ClickHouse/dbms/src/Functions/FunctionsDateTime.h

#pragma once

#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeDate.h>
#include <DataTypes/DataTypeDateTime.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeString.h>

#include <Columns/ColumnsNumber.h>
#include <Columns/ColumnConst.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnFixedString.h>

#include <Common/typeid_cast.h>

#include <IO/WriteHelpers.h>

#include <Functions/IFunction.h>

#include <common/DateLUT.h>

#include <type_traits>


namespace DB
{

namespace ErrorCodes
{
    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
}

/** Functions for working with date and time.
  *
  * toYear, toMonth, toDayOfMonth, toDayOfWeek, toHour, toMinute, toSecond,
  * toMonday, toStartOfMonth, toStartOfYear, toStartOfMinute, toStartOfFiveMinute
  * toStartOfHour, toTime,
  * now, today, yesterday
  * TODO: makeDate, makeDateTime
  *
  * (toDate - located in FunctionConversion.h file)
  *
  * Return types:
  *  toYear -> UInt16
  *  toMonth, toDayOfMonth, toDayOfWeek, toHour, toMinute, toSecond -> UInt8
  *  toMonday, toStartOfMonth, toStartOfYear -> Date
  *  toStartOfMinute, toStartOfHour, toTime, now -> DateTime
  *
  * And also:
  *
  * timeSlot(EventTime)
  * - rounds the time to half an hour.
  *
  * timeSlots(StartTime, Duration)
  * - for the time interval beginning at `StartTime` and continuing `Duration` seconds,
  *   returns an array of time points, consisting of rounding down to half an hour of points from this interval.
  *  For example, timeSlots(toDateTime('2012-01-01 12:20:00'), 600) = [toDateTime('2012-01-01 12:00:00'), toDateTime('2012-01-01 12:30:00')].
  *  This is necessary to search for hits that are part of the corresponding visit.
  */


#define TIME_SLOT_SIZE 1800

/** Extra transformations.
  * Represents two functions - from datetime (UInt32) and from date (UInt16).
  *
  * Also, the "factor transformation" F is defined for the T transformation.
  * This is a transformation of F such that its value identifies the region of monotonicity T
  *  (for a fixed value of F, the transformation T is monotonic).
  *
  * Or, figuratively, if T is similar to taking the remainder of division, then F is similar to division.
  *
  * Example: to convert T "get the day number in the month" (2015-02-03 -> 3),
  *  factor-transformation F is "round to the nearest month" (2015-02-03 -> 2015-02-01).
  */

/// This factor transformation will say that the function is monotone everywhere.
struct ZeroTransform
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone) { return 0; }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone) { return 0; }
};

struct ToDateImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return UInt16(time_zone.toDayNum(t));
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return d;
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfDayImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toDate(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return d;
    }

    using FactorTransform = ZeroTransform;
};

struct ToMondayImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfWeek(time_zone.toDayNum(t));
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfWeek(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfMonthImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfMonth(time_zone.toDayNum(t));
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfMonth(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfQuarterImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfQuarter(time_zone.toDayNum(t));
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfQuarter(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfYearImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfYear(time_zone.toDayNum(t));
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toFirstDayNumOfYear(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};


struct ToTimeImpl
{
    /// When transforming to time, the date will be equated to 1970-01-02.
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toTime(t) + 86400;
    }

    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toTime", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ToDateImpl;
};

struct ToStartOfMinuteImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toStartOfMinuteInaccurate(t);
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toStartOfMinute", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfFiveMinuteImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toStartOfFiveMinuteInaccurate(t);
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toStartOfFiveMinute", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};

struct ToStartOfHourImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toStartOfHourInaccurate(t);
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toStartOfHour", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};

struct ToYearImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toYear(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toYear(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToMonthImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toMonth(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toMonth(DayNum_t(d));
    }

    using FactorTransform = ToStartOfYearImpl;
};

struct ToDayOfMonthImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toDayOfMonth(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toDayOfMonth(DayNum_t(d));
    }

    using FactorTransform = ToStartOfMonthImpl;
};

struct ToDayOfWeekImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toDayOfWeek(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toDayOfWeek(DayNum_t(d));
    }

    using FactorTransform = ToMondayImpl;
};

struct ToHourImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toHour(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toHour", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ToDateImpl;
};

