// Copyright (C) 2015-2019 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef KEA_BOOST_TIME_UTILS_H
#define KEA_BOOST_TIME_UTILS_H

#include <boost/date_time/posix_time/posix_time.hpp>
#include <string>

namespace isc {
namespace util {

/// @brief The number of digits of fractional seconds supplied by the
/// underlying class, boost::posix_time.  Typically 6 = microseconds.
const size_t MAX_FSECS_PRECISION=boost::posix_time::time_duration::num_fractional_digits();

/// @brief Converts ptime structure to text
///
/// This is Kea implementation for converting ptime to strings.
/// It's a functional equivalent of boost::posix_time::to_simple_string. We do
/// not use it, though, because it would introduce unclear dependency on
/// boost_time_date library. First, we try to avoid depending on boost libraries
/// (we tend to use only the headers). Second, this dependency is system
/// specific, i.e. it is required on Ubuntu and FreeBSD, but doesn't seem to
/// be needed on OS X. Since the functionality needed is minor, we decided to
/// reimplement it on our own, rather than introduce extra dependencies.
/// This explanation also applies to @ref durationToText.
/// @param t ptime value to convert to text
/// @param fsecs_precision number of digits of precision for fractional seconds.
/// Default is given by boost::posix_time::time_duration::num_fractional_digits().
/// Zero omits the value.
///
/// @return a string representing time
std::string ptimeToText(boost::posix_time::ptime t,
                        size_t fsecs_precision = MAX_FSECS_PRECISION);

/// @brief Converts StatsDuration to text
///
/// This is Kea equivalent of boost::posix_time::to_simple_string(time_duration).
/// See @ref ptimeToText for explanation why we chose our own implementation.
/// @param dur duration value to convert to text
/// @param fsecs_precision number of digits of precision for fractional seconds.
/// Default is given by boost::posix_time::time_duration::num_fractional_digits().
/// Zero omits the value.
///
/// @return a string representing time
std::string durationToText(boost::posix_time::time_duration dur,
                          size_t fsecs_precision = MAX_FSECS_PRECISION);

}; // end of isc::util namespace
}; // end of isc namespace

#endif