text: // @flow
  
  import _ from 'lodash';
  
  import { _CONFIG_STORE_PREFIX } from './constants';
  import parseURLParams from './parseURLParams';
  import logger from './logger';
  
  declare var $: Object;
  
  /**
   * The config keys to whitelist, the keys that can be overridden.
   * Currently we can only whitelist the first part of the properties, like
   * 'p2p.useStunTurn' and 'p2p.enabled' we whitelist all p2p options.
   * The whitelist is used only for config.js.
   *
   * @private
   * @type Array
   */
  const WHITELISTED_KEYS = [
      '_desktopSharingSourceDevice',
      '_peerConnStatusOutOfLastNTimeout',
      '_peerConnStatusRtcMuteTimeout',
      'abTesting',
      'analytics.disabled',
      'autoRecord',
      'autoRecordToken',
      'avgRtpStatsN',
      'callFlowsEnabled',
      'callStatsConfIDNamespace',
      'callStatsID',
      'callStatsSecret',
  
      /**
       * The display name of the CallKit call representing the conference/meeting
       * associated with this config.js including while the call is ongoing in the
       * UI presented by CallKit and in the system-wide call history. The property
       * is meant for use cases in which the room name is not desirable as a
       * display name for CallKit purposes and the desired display name is not
       * provided in the form of a JWT callee. As the value is associated with a
       * conference/meeting, the value makes sense not as a deployment-wide
       * configuration, only as a runtime configuration override/overwrite
       * provided by, for example, Jitsi Meet SDK for iOS.
       *
       * @type string
       */
      'callDisplayName',
  
      /**
       * The handle
       * ({@link https://developer.apple.com/documentation/callkit/cxhandle}) of
       * the CallKit call representing the conference/meeting associated with this
       * config.js. The property is meant for use cases in which the room URL is
       * not desirable as the handle for CallKit purposes. As the value is
       * associated with a conference/meeting, the value makes sense not as a
       * deployment-wide configuration, only as a runtime configuration
       * override/overwrite provided by, for example, Jitsi Meet SDK for iOS.
       *
       * @type string
       */
      'callHandle',
  
      /**
       * The UUID of the CallKit call representing the conference/meeting
       * associated with this config.js. The property is meant for use cases in
       * which Jitsi Meet is to work with a CallKit call created outside of Jitsi
       * Meet and to be adopted by Jitsi Meet such as, for example, an incoming
       * and/or outgoing CallKit call created by Jitsi Meet SDK for iOS
       * clients/consumers prior to giving control to Jitsi Meet. As the value is
       * associated with a conference/meeting, the value makes sense not as a
       * deployment-wide configuration, only as a runtime configuration
       * override/overwrite provided by, for example, Jitsi Meet SDK for iOS.
       *
       * @type string
       */
      'callUUID',
  
      'channelLastN',
      'constraints',
      'debug',
      'debugAudioLevels',
      'defaultLanguage',
      'desktopSharingChromeDisabled',
      'desktopSharingChromeExtId',
      'desktopSharingChromeMinExtVersion',
      'desktopSharingChromeSources',
      'desktopSharingFrameRate',
      'desktopSharingFirefoxDisabled',
      'desktopSharingSources',
      'disable1On1Mode',
      'disableAEC',
      'disableAGC',
      'disableAP',
      'disableAudioLevels',
      'disableDeepLinking',
      'disableH264',
      'disableHPF',
      'disableNS',
      'disableRemoteControl',
      'disableRtx',
      'disableSuspendVideo',
      'displayJids',
      'e2eping',
      'enableDisplayNameInStats',
      'enableLayerSuspension',
      'enableLipSync',
      'disableLocalVideoFlip',
      'enableRemb',
      'enableStatsID',
      'enableTalkWhileMuted',
      'enableTcc',
      'etherpad_base',
      'failICE',
      'fileRecordingsEnabled',
      'firefox_fake_device',
      'forceJVB121Ratio',
      'gatherStats',
      'googleApiApplicationClientID',
      'hiddenDomain',
      'hosts',
      'iAmRecorder',
      'iAmSipGateway',
      'iceTransportPolicy',
      'ignoreStartMuted',
      'liveStreamingEnabled',
      'localRecording',
      'minParticipants',
      'nick',
      'openBridgeChannel',
      'p2p',
      'preferH264',
      'requireDisplayName',
      'resolution',
      'startAudioMuted',
      'startAudioOnly',
      'startBitrate',
      'startSilent',
      'startScreenSharing',
      'startVideoMuted',
      'startWithAudioMuted',
      'startWithVideoMuted',
      'subject',
      'testing',
      'useIPv6',
      'useNicks',
      'useStunTurn',
      'webrtcIceTcpDisable',
      'webrtcIceUdpDisable'
  ];
  
