// Global game clock constants and date formatting, ported from
// scripts/classes/game_clock.gd. One real second is one in-game hour.

export const SECONDS_PER_HOUR = 1.0;
export const HOURS_PER_DAY = 24;
export const DAYS_PER_YEAR = 365;
export const HOURS_PER_YEAR = HOURS_PER_DAY * DAYS_PER_YEAR;
export const UNIX_SECONDS_PER_HOUR = 3600;
export const START_UNIX_TIME = 946684800;

export const MONTH_NAMES = [
  "January", "February", "March", "April", "May", "June",
  "July", "August", "September", "October", "November", "December",
];

export function unixTime(totalHours) {
  return START_UNIX_TIME + totalHours * UNIX_SECONDS_PER_HOUR;
}

export function dateString(totalHours) {
  const date = new Date(unixTime(totalHours) * 1000);
  const day = date.getUTCDate();
  const month = MONTH_NAMES[date.getUTCMonth()];
  const year = date.getUTCFullYear();
  const hour = date.getUTCHours();
  return `${day} ${month} ${year}, ${String(hour).padStart(2, "0")}:00`;
}

// How many in-game hours there are from `totalHours` to the same moment one
// calendar month later. Months differ in length, so a forecast that speaks of
// "the next month" should not assume a fixed 30 days.
export function hoursInNextMonth(totalHours) {
  const date = new Date(unixTime(totalHours) * 1000);
  const later = new Date(date.getTime());
  later.setUTCMonth(later.getUTCMonth() + 1);
  return Math.round((later.getTime() - date.getTime()) / (UNIX_SECONDS_PER_HOUR * 1000));
}