(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global.i18nextXHRBackend = factory());
}(this, (function () { 'use strict';

var arr = [];
var each = arr.forEach;
var slice = arr.slice;

function defaults(obj) {
  each.call(slice.call(arguments, 1), function (source) {
    if (source) {
      for (var prop in source) {
        if (obj[prop] === undefined) obj[prop] = source[prop];
      }
    }
  });
  return obj;
}

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

function addQueryString(url, params) {
  if (params && (typeof params === 'undefined' ? 'undefined' : _typeof(params)) === 'object') {
    var queryString = '',
        e = encodeURIComponent;

    // Must encode data
    for (var paramName in params) {
      queryString += '&' + e(paramName) + '=' + e(params[paramName]);
    }

    if (!queryString) {
      return url;
    }

    url = url + (url.indexOf('?') !== -1 ? '&' : '?') + queryString.slice(1);
  }

  return url;
}

// https://gist.github.com/Xeoncross/7663273
function ajax(url, options, callback, data, cache) {

  if (data && (typeof data === 'undefined' ? 'undefined' : _typeof(data)) === 'object') {
    if (!cache) {
      data['_t'] = new Date();
    }
    // URL encoded form data must be in querystring format
    data = addQueryString('', data).slice(1);
  }

  if (options.queryStringParams) {
    url = addQueryString(url, options.queryStringParams);
  }

  try {
    var x;
    if (XMLHttpRequest) {
      x = new XMLHttpRequest();
    } else {
      x = new ActiveXObject('MSXML2.XMLHTTP.3.0');
    }
    x.open(data ? 'POST' : 'GET', url, 1);
    if (!options.crossDomain) {
      x.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
    }
    x.withCredentials = !!options.withCredentials;
    if (data) {
      x.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
    }
    if (x.overrideMimeType) {
      x.overrideMimeType("application/json");
    }
    var h = options.customHeaders;
    if (h) {
      for (var i in h) {
        x.setRequestHeader(i, h[i]);
      }
    }
    x.onreadystatechange = function () {
      x.readyState > 3 && callback && callback(x.responseText, x);
    };
    x.send(data);
  } catch (e) {
    console && console.log(e);
  }
}

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function getDefaults() {
  return {
    loadPath: '/locales/{{lng}}/{{ns}}.json',
    addPath: '/locales/add/{{lng}}/{{ns}}',
    allowMultiLoading: false,
    parse: JSON.parse,
    crossDomain: false,
    ajax: ajax
  };
}

var Backend = function () {
  function Backend(services) {
    var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

    _classCallCheck(this, Backend);

    this.init(services, options);

    this.type = 'backend';
  }

  _createClass(Backend, [{
    key: 'init',
    value: function init(services) {
      var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

      this.services = services;
      this.options = defaults(options, this.options || {}, getDefaults());
    }
  }, {
    key: 'readMulti',
    value: function readMulti(languages, namespaces, callback) {
      var loadPath = this.options.loadPath;
      if (typeof this.options.loadPath === 'function') {
        loadPath = this.options.loadPath(languages, namespaces);
      }

      var url = this.services.interpolator.interpolate(loadPath, { lng: languages.join('+'), ns: namespaces.join('+') });

      this.loadUrl(url, callback);
    }
  }, {
    key: 'read',
    value: function read(language, namespace, callback) {
      var loadPath = this.options.loadPath;
      if (typeof this.options.loadPath === 'function') {
        loadPath = this.options.loadPath([language], [namespace]);
      }

      var url = this.services.interpolator.interpolate(loadPath, { lng: language, ns: namespace });

      this.loadUrl(url, callback);
    }
  }, {
    key: 'loadUrl',
    value: function loadUrl(url, callback) {
      var _this = this;

      this.options.ajax(url, this.options, function (data, xhr) {
        if (xhr.status >= 500 && xhr.status < 600) return callback('failed loading ' + url, true /* retry */);
        if (xhr.status >= 400 && xhr.status < 500) return callback('failed loading ' + url, false /* no retry */);

        var ret = void 0,
            err = void 0;
        try {
          ret = _this.options.parse(data, url);
        } catch (e) {
          err = 'failed parsing ' + url + ' to json';
        }
        if (err) return callback(err, false);
        callback(null, ret);
      });
    }
  }, {
    key: 'create',
    value: function create(languages, namespace, key, fallbackValue) {
      var _this2 = this;

      if (typeof languages === 'string') languages = [languages];

      var payload = {};
      payload[key] = fallbackValue || '';

      languages.forEach(function (lng) {
        var url = _this2.services.interpolator.interpolate(_this2.options.addPath, { lng: lng, ns: namespace });

        _this2.options.ajax(url, _this2.options, function (data, xhr) {
          //const statusCode = xhr.status.toString();
          // TODO: if statusCode === 4xx do log
        }, payload);
      });
    }
  }]);

  return Backend;
}();

Backend.type = 'backend';

return Backend;

})));