/*
 * Copyright 2016 The Cartographer 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 "cartographer/common/time.h"

#include <time.h>

#include <cerrno>
#include <cstring>
#include <string>

#include "glog/logging.h"

namespace cartographer {
namespace common {

Duration FromSeconds(const double seconds) {
  return std::chrono::duration_cast<Duration>(
      std::chrono::duration<double>(seconds));
}

double ToSeconds(const Duration duration) {
  return std::chrono::duration_cast<std::chrono::duration<double>>(duration)
      .count();
}

double ToSeconds(const std::chrono::steady_clock::duration duration) {
  return std::chrono::duration_cast<std::chrono::duration<double>>(duration)
      .count();
}

Time FromUniversal(const int64 ticks) { return Time(Duration(ticks)); }

int64 ToUniversal(const Time time) { return time.time_since_epoch().count(); }

std::ostream& operator<<(std::ostream& os, const Time time) {
  os << std::to_string(ToUniversal(time));
  return os;
}

common::Duration FromMilliseconds(const int64 milliseconds) {
  return std::chrono::duration_cast<Duration>(
      std::chrono::milliseconds(milliseconds));
}

double GetThreadCpuTimeSeconds() {
#ifndef WIN32
  struct timespec thread_cpu_time;
  CHECK(clock_gettime(CLOCK_THREAD_CPUTIME_ID, &thread_cpu_time) == 0)
      << std::strerror(errno);
  return thread_cpu_time.tv_sec + 1e-9 * thread_cpu_time.tv_nsec;
#else
  return 0.;
#endif
}

}  // namespace common
}  // namespace cartographer