namespace.js

/**
 * socket.io
 * Copyright(c) 2011 LearnBoost <dev@learnboost.com>
 * MIT Licensed
 */

(function (exports, io) {

  /**
   * Expose constructor.
   */

  exports.SocketNamespace = SocketNamespace;

  /**
   * Socket namespace constructor.
   *
   * @constructor
   * @api public
   */

  function SocketNamespace (socket, name) {
    this.socket = socket;
    this.name = name || '';
    this.flags = {};
    this.json = new Flag(this, 'json');
    this.ackPackets = 0;
    this.acks = {};
  };

  /**
   * Apply EventEmitter mixin.
   */

  io.util.mixin(SocketNamespace, io.EventEmitter);

  /**
   * Copies emit since we override it
   *
   * @api private
   */

  SocketNamespace.prototype.$emit = io.EventEmitter.prototype.emit;

  /**
   * Sends a packet.
   *
   * @api private
   */

  SocketNamespace.prototype.packet = function (packet) {
    packet.endpoint = this.name;
    this.socket.packet(packet);
    this.flags = {};
    return this;
  };

  /**
   * Sends a message
   *
   * @api public
   */

  SocketNamespace.prototype.send = function (data, fn) {
    var packet = {
        type: this.flags.json ? 'json' : 'message'
      , data: data
    };

    if ('function' == typeof fn) {
      packet.id = ++this.ackPackets;
      packet.ack = fn.length ? 'data' : true;
      this.acks[packet.id] = fn;
    }

    return this.packet(packet);
  };

  /**
   * Emits an event
   *
   * @api public
   */
  
  SocketNamespace.prototype.emit = function (name) {
    var args = Array.prototype.slice.call(arguments, 1)
      , lastArg = args[args.length - 1]
      , packet = {
            type: 'event'
          , name: name
        };

    if ('function' == typeof lastArg) {
      packet.id = ++this.ackPackets;
      packet.ack = lastArg.length ? 'data' : true;
      this.acks[packet.id] = lastArg;
      args = args.slice(0, args.length - 1);
    }

    packet.args = args;

    return this.packet(packet);
  };

  /**
   * Handles a packet
   *
   * @api private
   */

  SocketNamespace.prototype.onPacket = function (packet) {
    var dataAck = packet.ack == 'data'
      , self = this;

    function ack () {
      self.packet({
          type: 'ack'
        , args: io.util.toArray(arguments)
        , ackId: packet.id
      });
    };

    switch (packet.type) {
      case 'connect':
      case 'disconnect':
        this.$emit(packet.type);
        break;

      case 'message':
      case 'json':
        var params = ['message', packet.data];

        if (dataAck)
          params.push(ack);

        this.emit.apply(socket, params);
        break;

      case 'event':
        var params = [packet.name].concat(packet.args);

        if (dataAck)
          params.push(ack);

        this.$emit.apply(this, params);
        break;

      case 'ack':
        if (this.acks[packet.ackId]) {
          this.acks[packet.ackId].apply(this, packet.args);
        }
    }
  };

  /**
   * Flag interface.
   *
   * @api private
   */

  function Flag (nsp, name) {
    this.namespace = nsp;
    this.name = name;
  };

  /**
   * Send a message
   *
   * @api public
   */

  Flag.prototype.send = function () {
    this.namespace.flags[this.name] = true;
    this.namespace.send.apply(this, arguments);
  };

  /**
   * Emit an event
   *
   * @api public
   */

  Flag.prototype.emit = function () {
    this.namespace.flags[this.name] = true;
    this.namespace.emit.apply(this, arguments);
  };

})(
    'undefined' != typeof io ? io : module.exports
  , 'undefined' != typeof io ? io : module.parent.exports
);