/*
    * 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.collections4.queue;
  
  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.io.IOException;
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.Queue;
  
  import org.apache.commons.collections4.collection.AbstractCollectionTest;
  import org.junit.jupiter.api.Test;
  
  /**
   * Abstract test class for {@link java.util.Queue} methods and contracts.
   * <p>
   * To use, simply extend this class, and implement
   * the {@link #makeObject} method.
   * <p>
   * If your {@link Queue} fails one of these tests by design,
   * you may still use this base set of cases.  Simply override the
   * test case (method) your {@link Queue} fails or override one of the
   * protected methods from AbstractCollectionTest.
   */
  public abstract class AbstractQueueTest<E> extends AbstractCollectionTest<E> {
  
      /**
       * JUnit constructor.
       *
       * @param testName  the test class name
       */
      public AbstractQueueTest(final String testName) {
          super(testName);
      }
  
      /**
       * Returns the {@link #collection} field cast to a {@link Queue}.
       *
       * @return the collection field as a Queue
       */
      @Override
      public Queue<E> getCollection() {
          return (Queue<E>) super.getCollection();
      }
  
      /**
       *  Returns true if the collections produced by
       *  {@link #makeObject()} and {@link #makeFullCollection()}
       *  support the <code>set operation.<p>
       *  Default implementation returns true.  Override if your collection
       *  class does not support set.
       */
      public boolean isSetSupported() {
          return true;
      }
  
      /**
       * Returns an empty {@link ArrayList}.
       */
      @Override
      public Collection<E> makeConfirmedCollection() {
          return new ArrayList<>();
      }
  
      /**
       * Returns a full {@link ArrayList}.
       */
      @Override
      public Collection<E> makeConfirmedFullCollection() {
          return new ArrayList<>(Arrays.asList(getFullElements()));
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
     public Queue<E> makeFullCollection() {
         // only works if queue supports optional "addAll(Collection)"
         final Queue<E> queue = makeObject();
         queue.addAll(Arrays.asList(getFullElements()));
         return queue;
     }
 
     /**
      * Returns {@link #makeObject()}.
      *
      * @return an empty queue to be used for testing
      */
     @Override
     public abstract Queue<E> makeObject();
 
     /**
      * Compare the current serialized form of the Queue
      * against the canonical version in SCM.
      */
     @Test
     @SuppressWarnings("unchecked")
     public void testEmptyQueueCompatibility() throws IOException, ClassNotFoundException {
         /*
          * Create canonical objects with this code
         Queue queue = makeEmptyQueue();
         if (!(queue instanceof Serializable)) return;
 
         writeExternalFormToDisk((Serializable) queue, getCanonicalEmptyCollectionName(queue));
         */
 
         // test to make sure the canonical form has been preserved
         final Queue<E> queue = makeObject();
         if (queue instanceof Serializable && !skipSerializedCanonicalTests()
                 && isTestSerialization()) {
             final Queue<E> queue2 = (Queue<E>) readExternalFormFromDisk(getCanonicalEmptyCollectionName(queue));
             assertEquals(0, queue2.size(), "Queue is empty");
         }
     }
 
     @Test
     @SuppressWarnings("unchecked")
     public void testEmptyQueueSerialization() throws IOException, ClassNotFoundException {
         final Queue<E> queue = makeObject();
         if (!(queue instanceof Serializable && isTestSerialization())) {
             return;
         }
 
         final byte[] object = writeExternalFormToBytes((Serializable) queue);
         final Queue<E> queue2 = (Queue<E>) readExternalFormFromBytes(object);
 
         assertEquals(0, queue.size(), "Both queues are empty");
         assertEquals(0, queue2.size(), "Both queues are empty");
     }
 
     /**
      * Compare the current serialized form of the Queue
      * against the canonical version in SCM.
      */
     @Test
     @SuppressWarnings("unchecked")
     public void testFullQueueCompatibility() throws IOException, ClassNotFoundException {
         /*
          * Create canonical objects with this code
         Queue queue = makeFullQueue();
         if (!(queue instanceof Serializable)) return;
 
         writeExternalFormToDisk((Serializable) queue, getCanonicalFullCollectionName(queue));
         */
 
         // test to make sure the canonical form has been preserved
         final Queue<E> queue = makeFullCollection();
         if (queue instanceof Serializable && !skipSerializedCanonicalTests() && isTestSerialization()) {
             final Queue<E> queue2 = (Queue<E>) readExternalFormFromDisk(getCanonicalFullCollectionName(queue));
             assertEquals(queue.size(), queue2.size(), "Queues are not the right size");
         }
     }
 
