/*

 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.util.logging;

import java.util.Enumeration;

import java.util.List;

import java.util.ArrayList;

/**

 * Logging is the implementation class of LoggingMXBean.

 *

 * The {@code LoggingMXBean} interface provides a standard

 * method for management access to the individual

 * {@code Logger} objects available at runtime.

 *

 * @author Ron Mann

 * @author Mandy Chung

 * @since 1.5

 *

 * @see javax.management

 * @see Logger

 * @see LogManager

 */

@SuppressWarnings("deprecation") // implements LoggingMXBean

final class Logging implements LoggingMXBean {

    private static LogManager logManager = LogManager.getLogManager();

    /** Constructor of Logging which is the implementation class

     *  of LoggingMXBean.

     */

    private Logging() {

    }

    @Override

    public List<String> getLoggerNames() {

        Enumeration<String> loggers = logManager.getLoggerNames();

        ArrayList<String> array = new ArrayList<>();

        for (; loggers.hasMoreElements();) {

            array.add(loggers.nextElement());

        }

        return array;

    }

    private static String EMPTY_STRING = "";

    @Override

    public String getLoggerLevel(String loggerName) {

        Logger l = logManager.getLogger(loggerName);

        if (l == null) {

            return null;

        }

        Level level = l.getLevel();

        if (level == null) {

            return EMPTY_STRING;

        } else {

            return level.getLevelName();

        }

    }

    @Override

    public void setLoggerLevel(String loggerName, String levelName) {

        if (loggerName == null) {

            throw new NullPointerException("loggerName is null");

        }

        Logger logger = logManager.getLogger(loggerName);

        if (logger == null) {

            throw new IllegalArgumentException("Logger " + loggerName +

                " does not exist");

        }

        Level level = null;

        if (levelName != null) {

            // parse will throw IAE if logLevel is invalid

            level = Level.findLevel(levelName);

            if (level == null) {

                throw new IllegalArgumentException("Unknown level \"" + levelName + "\"");

            }

        }

        logger.setLevel(level);

    }

    @Override

    public String getParentLoggerName( String loggerName ) {

        Logger l = logManager.getLogger( loggerName );

        if (l == null) {

            return null;

        }

        Logger p = l.getParent();

        if (p == null) {

            // root logger

            return EMPTY_STRING;

        } else {

            return p.getName();

        }

    }

    static Logging getInstance() {

        return INSTANCE;

    }

    private static final Logging INSTANCE = new Logging();

}