ffrgb / meshviewer

define(['polyglot', 'moment', 'helper'], function (Polyglot, moment, helper) {

  'use strict';

  return function (config) {

    function languageSelect(el) {

      var select = document.createElement('select');

      select.className = 'language-switch';

      select.addEventListener('change', setLocale);

      el.appendChild(select);

      var option = document.createElement('option');

      // Keep english

      option.text = 'Language';

      select.appendChild(option);

      for (var i = 0; i < config.supportedLocale.length; i++) {

        option = document.createElement('option');

        option.text = option.value = config.supportedLocale[i];

        select.appendChild(option);

      }

    }

    function setLocale(event) {

      localStorage.setItem('language', getLocale(event.target.value));

      location.reload();

    }

    function getLocale(input) {

      var language = input || localStorage.getItem('language') || navigator.languages && navigator.languages[0] || navigator.language || navigator.userLanguage;

      var locale = config.supportedLocale[0];

      config.supportedLocale.some(function (item) {

        if (language.indexOf(item) !== -1) {

          locale = item;

          return true;

        }

        return false;

      });

      return locale;

    }

    function setTranslation(json) {

      _.extend(json);

      moment.locale(_.locale(), {

        longDateFormat: {

          LT: 'HH:mm',

          LTS: 'HH:mm:ss',

          L: 'DD.MM.YYYY',

          LL: 'D. MMMM YYYY',

          LLL: 'D. MMMM YYYY HH:mm',

          LLLL: 'dddd, D. MMMM YYYY HH:mm'

        },

        calendar: json.momentjs.calendar,

        relativeTime: json.momentjs.relativeTime

      });

    }

    window._ = new Polyglot({ locale: getLocale(), allowMissing: true });

    helper.getJSON('locale/' + _.locale() + '.json?' + config.cacheBreaker).then(setTranslation);

    return {

      languageSelect: languageSelect

    };

  };

});