dispatcher.js

'use strict';

var logger = require('winston'),

  MemoryDataStore = require('@slack/client').MemoryDataStore,
  dataStore = new MemoryDataStore(),

  util = {
    config: require('./util/config'),
    command: require('./util/command')
  },

  path = require('path'),

  handlers,
  commands,
  slackClient;

/**
 * Get dispatcher status
 *
 * @return boolean
 */
var isInitialized = function() {
  return handlers !== undefined && handlers.length > 0;
}

/**
 * Reads commands.json from CONFIG_DIR and sets up handlers.
 * Handlers are expected to have the same name as the command, i.e.
 * of the pattern {command-name}.js
 *
 * @param  { object } Slack client
 * @return { none }
 *
 */
var init = function (client) {
  slackClient = client;
  handlers = {};

  util.command.init();

  commands = require(path.resolve(util.config.get('CONFIG_DIR'), 'commands'));

  Object.keys(commands).forEach(function (command) {
    handlers[command] = require(path.resolve(util.config.get('COMMAND_DIR'), command));
  });

  logger.info('Command dispatcher initialized');
};

/**
 * Processes, using helpers, the user message posted and calls the appropriate command,
 * passing it an object with four parameters: the channel posted, the user posting,
 * the command entered by the user and the additional text as an array of tokens(args).
 * If no matching command is found, looks for and calls file named after the ERROR_COMMAND
 * config parameter set on initialization.
 *
 * @param  { string } message posted by a user in Slack channel
 * @return { none }
 */
var handle = function (msg) {
  var data;

  // gets command and args parameters
  data = util.command.parse(msg);

  data.user = msg.user;
  data.channel = msg.channel;
  data.commandConfig = commands[data.command];

  // respond only for non-bot user messages
  if (data.user && !slackClient.dataStore.getUserById(data.user).is_bot) {
    if (!handlers[data.command]) {
      throw new Error('Command ' + data.command + ' not found in ' + util.config.get('COMMAND_DIR') + ' directory');
    }

    handlers[data.command](data);
  }
};

exports.init            = init;
exports.handle          = handle;
exports.isInitialized   = isInitialized;