struct ToMinuteImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toMinuteInaccurate(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toMinute", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ToStartOfHourImpl;
};

struct ToSecondImpl
{
    static inline UInt8 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toSecondInaccurate(t);
    }
    static inline UInt8 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toSecond", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ToStartOfMinuteImpl;
};

struct ToRelativeYearNumImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toYear(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toYear(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToRelativeMonthNumImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeMonthNum(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeMonthNum(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToRelativeWeekNumImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeWeekNum(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeWeekNum(DayNum_t(d));
    }

    using FactorTransform = ZeroTransform;
};

struct ToRelativeDayNumImpl
{
    static inline UInt16 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toDayNum(t);
    }
    static inline UInt16 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        return static_cast<DayNum_t>(d);
    }

    using FactorTransform = ZeroTransform;
};


struct ToRelativeHourNumImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeHourNum(t);
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toRelativeHourNum", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};

struct ToRelativeMinuteNumImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return time_zone.toRelativeMinuteNum(t);
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toRelativeMinuteNum", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};

struct ToRelativeSecondNumImpl
{
    static inline UInt32 execute(UInt32 t, const DateLUTImpl & time_zone)
    {
        return t;
    }
    static inline UInt32 execute(UInt16 d, const DateLUTImpl & time_zone)
    {
        throw Exception("Illegal type Date of argument for function toRelativeSecondNum", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }

    using FactorTransform = ZeroTransform;
};


template<typename FromType, typename ToType, typename Transform>
struct Transformer
{
    static void vector(const PaddedPODArray<FromType> & vec_from, PaddedPODArray<ToType> & vec_to, const DateLUTImpl & time_zone)
    {
        size_t size = vec_from.size();
        vec_to.resize(size);

        for (size_t i = 0; i < size; ++i)
            vec_to[i] = Transform::execute(vec_from[i], time_zone);
    }

    static void constant(const FromType & from, ToType & to, const DateLUTImpl & time_zone)
    {
        to = Transform::execute(from, time_zone);
    }
};


template <typename FromType, typename ToType, typename Transform, typename Name>
struct DateTimeTransformImpl
{
    static void execute(Block & block, const ColumnNumbers & arguments, size_t result)
    {
        using Op = Transformer<FromType, ToType, Transform>;

        const ColumnPtr source_col = block.safeGetByPosition(arguments[0]).column;
        const auto * sources = typeid_cast<const ColumnVector<FromType> *>(source_col.get());
        const auto * const_source = typeid_cast<const ColumnConst<FromType> *>(source_col.get());

        const ColumnConstString * time_zone_column = nullptr;

        if (arguments.size() == 2)
        {
            time_zone_column = typeid_cast<const ColumnConstString *>(block.safeGetByPosition(arguments[1]).column.get());

            if (!time_zone_column)
                throw Exception("Illegal column " + block.safeGetByPosition(arguments[1]).column->getName()
                    + " of second (time zone) argument of function " + Name::name + ", must be constant string",
                    ErrorCodes::ILLEGAL_COLUMN);
        }

        const DateLUTImpl & time_zone = time_zone_column
            ? DateLUT::instance(time_zone_column->getData())
            : DateLUT::instance();

        if (sources)
        {
            auto col_to = std::make_shared<ColumnVector<ToType>>();
            block.safeGetByPosition(result).column = col_to;
            Op::vector(sources->getData(), col_to->getData(), time_zone);
        }
        else if (const_source)
        {
            ToType res;
            Op::constant(const_source->getData(), res, time_zone);
            block.safeGetByPosition(result).column = std::make_shared<ColumnConst<ToType>>(const_source->size(), res);
        }
        else
        {
            throw Exception("Illegal column " + block.safeGetByPosition(arguments[0]).column->getName()
                + " of first argument of function " + Name::name,
                ErrorCodes::ILLEGAL_COLUMN);
        }
    }
};


template <typename ToDataType, typename Transform, typename Name>
class FunctionDateOrDateTimeToSomething : public IFunction
{
public:
    static constexpr auto name = Name::name;
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionDateOrDateTimeToSomething>(); };

