/*
 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
 * Please refer to the LICENSE.txt for licensing details.
 */
package ch.ethz.ssh2;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;

import ch.ethz.ssh2.channel.Channel;
import ch.ethz.ssh2.channel.ChannelManager;

/**
 * A <code>LocalStreamForwarder</code> forwards an Input- and Outputstream
 * pair via the secure tunnel to another host (which may or may not be identical
 * to the remote SSH-2 server).
 *
 * @author Christian Plattner
 * @version 2.50, 03/15/10
 */
public class LocalStreamForwarder {
    private ChannelManager cm;

    private Channel cn;

    LocalStreamForwarder(ChannelManager cm, String host_to_connect, int port_to_connect) throws IOException {
        this.cm = cm;
        cn = cm.openDirectTCPIPChannel(host_to_connect, port_to_connect,
                                       InetAddress.getLocalHost().getHostAddress(), 0);
    }

    /**
     * @return An <code>InputStream</code> object.
     * @throws IOException
     */
    public InputStream getInputStream() throws IOException {
        return cn.getStdoutStream();
    }

    /**
     * Get the OutputStream. Please be aware that the implementation MAY use an
     * internal buffer. To make sure that the buffered data is sent over the
     * tunnel, you have to call the <code>flush</code> method of the
     * <code>OutputStream</code>. To signal EOF, please use the
     * <code>close</code> method of the <code>OutputStream</code>.
     *
     * @return An <code>OutputStream</code> object.
     * @throws IOException
     */
    public OutputStream getOutputStream() throws IOException {
        return cn.getStdinStream();
    }

    /**
     * Close the underlying SSH forwarding channel and free up resources.
     * You can also use this method to force the shutdown of the underlying
     * forwarding channel. Pending output (OutputStream not flushed) will NOT
     * be sent. Pending input (InputStream) can still be read. If the shutdown
     * operation is already in progress (initiated from either side), then this
     * call is a no-op.
     *
     * @throws IOException
     */
    public void close() throws IOException {
        cm.closeChannel(cn, "Closed due to user request.", true);
    }
}