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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2017 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed 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.wildfly.naming.client;

import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;

import javax.naming.NamingEnumeration;
import javax.naming.NamingException;

import org.wildfly.common.Assert;

/**
 * A naming enumeration which works with {@code try}-with-resources.
 *
 * @author David M. Lloyd
 */
public interface CloseableNamingEnumeration extends NamingEnumeration, NamingCloseable {

    /**
     * Close the enumeration.
     *
     * @throws NamingException if closing the enumeration failed for some reason
     */
    void close() throws NamingException;

    /**
     * Create a naming enumeration from an iterable collection.
     *
     * @param iterable the iterable
     * @param  the element type
     * @return the enumeration
     */
    static  CloseableNamingEnumeration fromIterable(Iterable iterable) {
        Assert.checkNotNullParam("iterable", iterable);
        return fromIterator(iterable.iterator());
    }

    /**
     * Create a naming enumeration from a collection iterator.
     *
     * @param iterator the iterator
     * @param  the element type
     * @return the enumeration
     */
    static  CloseableNamingEnumeration fromIterator(Iterator iterator) {
        Assert.checkNotNullParam("iterator", iterator);
        return new CloseableNamingEnumeration() {
            public T next() {
                return nextElement();
            }

            public boolean hasMore() {
                return hasMoreElements();
            }

            public void close() {
            }

            public boolean hasMoreElements() {
                return iterator.hasNext();
            }

            public T nextElement() {
                return iterator.next();
            }
        };
    }

    /**
     * Create a naming enumeration from a collection enumeration.
     *
     * @param enumeration the enumeration
     * @param  the element type
     * @return the enumeration
     */
    static  CloseableNamingEnumeration fromEnumeration(Enumeration enumeration) {
        Assert.checkNotNullParam("enumeration", enumeration);
        if (enumeration instanceof CloseableNamingEnumeration) {
            return (CloseableNamingEnumeration) enumeration;
        } else if (enumeration instanceof NamingEnumeration) {
            return fromEnumeration((NamingEnumeration) enumeration);
        }
        return new CloseableNamingEnumeration() {
            public T next() {
                return nextElement();
            }

            public boolean hasMore() {
                return hasMoreElements();
            }

            public void close() {
            }

            public boolean hasMoreElements() {
                return enumeration.hasMoreElements();
            }

            public T nextElement() {
                return enumeration.nextElement();
            }
        };
    }

    /**
     * Create a closeable naming enumeration from a naming enumeration.
     *
     * @param enumeration the enumeration
     * @param  the element type
     * @return the enumeration
     */
    static  CloseableNamingEnumeration fromEnumeration(NamingEnumeration enumeration) {
        Assert.checkNotNullParam("enumeration", enumeration);
        if (enumeration instanceof CloseableNamingEnumeration) {
            return (CloseableNamingEnumeration) enumeration;
        }
        return new CloseableNamingEnumeration() {
            public T next() throws NamingException {
                return enumeration.next();
            }

            public boolean hasMore() throws NamingException {
                return enumeration.hasMore();
            }

            public void close() throws NamingException {
                enumeration.close();
            }

            public boolean hasMoreElements() {
                return enumeration.hasMoreElements();
            }

            public T nextElement() {
                return enumeration.nextElement();
            }
        };
    }

    CloseableNamingEnumeration EMPTY = fromEnumeration(Collections.emptyEnumeration());

    @SuppressWarnings("unchecked")
    static  CloseableNamingEnumeration empty() {
        return (CloseableNamingEnumeration) EMPTY;
    }
}