/*=========================================================================

   Library: iMSTK

   Copyright (c) Kitware, Inc. & Center for Modeling, Simulation,
   & Imaging in Medicine, Rensselaer Polytechnic Institute.

   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.txt

   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 "imstkTimer.h"

namespace imstk
{
const double
StopWatch::wcTimerConstants[] = {
    1.0,
    1 / 1000.0,
    1 / (1000.0*60.0),
    1 / (1000.0*60.0 * 60)
};

const double
CpuTimer::cpuTimerConstants[] = {
    1000.0 / CLOCKS_PER_SEC,
    1.0 / CLOCKS_PER_SEC,
    1.0 / (CLOCKS_PER_SEC * 60.0),
    1.0 / (CLOCKS_PER_SEC * 60.0 * 60.0)
};

void
StopWatch::start()
{
    wallClockTimeKeeper = std::chrono::high_resolution_clock::now();
    this->state = TimerState::started;
}

void
StopWatch::stop()
{
    this->storeLap();
    this->state = TimerState::stopped;
}

void
StopWatch::reset()
{
    lapTimes.clear();
    this->state = TimerState::stopped;
}

double
StopWatch::getTotalLapTimes()
{
    double totalTime = 0.0;
    for (const auto& timeChunk : lapTimes)
    {
        totalTime += timeChunk;
    }
    return totalTime;
}

void
StopWatch::storeLap(std::string const& lapName)
{
    if (this->lapTimes.size() > 0)
    {
        this->lapTimes.push_back(this->getTimeElapsed() - *this->lapTimes.end());
    }
    else
    {
        this->lapTimes.push_back(this->getTimeElapsed());
    }

    if (lapName == "noName")
    {
        this->lapNames.push_back("Lap " + std::to_string(lapNames.size()));
    }
    else
    {
        this->lapNames.push_back(lapName);
    }

    this->state = TimerState::stopped;
}

void
StopWatch::storeLap()
{
    this->storeLap(std::string("noName"));
}

void
StopWatch::printLapTimes()
{
    LOG(INFO) << "Lap times:";
    for (int i = 0; i < this->lapTimes.size(); ++i)
    {
        LOG(INFO) << "\t" << this->lapNames.at(i) << ": " << this->lapTimes.at(i) << "ms";
    }
}

std::string
StopWatch::getTimeAndDate()
{
    time_t now = time(0);
    return std::string(asctime(gmtime(&now)));
}

void
StopWatch::printTimeElapsed(std::string const& name /* = std::string("noName")*/,
                            const TimeUnitType unitType /*= TimeUnitType::milliSeconds*/)
{
    switch (unitType)
    {
    case TimeUnitType::milliSeconds:
        LOG(INFO) << name << ": " << this->getTimeElapsed(unitType) << " ms.";
        break;

    case TimeUnitType::seconds:
        LOG(INFO) << name << ": " << this->getTimeElapsed(unitType) << " sec.";
        break;

    case TimeUnitType::minutes:
        LOG(INFO) << name << ": " << this->getTimeElapsed(unitType) << " min.";
        break;

    case TimeUnitType::hours:
        LOG(INFO) << name << ": " << this->getTimeElapsed(unitType) << " hrs.";
        break;

    default:
        LOG(WARNING) << "Type of the time integrator not identified!";
        break;
    }
}


double
StopWatch::getTimeElapsed(const TimeUnitType unitType /*= TimeUnitType::milliSeconds*/)
{
    return std::chrono::duration<double, std::milli>
           (std::chrono::high_resolution_clock::now() - wallClockTimeKeeper).count()*
           wcTimerConstants[(int)unitType];
}

double
CpuTimer::getTimeElapsed(const TimeUnitType unitType /*= TimeUnitType::milliSeconds*/)
{
    return (std::clock() - cpuTimeKeeper)*cpuTimerConstants[(int)unitType];
}

void
UPSCounter::reset()
{
    m_timer->reset();
    m_accumulatedTimer = 0.;
    m_ups = 0;
    m_updateCount = 0;
}

void
UPSCounter::setEndPointOfUpdate()
{
    m_accumulatedTimer += m_timer->getTimeElapsed(StopWatch::TimeUnitType::milliSeconds);
    m_updateCount++;

    if (m_accumulatedTimer > 1000.)
    {
        m_ups = m_updateCount;
        m_updateCount = 0;
        m_accumulatedTimer = 0.;
    }
}
}
