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.runners.core.triggers;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.equalTo;
  import static org.hamcrest.Matchers.nullValue;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  import static org.mockito.Mockito.doNothing;
  import static org.mockito.Mockito.verify;
  import static org.mockito.Mockito.when;
  
  import org.apache.beam.runners.core.triggers.TriggerStateMachine.OnMergeContext;
  import org.apache.beam.runners.core.triggers.TriggerStateMachineTester.SimpleTriggerStateMachineTester;
  import org.apache.beam.sdk.state.TimeDomain;
  import org.apache.beam.sdk.transforms.windowing.FixedWindows;
  import org.apache.beam.sdk.transforms.windowing.IntervalWindow;
  import org.apache.beam.sdk.transforms.windowing.Sessions;
  import org.joda.time.Duration;
  import org.joda.time.Instant;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  import org.mockito.Mock;
  import org.mockito.Mockito;
  import org.mockito.MockitoAnnotations;
  
  /** Tests the {@link AfterWatermarkStateMachine} triggers. */
  @RunWith(JUnit4.class)
  public class AfterWatermarkStateMachineTest {
  
    @Mock private TriggerStateMachine mockEarly;
    @Mock private TriggerStateMachine mockLate;
  
    private SimpleTriggerStateMachineTester<IntervalWindow> tester;
  
    private static TriggerStateMachine.TriggerContext anyTriggerContext() {
      return Mockito.any();
    }
  
    private static TriggerStateMachine.OnElementContext anyElementContext() {
      return Mockito.any();
    }
  
    private void injectElements(int... elements) throws Exception {
      for (int element : elements) {
        doNothing().when(mockEarly).onElement(anyElementContext());
        doNothing().when(mockLate).onElement(anyElementContext());
        tester.injectElements(element);
      }
    }
  
    @Before
    public void setUp() {
      MockitoAnnotations.initMocks(this);
    }
  
    public void testRunningAsTrigger(TriggerStateMachine mockTrigger, IntervalWindow window)
        throws Exception {
  
      // Don't fire due to mock saying no
      when(mockTrigger.shouldFire(anyTriggerContext())).thenReturn(false);
      assertFalse(tester.shouldFire(window)); // not ready
  
      // Fire due to mock trigger; early trigger is required to be a OnceTrigger
      when(mockTrigger.shouldFire(anyTriggerContext())).thenReturn(true);
      assertTrue(tester.shouldFire(window)); // ready
      tester.fireIfShouldFire(window);
      assertFalse(tester.isMarkedFinished(window));
    }
  
    @Test
    public void testEarlyAndAtWatermark() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow().withEarlyFirings(mockEarly),
              FixedWindows.of(Duration.millis(100)));
  
      injectElements(1);
      IntervalWindow window = new IntervalWindow(new Instant(0), new Instant(100));
  
      testRunningAsTrigger(mockEarly, window);
  
      // Fire due to watermark
      when(mockEarly.shouldFire(anyTriggerContext())).thenReturn(false);
      tester.advanceInputWatermark(new Instant(100));
      assertTrue(tester.shouldFire(window));
      tester.fireIfShouldFire(window);
      assertTrue(tester.isMarkedFinished(window));
    }
  
    @Test
    public void testTimerForEndOfWindow() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow(), FixedWindows.of(Duration.millis(100)));
  
      assertThat(tester.getNextTimer(TimeDomain.EVENT_TIME), nullValue());
      injectElements(1);
      IntervalWindow window = new IntervalWindow(new Instant(0), new Instant(100));
      assertThat(tester.getNextTimer(TimeDomain.EVENT_TIME), equalTo(window.maxTimestamp()));
    }
  
    @Test
    public void testTimerForEndOfWindowCompound() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow().withEarlyFirings(NeverStateMachine.ever()),
              FixedWindows.of(Duration.millis(100)));
  
      assertThat(tester.getNextTimer(TimeDomain.EVENT_TIME), nullValue());
      injectElements(1);
      IntervalWindow window = new IntervalWindow(new Instant(0), new Instant(100));
      assertThat(tester.getNextTimer(TimeDomain.EVENT_TIME), equalTo(window.maxTimestamp()));
    }
  
