/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/syscall-nt.internal.h"
#include "libc/intrin/strace.h"
#include "libc/nt/enum/processcreationflags.h"
#include "libc/nt/errors.h"
#include "libc/nt/process.h"
#include "libc/nt/runtime.h"
#include "libc/proc/proc.internal.h"
#include "libc/sysv/consts/prio.h"
#include "libc/sysv/errfuns.h"

textwindows int sys_getpriority_nt(int which, unsigned pid) {

  if (which != PRIO_PROCESS) {
    return einval();
  }

  int64_t handle;
  if (!(handle = __proc_handle(pid))) {
    return esrch();
  }

  uint32_t tier;
  switch ((tier = GetPriorityClass(handle))) {
    case kNtRealtimePriorityClass:
      return -16;
      break;
    case kNtHighPriorityClass:
      return -10;
      break;
    case kNtAboveNormalPriorityClass:
      return -5;
      break;
    case kNtNormalPriorityClass:
      return 0;
      break;
    case kNtBelowNormalPriorityClass:
      return 5;
      break;
    case kNtIdlePriorityClass:
      return 15;
      break;
    case 0:
      STRACE("GetPriorityClass() failed with %d", GetLastError());
      if (GetLastError() == kNtErrorInvalidHandle) {
        return esrch();
      } else {
        return eperm();
      }
    default:
      STRACE("unknown win32 priority class %d", tier);
      return 0;
  }
}