module.exports = SessionSockets;

function SessionSockets(io, sessionStore, cookieParser, key) {
  key = typeof key === 'undefined' ? 'connect.sid' : key;
  var sessionSockets = this;

  this.on = function(event, callback) {
    return bind(event, callback, io.sockets);
  };

  this.of = function(namespace) {
    return {
      on: function(event, callback) {
        return bind(event, callback, io.of(namespace));
      }
    };
  };

  this.getSession = function(socket, callback) {
    cookieParser(socket.handshake, {}, function () {
      sessionStore.load(findCookie(socket.handshake), function (session) {
        callback(session);
      });
    });
  };

  function bind(event, callback, namespace) {
    namespace.on(event, function (socket) {
      sessionSockets.getSession(socket, function (session) {
        callback(socket, session);
      });
    });
  }

  function findCookie(handshake) {
    if (handshake)
      return (handshake.secureCookies && handshake.secureCookies[key]) ||
             (handshake.signedCookies && handshake.signedCookies[key]) ||
             (handshake.cookies && handshake.cookies[key]);
  }

}