text: // @flow
  
  import { toState } from '../base/redux';
  
  const ETHERPAD_OPTIONS = {
      showControls: 'true',
      showChat: 'false',
      showLineNumbers: 'true',
      useMonospaceFont: 'false'
  };
  import { NativeModules } from 'react-native';
  const { AudioMode } = NativeModules;
  
  
  
  /**
   * Retrieves the current sahred document URL.
   *
   * @param {Function|Object} stateful - The redux store or {@code getState} function.
   * @returns {?string} - Current shared document URL or undefined.
   */
  export function getSharedDocumentUrl(stateful: Function | Object) {
  
      
      const state = toState(stateful);
      const { documentUrl } = state['features/etherpad'];
      const { displayName } = state['features/base/settings'];
  
      if (!documentUrl) {
           
          return undefined;
      }
  
      const params = new URLSearchParams(ETHERPAD_OPTIONS);
    
      if (displayName) {
          params.append('userName', displayName);
      }
  
      return `${documentUrl}?${params.toString()}`;
  }
  