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.samza.adapter;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.Callable;
  import java.util.concurrent.CountDownLatch;
  import org.apache.beam.runners.samza.runtime.OpMessage;
  import org.apache.beam.sdk.io.Source;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.values.WindowedValues;
  import org.apache.samza.system.IncomingMessageEnvelope;
  import org.apache.samza.system.SystemStreamPartition;
  import org.joda.time.Instant;
  
  /** Helper classes and functions to build source for testing. */
  public class TestSourceHelpers {
  
    private TestSourceHelpers() {}
  
    interface Event<T> {}
  
    static class ElementEvent<T> implements Event<T> {
      final T element;
      final Instant timestamp;
  
      private ElementEvent(T element, Instant timestamp) {
        this.element = element;
        this.timestamp = timestamp;
      }
    }
  
    static class WatermarkEvent<T> implements Event<T> {
      final Instant watermark;
  
      private WatermarkEvent(Instant watermark) {
        this.watermark = watermark;
      }
    }
  
    static class ExceptionEvent<T> implements Event<T> {
      final IOException exception;
  
      private ExceptionEvent(IOException exception) {
        this.exception = exception;
      }
    }
  
    static class LatchEvent<T> implements Event<T> {
      final CountDownLatch latch;
  
      private LatchEvent(CountDownLatch latch) {
        this.latch = latch;
      }
    }
  
    static class NoElementEvent<T> implements Event<T> {}
  
    /** A builder used to populate the events emitted by {@link TestBoundedSource}. */
    abstract static class SourceBuilder<T, W extends Source<T>> {
      private final List<Event<T>> events = new ArrayList<>();
      private Instant currentTimestamp = BoundedWindow.TIMESTAMP_MIN_VALUE;
  
      @SafeVarargs
      public final SourceBuilder<T, W> addElements(T... elements) {
        for (T element : elements) {
          events.add(new ElementEvent<>(element, currentTimestamp));
        }
        return this;
      }
  
      public SourceBuilder<T, W> addException(IOException exception) {
        events.add(new ExceptionEvent<>(exception));
        return this;
      }
  
      public SourceBuilder<T, W> addLatch(CountDownLatch latch) {
        events.add(new LatchEvent<>(latch));
        return this;
      }
  
      public SourceBuilder<T, W> setTimestamp(Instant timestamp) {
        assertTrue(
            "Expected " + timestamp + " to be greater than or equal to " + currentTimestamp,
            timestamp.isEqual(currentTimestamp) || timestamp.isAfter(currentTimestamp));
        currentTimestamp = timestamp;
        return this;
      }
  
      public SourceBuilder<T, W> advanceWatermarkTo(Instant watermark) {
        events.add(new WatermarkEvent<>(watermark));
        return this;
      }
  
      public SourceBuilder<T, W> noElements() {
        events.add(new NoElementEvent<T>());
        return this;
      }
  
      protected List<Event<T>> getEvents() {
        return this.events;
      }
  
      public abstract W build();
    }
  
    static IncomingMessageEnvelope createElementMessage(
        SystemStreamPartition ssp, String offset, String element, Instant timestamp) {
      return new IncomingMessageEnvelope(
          ssp,
          offset,
          null,
          OpMessage.ofElement(WindowedValues.timestampedValueInGlobalWindow(element, timestamp)));
    }
  
    static IncomingMessageEnvelope createWatermarkMessage(
        SystemStreamPartition ssp, Instant watermark) {
      return IncomingMessageEnvelope.buildWatermarkEnvelope(ssp, watermark.getMillis());
    }
  
    static IncomingMessageEnvelope createEndOfStreamMessage(SystemStreamPartition ssp) {
      return IncomingMessageEnvelope.buildEndOfStreamEnvelope(ssp);
    }
  
    static <T> void expectWrappedException(Exception expectedException, Callable<T> callable)
        throws Exception {
      try {
        callable.call();
        fail("Expected exception (" + expectedException + "), but no exception was thrown");
      } catch (Exception e) {
        Throwable currentException = e;
        while (currentException != null) {
          if (currentException.equals(expectedException)) {
            return;
          }
          currentException = currentException.getCause();
        }
        assertEquals(expectedException, e);
      }
    }
  }
  