  // XXX The functions getRoomName and parseURLParams are split out of
  // functions.js because they are bundled in both app.bundle and
  // do_external_connect, webpack 1 does not support tree shaking, and we don't
  // want all functions to be bundled in do_external_connect.
  export { default as getRoomName } from './getRoomName';
  export { parseURLParams };
  
  /**
   * Promise wrapper on obtain config method. When HttpConfigFetch will be moved
   * to React app it's better to use load config instead.
   *
   * @param {string} location - URL of the domain from which the config is to be
   * obtained.
   * @param {string} room - Room name.
   * @private
   * @returns {Promise<void>}
   */
  export function obtainConfig(location: string, room: string): Promise<void> {
      return new Promise((resolve, reject) =>
          _obtainConfig(location, room, (success, error) => {
              success ? resolve() : reject(error);
          })
      );
  }
  
  /**
   * Sends HTTP POST request to specified {@code endpoint}. In request the name
   * of the room is included in JSON format:
   * {
   *     "rooomName": "someroom12345"
   * }.
   *
   * @param {string} endpoint - The name of HTTP endpoint to which to send
   * the HTTP POST request.
   * @param {string} roomName - The name of the conference room for which config
   * is requested.
   * @param {Function} complete - The callback to invoke upon success or failure.
   * @returns {void}
   */
  function _obtainConfig(endpoint: string, roomName: string, complete: Function) {
      logger.info(`Send config request to ${endpoint} for room: ${roomName}`);
      $.ajax(
          endpoint,
          {
              contentType: 'application/json',
              data: JSON.stringify({ roomName }),
              dataType: 'json',
              method: 'POST',
  
              error(jqXHR, textStatus, errorThrown) {
                  logger.error('Get config error: ', jqXHR, errorThrown);
                  complete(false, `Get config response status: ${textStatus}`);
              },
              success(data) {
                  const { config, interfaceConfig, loggingConfig } = window;
  
                  try {
                      overrideConfigJSON(
                          config, interfaceConfig, loggingConfig,
                          data);
                      complete(true);
                  } catch (e) {
                      logger.error('Parse config error: ', e);
                      complete(false, e);
                  }
              }
          }
      );
  }
  
  /* eslint-disable max-params, no-shadow */
  
  /**
   * Overrides JSON properties in {@code config} and
   * {@code interfaceConfig} Objects with the values from {@code newConfig}.
   * Overrides only the whitelisted keys.
   *
   * @param {Object} config - The config Object in which we'll be overriding
   * properties.
   * @param {Object} interfaceConfig - The interfaceConfig Object in which we'll
   * be overriding properties.
   * @param {Object} loggingConfig - The loggingConfig Object in which we'll be
   * overriding properties.
   * @param {Object} json - Object containing configuration properties.
   * Destination object is selected based on root property name:
   * {
   *     config: {
   *         // config.js properties here
   *     },
   *     interfaceConfig: {
   *         // interface_config.js properties here
   *     },
   *     loggingConfig: {
   *         // logging_config.js properties here
   *     }
   * }.
   * @returns {void}
   */
  export function overrideConfigJSON(
          config: ?Object, interfaceConfig: ?Object, loggingConfig: ?Object,
          json: Object) {
      for (const configName of Object.keys(json)) {
          let configObj;
  
          if (configName === 'config') {
              configObj = config;
          } else if (configName === 'interfaceConfig') {
              configObj = interfaceConfig;
          } else if (configName === 'loggingConfig') {
              configObj = loggingConfig;
          }
          if (configObj) {
              const configJSON
                  = _getWhitelistedJSON(configName, json[configName]);
  
              if (!_.isEmpty(configJSON)) {
                  logger.info(
                      `Extending ${configName} with: ${
                          JSON.stringify(configJSON)}`);
  
