/*
 * 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.spark.translation.streaming;

import static org.apache.beam.sdk.metrics.MetricResultsMatchers.attemptedMetricsResult;
import static org.hamcrest.Matchers.hasItem;
import static org.junit.Assert.assertThat;

import java.io.Serializable;
import org.apache.beam.runners.spark.StreamingTest;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.GenerateSequence;
import org.apache.beam.sdk.io.Source;
import org.apache.beam.sdk.metrics.MetricName;
import org.apache.beam.sdk.metrics.MetricNameFilter;
import org.apache.beam.sdk.metrics.MetricQueryResults;
import org.apache.beam.sdk.metrics.MetricsFilter;
import org.apache.beam.sdk.metrics.SourceMetrics;
import org.apache.beam.sdk.testing.TestPipeline;
import org.joda.time.Duration;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;

/**
 * Verify metrics support for {@link Source Sources} in streaming pipelines.
 */
public class StreamingSourceMetricsTest implements Serializable {
  private static final MetricName ELEMENTS_READ = SourceMetrics.elementsRead().getName();

  // Force streaming pipeline using pipeline rule.
  @Rule
  public final transient TestPipeline pipeline = TestPipeline.create();

  @Test
  @Category(StreamingTest.class)
  public void testUnboundedSourceMetrics() {
    final long numElements = 1000;

    pipeline.apply(
        // Use maxReadTime to force unbounded mode.
        GenerateSequence.from(0).to(numElements).withMaxReadTime(Duration.standardDays(1)));

    PipelineResult pipelineResult = pipeline.run();

    MetricQueryResults metrics =
        pipelineResult
            .metrics()
            .queryMetrics(
                MetricsFilter.builder()
                    .addNameFilter(
                        MetricNameFilter.named(ELEMENTS_READ.namespace(), ELEMENTS_READ.name()))
                    .build());

    assertThat(metrics.counters(), hasItem(
        attemptedMetricsResult(
            ELEMENTS_READ.namespace(),
            ELEMENTS_READ.name(),
            "Read(UnboundedCountingSource)",
            1000L)));
  }
}