/*
    * 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.jexl3.internal.introspection;
  
  import java.lang.reflect.Array;
  import java.util.AbstractList;
  import java.util.Iterator;
  import java.util.RandomAccess;
  
  /**
   * A class that wraps an array within an AbstractList.
   * <p>
   * It overrides some methods because introspection uses this class a marker for wrapped arrays; the declared class
   * for these method is thus ArrayListWrapper.
   * The methods are get/set/size/contains and indexOf because it is used by contains.
   * </p>
   */
  public class ArrayListWrapper extends AbstractList<Object> implements RandomAccess {
      /** the array to wrap. */
      private final Object array;
  
      /**
       * Create the wrapper.
       * @param anArray {@link #array}
       */
      public ArrayListWrapper(final Object anArray) {
          if (!anArray.getClass().isArray()) {
              throw new IllegalArgumentException(anArray.getClass() + " is not an array");
          }
          this.array = anArray;
      }
  
      @Override
      public Object get(final int index) {
          return Array.get(array, index);
      }
  
      @Override
      public Object set(final int index, final Object element) {
          final Object old = Array.get(array, index);
          Array.set(array, index, element);
          return old;
      }
  
      @Override
      public int size() {
          return Array.getLength(array);
      }
  
      @Override
      public int indexOf(final Object o) {
          final int size = size();
          if (o == null) {
              for (int i = 0; i < size; i++) {
                  if (get(i) == null) {
                      return i;
                  }
              }
          } else {
              for (int i = 0; i < size; i++) {
                  if (o.equals(get(i))) {
                      return i;
                  }
              }
          }
          return -1;
      }
  
      @Override
      public boolean contains(final Object o) {
          return indexOf(o) != -1;
      }
      @Override
      public Iterator<Object> iterator() { return new ArrayIterator(array); }
  }