index.js

const Wit = require('node-wit').Wit

module.exports = function (witToken) {
  return new Witbot(witToken)
}

function Witbot (witToken) {
  var self = this

  const actions = {
    say(sessionId, context, message, cb) {
      cb();
    },
    merge(sessionId, context, entities, message, cb) {
      cb(context);
    },
    error(sessionId, context, error) {
      console.log(error.message);
    },
  };

  self._wit = new Wit(witToken, actions)

  // process text with Wit.ai.
  // 1st argument is the text of the message
  // Remaining arguments will be passed as the first arguments of each registered callback
  self.process = function (text, context) {
    var args = Array.prototype.slice.call(arguments)
    var intents = new Intents()
    var matched = false
    args.shift()
    args.shift()
    self._wit.message(text, context, function (err, res) {
      if (err) return console.error('Wit.ai Error: ', err)

      // only consider the 1st outcome
      if (res.outcomes && res.outcomes.length > 0) {
        var outcome = res.outcomes[0]
        var intent = outcome.intent
        args.push(outcome)
        if (intents._intents[intent]) {
          intents._intents[intent].forEach(function (registration) {
            if (!matched && outcome.confidence >= registration.confidence) {
              matched = true
              registration.fn.apply(undefined, args)
            }
          })
        } else if (intents._any) {
          matched = true
          intents._any.apply(undefined, args)
        }
      }

      // there were no matched outcomes or matched routes
      if (!matched) intents._catchall.apply(undefined, args)
    })

    return intents
  }
}

function Intents () {
  var self = this
  self._intents = {}
  self._catchall = function () {}

  self.hears = function (name, confidence, fn) {
    var registration = {
      confidence: confidence,
      fn: fn
    }
    if (!self._intents[name]) {
      self._intents[name] = [registration]
    } else {
      self._intents[name].push(registration)
    }
    return self
  }

  self.otherwise = function (fn) {
    self._catchall = fn
    return self
  }

  self.any = function (fn) {
    self._any = fn
    return self
  }
}