/*
    * 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.commons.io.function;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Spliterator;
  import java.util.TreeSet;
  import java.util.concurrent.atomic.AtomicReference;
  
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link IOSpliterator}.
   */
  public class IOSpliteratorTest {
  
      private IOSpliterator<Path> spliterator;
  
      @BeforeEach
      public void beforeEach() {
          spliterator = IOSpliterator.adapt(newPathList().spliterator());
      }
  
      private List<Path> newPathList() {
          return Arrays.asList(TestConstants.ABS_PATH_A, TestConstants.ABS_PATH_B);
      }
  
      @Test
      public void testAdapt() {
          spliterator = IOSpliterator.adapt(newPathList().spliterator());
          assertEquals(2, spliterator.estimateSize());
      }
  
      @Test
      public void testAsSpliterator() {
          assertEquals(2, spliterator.estimateSize());
          assertEquals(2, spliterator.asSpliterator().estimateSize());
      }
  
      @Test
      public void testCharacteristics() {
          assertEquals(spliterator.unwrap().characteristics(), spliterator.characteristics());
          assertEquals(spliterator.unwrap().characteristics(), spliterator.asSpliterator().characteristics());
      }
  
      @Test
      public void testEstimateSize() {
          assertEquals(2, spliterator.estimateSize());
          assertEquals(spliterator.unwrap().estimateSize(), spliterator.estimateSize());
          assertEquals(spliterator.unwrap().estimateSize(), spliterator.asSpliterator().estimateSize());
      }
  
      @Test
      public void testForEachRemaining() {
          final List<Path> list = new ArrayList<>();
          spliterator.forEachRemaining(list::add);
          assertEquals(2, list.size());
          assertEquals(newPathList(), list);
      }
  
      @Test
      public void testForEachRemainingAsSpliterator() {
          final List<Path> list = new ArrayList<>();
          spliterator.asSpliterator().forEachRemaining(list::add);
          assertEquals(2, list.size());
          assertEquals(newPathList(), list);
      }
  
      @Test
      public void testGetComparator() {
          if (spliterator.hasCharacteristics(Spliterator.SORTED)) {
              assertEquals(spliterator.unwrap().getComparator(), spliterator.getComparator());
              assertEquals(spliterator.unwrap().getComparator(), spliterator.asSpliterator().getComparator());
          } else {
             assertThrows(IllegalStateException.class, () -> spliterator.unwrap().getComparator());
             assertThrows(IllegalStateException.class, () -> spliterator.asSpliterator().getComparator());
         }
         final IOSpliterator<Path> adapted = IOSpliterator.adapt(new TreeSet<>(newPathList()).stream().sorted().spliterator());
         final IOComparator<? super Path> comparator = adapted.getComparator();
         assertNull(comparator);
     }
 
     @Test
     public void testGetExactSizeIfKnown() {
         assertEquals(2, spliterator.getExactSizeIfKnown());
         assertEquals(spliterator.unwrap().getExactSizeIfKnown(), spliterator.getExactSizeIfKnown());
         assertEquals(spliterator.unwrap().getExactSizeIfKnown(), spliterator.asSpliterator().getExactSizeIfKnown());
     }
 
     @Test
     public void testHasCharacteristics() {
         assertTrue( spliterator.hasCharacteristics(spliterator.characteristics()));
         assertEquals(spliterator.unwrap().hasCharacteristics(spliterator.unwrap().characteristics()),
             spliterator.hasCharacteristics(spliterator.characteristics()));
         assertEquals(spliterator.unwrap().hasCharacteristics(spliterator.unwrap().characteristics()),
             spliterator.asSpliterator().hasCharacteristics(spliterator.asSpliterator().characteristics()));
     }
 
     @Test
     public void testTryAdvance() {
         final AtomicReference<Path> ref = new AtomicReference<>();
         assertTrue(spliterator.tryAdvance(ref::set));
         assertEquals(TestConstants.ABS_PATH_A, ref.get());
     }
 
     @Test
     public void testTrySplit() {
         final IOSpliterator<Path> trySplit = spliterator.trySplit();
         assertNotNull(trySplit);
         assertTrue(spliterator.getExactSizeIfKnown() > 0);
     }
 
     @Test
     public void testUnwrap() {
         assertNotNull(spliterator.unwrap());
     }
 
 }