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.beam.sdk.transforms.windowing;
  
  import static org.apache.beam.sdk.testing.WindowFnTestUtils.runWindowFn;
  import static org.apache.beam.sdk.testing.WindowFnTestUtils.set;
  import static org.apache.beam.sdk.transforms.display.DisplayDataMatchers.hasDisplayItem;
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.allOf;
  import static org.hamcrest.Matchers.containsString;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import org.apache.beam.sdk.testing.WindowFnTestUtils;
  import org.apache.beam.sdk.transforms.display.DisplayData;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.joda.time.Duration;
  import org.joda.time.Instant;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for Sessions WindowFn. */
  @RunWith(JUnit4.class)
  public class SessionsTest {
    @Rule public ExpectedException thrown = ExpectedException.none();
  
    @Test
    public void testSimple() throws Exception {
      Map<IntervalWindow, Set<String>> expected = new HashMap<>();
      expected.put(new IntervalWindow(new Instant(0), new Instant(10)), set(0));
      expected.put(new IntervalWindow(new Instant(10), new Instant(20)), set(10));
      expected.put(new IntervalWindow(new Instant(101), new Instant(111)), set(101));
      assertEquals(
          expected,
          runWindowFn(Sessions.withGapDuration(Duration.millis(10)), Arrays.asList(0L, 10L, 101L)));
    }
  
    @Test
    public void testConsecutive() throws Exception {
      Map<IntervalWindow, Set<String>> expected = new HashMap<>();
      expected.put(new IntervalWindow(new Instant(1), new Instant(19)), set(1, 2, 5, 9));
      expected.put(new IntervalWindow(new Instant(100), new Instant(111)), set(100, 101));
      assertEquals(
          expected,
          runWindowFn(
              Sessions.withGapDuration(Duration.millis(10)),
              Arrays.asList(1L, 2L, 5L, 9L, 100L, 101L)));
    }
  
    @Test
    public void testMerging() throws Exception {
      Map<IntervalWindow, Set<String>> expected = new HashMap<>();
      expected.put(new IntervalWindow(new Instant(1), new Instant(40)), set(1, 10, 15, 22, 30));
      expected.put(new IntervalWindow(new Instant(95), new Instant(111)), set(95, 100, 101));
      assertEquals(
          expected,
          runWindowFn(
              Sessions.withGapDuration(Duration.millis(10)),
              Arrays.asList(1L, 15L, 30L, 100L, 101L, 95L, 22L, 10L)));
    }
  
    @Test
    public void testTimeUnit() throws Exception {
      Map<IntervalWindow, Set<String>> expected = new HashMap<>();
      expected.put(new IntervalWindow(new Instant(1), new Instant(2000)), set(1, 2, 1000));
      expected.put(new IntervalWindow(new Instant(5000), new Instant(6001)), set(5000, 5001));
      expected.put(new IntervalWindow(new Instant(10000), new Instant(11000)), set(10000));
      assertEquals(
          expected,
          runWindowFn(
              Sessions.withGapDuration(Duration.standardSeconds(1)),
              Arrays.asList(1L, 2L, 1000L, 5000L, 5001L, 10000L)));
    }
  
    @Test
    public void testEquality() {
      assertTrue(
          Sessions.withGapDuration(Duration.millis(10))
              .isCompatible(Sessions.withGapDuration(Duration.millis(10))));
      assertTrue(
          Sessions.withGapDuration(Duration.millis(10))
              .isCompatible(Sessions.withGapDuration(Duration.millis(20))));
    }
  
    @Test
    public void testVerifyCompatibility() throws IncompatibleWindowException {
      Sessions.withGapDuration(Duration.millis(10))
          .verifyCompatibility(Sessions.withGapDuration(Duration.millis(10)));
  
      thrown.expect(IncompatibleWindowException.class);
      Sessions.withGapDuration(Duration.millis(10))
          .verifyCompatibility(FixedWindows.of(Duration.millis(10)));
    }
  
    /**
     * Test to confirm that {@link Sessions} with the default {@link TimestampCombiner} holds up the
     * watermark potentially indefinitely.
     */
    @Test
    public void testInvalidOutputAtEarliest() throws Exception {
      try {
        WindowFnTestUtils.validateGetOutputTimestamps(
            Sessions.withGapDuration(Duration.millis(10)),
            TimestampCombiner.EARLIEST,
            ImmutableList.of(
                (List<Long>) ImmutableList.of(1L, 3L),
                (List<Long>) ImmutableList.of(0L, 5L, 10L, 15L, 20L)));
      } catch (AssertionError exc) {
        assertThat(
            exc.getMessage(),
            // These are the non-volatile pieces of the error message that a timestamp
            // was not greater than what it should be.
            allOf(containsString("a value greater than"), containsString("was less than")));
      }
    }
  
    /**
     * When a user explicitly requests per-key aggregate values have their derived timestamp to be the
     * end of the window (instead of the earliest possible), the session here should not hold each
     * other up, even though they overlap.
     */
    @Test
    public void testValidOutputAtEndTimes() throws Exception {
      WindowFnTestUtils.validateGetOutputTimestamps(
          Sessions.withGapDuration(Duration.millis(10)),
          TimestampCombiner.END_OF_WINDOW,
          ImmutableList.of(
              (List<Long>) ImmutableList.of(1L, 3L),
              (List<Long>) ImmutableList.of(0L, 5L, 10L, 15L, 20L)));
    }
  
    @Test
    public void testDisplayData() {
      Duration gapDuration = Duration.standardMinutes(234);
      Sessions session = Sessions.withGapDuration(gapDuration);
      assertThat(DisplayData.from(session), hasDisplayItem("gapDuration", gapDuration));
    }
  }
  