                  // eslint-disable-next-line arrow-body-style
                  _.mergeWith(configObj, configJSON, (oldValue, newValue) => {
  
                      // XXX We don't want to merge the arrays, we want to
                      // overwrite them.
                      return Array.isArray(oldValue) ? newValue : undefined;
                  });
              }
          }
      }
  }
  
  /* eslint-enable max-params, no-shadow */
  
  /**
   * Whitelist only config.js, skips this for others configs
   * (interfaceConfig, loggingConfig).
   * Only extracts overridden values for keys we allow to be overridden.
   *
   * @param {string} configName - The config name, one of config,
   * interfaceConfig, loggingConfig.
   * @param {Object} configJSON - The object with keys and values to override.
   * @private
   * @returns {Object} - The result object only with the keys
   * that are whitelisted.
   */
  function _getWhitelistedJSON(configName, configJSON) {
      if (configName !== 'config') {
          return configJSON;
      }
  
      return _.pick(configJSON, WHITELISTED_KEYS);
  }
  
  /**
   * Restores a Jitsi Meet config.js from {@code localStorage} if it was
   * previously downloaded from a specific {@code baseURL} and stored with
   * {@link storeConfig}.
   *
   * @param {string} baseURL - The base URL from which the config.js was
   * previously downloaded and stored with {@code storeConfig}.
   * @returns {?Object} The Jitsi Meet config.js which was previously downloaded
   * from {@code baseURL} and stored with {@code storeConfig} if it was restored;
   * otherwise, {@code undefined}.
   */
  export function restoreConfig(baseURL: string): ?Object {
      let storage;
      const key = `${_CONFIG_STORE_PREFIX}/${baseURL}`;
  
      try {
          // XXX Even reading the property localStorage of window may throw an
          // error (which is user agent-specific behavior).
          storage = window.localStorage;
  
          const config = storage.getItem(key);
  
          if (config) {
              return JSON.parse(config) || undefined;
          }
      } catch (e) {
          // Somehow incorrect data ended up in the storage. Clean it up.
          storage && storage.removeItem(key);
      }
  
      return undefined;
  }
  
  /* eslint-disable max-params */
  
  /**
   * Inspects the hash part of the location URI and overrides values specified
   * there in the corresponding config objects given as the arguments. The syntax
   * is: {@code https://server.com/room#config.debug=true
   * &interfaceConfig.showButton=false&loggingConfig.something=1}.
   *
   * In the hash part each parameter will be parsed to JSON and then the root
   * object will be matched with the corresponding config object given as the
   * argument to this function.
   *
   * @param {Object} config - This is the general config.
   * @param {Object} interfaceConfig - This is the interface config.
   * @param {Object} loggingConfig - The logging config.
   * @param {URI} location - The new location to which the app is navigating to.
   * @returns {void}
   */
  export function setConfigFromURLParams(
          config: ?Object,
          interfaceConfig: ?Object,
          loggingConfig: ?Object,
          location: Object) {
      const params = parseURLParams(location);
      const json = {};
  
      // At this point we have:
      // params = {
      //     "config.disableAudioLevels": false,
      //     "config.channelLastN": -1,
      //     "interfaceConfig.APP_NAME": "Jitsi Meet"
      // }
      // We want to have:
      // json = {
      //     config: {
      //         "disableAudioLevels": false,
      //         "channelLastN": -1
      //     },
      //     interfaceConfig: {
      //         "APP_NAME": "Jitsi Meet"
      //     }
      // }
      config && (json.config = {});
      interfaceConfig && (json.interfaceConfig = {});
      loggingConfig && (json.loggingConfig = {});
  
      for (const param of Object.keys(params)) {
          let base = json;
          const names = param.split('.');
          const last = names.pop();
  
          for (const name of names) {
              base = base[name] = base[name] || {};
          }
  
          base[last] = params[param];
      }
  
      overrideConfigJSON(config, interfaceConfig, loggingConfig, json);
  }
  
  /* eslint-enable max-params */
  