export const SERVER_TIME_ZONE = process.env.NEXT_PUBLIC_SERVER_TIME_ZONE ?? "Europe/Madrid";

export function getDateKeyInTimeZone(date = new Date(), timeZone = SERVER_TIME_ZONE): string {
  const formatter = new Intl.DateTimeFormat("en-CA", {
    timeZone,
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
  });

  const parts = formatter.formatToParts(date);
  const year = parts.find((part) => part.type === "year")?.value;
  const month = parts.find((part) => part.type === "month")?.value;
  const day = parts.find((part) => part.type === "day")?.value;

  if (!year || !month || !day) {
    return date.toISOString().slice(0, 10);
  }

  return `${year}-${month}-${day}`;
}

export function secondsUntilNextPuzzle(now = new Date(), timeZone = SERVER_TIME_ZONE): number {
  const formatter = new Intl.DateTimeFormat("en-GB", {
    timeZone,
    hour12: false,
    hour: "2-digit",
    minute: "2-digit",
    second: "2-digit",
  });
  const parts = formatter.formatToParts(now);
  const hour = Number(parts.find((part) => part.type === "hour")?.value ?? 0) % 24;
  const minute = Number(parts.find((part) => part.type === "minute")?.value ?? 0);
  const second = Number(parts.find((part) => part.type === "second")?.value ?? 0);
  const elapsedToday = hour * 3600 + minute * 60 + second;
  return Math.max(1, 86400 - elapsedToday);
}

export function formatCountdown(totalSeconds: number): string {
  const hours = Math.floor(totalSeconds / 3600);
  const minutes = Math.floor((totalSeconds % 3600) / 60);
  const seconds = totalSeconds % 60;
  return `${hours.toString().padStart(2, "0")}:${minutes.toString().padStart(2, "0")}:${seconds
    .toString()
    .padStart(2, "0")}`;
}

export function formatElapsed(seconds: number): string {
  const minutes = Math.floor(seconds / 60);
  const remainder = seconds % 60;
  return `${minutes}:${remainder.toString().padStart(2, "0")}`;
}