CoreBot.js

/**
 * This is a module that makes a bot
 * It expects to receive messages via the botkit.receiveMessage function
 * These messages are expected to match Slack's message format.
 **/
var mustache = require('mustache');
var simple_storage = require(__dirname + '/storage/simple_storage.js');
var ConsoleLogger = require(__dirname + '/console_logger.js');
var LogLevels = ConsoleLogger.LogLevels;
var ware = require('ware');
var clone = require('clone');
var fs = require('fs');
var studio = require('./Studio.js');
var os = require('os');

function Botkit(configuration) {
    var botkit = {
        events: {}, // this will hold event handlers
        config: {}, // this will hold the configuration
        tasks: [],
        taskCount: 0,
        convoCount: 0,
        my_version: null,
        my_user_agent: null,
        memory_store: {
            users: {},
            channels: {},
            teams: {},
        }
    };

    botkit.utterances = {
        yes: new RegExp(/^(yes|yea|yup|yep|ya|sure|ok|y|yeah|yah)/i),
        no: new RegExp(/^(no|nah|nope|n)/i),
        quit: new RegExp(/^(quit|cancel|end|stop|done|exit|nevermind|never mind)/i)
    };

    // define some middleware points where custom functions
    // can plug into key points of botkits process
    botkit.middleware = {
        send: ware(),
        receive: ware(),
        spawn: ware(),
        heard: ware(),
        capture: ware(),
    };


    function Conversation(task, message) {

        this.messages = [];
        this.sent = [];
        this.transcript = [];

        this.context = {
            user: message.user,
            channel: message.channel,
            bot: task.bot,
        };

        this.events = {};

        this.vars = {};

        this.threads = {};
        this.thread = null;

        this.status = 'new';
        this.task = task;
        this.source_message = message;
        this.handler = null;
        this.responses = {};
        this.capture_options = {};
        this.startTime = new Date();
        this.lastActive = new Date();
        /** will be pointing to a callback which will be called after timeout,
         * conversation will be not be ended and should be taken care by callback
         */
        this.timeOutHandler = null;

        this.collectResponse = function(key, value) {
            this.responses[key] = value;
        };

        this.capture = function(response, cb) {

            var that = this;
            var capture_key = this.sent[this.sent.length - 1].text;
            botkit.middleware.capture.run(that.task.bot, response, that, function(err, bot, response, convo) {
                if (response.text) {
                    response.text = response.text.trim();
                } else {
                    response.text = '';
                }

                if (that.capture_options.key != undefined) {
                    capture_key = that.capture_options.key;
                }

                // capture the question that was asked
                // if text is an array, get 1st
                if (typeof(that.sent[that.sent.length - 1].text) == 'string') {
                    response.question = that.sent[that.sent.length - 1].text;
                } else if (Array.isArray(that.sent[that.sent.length - 1].text)) {
                    response.question = that.sent[that.sent.length - 1].text[0];
                } else {
                    response.question = '';
                }

                if (that.capture_options.multiple) {
                    if (!that.responses[capture_key]) {
                        that.responses[capture_key] = [];
                    }
                    that.responses[capture_key].push(response);
                } else {
                    that.responses[capture_key] = response;
                }

                if (cb) cb(response);
            });

        };

        this.handle = function(message) {

            that = this;
            this.lastActive = new Date();
            this.transcript.push(message);
            botkit.debug('HANDLING MESSAGE IN CONVO', message);
            // do other stuff like call custom callbacks
            if (this.handler) {
                this.capture(message, function(message) {
                    // if the handler is a normal function, just execute it!
                    // NOTE: anyone who passes in their own handler has to call
                    // convo.next() to continue after completing whatever it is they want to do.
                    if (typeof(that.handler) == 'function') {
                        that.handler(message, that);
                    } else {
                        // handle might be a mapping of keyword to callback.
                        // lets see if the message matches any of the keywords
                        var match, patterns = that.handler;
                        for (var p = 0; p < patterns.length; p++) {
                            if (patterns[p].pattern && botkit.hears_test([patterns[p].pattern], message)) {
                                botkit.middleware.heard.run(that.task.bot, message, function(err, bot, message) {
                                    patterns[p].callback(message, that);
                                });
                                return;
                            }
                        }