    String getName() const override
    {
        return name;
    }

    bool isVariadic() const override { return true; }
    size_t getNumberOfArguments() const override { return 0; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        if (arguments.size() == 1)
        {
            if (!typeid_cast<const DataTypeDate *>(arguments[0].get())
                && !typeid_cast<const DataTypeDateTime *>(arguments[0].get()))
                throw Exception{
                    "Illegal type " + arguments[0]->getName() + " of argument of function " + getName() +
                    ". Should be a date or a date with time", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
        }
        else if (arguments.size() == 2)
        {
            if (!typeid_cast<const DataTypeDateTime *>(arguments[0].get())
                || !typeid_cast<const DataTypeString *>(arguments[1].get()))
                throw Exception{
                    "Function " + getName() + " supports 1 or 2 arguments. The 1st argument "
                    "must be of type Date or DateTime. The 2nd argument (optional) must be "
                    "a constant string with timezone name. The timezone argument is allowed "
                    "only when the 1st argument has the type DateTime",
                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
        }
        else
            throw Exception("Number of arguments for function " + getName() + " doesn't match: passed "
                + toString(arguments.size()) + ", should be 1 or 2",
                ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);

        return std::make_shared<ToDataType>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        IDataType * from_type = block.safeGetByPosition(arguments[0]).type.get();

        if (typeid_cast<const DataTypeDate *>(from_type))
            DateTimeTransformImpl<DataTypeDate::FieldType, typename ToDataType::FieldType, Transform, Name>::execute(block, arguments, result);
        else if (typeid_cast<const DataTypeDateTime * >(from_type))
            DateTimeTransformImpl<DataTypeDateTime::FieldType, typename ToDataType::FieldType, Transform, Name>::execute(block, arguments, result);
        else
            throw Exception("Illegal type " + block.safeGetByPosition(arguments[0]).type->getName() + " of argument of function " + getName(),
                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }


    bool hasInformationAboutMonotonicity() const override
    {
        return true;
    }

    Monotonicity getMonotonicityForRange(const IDataType & type, const Field & left, const Field & right) const override
    {
        IFunction::Monotonicity is_monotonic { true };
        IFunction::Monotonicity is_not_monotonic;

        if (std::is_same<typename Transform::FactorTransform, ZeroTransform>::value)
        {
            is_monotonic.is_always_monotonic = true;
            return is_monotonic;
        }

        /// This method is called only if the function has one argument. Therefore, we do not care about the non-local time zone.
        const DateLUTImpl & date_lut = DateLUT::instance();

        if (left.isNull() || right.isNull())
            return is_not_monotonic;

        /// The function is monotonous on the [left, right] segment, if the factor transformation returns the same values for them.

        if (typeid_cast<const DataTypeDate *>(&type))
        {
            return Transform::FactorTransform::execute(UInt16(left.get<UInt64>()), date_lut)
                == Transform::FactorTransform::execute(UInt16(right.get<UInt64>()), date_lut)
                ? is_monotonic : is_not_monotonic;
        }
        else
        {
            return Transform::FactorTransform::execute(UInt32(left.get<UInt64>()), date_lut)
                == Transform::FactorTransform::execute(UInt32(right.get<UInt64>()), date_lut)
                ? is_monotonic : is_not_monotonic;
        }
    }
};


/// Get the current time. (It is a constant, it is evaluated once for the entire query.)
class FunctionNow : public IFunction
{
public:
    static constexpr auto name = "now";
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionNow>(); };

    String getName() const override
    {
        return name;
    }

    size_t getNumberOfArguments() const override { return 0; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        return std::make_shared<DataTypeDateTime>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        block.safeGetByPosition(result).column = std::make_shared<ColumnConstUInt32>(
            block.rows(),
            time(0));
    }
};


class FunctionToday : public IFunction
{
public:
    static constexpr auto name = "today";
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionToday>(); };

    String getName() const override
    {
        return name;
    }

    size_t getNumberOfArguments() const override { return 0; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        return std::make_shared<DataTypeDate>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        block.safeGetByPosition(result).column = std::make_shared<ColumnConstUInt16>(
            block.rows(),
            DateLUT::instance().toDayNum(time(0)));
    }
};


class FunctionYesterday : public IFunction
{
public:
    static constexpr auto name = "yesterday";
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionYesterday>(); };

