epfl-menu-api/src/index.js

EPFL Menu API

/*
 * (c) William Belle, 2019-2021.
 * See the LICENSE file for more details.
 */

const querystring = require('querystring');
const moment = require('moment');
const got = require('got');

const MENUS_URL = 'https://menus.epfl.ch/cgi-bin/ws-getMenus';
const RESTOS_URL = 'https://menus.epfl.ch/cgi-bin/ws-getRestos';

const DEFAULT_MENUS_OPTIONS = {
  language: 'en',
  partOfDay: 'midi'
};

const TAGS = {
  Volaille: 'Chicken',
  Chinois: 'Chinese',
  Poisson: 'Fish',
  'Fourchette Verte': 'Green Fork',
  Indien: 'Indian',
  Japonais: 'Japanese',
  Libanais: 'Lebanese',
  Viande: 'Meat',
  Pâtes: 'Pasta',
  Pizza: 'Pizza',
  Thaï: 'Thai',
  Végétalien: 'Vegan',
  Végétarien: 'Vegetarian'
};

// Accentuated tags aren't working
const BUGGY_TAGS = {
  Pâtes: 'tes',
  Thaï: 'Tha',
  Végétalien: 'talien',
  Végétarien: 'tarien'
};

const buildMenuUrl = (opts) => {
  const queryParameters = {
    midisoir: opts.partOfDay,
    resto_id: opts.restoId,
    lang: opts.language,
    date: opts.date,
    tags: opts.tags
  };

  return MENUS_URL + '?' + querystring.stringify(queryParameters);
};

const buildRestoUrl = (id) => {
  const queryParameters = {
    resto_id: id
  };

  return RESTOS_URL + '?' + querystring.stringify(queryParameters);
};

const escapeTab = (jsonString) => {
  return jsonString.replace(/\t/g, '\\t');
};

const splitTags = (strTags) => {
  const listTags = strTags.split(',');
  return listTags.map(tag => tag.trim());
};

const findTag = (str) => {
  for (const key of Object.keys(TAGS)) {
    if (str.toLowerCase() === key.toLowerCase() ||
        str.toLowerCase() === TAGS[key].toLowerCase()) {
      return key;
    }
  }
  return null;
};

const fixBuggyTags = (str) => {
  if (str in BUGGY_TAGS) {
    str = BUGGY_TAGS[str];
  }
  return str;
};

const buildValidTags = (listTags) => {
  const validTags = [];
  for (let i = 0; i < listTags.length; i++) {
    const key = findTag(listTags[i]);
    if (key) {
      validTags.push(fixBuggyTags(key));
    } else {
      return null;
    }
  }
  return validTags;
};

const findMenu = (opts = DEFAULT_MENUS_OPTIONS) => {
  opts.language = opts.language || DEFAULT_MENUS_OPTIONS.language;
  opts.partOfDay = opts.partOfDay || DEFAULT_MENUS_OPTIONS.partOfDay;

  if (opts.language !== 'en' && opts.language !== 'fr') {
    return Promise.reject(new TypeError('Language not supported'));
  }

  if (opts.partOfDay !== 'midi' && opts.partOfDay !== 'soir') {
    return Promise.reject(new TypeError('Part of the day not supported'));
  }

  if (opts.date && !moment(opts.date, 'DD/MM/YYYY', true).isValid()) {
    return Promise.reject(new TypeError('Not a valid date'));
  }

  if (opts.tags) {
    let listTags = splitTags(opts.tags);
    listTags = buildValidTags(listTags);
    if (!listTags) {
      return Promise.reject(new TypeError('Not a valid tags'));
    }
    opts.tags = listTags.join(',');
  }

  return getMenu(opts);
};

const getMenu = async function (opts) {
  if (opts.restoId && isNaN(opts.restoId)) {
    return Promise.reject(new TypeError('Not a valid restoId'));
  }
  const resto = await findResto(opts.restoId);
  if (resto.length > 0) {
    const url = buildMenuUrl(opts);
    return promGetMenu(url);
  }
  return Promise.reject(new TypeError('Not a valid restoId'));
};

const promGetMenu = (url) => {
  return new Promise((resolve, reject) => {
    got(url).then((response) => {
      const jsonString = escapeTab(response.body);
      const data = JSON.parse(jsonString);
      resolve(data.menus);
    }).catch((err) => reject(err));
  });
};

const findResto = (id) => {
  const url = buildRestoUrl(id);
  return new Promise((resolve, reject) => {
    got(url).then((response) => {
      const data = JSON.parse(response.body);
      resolve(data.restos);
    }).catch((err) => reject(err));
  });
};

const translateTags = (strTags) => {
  if (!strTags) {
    throw new TypeError('Not a valid tags');
  }

  const listTags = splitTags(strTags);
  const translatedList = [];
  for (let i = 0; i < listTags.length; i++) {
    if (TAGS[listTags[i]]) {
      translatedList.push(TAGS[listTags[i]]);
    } else {
      translatedList.push(listTags[i]);
    }
  }
  return translatedList.join(',');
};

exports.findMenu = findMenu;
exports.findResto = findResto;
exports.translateTags = translateTags;