time_utils.h

#pragma once
#include <ctime>
#include <string>

namespace TimeUtils
{
	/**
	 * @brief
	 * Returns a snapshot of the current time.
	 */
	time_t now() {
		return time_t(0);
	}

	/**
	 * @brief
	 * Calculates the difference between the two specified time points.
	 * 
	 * @param start
	 * The first time point.
	 * 
	 * @param end
	 * The second time point.
	 * 
	 * @returns
	 * The difference between the two time points in seconds.
	 */
	int delta(const time_t& start, const time_t& end) {
		return static_cast<int>(difftime(end, start));
	}

	/**
	 * @brief
	 * Formats the specified time into a string based on the specified format.
	 * 
	 * @param time
	 * The time to format.
	 * 
	 * @param format
	 * The format which will be used to convert the time into a string.
	 */
	std::string format(const time_t& time, const std::string& format) {
		struct tm localTime;
		localtime_s(&localTime, &time);

		size_t result;
		std::string buffer;
		buffer.resize(format.size() + 64);

		size_t result = strftime(buffer.data(), buffer.size(), format.c_str(), &localTime);

		while (result == 0 && !format.empty()) {
			buffer.resize(buffer.size() * 2);
			result = strftime(buffer.data(), buffer.size(), format.c_str(), &localTime);
		}

		buffer.resize(result);
		return buffer;
	}
};