    String getName() const override
    {
        return name;
    }

    size_t getNumberOfArguments() const override { return 0; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        return std::make_shared<DataTypeDate>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        block.safeGetByPosition(result).column = std::make_shared<ColumnConstUInt16>(
            block.rows(),
            DateLUT::instance().toDayNum(time(0)) - 1);
    }
};


class FunctionTimeSlot : public IFunction
{
public:
    static constexpr auto name = "timeSlot";
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionTimeSlot>(); };

    String getName() const override
    {
        return name;
    }

    size_t getNumberOfArguments() const override { return 1; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        if (!typeid_cast<const DataTypeDateTime *>(arguments[0].get()))
            throw Exception("Illegal type " + arguments[0]->getName() + " of first argument of function " + getName() + ". Must be DateTime.",
                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

        return std::make_shared<DataTypeDateTime>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        if (const ColumnUInt32 * times = typeid_cast<const ColumnUInt32 *>(block.safeGetByPosition(arguments[0]).column.get()))
        {
            auto res = std::make_shared<ColumnUInt32>();
            ColumnPtr res_holder = res;
            ColumnUInt32::Container_t & res_vec = res->getData();
            const ColumnUInt32::Container_t & vec = times->getData();

            size_t size = vec.size();
            res_vec.resize(size);

            for (size_t i = 0; i < size; ++i)
                res_vec[i] = vec[i] / TIME_SLOT_SIZE * TIME_SLOT_SIZE;

            block.safeGetByPosition(result).column = res_holder;
        }
        else if (const ColumnConstUInt32 * const_times = typeid_cast<const ColumnConstUInt32 *>(block.safeGetByPosition(arguments[0]).column.get()))
        {
            block.safeGetByPosition(result).column = std::make_shared<ColumnConstUInt32>(block.rows(), const_times->getData() / TIME_SLOT_SIZE * TIME_SLOT_SIZE);
        }
        else
            throw Exception("Illegal column " + block.safeGetByPosition(arguments[0]).column->getName()
                    + " of argument of function " + getName(),
                ErrorCodes::ILLEGAL_COLUMN);
    }
};


template <typename DurationType>
struct TimeSlotsImpl
{
    static void vector_vector(
        const PaddedPODArray<UInt32> & starts, const PaddedPODArray<DurationType> & durations,
        PaddedPODArray<UInt32> & result_values, ColumnArray::Offsets_t & result_offsets)
    {
        size_t size = starts.size();

        result_offsets.resize(size);
        result_values.reserve(size);

        ColumnArray::Offset_t current_offset = 0;
        for (size_t i = 0; i < size; ++i)
        {
            for (UInt32 value = starts[i] / TIME_SLOT_SIZE; value <= (starts[i] + durations[i]) / TIME_SLOT_SIZE; ++value)
            {
                result_values.push_back(value * TIME_SLOT_SIZE);
                ++current_offset;
            }

            result_offsets[i] = current_offset;
        }
    }

    static void vector_constant(
        const PaddedPODArray<UInt32> & starts, DurationType duration,
        PaddedPODArray<UInt32> & result_values, ColumnArray::Offsets_t & result_offsets)
    {
        size_t size = starts.size();

        result_offsets.resize(size);
        result_values.reserve(size);

        ColumnArray::Offset_t current_offset = 0;
        for (size_t i = 0; i < size; ++i)
        {
            for (UInt32 value = starts[i] / TIME_SLOT_SIZE; value <= (starts[i] + duration) / TIME_SLOT_SIZE; ++value)
            {
                result_values.push_back(value * TIME_SLOT_SIZE);
                ++current_offset;
            }

            result_offsets[i] = current_offset;
        }
    }

    static void constant_vector(
        UInt32 start, const PaddedPODArray<DurationType> & durations,
        PaddedPODArray<UInt32> & result_values, ColumnArray::Offsets_t & result_offsets)
    {
        size_t size = durations.size();

        result_offsets.resize(size);
        result_values.reserve(size);

