/* "Copyleft" Chris Baird <cjb@brushtail.apana.org.au> */

#include <sys/types.h>		/* write(2) */
#include <sys/uio.h>		/* write(2) */
#include <stdio.h>
#include <fcntl.h>		/* open(2) */
#include <stdlib.h>		/* atof(3) */
#include <unistd.h>		/* usleep(3), getopt(3), write(2) */
#include <err.h>		/* err(3) */
#include <string.h>		/* strncpy(3) */
#include <termios.h>		/* line speed setting */

extern char *optarg;
extern int optind;

/* default line speed */
int output_baud = 300;

/* default device to use */
#define DEFAULT_LINE "/dev/tty00"

/* the delay after a newline (in seconds); slow software will need more time */
float newline_delay = 0.75;

/* the delay for each character, relative to line speed; if talking to a BASIC
 * program that reads characters individually make it at least 2 (at 300 bps)
 */
float character_fudge = 2.0;

int character_echo = 1;

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

char output_device[32];

int usage (void)
{
  fprintf (stderr,
	   "Usage: u2a\n\t[-l output device (%s)]\n"
	   "\t[-e disable character echo\n"
	   "\t[-b line speed (%d)]\n"
	   "\t[-n newline delay in seconds (%.2f)]\n"
	   "\t[-c relative per character delay (%.2f)]\n",
	   output_device, output_baud,
	   newline_delay, character_fudge);
  exit (1);
}

int main(int argc, char *argv[])
{
  FILE *fp;
  struct termios origterm;
  int output_fd, c;
  strncpy (output_device, DEFAULT_LINE, 11);

  while ((c = getopt(argc, argv, "hl:b:n:c:e")) != -1)
    switch(c)
      {
      case 'e':
	character_echo = 0;
	break;
      case 'h':
	usage ();
	break;
      case 'l':
	strncpy (output_device, optarg, 31);
	/* sanity check for existing device/file later */
	break;
      case 'b':
	output_baud = atoi(optarg);
	if ((output_baud < 50) || (output_baud >500000))
	  err (1, "Unacceptable line speed \"%d\"\n", output_baud);
	break;
      case 'n':
	newline_delay = atof(optarg);
	if ((newline_delay < 0.0) || (newline_delay > 100.0))
	  err (1, "Unacceptable newline delay \"%.2f\"\n", newline_delay);
	break;
      case 'c':
	character_fudge = atof(optarg);
	if ((character_fudge < 1.0) || (character_fudge > 100.0))
	  err (1, "Unacceptable character delay \"%.2f\"\n", character_fudge);
	break;
      }
  argc -= optind;
  argv += optind;

  if (argv[0] == NULL)
    usage();
  fp = fopen (argv[0], "r");
  if (fp == NULL)
    err (1, "could not open \"%s\"\n", argv[argc]);

  /* open outputline */
  output_fd = open (output_device, O_WRONLY|O_EXLOCK, NULL);
  if (output_fd == -1)
    err (1, "Unable to open \"%s\"", output_device);

  if (tcgetattr (output_fd, &origterm) < 0)
    warn ("unable retrieve line settings");
  origterm.c_cflag &= ~(CSIZE|CRTSCTS|MDMBUF);
  origterm.c_cflag |= CS8|PARENB|PARODD|HUPCL|CLOCAL;
  cfsetospeed (&origterm, output_baud);
  if (tcsetattr (output_fd, TCSADRAIN, &origterm) < 0)
    warn ("unable to configure line settings");

  while ((c = fgetc(fp)) != EOF)
    {
      if (character_echo)
	write (2, &c, 1);
      if (c == 10)
	c = 13;
      write (output_fd, &c, 1);
      if (c == 13)
	{
	  sleep ((int)newline_delay);
	  usleep (1000000 * (float)(newline_delay - (int)newline_delay));
	}
      else
	usleep (((long)10000000 * (long)character_fudge) / (float)output_baud);
    }

  fclose (fp);
  close (output_fd);
  fprintf (stderr, "%c*** TRANSFER COMPLETE ***%c\n", 7, 7);
  return 0;
}