/*
    * 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.iterators;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertSame;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.util.ArrayList;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.NoSuchElementException;
  import java.util.Set;
  
  import org.apache.commons.collections4.OrderedMapIterator;
  import org.junit.jupiter.api.Test;
  
  /**
   * Abstract class for testing the OrderedMapIterator interface.
   * <p>
   * This class provides a framework for testing an implementation of MapIterator.
   * Concrete subclasses must provide the list iterator to be tested.
   * They must also specify certain details of how the list iterator operates by
   * overriding the supportsXxx() methods if necessary.
   *
   * @param <K> the type of the keys in the maps tested.
   * @param <V> the type of the values in the maps tested.
   */
  public abstract class AbstractOrderedMapIteratorTest<K, V> extends AbstractMapIteratorTest<K, V> {
  
      @Override
      public abstract OrderedMapIterator<K, V> makeEmptyIterator();
  
      @Override
      public abstract OrderedMapIterator<K, V> makeObject();
  
      /**
       * Test that the empty list iterator contract is correct.
       */
      @Test
      @Override
      public void testEmptyMapIterator() {
          if (!supportsEmptyIterator()) {
              return;
          }
  
          super.testEmptyMapIterator();
  
          final OrderedMapIterator<K, V> it = makeEmptyIterator();
          assertFalse(it.hasPrevious());
  
          assertThrows(NoSuchElementException.class, () -> it.previous());
      }
  
      /**
       * Test that the full list iterator contract is correct.
       */
      @Test
      @Override
      public void testFullMapIterator() {
          if (!supportsFullIterator()) {
              return;
          }
  
          super.testFullMapIterator();
  
          final OrderedMapIterator<K, V> it = makeObject();
          final Map<K, V> map = getMap();
  
          assertTrue(it.hasNext());
          assertFalse(it.hasPrevious());
          final Set<K> set = new HashSet<>();
          while (it.hasNext()) {
              // getKey
              final K key = it.next();
              assertSame(key, it.getKey(), "it.next() should equals getKey()");
              assertTrue(map.containsKey(key),  "Key must be in map");
              assertTrue(set.add(key), "Key must be unique");
  
              // getValue
              final V value = it.getValue();
             if (!isGetStructuralModify()) {
                 assertSame(map.get(key), value, "Value must be mapped to key");
             }
             assertTrue(map.containsValue(value),  "Value must be in map");
 
             assertTrue(it.hasPrevious());
 
             verify();
         }
         while (it.hasPrevious()) {
             // getKey
             final Object key = it.previous();
             assertSame(key, it.getKey(), "it.previous() should equals getKey()");
             assertTrue(map.containsKey(key),  "Key must be in map");
             assertTrue(set.remove(key), "Key must be unique");
 
             // getValue
             final Object value = it.getValue();
             if (!isGetStructuralModify()) {
                 assertSame(map.get(key), value, "Value must be mapped to key");
             }
             assertTrue(map.containsValue(value),  "Value must be in map");
 
             assertTrue(it.hasNext());
 
             verify();
         }
     }
 
     /**
      * Test that the iterator order matches the keySet order.
      */
     @Test
     public void testMapIteratorOrder() {
         if (!supportsFullIterator()) {
             return;
         }
 
         final OrderedMapIterator<K, V> it = makeObject();
         final Map<K, V> map = getMap();
 
         assertEquals(new ArrayList<>(map.keySet()), new ArrayList<>(map.keySet()), "keySet() not consistent");
 
         final Iterator<K> it2 = map.keySet().iterator();
         assertTrue(it.hasNext());
         assertTrue(it2.hasNext());
         final List<K> list = new ArrayList<>();
         while (it.hasNext()) {
             final K key = it.next();
             assertEquals(it2.next(), key);
             list.add(key);
         }
         assertEquals(map.size(), list.size());
         while (it.hasPrevious()) {
             final K key = it.previous();
             assertEquals(list.get(list.size() - 1), key);
             list.remove(list.size() - 1);
         }
         assertEquals(0, list.size());
     }
 
 }