@fav/type.to-date/lib/from-rfc3339.js

Convert a string in various date format to a date object.

'use strict';

var isString = require('@fav/type.is-string');
var isValidDate = require('@fav/type.is-valid-date');

var newDate = require('./new-date');

function fromRfc3339(text) {
  if (!isString(text)) {
    return null;
  }

  /* eslint-disable max-len */
  var result = /^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(\.[0-9]+)?(Z|([\+\-])([0-9]{2}):([0-9]{2}))$/.exec(text);
  /* eslint-enable max-len */

  if (!result) {
    return null;
  }

  var year = parseInt(result[1], 10);
  var month = parseInt(result[2], 10);
  var day = parseInt(result[3], 10);
  var hour = parseInt(result[4], 10);
  var minute = parseInt(result[5], 10);
  var second = parseInt(result[6], 10);

  var millis;
  if (result[7]) {
    millis = result[7].slice(1, 4);
    millis += '000'.slice(millis.length);
    millis = parseInt(millis, 10);
  } else {
    millis = 0;
  }

  var zone = result[8];

  if (zone !== 'Z') {
    var zoneSign = (result[9] === '-') ? -1 : 1;
    hour -= parseInt(result[10], 10) * zoneSign;
    minute -= parseInt(result[11], 10) * zoneSign;
  }

  var tz = newDate().getTimezoneOffset();
  var tzMinute = tz % 60;
  var tzHour = (tz - tzMinute) / 60;
  hour -= tzHour;
  minute -= tzMinute;

  var date = newDate(year, month - 1, day, hour, minute, second, millis);
  /* istanbul ignore if */
  if (!isValidDate(date)) {
    return null;
  }
  return date;
}

module.exports = fromRfc3339;