                        // none of the messages matched! What do we do?
                        // if a default exists, fire it!
                        for (var p = 0; p < patterns.length; p++) {
                            if (patterns[p].default) {
                                botkit.middleware.heard.run(that.task.bot, message, function(err, bot, message) {
                                    patterns[p].callback(message, that);
                                });
                                return;
                            }
                        }

                    }
                });
            } else {
                // do nothing
            }
        };

        this.setVar = function(field, value) {
            if (!this.vars) {
                this.vars = {};
            }
            this.vars[field] = value;
        };

        this.activate = function() {
            this.task.trigger('conversationStarted', [this]);
            this.task.botkit.trigger('conversationStarted', [this.task.bot, this]);
            this.status = 'active';
        };

        /**
         * active includes both ACTIVE and ENDING
         * in order to allow the timeout end scripts to play out
         **/
        this.isActive = function() {
            return (this.status == 'active' || this.status == 'ending');
        };

        this.deactivate = function() {
            this.status = 'inactive';
        };

        this.say = function(message) {
            this.addMessage(message);
        };

        this.sayFirst = function(message) {
            if (typeof(message) == 'string') {
                message = {
                    text: message,
                    channel: this.source_message.channel,
                };
            } else {
                message.channel = this.source_message.channel;
            }
            this.messages.unshift(message);
        };


        this.on = function(event, cb) {
            botkit.debug('Setting up a handler for', event);
            var events = event.split(/\,/g);
            for (var e in events) {
                if (!this.events[events[e]]) {
                    this.events[events[e]] = [];
                }
                this.events[events[e]].push(cb);
            }
            return this;
        };

        this.trigger = function(event, data) {
            if (this.events[event]) {
                for (var e = 0; e < this.events[event].length; e++) {
                    var res = this.events[event][e].apply(this, data);
                    if (res === false) {
                        return;
                    }
                }
            } else {
            }
        };

        // proceed to the next message after waiting for an answer
        this.next = function() {
            this.handler = null;
        };

        this.repeat = function() {
            if (this.sent.length) {
                this.messages.push(this.sent[this.sent.length - 1]);
            } else {
                // console.log('TRIED TO REPEAT, NOTHING TO SAY');
            }
        };

        this.silentRepeat = function() {
            return;
        };

        this.addQuestion = function(message, cb, capture_options, thread) {
            if (typeof(message) == 'string') {
                message = {
                    text: message,
                    channel: this.source_message.channel
                };
            } else {
                message.channel = this.source_message.channel;
            }

            if (capture_options) {
                message.capture_options = capture_options;
            }

            message.handler = cb;
            this.addMessage(message, thread);
        };


        this.ask = function(message, cb, capture_options) {
            this.addQuestion(message, cb, capture_options, this.thread || 'default');
        };

        this.addMessage = function(message, thread) {
            if (!thread) {
                thread = this.thread;
            }
            if (typeof(message) == 'string') {
                message = {
                    text: message,
                    channel: this.source_message.channel,
                };
            } else {
                message.channel = this.source_message.channel;
            }

            if (!this.threads[thread]) {
                this.threads[thread] = [];
            }
            this.threads[thread].push(message);

            // this is the current topic, so add it here as well
            if (this.thread == thread) {
                this.messages.push(message);
            }
        };

        // how long should the bot wait while a user answers?
        this.setTimeout = function(timeout) {
            this.task.timeLimit = timeout;
        };

        // For backwards compatibility, wrap gotoThread in its previous name
        this.changeTopic = function(topic) {
            this.gotoThread(topic);
        };

        this.hasThread = function(thread) {
            return (this.threads[thread] != undefined);
        };


        this.transitionTo = function(thread, message) {

            // add a new transition thread
            // add this new message to it
            // set that message action to execute the actual transition
            // then change threads to transition thread

            var num = 1;
            while (this.hasThread('transition_' + num)) {
                num++;
            }

            var threadname = 'transition_' + num;

            if (typeof(message) == 'string') {
                message = {
                    text: message,
                    action: thread
                };
            } else {
                message.action = thread;
            }

            this.addMessage(message, threadname);

            this.gotoThread(threadname);