    @Test
    public void testAtWatermarkAndLate() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow().withLateFirings(mockLate),
              FixedWindows.of(Duration.millis(100)));
  
      injectElements(1);
      IntervalWindow window = new IntervalWindow(new Instant(0), new Instant(100));
  
      // No early firing, just double checking
      when(mockEarly.shouldFire(anyTriggerContext())).thenReturn(true);
      assertFalse(tester.shouldFire(window));
      tester.fireIfShouldFire(window);
      assertFalse(tester.isMarkedFinished(window));
  
      // Fire due to watermark
      when(mockEarly.shouldFire(anyTriggerContext())).thenReturn(false);
      tester.advanceInputWatermark(new Instant(100));
      assertTrue(tester.shouldFire(window));
      tester.fireIfShouldFire(window);
      assertFalse(tester.isMarkedFinished(window));
  
      testRunningAsTrigger(mockLate, window);
    }
  
    @Test
    public void testEarlyAndAtWatermarkAndLate() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow()
                  .withEarlyFirings(mockEarly)
                  .withLateFirings(mockLate),
              FixedWindows.of(Duration.millis(100)));
  
      injectElements(1);
      IntervalWindow window = new IntervalWindow(new Instant(0), new Instant(100));
  
      testRunningAsTrigger(mockEarly, window);
  
      // Fire due to watermark
      when(mockEarly.shouldFire(anyTriggerContext())).thenReturn(false);
      tester.advanceInputWatermark(new Instant(100));
      assertTrue(tester.shouldFire(window));
      tester.fireIfShouldFire(window);
      assertFalse(tester.isMarkedFinished(window));
  
      testRunningAsTrigger(mockLate, window);
    }
  
    /**
     * Tests that if the EOW is finished in both as well as the merged window, then it is finished in
     * the merged result.
     *
     * <p>Because windows are discarded when a trigger finishes, we need to embed this in a sequence
     * in order to check that it is re-activated. So this test is potentially sensitive to other
     * triggers' correctness.
     */
    @Test
    public void testOnMergeAlreadyFinished() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterEachStateMachine.inOrder(
                  AfterWatermarkStateMachine.pastEndOfWindow(),
                  RepeatedlyStateMachine.forever(AfterPaneStateMachine.elementCountAtLeast(1))),
              Sessions.withGapDuration(Duration.millis(10)));
  
      tester.injectElements(1);
      tester.injectElements(5);
      IntervalWindow firstWindow = new IntervalWindow(new Instant(1), new Instant(11));
      IntervalWindow secondWindow = new IntervalWindow(new Instant(5), new Instant(15));
      IntervalWindow mergedWindow = new IntervalWindow(new Instant(1), new Instant(15));
  
      // Finish the AfterWatermark.pastEndOfWindow() trigger in both windows
      tester.advanceInputWatermark(new Instant(15));
      assertTrue(tester.shouldFire(firstWindow));
      assertTrue(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
      tester.fireIfShouldFire(secondWindow);
  
      // Confirm that we are on the second trigger by probing
      assertFalse(tester.shouldFire(firstWindow));
      assertFalse(tester.shouldFire(secondWindow));
      tester.injectElements(1);
      tester.injectElements(5);
      assertTrue(tester.shouldFire(firstWindow));
      assertTrue(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
      tester.fireIfShouldFire(secondWindow);
  
      // Merging should leave it finished
      tester.mergeWindows();
  
      // Confirm that we are on the second trigger by probing
      assertFalse(tester.shouldFire(mergedWindow));
      tester.injectElements(1);
      assertTrue(tester.shouldFire(mergedWindow));
    }
  