        ColumnArray::Offset_t current_offset = 0;
        for (size_t i = 0; i < size; ++i)
        {
            for (UInt32 value = start / TIME_SLOT_SIZE; value <= (start + durations[i]) / TIME_SLOT_SIZE; ++value)
            {
                result_values.push_back(value * TIME_SLOT_SIZE);
                ++current_offset;
            }

            result_offsets[i] = current_offset;
        }
    }

    static void constant_constant(
        UInt32 start, DurationType duration,
        Array & result)
    {
        for (UInt32 value = start / TIME_SLOT_SIZE; value <= (start + duration) / TIME_SLOT_SIZE; ++value)
            result.push_back(static_cast<UInt64>(value * TIME_SLOT_SIZE));
    }
};


class FunctionTimeSlots : public IFunction
{
public:
    static constexpr auto name = "timeSlots";
    static FunctionPtr create(const Context & context) { return std::make_shared<FunctionTimeSlots>(); };

    String getName() const override
    {
        return name;
    }

    size_t getNumberOfArguments() const override { return 2; }

    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        if (!typeid_cast<const DataTypeDateTime *>(arguments[0].get()))
            throw Exception("Illegal type " + arguments[0]->getName() + " of first argument of function " + getName() + ". Must be DateTime.",
                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

        if (!typeid_cast<const DataTypeUInt32 *>(arguments[1].get()))
            throw Exception("Illegal type " + arguments[1]->getName() + " of second argument of function " + getName() + ". Must be UInt32.",
                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

        return std::make_shared<DataTypeArray>(std::make_shared<DataTypeDateTime>());
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result) override
    {
        const ColumnUInt32 * starts = typeid_cast<const ColumnUInt32 *>(block.safeGetByPosition(arguments[0]).column.get());
        const ColumnConstUInt32 * const_starts = typeid_cast<const ColumnConstUInt32 *>(block.safeGetByPosition(arguments[0]).column.get());

        const ColumnUInt32 * durations = typeid_cast<const ColumnUInt32 *>(block.safeGetByPosition(arguments[1]).column.get());
        const ColumnConstUInt32 * const_durations = typeid_cast<const ColumnConstUInt32 *>(block.safeGetByPosition(arguments[1]).column.get());

        auto res = std::make_shared<ColumnArray>(std::make_shared<ColumnUInt32>());
        ColumnPtr res_holder = res;
        ColumnUInt32::Container_t & res_values = typeid_cast<ColumnUInt32 &>(res->getData()).getData();

        if (starts && durations)
        {
            TimeSlotsImpl<UInt32>::vector_vector(starts->getData(), durations->getData(), res_values, res->getOffsets());
            block.safeGetByPosition(result).column = res_holder;
        }
        else if (starts && const_durations)
        {
            TimeSlotsImpl<UInt32>::vector_constant(starts->getData(), const_durations->getData(), res_values, res->getOffsets());
            block.safeGetByPosition(result).column = res_holder;
        }
        else if (const_starts && durations)
        {
            TimeSlotsImpl<UInt32>::constant_vector(const_starts->getData(), durations->getData(), res_values, res->getOffsets());
            block.safeGetByPosition(result).column = res_holder;
        }
        else if (const_starts && const_durations)
        {
            Array const_res;
            TimeSlotsImpl<UInt32>::constant_constant(const_starts->getData(), const_durations->getData(), const_res);
            block.safeGetByPosition(result).column = std::make_shared<ColumnConstArray>(block.rows(), const_res, std::make_shared<DataTypeArray>(std::make_shared<DataTypeDateTime>()));
        }
        else
            throw Exception("Illegal columns " + block.safeGetByPosition(arguments[0]).column->getName()
                    + ", " + block.safeGetByPosition(arguments[1]).column->getName()
                    + " of arguments of function " + getName(),
                ErrorCodes::ILLEGAL_COLUMN);
    }
};


