const moment = require('moment-timezone');
const one_minute = 60000; // 1000 * 60
const one_hour = 3600000; // 1000 * 60 * 60
const one_day = 86400000; // 1000 * 60 * 60 * 24
const FORMATTERS = {
    full: "dddd MMM Do hh:mm:ss:SSSS a z",
    short: "hh:mm:ss:SSSS a z",
    iso: "YYYY-MM-DD",
}

function now(time, format) {
    return moment(time, format).tz("America/New_York");
}

let things_to_do_each_day = [];
let today = now().startOf('day');

async function process_daily_queue(wait_ms, delayFunction) {
    today.add(1, 'days');

    return Promise.all([
        function() {
            delayFunction(function() {
                process_daily_queue(one_day, setInterval);
            }, wait_ms);
        },
        ...things_to_do_each_day
    ]);
}

module.exports = {
    now: now,
    today: () => today.clone(),
    format: FORMATTERS,
    // ISO 8601 ride or die
    iso: time => (time || today).format(FORMATTERS.iso),
    days_remaining_until: function(other) {
        return other.diff(today, "days");
    },
    add_to_daily_queue: function(thing_to_do_each_day) {
        things_to_do_each_day.push(thing_to_do_each_day);
    },
    start_daily_interval: function() {
        const start_of_next_day = today.clone().add(1, 'days');
        process_daily_queue(
            (start_of_next_day.diff(now(), "seconds") * 1000) + one_minute,
            setTimeout
        );
    },
    one_minute,
    one_hour,
    one_day
};