define(function(require, exports, module) {
'use strict';

var IcalRecurExpansion = require('service/ical_recur_expansion');

function request(file, cb) {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', '/test/unit/' + file + '?' + Date.now(), true);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4) {
      if (xhr.status !== 200) {
        cb(new Error('file not found or other error (' + file + ')', xhr));
      } else {
        cb(null, xhr.responseText);
      }
    }
  };
  xhr.send(null);
}

function camelize(string) {
  var out = string.replace(/(?:^|[-_])(\w)/g, function(_, c) {
    return c ? c.toUpperCase() : '';
  });

  return out[0].toLowerCase() + out.slice(1);
}

const ICAL_ROOT = 'fixtures/caldav/ical/';

var Handlers = {
  /**
   * Load and parse an ical sample
   *
   * @param {String} file location of ical file.
   * @param {Function} node style callback: err, contents.
   */
  ical: function icalLoader(file, callback) {
    request(ICAL_ROOT + file + '.ics', function(err, text) {
      if (err) {
        callback(err);
        return;
      }

      callback(null, text);
    });
  }
};

function Fixtures(type) {
  var pending = 0;
  var self = this;
  var handler = Handlers[type];

  function next() {
    if (!(--pending)) {
      if (self._error) {
        throw self._error;
      }
      self.onready();
    }
  }

  this.load = function loadFixture(file) {
    pending++;
    handler(file, function(err, contents) {
      if (err) {
        self._error = err;
      } else {
        self[camelize(file)] = contents;
      }
      next();
    });
  };

  return this;
}

var Helper = {
  Fixtures: Fixtures,

  _originalExpansionLimit: null,

  resetExpansionLimit: function() {
    if (!Helper._originalExpansionLimit) {
      IcalRecurExpansion.forEachLimit = Helper._originalExpansionLimit;
    }
  },

  setExpansionLimit: function(newLimit) {
    if (!Helper._originalExpansionLimit) {
      Helper._originalExpansionLimit = IcalRecurExpansion.forEachLimit;
    }

    IcalRecurExpansion.forEachLimit = newLimit;
  }
};

module.exports = Helper;

});