#include "pwf.h"
#include <pthread.h>

static unsigned atou(char** s) {
  unsigned x;
  for (x = 0; **s - '0' < 10U; ++*s)
    x = 10 * x + (**s - '0');
  return x;
}

int __getgrent_a(FILE* f,
                 struct group* gr,
                 char** line,
                 size_t* size,
                 char*** mem,
                 size_t* nmem,
                 struct group** res) {
  ssize_t l;
  char *s, *mems;
  size_t i;
  int rv = 0;
  int cs;
  pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
  for (;;) {
    if ((l = getline(line, size, f)) < 0) {
      rv = ferror(f) ? errno : 0;
      free(*line);
      *line = 0;
      gr = 0;
      goto end;
    }
    line[0][l - 1] = 0;

    s = line[0];
    gr->gr_name = s++;
    if (!(s = strchr(s, ':')))
      continue;

    *s++ = 0;
    gr->gr_passwd = s;
    if (!(s = strchr(s, ':')))
      continue;

    *s++ = 0;
    gr->gr_gid = atou(&s);
    if (*s != ':')
      continue;

    *s++ = 0;
    mems = s;
    break;
  }

  for (*nmem = !!*s; *s; s++)
    if (*s == ',')
      ++*nmem;
  free(*mem);
  *mem = calloc(sizeof(char*), *nmem + 1);
  if (!*mem) {
    rv = errno;
    free(*line);
    *line = 0;
    gr = 0;
    goto end;
  }
  if (*mems) {
    mem[0][0] = mems;
    for (s = mems, i = 0; *s; s++)
      if (*s == ',')
        *s++ = 0, mem[0][++i] = s;
    mem[0][++i] = 0;
  } else {
    mem[0][0] = 0;
  }
  gr->gr_mem = *mem;
end:
  pthread_setcancelstate(cs, 0);
  *res = gr;
  if (rv)
    errno = rv;
  return rv;
}