@publidata/utils-opening-hours/src/cached-opening-hours.js

Collection of methods to handle opening hours

const OpeningHours = require("opening_hours");
const dayjs = require("dayjs");
const nominatimModule = require("./nominatim");

const cache = new Map();

function nominatimCacheKey(n) {
  if (!n) return "default";
  try {
    return JSON.stringify(n);
  } catch {
    return "default";
  }
}

/**
 * Cached opening_hours.js instances keyed by (OH string + nominatim).
 *
 * @param {string} ohString
 * @param {object} [nominatim] defaults to nominatim.get()
 * @returns {object|null}
 */
function getCachedOpeningHours(ohString, nominatim) {
  if (!ohString) return null;
  const nom = nominatim != null ? nominatim : nominatimModule.get();
  const key = `${ohString}\0${nominatimCacheKey(nom)}`;
  if (cache.has(key)) return cache.get(key);
  try {
    const instance = new OpeningHours(ohString, nom);
    cache.set(key, instance);
    return instance;
  } catch {
    return null;
  }
}

/**
 * @param {string} ohString
 * @param {Date} date
 * @param {object} [nominatim]
 * @returns {boolean|null} null if OH string is invalid
 */
function getOpeningStateAt(ohString, date, nominatim) {
  const oh = getCachedOpeningHours(ohString, nominatim);
  if (!oh) return null;
  const d = date instanceof Date ? date : new Date(date);
  return oh.getState(d);
}

/**
 * @param {string} ohString
 * @param {Date} fromDate
 * @param {object} [nominatim]
 * @returns {Date|null}
 */
function getNextOpeningChange(ohString, fromDate, nominatim) {
  const oh = getCachedOpeningHours(ohString, nominatim);
  if (!oh) return null;
  const d = fromDate instanceof Date ? fromDate : new Date(fromDate);
  return oh.getNextChange(d);
}

/**
 * Whether the OH string defines an open interval on that calendar day
 * (opening exception / regular collection day without 24/7 prefix).
 *
 * @param {string} ohString
 * @param {import("dayjs").Dayjs} day
 * @param {object} [nominatim]
 */
function hasOpenIntervalOnDay(ohString, day, nominatim) {
  const oh = getCachedOpeningHours(ohString, nominatim);
  if (!oh) return false;
  const dayStart = day.startOf("day").toDate();
  if (oh.getState(dayStart)) return true;
  const nextChange = oh.getNextChange(new Date(dayStart.valueOf() - 1));
  return (
    nextChange !== null &&
    dayjs(nextChange).isSame(day, "day") &&
    oh.getState(nextChange)
  );
}

module.exports = {
  getCachedOpeningHours,
  getOpeningStateAt,
  getNextOpeningChange,
  hasOpenIntervalOnDay
};