announce.js

var extend = require('cog/extend');

module.exports = function(signaller) {

  function dataAllowed(data) {
    var cloned = extend({ allow: true }, data);
    signaller('peer:filter', data.id, cloned);

    return cloned.allow;
  }

  return function(args, messageType, srcData, srcState, isDM) {
    var data = args[0];
    var peer;

    // if we have valid data then process
    if (data && data.id && data.id !== signaller.id) {
      if (! dataAllowed(data)) {
        return;
      }
      // check to see if this is a known peer
      peer = signaller.peers.get(data.id);

      // trigger the peer connected event to flag that we know about a
      // peer connection. The peer has passed the "filter" check but may
      // be announced / updated depending on previous connection status
      signaller('peer:connected', data.id, data);

      // if the peer is existing, then update the data
      if (peer) {
        // update the data
        extend(peer.data, data);

        // trigger the peer update event
        return signaller('peer:update', data, srcData);
      }

      // create a new peer
      peer = {
        id: data.id,

        // initialise the local role index
        roleIdx: [data.id, signaller.id].sort().indexOf(data.id),

        // initialise the peer data
        data: {}
      };

      // initialise the peer data
      extend(peer.data, data);

      // set the peer data
      signaller.peers.set(data.id, peer);

      // if this is an initial announce message (no vector clock attached)
      // then send a announce reply
      if (signaller.autoreply && (! isDM)) {
        signaller
          .to(data.id)
          .send('/announce', signaller.attributes);
      }

      // emit a new peer announce event
      return signaller('peer:announce', data, peer);
    }
  };
};