/*
 * 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.beam.runners.dataflow.worker;

import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.argThat;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import com.google.api.services.dataflow.model.MapTask;
import com.google.api.services.dataflow.model.ParallelInstruction;
import com.google.api.services.dataflow.model.SourceSplitResponse;
import com.google.api.services.dataflow.model.SourceSplitShard;
import com.google.api.services.dataflow.model.WorkItem;
import com.google.api.services.dataflow.model.WorkItemStatus;
import java.io.IOException;
import java.util.ArrayList;
import org.apache.beam.runners.dataflow.options.DataflowWorkerHarnessOptions;
import org.apache.beam.runners.dataflow.util.TimeUtil;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.util.FastNanoClockAndSleeper;
import org.apache.beam.vendor.guava.v20_0.com.google.common.base.Optional;
import org.apache.beam.vendor.guava.v20_0.com.google.common.collect.ImmutableList;
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;
import org.joda.time.Duration;
import org.joda.time.Instant;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.ArgumentCaptor;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

/** Unit tests for {@link BatchDataflowWorker}. */
@RunWith(JUnit4.class)
public class BatchDataflowWorkerTest {

  private static class WorkerException extends Exception {}

  @Rule public FastNanoClockAndSleeper clockAndSleeper = new FastNanoClockAndSleeper();

  @Mock WorkUnitClient mockWorkUnitClient;

  @Mock DataflowWorkProgressUpdater mockProgressUpdater;

  @Mock DataflowWorkExecutor mockWorkExecutor;

  DataflowWorkerHarnessOptions options;

  @Before
  public void setUp() {
    MockitoAnnotations.initMocks(this);
    options = PipelineOptionsFactory.as(DataflowWorkerHarnessOptions.class);
  }

  @Test
  public void testWhenNoWorkIsReturnedThatWeImmediatelyRetry() throws Exception {
    final String workItemId = "14";
    BatchDataflowWorker worker =
        new BatchDataflowWorker(
            null /* pipeline */,
            SdkHarnessRegistries.emptySdkHarnessRegistry(),
            mockWorkUnitClient,
            IntrinsicMapTaskExecutorFactory.defaultFactory(),
            options);

    WorkItem workItem = new WorkItem();
    workItem.setId(Long.parseLong(workItemId));
    workItem.setJobId("SuccessfulEmptyMapTask");
    workItem.setInitialReportIndex(12L);
    workItem.setMapTask(
        new MapTask()
            .setInstructions(new ArrayList<ParallelInstruction>())
            .setStageName("testStage"));
    workItem.setLeaseExpireTime(TimeUtil.toCloudTime(Instant.now()));
    workItem.setReportStatusInterval(TimeUtil.toCloudDuration(Duration.standardMinutes(1)));

    when(mockWorkUnitClient.getWorkItem())
        .thenReturn(Optional.<WorkItem>absent())
        .thenReturn(Optional.of(workItem));

    assertTrue(worker.getAndPerformWork());
    verify(mockWorkUnitClient)
        .reportWorkItemStatus(
            argThat(
                new TypeSafeMatcher<WorkItemStatus>() {
                  @Override
                  public void describeTo(Description description) {}

                  @Override
                  protected boolean matchesSafely(WorkItemStatus item) {
                    assertTrue(item.getCompleted());
                    assertEquals(workItemId, item.getWorkItemId());
                    return true;
                  }
                }));
  }

  @Test
  public void testWhenProcessingWorkUnitFailsWeReportStatus() throws Exception {
    BatchDataflowWorker worker =
        new BatchDataflowWorker(
            null /* pipeline */,
            SdkHarnessRegistries.emptySdkHarnessRegistry(),
            mockWorkUnitClient,
            IntrinsicMapTaskExecutorFactory.defaultFactory(),
            options);
    // In practice this value is always 1, but for the sake of testing send a different value.
    long initialReportIndex = 4L;
    WorkItem workItem =
        new WorkItem()
            .setId(1L)
            .setJobId("Expected to fail the job")
            .setInitialReportIndex(initialReportIndex);
    WorkItemStatusClient workItemStatusClient = mock(WorkItemStatusClient.class);

    worker.doWork(workItem, workItemStatusClient);
    ArgumentCaptor<Throwable> errorCaptor = ArgumentCaptor.forClass(Throwable.class);
    verify(workItemStatusClient).reportError(errorCaptor.capture());

    Throwable error = errorCaptor.getValue();
    assertThat(error, notNullValue());
    assertThat(error.getMessage(), equalTo("Unknown kind of work item: " + workItem.toString()));
  }

  @Test
  public void testStartAndStopProgressReport() throws Exception {
    BatchDataflowWorker worker =
        new BatchDataflowWorker(
            null /* pipeline */,
            SdkHarnessRegistries.emptySdkHarnessRegistry(),
            mockWorkUnitClient,
            IntrinsicMapTaskExecutorFactory.defaultFactory(),
            options);
    worker.executeWork(mockWorkExecutor, mockProgressUpdater);
    verify(mockProgressUpdater, times(1)).startReportingProgress();
    verify(mockProgressUpdater, times(1)).stopReportingProgress();
  }

  @Test
  public void testStopProgressReportInCaseOfFailure() throws Exception {
    doThrow(new WorkerException()).when(mockWorkExecutor).execute();
    BatchDataflowWorker worker =
        new BatchDataflowWorker(
            null /* pipeline */,
            SdkHarnessRegistries.emptySdkHarnessRegistry(),
            mockWorkUnitClient,
            IntrinsicMapTaskExecutorFactory.defaultFactory(),
            options);
    try {
      worker.executeWork(mockWorkExecutor, mockProgressUpdater);
    } catch (WorkerException e) {
      /* Expected - ignore. */
    }
    verify(mockProgressUpdater, times(1)).stopReportingProgress();
  }

  @Test
  public void testIsSplitResponseTooLarge() throws IOException {
    SourceSplitResponse splitResponse = new SourceSplitResponse();
    splitResponse.setShards(
        ImmutableList.<SourceSplitShard>of(new SourceSplitShard(), new SourceSplitShard()));
    assertThat(DataflowApiUtils.computeSerializedSizeBytes(splitResponse), greaterThan(0L));
  }
}
