/*
 * 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.reef.wake.test;

import org.apache.reef.wake.EventHandler;
import org.apache.reef.wake.impl.BlockingSignalEventHandler;
import org.junit.Test;

import java.util.concurrent.atomic.AtomicInteger;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

/**
 * Blocking signal event handler test.
 */
public class BlockingSignalEventHandlerTest {

  @Test
  public void testSingle() {
    final AtomicInteger cnt = new AtomicInteger(0);

    final BlockingSignalEventHandler<Integer> h = new BlockingSignalEventHandler<>(1, new EventHandler<Integer>() {
      @Override
      public void onNext(final Integer value) {
        cnt.incrementAndGet();
      }
    });
    h.onNext(0xBEEF);
    assertEquals(1, cnt.get());
  }

  @Test
  public void testMultiple() {
    final AtomicInteger cnt = new AtomicInteger(0);

    final BlockingSignalEventHandler<Integer> h = new BlockingSignalEventHandler<>(2, new EventHandler<Integer>() {
      @Override
      public void onNext(final Integer value) {
        cnt.incrementAndGet();
      }
    });
    h.onNext(1);
    h.onNext(2);
    assertEquals(1, cnt.get());
  }

  @Test
  public void testTwoStreams() {
    final AtomicInteger cnt = new AtomicInteger(0);

    final int num = 1000;
    final BlockingSignalEventHandler<Integer> h =
        new BlockingSignalEventHandler<>(2 * num, new EventHandler<Integer>() {
          @Override
          public void onNext(final Integer value) {
            cnt.incrementAndGet();
          }
        });

    final Runnable r = new Runnable() {
      @Override
      public void run() {
        for (int i = 0; i < num; i++) {
          h.onNext(i);
        }
      }
    };
    final Thread a = new Thread(r);
    final Thread b = new Thread(r);
    a.start();
    b.start();
    try {
      a.join();
      b.join();
    } catch (final InterruptedException e) {
      fail(e.toString());
    }

    assertEquals(1, cnt.get());
  }

  @Test
  public void testMultipleResets() {
    final AtomicInteger cnt = new AtomicInteger(0);

    final int num = 1000;
    final int events = 10;
    final BlockingSignalEventHandler<Integer> h = new BlockingSignalEventHandler<>(2 * num,
        new EventHandler<Integer>() {
          @Override
          public void onNext(final Integer value) {
            cnt.incrementAndGet();
          }
        });

    final Runnable r = new Runnable() {
      @Override
      public void run() {
        for (int i = 0; i < num * events; i++) {
          h.onNext(i);
        }
      }
    };
    final Thread a = new Thread(r);
    final Thread b = new Thread(r);
    a.start();
    b.start();
    try {
      a.join();
      b.join();
    } catch (final InterruptedException e) {
      fail(e.toString());
    }

    assertEquals(events, cnt.get());
  }

  @Test
  public void testManyStreams() {
    final AtomicInteger cnt = new AtomicInteger(0);

    final int num = 1000;
    final BlockingSignalEventHandler<Integer> h = new BlockingSignalEventHandler<>(num, new EventHandler<Integer>() {
      @Override
      public void onNext(final Integer value) {
        cnt.incrementAndGet();
      }
    });

    final int val = 7;
    final Runnable r = new Runnable() {
      @Override
      public void run() {
        h.onNext(val);
      }
    };

    final Thread[] workers = new Thread[num];
    for (int ii = 0; ii < workers.length; ii++) {
      workers[ii] = new Thread(r);
    }
    for (final Thread w : workers) {
      w.start();
    }
    try {
      for (final Thread w : workers) {
        w.join();
      }
    } catch (final InterruptedException e) {
      fail(e.toString());
    }

    assertEquals(1, cnt.get());

  }

}