/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2017     Statoil ASA
//
//  ResInsight is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
//  WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE.
//
//  See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#include "RiaQDateTimeTools.h"

#include <QDateTime>
#include <QLocale>
#include <QString>

#include "cafPdmUiItem.h"

#include <cvfAssert.h>

#include <cmath>
#include <ctime>

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_DAY      = DateTimeSpan( 0, 0, 1 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_WEEK     = DateTimeSpan( 0, 0, 7 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_MONTH    = DateTimeSpan( 0, 1, 0 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_QUARTER  = DateTimeSpan( 0, 3, 0 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_HALFYEAR = DateTimeSpan( 0, 6, 0 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_YEAR     = DateTimeSpan( 1, 0, 0 );
const DateTimeSpan RiaQDateTimeTools::TIMESPAN_DECADE   = DateTimeSpan( 10, 0, 0 );

namespace caf
{
// clang-format off

template <>
void caf::AppEnum<RiaQDateTimeTools::DateFormatComponents>::setUp()
{
    addItem( RiaQDateTimeTools::DATE_FORMAT_NONE,           "NO_DATE",          "No Date" );
    addItem( RiaQDateTimeTools::DATE_FORMAT_YEAR,           "YEAR",             "Year Only" );
    addItem( RiaQDateTimeTools::DATE_FORMAT_YEAR_MONTH,     "YEAR_MONTH",       "Year and Month" );
    addItem( RiaQDateTimeTools::DATE_FORMAT_YEAR_MONTH_DAY, "YEAR_MONTH_DAY",   "Year, Month and Day" );
    setDefault( RiaQDateTimeTools::DATE_FORMAT_YEAR_MONTH_DAY );
}

template <>
void caf::AppEnum<RiaQDateTimeTools::TimeFormatComponents>::setUp()
{
    addItem( RiaQDateTimeTools::TimeFormatComponents::TIME_FORMAT_NONE,               "NO_TIME",              "No Time of Day" );
    addItem( RiaQDateTimeTools::TimeFormatComponents::TIME_FORMAT_HOUR,               "HOUR",                 "Hour Only" );
    addItem( RiaQDateTimeTools::TimeFormatComponents::TIME_FORMAT_HOUR_MINUTE,        "HOUR_MINUTE",          "Hour and Minute" );
    addItem( RiaQDateTimeTools::TimeFormatComponents::TIME_FORMAT_HOUR_MINUTE_SECOND, "HOUR_MINUTE_SECONDS",  "Hour, Minutes and Seconds" );
    setDefault( RiaQDateTimeTools::TimeFormatComponents::TIME_FORMAT_NONE );
}

template <>
void caf::AppEnum<RiaQDateTimeTools::DateTimePeriod>::setUp()
{
    addItem( RiaQDateTimeTools::DateTimePeriod::NONE,       "NONE",     "None" );
    addItem( RiaQDateTimeTools::DateTimePeriod::DAY,        "DAY",      "Day" );
    addItem( RiaQDateTimeTools::DateTimePeriod::WEEK,       "WEEK",     "Week" );
    addItem( RiaQDateTimeTools::DateTimePeriod::MONTH,      "MONTH",    "Month" );
    addItem( RiaQDateTimeTools::DateTimePeriod::QUARTER,    "QUARTER",  "Quarter" );
    addItem( RiaQDateTimeTools::DateTimePeriod::HALFYEAR,   "HALFYEAR", "Half Year" );
    addItem( RiaQDateTimeTools::DateTimePeriod::YEAR,       "YEAR",     "Year" );
    addItem( RiaQDateTimeTools::DateTimePeriod::DECADE,     "DECADE",   "Decade" );
    setDefault( RiaQDateTimeTools::DateTimePeriod::NONE );
}

// clang-format on
} // namespace caf

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
Qt::TimeSpec RiaQDateTimeTools::currentTimeSpec()
{
    return Qt::UTC;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
quint64 RiaQDateTimeTools::secondsInDay()
{
    return 60 * 60 * 24;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
quint64 RiaQDateTimeTools::secondsInYear()
{
    return 60 * 60 * 24 * 365;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::fromString( const QString& dateString, const QString& format )
{
    QDateTime dt = QDateTime::fromString( dateString, format );
    dt.setTimeSpec( currentTimeSpec() );

    return dt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::fromYears( double years )
{
    double yearsAfterEpoch = years - 1970.0;

