/*
 * 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.sdk.nexmark.queries;

import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.junit.Assert.assertThat;

import java.util.Random;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.FileSystems;
import org.apache.beam.sdk.io.fs.ResourceId;
import org.apache.beam.sdk.nexmark.NexmarkConfiguration;
import org.apache.beam.sdk.nexmark.NexmarkUtils;
import org.apache.beam.sdk.nexmark.model.Bid;
import org.apache.beam.sdk.nexmark.model.Event;
import org.apache.beam.sdk.nexmark.model.KnownSize;
import org.apache.beam.sdk.testing.NeedsRunner;
import org.apache.beam.sdk.testing.PAssert;
import org.apache.beam.sdk.testing.TestPipeline;
import org.apache.beam.sdk.transforms.Count;
import org.apache.beam.sdk.transforms.Flatten;
import org.apache.beam.sdk.transforms.windowing.GlobalWindows;
import org.apache.beam.sdk.transforms.windowing.Window;
import org.apache.beam.sdk.values.KV;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.PCollectionList;
import org.apache.beam.sdk.values.TimestampedValue;
import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.Iterables;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Test the various NEXMark queries yield results coherent with their models. */
@RunWith(JUnit4.class)
public class SessionSideInputJoinTest {

  @Rule public TestPipeline p = TestPipeline.create();

  @Before
  public void setupPipeline() {
    NexmarkUtils.setupPipeline(NexmarkUtils.CoderStrategy.HAND, p);
  }

  /** Test {@code query} matches {@code model}. */
  private <T extends KnownSize> void queryMatchesModel(
      String name,
      NexmarkConfiguration config,
      NexmarkQueryTransform<T> query,
      NexmarkQueryModel<T> model,
      boolean streamingMode)
      throws Exception {

    ResourceId sideInputResourceId =
        FileSystems.matchNewResource(
            String.format(
                "%s/SessionSideInputJoin-%s",
                p.getOptions().getTempLocation(), new Random().nextInt()),
            false);
    config.sideInputUrl = sideInputResourceId.toString();

    try {
      PCollection<KV<Long, String>> sideInput = NexmarkUtils.prepareSideInput(p, config);
      query.setSideInput(sideInput);

      PCollection<Event> events =
          p.apply(
              name + ".Read",
              streamingMode
                  ? NexmarkUtils.streamEventsSource(config)
                  : NexmarkUtils.batchEventsSource(config));

      PCollection<TimestampedValue<T>> results =
          (PCollection<TimestampedValue<T>>) events.apply(new NexmarkQuery<>(config, query));
      PAssert.that(results).satisfies(model.assertionFor());
      PipelineResult result = p.run();
      result.waitUntilFinish();
    } finally {
      NexmarkUtils.cleanUpSideInput(config);
    }
  }

  /**
   * A smoke test that the count of input bids and outputs are the same, to help diagnose flakiness
   * in more complex tests.
   */
  @Test
  @Category(NeedsRunner.class)
  public void inputOutputSameEvents() throws Exception {
    NexmarkConfiguration config = NexmarkConfiguration.DEFAULT.copy();
    config.sideInputType = NexmarkUtils.SideInputType.DIRECT;
    config.numEventGenerators = 1;
    config.numEvents = 5000;
    config.sideInputRowCount = 10;
    config.sideInputNumShards = 3;
    PCollection<KV<Long, String>> sideInput = NexmarkUtils.prepareSideInput(p, config);

    try {
      PCollection<Event> input = p.apply(NexmarkUtils.batchEventsSource(config));
      PCollection<Bid> justBids = input.apply(NexmarkQueryUtil.JUST_BIDS);
      PCollection<Long> bidCount = justBids.apply("Count Bids", Count.globally());

      NexmarkQueryTransform<Bid> query = new SessionSideInputJoin(config);
      query.setSideInput(sideInput);

      PCollection<TimestampedValue<Bid>> output =
          (PCollection<TimestampedValue<Bid>>) input.apply(new NexmarkQuery(config, query));
      PCollection<Long> outputCount =
          output.apply(Window.into(new GlobalWindows())).apply("Count outputs", Count.globally());

      PAssert.that(PCollectionList.of(bidCount).and(outputCount).apply(Flatten.pCollections()))
          .satisfies(
              counts -> {
                assertThat(Iterables.size(counts), equalTo(2));
                assertThat(Iterables.get(counts, 0), greaterThan(0L));
                assertThat(Iterables.get(counts, 0), equalTo(Iterables.get(counts, 1)));
                return null;
              });
      p.run();
    } finally {
      NexmarkUtils.cleanUpSideInput(config);
    }
  }

  @Test
  @Category(NeedsRunner.class)
  public void queryMatchesModelBatchDirect() throws Exception {
    NexmarkConfiguration config = NexmarkConfiguration.DEFAULT.copy();
    config.sideInputType = NexmarkUtils.SideInputType.DIRECT;
    config.numEventGenerators = 1;
    config.numEvents = 5000;
    config.sideInputRowCount = 10;
    config.sideInputNumShards = 3;

    queryMatchesModel(
        "SessionSideInputJoinTestBatch",
        config,
        new SessionSideInputJoin(config),
        new SessionSideInputJoinModel(config),
        false);
  }

  @Test
  @Category(NeedsRunner.class)
  public void queryMatchesModelStreamingDirect() throws Exception {
    NexmarkConfiguration config = NexmarkConfiguration.DEFAULT.copy();
    config.sideInputType = NexmarkUtils.SideInputType.DIRECT;
    config.numEventGenerators = 1;
    config.numEvents = 5000;
    config.sideInputRowCount = 10;
    config.sideInputNumShards = 3;
    queryMatchesModel(
        "SessionSideInputJoinTestStreaming",
        config,
        new SessionSideInputJoin(config),
        new SessionSideInputJoinModel(config),
        true);
  }

  @Test
  @Category(NeedsRunner.class)
  public void queryMatchesModelBatchCsv() throws Exception {
    NexmarkConfiguration config = NexmarkConfiguration.DEFAULT.copy();
    config.sideInputType = NexmarkUtils.SideInputType.CSV;
    config.numEventGenerators = 1;
    config.numEvents = 5000;
    config.sideInputRowCount = 10;
    config.sideInputNumShards = 3;

    queryMatchesModel(
        "SessionSideInputJoinTestBatch",
        config,
        new SessionSideInputJoin(config),
        new SessionSideInputJoinModel(config),
        false);
  }

  @Test
  @Category(NeedsRunner.class)
  public void queryMatchesModelStreamingCsv() throws Exception {
    NexmarkConfiguration config = NexmarkConfiguration.DEFAULT.copy();
    config.sideInputType = NexmarkUtils.SideInputType.CSV;
    config.numEventGenerators = 1;
    config.numEvents = 5000;
    config.sideInputRowCount = 10;
    config.sideInputNumShards = 3;
    queryMatchesModel(
        "SessionSideInputJoinTestStreaming",
        config,
        new SessionSideInputJoin(config),
        new SessionSideInputJoinModel(config),
        true);
  }
}
