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 com.datastax.oss.driver.internal.core.util;
  
  import static com.datastax.oss.driver.Assertions.assertThat;
  import static org.mockito.Mockito.anyInt;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.when;
  
  import java.util.Random;
  import org.junit.Test;
  
  public class ArrayUtilsTest {
  
    @Test
    public void should_swap() {
      String[] array = {"a", "b", "c"};
      ArrayUtils.swap(array, 0, 2);
      assertThat(array).containsExactly("c", "b", "a");
    }
  
    @Test
    public void should_swap_with_same_index() {
      String[] array = {"a", "b", "c"};
      ArrayUtils.swap(array, 0, 0);
      assertThat(array).containsExactly("a", "b", "c");
    }
  
    @Test
    public void should_bubble_up() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleUp(array, 3, 1);
      assertThat(array).containsExactly("a", "d", "b", "c", "e");
    }
  
    @Test
    public void should_bubble_up_to_same_index() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleUp(array, 3, 3);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  
    @Test
    public void should_not_bubble_up_when_target_index_higher() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleUp(array, 3, 5);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  
    @Test
    public void should_bubble_down() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleDown(array, 1, 3);
      assertThat(array).containsExactly("a", "c", "d", "b", "e");
    }
  
    @Test
    public void should_bubble_down_to_same_index() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleDown(array, 3, 3);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  
    @Test
    public void should_not_bubble_down_when_target_index_lower() {
      String[] array = {"a", "b", "c", "d", "e"};
      ArrayUtils.bubbleDown(array, 4, 2);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  
    @Test
    public void should_shuffle_head() {
      String[] array = {"a", "b", "c", "d", "e"};
      Random random = mock(Random.class);
      when(random.nextInt(anyInt()))
          .thenAnswer(
              (invocation) -> {
                int i = invocation.getArgument(0);
                // shifts elements by 1 to the right
                return i - 2;
              });
      ArrayUtils.shuffleHead(array, 3, random);
      assertThat(array[0]).isEqualTo("c");
      assertThat(array[1]).isEqualTo("a");
      assertThat(array[2]).isEqualTo("b");
      // Tail elements should not move
      assertThat(array[3]).isEqualTo("d");
      assertThat(array[4]).isEqualTo("e");
    }
  
    @Test(expected = ArrayIndexOutOfBoundsException.class)
    public void should_fail_to_shuffle_head_when_count_is_too_high() {
      ArrayUtils.shuffleHead(new String[] {"a", "b", "c"}, 5);
    }
  
    @Test
    public void should_rotate() {
      String[] array = {"a", "b", "c", "d", "e"};
  
      ArrayUtils.rotate(array, 1, 3, 1);
      assertThat(array).containsExactly("a", "c", "d", "b", "e");
  
      ArrayUtils.rotate(array, 0, 4, 2);
      assertThat(array).containsExactly("d", "b", "a", "c", "e");
  
      ArrayUtils.rotate(array, 2, 3, 10);
      assertThat(array).containsExactly("d", "b", "c", "e", "a");
    }
  
    @Test
    public void should_not_rotate_when_amount_multiple_of_range_size() {
      String[] array = {"a", "b", "c", "d", "e"};
  
      ArrayUtils.rotate(array, 1, 3, 9);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  
    @Test
    public void should_not_rotate_when_range_is_singleton_or_empty() {
      String[] array = {"a", "b", "c", "d", "e"};
  
      ArrayUtils.rotate(array, 1, 1, 3);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
  
      ArrayUtils.rotate(array, 1, 0, 3);
      assertThat(array).containsExactly("a", "b", "c", "d", "e");
    }
  }
  