freeice/index.js

/* jshint node: true */
'use strict';

/**
  # freeice

  The `freeice` module is a simple way of getting random STUN or TURN server
  for your WebRTC application.  The list of servers (just STUN at this stage)
  were sourced from this [gist](https://gist.github.com/zziuni/3741933).

  ## Example Use

  The following demonstrates how you can use `freeice` with
  [rtc-quickconnect](https://github.com/rtc-io/rtc-quickconnect):

  <<< examples/quickconnect.js

  As the `freeice` module generates ice servers in a list compliant with the
  WebRTC spec you will be able to use it with raw `RTCPeerConnection`
  constructors and other WebRTC libraries. 

  ## Hey, don't use my STUN/TURN server!

  If for some reason your free STUN or TURN server ends up in the
  [list](servers.js) of servers that is used in this module, you can feel
  free to open an issue on this repository and those servers will be removed
  within 24 hours (or sooner).  This is the quickest and probably the most
  polite way to have something removed (and provides us some visibility
  if someone opens a pull request requesting that a server is added).

  ## Please add my server!

  If you have a server that you wish to add to the list, that's awesome! I'm
  sure I speak on behalf of a whole pile of WebRTC developers who say thanks.
  To get it into the list, feel free to either open a pull request or if you
  find that process a bit daunting then just create an issue requesting
  the addition of the server (make sure you provide all the details, and if
  you have a Terms of Service then including that in the PR/issue would be
  awesome).

  ## I know of a free server, can I add it?

  Sure, if you do your homework and make sure it is ok to use (I'm currently
  in the process of reviewing the terms of those STUN servers included from
  the original list).  If it's ok to go, then please see the previous entry
  for how to add it.

  ## Current List of Servers

  * current as at the time of last `README.md` file generation

  <<< servers.js

**/

var freeice = module.exports = function(opts) {
  // if a list of servers has been provided, then use it instead of defaults
  var servers = (opts || {}).servers || require('./servers');

  var stunCount = (opts || {}).stun || 1;
  var turnCount = (opts || {}).turn || 0;
  var selected;

  function getServers(type, count) {
    var out = [];
    var input = [].concat(servers[type]);
    var idx;

    while (input.length && out.length < count) {
      idx = (Math.random() * input.length) | 0;
      out = out.concat(input.splice(idx, 1));
    }

    return out.map(function(url) {
      return { url: type + ':' + url };
    });
  }

  // add stun servers
  selected = [].concat(getServers('stun', stunCount));

  if (turnCount) {
    selected = selected.concat(getServers('turn', turnCount));
  }

  return selected;
};