rrecur-iterator.js

/*jshint -W054 */
(function (exports) {
  'use strict';

  var Rrecur = exports.Rrecur || require('./rrecur').Rrecur
    , RRule
    , moment
    , p
    ;

  function addSubtract(m, rule, method, int) {
    var doubleInt = (rule.interval || 1) * int
      , d = m
      ;

    switch(rule.freq) {
    case 'yearly':
      d[method](doubleInt, 'years');
      break;
    case 'monthly':
      d[method](doubleInt, 'months');
      break;
    case 'weekly':
      d[method](doubleInt, 'weeks');
      break;
    case 'daily':
      d[method](doubleInt, 'days');
      break;
    case 'hourly':
      d[method](doubleInt, 'hours');
      break;
    case 'minutely':
      d[method](doubleInt, 'minutes');
      break;
    case 'secondly':
      d[method](doubleInt, 'seconds');
      break;
    }

    return d.toDate().toISOString();
  }
  function add(m, rule) {
    return addSubtract(m, rule, 'add', 1);
  }

  function subtract(m, rule) {
    return addSubtract(m, rule, 'subtract', 1);
  }

  function getDtStart(m, ruleObj, method) {
    var d = moment(m)
      ;

    return addSubtract(d, ruleObj, method, 2);
  }

  Rrecur.create = Rrecur;
  Rrecur.adustByTzid = function (date, tzid) {
    // TODO convert from tzid to whatever moment understands
    // http://www.twinsun.com/tz/tz-link.htm
    // http://www.unicode.org/cldr/charts/latest/supplemental/zone_tzid.html
    throw new Error("Not Implemented", tzid);
  };
  Rrecur.adustByLocale = function (date, locale) {
    return new Date(date.toString().replace(/GMT.*/, locale));
  };
  Rrecur.adustByOffset = function (date, tzoffset) {
    // this is to keep 10am, but change which offset it is in
    // so that UTC will change to the appropriate zone
    tzoffset = tzoffset || '-0000';
    return new Date(date.toString().replace(/GMT.*/, 'GMT' + tzoffset/* + ' (' + abbr + ')'*/));
    /*
    if ('string' === tzoffset) {
      // convert from "-0430" to "-04:30"
      tzoffset = tzoffset.replace(/\d{2}\d{2}/, "$1:$2");
    }
    */
  };
  p = Rrecur.prototype;
  p.init = function (thing, datestr) {
    var me = this
      ;

    RRule = RRule || exports.RRule || require('rrule').RRule;
    moment = moment || exports.moment || require('moment');

    if (!thing) {
      return;
    }
    me._firstTime = true;
    me._serverLocale = Rrecur.stringifyGmtZone(new Date());
    me._serverOffset = Rrecur.getOffsetFromLocale(me._serverLocale);

    if ('string' === typeof thing) {
      me.__rfcString = thing;
      me.__rruleObj = Rrecur.parse(thing);
    } else {
      me.__rfcString = Rrecur.stringify(thing);
      me.__rruleObj = thing;
    }

    me._rule = {};
    Object.keys(me.__rruleObj).forEach(function (key) {
      if (Array.isArray(me.__rruleObj[key])) {
        me._rule[key] = me.__rruleObj[key].slice(0);
      } else {
        me._rule[key] = me.__rruleObj[key];
      }
    });

    datestr = datestr.toString();
    if (!datestr) {
      if (!me._rule.dtstart) {
        me._rule.dtstart = new Date().toISOString(); // Rrecur.toLocaleISOString(new Date());
        console.error("DTSTART was not specified, falling back to '" + me._rule.dtstart + "'" );
      }
      if (me._rule.tzid) {
        console.error('TZIDs are not yet implemented, falling back to Locale');
        console.warn('TODO use moment timezone');
      }
      if (!me._rule.locale) {
        me._rule.locale = 'GMT-0000 (UTC)'; //new Date().toString();
        console.error("Locale was not specified, falling back to '" + me._rule.locale + "'");
      }
      me._rule.locale = Rrecur.stringifyGmtZone(me._rule.locale);
      me._rule.offset = Rrecur.getOffsetFromLocale(me._rule.locale) 
        ;

      datestr = me._rule.dtstart;
    }

    me._zoneless = datestr
      .toString()                                     // handles Date, Moment, and String
      ;

    if (/GMT/.test(me._zoneless)) {
      me._zoneless = me._zoneless
        .replace(/GMT[+\-]\d{4}.*/, me._serverLocale)   // handles LocaleString
        ;
    } else {
      me._zoneless = me._zoneless
        .replace(/[+\-]\d{4}.*/, 'Z', me._serverOffset) // handles ISOString
        ;
    }

    //console.log('me._zoneless');
    //console.log(me._zoneless);
    me._m = moment(me._zoneless);
    //console.log(me._m.toDate());

    if (me._rule.count) {
      delete me._rule.count;
    }

    // create a string in the timezone of the server
    me._locale = me._rule.locale;
    me._offset = me._rule.offset;
    delete me._rule.locale;
    delete me._rule.offset;

    //console.log(me._rule);
    me._rfcString = Rrecur.stringify(me._rule);
    // Rrule doesn't support TZID or (my own) LOCALE
    console.log(me._rfcString);
    me._rrule = RRule.fromString(me._rfcString);
  };
  p.previous = function () {
    var me = this
      , date
      , odate
      ;

    if (!me._rule.dtstart) {
      me._rule.dtstart = getDtStart(me._m, me._rule, 'subtract');
    }

    //subtract(me._m, me._rule);
    date = me._m.toDate();
    odate = me._m.toDate();
    //console.log('[debug]', date);
    date = me._rrule.before(odate);
    me._m = moment(date);

    if (date && me._firstTime) {
      me._firstTime = false;
    }

    date = me._m.toDate();
    //console.log('prev', date);
    if ('Invalid Date' === date.toString()) {
      me._m = moment(odate);
      return null;
    }

    return Rrecur.toLocaleISOString(date, me._locale);
    /*
    me._m = moment(me._rrule.before(me._m.toDate()));
    return me._m.toDate();
    */
  };
  p.next = function () {
    var me = this
      , date
      , odate
      ;

    /*
    if (!me._rule.until) {
      me._rule.until = getDtStart(me._m, me._rule, 'add');
    }
    */

    /*
    add(me._m, me._rule);
    //return me._rrule.after(me._m.toDate(), true);
    //*/

    date = me._m.toDate();
    odate = me._m.toDate();
    //console.log('after', date);
    me._m = moment(me._rrule.after(date, me._firstTime));

    if (me._firstTime) {
      me._firstTime = false;
    }

    date = me._m.toDate();
    if ('Invalid Date' === date.toString()) {
      me._m = moment(odate);
      return null;
    }

    return Rrecur.toLocaleISOString(date, me._locale);
  };

  exports.Rrecur = Rrecur;
}('undefined' !== typeof exports && exports || new Function('return this')()));