/*

 * 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.bag;

import java.util.Set;

import org.apache.commons.collections4.Bag;

import org.apache.commons.collections4.Predicate;

import org.apache.commons.collections4.collection.PredicatedCollection;

/**

 * Decorates another {@link Bag} to validate that additions

 * match a specified predicate.

 * <p>

 * This bag exists to provide validation for the decorated bag.

 * It is normally created to decorate an empty bag.

 * If an object cannot be added to the bag, an {@link IllegalArgumentException} is thrown.

 * </p>

 * <p>

 * One usage would be to ensure that no null entries are added to the bag.

 * </p>

 * <pre>

 * Bag bag = PredicatedBag.predicatedBag(new HashBag(), NotNullPredicate.INSTANCE);

 * </pre>

 * <p>

 * This class is Serializable from Commons Collections 3.1.

 * </p>

 *

 * @param <E> the type of elements in this bag

 * @since 3.0

 */

public class PredicatedBag<E> extends PredicatedCollection<E> implements Bag<E> {

    /** Serialization version */

    private static final long serialVersionUID = -2575833140344736876L;

    /**

     * Factory method to create a predicated (validating) bag.

     * <p>

     * If there are any elements already in the bag being decorated, they

     * are validated.

     *

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

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

     * @param predicate  the predicate to use for validation, must not be null

     * @return a new predicated Bag

     * @throws NullPointerException if bag or predicate is null

     * @throws IllegalArgumentException if the bag contains invalid elements

     * @since 4.0

     */

    public static <E> PredicatedBag<E> predicatedBag(final Bag<E> bag, final Predicate<? super E> predicate) {

        return new PredicatedBag<>(bag, predicate);

    }

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

    /**

     * Constructor that wraps (not copies).

     * <p>

     * If there are any elements already in the bag being decorated, they

     * are validated.

     *

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

     * @param predicate  the predicate to use for validation, must not be null

     * @throws NullPointerException if bag or predicate is null

     * @throws IllegalArgumentException if the bag contains invalid elements

     */

    protected PredicatedBag(final Bag<E> bag, final Predicate<? super E> predicate) {

        super(bag, predicate);

    }

    /**

     * Gets the decorated bag.

     *

     * @return the decorated bag

     */

    @Override

    protected Bag<E> decorated() {

        return (Bag<E>) super.decorated();

    }

    @Override

    public boolean equals(final Object object) {

        return object == this || decorated().equals(object);

    }

    @Override

    public int hashCode() {

        return decorated().hashCode();

    }

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

    @Override

    public boolean add(final E object, final int count) {

        validate(object);

        return decorated().add(object, count);

    }

    @Override

    public boolean remove(final Object object, final int count) {

        return decorated().remove(object, count);

    }

    @Override

    public Set<E> uniqueSet() {

        return decorated().uniqueSet();

    }

    @Override

    public int getCount(final Object object) {

        return decorated().getCount(object);

    }

}