/*
 * Copyright (C) 2011 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;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import com.google.common.testing.NullPointerTester;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import junit.framework.TestCase;

/**
 * Tests for {@link AtomicLongMap}.
 *
 * @author mike nonemacher
 */
@GwtCompatible(emulated = true)
public class AtomicLongMapTest extends TestCase {
  private static final int ITERATIONS = 100;
  private static final int MAX_ADDEND = 100;

  private Random random = new Random(301);

  @GwtIncompatible // NullPointerTester
  public void testNulls() {
    NullPointerTester tester = new NullPointerTester();
    tester.testAllPublicConstructors(AtomicLongMap.class);
    tester.testAllPublicStaticMethods(AtomicLongMap.class);
    AtomicLongMap<Object> map = AtomicLongMap.create();
    tester.testAllPublicInstanceMethods(map);
  }

  public void testCreate_map() {
    Map<String, Long> in = ImmutableMap.of("1", 1L, "2", 2L, "3", 3L);
    AtomicLongMap<String> map = AtomicLongMap.create(in);
    assertFalse(map.isEmpty());
    assertSame(3, map.size());
    assertTrue(map.containsKey("1"));
    assertTrue(map.containsKey("2"));
    assertTrue(map.containsKey("3"));
    assertEquals(1L, map.get("1"));
    assertEquals(2L, map.get("2"));
    assertEquals(3L, map.get("3"));
  }

  public void testIncrementAndGet() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.incrementAndGet(key);
      long after = map.get(key);
      assertEquals(before + 1, after);
      assertEquals(after, result);
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
    assertEquals(ITERATIONS, (int) map.get(key));
  }

  public void testIncrementAndGet_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(1L, map.incrementAndGet(key));
    assertEquals(1L, map.get(key));

    assertEquals(0L, map.decrementAndGet(key));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(1L, map.incrementAndGet(key));
    assertEquals(1L, map.get(key));
  }

  public void testGetAndIncrement() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.getAndIncrement(key);
      long after = map.get(key);
      assertEquals(before + 1, after);
      assertEquals(before, result);
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
    assertEquals(ITERATIONS, (int) map.get(key));
  }

  public void testGetAndIncrement_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.getAndIncrement(key));
    assertEquals(1L, map.get(key));

    assertEquals(1L, map.getAndDecrement(key));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.getAndIncrement(key));
    assertEquals(1L, map.get(key));
  }

  public void testDecrementAndGet() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.decrementAndGet(key);
      long after = map.get(key);
      assertEquals(before - 1, after);
      assertEquals(after, result);
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
    assertEquals(-1 * ITERATIONS, (int) map.get(key));
  }

  public void testDecrementAndGet_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(-1L, map.decrementAndGet(key));
    assertEquals(-1L, map.get(key));

    assertEquals(0L, map.incrementAndGet(key));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(-1L, map.decrementAndGet(key));
    assertEquals(-1L, map.get(key));
  }

  public void testGetAndDecrement() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.getAndDecrement(key);
      long after = map.get(key);
      assertEquals(before - 1, after);
      assertEquals(before, result);
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
    assertEquals(-1 * ITERATIONS, (int) map.get(key));
  }

  public void testGetAndDecrement_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.getAndDecrement(key));
    assertEquals(-1L, map.get(key));

    assertEquals(-1L, map.getAndIncrement(key));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.getAndDecrement(key));
    assertEquals(-1L, map.get(key));
  }

  public void testAddAndGet() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long addend = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.addAndGet(key, addend);
      long after = map.get(key);
      assertEquals(before + addend, after);
      assertEquals(after, result);
      addend = after;
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
  }

  public void testAddAndGet_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long value = random.nextInt(MAX_ADDEND);
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(value, map.addAndGet(key, value));
    assertEquals(value, map.get(key));

    assertEquals(0L, map.addAndGet(key, -1 * value));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(value, map.addAndGet(key, value));
    assertEquals(value, map.get(key));
  }

  public void testGetAndAdd() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long addend = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.getAndAdd(key, addend);
      long after = map.get(key);
      assertEquals(before + addend, after);
      assertEquals(before, result);
      addend = after;
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
  }

  public void testGetAndAdd_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long value = random.nextInt(MAX_ADDEND);
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.getAndAdd(key, value));
    assertEquals(value, map.get(key));

    assertEquals(value, map.getAndAdd(key, -1 * value));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.getAndAdd(key, value));
    assertEquals(value, map.get(key));
  }

