/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the Collabora Office project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you 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 .
 */

#include <sal/config.h>

#include <algorithm>

#if defined(_WIN32)
#if !defined WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <mmsystem.h>
#elif defined UNX
#include <sys/time.h>
#include <unistd.h>
#endif

#include <time.h>
#ifdef __MACH__
#include <mach/clock.h>
#include <mach/mach.h>
#include <mach/mach_time.h>
#endif

#include <osl/time.h>
#include <rtl/math.hxx>
#include <tools/time.hxx>
#include <com/sun/star/util/DateTime.hpp>

#include <systemdatetime.hxx>

namespace tools {

Time::Time( TimeInitSystem )
{
    if ( !GetSystemDateTime( nullptr, &nTime ) )
        nTime = 0;
}

Time::Time( sal_uInt32 nHour, sal_uInt32 nMin, sal_uInt32 nSec, sal_uInt64 nNanoSec )
{
    // normalize time
    if (nNanoSec >= nanoSecPerSec)
    {
        nSec += nNanoSec / nanoSecPerSec;
        nNanoSec %= nanoSecPerSec;
    }
    if (nSec >= secondPerMinute)
    {
        nMin += nSec / secondPerMinute;
        nSec %= secondPerMinute;
    }
    if (nMin >= minutePerHour)
    {
        nHour += nMin / minutePerHour;
        nMin %= minutePerHour;
    }

    // 922337 * HOUR_MASK = 9223370000000000000 largest possible value, 922338
    // would be -9223364073709551616.
    assert(HOUR_MASK * nHour >= 0 && "use tools::Duration with days instead!");
    if (HOUR_MASK * nHour < 0)
        nHour = 922337;

    // But as is, GetHour() retrieves only sal_uInt16. Though retrieving in
    // nanoseconds or milliseconds might be possible this is all crap.
    assert(nHour <= SAL_MAX_UINT16 && "use tools::Duration with days instead!");
    if (nHour > SAL_MAX_UINT16)
        nHour = SAL_MAX_UINT16;

    // construct time
    nTime = assemble(nHour, nMin, nSec, nNanoSec);
}
Time::Time( const css::util::Time &_rTime )
    : Time(_rTime.Hours, _rTime.Minutes, _rTime.Seconds, _rTime.NanoSeconds)
{
}
Time::Time( const css::util::DateTime &_rDateTime )
    : Time(_rDateTime.Hours, _rDateTime.Minutes, _rDateTime.Seconds, _rDateTime.NanoSeconds)
{
}

// static
sal_Int64 tools::Time::assemble(sal_uInt32 h, sal_uInt32 m, sal_uInt32 s, sal_uInt64 ns)
{
    return ns + s * SEC_MASK + m * MIN_MASK + h * HOUR_MASK;
}

void tools::Time::SetHour( sal_uInt16 nNewHour )
{
    nTime = GetSign() * assemble(nNewHour, GetMin(), GetSec(), GetNanoSec());
}

void tools::Time::SetMin( sal_uInt16 nNewMin )
{
    // no overflow
    nTime = GetSign() * assemble(GetHour(), nNewMin % minutePerHour, GetSec(), GetNanoSec());
}

void tools::Time::SetSec( sal_uInt16 nNewSec )
{
    // no overflow
    nTime = GetSign() * assemble(GetHour(), GetMin(), nNewSec % secondPerMinute, GetNanoSec());
}

void tools::Time::SetNanoSec( sal_uInt32 nNewNanoSec )
{
    // no overflow
    nTime = GetSign() * assemble(GetHour(), GetMin(), GetSec(), nNewNanoSec % nanoSecPerSec);
}

sal_Int64 tools::Time::GetNSFromTime() const
{
    return GetSign() *
           ( GetNanoSec() +
             GetSec() * nanoSecPerSec +
             GetMin() * nanoSecPerMinute +
             GetHour() * nanoSecPerHour );
}

void tools::Time::MakeTimeFromNS( sal_Int64 nNS )
{
    short nSign;
    if ( nNS < 0 )
    {
        nNS *= -1;
        nSign = -1;
    }
    else
        nSign = 1;

    tools::Time aTime(0, 0, 0, nNS);
    SetTime( aTime.GetTime() * nSign );
}

sal_Int32 tools::Time::GetMSFromTime() const
{
    return GetNSFromTime() / nanoPerMilli;
}

void tools::Time::MakeTimeFromMS( sal_Int32 nMS )
{
    MakeTimeFromNS(nMS * nanoPerMilli);
}

double tools::Time::GetTimeInDays() const
{
    return GetNSFromTime() / double(nanoSecPerDay);
}

