// $Id: Sender.java,v 1.5.2.4 2003/09/23 22:39:55 idgay Exp $

/*									tab:4
 * "Copyright (c) 2000-2003 The Regents of the University  of California.  
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice, the following
 * two paragraphs and the author appear in all copies of this software.
 * 
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
 * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
 *
 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
 *
 * This file is distributed under the terms in the attached INTEL-LICENSE     
 * file. If you do not find these files, copies can be found by writing to
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300, Berkeley, CA, 
 * 94704.  Attention:  Intel License Inquiry.
 */
/* Authors:  David Gay  <dgay@intel-research.net>
 *           Intel Research Berkeley Lab
 *
 */

/**
 * @author David Gay <dgay@intel-research.net>
 * @author Intel Research Berkeley Lab
 */

package net.tinyos.message;

import net.tinyos.util.*;
import net.tinyos.packet.*;
import java.io.*;

/**
 * Sender class (send tinyos messages).<p>
 *
 * A sender class provides a simple interface built on Message for
 * sending tinyos messages to a SerialForwarder
 *
 * @version	2, 24 Jul 2003
 * @author	David Gay
 */
public class Sender {
    // If true, dump packet contents that are sent
    private static final boolean VERBOSE = false;

    byte groupId;
    PhoenixSource sender;

    private void init(int gid) {
        if (gid < MoteIF.ANY_GROUP_ID || gid > 0xff) {
	  throw new IllegalArgumentException("Cannot send messages to invalid group ID: " + gid);
	}
	// Use "default" group id when none specified (a few people will be
	// temporarily less confused)
	if (gid == MoteIF.ANY_GROUP_ID)
	    groupId = 0x7d;
	else
	    groupId = (byte)gid;
    }

    /**
     * Create a sender for group id gid talking to PhoenixSource forwarder
     * @param forwarder PhoenixSource with which we wish to send packets
     * @param gid group id to be placed in sent packets
     */
    public Sender(PhoenixSource forwarder, int gid) {
	sender = forwarder;
	packetSize = -1;
	init(gid);
    }

    /**
     * Create a sender talking to PhoenixSource forwarder. The group id of
     * sent packets will be arbitrary (for use with new TinyosBase)
     * @param forwarder PhoenixSource with which we wish to send packets
     */
    public Sender(PhoenixSource forwarder) {
	sender = forwarder;
	packetSize = -1;
	init(MoteIF.ANY_GROUP_ID);
    }

    /**
     * Send m to moteId via this Sender's SerialForwarder
     * @param moteId message destination
     * @param m message
     * @exception IOException thrown if message could not be sent
     */
    synchronized public void send(int moteId, Message m) throws IOException {
	int amType = m.amType();
	byte[] data = m.dataGet();

	if (amType < 0) {
	    throw new IOException("unknown AM type for message " +
				  m.getClass().getName());
	}

	TOSMsg packet;
	if (packetSize == -1) {
	    // normal case, a PhoenixSource
	    // XXX: hack: we don't leave any space for the crc, so 
	    // numElements_data() will be wrong. But we access the
	    // data area via dataSet/dataGet, so we're ok.
	    packet = new TOSMsg(TOSMsg.offset_data(0) + data.length);
	}
	else {
	    // legacy support
	    packet = new TOSMsg(packetSize);
	    // Set CRC to 1 in case we're going directly to a UART
	    packet.set_crc(1);
	}

	//  message header: destination, group id, and message type
	packet.set_addr(moteId);
	packet.set_group(groupId);
	packet.set_type((short)amType);
	packet.set_length((short)data.length);
	if (data.length >= (1L << TOSMsg.sizeBits_length()) &&
	    (packetSize != -1 &&
	     data.length > packet.numElements_data())) // only possible in legacy case...
	    throw new IOException("message too big (" + data.length + " bytes)");
	packet.dataSet(data, 0, packet.offset_data(0), data.length);

	byte[] packetData = packet.dataGet();
	if (sender != null) {
	    sender.writePacket(packetData);
	}
	else {
	    sfw.Write(packetData);
	}
	if (VERBOSE) Dump.dump("sent", packetData);
    }

    ////////////////  DEPRECATED ROUTINES /////////////////

    SerialStub sfw;
    int packetSize;

    /**
     * Create a sender for group id gid talking to SerialForwarder forwarder
     * @param forwarder SerialForwarder with which we wish to send packets
     * @param gid group id to be placed in sent packets
     * @deprecated Use the version which takes a PhoenixSource instead
     */
    public Sender(SerialStub forwarder, int gid) {
	this(forwarder, gid, SerialForwarderStub.PACKET_SIZE); 
    }

    /**
     * Create a sender for group id gid talking to SerialForwarder forwarder
     * @param forwarder SerialForwarder with which we wish to send packets
     * @param gid group id to be placed in sent packets
     * @param packet_size size of packets to send
     * @deprecated Use the version which takes a PhoenixSource instead
     */
    public Sender(SerialStub stub, int gid, int packet_size) {
	init(gid);
	sfw = stub;
	packetSize = packet_size;
    }
}