        };

        this.gotoThread = function(thread) {
            this.thread = thread;

            if (!this.hasThread(thread)) {
                if (thread == 'default') {
                    this.threads[thread] = [];
                } else {
                    botkit.debug('WARN: gotoThread() to an invalid thread!', thread);
                    this.stop('unknown_thread');
                    return;
                }
            }

            this.messages = this.threads[thread].slice();

            this.handler = null;
        };

        this.combineMessages = function(messages) {
            if (!messages) {
                return '';
            }

            if (Array.isArray(messages) && !messages.length) {
                return '';
            }

            if (messages.length > 1) {
                var txt = [];
                var last_user = null;
                var multi_users = false;
                last_user = messages[0].user;
                for (var x = 0; x < messages.length; x++) {
                    if (messages[x].user != last_user) {
                        multi_users = true;
                    }
                }
                last_user = '';
                for (var x = 0; x < messages.length; x++) {
                    if (multi_users && messages[x].user != last_user) {
                        last_user = messages[x].user;
                        if (txt.length) {
                            txt.push('');
                        }
                        txt.push('<@' + messages[x].user + '>:');
                    }
                    txt.push(messages[x].text);
                }
                return txt.join('\n');
            } else {
                if (messages.length) {
                    return messages[0].text;
                } else {
                    return messages.text;
                }
            }
        };

        this.getResponses = function() {

            var res = {};
            for (var key in this.responses) {

                res[key] = {
                    question: this.responses[key].length ?
                     this.responses[key][0].question : this.responses[key].question,
                    key: key,
                    answer: this.extractResponse(key),
                };
            }
            return res;
        };

        this.getResponsesAsArray = function() {

            var res = [];
            for (var key in this.responses) {

                res.push({
                    question: this.responses[key].length ?
                     this.responses[key][0].question : this.responses[key].question,
                    key: key,
                    answer: this.extractResponse(key),
                });
            }
            return res;
        };


        this.extractResponses = function() {

            var res = {};
            for (var key in this.responses) {
                res[key] = this.extractResponse(key);
            }
            return res;
        };

        this.extractResponse = function(key) {
            return this.combineMessages(this.responses[key]);
        };

        this.replaceAttachmentTokens = function(attachments) {

            if (attachments && attachments.length) {
                for (var a = 0; a < attachments.length; a++) {
                    for (var key in attachments[a]) {
                        if (typeof(attachments[a][key]) == 'string') {
                            attachments[a][key] = this.replaceTokens(attachments[a][key]);
                        } else {
                            attachments[a][key] = this.replaceAttachmentTokens(attachments[a][key]);
                        }
                    }
                }
            } else {
                for (var a in attachments) {
                    if (typeof(attachments[a]) == 'string') {
                        attachments[a] = this.replaceTokens(attachments[a]);
                    } else {
                        attachments[a] = this.replaceAttachmentTokens(attachments[a]);
                    }
                }
            }

            return attachments;
        };


        this.replaceTokens = function(text) {

            var vars = {
                identity: this.task.bot.identity,
                responses: this.extractResponses(),
                origin: this.task.source_message,
                vars: this.vars,
            };

            var rendered = '';

            try {
                rendered = mustache.render(text, vars);
            } catch (err) {
                botkit.log('Error in message template. Mustache failed with error: ', err);
                rendered = text;
            };

            return rendered;
        };

        this.stop = function(status) {
            this.handler = null;
            this.messages = [];
            this.status = status || 'stopped';
            botkit.debug('Conversation is over with status ' + this.status);
            this.task.conversationEnded(this);
        };

        // was this conversation successful?
        // return true if it was completed
        // otherwise, return false
        // false could indicate a variety of failed states:
        // manually stopped, timed out, etc
        this.successful = function() {

            // if the conversation is still going, it can't be successful yet
            if (this.isActive()) {
                return false;
            }

            if (this.status == 'completed') {
                return true;
            } else {
                return false;
            }

