/*
 * @brief Defines and implements functions to handle timestamps
 * @file helper/UtcTime.h
 * @author Sven Czarnian <devel@svcz.de>
 * @copyright Copyright 2020-2021 Sven Czarnian
 * @license This project is published under the GNU General Public License v3 (GPLv3)
 */

#pragma once

#include <ctime>
#include <chrono>
#include <sstream>
#include <string>
#include <iomanip>

namespace aman {
    /**
     * @brief Defines helper functions to handle system timestamps and UTC timestamps
     * @ingroup helper
     */
    class UtcTime {
    public:
        using Point = std::chrono::utc_clock::time_point;

        UtcTime() = delete;
        UtcTime(const UtcTime&) = delete;
        UtcTime(UtcTime&&) = delete;
        UtcTime& operator=(const UtcTime&) = delete;
        UtcTime& operator=(UtcTime&&) = delete;

        /**
         * @brief Returns the current time in UTC
         * @return The current UTC time
         */
        static __inline Point currentUtc() {
            return std::chrono::utc_clock::now();
        }

        /**
         * @brief Converts a string into a std::chrono::system_clock::time_point in UTC
         * @param[in] date The string containing the timepoint
         * @return The converted time
         */
        static __inline Point stringToTime(const std::string& date) {
            Point retval;
            std::stringstream stream(date);
            std::chrono::from_stream(stream, "%Y-%m-%d %X", retval);
            return retval;
        }

        /**
         * @brief Converts a time point into a string
         * The function converts into the following format:
         * - %y%m%d%H%M
         * @param[in] time The timepoint which needs to be converted in UTC
         * @return The converted time
         */
        static __inline std::string timeToString(const Point& time, const std::string& format = "%Y-%m-%d %X") {
            if ((std::chrono::time_point<std::chrono::utc_clock>::max)() != time) {
                std::stringstream stream;
                stream << std::format("{0:" + format + "}", time);
                return stream.str();
            }
            else {
                return "";
            }
        }
    };
}