/*
 * 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.list;

import java.util.Collection;
import java.util.List;
import java.util.ListIterator;

import org.apache.commons.collections4.Transformer;
import org.apache.commons.collections4.collection.TransformedCollection;
import org.apache.commons.collections4.iterators.AbstractListIteratorDecorator;

Decorates another List to transform objects that are added.

The add and set methods are affected by this class.
Thus objects must be removed or searched for using their transformed form.
For example, if the transformation converts Strings to Integers, you must
use the Integer form to remove objects.


This class is Serializable from Commons Collections 3.1.

Since:
3.0/**
 * Decorates another <code>List</code> to transform objects that are added.
 * <p>
 * The add and set methods are affected by this class.
 * Thus objects must be removed or searched for using their transformed form.
 * For example, if the transformation converts Strings to Integers, you must
 * use the Integer form to remove objects.
 * </p>
 * <p>
 * This class is Serializable from Commons Collections 3.1.
 * </p>
 *
 * @since 3.0
 */
public class TransformedList<E> extends TransformedCollection<E> implements List<E> {

    
Serialization version /** Serialization version */
    private static final long serialVersionUID = 1077193035000013141L;

    
Factory method to create a transforming list.
 If there are any elements already in the list being decorated, they are NOT transformed. Contrast this with transformedList(List<Object>, Transformer<? super Object,? extends Object>). 
Params:
list –  the list to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Type parameters:
<E> – the type of the elements in the list
Throws:
NullPointerException – if list or transformer is null
Returns:
a new transformed list
Since:
4.0/**
     * Factory method to create a transforming list.
     * <p>
     * If there are any elements already in the list being decorated, they
     * are NOT transformed.
     * Contrast this with {@link #transformedList(List, Transformer)}.
     *
     * @param <E> the type of the elements in the list
     * @param list  the list to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @return a new transformed list
     * @throws NullPointerException if list or transformer is null
     * @since 4.0
     */
    public static <E> TransformedList<E> transformingList(final List<E> list,
                                                          final Transformer<? super E, ? extends E> transformer) {
        return new TransformedList<>(list, transformer);
    }

    
Factory method to create a transforming list that will transform
existing contents of the specified list.
 If there are any elements already in the list being decorated, they will be transformed by this method. Contrast this with transformingList(List<Object>, Transformer<? super Object,? extends Object>). 
Params:
list –  the list to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Type parameters:
<E> – the type of the elements in the list
Throws:
NullPointerException – if list or transformer is null
Returns:
a new transformed List
Since:
4.0/**
     * Factory method to create a transforming list that will transform
     * existing contents of the specified list.
     * <p>
     * If there are any elements already in the list being decorated, they
     * will be transformed by this method.
     * Contrast this with {@link #transformingList(List, Transformer)}.
     *
     * @param <E> the type of the elements in the list
     * @param list  the list to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @return a new transformed List
     * @throws NullPointerException if list or transformer is null
     * @since 4.0
     */
    public static <E> TransformedList<E> transformedList(final List<E> list,
                                                         final Transformer<? super E, ? extends E> transformer) {
        final TransformedList<E> decorated = new TransformedList<>(list, transformer);
        if (list.size() > 0) {
            @SuppressWarnings("unchecked") // list is of type E
            final E[] values = (E[]) list.toArray(); // NOPMD - false positive for generics
            list.clear();
            for (final E value : values) {
                decorated.decorated().add(transformer.transform(value));
            }
        }
        return decorated;
    }

    //-----------------------------------------------------------------------
    
Constructor that wraps (not copies).

If there are any elements already in the list being decorated, they
are NOT transformed.
Params:
list –  the list to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Throws:
NullPointerException – if list or transformer is null/**
     * Constructor that wraps (not copies).
     * <p>
     * If there are any elements already in the list being decorated, they
     * are NOT transformed.
     *
     * @param list  the list to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @throws NullPointerException if list or transformer is null
     */
    protected TransformedList(final List<E> list, final Transformer<? super E, ? extends E> transformer) {
        super(list, transformer);
    }

    
Gets the decorated list.
Returns:
the decorated list/**
     * Gets the decorated list.
     *
     * @return the decorated list
     */
    protected List<E> getList() {
        return (List<E>) decorated();
    }

    @Override
    public boolean equals(final Object object) {
        return object == this || decorated().equals(object);
    }

    @Override
    public int hashCode() {
        return decorated().hashCode();
    }

    //-----------------------------------------------------------------------

    @Override
    public E get(final int index) {
        return getList().get(index);
    }

    @Override
    public int indexOf(final Object object) {
        return getList().indexOf(object);
    }

    @Override
    public int lastIndexOf(final Object object) {
        return getList().lastIndexOf(object);
    }

    @Override
    public E remove(final int index) {
        return getList().remove(index);
    }

    //-----------------------------------------------------------------------

    @Override
    public void add(final int index, E object) {
        object = transform(object);
        getList().add(index, object);
    }

    @Override
    public boolean addAll(final int index, Collection<? extends E> coll) {
        coll = transform(coll);
        return getList().addAll(index, coll);
    }

    @Override
    public ListIterator<E> listIterator() {
        return listIterator(0);
    }

    @Override
    public ListIterator<E> listIterator(final int i) {
        return new TransformedListIterator(getList().listIterator(i));
    }

    @Override
    public E set(final int index, E object) {
        object = transform(object);
        return getList().set(index, object);
    }

    @Override
    public List<E> subList(final int fromIndex, final int toIndex) {
        final List<E> sub = getList().subList(fromIndex, toIndex);
        return new TransformedList<>(sub, transformer);
    }

    
Inner class Iterator for the TransformedList
/**
     * Inner class Iterator for the TransformedList
     */
    protected class TransformedListIterator extends AbstractListIteratorDecorator<E> {

        
Create a new transformed list iterator.
Params:
iterator –  the list iterator to decorate/**
         * Create a new transformed list iterator.
         *
         * @param iterator  the list iterator to decorate
         */
        protected TransformedListIterator(final ListIterator<E> iterator) {
            super(iterator);
        }

        @Override
        public void add(E object) {
            object = transform(object);
            getListIterator().add(object);
        }

        @Override
        public void set(E object) {
            object = transform(object);
            getListIterator().set(object);
        }
    }

}