    QDateTime dt = RiaQDateTimeTools::epoch();

    return RiaQDateTimeTools::addYears( dt, yearsAfterEpoch );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::fromTime_t( time_t t )
{
    auto qdt = createUtcDateTime();
    qdt.setSecsSinceEpoch( t );
    return qdt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::addMSecs( const QDateTime& dt, double msecs )
{
    return dt.addMSecs( msecs );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::addDays( const QDateTime& dt, double days )
{
    double integerPart  = 0.0;
    double fractionPart = 0.0;

    fractionPart = modf( days, &integerPart );

    QDateTime tmp = dt.addDays( integerPart );
    tmp           = tmp.addSecs( fractionPart * RiaQDateTimeTools::secondsInDay() );

    return tmp;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::addYears( const QDateTime& dt, double years )
{
    double integerPart  = 0.0;
    double fractionPart = 0.0;

    fractionPart = modf( years, &integerPart );

    QDateTime tmp = dt.addYears( integerPart );
    tmp           = tmp.addSecs( fractionPart * RiaQDateTimeTools::secondsInYear() );

    return tmp;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::addSpan( const QDateTime& dt, DateTimeSpan span )
{
    return createUtcDateTime( dt ).addYears( span.years() ).addMonths( span.months() ).addDays( span.days() );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::subtractSpan( const QDateTime& dt, DateTimeSpan span )
{
    return createUtcDateTime( dt ).addYears( -span.years() ).addMonths( -span.months() ).addDays( -span.days() );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::addPeriod( const QDateTime& dt, RiaQDateTimeTools::DateTimePeriod period )
{
    return addSpan( dt, timeSpan( period ) );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::subtractPeriod( const QDateTime& dt, RiaQDateTimeTools::DateTimePeriod period )
{
    return subtractSpan( dt, timeSpan( period ) );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::epoch()
{
    // NB: Not able to use QDateTime::fromMSecsSinceEpoch as this was introduced in Qt 4.7

    QDateTime dt;
    dt.setDate( QDate( 1970, 1, 1 ) );
    dt.setTimeSpec( currentTimeSpec() );

    return dt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::createUtcDateTime()
{
    auto qdt = QDateTime();
    qdt.setTimeSpec( currentTimeSpec() );
    return qdt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::createUtcDateTime( const QDate& date )
{
    auto qdt = QDateTime( date );
    qdt.setTimeSpec( currentTimeSpec() );
    return qdt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::createUtcDateTime( const QDate& date, const QTime& time )
{
    auto qdt = QDateTime( date, time, currentTimeSpec() );
    return qdt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::createUtcDateTime( const QDateTime& dt )
{
    auto qdt = QDateTime( dt );
    qdt.setTimeSpec( currentTimeSpec() );
    return qdt;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
bool RiaQDateTimeTools::lessThan( const QDateTime& dt1, const QDateTime& dt2 )
{
    // dt1 < dt2
    return dt1.secsTo( dt2 ) > 0;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
const DateTimeSpan RiaQDateTimeTools::timeSpan( RiaQDateTimeTools::DateTimePeriod period )
{
    switch ( period )
    {
        case RiaQDateTimeTools::DateTimePeriod::DAY:
            return TIMESPAN_DAY;
        case RiaQDateTimeTools::DateTimePeriod::WEEK:
            return TIMESPAN_WEEK;
        case RiaQDateTimeTools::DateTimePeriod::MONTH:
            return TIMESPAN_MONTH;
        case RiaQDateTimeTools::DateTimePeriod::QUARTER:
            return TIMESPAN_QUARTER;
        case RiaQDateTimeTools::DateTimePeriod::HALFYEAR:
            return TIMESPAN_HALFYEAR;
        case RiaQDateTimeTools::DateTimePeriod::YEAR:
            return TIMESPAN_YEAR;
        case RiaQDateTimeTools::DateTimePeriod::DECADE:
            return TIMESPAN_DECADE;
    }
    CVF_ASSERT( false );
    return DateTimeSpan();
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QDateTime RiaQDateTimeTools::truncateTime( const QDateTime& dt, RiaQDateTimeTools::DateTimePeriod period )
{
    int y   = dt.date().year();
    int m   = dt.date().month();
    int d   = dt.date().day();
    int dow = dt.date().dayOfWeek();

