/*
 *  mur.sat
 *
 *  Somewhen in the year 20xx, mur.at will have a nano satellite launched
 *  into a low earth orbit (310 km above the surface of our planet). The
 *  satellite itself is a TubeSat personal satellite kit, developed and
 *  launched by interorbital systems. mur.sat is a joint venture of mur.at,
 *  ESC im Labor and realraum.
 *
 *  Please visit the project hompage at sat.mur.at for further information.
 * 
 *
 *  Copyright (C) 2011 Christian Pointner <equinox@mur.at>
 *                         
 *  This file is part of mur.sat.
 *
 *  mur.sat 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 3 of the License, or
 *  any later version.
 *
 *  mur.sat 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 mur.sat. If not, see <http://www.gnu.org/licenses/>.
 */

#include <unistd.h>
#include <stdio.h>
#include <termios.h>
#include <ctype.h>

char sign2bin(c)
{
  switch(c) {
  case 'D': return 0;
  case '1': return 1;
  case '2': return 2;
  case '3': return 3;
  case '4': return 4;
  case '5': return 5;
  case '6': return 6;
  case '7': return 7;
  case '8': return 8;
  case '9': return 9;
  case '0': return 10;
  case '*': return 11;
  case '#': return 12;
  case 'A': return 13;
  case 'B': return 14;
  case 'C': return 15;
  }
  return 0;
}

char bin2sign(c)
{
  switch(c) {
  case 0: return 'D';
  case 1: return '1';
  case 2: return '2';
  case 3: return '3';
  case 4: return '4';
  case 5: return '5';
  case 6: return '6';
  case 7: return '7';
  case 8: return '8';
  case 9: return '9';
  case 10: return '0';
  case 11: return '*';
  case 12: return '#';
  case 13: return 'A';
  case 14: return 'B';
  case 15: return 'C';
  }
  return 0;
}

void send_crx_string(c)
{
  c = toupper(c);
  if(c == '#' || c == '*' ||
     (c >= '0' && c <= '9') ||
     (c >= 'A' && c <= 'D') ) {
    char cs = bin2sign(0x0A ^ sign2bin(c));
    int ret = write(1, &"#42", 3);
    ret = write(1, &c, 1);
    ret = write(1, &cs, 1);
    ret = write(1, &" ", 1);
  }
}

int main (int argc, char *argv[])
{
  struct termios T;
  tcgetattr(0, &T);
  T.c_lflag &= ~ECHO;
  T.c_lflag &= ~ICANON;
  tcsetattr(0, TCSANOW, &T);

  char c;
  for(;;) {
    int ret = read(0, &c, 1);
    if(!ret) break;
    if(ret == 1) send_crx_string(c);
    else {
      perror("read error: ");
      return 1;
    }
  }

  return 0;
}