#pragma once

#include <ctime>
#include <string>
#include <vector>

namespace radiantwave::datetime {

// Default date format (US convention): MM/DD/YYYY.
constexpr const char* DEFAULT_DATE_FORMAT = "%m/%d/%Y";

// One selectable date format. `name` is a human-friendly convention label;
// `pattern` is the strftime spec used to render it.
struct DateFormatOption {
    std::string name;
    std::string pattern;
};

// The formats offered to the end user, ordered most-to-least common.
std::vector<DateFormatOption> getDateFormatOptions();

// Render `t` in local time using a strftime pattern (e.g. "%m/%d/%Y").
// Falls back to an empty string on error.
std::string formatDate(std::time_t t, const std::string& pattern);

// Render `t` as a 24-hour clock: HH:MM:SS.
std::string formatTime(std::time_t t);

// Convert a 24-hour clock `HH:MM` string to a 12-hour display label, e.g.
// "00:00" -> "12:00 AM", "13:05" -> "1:05 PM". Storage and parsing remain
// 24-hour; this is display-only. Returns `hm24` unchanged when it is not a
// valid 24-hour time.
std::string formatHm12h(const std::string& hm24);

// Render `t` in local time as a 12-hour clock label, e.g. "7:05 PM".
std::string formatTime12h(std::time_t t);

} // namespace radiantwave::datetime