/* r8.c - Connect stdin and stdout to R8's serial port */

/*
 *  Copyright (C) 1995 Jeffrey Chilton
 *
 *  Permission is granted to anyone to make or distribute copies of
 *  this program, in any medium, provided that the copyright notice
 *  and permission notice are preserved, and that the distributor
 *  grants the recipient permission for further redistribution as
 *  permitted by this notice.
 *  
 *  Author's E-mail address:  jwc@chilton.com
 *  
 */

#include <sys/errno.h>
#include <sys/types.h>

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

#define RADIO "/dev/tty00"
#define LOCKFILE "/tmp/radio.lock"
#define OPTIONS "fre:"

extern char *optarg;

main(argc, argv)
int argc;
char *argv[];
{
    register int i, j;
    int force;
    int ignore;
    int duration;
    int lfd, rfd;
    char rec[256];
    time_t embargo;
    time_t current_time;
    struct termios rti;
    char buffer[80];
    char c;
    int rc;

    /* 
     *  Get options:  
     *
     *    -r, ignore embargo (only going to read radio) 
     *    -f, ignore lock and embargo (manual operation)
     *    -e <n>, embargo for n seconds (for recording)
     */

    force = 0;
    ignore = 0;
    duration = 0;

    rc = getopt(argc, argv, OPTIONS);
    while (rc != -1)
    {
	switch (rc)
	{
	    case 'e':
		duration = atoi(optarg);
		break;
	    case 'f':
		force = 1;
		break;
	    case 'r':
		ignore = 1;
		break;
	}
	rc = getopt(argc, argv, OPTIONS);
    }

    /* Locking this file gives us exclusive use of the serial port */

    if (!force)
    {
	lfd = open(LOCKFILE, O_RDWR | O_CREAT, (mode_t )0x1a0);
	if (lfd < 0)
	{
	    perror("lockfile open fails");
	    printf("ERROR\n");
	    goto out;
	}

	rc = flock(lfd, LOCK_EX | LOCK_NB);
	if (rc < 0)
	{
	    printf("LOCKED\n");
	    goto out;
	}

	/* The file contains the embargo-until time */

	rc = read(lfd, rec, 256);
	if (rc < 0)
	{
	    perror("lockfile read fails");
	    printf("ERROR\n");
	    goto out;
	}

	embargo = atol(rec);

	/* If under embargo, and not ignoring, print seconds to go */

	if (!ignore)
	{
	    time(&current_time);
	    if (embargo > current_time)
	    {
		printf("%d\n", embargo - current_time);
		goto out;
	    }
	}

	/* If placing embargo write lift time to file */

	if (duration > 0)
	{
	    sprintf(rec, "%d\n", current_time + duration);
	    lseek(lfd, 0, SEEK_SET);
	    rc = write(lfd, rec, strlen(rec));
	    if (rc < 0)
	    {
		perror("lockfile write fails");
		printf("ERROR\n");
		goto out;
	    }
	}
    }

    /* Ok to open and condition the serial port now */

    rfd = open(RADIO, O_RDWR);
    if (rfd < 0)
    {
	perror("device open fails");
	printf("ERROR\n");
	goto out;
    }

    rti.c_iflag = IGNBRK;
    rti.c_oflag = 0;
    rti.c_cflag = CREAD | CS7 | PARENB | CRTSCTS;
    rti.c_lflag = 0;
    rti.c_cc[VMIN] = 0;
    rti.c_cc[VTIME] = 1;
    rti.c_ispeed = B9600;
    rti.c_ospeed = B9600;

    rc = tcsetattr(rfd, TCSAFLUSH, &rti);
    if (rc < 0)
    {
	perror("tcsetattr fails");
	printf("ERROR\n");
	goto out;
    }

    /* Send commands and collect responses */

    fgets(buffer, 80, stdin);
    while (!feof(stdin))
    {
	buffer[strlen(buffer) - 1] = '\r';

	/* Make sure radio is quiet */

	rc = read(rfd, &c, 1);
	while (rc > 0)
	{
	    rc = read(rfd, &c, 1);
	}

	/* Send command */

	i = 0;
	while (buffer[i])
	{
	    rc = ioctl(rfd, TIOCDRAIN, 0);
	    if (rc == -1)
	    {
		perror("TIOCDRAIN ioctl fails");
		printf("ERROR\n");
		goto out;
	    }
	    rc = write(rfd, &buffer[i], 1);
	    if (rc < 0)
	    {
		perror("device write fails");
		printf("ERROR\n");
		goto out;
	    }
	    i++;
	}

	/* Collect response */

	strcpy(buffer, "<ERR>");

	j = 0;
	for (i = 0; i < 25; i++)
	{
	    rc = read(rfd, &c, 1);
	    if (rc == 1)
	    {
		if (c == '\n' || c == '\r')
		{
		    buffer[j] = '\0';
		    break;
		}
		buffer[j] = c;
		j++;
	    }
	}

	printf("%s\n", buffer);

	fgets(buffer, 80, stdin);

    }

    /* Re-enables the knobs and buttons */

    close(rfd);
    open(RADIO, O_RDWR);

out:

    exit(0);

}