index.js

const Sql = require('sql-extra');
const lunr = require('lunr');
const path = require('path');

var corpus = new Map();
var ranges = new Map();
var index = null;
var ready = false;


function loadCorpus() {
  for(var [k, v] of require('./corpus'))
    corpus.set(k, v);
};

function setupIndex() {
  index = lunr(function() {
    this.ref('group');
    this.field('group');
    this.pipeline.remove(lunr.stopWordFilter);
    for(var r of corpus.values())
      this.add(r);
  });
};

function setupRanges() {
  for(var {group} of corpus.values()) {
    if(!group.includes(' to ')) continue;
    group.replace(/(\d+)\s+to\s+(\d+)/, (m, p1, p2) => {
      ranges.set([parseInt(p1, 10), parseInt(p2, 10)], group);
    });
  }
}

function csv() {
  return path.join(__dirname, 'index.csv');
};

function sql(tab='caloriecoefficient', opt={}) {
  return Sql.setupTable(tab, {group: 'TEXT', cu: 'REAL'}, require('./corpus').values(),
    Object.assign({pk: 'group', index: true, tsvector: {group: 'A'}}, opt));
};

function load() {
  if(ready) return true;
  loadCorpus(); setupIndex(); setupRanges();
  return ready = true;
};

function findEntry(entry) {
  if(!/\d+/.test(entry)) return null;
  var n = parseInt(entry.substring(entry.search(/\d+/)), 10);
  for(var [[bgn, end], group] of ranges)
    if(bgn<=n && n<=end) return group;
  return null;
}

function calorieCoefficient(txt) {
  if(index==null) return [];
  var z = [], txt = txt.replace(/\W|years?|old/gi, ' ');
  var mats = index.search(txt), max = 0;
  for(var mat of mats)
    max = Math.max(max, Object.keys(mat.matchData.metadata).length);
  for(var mat of mats)
    if(Object.keys(mat.matchData.metadata).length===max) z.push(corpus.get(mat.ref));
  var code = findEntry(txt);
  if(!code) return z;
  var mat = corpus.get(code);
  if(z.includes(mat)) z.splice(z.indexOf(mat), 1);
  z.unshift(mat);
  return z;
};
calorieCoefficient.csv = csv;
calorieCoefficient.sql = sql;
calorieCoefficient.load = load;
calorieCoefficient.corpus = corpus;
module.exports = calorieCoefficient;