(function() {
  'use strict';

  window.utils = window.utils || {};

  var registeredSetupListeners = {};

/**
 * setup function to initiate a util (utilName) on a scope (sope) with options (options).
 *
 * Utils need to be defined as property of `window.utils` and need to accept a scope and (optionally) options.
 * Example: `window.utils.autoSubmit = function(scope, options) { ... };`
 */

  window.utils.setup = function(utilName, scope, options) {

    var utilInstance;

    if (!utilName || !scope) {
      return;
    }

    options = options || {};

    var listener = function(event) {

      if (event.detail.targetUtil !== utilName) {
        return false;
      }

      if (options.setupFunction) {
        utilInstance = options.setupFunction(scope, options);
      } else {
        var util = window.utils[utilName];
        if (!util) {
          throw new Error('"' + utilName + '" is not a known js util');
        }

        utilInstance = util(scope, options);
      }
    };

    window.utils.teardown(utilName);
    if (registeredSetupListeners[utilName] && !options.singleton) {
      registeredSetupListeners[utilName].push(listener);
    } else {
      registeredSetupListeners[utilName] = [ listener ];
    }

    document.addEventListener('setup', listener);

    document.dispatchEvent(new CustomEvent('setup', {
      detail: { targetUtil: utilName, module: 'none' },
      bubbles: true,
      cancelable: true,
    }));

    return utilInstance;
  };

  window.utils.teardown = function(utilName) {
    if (registeredSetupListeners[utilName]) {
      registeredSetupListeners[utilName].forEach(function(listener) {
        document.removeEventListener('setup', listener);
      });
      delete registeredSetupListeners[utilName];
    }
  }
})();