/*****************************************************************************/

/*
 *      rtty.c  --  RTTY "uart" implementation.
 *
 *      Copyright (C) 1996  Thomas Sailer (sailer@ife.ee.ethz.ch)
 *        Swiss Federal Institute of Technology (ETH), Electronics Lab
 *
 *      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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*****************************************************************************/
      
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h> 
#include <assert.h>
#include <syslog.h>
#include <string.h>
#include <stdio.h>

#include "fskl1.h"
#include "fskutil.h"
#include "msg.h"
#include "main.h"
#include "rtty.h"


/* --------------------------------------------------------------------- */

#define SHIFT_NUMBER   27
#define SHIFT_LETTER   31

#define IDLE_SHIFT_FREQ 10

/* --------------------------------------------------------------------- */

#define INVAL "\001"
#define BELL  "\007" 
#define WRU   "$"

#define LETTERS INVAL     "E\nA SIU\rDRJNFCKTZLWHYPQOBG" INVAL "MXV" INVAL
#define NUMBERS_DL INVAL  "3\n- '87\r" WRU "4,:(5+)26019?" INVAL "./=" INVAL
#define NUMBERS_GB INVAL  "3\n- '87\r" WRU "4" BELL ",%:(5+)2#6019?@" INVAL "./=" INVAL
#define NUMBERS_USA INVAL "3\n- " BELL "87\r" WRU "4',!:(5\")2*6019?&" INVAL "./;" INVAL

static const char rtty_chars[65] = LETTERS NUMBERS_DL;

/* --------------------------------------------------------------------- */

static struct {
	unsigned int baud;
	int rxinvert, txinvert;
} rp = { 45, 0, 0 };

static struct {
	unsigned int figmode;
	int idle_cnt;
} rs;

/* --------------------------------------------------------------------- */

#define NUMBUF            4
#define BUFLEN          128
#define RXOVERSAMPLING    5

static l1_time_t buftimes[NUMBUF];
static l1_soft_t buf[2*NUMBUF][BUFLEN];

#define NUMTXCHARS 4

static l1_time_t txtimes[NUMTXCHARS];
static unsigned char txchars[NUMTXCHARS];

/* --------------------------------------------------------------------- */

void rtty_set_params(unsigned int baud, int rxinvert, int txinvert)
{
	errprintf(SEV_INFO, "rtty params: baud %u invert%s%s\n",
		  baud, rxinvert ? " RX" : "", txinvert ? " TX" : "");
	if (baud >= 10 && baud <= 1000)
		rp.baud = baud;
	rp.rxinvert = !!rxinvert;
	rp.txinvert = !!txinvert;
}

/* --------------------------------------------------------------------- */

void rtty_reset_uppercase(void)
{
	rs.figmode = 0;
}

void rtty_reset_figurecase(void)
{
	rs.figmode = 0x20;
}

/* --------------------------------------------------------------------- */

void *mode_rtty_rx(void *dummy)
{
	int i, j;
	l1_soft_t *s;
	l1_time_t tm_inc = 1000000/rp.baud/RXOVERSAMPLING;
	int deaf = 0;
	unsigned char rxchar;

	modefamily = FSK;
       	l1_fsk_clear_requests();
	errprintf(SEV_INFO, "mode: rtty rx\n");
//	bufprintf(HFAPP_MSG_DATA_STATUS, "RTTY RX %u BAUD LETTERS", rp.baud);
	rs.figmode = 0;
	memset(buf, 0, sizeof(buf));
	buftimes[0] = l1_get_current_time() + 100000;
	for (i = 1; i < NUMBUF; i++)
		buftimes[i] = buftimes[i-1] + BUFLEN * tm_inc;
	for (i = 0; i < NUMBUF; i++)
		l1_fsk_rx_request(buftimes[i], 
		    tm_inc, 0, rp.baud, i, BUFLEN, buf[i]);
	send_short_msg(HFAPP_MSG_STATE_RTTY_RX, ERR_NOERR);
	for (;;) {
	    i = l1_fsk_wait_request();
	    //errprintf(SEV_INFO, "rttyrx: req %d ready\n", i);
	    assert(i >= 0);
	    assert(i < NUMBUF);
	    memcpy(s = buf[i+NUMBUF], buf[i], sizeof(buf[i]));
	    for (j = 0; j < BUFLEN; j++, s++) {
        	//printf("%c", '0' + (*s >= 0));
		if (deaf > 0) {
		    deaf--;
		    continue;
		}
		if ((!rp.rxinvert && s[-RXOVERSAMPLING*6-1-RXOVERSAMPLING/2] 
			>= 0 && 
		    s[-RXOVERSAMPLING*6-RXOVERSAMPLING/2] < 0) || 
		    (rp.rxinvert && s[-RXOVERSAMPLING*6-1-RXOVERSAMPLING/2] 
			< 0 && 
		    s[-RXOVERSAMPLING*6-RXOVERSAMPLING/2] >= 0)) 
		    {
			soft_to_hard(s-RXOVERSAMPLING*5, &rxchar, 6, 
			    RXOVERSAMPLING, rp.rxinvert);
			if (!(rxchar & 0x20))
			    continue;
			deaf = 6*RXOVERSAMPLING;
			rxchar &= 0x1f;
			bufprintf(HFAPP_MSG_DATA_MONITOR, "%02x ", (int)rxchar);
			if (rxchar == SHIFT_NUMBER)
			    rs.figmode = 0x20;
			else if (rxchar == SHIFT_LETTER)
			    rs.figmode = 0;
			else
			    bufprintf(HFAPP_MSG_DATA_RECEIVE, "%c", 
				rtty_chars[rxchar + rs.figmode]);
//			bufprintf(HFAPP_MSG_DATA_STATUS, 
//			    "RTTY RX %u BAUD %s", rp.baud, rs.figmode ? 
//			    "FIGURES" : "LETTERS");
			}
		}
	printf("\n");
        fflush(stdout);
	buftimes[i] += NUMBUF * BUFLEN * tm_inc;
	l1_fsk_rx_request(buftimes[i], tm_inc, 0, rp.baud, i, BUFLEN, buf[i]);
	}
}

