/*
 * $Id$
 *
 * Copyright (C) 2003-2015 JNode.org
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; If not, write to the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
package java.nio.channels;

import java.io.InputStream;
import java.io.FileInputStream;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import gnu.java.nio.channels.FileChannelImpl;
import gnu.java.nio.ChannelInputStream;
import gnu.java.nio.ChannelOutputStream;

/**
 *
 */
public class NativeVMChannels {
    /**
     * Constructs a stream that reads bytes from the given channel.
     */
    static InputStream newInputStream(ReadableByteChannel ch) {
        if (ch instanceof FileChannelImpl)
            return (FileInputStream) createStream(FileInputStream.class, ch);

        return new ChannelInputStream(ch);
    }

    /**
     * Constructs a stream that writes bytes to the given channel.
     */
    static OutputStream newOutputStream(WritableByteChannel ch) {
        if (ch instanceof FileChannelImpl)
            return (FileOutputStream) createStream(FileOutputStream.class, ch);

        return new ChannelOutputStream(ch);
    }

    private static Object createStream(Class streamClass, Channel ch) {
        try {
            Class[] argTypes = new Class[1];
            argTypes[0] = FileChannelImpl.class;
            Constructor constructor = streamClass.getDeclaredConstructor(argTypes);
            constructor.setAccessible(true);
            Object[] args = new Object[1];
            args[0] = ch;
            return constructor.newInstance(args);
        } catch (IllegalAccessException e) {
            // Ignored.
        } catch (InstantiationException e) {
            // Ignored.
        } catch (InvocationTargetException e) {
            // Ignored.
        } catch (NoSuchMethodException e) {
            // Ignored.
        }

        return null;
    }
}