date-holidays-parser/lib/DateFn.cjs

parser for worldwide holidays

'use strict';

var Parser = require('./Parser.cjs');
var Rule = require('./Rule.cjs');
var PostRule = require('./PostRule.cjs');
var CalEventFactory = require('./CalEventFactory.cjs');

/**
 * handles one rule
 */
class DateFn {
  /**
   * @param {string} rule - unparsed rule
   * @param {array} holidays - all holidays rules (required for bridge day calculations)
   */
  constructor (ruleStr, holidays) {
    const parser = new Parser();
    this.ruleStr = ruleStr;
    this.rules = parser.parse(ruleStr);
    this.ok = !parser.error;
    this.holidays = holidays;
    this.opts = holidays ? holidays[ruleStr] : {};
    this.event = undefined;
    this.cache = new Map();
  }

  /**
   * @param {number} year
   * @returns {this}
   */
  inYear (year) {
    if (this.cache.has(year)) {
      this.event = this.cache.get(year);
      return this
    }

    let ruleFn; // current rule
    const postProc = new PostRule(this.ruleStr, this.opts, this.holidays);

    this.rules.forEach((rule) => {
      if (rule.fn) {
        const calEvent = new CalEventFactory(rule)
          .inYear(year - 1) // run over neighboring dates to catch overlaps
          .inYear(year)
          .inYear(year + 1);
        postProc.push(calEvent);
        ruleFn = new Rule(calEvent);
      } else {
        if (ruleFn.resolve(rule)) {
          postProc.resolve(rule, year);
        }
      }
    });

    const event = postProc.getEvent(year);
    this.cache.set(year, event);

    this.event = event;
    return this
  }

  get (timezone) {
    return this.event.get(timezone)
  }
}

module.exports = DateFn;