socketstream/socketstream

// Engine.io client-side Wrapper
'use strict';

var reconnectSwitch = false;
var reconnectionTimeout = 1000;

module.exports = function(serverStatus, message, config){

  if (JSON.stringify(config) === '{}') {
    config = { 
        secure  : document.location.protocol === "https:"
      , host    : document.location.hostname
      , port    : document.location.port
    };
  }

  return {
    connect: function(){
      var sock = new eio.Socket(config);

      sock.on('message', function(e) {
        var i, x, msg = e;

        // Attempt to get the responderId from each message
        if ((i = msg.indexOf('|')) > 0) {

          var responderId = msg.substr(0, i), 
                  content = msg.substr(i+1);

          switch (responderId) {

            // X = a system message
            case 'X':
              if (reconnectSwitch === false) {
                serverStatus.emit('ready');
              } else {
                reconnectionTimeout = 1000;
                serverStatus.emit('reconnect');
              }
              break;

            // 0 = incoming events
            // As events are so integral to SocketStream rather than breaking up the JSON message
            // sent over the event transport for efficiencies sake we append the meta data (typically 
            // the channel name) at the end of the JSON message after the final pipe | character
            case '0':
              if ( (x = content.lastIndexOf('|')) > 0) {
                var event = content.substr(0, x),
                     meta = content.substr(x+1);
                message.emit(responderId, event, meta);
              } else {
                console.error('Invalid event message received:', msg);
              }
              break;
            
            // All other messages are passed directly to the relevant Request Responder
            default:
              message.emit(responderId, content);
          }

        // EVERY message should have a responderId
        // If we can't find one, it's a malformed request
        } else {
          console.error('Invalid websocket message received:', msg);
        }

      });

      var attemptReconnect = function(time){
        setTimeout(function(){
          var ss = require('socketstream');
          ss.assignTransport(config);
          if (ss.server.event != "reconnect") {
            reconnectionTimeout *= 1.5;
          }
        }, time);
      };

      sock.on('close', function() {
        reconnectSwitch = true;
        serverStatus.emit('disconnect');
        attemptReconnect(reconnectionTimeout);
      });

      // Return a function which is used to send all messages to the server
      return function(msg){
        sock.send(msg)
      };
    }
  }
}