#include <caml/mlvalues.h>
#include <caml/alloc.h>
#include <caml/memory.h>
#include <caml/fail.h>
#include <caml/unixsupport.h>

#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/user.h>
#include <sys/sysctl.h>
#include <net/if.h>

#ifdef __FreeBSD__
#include <net/if_mib.h>
#endif

#define Val32 caml_copy_int32
#define Val64 caml_copy_int64

#ifdef __FreeBSD__
CAMLprim value vmmanage_sysctl_rusage (value pid_r) {
  CAMLparam1(pid_r);
  CAMLlocal3(res, utime, stime);
  int name[4];
  int error;
  size_t len;
  struct kinfo_proc p;
  struct rusage ru;

  len = sizeof(p);
  name[0] = CTL_KERN;
  name[1] = KERN_PROC;
  name[2] = KERN_PROC_PID;
  name[3] = Int_val(pid_r);

  error = sysctl(name, nitems(name), &p, &len, NULL, 0);
  if (error < 0)
    uerror("sysctl", Nothing);

  if (ru.ru_utime.tv_usec < 0 || ru.ru_utime.tv_usec > 999999999 ||
      ru.ru_stime.tv_usec < 0 || ru.ru_stime.tv_usec > 999999999)
    uerror("sysctl", Nothing);

  ru = p.ki_rusage;
  utime = caml_alloc(2, 0);
  Store_field (utime, 0, Val64(ru.ru_utime.tv_sec));
  Store_field (utime, 1, Val_int(ru.ru_utime.tv_usec));
  stime = caml_alloc(2, 0);
  Store_field (stime, 0, Val64(ru.ru_stime.tv_sec));
  Store_field (stime, 1, Val_int(ru.ru_stime.tv_usec));
  res = caml_alloc(16, 0);
  Store_field (res, 0, utime);
  Store_field (res, 1, stime);
  Store_field (res, 2, Val64(ru.ru_maxrss));
  Store_field (res, 3, Val64(ru.ru_ixrss));
  Store_field (res, 4, Val64(ru.ru_idrss));
  Store_field (res, 5, Val64(ru.ru_isrss));
  Store_field (res, 6, Val64(ru.ru_minflt));
  Store_field (res, 7, Val64(ru.ru_majflt));
  Store_field (res, 8, Val64(ru.ru_nswap));
  Store_field (res, 9, Val64(ru.ru_inblock));
  Store_field (res, 10, Val64(ru.ru_oublock));
  Store_field (res, 11, Val64(ru.ru_msgsnd));
  Store_field (res, 12, Val64(ru.ru_msgrcv));
  Store_field (res, 13, Val64(ru.ru_nsignals));
  Store_field (res, 14, Val64(ru.ru_nvcsw));
  Store_field (res, 15, Val64(ru.ru_nivcsw));

  CAMLreturn(res);
}

CAMLprim value vmmanage_sysctl_ifcount (value unit) {
  CAMLparam1(unit);
  int data = 0;
  size_t dlen = 0;
  int name[5];

  name[0] = CTL_NET;
  name[1] = PF_LINK;
  name[2] = NETLINK_GENERIC;
  name[3] = IFMIB_SYSTEM;
  name[4] = IFMIB_IFCOUNT;
  dlen = sizeof(data);

  if (sysctl(name, nitems(name), &data, &dlen, NULL, 0) != 0)
    uerror("sysctl", Nothing);

  CAMLreturn(Val_long(data));
}

CAMLprim value vmmanage_sysctl_ifdata (value num) {
  CAMLparam1(num);
  CAMLlocal1(res);
  size_t datalen;
  int name[6];
  struct ifmibdata data;

  name[0] = CTL_NET;
  name[1] = PF_LINK;
  name[2] = NETLINK_GENERIC;
  name[3] = IFMIB_IFDATA;
  name[4] = Int_val(num);
  name[5] = IFDATA_GENERAL;
  datalen = sizeof(data);

  if (sysctl(name, nitems(name), &data, &datalen, NULL, 0) != 0)
    uerror("sysctl", Nothing);

  res = caml_alloc(18, 0);
  Store_field(res, 0, caml_copy_string(data.ifmd_name));
  Store_field(res, 1, Val32(data.ifmd_flags));
  Store_field(res, 2, Val32(data.ifmd_snd_len));
  Store_field(res, 3, Val32(data.ifmd_snd_maxlen));
  Store_field(res, 4, Val32(data.ifmd_snd_drops));
  Store_field(res, 5, Val32(data.ifmd_data.ifi_mtu));
  Store_field(res, 6, Val64(data.ifmd_data.ifi_baudrate));
  Store_field(res, 7, Val64(data.ifmd_data.ifi_ipackets));
  Store_field(res, 8, Val64(data.ifmd_data.ifi_ierrors));
  Store_field(res, 9, Val64(data.ifmd_data.ifi_opackets));
  Store_field(res, 10, Val64(data.ifmd_data.ifi_oerrors));
  Store_field(res, 11, Val64(data.ifmd_data.ifi_collisions));
  Store_field(res, 12, Val64(data.ifmd_data.ifi_ibytes));
  Store_field(res, 13, Val64(data.ifmd_data.ifi_obytes));
  Store_field(res, 14, Val64(data.ifmd_data.ifi_imcasts));
  Store_field(res, 15, Val64(data.ifmd_data.ifi_omcasts));
  Store_field(res, 16, Val64(data.ifmd_data.ifi_iqdrops));
  Store_field(res, 17, Val64(data.ifmd_data.ifi_oqdrops));

  CAMLreturn(res);
}
#else /* FreeBSD */

/* stub symbols for OS currently not supported */

CAMLprim value vmmanage_sysctl_rusage (value pid_r) {
  CAMLparam1(pid_r);
  uerror("sysctl", Nothing);
}

CAMLprim value vmmanage_sysctl_ifcount (value unit) {
  CAMLparam1(unit);
  uerror("sysctl", Nothing);
}

CAMLprim value vmmanage_sysctl_ifdata (value num) {
  CAMLparam1(num);
  uerror("sysctl", Nothing);
}

#endif