//
//  Copyright (c) 2009-2011 Artyom Beilis (Tonkikh)
//
//  Distributed under the Boost Software License, Version 1.0. (See
//  accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_LOCALE_DATE_TIME_FACET_HPP_INCLUDED
#define BOOST_LOCALE_DATE_TIME_FACET_HPP_INCLUDED

#include <boost/locale/config.hpp>
#ifdef BOOST_MSVC
#  pragma warning(push)
#  pragma warning(disable : 4275 4251 4231 4660)
#endif

#include <boost/cstdint.hpp>
#include <locale>

namespace boost {
    namespace locale {
        ///
        /// \brief Namespace that contains various types for manipulation with dates
        ///
        namespace period {
            ///
            /// \brief This namespace holds a enum of various period types like era, year, month, etc..
            ///
            namespace marks {
                /// \brief the type that defines a flag that holds a period identifier
                enum period_mark {
                    invalid,                    ///< Special invalid value, should not be used directly
                    era,                        ///< Era i.e. AC, BC in Gregorian and Julian calendar, range [0,1]
                    year,                       ///< Year, it is calendar specific, for example 2011 in Gregorian calendar.
                    extended_year,              ///< Extended year for Gregorian/Julian calendars, where 1 BC == 0, 2 BC == -1.
                    month,                      ///< The month of year, calendar specific, in Gregorian [0..11]
                    day,                        ///< The day of month, calendar specific, in Gregorian [1..31]
                    day_of_year,                ///< The number of day in year, starting from 1, in Gregorian  [1..366]
                    day_of_week,                ///< Day of week, Sunday=1, Monday=2,..., Saturday=7.
                                                ///< Note that that updating this value respects local day of week, so for example,
                                                ///< If first day of week is Monday and the current day is Tuesday then setting
                                                ///< the value to Sunday (1) would forward the date by 5 days forward and not backward
                                                ///< by two days as it could be expected if the numbers were taken as is.
                    day_of_week_in_month,       ///< Original number of the day of the week in month. For example 1st Sunday, 
                                                ///< 2nd Sunday, etc. in Gregorian [1..5]
                    day_of_week_local,          ///< Local day of week, for example in France Monday is 1, in US Sunday is 1, [1..7]
                    hour,                       ///< 24 clock hour [0..23]
                    hour_12,                    ///< 12 clock hour [0..11]
                    am_pm,                      ///< am or pm marker [0..1]
                    minute,                     ///< minute [0..59]
                    second,                     ///< second [0..59]
                    week_of_year,               ///< The week number in the year
                    week_of_month,              ///< The week number within current month
                    first_day_of_week,          ///< First day of week, constant, for example Sunday in US = 1, Monday in France = 2
                };

            } // marks

            ///
            /// \brief This class holds a type that represents certain period of time like
            /// year, hour, second and so on.
            ///
            /// It can be created from either marks::period_mark type or by using shortcuts in period
            /// namespace - calling functions like period::year(), period::hour() and so on.
            ///
            /// Basically it represents the same object as enum marks::period_mark but allows to
            /// provide save operator overloading that would not collide with casing of enum to
            /// numeric values.
            ///
            class period_type {
            public:
                ///
                /// Create a period of specific type, default is invalid.
                ///
                period_type(marks::period_mark m = marks::invalid) : mark_(m) 
                {
                }
               
                ///
                /// Get the value of marks::period_mark it was created with.
                /// 
                marks::period_mark mark() const
                {
                    return mark_;
                }

                ///
                /// Check if two periods are the same
                ///
                bool operator==(period_type const &other) const
                {
                    return mark()==other.mark();
                }
                ///
                /// Check if two periods are different
                ///
                bool operator!=(period_type const &other) const
                {
                    return mark()!=other.mark();
                }
            private:
                marks::period_mark mark_;
            };

        } // namespace period

        ///
        /// Structure that define POSIX time, seconds and milliseconds
        /// since Jan 1, 1970, 00:00 not including leap seconds.
        ///
        struct posix_time {
            int64_t seconds; ///< Seconds since epoch
            uint32_t nanoseconds;  ///< Nanoseconds resolution
        };

