function getQuarterMonth(quarter: number) {
  const month = quarter * 3 - 2;
  return month === 10 ? month : `0${month}`;
}

function getPrevousVersion(year: number, quarter: number, nQuarter: number) {
  const versionQuarter = quarter - nQuarter;

  if (versionQuarter <= 0) {
    return `${year - 1}-${getQuarterMonth(versionQuarter + 4)}`;
  }

  return `${year}-${getQuarterMonth(versionQuarter)}`;
}

export function getCurrentApiVersion() {
  const date = new Date();
  const month = date.getUTCMonth();
  const year = date.getUTCFullYear();

  const quarter = Math.floor(month / 3 + 1);

  return {
    year,
    quarter,
    version: `${year}-${getQuarterMonth(quarter)}`,
  };
}

export function getCurrentSupportedApiVersions() {
  const {year, quarter, version: currentVersion} = getCurrentApiVersion();

  const nextVersion =
    quarter === 4
      ? `${year + 1}-01`
      : `${year}-${getQuarterMonth(quarter + 1)}`;

  return [
    getPrevousVersion(year, quarter, 3),
    getPrevousVersion(year, quarter, 2),
    getPrevousVersion(year, quarter, 1),
    currentVersion,
    nextVersion,
    'unstable',
  ];
}