        };

        this.cloneMessage = function(message) {
            // clone this object so as not to modify source
            var outbound = clone(message);

            if (typeof(message.text) == 'string') {
                outbound.text = this.replaceTokens(message.text);
            } else if (message.text) {
                outbound.text = this.replaceTokens(
                    message.text[Math.floor(Math.random() * message.text.length)]
                );
            }

            if (outbound.attachments) {
                outbound.attachments = this.replaceAttachmentTokens(outbound.attachments);
            }

            if (outbound.attachment) {

                // pick one variation of the message text at random
                if (outbound.attachment.payload.text && typeof(outbound.attachment.payload.text) != 'string') {
                    outbound.attachment.payload.text = this.replaceTokens(
                        outbound.attachment.payload.text[
                            Math.floor(Math.random() * outbound.attachment.payload.text.length)
                        ]
                    );
                }
                outbound.attachment = this.replaceAttachmentTokens([outbound.attachment])[0];
            }

            if (this.messages.length && !message.handler) {
                outbound.continue_typing = true;
            }

            if (typeof(message.attachments) == 'function') {
                outbound.attachments = message.attachments(this);
            }

            return outbound;
        };

        this.onTimeout = function(handler) {
            if (typeof(handler) == 'function') {
                this.timeOutHandler = handler;
            } else {
                botkit.debug('Invalid timeout function passed to onTimeout');
            }
        };

        this.tick = function() {
            var now = new Date();

            if (this.isActive()) {
                if (this.handler) {
                    // check timeout!
                    // how long since task started?
                    var duration = (now.getTime() - this.task.startTime.getTime());
                    // how long since last active?
                    var lastActive = (now.getTime() - this.lastActive.getTime());

                    if (this.task.timeLimit && // has a timelimit
                        (duration > this.task.timeLimit) && // timelimit is up
                        (lastActive > this.task.timeLimit) // nobody has typed for 60 seconds at least
                    ) {
                        // if timeoutHandler is set then call it, otherwise follow the normal flow
                        // this will not break others code, after the update
                        if (this.timeOutHandler) {
                            this.timeOutHandler(this);
                        } else if (this.hasThread('on_timeout')) {
                            this.status = 'ending';
                            this.gotoThread('on_timeout');
                        } else {
                            this.stop('timeout');
                        }
                    }
                    // otherwise do nothing
                } else {
                    if (this.messages.length) {

                        if (this.sent.length &&
                            !this.sent[this.sent.length - 1].sent
                        ) {
                            return;
                        }

                        if (this.task.bot.botkit.config.require_delivery &&
                            this.sent.length &&
                            !this.sent[this.sent.length - 1].delivered
                        ) {
                            return;
                        }

                        if (typeof(this.messages[0].timestamp) == 'undefined' ||
                            this.messages[0].timestamp <= now.getTime()) {
                            var message = this.messages.shift();
                            //console.log('HANDLING NEW MESSAGE',message);
                            // make sure next message is delayed appropriately
                            if (this.messages.length && this.messages[0].delay) {
                                this.messages[0].timestamp = now.getTime() + this.messages[0].delay;
                            }
                            if (message.handler) {
                                //console.log(">>>>>> SET HANDLER IN TICK");
                                this.handler = message.handler;
                            } else {
                                this.handler = null;
                                //console.log(">>>>>>> CLEARING HANDLER BECAUSE NO HANDLER NEEDED");
                            }
                            if (message.capture_options) {
                                this.capture_options = message.capture_options;
                            } else {
                                this.capture_options = {};
                            }

                            this.lastActive = new Date();

                            // is there any text?
                            // or an attachment? (facebook)
                            // or multiple attachments (slack)
                            if (message.text || message.attachments || message.attachment) {

                                var outbound = this.cloneMessage(message);
                                var that = this;

                                outbound.sent_timestamp = new Date().getTime();

                                that.sent.push(outbound);
                                that.transcript.push(outbound);

