// SPDX-License-Identifier: WTFPL

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

static int fd = -1;

int serprintf(char *fmt, ...)
{
	va_list ap;
	int len;
	char buf[4096];

	va_start(ap, fmt);
	len = vsnprintf(buf, sizeof(buf), fmt, ap);
	va_end(ap);

	if (fd >= 0)
		write(fd, buf, len);

	return len;
}

void serprintf_init(char *dev, int speed)
{
	struct termios	t;

	if ((fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY)) < 0)
		return;

	memset(&t, 0, sizeof(t));

	cfsetospeed(&t, speed);
	cfsetispeed(&t, speed);

	t.c_cflag = CREAD | CLOCAL | CS8;

	t.c_iflag = INPCK;
	t.c_oflag = 0;
	t.c_lflag = 0;

	t.c_cc[VTIME] = 0;
	t.c_cc[VMIN] = 1;

	tcflush(fd, TCIFLUSH);
	tcsetattr(fd, TCSANOW, &t);
}