/*

 * 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.multiset;

import java.util.Set;

import org.apache.commons.collections4.MultiSet;

import org.apache.commons.collections4.Predicate;

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

/**

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

 * match a specified predicate.

 * <p>

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

 * It is normally created to decorate an empty multiset.

 * If an object cannot be added to the multiset, an {@link IllegalArgumentException}

 * is thrown.

 * </p>

 * <p>

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

 * </p>

 * <pre>

 * MultiSet<E> set =

 *      PredicatedMultiSet.predicatedMultiSet(new HashMultiSet<E>(),

 *                                            NotNullPredicate.notNullPredicate());

 * </pre>

 *

 * @param <E> the type held in the multiset

 * @since 4.1

 */

public class PredicatedMultiSet<E> extends PredicatedCollection<E> implements MultiSet<E> {

    /** Serialization version */

    private static final long serialVersionUID = 20150629L;

    /**

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

     * <p>

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

     * are validated.

     *

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

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

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

     * @return a new predicated MultiSet

     * @throws NullPointerException if multiset or predicate is null

     * @throws IllegalArgumentException if the multiset contains invalid elements

     */

    public static <E> PredicatedMultiSet<E> predicatedMultiSet(final MultiSet<E> multiset,

                                                               final Predicate<? super E> predicate) {

        return new PredicatedMultiSet<>(multiset, predicate);

    }

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

    /**

     * Constructor that wraps (not copies).

     * <p>

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

     * are validated.

     *

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

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

     * @throws NullPointerException if multiset or predicate is null

     * @throws IllegalArgumentException if the multiset contains invalid elements

     */

    protected PredicatedMultiSet(final MultiSet<E> multiset, final Predicate<? super E> predicate) {

        super(multiset, predicate);

    }

    /**

     * Gets the decorated multiset.

     *

     * @return the decorated multiset

     */

    @Override

    protected MultiSet<E> decorated() {

        return (MultiSet<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 int add(final E object, final int count) {

        validate(object);

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

    }

    @Override

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

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

    }

    @Override

    public int getCount(final Object object) {

        return decorated().getCount(object);

    }

    @Override

    public int setCount(final E object, final int count) {

        validate(object);

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

    }

    @Override

    public Set<E> uniqueSet() {

        return decorated().uniqueSet();

    }

    @Override

    public Set<MultiSet.Entry<E>> entrySet() {

        return decorated().entrySet();

    }

}