#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <memory.h>
#include <malloc.h>
#include <termios.h>
#include <fcntl.h>
#include <unistd.h>

#include "iqbasic.h"

#define DIE(...) error_at_line(1, errno, __FILE__, __LINE__, __VA_ARGS__)

void vario_send(int fd, const char *line)
{
  int len = strlen(line);
  char *buf = (char*)malloc(sizeof(char)*len+3);
  int rc;
  sprintf(buf, "%s\r\n", line);
  do {
    rc = write(fd, buf, len+2);
  } while (rc == -1 && errno == EINTR);
  if (rc == -1)
    DIE("write");
}

int vario_recv(int fd, char *buf, int maxlen)
{
  int pos = 0;
  int n;
  char c;

  do {
    do {
      n = read(fd, &c, 1);
    } while(n == -1 && errno == EINTR);

    if(n == -1)
      DIE("read");
    if(n == 1)
      buf[pos++] = c;

  } while(c != '\n' && pos < maxlen);

  if(pos >= maxlen)
    DIE("buffer too small");

  return pos;
}

int vario_open(char *device)
{
  int fd = open(device, O_NOCTTY | O_NONBLOCK | O_RDWR);
  if (fd == -1)
    DIE("%s", device);
  if (tcflush(fd, TCIOFLUSH) == -1)
    error(1, errno, "tcflush %s", device, strerror(errno));

  struct termios termios;
  memset(&termios, 0, sizeof termios);
  termios.c_iflag = IGNPAR;
  termios.c_cflag = CLOCAL | CREAD | CS8;
  cfsetispeed(&termios, B57600);
  cfsetospeed(&termios, B57600);
  if (tcsetattr(fd, TCSANOW, &termios) == -1)
    DIE("tcsetattr: %s: %s", device, strerror(errno));

  return fd;
}

void vario_close(int fd)
{
  if (close(fd) == -1)
    DIE("close: %s", strerror(errno));
}