PowerToys/src/common/utils/timeutil.h

#pragma once

#include <ctime>
#include <cinttypes>
#include <string>
#include <optional>
#include <cwctype>

#include <winrt/base.h>

namespace timeutil
{
    inline std::string format_as_local(const char* format_string, const time_t time)
    {
        char timeBuf[256] = {};
        tm localtime{};
        localtime_s(&localtime, &time);
        std::strftime(timeBuf, sizeof(timeBuf), format_string, &localtime);
        return timeBuf;
    }

    inline std::wstring to_string(const time_t time)
    {
        return std::to_wstring(static_cast<uint64_t>(time));
    }

    inline std::optional<std::time_t> from_string(const std::wstring& s)
    {
        try
        {
            if (s.empty())
            {
                return std::nullopt;
            }
            for (wchar_t ch : s)
            {
                if (!iswdigit(ch))
                {
                    return std::nullopt;
                }
            }
            uint64_t i = std::stoull(s);
            return static_cast<std::time_t>(i);
        }
        catch (...)
        {
            return std::nullopt;
        }
    }

    inline std::time_t now()
    {
        return winrt::clock::to_time_t(winrt::clock::now());
    }

    namespace diff
    {
        inline int64_t in_seconds(const std::time_t to, const std::time_t from)
        {
            return static_cast<int64_t>(std::difftime(to, from));
        }

        inline int64_t in_minutes(const std::time_t to, const std::time_t from)
        {
            return static_cast<int64_t>(std::difftime(to, from) / 60);
        }

        inline int64_t in_hours(const std::time_t to, const std::time_t from)
        {
            return static_cast<int64_t>(std::difftime(to, from) / 3600);
        }

        inline int64_t in_days(const std::time_t to, const std::time_t from)
        {
            return static_cast<int64_t>(std::difftime(to, from) / (3600 * 24LL));
        }
    }
}