content: /*
   * Copyright (c) 2020 Adam Gaj
   *
   * 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
   *
   *     https://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.adgadev.jplusone.asserts.impl.util;
  
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Objects;
  
  import static java.util.Collections.emptyList;
  
  public class CollectionUtils {
  
      public static <T> T getLastElement(Collection<T> collection) {
          return collection.stream()
                  .skip(Math.max(collection.size() - 1, 0))
                  .findFirst()
                  .orElse(null);
      }
  
      public static <T> List<T> getMaxCommonHeadFragmentOfLists(List<T> firstList, List<T> secondList) {
          Iterator<T> firstIterator = firstList.iterator();
          Iterator<T> secondIterator = secondList.iterator();
          int amountOfSameItems = 0;
          boolean differenceFound = false;
  
          while (firstIterator.hasNext() && secondIterator.hasNext() && !differenceFound) {
              T firstListItem = firstIterator.next();
              T secondListItem = secondIterator.next();
  
              if (Objects.equals(firstListItem, secondListItem)) {
                  amountOfSameItems++;
              } else {
                  differenceFound = true;
              }
          }
  
          return amountOfSameItems == 0 ? emptyList() : firstList.subList(0, amountOfSameItems);
      }
  }
  