    switch ( period )
    {
        case RiaQDateTimeTools::DateTimePeriod::DAY:
            return createUtcDateTime( QDate( y, m, d ) );
        case RiaQDateTimeTools::DateTimePeriod::WEEK:
            return createUtcDateTime( QDate( y, m, d ).addDays( -dow + 1 ) );
        case RiaQDateTimeTools::DateTimePeriod::MONTH:
            return createUtcDateTime( QDate( y, m, 1 ) );
        case RiaQDateTimeTools::DateTimePeriod::QUARTER:
            return createUtcDateTime( QDate( y, ( ( m - 1 ) / 3 ) * 3 + 1, 1 ) );
        case RiaQDateTimeTools::DateTimePeriod::HALFYEAR:
            return createUtcDateTime( QDate( y, ( ( m - 1 ) / 6 ) * 6 + 1, 1 ) );
        case RiaQDateTimeTools::DateTimePeriod::YEAR:
            return createUtcDateTime( QDate( y, 1, 1 ) );
        case RiaQDateTimeTools::DateTimePeriod::DECADE:
            return createUtcDateTime( QDate( ( y / 10 ) * 10, 1, 1 ) );
    }
    CVF_ASSERT( false );
    return createUtcDateTime();
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<RiaQDateTimeTools::DateTimePeriod> RiaQDateTimeTools::dateTimePeriods()
{
    std::vector<DateTimePeriod> allPeriods;

    for ( size_t i = 0; i < DateTimePeriodEnum::size(); i++ )
    {
        allPeriods.push_back( DateTimePeriodEnum::fromIndex( i ) );
    }

    return allPeriods;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::dateTimePeriodName( RiaQDateTimeTools::DateTimePeriod period )
{
    return DateTimePeriodEnum::uiText( period );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::toStringUsingApplicationLocale( const QDateTime& dt, const QString& format )
{
    // Default application locale is set in RiaMain
    // QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
    //
    // QDate/QDateTime use system locale for toString() functions

    QLocale defaultApplicationLocale;

    return defaultApplicationLocale.toString( dt, format );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::createTimeFormatStringFromDates( const std::vector<QDateTime>& dates )
{
    bool hasHoursAndMinutesInTimesteps = false;
    bool hasSecondsInTimesteps         = false;
    bool hasMillisecondsInTimesteps    = false;

    for ( size_t i = 0; i < dates.size(); i++ )
    {
        if ( dates[i].time().msec() != 0.0 )
        {
            hasMillisecondsInTimesteps    = true;
            hasSecondsInTimesteps         = true;
            hasHoursAndMinutesInTimesteps = true;
            break;
        }
        else if ( dates[i].time().second() != 0.0 )
        {
            hasHoursAndMinutesInTimesteps = true;
            hasSecondsInTimesteps         = true;
        }
        else if ( dates[i].time().hour() != 0.0 || dates[i].time().minute() != 0.0 )
        {
            hasHoursAndMinutesInTimesteps = true;
        }
    }

    QString formatString = dateFormatString();
    if ( hasHoursAndMinutesInTimesteps )
    {
        formatString += " - hh:mm";
        if ( hasSecondsInTimesteps )
        {
            formatString += ":ss";
            if ( hasMillisecondsInTimesteps )
            {
                formatString += ".zzz";
            }
        }
    }

    return formatString;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::dateFormatString()
{
    return "dd.MMM yyyy";
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<QString> RiaQDateTimeTools::supportedDateFormats()
{
    std::vector<QString> dateFormats;