     @Test
     @SuppressWarnings("unchecked")
     public void testFullQueueSerialization() throws IOException, ClassNotFoundException {
         final Queue<E> queue = makeFullCollection();
         final int size = getFullElements().length;
         if (!(queue instanceof Serializable && isTestSerialization())) {
             return;
         }
 
         final byte[] object = writeExternalFormToBytes((Serializable) queue);
         final Queue<E> queue2 = (Queue<E>) readExternalFormFromBytes(object);
 
         assertEquals(size, queue.size(), "Both queues are same size");
         assertEquals(size, queue2.size(), "Both queues are same size");
     }
 
     /**
      *  Tests {@link Queue#element()}.
      */
     @Test
     public void testQueueElement() {
         resetEmpty();
 
         assertThrows(NoSuchElementException.class, () -> getCollection().element(),
                 "Queue.element should throw NoSuchElementException");
 
         resetFull();
 
         assertTrue(getConfirmed().contains(getCollection().element()));
 
         if (!isRemoveSupported()) {
             return;
         }
 
         final int max = getFullElements().length;
         for (int i = 0; i < max; i++) {
             final E element = getCollection().element();
 
             if (!isNullSupported()) {
                 assertNotNull(element);
             }
 
             assertTrue(getConfirmed().contains(element));
 
             getCollection().remove(element);
             getConfirmed().remove(element);
 
             verify();
         }
 
         assertThrows(NoSuchElementException.class, () -> getCollection().element(),
                 "Queue.element should throw NoSuchElementException");
     }
 
     /**
      *  Tests {@link Queue#offer(Object)}.
      */
     @Test
     public void testQueueOffer() {
         if (!isAddSupported()) {
             return;
         }
 
         final E[] elements = getFullElements();
         for (final E element : elements) {
             resetEmpty();
             final boolean r = getCollection().offer(element);
             getConfirmed().add(element);
             verify();
             assertTrue(r, "Empty queue changed after add");
             assertEquals(1, getCollection().size(), "Queue size is 1 after first add");
         }
 
         resetEmpty();
         int size = 0;
         for (final E element : elements) {
             final boolean r = getCollection().offer(element);
             getConfirmed().add(element);
             verify();
             if (r) {
                 size++;
             }
             assertEquals(size, getCollection().size(), "Queue size should grow after add");
             assertTrue(getCollection().contains(element), "Queue should contain added element");
         }
     }
 
     /**
      *  Tests {@link Queue#peek()}.
      */
     @Test
     public void testQueuePeek() {
         if (!isRemoveSupported()) {
             return;
         }
 
         resetEmpty();
 
         E element = getCollection().peek();
         assertNull(element);
 
         resetFull();
 
         final int max = getFullElements().length;
         for (int i = 0; i < max; i++) {
             element = getCollection().peek();
 
             if (!isNullSupported()) {
                 assertNotNull(element);
             }
 
             assertTrue(getConfirmed().contains(element));
 
             getCollection().remove(element);
             getConfirmed().remove(element);
 
             verify();
         }
 
         element = getCollection().peek();
         assertNull(element);
     }
 
     /**
      *  Tests {@link Queue#poll()}.
      */
     @Test
     public void testQueuePoll() {
         if (!isRemoveSupported()) {
             return;
         }
 
         resetEmpty();
 
         E element = getCollection().poll();
         assertNull(element);
 
         resetFull();
 
         final int max = getFullElements().length;
         for (int i = 0; i < max; i++) {
             element = getCollection().poll();
             final boolean success = getConfirmed().remove(element);
             assertTrue(success, "poll should return correct element");
             verify();
         }
 
         element = getCollection().poll();
         assertNull(element);
     }
 
     /**
      *  Tests {@link Queue#remove()}.
      */
     @Test
     public void testQueueRemove() {
         if (!isRemoveSupported()) {
             return;
         }
 
         resetEmpty();
 
         assertThrows(NoSuchElementException.class, () -> getCollection().remove(),
                 "Queue.remove should throw NoSuchElementException");
 
         resetFull();
 
         final int max = getFullElements().length;
         for (int i = 0; i < max; i++) {
             final E element = getCollection().remove();
             final boolean success = getConfirmed().remove(element);
             assertTrue(success, "remove should return correct element");
             verify();
         }
 
         assertThrows(NoSuchElementException.class, () -> getCollection().element(),
                 "Queue.remove should throw NoSuchElementException");
     }
 
     /**
      *  Verifies that the test queue implementation matches the confirmed queue
      *  implementation.
      */
     @Override
     public void verify() {
         super.verify();
         final Iterator<E> iterator1 = getCollection().iterator();
         for (final E e : getConfirmed()) {
             assertTrue(iterator1.hasNext());
             final Object o1 = iterator1.next();
             final Object o2 = e;
             assertEquals(o1, o2);
         }
     }
 
 }