struct NameToYear                 { static constexpr auto name = "toYear"; };
struct NameToMonth                 { static constexpr auto name = "toMonth"; };
struct NameToDayOfMonth            { static constexpr auto name = "toDayOfMonth"; };
struct NameToDayOfWeek            { static constexpr auto name = "toDayOfWeek"; };
struct NameToHour                 { static constexpr auto name = "toHour"; };
struct NameToMinute                { static constexpr auto name = "toMinute"; };
struct NameToSecond                { static constexpr auto name = "toSecond"; };
struct NameToStartOfDay            { static constexpr auto name = "toStartOfDay"; };
struct NameToMonday                { static constexpr auto name = "toMonday"; };
struct NameToStartOfMonth        { static constexpr auto name = "toStartOfMonth"; };
struct NameToStartOfQuarter        { static constexpr auto name = "toStartOfQuarter"; };
struct NameToStartOfYear        { static constexpr auto name = "toStartOfYear"; };
struct NameToStartOfMinute        { static constexpr auto name = "toStartOfMinute"; };
struct NameToStartOfFiveMinute    { static constexpr auto name = "toStartOfFiveMinute"; };
struct NameToStartOfHour        { static constexpr auto name = "toStartOfHour"; };
struct NameToTime                 { static constexpr auto name = "toTime"; };
struct NameToRelativeYearNum    { static constexpr auto name = "toRelativeYearNum"; };
struct NameToRelativeMonthNum    { static constexpr auto name = "toRelativeMonthNum"; };
struct NameToRelativeWeekNum    { static constexpr auto name = "toRelativeWeekNum"; };
struct NameToRelativeDayNum        { static constexpr auto name = "toRelativeDayNum"; };
struct NameToRelativeHourNum    { static constexpr auto name = "toRelativeHourNum"; };
struct NameToRelativeMinuteNum    { static constexpr auto name = "toRelativeMinuteNum"; };
struct NameToRelativeSecondNum    { static constexpr auto name = "toRelativeSecondNum"; };


using FunctionToYear = FunctionDateOrDateTimeToSomething<DataTypeUInt16,    ToYearImpl,         NameToYear>     ;
using FunctionToMonth = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToMonthImpl,         NameToMonth>     ;
using FunctionToDayOfMonth = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToDayOfMonthImpl,     NameToDayOfMonth> ;
using FunctionToDayOfWeek = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToDayOfWeekImpl,     NameToDayOfWeek> ;
using FunctionToHour = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToHourImpl,         NameToHour>     ;
using FunctionToMinute = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToMinuteImpl,         NameToMinute>     ;
using FunctionToSecond = FunctionDateOrDateTimeToSomething<DataTypeUInt8,    ToSecondImpl,         NameToSecond>     ;
using FunctionToStartOfDay = FunctionDateOrDateTimeToSomething<DataTypeDateTime,    ToStartOfDayImpl, NameToStartOfDay>;
using FunctionToMonday = FunctionDateOrDateTimeToSomething<DataTypeDate,        ToMondayImpl,         NameToMonday>     ;
using FunctionToStartOfMonth = FunctionDateOrDateTimeToSomething<DataTypeDate,        ToStartOfMonthImpl, NameToStartOfMonth>;
using FunctionToStartOfQuarter = FunctionDateOrDateTimeToSomething<DataTypeDate,    ToStartOfQuarterImpl,     NameToStartOfQuarter> ;
using FunctionToStartOfYear = FunctionDateOrDateTimeToSomething<DataTypeDate,        ToStartOfYearImpl,     NameToStartOfYear> ;
using FunctionToStartOfMinute = FunctionDateOrDateTimeToSomething<DataTypeDateTime,    ToStartOfMinuteImpl, NameToStartOfMinute>;
using FunctionToStartOfFiveMinute = FunctionDateOrDateTimeToSomething<DataTypeDateTime,    ToStartOfFiveMinuteImpl, NameToStartOfFiveMinute>;
using FunctionToStartOfHour = FunctionDateOrDateTimeToSomething<DataTypeDateTime,    ToStartOfHourImpl,     NameToStartOfHour> ;
using FunctionToTime = FunctionDateOrDateTimeToSomething<DataTypeDateTime,    ToTimeImpl,         NameToTime>     ;

using FunctionToRelativeYearNum = FunctionDateOrDateTimeToSomething<DataTypeUInt16,    ToRelativeYearNumImpl,         NameToRelativeYearNum>     ;
using FunctionToRelativeMonthNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeMonthNumImpl,     NameToRelativeMonthNum> ;
using FunctionToRelativeWeekNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeWeekNumImpl,         NameToRelativeWeekNum>     ;
using FunctionToRelativeDayNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeDayNumImpl,         NameToRelativeDayNum>     ;

using FunctionToRelativeHourNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeHourNumImpl,         NameToRelativeHourNum>     ;
using FunctionToRelativeMinuteNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeMinuteNumImpl,     NameToRelativeMinuteNum> ;
using FunctionToRelativeSecondNum = FunctionDateOrDateTimeToSomething<DataTypeUInt32,    ToRelativeSecondNumImpl,     NameToRelativeSecondNum> ;


}