    /**
     * Tests that the trigger rewinds to be non-finished in the merged window.
     *
     * <p>Because windows are discarded when a trigger finishes, we need to embed this in a sequence
     * in order to check that it is re-activated. So this test is potentially sensitive to other
     * triggers' correctness.
     */
    @Test
    public void testOnMergeRewinds() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterEachStateMachine.inOrder(
                  AfterWatermarkStateMachine.pastEndOfWindow(),
                  RepeatedlyStateMachine.forever(AfterPaneStateMachine.elementCountAtLeast(1))),
              Sessions.withGapDuration(Duration.millis(10)));
  
      tester.injectElements(1);
      tester.injectElements(5);
      IntervalWindow firstWindow = new IntervalWindow(new Instant(1), new Instant(11));
      IntervalWindow secondWindow = new IntervalWindow(new Instant(5), new Instant(15));
      IntervalWindow mergedWindow = new IntervalWindow(new Instant(1), new Instant(15));
  
      // Finish the AfterWatermark.pastEndOfWindow() trigger in only the first window
      tester.advanceInputWatermark(new Instant(11));
      assertTrue(tester.shouldFire(firstWindow));
      assertFalse(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
  
      // Confirm that we are on the second trigger by probing
      assertFalse(tester.shouldFire(firstWindow));
      tester.injectElements(1);
      assertTrue(tester.shouldFire(firstWindow));
      tester.fireIfShouldFire(firstWindow);
  
      // Merging should re-activate the watermark trigger in the merged window
      tester.mergeWindows();
  
      // Confirm that we are not on the second trigger by probing
      assertFalse(tester.shouldFire(mergedWindow));
      tester.injectElements(1);
      assertFalse(tester.shouldFire(mergedWindow));
  
      // And confirm that advancing the watermark fires again
      tester.advanceInputWatermark(new Instant(15));
      assertTrue(tester.shouldFire(mergedWindow));
    }
  
    /**
     * Tests that if the EOW is finished in both as well as the merged window, then it is finished in
     * the merged result.
     *
     * <p>Because windows are discarded when a trigger finishes, we need to embed this in a sequence
     * in order to check that it is re-activated. So this test is potentially sensitive to other
     * triggers' correctness.
     */
    @Test
    public void testEarlyAndLateOnMergeAlreadyFinished() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow()
                  .withEarlyFirings(AfterPaneStateMachine.elementCountAtLeast(100))
                  .withLateFirings(AfterPaneStateMachine.elementCountAtLeast(1)),
              Sessions.withGapDuration(Duration.millis(10)));
  
      tester.injectElements(1);
      tester.injectElements(5);
      IntervalWindow firstWindow = new IntervalWindow(new Instant(1), new Instant(11));
      IntervalWindow secondWindow = new IntervalWindow(new Instant(5), new Instant(15));
      IntervalWindow mergedWindow = new IntervalWindow(new Instant(1), new Instant(15));
  
      // Finish the AfterWatermark.pastEndOfWindow() bit of the trigger in both windows
      tester.advanceInputWatermark(new Instant(15));
      assertTrue(tester.shouldFire(firstWindow));
      assertTrue(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
      tester.fireIfShouldFire(secondWindow);
  
      // Confirm that we are on the late trigger by probing
      assertFalse(tester.shouldFire(firstWindow));
      assertFalse(tester.shouldFire(secondWindow));
      tester.injectElements(1);
      tester.injectElements(5);
      assertTrue(tester.shouldFire(firstWindow));
      assertTrue(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
      tester.fireIfShouldFire(secondWindow);
  
      // Merging should leave it on the late trigger
      tester.mergeWindows();
  
      // Confirm that we are on the late trigger by probing
      assertFalse(tester.shouldFire(mergedWindow));
      tester.injectElements(1);
      assertTrue(tester.shouldFire(mergedWindow));
    }
  
    @Test
    public void testEarlyAndLateOnMergeSubtriggerMerges() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow()
                  .withEarlyFirings(mockEarly)
                  .withLateFirings(mockLate),
              Sessions.withGapDuration(Duration.millis(10)));
  
      tester.injectElements(1);
      tester.injectElements(5);
  
      tester.mergeWindows();
      // Merging should re-activate the early trigger in the merged window
      verify(mockEarly).onMerge(Mockito.any(OnMergeContext.class));
      // Merging should merge the late trigger in the merged window so it can be cleared.
      verify(mockLate).onMerge(Mockito.any(OnMergeContext.class));
    }
  
