/*
    * 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.jexl2.internal;
  
  import java.lang.reflect.Array;
  import java.util.AbstractList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.ListIterator;
  
  /**
   * A class that wraps an array within an AbstractList.
   * <p>
   * It overrides all methods because introspection uses this class a a marker for wrapped arrays; the declared class
   * for any method is thus always ArrayListWrapper.
   * </p>
   */
  public class ArrayListWrapper extends AbstractList<Object> {
      /** the array to wrap. */
      private final Object array;
  
      /**
       * Create the wrapper.
       * @param anArray {@link #array}
       */
      public ArrayListWrapper(Object anArray) {
          if (!anArray.getClass().isArray()) {
              throw new IllegalArgumentException(anArray.getClass() + " is not an array");
          }
          this.array = anArray;
      }
  
      /** {@inheritDoc} */
      @Override
      public Object get(int index) {
          return Array.get(array, index);
      }
  
      /** {@inheritDoc} */
      @Override
      public Object set(int index, Object element) {
          Object old = get(index);
          Array.set(array, index, element);
          return old;
      }
  
      /** {@inheritDoc} */
      @Override
      public int size() {
          return Array.getLength(array);
      }
  
      @Override
      public Object[] toArray() {
          final int size = size();
          Object[] a = new Object[size];
          for(int i = 0; i < size; ++i) {
              a[i] = get(i);
          }
          return a;
      }
  
      @Override
      @SuppressWarnings("unchecked")
      public <T> T[] toArray(T[] a) {
          int size = size();
          if (a.length < size) {
              T[] x = (T[]) Array.newInstance(a.getClass().getComponentType(), size);
              System.arraycopy(a, a.length, x, 0, a.length);
          }
          for(int i = 0; i < size; ++i) {
              a[i] = (T) get(i);
          }
          if (a.length > size) {
              a[size] = null;
          }
          return a;
      }
  
      @Override
      public int indexOf(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(Object o) {
         return indexOf(o) != -1;
     }
     
     @Override
     public boolean isEmpty() {
         return super.isEmpty();
     }
 
     @Override
     public Iterator<Object> iterator() {
         return super.iterator();
     }
     
     @Override
     public boolean containsAll(Collection<?> c) {
         return super.containsAll(c);
     }
 
     @Override
     public int lastIndexOf(Object o) {
         return super.lastIndexOf(o);
     }
 
     @Override
     public ListIterator<Object> listIterator() {
         return super.listIterator();
     }
 
     @Override
     public ListIterator<Object> listIterator(int index) {
         return super.listIterator(index);
     }
 
     @Override
     public List<Object> subList(int fromIndex, int toIndex) {
         return super.subList(fromIndex, toIndex);
     }
     
     @Override
     public boolean add(Object o) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public boolean remove(Object o) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public boolean addAll(Collection<? extends Object> c) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public boolean addAll(int index, Collection<? extends Object> c) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public boolean removeAll(Collection<?> c) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public boolean retainAll(Collection<?> c) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public void clear() {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public void add(int index, Object element) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
     @Override
     public Object remove(int index) {
         throw new UnsupportedOperationException("Not supported.");
     }
 
 }