mdal_datetime.hpp

/*
 MDAL - Mesh Data Abstraction Library (MIT License)
 Copyright (C) 2019 Vincent Cloarec (vcloarec at gmail dot com)
*/
 
#ifndef MDAL_DATE_TIME_HPP
#define MDAL_DATE_TIME_HPP
 
#include <string>
#include <vector>
 
#include "mdal.h"
 
namespace MDAL
{
 
  class RelativeTimestamp
  {
    public:
      enum Unit
      {
        milliseconds = 0,
        seconds,
        minutes,
        hours,
        days,
        weeks,
        months_CF,
        exact_years
      };
 
      RelativeTimestamp();
      RelativeTimestamp( double duration, Unit unit );
 
      double value( Unit unit ) const;
 
      bool operator==( const RelativeTimestamp &other ) const;
      bool operator<( const RelativeTimestamp &other ) const;
 
    private:
      RelativeTimestamp( int64_t ms );
      int64_t mDuration = 0; //in ms
 
      friend class DateTime;
  };
 
  class DateTime
  {
    public:
 
      enum Calendar
      {
        Gregorian = 0,
        ProlepticGregorian,
        Julian,
      };
 
      enum Epoch
      {
        Unix = 0,
        JulianDay
      };
 
      DateTime();
      DateTime( int year, int month, int day, int hours = 0, int minutes = 0, double seconds = 0, Calendar calendar = Gregorian );
      DateTime( double value, Epoch epoch );
 
      DateTime( const std::string &fromISO8601 );
 
      std::string toStandardCalendarISO8601() const;
 
      double toJulianDay() const;
 
      std::string toJulianDayString() const;
 
      std::vector<int> expandToCalendarArray() const;
 
      RelativeTimestamp operator-( const DateTime &other ) const;
      DateTime operator+( const RelativeTimestamp &duration ) const;
      DateTime operator-( const RelativeTimestamp &duration ) const;
      bool operator==( const DateTime &other ) const;
      bool operator<( const DateTime &other ) const;
 
      bool isValid() const;
 
    private:
 
      struct DateTimeValues
      {
        int year;
        int month;
        int day;
        int hours;
        int minutes;
        double seconds;
      };
 
      DateTime( int64_t julianTime );
 
      DateTimeValues dateTimeGregorianProleptic() const;
 
      void setWithGregorianCalendarDate( DateTimeValues values );
      void setWithJulianCalendarDate( DateTimeValues values );
      void setWithGregorianJulianCalendarDate( DateTimeValues values );//Uses the adapted formula depending of the date (< or > 1582-10-15)
 
      std::string toString( DateTimeValues values ) const;
 
      int64_t mJulianTime = 0; //Julian day in ms
 
      bool mValid = false;
  };
}
 
#endif // MDAL_DATE_TIME_HPP