/*-*-c++-*-
 * $Id$
 *
 * This file is part of plptools.
 *
 *  Copyright (C) 1999  Philip Proudman <philip.proudman@btinternet.com>
 *  Copyright (C) 1999-2001 Fritz Elfert <felfert@to.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stream.h>
#include <stdlib.h>
#include <stdio.h>

#include "link.h"
#include "packet.h"
#include "bufferstore.h"
#include "bufferarray.h"

link::link(const char *fname, int baud, IOWatch & iow, unsigned short _verbose)
{
    p = new packet(fname, baud, iow);
    verbose = _verbose;
    idSent = 0;
    idLastGot = -1;
    newLink = true;
    somethingToSend = false;
    timesSent = 0;
    failed = false;
    for (int i; i < 256; i++)
	xoff[i] = false;
}

link::~link()
{
    flush();
    delete p;
}

void link::
reset() {
    idSent = 0;
    idLastGot = -1;
    newLink = true;
    somethingToSend = false;
    timesSent = 0;
    failed = false;
    for (int i; i < 256; i++)
	xoff[i] = false;
}

short int link::
getVerbose()
{
    return verbose;
}

void link::
setVerbose(short int _verbose)
{
    verbose = _verbose;
}

short int link::
getPktVerbose()
{
    return p->getVerbose();
}

void link::
setPktVerbose(short int _verbose)
{
    p->setVerbose(_verbose);
}

void link::
send(const bufferStore & buff)
{
    if (buff.getLen() > 300)
	failed = true;
    else
	sendQueue += buff;
}

void link::
purgeQueue(int channel)
{
    bufferArray hsendQueue;
    bufferStore b;

    while (!sendQueue.empty()) {
	b = sendQueue.pop();
	if (b.getByte(0) != channel)
	    hsendQueue += b;
    }
    sendQueue = hsendQueue;
}

bufferArray link::
poll()
{
    bufferArray ret;
    bufferStore buff;
    unsigned char type;

    // RX loop
    while (p->get(type, buff)) {
	int seq = type & 0x0f;
	bufferStore blank;
	type &= 0xf0;

	// Support for incoming extended sequence numbers
	if (seq & 0x08) {
	    int tseq = buff.getByte(0);
	    buff.discardFirstBytes(1);
	    seq = (tseq << 3) | (seq & 0x07);
	}

	switch (type) {
	    case 0x30:
		// Normal data
		if (verbose & LNK_DEBUG_LOG) {
		    cout << "link: << dat seq=" << seq ;
		    if (verbose & LNK_DEBUG_DUMP)
			cout << " " << buff << endl;
		    else
			cout << " len=" << buff.getLen() << endl;
		}
		// Send ack
		if (idLastGot != seq) {
		    idLastGot = seq;
		    // Must check for XOFF/XON ncp frames HERE!
		    if ((buff.getLen() == 3) && (buff.getByte(0) == 0)) {
			switch (buff.getByte(2)) {
			    case 1:
				// XOFF
				xoff[buff.getByte(1)] = true;
				if (verbose & LNK_DEBUG_LOG)
				    cout << "link: got XOFF for channel " << buff.getByte(1) << endl;
				break;
			    case 2:
				// XON
				xoff[buff.getByte(1)] = false;
				if (verbose & LNK_DEBUG_LOG)
				    cout << "link: got XON for channel " << buff.getByte(1) << endl;
				break;
			    default:
				ret += buff;
			}
		    } else
			ret += buff;
		} else {
		    if (verbose & LNK_DEBUG_LOG)
			cout << "link: DUP\n";
		}
		if (verbose & LNK_DEBUG_LOG)
		    cout << "link: >> ack seq=" << seq << endl;
		blank.init();

		// Support for incoming extended sequence numbers
		if (seq > 7) {
		    blank.addByte(seq >> 3);
		    seq &= 0x07;
		    seq |= 0x08;
		}

		p->send(seq, blank);
		break;

	    case 0x00:
		// Incoming ack
		if (seq == idSent) {
		    if (verbose & LNK_DEBUG_LOG) {
			cout << "link: << ack seq=" << seq ;
			if (verbose & LNK_DEBUG_DUMP)
			    cout << " " << buff;
			cout << endl;
		    }
		    somethingToSend = false;
		    timesSent = 0;
		}
		break;

	    case 0x20:
		// New link
		if (verbose & LNK_DEBUG_LOG) {
		    cout << "link: << lrq seq=" << seq;
		    if (verbose & LNK_DEBUG_DUMP)
			cout << " " << buff;
		    cout << endl;
		}
		idLastGot = 0;
		if (verbose & LNK_DEBUG_LOG)
		    cout << "link: >> lack seq=" << seq << endl;
		somethingToSend = false;
		blank.init();
		p->send(idLastGot, blank);
		break;

	    case 0x10:
		// Disconnect
		if (verbose & LNK_DEBUG_LOG)
		    cout << "link: << DISC" << endl;
		failed = true;
		return ret;
	}
    }

    if (p->linkFailed()) {
	failed = true;
	return ret;
    }

    if (!somethingToSend) {
	countToResend = 0;
	if (newLink) {
	    somethingToSend = true;
	    toSend.init();
	    newLink = false;
	    idSent = 0;
	} else {
	    bufferArray hsendQueue;

	    while (!sendQueue.empty()) {
		toSend = sendQueue.pop();
		int remoteChan = toSend.getByte(0);
		if (xoff[remoteChan])
		    hsendQueue += toSend;
		else {
		    somethingToSend = true;
		    idSent++;
		    if (idSent > 7)
			idSent = 0;
		    break;
		}
	    }
	    sendQueue = hsendQueue + sendQueue;
	}
    }

    if (somethingToSend) {
	if (countToResend == 0) {
	    timesSent++;
	    if (timesSent == 5) {
		failed = true;
	    } else {
		if (toSend.empty()) {
		    // Request for new link
		    if (verbose & LNK_DEBUG_LOG)
			cout << "link: >> lrq seq=" << idSent << endl;
		    p->send(0x20 + idSent, toSend);
		} else {
		    if (verbose & LNK_DEBUG_LOG) {
			cout << "link: >> data seq=" << idSent;
			if (verbose & LNK_DEBUG_DUMP)
			    cout << " " << toSend;
			cout << endl;
		    }
		    p->send(0x30 + idSent, toSend);
		}
		countToResend = 5;
	    }
	} else
	    countToResend--;
    }

    return ret;
}

void link::
flush() {
    while ((!failed) && stuffToSend())
	poll();
}

bool link::
stuffToSend()
{
    return (!failed && (somethingToSend || !sendQueue.empty()));
}

bool link::
hasFailed()
{
    return failed;
}

/*
 * Local variables:
 * c-basic-offset: 4
 * End:
 */