#ifndef DATE_TIME_TIME_HPP___

#define DATE_TIME_TIME_HPP___

/* Copyright (c) 2002,2003,2005 CrystalClear Software, Inc.

 * Use, modification and distribution is subject to the 

 * Boost Software License, Version 1.0. (See accompanying

 * file LICENSE-1.0 or http://www.boost.org/LICENSE-1.0)

 * Author: Jeff Garland, Bart Garst

 * $Date: 2005/04/23 05:39:52 $

 */

/*! @file time.hpp

  This file contains the interface for the time associated classes.

*/

#include "boost/date_time/time_defs.hpp"

#include "boost/operators.hpp"

#include <string>

namespace boost {

namespace date_time {

  //! Representation of a precise moment in time, including the date.

  /*! 

    This class is a skeleton for the interface of a temporal type

    with a resolution that is higher than a day.  It is intended that 

    this class be the base class and that the actual time 

    class be derived using the BN pattern.  In this way, the derived 

    class can make decisions such as 'should there be a default constructor' 

    and what should it set its value to, should there be optional constructors

    say allowing only an time_durations that generate a time from a clock,etc.

    So, in fact multiple time types can be created for a time_system with

    different construction policies, and all of them can perform basic

    operations by only writing a copy constructor.  Finally, compiler 

    errors are also shorter. 

    The real behavior of the time class is provided by the time_system

    template parameter.  This class must provide all the logic

    for addition, subtraction, as well as define all the interface

    types.

  */

  template <class T, class time_system>

  class base_time : private

      boost::less_than_comparable<T

    , boost::equality_comparable<T

      > >

  {

  public:

    typedef T time_type;

    typedef typename time_system::time_rep_type time_rep_type;

    typedef typename time_system::date_type date_type;

    typedef typename time_system::date_duration_type date_duration_type;

    typedef typename time_system::time_duration_type time_duration_type;

    //typedef typename time_system::hms_type hms_type;

    base_time(const date_type& day, 

              const time_duration_type& td, 

              dst_flags dst=not_dst) :

      time_(time_system::get_time_rep(day, td, dst))

    {}

    base_time(special_values sv) :

      time_(time_system::get_time_rep(sv))

    {}

    base_time(const time_rep_type& rhs) :

      time_(rhs)

    {}

    date_type date() const

    {

      return time_system::get_date(time_);

    }

    time_duration_type time_of_day() const

    {

      return time_system::get_time_of_day(time_);

    }

    /*! Optional bool parameter will return time zone as an offset 

     * (ie "+07:00"). Empty string is returned for classes that do 

     * not use a time_zone */

    std::string zone_name(bool as_offset=false) const

    {

      return time_system::zone_name(time_);

    }

    /*! Optional bool parameter will return time zone as an offset 

     * (ie "+07:00"). Empty string is returned for classes that do 

     * not use a time_zone */

    std::string zone_abbrev(bool as_offset=false) const

    {

      return time_system::zone_name(time_);

    }

    //! An empty string is returned for classes that do not use a time_zone

    std::string zone_as_posix_string() const

    {

      return std::string("");

    }

    //! check to see if date is not a value

    bool is_not_a_date_time()  const

    {

      return time_.is_not_a_date_time();

    }

    //! check to see if date is one of the infinity values

    bool is_infinity()  const

    {

      return (is_pos_infinity() || is_neg_infinity()); 

    }

    //! check to see if date is greater than all possible dates

    bool is_pos_infinity()  const

    {

      return time_.is_pos_infinity();

    }

    //! check to see if date is greater than all possible dates

    bool is_neg_infinity()  const

    {

      return time_.is_neg_infinity();

    }

    //! check to see if time is a special value

    bool is_special() const

    {

      return(is_not_a_date_time() || is_infinity());

    }

    //!Equality operator -- others generated by boost::equality_comparable

    bool operator==(const time_type& rhs) const

    {

      return time_system::is_equal(time_,rhs.time_);

    }

    //!Equality operator -- others generated by boost::less_than_comparable

    bool operator<(const time_type& rhs) const

    {

      return time_system::is_less(time_,rhs.time_);

    }

    //! difference between two times

    time_duration_type operator-(const time_type& rhs) const

    {

      return time_system::subtract_times(time_, rhs.time_);

    }

    //! add date durations

    time_type operator+(const date_duration_type& dd) const

    {

      return time_system::add_days(time_, dd);

    }

    time_type operator+=(const date_duration_type& dd)

    {

      time_ = (time_system::get_time_rep(date() + dd, time_of_day()));

      return time_type(time_);

    }

    //! subtract date durations

    time_type operator-(const date_duration_type& dd) const

    {

      return time_system::subtract_days(time_, dd);

    }

    time_type operator-=(const date_duration_type& dd)

    {

      time_ = (time_system::get_time_rep(date() - dd, time_of_day()));

      return time_type(time_);

    }

    //! add time durations

    time_type operator+(const time_duration_type& td) const

    {

      return time_type(time_system::add_time_duration(time_, td));

    }

    time_type operator+=(const time_duration_type& td)

    {

      time_ = (time_system::get_time_rep(date(), time_of_day() + td));

      return time_type(time_);

    }

    //! subtract time durations

    time_type operator-(const time_duration_type& rhs) const

    {

      return time_system::subtract_time_duration(time_, rhs);

    }

    time_type operator-=(const time_duration_type& td) 

    {

      time_ = (time_system::get_time_rep(date(), time_of_day() - td));

      return time_type(time_);

    }

  protected:

    time_rep_type time_;

  };

} } //namespace date_time::boost

#endif