/*

 * 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.Iterator;

import java.util.List;

import java.util.ListIterator;

import java.util.function.Predicate;

import org.apache.commons.collections4.Unmodifiable;

import org.apache.commons.collections4.iterators.UnmodifiableIterator;

import org.apache.commons.collections4.iterators.UnmodifiableListIterator;

/**

 * Decorates another <code>List</code> to ensure it can't be altered.

 * <p>

 * This class is Serializable from Commons Collections 3.1.

 * </p>

 * <p>

 * Attempts to modify it will result in an UnsupportedOperationException.

 * </p>

 *

 * @since 3.0

 */

public final class UnmodifiableList<E>

        extends AbstractSerializableListDecorator<E>

        implements Unmodifiable {

    /** Serialization version */

    private static final long serialVersionUID = 6595182819922443652L;

    /**

     * Factory method to create an unmodifiable list.

     *

     * @param <E> the type of the elements in the list

     * @param list  the list to decorate, must not be null

     * @return a new unmodifiable list

     * @throws NullPointerException if list is null

     * @since 4.0

     */

    public static <E> List<E> unmodifiableList(final List<? extends E> list) {

        if (list instanceof Unmodifiable) {

            @SuppressWarnings("unchecked") // safe to upcast

            final List<E> tmpList = (List<E>) list;

            return tmpList;

        }

        return new UnmodifiableList<>(list);

    }

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

    /**

     * Constructor that wraps (not copies).

     *

     * @param list  the list to decorate, must not be null

     * @throws NullPointerException if list is null

     */

    @SuppressWarnings("unchecked") // safe to upcast

    public UnmodifiableList(final List<? extends E> list) {

        super((List<E>) list);

    }

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

    @Override

    public Iterator<E> iterator() {

        return UnmodifiableIterator.unmodifiableIterator(decorated().iterator());

    }

    @Override

    public boolean add(final Object object) {

        throw new UnsupportedOperationException();

    }

    @Override

    public boolean addAll(final Collection<? extends E> coll) {

        throw new UnsupportedOperationException();

    }

    @Override

    public void clear() {

        throw new UnsupportedOperationException();

    }

    @Override

    public boolean remove(final Object object) {

        throw new UnsupportedOperationException();

    }

    /**

     * @since 4.4

     */

    @Override

    public boolean removeIf(Predicate<? super E> filter) {

        throw new UnsupportedOperationException();

    }

    @Override

    public boolean removeAll(final Collection<?> coll) {

        throw new UnsupportedOperationException();

    }

    @Override

    public boolean retainAll(final Collection<?> coll) {

        throw new UnsupportedOperationException();

    }

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

    @Override

    public ListIterator<E> listIterator() {

        return UnmodifiableListIterator.umodifiableListIterator(decorated().listIterator());

    }

    @Override

    public ListIterator<E> listIterator(final int index) {

        return UnmodifiableListIterator.umodifiableListIterator(decorated().listIterator(index));

    }

    @Override

    public void add(final int index, final E object) {

        throw new UnsupportedOperationException();

    }

    @Override

    public boolean addAll(final int index, final Collection<? extends E> coll) {

        throw new UnsupportedOperationException();

    }

    @Override

    public E remove(final int index) {

        throw new UnsupportedOperationException();

    }

    @Override

    public E set(final int index, final E object) {

        throw new UnsupportedOperationException();

    }

    @Override

    public List<E> subList(final int fromIndex, final int toIndex) {

        final List<E> sub = decorated().subList(fromIndex, toIndex);

        return new UnmodifiableList<>(sub);

    }

}