMetadata(0, Optional.empty(), "");
                      break;
                  case "java.lang.Exception":
                      parameters[i] = new IllegalStateException();
                      break;
                  case "java.util.function.Consumer":
                      parameters[i] = (Consumer) ignored -> { };
                      break;
                  case "java.lang.Iterable":
                      parameters[i] = Collections.emptySet();
                      break;
                  case "org.apache.kafka.common.utils.Time":
                      parameters[i] = Time.SYSTEM;
                      break;
                  default:
                      parameters[i] = parameterTypes[i].getConstructor().newInstance();
              }
          }
  
          return parameters;
      }
  }