/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

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

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#undef NANOSEC
#define NANOSEC 1000000000


uint64_t uv_hrtime(void) {
  struct timespec ts;
  clock_gettime(CLOCK_MONOTONIC, &ts);
  return (((uint64_t) ts.tv_sec) * NANOSEC + ts.tv_nsec);
}

void uv_loadavg(double avg[3]) {
  struct loadavg info;
  size_t size = sizeof(info);
  int which[] = {CTL_VM, VM_LOADAVG};

  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) return;

  avg[0] = (double) info.ldavg[0] / info.fscale;
  avg[1] = (double) info.ldavg[1] / info.fscale;
  avg[2] = (double) info.ldavg[2] / info.fscale;
}

int uv_exepath(char* buffer, size_t* size) {
  int mib[4];
  char **argsbuf = NULL;
  char **argsbuf_tmp;
  size_t argsbuf_size = 100U;
  size_t exepath_size;
  pid_t mypid;
  int status = -1;

  if (!buffer || !size) {
    goto out;
  }
  mypid = getpid();
  for (;;) {
    if ((argsbuf_tmp = realloc(argsbuf, argsbuf_size)) == NULL) {
      goto out;
    }
    argsbuf = argsbuf_tmp;
    mib[0] = CTL_KERN;
    mib[1] = KERN_PROC_ARGS;
    mib[2] = mypid;
    mib[3] = KERN_PROC_ARGV;
    if (sysctl(mib, 4, argsbuf, &argsbuf_size, NULL, 0) == 0) {
      break;
    }
    if (errno != ENOMEM) {
      goto out;
    }
    argsbuf_size *= 2U;
  }
  if (argsbuf[0] == NULL) {
    goto out;
  }
  exepath_size = strlen(argsbuf[0]);
  if (exepath_size >= *size) {
    goto out;
  }
  memcpy(buffer, argsbuf[0], exepath_size + 1U);
  *size = exepath_size;
  status = 0;

out:
  free(argsbuf);

  return status;
}

uint64_t uv_get_free_memory(void) {
  struct uvmexp info;
  size_t size = sizeof(info);
  int which[] = {CTL_VM, VM_UVMEXP};

  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) {
    return -1;
  }

  return (uint64_t) info.free * sysconf(_SC_PAGESIZE);
}

uint64_t uv_get_total_memory(void) {
  uint64_t info;
  int which[] = {CTL_HW, HW_PHYSMEM64};
  size_t size = sizeof(info);

  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) {
    return -1;
  }

  return (uint64_t) info;
}