    /**
     * Tests that the trigger rewinds to be non-finished in the merged window.
     *
     * <p>Because windows are discarded when a trigger finishes, we need to embed this in a sequence
     * in order to check that it is re-activated. So this test is potentially sensitive to other
     * triggers' correctness.
     */
    @Test
    public void testEarlyAndLateOnMergeRewinds() throws Exception {
      tester =
          TriggerStateMachineTester.forTrigger(
              AfterWatermarkStateMachine.pastEndOfWindow()
                  .withEarlyFirings(AfterPaneStateMachine.elementCountAtLeast(100))
                  .withLateFirings(AfterPaneStateMachine.elementCountAtLeast(1)),
              Sessions.withGapDuration(Duration.millis(10)));
  
      tester.injectElements(1);
      tester.injectElements(5);
      IntervalWindow firstWindow = new IntervalWindow(new Instant(1), new Instant(11));
      IntervalWindow secondWindow = new IntervalWindow(new Instant(5), new Instant(15));
      IntervalWindow mergedWindow = new IntervalWindow(new Instant(1), new Instant(15));
  
      // Finish the AfterWatermark.pastEndOfWindow() bit of the trigger in only the first window
      tester.advanceInputWatermark(new Instant(11));
      assertTrue(tester.shouldFire(firstWindow));
      assertFalse(tester.shouldFire(secondWindow));
      tester.fireIfShouldFire(firstWindow);
  
      // Confirm that we are on the late trigger by probing
      assertFalse(tester.shouldFire(firstWindow));
      tester.injectElements(1);
      assertTrue(tester.shouldFire(firstWindow));
      tester.fireIfShouldFire(firstWindow);
  
      // Merging should re-activate the early trigger in the merged window
      tester.mergeWindows();
  
      // Confirm that we are not on the second trigger by probing
      assertFalse(tester.shouldFire(mergedWindow));
      tester.injectElements(1);
      assertFalse(tester.shouldFire(mergedWindow));
  
      // And confirm that advancing the watermark fires again
      tester.advanceInputWatermark(new Instant(15));
      assertTrue(tester.shouldFire(mergedWindow));
    }
  
    @Test
    public void testFromEndOfWindowToString() {
      TriggerStateMachine trigger = AfterWatermarkStateMachine.pastEndOfWindow();
      assertEquals("AfterWatermark.pastEndOfWindow()", trigger.toString());
    }
  
    @Test
    public void testEarlyFiringsToString() {
      TriggerStateMachine trigger =
          AfterWatermarkStateMachine.pastEndOfWindow()
              .withEarlyFirings(StubTriggerStateMachine.named("t1"));
  
      assertEquals("AfterWatermark.pastEndOfWindow().withEarlyFirings(t1)", trigger.toString());
    }
  
    @Test
    public void testLateFiringsToString() {
      TriggerStateMachine trigger =
          AfterWatermarkStateMachine.pastEndOfWindow()
              .withLateFirings(StubTriggerStateMachine.named("t1"));
  
      assertEquals("AfterWatermark.pastEndOfWindow().withLateFirings(t1)", trigger.toString());
    }
  
    @Test
    public void testEarlyAndLateFiringsToString() {
      TriggerStateMachine trigger =
          AfterWatermarkStateMachine.pastEndOfWindow()
              .withEarlyFirings(StubTriggerStateMachine.named("t1"))
              .withLateFirings(StubTriggerStateMachine.named("t2"));
  
      assertEquals(
          "AfterWatermark.pastEndOfWindow().withEarlyFirings(t1).withLateFirings(t2)",
          trigger.toString());
    }
  
    @Test
    public void testToStringExcludesNeverTrigger() {
      TriggerStateMachine trigger =
          AfterWatermarkStateMachine.pastEndOfWindow()
              .withEarlyFirings(NeverStateMachine.ever())
              .withLateFirings(NeverStateMachine.ever());
  
      assertEquals("AfterWatermark.pastEndOfWindow()", trigger.toString());
    }
  }
  