/***** BEGIN LICENSE BLOCK *****
 * Version: CPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Common Public
 * License Version 1.0 (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.eclipse.org/legal/cpl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2008 JRuby project
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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package org.jruby.platform;

import org.jruby.util.SafePropertyAccessor;

import java.nio.ByteOrder;
import java.util.HashMap;
import java.util.Map;

/**
 * Platform specific constants.
 */
public class Platform {
    private static final Platform INSTANCE = new Platform();
    public static Platform getPlatform() {
        return INSTANCE;
    }
    protected Platform() {
    }

    public static void main(String[] args) {
        System.out.println(System.getProperties());
    }

    public String getPackageName() {
        return String.format("%s.%s.%s", Platform.class.getPackage().getName(), OS, ARCH);
    }
    public String getOSPackageName() {
        return String.format("%s.%s", Platform.class.getPackage().getName(), OS);
    }
    
    private static final String DARWIN = "darwin";
    private static final String WINDOWS = "windows";
    private static final String LINUX = "linux";
    private static final String FREEBSD = "freebsd";
    private static final String OPENBSD = "openbsd";
    private static final String SOLARIS = "solaris";
    private static final String OPENVMS = "openvms";

    private static final String GCJ = "GNU libgcj";
    private static final String IBM = "IBM J9 VM";

    public static final Map<String, String> OS_NAMES = new HashMap<String, String>() {{
        put("Mac OS X", DARWIN);
    }};
    public static final Map<String, String> ARCH_NAMES = new HashMap<String, String>() {{
        put("x86", "i386");
    }};
    private static String initOperatingSystem() {
        String osname = getProperty("os.name", "unknown").toLowerCase();
        for (String s : OS_NAMES.keySet()) {
            if (s.equalsIgnoreCase(osname)) {
                return OS_NAMES.get(s);
            }
        }
        if (osname.startsWith("windows")) {
            return WINDOWS;
        }
        return osname;
    }
    private static String initArchitecture() {
        String arch = getProperty("os.arch", "unknown").toLowerCase();
        for (String s : ARCH_NAMES.keySet()) {
            if (s.equalsIgnoreCase(arch)) {
                return ARCH_NAMES.get(s);
            }
        }
        if ("universal".equals(arch)) {
            // OS X OpenJDK7 builds report "universal" right now
            String bits = SafePropertyAccessor.getProperty("sun.arch.data.model");
            if ("32".equals(bits)) {
                System.setProperty("os.arch", "i386");
                arch = "i386";
            } else if ("64".equals(bits)) {
                System.setProperty("os.arch", "x86_64");
                arch = "x86_64";
            }
        }
        return arch;
    }
    public static final String ARCH = initArchitecture();
    public static final String OS = initOperatingSystem();
    public static final String JVM = getProperty("java.vm.name", "unknown");

    public static final boolean IS_WINDOWS = OS.equals(WINDOWS);

    public static final boolean IS_MAC = OS.equals(DARWIN);
    public static final boolean IS_FREEBSD = OS.equals(FREEBSD);
    public static final boolean IS_OPENBSD = OS.equals(OPENBSD);
    public static final boolean IS_LINUX = OS.equals(LINUX);
    public static final boolean IS_SOLARIS = OS.equals(SOLARIS);
    public static final boolean IS_BSD = IS_MAC || IS_FREEBSD || IS_OPENBSD;
    public static final boolean IS_OPENVMS = OS.equals(OPENVMS);
    public static final String NAME = String.format("%s-%s", ARCH, OS);
    public static final int BIG_ENDIAN = 4321;
    public static final int LITTLE_ENDIAN = 1234;
    public static final int BYTE_ORDER = ByteOrder.nativeOrder().equals(ByteOrder.BIG_ENDIAN) ? BIG_ENDIAN : LITTLE_ENDIAN;

    public static final boolean IS_GCJ = JVM.equals(GCJ);
    public static final boolean IS_IBM = JVM.equals(IBM);
    
    /**
     * An extension over <code>System.getProperty</code> method.
     * Handles security restrictions, and returns the default
     * value if the access to the property is restricted.
     * @param property The system property name.
     * @param defValue The default value.
     * @return The value of the system property,
     *         or the default value.
     */
    public static String getProperty(String property, String defValue) {
        try {
            return System.getProperty(property, defValue);
        } catch (SecurityException se) {
            return defValue;
        }
    }
}