                                this.task.bot.reply(this.source_message, outbound, function(err, sent_message) {
                                    if (err) {
                                        botkit.log('An error occurred while sending a message: ', err);

                                        // even though an error occured, set sent to true
                                        // this will allow the conversation to keep going even if one message fails
                                        // TODO: make a message that fails to send _resend_ at least once
                                        that.sent[that.sent.length - 1].sent = true;
                                        that.sent[that.sent.length - 1].api_response = err;

                                    } else {

                                        that.sent[that.sent.length - 1].sent = true;
                                        that.sent[that.sent.length - 1].api_response = sent_message;

                                        // if sending via slack's web api, there is no further confirmation
                                        // so we can mark the message delivered
                                        if (that.task.bot.type == 'slack' && sent_message && sent_message.ts) {
                                            that.sent[that.sent.length - 1].delivered = true;
                                        }

                                        that.trigger('sent', [sent_message]);

                                    }
                                });
                            }
                            if (message.action) {
                                if (typeof(message.action) == 'function') {
                                    message.action(this);
                                } else if (message.action == 'repeat') {
                                    this.repeat();
                                } else if (message.action == 'wait') {
                                    this.silentRepeat();
                                } else if (message.action == 'stop') {
                                    this.stop();
                                } else if (message.action == 'timeout') {
                                    this.stop('timeout');
                                } else if (this.threads[message.action]) {
                                    this.gotoThread(message.action);
                                }
                            }
                        } else {
                            //console.log('Waiting to send next message...');
                        }

                        // end immediately instad of waiting til next tick.
                        // if it hasn't already been ended by a message action!
                        if (this.isActive() && !this.messages.length && !this.handler) {
                            this.stop('completed');
                        }

                    } else if (this.sent.length) { // sent at least 1 message
                        this.stop('completed');
                    }
                }
            }
        };

        botkit.debug('CREATED A CONVO FOR', this.source_message.user, this.source_message.channel);
        this.gotoThread('default');
    };

    function Task(bot, message, botkit) {

        this.convos = [];
        this.botkit = botkit;
        this.bot = bot;

        this.events = {};
        this.source_message = message;
        this.status = 'active';
        this.startTime = new Date();

        this.isActive = function() {
            return this.status == 'active';
        };

        this.createConversation = function(message) {
            var convo = new Conversation(this, message);
            convo.id = botkit.convoCount++;
            this.convos.push(convo);
            return convo;
        };

        this.startConversation = function(message) {

            var convo = this.createConversation(message);
            botkit.log('>   [Start] ', convo.id, ' Conversation with ', message.user, 'in', message.channel);

            convo.activate();
            return convo;
        };

        this.conversationEnded = function(convo) {
            botkit.log('>   [End] ', convo.id, ' Conversation with ',
                       convo.source_message.user, 'in', convo.source_message.channel);
            this.trigger('conversationEnded', [convo]);
            this.botkit.trigger('conversationEnded', [bot, convo]);
            convo.trigger('end', [convo]);
            var actives = 0;
            for (var c = 0; c < this.convos.length; c++) {
                if (this.convos[c].isActive()) {
                    actives++;
                }
            }
            if (actives == 0) {
                this.taskEnded();
            }

        };

        this.endImmediately = function(reason) {

            for (var c = 0; c < this.convos.length; c++) {
                if (this.convos[c].isActive()) {
                    this.convos[c].stop(reason || 'stopped');
                }
            }

        };

        this.taskEnded = function() {
            botkit.log('[End] ', this.id, ' Task for ',
                this.source_message.user, 'in', this.source_message.channel);

            this.status = 'completed';
            this.trigger('end', [this]);

        };

        this.on = function(event, cb) {
            botkit.debug('Setting up a handler for', event);
            var events = event.split(/\,/g);
            for (var e in events) {
                if (!this.events[events[e]]) {
                    this.events[events[e]] = [];
                }
                this.events[events[e]].push(cb);
            }
            return this;
        };

        this.trigger = function(event, data) {
            if (this.events[event]) {
                for (var e = 0; e < this.events[event].length; e++) {
                    var res = this.events[event][e].apply(this, data);
                    if (res === false) {
                        return;
                    }
                }
            }
        };


        this.getResponsesByUser = function() {

            var users = {};