        ///
        /// This class defines generic calendar class, it is used by date_time and calendar
        /// objects internally. It is less useful for end users, but it is build for localization
        /// backend implementation
        ///

        class abstract_calendar {
        public:

            ///
            /// Type that defines how to fetch the value
            ///
            typedef enum {
                absolute_minimum,   ///< Absolute possible minimum for the value, for example for day is 1
                actual_minimum,     ///< Actual minimal value for this period.
                greatest_minimum,   ///< Maximal minimum value that can be for this period
                current,            ///< Current value of this period
                least_maximum,      ///< The last maximal value for this period, For example for Gregorian calendar
                                    ///< day it is 28
                actual_maximum,     ///< Actual maximum, for it can be 28, 29, 30, 31 for day according to current month
                absolute_maximum,   ///< Maximal value, for Gregorian day it would be 31.
            } value_type;

            ///
            /// A way to update the value
            ///
            typedef enum {
                move,   ///< Change the value up or down effecting others for example 1990-12-31 + 1 day = 1991-01-01
                roll,   ///< Change the value up or down not effecting others for example 1990-12-31 + 1 day = 1990-12-01
            } update_type;

            ///
            /// Information about calendar
            ///
            typedef enum {
                is_gregorian,   ///< Check if the calendar is Gregorian
                is_dst          ///< Check if the current time is in daylight time savings
            } calendar_option_type;

            ///
            /// Make a polymorphic copy of the calendar
            ///
            virtual abstract_calendar *clone() const = 0;

            ///
            /// Set specific \a value for period \a p, note not all values are settable.
            ///
            /// After call of set_value you may want to call normalize() function to make sure
            /// vall periods are updated, if you set sereral fields that are part of single
            /// date/time representation you should call set_value several times and then
            /// call normalize().
            ///
            /// If normalize() is not called after set_value, the behavior is undefined
            ///
            virtual void set_value(period::marks::period_mark p,int value) = 0;

            ///
            /// Recalculate all periods after setting them, should be called after use of set_value() function.
            ///
            virtual void normalize() = 0;

            ///
            /// Get specific value for period \a p according to a value_type \a v
            ///
            virtual int get_value(period::marks::period_mark p,value_type v) const = 0;

            ///
            /// Set current time point
            ///
            virtual void set_time(posix_time const &p)  = 0;
            ///
            /// Get current time point
            ///
            virtual posix_time get_time() const  = 0;

            ///
            /// Set option for calendar, for future use
            ///
            virtual void set_option(calendar_option_type opt,int v) = 0;
            ///
            /// Get option for calendar, currently only check if it is Gregorian calendar
            ///
            virtual int get_option(calendar_option_type opt) const = 0;

            ///
            /// Adjust period's \a p value by \a difference items using a update_type \a u.
            /// Note: not all values are adjustable
            ///
            virtual void adjust_value(period::marks::period_mark p,update_type u,int difference) = 0;

            ///
            /// Calculate the difference between this calendar  and \a other in \a p units
            ///
            virtual int difference(abstract_calendar const *other,period::marks::period_mark p) const = 0;

            ///
            /// Set time zone, empty - use system
            ///
            virtual void set_timezone(std::string const &tz) = 0;
            ///
            /// Get current time zone, empty - system one
            ///
            virtual std::string get_timezone() const = 0;

            ///
            /// Check of two calendars have same rules
            ///
            virtual bool same(abstract_calendar const *other) const = 0;

            virtual ~abstract_calendar()
            {
            }

        };

        ///
        /// \brief the facet that generates calendar for specific locale
        ///
        class BOOST_LOCALE_DECL calendar_facet : public std::locale::facet {
        public:
            ///
            /// Basic constructor
            ///
            calendar_facet(size_t refs = 0) : std::locale::facet(refs) 
            {
            }
            ///
            /// Create a new calendar that points to current point of time.
            ///
            virtual abstract_calendar *create_calendar() const = 0;

            ///
            /// Locale id (needed to work with std::locale)
            ///
            static std::locale::id id;
        };

    } // locale
} // boost

#ifdef BOOST_MSVC
#pragma warning(pop)
#endif


#endif
// vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4