node-nlp/examples/microsoft-bot/node_modules/chrono-node/src/parsers/EN/ENMonthNameMiddleEndianParser.js

Library for NLU (Natural Language Understanding) done in Node.js

/*

    The parser for parsing US's date format that begin with month's name.

    EX.
        - January 13
        - January 13, 2012
        - January 13 - 15, 2012
        - Tuesday, January 13, 2012

    Watch out for:
        - January 12:00
        - January 12.44
        - January 1222344
*/

var moment = require('moment');

var Parser = require('../parser').Parser;
var ParsedResult = require('../../result').ParsedResult;
var util  = require('../../utils/EN');

var PATTERN = new RegExp('(\\W|^)' +
    '(?:' +
        '(?:on\\s*?)?' +
        '(Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sun\\.?|Mon\\.?|Tue\\.?|Wed\\.?|Thu\\.?|Fri\\.?|Sat\\.?)' +
    '\\s*,?\\s*)?' +
    '(Jan\\.?|January|Feb\\.?|February|Mar\\.?|March|Apr\\.?|April|May\\.?|Jun\\.?|June|Jul\\.?|July|Aug\\.?|August|Sep\\.?|Sept\\.?|September|Oct\\.?|October|Nov\\.?|November|Dec\\.?|December)' +
    '(?:-|\/|\\s*,?\\s*)' +
    '(([0-9]{1,2})(?:st|nd|rd|th)?|' + util.ORDINAL_WORDS_PATTERN +')\\s*' +
    '(?:' +
        '(?:to|\\-)\\s*' +
        '(([0-9]{1,2})(?:st|nd|rd|th)?| ' + util.ORDINAL_WORDS_PATTERN + ')\\s*' +
    ')?' +
    '(?:' +
        '(?:-|\/|\\s*,?\\s*)' +
        '(?:([0-9]{4})\\s*(BE|AD|BC)?|([0-9]{1,4})\\s*(AD|BC))\\s*' +
    ')?' +
    '(?=\\W|$)(?!\\:\\d)', 'i');

var WEEKDAY_GROUP = 2;
var MONTH_NAME_GROUP = 3;
var DATE_GROUP = 4;
var DATE_NUM_GROUP = 5;
var DATE_TO_GROUP = 6;
var DATE_TO_NUM_GROUP = 7;
var YEAR_GROUP = 8;
var YEAR_BE_GROUP = 9;
var YEAR_GROUP2 = 10;
var YEAR_BE_GROUP2 = 11;

exports.Parser = function ENMonthNameMiddleEndianParser(){
    Parser.apply(this, arguments);

    this.pattern = function() { return PATTERN; }

    this.extract = function(text, ref, match, opt){

        var result = new ParsedResult({
            text: match[0].substr(match[1].length, match[0].length - match[1].length),
            index: match.index + match[1].length,
            ref: ref,
        });


        var month = match[MONTH_NAME_GROUP];
        month = util.MONTH_OFFSET[month.toLowerCase()];
        var day = match[DATE_NUM_GROUP] ?
            parseInt(match[DATE_NUM_GROUP]) :
            util.ORDINAL_WORDS[match[DATE_GROUP].trim().replace('-', ' ').toLowerCase()];

        var year = null;
        if (match[YEAR_GROUP] || match[YEAR_GROUP2]) {
            year = match[YEAR_GROUP] || match[YEAR_GROUP2];
            year = parseInt(year);

            var yearBE = match[YEAR_BE_GROUP] || match[YEAR_BE_GROUP2];
            if (yearBE) {
                if (/BE/i.test(yearBE)) {
                    // Buddhist Era
                    year = year - 543;
                } else if (/BC/i.test(yearBE)) {
                    // Before Christ
                    year = -year;
                }
            } else if (year < 100){

                year = year + 2000;
            }
        }

        if(year){
            result.start.assign('day', day);
            result.start.assign('month', month);
            result.start.assign('year', year);
        } else {

            //Find the most appropriated year
            var refMoment = moment(ref);
            refMoment.month(month - 1);
            refMoment.date(day);

            var nextYear = refMoment.clone().add(1, 'y');
            var lastYear = refMoment.clone().add(-1, 'y');
            if( Math.abs(nextYear.diff(moment(ref))) < Math.abs(refMoment.diff(moment(ref))) ){
                refMoment = nextYear;
            }
            else if( Math.abs(lastYear.diff(moment(ref))) < Math.abs(refMoment.diff(moment(ref))) ){
                refMoment = lastYear;
            }

            result.start.assign('day', day);
            result.start.assign('month', month);
            result.start.imply('year', refMoment.year());
        }

        // Weekday component
        if (match[WEEKDAY_GROUP]) {
            var weekday = match[WEEKDAY_GROUP];
            weekday = util.WEEKDAY_OFFSET[weekday.toLowerCase()]
            result.start.assign('weekday', weekday);
        }

        // Text can be 'range' value. Such as 'January 12 - 13, 2012'
        if (match[DATE_TO_GROUP]) {
            var endDate = match[DATE_TO_NUM_GROUP] ?
                endDate = parseInt(match[DATE_TO_NUM_GROUP]) :
                util.ORDINAL_WORDS[match[DATE_TO_GROUP].replace('-', ' ').trim().toLowerCase()];

            result.end = result.start.clone();
            result.end.assign('day', endDate);
        }

        result.tags['ENMonthNameMiddleEndianParser'] = true;
        return result;
    }
};