/*
 * Copyright (C) 2013 University of Dundee & Open Microscopy Environment.
 * All rights reserved.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package ome.services.blitz.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Test under which platform OMERO is currently running.
 * Exactly one of the public methods returns <code>true</code>. Each executes quickly.
 * Useful with {@literal @}Assumption annotations to limit unit tests to specific test platforms.
 *
 * @author m.t.b.carroll@dundee.ac.uk
 * @since 5.0
 */

public class CurrentPlatform {
    /**
     * A enumeration of operating systems under which OMERO may run.
     * 
     * @author m.t.b.carroll@dundee.ac.uk
     * @since 5.0
     */
    private enum OperatingSystem {
        WINDOWS("Microsoft Windows"),
        LINUX("Linux"),
        MAC("Apple Mac OS X");

        private final String name;

        OperatingSystem(String name) {
            this.name = name;
        }
    
        @Override
        public String toString() {
            return this.name;
        }
    }

    /* the current platform's operating system */
    private static final OperatingSystem os;

    static {
        final Logger logger = LoggerFactory.getLogger(CurrentPlatform.class);

        final String osName = System.getProperty("os.name");
        if (osName.startsWith("Windows "))
            os = OperatingSystem.WINDOWS;
        else if (osName.equals("Linux"))
            os = OperatingSystem.LINUX;
        else if (osName.equals("Mac OS X"))
            os = OperatingSystem.MAC;
        else {
            os = null;
            logger.warn("failed to recognize current operating system");
        }
        if (os != null && logger.isDebugEnabled()) {
            logger.debug("recognized current operating system as being " + os);
        }
    }

    /**
     * @return if this platform is Microsoft Windows
     */
    public static boolean isWindows() {
        return os == OperatingSystem.WINDOWS;
    }

    /**
     * @return if this platform is Linux
     */
    public static boolean isLinux() {
        return os == OperatingSystem.LINUX;
    }

    /**
     * @return if this platform is Mac OS X
     */
    public static boolean isMacOSX() {
        return os == OperatingSystem.MAC;
    }

    /**
     * @return if this platform is unidentified
     */
    public static boolean isUnknown() {
        return os == null;
    }
}