/*
 * Copyright (C) 2012 The Guava Authors
 *
 * Licensed 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 com.google.common.util.concurrent.testing;

import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListeningScheduledExecutorService;

import junit.framework.TestCase;

import java.lang.InterruptedException;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

/**
 * Tests for TestingExecutors.
 *
 * @author Eric Chang
 */
public class TestingExecutorsTest extends TestCase {
  private volatile boolean taskDone;

  public void testNoOpScheduledExecutor() throws InterruptedException {
    taskDone = false;
    Runnable task = new Runnable() {
      @Override public void run() {
        taskDone = true;
      }
    };
    ScheduledFuture<?> future = TestingExecutors.noOpScheduledExecutor().schedule(
        task, 10, TimeUnit.MILLISECONDS);
    Thread.sleep(20);
    assertFalse(taskDone);
    assertFalse(future.isDone());
  }

  public void testNoOpScheduledExecutorShutdown() {
    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    assertFalse(executor.isShutdown());
    assertFalse(executor.isTerminated());
    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertTrue(executor.isTerminated());
  }

  public void testNoOpScheduledExecutorInvokeAll() throws ExecutionException, InterruptedException {
    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    taskDone = false;
    Callable<Boolean> task = new Callable<Boolean>() {
      @Override public Boolean call() {
        taskDone = true;
        return taskDone;
      }
    };
    List<Future<Boolean>> futureList = executor.invokeAll(
        ImmutableList.of(task), 10, TimeUnit.MILLISECONDS);
    Future<Boolean> future = futureList.get(0);
    assertFalse(taskDone);
    assertTrue(future.isDone());
    try {
      future.get();
      fail();
    } catch (CancellationException e) {
      // pass
    }
  }

  public void testSameThreadScheduledExecutor() throws ExecutionException, InterruptedException {
    taskDone = false;
    Callable<Integer> task = new Callable<Integer>() {
      @Override public Integer call() {
        taskDone = true;
        return 6;
      }
    };
    Future<Integer> future = TestingExecutors.sameThreadScheduledExecutor().schedule(
        task, 10000, TimeUnit.MILLISECONDS);
    assertTrue("Should run callable immediately", taskDone);
    assertEquals(6, (int) future.get());
  }

  public void testSameThreadScheduledExecutorWithException() throws InterruptedException {
    Runnable runnable = new Runnable() {
      @Override public void run() {
        throw new RuntimeException("Oh no!");
      }
    };

    Future<?> future = TestingExecutors.sameThreadScheduledExecutor().submit(runnable);
    try {
      future.get();
      fail("Should have thrown exception");
    } catch (ExecutionException e) {
      // pass
    }
  }
}