  public void testPut() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.put(key, newValue);
      long after = map.get(key);
      assertEquals(newValue, after);
      assertEquals(before, result);
      newValue += newValue;
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
  }

  public void testPut_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long value = random.nextInt(MAX_ADDEND);
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.put(key, value));
    assertEquals(value, map.get(key));

    assertEquals(value, map.put(key, 0L));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.put(key, value));
    assertEquals(value, map.get(key));
  }

  public void testPutAll() {
    Map<String, Long> in = ImmutableMap.of("1", 1L, "2", 2L, "3", 3L);
    AtomicLongMap<String> map = AtomicLongMap.create();
    assertTrue(map.isEmpty());
    assertSame(0, map.size());
    assertFalse(map.containsKey("1"));
    assertFalse(map.containsKey("2"));
    assertFalse(map.containsKey("3"));
    assertEquals(0L, map.get("1"));
    assertEquals(0L, map.get("2"));
    assertEquals(0L, map.get("3"));

    map.putAll(in);
    assertFalse(map.isEmpty());
    assertSame(3, map.size());
    assertTrue(map.containsKey("1"));
    assertTrue(map.containsKey("2"));
    assertTrue(map.containsKey("3"));
    assertEquals(1L, map.get("1"));
    assertEquals(2L, map.get("2"));
    assertEquals(3L, map.get("3"));
  }

  public void testPutIfAbsent() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      long result = map.putIfAbsent(key, newValue);
      long after = map.get(key);
      assertEquals(before, result);
      assertEquals(before == 0 ? newValue : before, after);

      map.remove(key);
      before = map.get(key);
      result = map.putIfAbsent(key, newValue);
      after = map.get(key);
      assertEquals(0, before);
      assertEquals(before, result);
      assertEquals(newValue, after);

      map.put(key, 0L);
      before = map.get(key);
      result = map.putIfAbsent(key, newValue);
      after = map.get(key);
      assertEquals(0, before);
      assertEquals(before, result);
      assertEquals(newValue, after);

      newValue += newValue;
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
  }

  public void testPutIfAbsent_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long value = random.nextInt(MAX_ADDEND);
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.putIfAbsent(key, value));
    assertEquals(value, map.get(key));

    assertEquals(value, map.put(key, 0L));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.putIfAbsent(key, value));
    assertEquals(value, map.get(key));
  }

  public void testReplace() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      assertFalse(map.replace(key, before + 1, newValue + 1));
      assertFalse(map.replace(key, before - 1, newValue - 1));
      assertTrue(map.replace(key, before, newValue));
      long after = map.get(key);
      assertEquals(newValue, after);
      newValue += newValue;
    }
    assertEquals(1, map.size());
    assertTrue(!map.isEmpty());
    assertTrue(map.containsKey(key));
  }

  public void testReplace_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    long value = random.nextInt(MAX_ADDEND);
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertTrue(map.replace(key, 0L, value));
    assertEquals(value, map.get(key));

    assertTrue(map.replace(key, value, 0L));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertTrue(map.replace(key, 0L, value));
    assertEquals(value, map.get(key));
  }

  public void testRemove() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
    assertEquals(0L, map.remove(key));

    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      map.put(key, newValue);
      assertTrue(map.containsKey(key));

      long before = map.get(key);
      long result = map.remove(key);
      long after = map.get(key);
      assertFalse(map.containsKey(key));
      assertEquals(before, result);
      assertEquals(0L, after);
      newValue += newValue;
    }
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
  }

  public void testRemove_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.remove(key));
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.put(key, 0L));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertEquals(0L, map.remove(key));
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));
  }

  public void testRemoveIfZero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
    assertFalse(map.removeIfZero(key));

    assertEquals(1, map.incrementAndGet(key));
    assertFalse(map.removeIfZero(key));
    assertEquals(2, map.incrementAndGet(key));
    assertFalse(map.removeIfZero(key));
    assertEquals(1, map.decrementAndGet(key));
    assertFalse(map.removeIfZero(key));
    assertEquals(0, map.decrementAndGet(key));
    assertTrue(map.removeIfZero(key));
    assertFalse(map.containsKey(key));
  }

  public void testRemoveValue() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
    assertFalse(map.remove(key, 0L));

