/**

 * Free Telco Dictionary

 * Copyright © 2013 František Kučera (frantovo.cz)

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 3 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

package cz.frantovo.telco.dictionary;

import java.io.Closeable;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

/**

 * Common functions

 * 

 * @author Ing. František Kučera (frantovo.cz)

 */

public class Functions {

	private static final Logger log = Logger.getLogger(Functions.class.getName());

	public static Iterable<Node> nodeIterable(final NodeList list) {

		return new Iterable<Node>() {

			@Override

			public Iterator<Node> iterator() {

				return new Iterator<Node>() {

					int position;

					@Override

					public boolean hasNext() {

						return position < list.getLength();

					}

					@Override

					public Node next() {

						return list.item(position++);

					}

					@Override

					public void remove() {

						throw new UnsupportedOperationException("remove not supported");

					}

				};

			}

		};

	}

	public static void close(Closeable c) {

		try {

			c.close();

		} catch (Exception e) {

			log.log(Level.WARNING, "closing of " + c + " has failed", e);

		}

	}

	public static boolean equalz(Object a, Object b) {

		return a == null ? b == null : a.equals(b);

	}

	public static <K, V> Set<K> getKeysForValue(Map<K, V> map, V value) {

		Set<K> keysFound = new HashSet<>();

		for (Entry<K, V> entry : map.entrySet()) {

			if (equalz(value, entry.getValue())) {

				keysFound.add(entry.getKey());

			}

		}

		return keysFound;

	}

	private Functions() {

	}

}