/* --------------------------------------------------------------------- */

static unsigned char rtty_getcharbits(void)
{
	unsigned char *bp;
	unsigned short ch;
	char *diddle = "LTRS "; 
	int i, diddle_start = 35, eof_ack_start = 5; 
	/*  We wait for the first kbd_ack() for eof_ack_start times `KBD_EOF` 
	    to prevent a race condition between the autorx() function of hfterm 
	    (in rxtx.c) and the real transmit here which lasts some time.
	   
	    The diddle_start count should be bigger than eof_ack_start because
	    the diddle might be confusing if it comes too early.
	*/
	static int idlecount = 0;

	for (;;) {
	    kbd_negack();
	    if ((ch = kbd_get()) == KBD_EOF) {
		idlecount++;
		//bufprintf(HFAPP_MSG_DATA_STATUS, "KBD_EOF %d", idlecount);
/* // orig by Tom
		if ((--rs.idle_cnt) <= 0) {
		    rs.idle_cnt = IDLE_SHIFT_FREQ;
		    return(rs.figmode ? SHIFT_NUMBER << 1 : SHIFT_LETTER << 1) | 0xc0;
		}
*/
// new by Gnther, tnx for suggestion by Martin Ewing, ewing@alum.mit.edu
		if (idlecount >= eof_ack_start) {
		    //bufprintf(HFAPP_MSG_DATA_STATUS, 
		    //"I kbd_ack() the EOF at %d", idlecount);
		    kbd_ack();
		}
		if (idlecount >= diddle_start) {
		    /*bufprintf(HFAPP_MSG_DATA_STATUS, 
			"I start the diddle at %d", idlecount);
		    bufprintf(HFAPP_MSG_DATA_STATUS, 
		    	"diddle letter %d", idlecount % strlen(diddle)); */
		    ch = diddle[idlecount % strlen(diddle)];
		} else 
		return 0xff;
	    } else {
		idlecount = 0; 
		//something to transmit: -> reset of idlecount
	    }
	    //bufprintf(HFAPP_MSG_DATA_STATUS, "idlecount: %d", idlecount);
	    ch &= KBD_CHAR;
	    if (ch >= 'a' && ch <= 'z')
		ch -= 'a'-'A';
	    else if (ch == (((unsigned)'') & 0xff))
		ch = '';
	    else if (ch == (((unsigned)'') & 0xff))
		ch = '';
	    else if (ch == (((unsigned)'') & 0xff))
		ch = '';
	    if (!(bp = memchr(rtty_chars, ch, 64))) {
	 	kbd_ack();
		continue;
	    }
	    i = bp - (unsigned char *)rtty_chars;
	    if ((i & 0x20) != rs.figmode) {
		rs.figmode = (i & 0x20);
	    return 
		(rs.figmode ? SHIFT_NUMBER << 1 : SHIFT_LETTER << 1) | 0xc0;
	}
	kbd_ack();
/*  i tried to move kbd_ack() to after the real tx 
    so that autorx() can work correctly
    but: all letters are sent 3-4 times then ... ;-(
*/
	return (i << 1) | 0xc0;
	}
}

/* --------------------------------------------------------------------- */

void *mode_rtty_tx(void *dummy)
{
	l1_time_t tm_inc = 1000000/rp.baud;
	l1_time_t tm_chinc = 7500000/rp.baud;
	int i;

      	modefamily = FSK;
       	l1_fsk_clear_requests();
	errprintf(SEV_INFO, "mode: rtty tx\n");
	bufprintf(HFAPP_MSG_DATA_STATUS, "RTTY TX %u BAUD LETTERS", rp.baud);
	rs.idle_cnt = IDLE_SHIFT_FREQ;
	rs.figmode = 0;
	memset(txchars, 0xff, sizeof(txchars));
	txtimes[0] = l1_get_current_time() + 100000;
	for (i = 1; i < NUMTXCHARS; i++)
		txtimes[i] = txtimes[i-1] + tm_chinc;
	for (i = 0; i < NUMTXCHARS; i++)
		l1_fsk_tx_request
		    (txtimes[i], tm_inc, 0, rp.txinvert, i, 8, txchars+i);
	send_short_msg(HFAPP_MSG_STATE_RTTY_TX, ERR_NOERR);
	for (;;) {
		i = l1_fsk_wait_request();
		errprintf(SEV_INFO, "rttytx: req %d ready\n", i);
		assert(i >= 0);
		assert(i < NUMTXCHARS);
		txchars[i] = rtty_getcharbits();
		if (txchars[i] != 0xff)
		    bufprintf(HFAPP_MSG_DATA_MONITOR, 
//			"%02x\n", (txchars[i] >> 1) & 0x1f);
			"%02d ", (int)((txchars[i] >> 1) & 0x1f));
		txtimes[i] += NUMTXCHARS*tm_chinc;
		l1_fsk_tx_request
		    (txtimes[i], tm_inc, 0, rp.txinvert, i, 8, txchars+i);
//		if (i == 0)
// 			bufprintf(HFAPP_MSG_DATA_STATUS, 
//			"RTTY TX %u BAUD %s", rp.baud, rs.figmode ? "FIGURES" : "LETTERS");
// i tried to put it here for autorx to work but... see above
//		kbd_ack();
	}
}

/* --------------------------------------------------------------------- */