Source: lib/batch_operations.js

var httpSignature = require('http-signature');
var request = require('request');
var errors = require('./errors');
var Promise = require('./promise');

module.exports = {
  addToMany: function(activity, feeds, callback) {
    /**
     * Add one activity to many feeds
     * @method addToMany
     * @memberof StreamClient.prototype
     * @since 2.3.0
     * @param  {object}   activity The activity to add
     * @param  {Array}   feeds    Array of objects describing the feeds to add to
     * @param  {requestCallback} callback Callback called on completion
     * @return {Promise}           Promise object
     */
    return this.makeSignedRequest({
      url: 'feed/add_to_many/',
      body: {
        activity: activity,
        feeds: feeds,
      },
    }, callback);
  },

  followMany: function(follows, activityCopyLimit, callback)  {
    /**
     * Follow multiple feeds with one API call
     * @method followMany
     * @memberof StreamClient.prototype
     * @since 2.3.0
     * @param  {Array}   follows  The follow relations to create
     * @param  {number}  [activityCopyLimit] How many activities should be copied from the target feed
     * @param  {requestCallback} [callback] Callback called on completion
     * @return {Promise}           Promise object
     */
    var qs = {};

    if(activityCopyLimit && typeof activityCopyLimit !== 'number') {
      throw new TypeError('Activity copy limit should be a number');
    }

    if(activityCopyLimit) {
      qs['activity_copy_limit'] = activityCopyLimit;
    }

    return this.makeSignedRequest({
      url: 'follow_many/',
      body: follows,
      qs: qs,
    }, callback);
  },

  makeSignedRequest: function(kwargs, cb) {
    /**
     * Method to create request to api with application level authentication
     * @method makeSignedRequest
     * @memberof StreamClient.prototype
     * @since 2.3.0
     * @access private
     * @param  {object}   kwargs Arguments for the request
     * @param  {requestCallback} cb     Callback to call on completion
     * @return {Promise}         Promise object
     */
    if (!this.apiSecret) {
      throw new errors.SiteError('Missing secret, which is needed to perform signed requests, use var client = stream.connect(key, secret);');
    }

    return new Promise(function(fulfill, reject) {
      this.send('request', 'post', kwargs, cb);

      kwargs.url = this.enrichUrl(kwargs.url);
      kwargs.json = true;
      kwargs.method = 'POST';
      kwargs.headers = { 'X-Api-Key': this.apiKey };

      var callback = this.wrapPromiseTask(cb, fulfill, reject);
      var req = request(kwargs, callback);

      httpSignature.sign(req, {
        algorithm: 'hmac-sha256',
        key: this.apiSecret,
        keyId: this.apiKey,
      });
    }.bind(this));
  },
};