/*

 * 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 com.apple.jobjc;

import java.lang.reflect.Field;

import java.nio.ByteOrder;

import java.util.ArrayList;

import java.util.List;

import sun.misc.Unsafe;

public final class JObjCRuntime {

    static { System.loadLibrary("JObjC"); }

    public static enum Arch{ ppc, i386, x86_64 };

    public static enum Width{ W32, W64 };

    public static final Arch ARCH = getArch();

    public static final Width WIDTH = getWidth();

    private static Arch getArch(){

        String arch = System.getProperty("os.arch");

        if("ppc".equals(arch)) return Arch.ppc;

        if("i386".equals(arch)) return Arch.i386;

        if("x86_64".equals(arch)) return Arch.x86_64;

        if("amd64".equals(arch)) return Arch.x86_64;

        if("universal".equals(arch)) return Arch.x86_64;

        throw new RuntimeException("Did not recognize os.arch system property: '" + arch + "'");

    }

    private static Width getWidth(){

        String width = System.getProperty("sun.arch.data.model");

        if("32".equals(width)) return Width.W32;

        if("64".equals(width)) return Width.W64;

        throw new RuntimeException("Did not recognize sun.arch.data.model system property: '" + width + "'");

    }

    public static final boolean IS32 = System.getProperty("sun.arch.data.model").equals("32");

    public static final boolean IS64 = System.getProperty("sun.arch.data.model").equals("64");

    public static final int PTR_LEN = IS64 ? 8 : 4;

    public static final boolean IS_BIG_ENDIAN = ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN;

    static final boolean DEBUG = Boolean.parseBoolean(System.getProperty("JObjC.debug"));

    static void checkPermission(){

        final SecurityManager security = System.getSecurityManager();

        if (security != null) security.checkPermission(new RuntimePermission("canProcessApplicationEvents"));

    }

    public final void assertOK(){

        if(this != instance)

            throw new SecurityException("runtime");

    }

    private JObjCRuntime(){}

    private static JObjCRuntime instance;

    static JObjCRuntime inst() {

        if (instance == null) instance = new JObjCRuntime();

        return instance;

    }

    public static JObjCRuntime getInstance() {

        checkPermission();

        return inst();

    }

    public final NativeArgumentBuffer getThreadLocalState() {

        return NativeArgumentBuffer.getThreadLocalBuffer(this);

    }

    final Unsafe unsafe = getUnsafe();

    final Subclassing subclassing = new Subclassing(this);

    final List<String> registeredPackages = new ArrayList<String>();

    @SuppressWarnings("unchecked")

    Class<? extends ID> getClassForNativeClassName(final String className) {

        for (final String pkg : registeredPackages) {

            try {

                final Class<?> clazz = Class.forName(pkg + "." + className);

                if (clazz != null) return (Class<? extends ID>)clazz;

            } catch (final ClassNotFoundException e) { }

        }

        return null;

    }

    private final static Unsafe getUnsafe() {

        Unsafe inst = null;

        try {

            Field f = Unsafe.class.getDeclaredField("theUnsafe");

            f.setAccessible(true);

            inst = (Unsafe) f.get(null);

            if(inst == null) throw new NullPointerException("Unsafe.theUnsafe == null");

        } catch (Exception e) {

            throw new RuntimeException("Unable to get instance of Unsafe.", e);

        }

        return inst;

    }

    public void registerPackage(final String pkg) {

        registeredPackages.add(pkg);

    }

    /**

     * Register a subclass of NSObject to allow the native side to send

     * messages which in turn call java methods declared on the class.

     * If a native class by the same name already exists, registerClass

     * will simply return without doing anything.

     *

     * For a usage example, see the SubclassingTest.

     */

    public boolean registerUserClass(Class<? extends ID> clazz, Class<? extends NSClass> clazzClazz) {

        return subclassing.registerUserClass(clazz, clazzClazz);

    }

}