    // See enum DateFormatComponents in header
    // The semi-colon separated components are:
    // DATE_FORMAT_YEAR, ..YEAR_MONTH, ..YEAR_MONTH_DAY
    dateFormats.push_back( "yyyy;yyyy-MM;yyyy-MM-dd" );
    dateFormats.push_back( "yyyy;MMM yyyy;dd. MMM yyyy" );
    dateFormats.push_back( "yyyy;MMM yyyy;MMM dd. yyyy" );
    dateFormats.push_back( "yyyy;MM/yyyy;dd/MM/yyyy" );
    dateFormats.push_back( "yyyy;M/yyyy;d/M/yyyy" );
    dateFormats.push_back( "yyyy;M/yyyy;M/d/yyyy" );
    dateFormats.push_back( "yy;M/yy;d/M/yy" );
    dateFormats.push_back( "yy;M/yy;M/d/yy" );
    dateFormats.push_back( "yyyy;MM-yyyy;dd-MM-yyyy" );
    dateFormats.push_back( "yyyy;MM.yyyy;dd.MM.yyyy" );
    dateFormats.push_back( "yyyy;MM-yyyy;MM-dd-yyyy" );
    dateFormats.push_back( "yyyy;MM.yyyy;MM.dd.yyyy" );
    dateFormats.push_back( "yy;MM-yy;dd-MM-yy" );
    dateFormats.push_back( "yy;MM-yy;MM-dd-yy" );

    return dateFormats;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<QString> RiaQDateTimeTools::supportedTimeFormats()
{
    std::vector<QString> timeFormats;

    // See enum TimeFormatComponents in header
    // The semi-colon separated components are:
    // TIME_FORMAT_HOUR, ..HOUR_MINUTE, ..HOUR_MINUTE_SECOND and ..HOUR_MINUTE_MILLISECOND
    timeFormats.push_back( "HH;HH:mm;HH:mm:ss;HH:mm:ss.zzz" );
    timeFormats.push_back( "H;H:mm;H:mm:ss;H:mm:ss.zzz" );
    timeFormats.push_back( "hh AP;hh:mm AP;hh:mm:ss AP;hh:mm:ss.zzz AP" );
    timeFormats.push_back( "h AP;h:mm AP;h:mm:ss AP;h:mm:ss.zzz AP" );

    return timeFormats;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::dateFormatString( const QString& fullDateFormat, DateFormatComponents dateComponents )
{
    if ( dateComponents == DATE_FORMAT_NONE ) return "";

    QStringList allVariants = fullDateFormat.split( ";" );
    if ( static_cast<int>( dateComponents ) < allVariants.size() )
    {
        return allVariants[dateComponents];
    }
    CVF_ASSERT( false && "Date format string is malformed" );
    return "";
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QString RiaQDateTimeTools::timeFormatString( const QString& fullTimeFormat, TimeFormatComponents timeComponents )
{
    if ( timeComponents == TimeFormatComponents::TIME_FORMAT_NONE ) return "";

    QStringList allVariants = fullTimeFormat.split( ";" );
    if ( static_cast<int>( timeComponents ) < allVariants.size() )
    {
        return allVariants[static_cast<int>( timeComponents )];
    }
    CVF_ASSERT( false && "Time format string is malformed" );
    return "";
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QList<caf::PdmOptionItemInfo> RiaQDateTimeTools::createOptionItems( const std::vector<time_t>& timeSteps )
{
    QList<caf::PdmOptionItemInfo> options;

    std::vector<QDateTime> dateTimes;
    for ( time_t timeT : timeSteps )
    {
        QDateTime dateTime = RiaQDateTimeTools::fromTime_t( timeT );

        dateTimes.push_back( dateTime );
    }

    QString formatString = RiaQDateTimeTools::createTimeFormatStringFromDates( dateTimes );

    for ( size_t i = 0; i < dateTimes.size(); i++ )
    {
        const auto& dt   = dateTimes[i];
        QString     text = RiaQDateTimeTools::toStringUsingApplicationLocale( dt, formatString );
        options.push_back( { text, static_cast<int>( i ) } );
    }

    return options;
}