/**
 * 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.hadoop.hbase.util;

import static org.hamcrest.CoreMatchers.startsWith;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.IOException;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Stream;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseIOException;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.junit.After;
import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;

import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;

@Category({ MiscTests.class, SmallTests.class })
public class TestFutureUtils {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
    HBaseClassTestRule.forClass(TestFutureUtils.class);

  private ExecutorService executor;

  @Before
  public void setUp() {
    executor = Executors.newFixedThreadPool(1, new ThreadFactoryBuilder().setDaemon(true).build());
  }

  @After
  public void tearDown() {
    executor.shutdownNow();
  }

  @Test
  public void testRecordStackTrace() throws IOException {
    CompletableFuture<Void> future = new CompletableFuture<>();
    executor.execute(() -> future.completeExceptionally(new HBaseIOException("Inject error!")));
    try {
      FutureUtils.get(future);
      fail("The future should have been completed exceptionally");
    } catch (HBaseIOException e) {
      assertEquals("Inject error!", e.getMessage());
      StackTraceElement[] elements = e.getStackTrace();
      assertThat(elements[0].toString(), startsWith("java.lang.Thread.getStackTrace"));
      assertThat(elements[1].toString(),
        startsWith("org.apache.hadoop.hbase.util.FutureUtils.setStackTrace"));
      assertThat(elements[2].toString(),
        startsWith("org.apache.hadoop.hbase.util.FutureUtils.rethrow"));
      assertThat(elements[3].toString(),
        startsWith("org.apache.hadoop.hbase.util.FutureUtils.get"));
      assertThat(elements[4].toString(),
        startsWith("org.apache.hadoop.hbase.util.TestFutureUtils.testRecordStackTrace"));
      assertTrue(Stream.of(elements)
        .anyMatch(element -> element.toString().contains("--------Future.get--------")));
    } catch (Throwable t) {
      throw new AssertionError("Caught unexpected Throwable", t);
    }
  }
}