// static
void tools::Time::GetClock( double fTimeInDays,
                            sal_uInt16& nHour, sal_uInt16& nMinute, sal_uInt16& nSecond,
                            double& fFractionOfSecond, int nFractionDecimals )
{
    const double fTime = fTimeInDays - rtl::math::approxFloor(fTimeInDays); // date part absent

    // If 0 then full day (or no day), shortcut.
    // If < 0 then approxFloor() effectively returned the ceiling (note this
    // also holds for negative fTimeInDays values) because of a near identical
    // value, shortcut this to a full day as well.
    // If >= 1.0 (actually == 1.0) then fTimeInDays is a negative small value
    // not significant for a representable time and approxFloor() returned -1,
    // shortcut to 0:0:0, otherwise it would become 24:0:0.
    if (fTime <= 0.0 || fTime >= 1.0)
    {
        nHour = nMinute = nSecond = 0;
        fFractionOfSecond = 0.0;
        return;
    }

    // In seconds, including milli and nano.
    const double fRawSeconds = fTime * tools::Time::secondPerDay;

    // Round to nanoseconds most, which is the highest resolution this could be
    // influenced by, but if the original value included a date round to at
    // most 14 significant digits (including adding 4 for *86400), otherwise we
    // might end up with a fake precision of h:m:s.999999986 which in fact
    // should had been h:m:s+1
    // BUT, leave at least 2 decimals to round. Which shouldn't be a problem in
    // practice because class Date can calculate only 8-digit days for it's
    // sal_Int16 year range, which exactly leaves us with 14-4-8=2.
    int nDec = 9;
    const double fAbsTimeInDays = fabs( fTimeInDays);
    if (fAbsTimeInDays >= 1.0)
    {
        const int nDig = static_cast<int>(ceil( log10( fAbsTimeInDays)));
        nDec = std::clamp( 10 - nDig, 2, 9 );
    }
    double fSeconds = rtl::math::round( fRawSeconds, nDec);

    // If this ended up as a full day the original value was very very close
    // but not quite. Take that.
    if (fSeconds >= tools::Time::secondPerDay)
        fSeconds = fRawSeconds;

    // Now do not round values (specifically not up), but truncate to the next
    // magnitude, so 23:59:59.99 is still 23:59:59 and not 24:00:00 (or even
    // 00:00:00 which Excel does).
    nHour = fSeconds / tools::Time::secondPerHour;
    fSeconds -= nHour * tools::Time::secondPerHour;
    nMinute = fSeconds / tools::Time::secondPerMinute;
    fSeconds -= nMinute * tools::Time::secondPerMinute;
    nSecond = fSeconds;
    fSeconds -= nSecond;

    assert(fSeconds < 1.0);     // or back to the drawing board...

    if (nFractionDecimals > 0)
    {
        // Do not simply round the fraction, otherwise .999 would end up as .00
        // again. Truncate instead if rounding would round up into an integer
        // value.
        fFractionOfSecond = rtl::math::round( fSeconds, nFractionDecimals);
        if (fFractionOfSecond >= 1.0)
            fFractionOfSecond = rtl::math::pow10Exp( std::trunc(
                        rtl::math::pow10Exp( fSeconds, nFractionDecimals)), -nFractionDecimals);
    }
    else
        fFractionOfSecond = fSeconds;
}

Time& tools::Time::operator +=( const tools::Time& rTime )
{
    MakeTimeFromNS(GetNSFromTime() + rTime.GetNSFromTime());
    return *this;
}