    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      map.put(key, newValue);
      assertTrue(map.containsKey(key));

      long before = map.get(key);
      assertFalse(map.remove(key, newValue + 1));
      assertFalse(map.remove(key, newValue - 1));
      assertTrue(map.remove(key, newValue));
      long after = map.get(key);
      assertFalse(map.containsKey(key));
      assertEquals(0L, after);
      newValue += newValue;
    }
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
  }

  public void testRemoveValue_zero() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    String key = "key";
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertFalse(map.remove(key, 0L));
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));

    assertEquals(0L, map.put(key, 0L));
    assertEquals(0L, map.get(key));
    assertTrue(map.containsKey(key));

    assertTrue(map.remove(key, 0L));
    assertEquals(0L, map.get(key));
    assertFalse(map.containsKey(key));
  }

  public void testRemoveZeros() {
    AtomicLongMap<Object> map = AtomicLongMap.create();
    Set<Object> nonZeroKeys = Sets.newHashSet();
    for (int i = 0; i < ITERATIONS; i++) {
      Object key = new Object();
      long value = i % 2;
      map.put(key, value);
      if (value != 0L) {
        nonZeroKeys.add(key);
      }
    }
    assertEquals(ITERATIONS, map.size());
    assertTrue(map.asMap().containsValue(0L));

    map.removeAllZeros();
    assertFalse(map.asMap().containsValue(0L));
    assertEquals(ITERATIONS / 2, map.size());
    assertEquals(nonZeroKeys, map.asMap().keySet());
  }

  public void testClear() {
    AtomicLongMap<Object> map = AtomicLongMap.create();
    for (int i = 0; i < ITERATIONS; i++) {
      map.put(new Object(), i);
    }
    assertEquals(ITERATIONS, map.size());

    map.clear();
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
  }

  public void testSum() {
    AtomicLongMap<Object> map = AtomicLongMap.create();
    long sum = 0;
    for (int i = 0; i < ITERATIONS; i++) {
      map.put(new Object(), i);
      sum += i;
    }
    assertEquals(ITERATIONS, map.size());
    assertEquals(sum, map.sum());
  }

  public void testEmpty() {
    AtomicLongMap<String> map = AtomicLongMap.create();
    assertEquals(0L, map.get("a"));
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
    assertFalse(map.remove("a", 1L));
    assertFalse(map.remove("a", 0L));
    assertFalse(map.replace("a", 1L, 0L));
  }

  @GwtIncompatible // threads
  public void testModify_basher() throws InterruptedException {
    int nTasks = 3000;
    int nThreads = 100;
    final int getsPerTask = 1000;
    final int deltaRange = 10000;
    final String key = "key";

    final AtomicLong sum = new AtomicLong();
    final AtomicLongMap<String> map = AtomicLongMap.create();

    ExecutorService threadPool = Executors.newFixedThreadPool(nThreads);
    for (int i = 0; i < nTasks; i++) {
      threadPool.submit(new Runnable() {
        @Override public void run() {
          int threadSum = 0;
          for (int j = 0; j < getsPerTask; j++) {
            long delta = random.nextInt(deltaRange);
            int behavior = random.nextInt(10);
            switch (behavior) {
              case 0:
                map.incrementAndGet(key);
                threadSum++;
                break;
              case 1:
                map.decrementAndGet(key);
                threadSum--;
                break;
              case 2:
                map.addAndGet(key, delta);
                threadSum += delta;
                break;
              case 3:
                map.getAndIncrement(key);
                threadSum++;
                break;
              case 4:
                map.getAndDecrement(key);
                threadSum--;
                break;
              case 5:
                map.getAndAdd(key, delta);
                threadSum += delta;
                break;
              case 6:
                long oldValue = map.put(key, delta);
                threadSum += delta - oldValue;
                break;
              case 7:
                oldValue = map.get(key);
                if (map.replace(key, oldValue, delta)) {
                  threadSum += delta - oldValue;
                }
                break;
              case 8:
                oldValue = map.remove(key);
                threadSum -= oldValue;
                break;
              case 9:
                oldValue = map.get(key);
                if (map.remove(key, oldValue)) {
                  threadSum -= oldValue;
                }
                break;
              default:
                throw new AssertionError();
            }
          }
          sum.addAndGet(threadSum);
        }
      });
    }

    threadPool.shutdown();
    assertTrue(threadPool.awaitTermination(300, TimeUnit.SECONDS));

    assertEquals(sum.get(), map.get(key));
  }
}
