/*

 * 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.functors;

import java.io.Serializable;

import org.apache.commons.collections4.FunctorException;

import org.apache.commons.collections4.Predicate;

/**

 * Predicate implementation that throws an exception if the input is null.

 *

 * @since 3.0

 */

public final class NullIsExceptionPredicate<T> implements PredicateDecorator<T>, Serializable {

    /** Serial version UID */

    private static final long serialVersionUID = 3243449850504576071L;

    /** The predicate to decorate */

    private final Predicate<? super T> iPredicate;

    /**

     * Factory to create the null exception predicate.

     *

     * @param <T> the type that the predicate queries

     * @param predicate  the predicate to decorate, not null

     * @return the predicate

     * @throws NullPointerException if the predicate is null

     */

    public static <T> Predicate<T> nullIsExceptionPredicate(final Predicate<? super T> predicate) {

        if (predicate == null) {

            throw new NullPointerException("Predicate must not be null");

        }

        return new NullIsExceptionPredicate<>(predicate);

    }

    /**

     * Constructor that performs no validation.

     * Use <code>nullIsExceptionPredicate</code> if you want that.

     *

     * @param predicate  the predicate to call after the null check

     */

    public NullIsExceptionPredicate(final Predicate<? super T> predicate) {

        super();

        iPredicate = predicate;

    }

    /**

     * Evaluates the predicate returning the result of the decorated predicate

     * once a null check is performed.

     *

     * @param object  the input object

     * @return true if decorated predicate returns true

     * @throws FunctorException if input is null

     */

    @Override

    public boolean evaluate(final T object) {

        if (object == null) {

            throw new FunctorException("Input Object must not be null");

        }

        return iPredicate.evaluate(object);

    }

    /**

     * Gets the predicate being decorated.

     *

     * @return the predicate as the only element in an array

     * @since 3.1

     */

    @Override

    @SuppressWarnings("unchecked")

    public Predicate<? super T>[] getPredicates() {

        return new Predicate[] { iPredicate };

    }

}