Time& tools::Time::operator -=( const tools::Time& rTime )
{
    MakeTimeFromNS(GetNSFromTime() - rTime.GetNSFromTime());
    return *this;
}

Time operator +( const tools::Time& rTime1, const tools::Time& rTime2 )
{
    tools::Time result(rTime1);
    return result += rTime2;
}

Time operator -( const tools::Time& rTime1, const tools::Time& rTime2 )
{
    tools::Time result(rTime1);
    return result -= rTime2;
}

bool tools::Time::IsEqualIgnoreNanoSec( const tools::Time& rTime ) const
{
    return nTime / SEC_MASK == rTime.nTime / SEC_MASK;
}

Time tools::Time::GetUTCOffset()
{
    static sal_uInt64   nCacheTicks = 0;
    static sal_Int32    nCacheSecOffset = -1;
    sal_uInt64          nTicks = tools::Time::GetSystemTicks();

    // determine value again if needed
    if ( (nCacheSecOffset == -1)            ||
         ((nTicks - nCacheTicks) > 360000)  ||
         ( nTicks < nCacheTicks ) // handle overflow
         )
    {
        TimeValue utcTv;
        TimeValue localTv;
        if (osl_getSystemTime(&utcTv) && osl_getLocalTimeFromSystemTime(&utcTv, &localTv))
        {
            nCacheTicks = nTicks;
            nCacheSecOffset = (static_cast<sal_Int64>(localTv.Seconds)
                               - static_cast<sal_Int64>(utcTv.Seconds)) / 60;
        }
        else
        {
            nCacheSecOffset = 0;
        }
    }

    sal_Int32 nTempTime = abs( nCacheSecOffset );
    tools::Time aTime( 0, static_cast<sal_uInt16>(nTempTime) );
    if ( nCacheSecOffset < 0 )
        aTime = -aTime;
    return aTime;
}

sal_uInt64 tools::Time::GetSystemTicks()
{
    return tools::Time::GetMonotonicTicks() / 1000;
}

#ifdef _WIN32
static LARGE_INTEGER initPerformanceFrequency()
{
    LARGE_INTEGER nTicksPerSecond = { 0, 0 };
    if (!QueryPerformanceFrequency(&nTicksPerSecond))
        nTicksPerSecond.QuadPart = 0;
    return nTicksPerSecond;
}
#endif

sal_uInt64 tools::Time::GetMonotonicTicks()
{
#ifdef _WIN32
    static const LARGE_INTEGER nTicksPerSecond = initPerformanceFrequency();
    if (nTicksPerSecond.QuadPart > 0)
    {
        LARGE_INTEGER nPerformanceCount;
        QueryPerformanceCounter(&nPerformanceCount);
        return static_cast<sal_uInt64>(
            ( nPerformanceCount.QuadPart * 1000 * 1000 ) / nTicksPerSecond.QuadPart );
    }
    else
    {
        return static_cast<sal_uInt64>( timeGetTime() * 1000 );
    }
#else
    sal_uInt64 nMicroSeconds;
#ifdef __MACH__
    static mach_timebase_info_data_t info = { 0, 0 };
    if ( 0 == info.numer )
        mach_timebase_info( &info );
    nMicroSeconds = mach_absolute_time() * static_cast<double>(info.numer / info.denom) / 1000;
#else
#if defined(_POSIX_TIMERS)
    struct timespec currentTime;
    clock_gettime( CLOCK_MONOTONIC, &currentTime );
    nMicroSeconds
        = static_cast<sal_uInt64>(currentTime.tv_sec) * 1000 * 1000 + currentTime.tv_nsec / 1000;
#else
    struct timeval currentTime;
    gettimeofday( &currentTime, nullptr );
    nMicroSeconds = static_cast<sal_uInt64>(currentTime.tv_sec) * 1000 * 1000 + currentTime.tv_usec;
#endif
#endif // __MACH__
    return nMicroSeconds;
#endif // _WIN32
}

} /* namespace tools */

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