/*
 *
 * Copyright 2018 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <grpc/support/port_platform.h>

#ifdef GPR_WINDOWS

#include <windows.h>
#include <cstdint>

#include "src/cpp/server/load_reporter/get_cpu_stats.h"

namespace grpc {
namespace load_reporter {

namespace {

uint64_t FiletimeToInt(const FILETIME& ft) {
  ULARGE_INTEGER i;
  i.LowPart = ft.dwLowDateTime;
  i.HighPart = ft.dwHighDateTime;
  return i.QuadPart;
}

}  // namespace

std::pair<uint64_t, uint64_t> GetCpuStatsImpl() {
  uint64_t busy = 0, total = 0;
  FILETIME idle, kernel, user;
  if (GetSystemTimes(&idle, &kernel, &user) != 0) {
    total = FiletimeToInt(kernel) + FiletimeToInt(user);
    busy = total - FiletimeToInt(idle);
  }
  return std::make_pair(busy, total);
}

}  // namespace load_reporter
}  // namespace grpc

#endif  // GPR_WINDOWS