// Same layout as getFormattedTime() in the RTOS-V2 sketch: "3:07 PM  Wed, 15th October 2026".
// Uses the process timezone, which the Dockerfile sets with ENV TZ.
const DAYS = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];
const MONTHS = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

function getDaySuffix(day) {
    if (day >= 11 && day <= 13) return 'th';
    switch (day % 10) {
        case 1: return 'st';
        case 2: return 'nd';
        case 3: return 'rd';
        default: return 'th';
    }
}

/** Milliseconds since the epoch -> "3:07 PM  Wed, 15th October 2026" ("unknown" if the value is not a valid time) */
export function formatTime(ms) {
    const d = new Date(ms);
    if (Number.isNaN(d.getTime())) return 'unknown';
    const hour24 = d.getHours();
    const hour12 = hour24 % 12 === 0 ? 12 : hour24 % 12;
    const meridiem = hour24 >= 12 ? 'PM' : 'AM';
    const minute = String(d.getMinutes()).padStart(2, '0');
    const day = d.getDate();
    return `${hour12}:${minute} ${meridiem}  ${DAYS[d.getDay()]}, ${day}${getDaySuffix(day)} ${MONTHS[d.getMonth()]} ${d.getFullYear()}`;
}

/** Unix seconds -> same format */
export function formatUnix(seconds) {
    return formatTime(Number(seconds) * 1000);
}