            // go through all conversations
            // extract normalized answers
            for (var c = 0; c < this.convos.length; c++) {

                var user = this.convos[c].source_message.user;
                users[this.convos[c].source_message.user] = {};
                var convo = this.convos[c];
                users[user] = convo.extractResponses();
            }

            return users;

        };

        this.getResponsesBySubject = function() {
            var answers = {};

            // go through all conversations
            // extract normalized answers
            for (var c = 0; c < this.convos.length; c++) {
                var convo = this.convos[c];

                for (var key in convo.responses) {
                    if (!answers[key]) {
                        answers[key] = {};
                    }
                    answers[key][convo.source_message.user] = convo.extractResponse(key);
                }
            }

            return answers;
        };

        this.tick = function() {

            for (var c = 0; c < this.convos.length; c++) {
                if (this.convos[c].isActive()) {
                    this.convos[c].tick();
                }
            }
        };
    };

    botkit.storage = {
        teams: {
            get: function(team_id, cb) {
                cb(null, botkit.memory_store.teams[team_id]);
            },
            save: function(team, cb) {
                botkit.log('Warning: using temporary storage. Data will be lost when process restarts.');
                if (team.id) {
                    botkit.memory_store.teams[team.id] = team;
                    cb(null, team.id);
                } else {
                    cb('No ID specified');
                }
            },
            all: function(cb) {
                cb(null, botkit.memory_store.teams);
            }
        },
        users: {
            get: function(user_id, cb) {
                cb(null, botkit.memory_store.users[user_id]);
            },
            save: function(user, cb) {
                botkit.log('Warning: using temporary storage. Data will be lost when process restarts.');
                if (user.id) {
                    botkit.memory_store.users[user.id] = user;
                    cb(null, user.id);
                } else {
                    cb('No ID specified');
                }
            },
            all: function(cb) {
                cb(null, botkit.memory_store.users);
            }
        },
        channels: {
            get: function(channel_id, cb) {
                cb(null, botkit.memory_store.channels[channel_id]);
            },
            save: function(channel, cb) {
                botkit.log('Warning: using temporary storage. Data will be lost when process restarts.');
                if (channel.id) {
                    botkit.memory_store.channels[channel.id] = channel;
                    cb(null, channel.id);
                } else {
                    cb('No ID specified');
                }
            },
            all: function(cb) {
                cb(null, botkit.memory_store.channels);
            }
        }
    };


    /**
     * hears_regexp - default string matcher uses regular expressions
     *
     * @param  {array}  tests    patterns to match
     * @param  {object} message message object with various fields
     * @return {boolean}        whether or not a pattern was matched
     */
    botkit.hears_regexp = function(tests, message) {
        for (var t = 0; t < tests.length; t++) {
            if (message.text) {

                // the pattern might be a string to match (including regular expression syntax)
                // or it might be a prebuilt regular expression
                var test = null;
                if (typeof(tests[t]) == 'string') {
                    try {
                        test = new RegExp(tests[t], 'i');
                    } catch (err) {
                        botkit.log('Error in regular expression: ' + tests[t] + ': ' + err);
                        return false;
                    }
                    if (!test) {
                        return false;
                    }
                } else {
                    test = tests[t];
                }

                if (match = message.text.match(test)) {
                    message.match = match;
                    return true;
                }
            }
        }
        return false;
    };


    /**
     * changeEars - change the default matching function
     *
     * @param  {function} new_test a function that accepts (tests, message) and returns a boolean
     */
    botkit.changeEars = function(new_test) {
        botkit.hears_test = new_test;
    };


    botkit.hears = function(keywords, events, middleware_or_cb, cb) {

        // the third parameter is EITHER a callback handler
        // or a middleware function that redefines how the hear works
        var test_function = botkit.hears_test;
        if (cb) {
            test_function = middleware_or_cb;
        } else {
            cb = middleware_or_cb;
        }

        if (typeof(keywords) == 'string') {
            keywords = [keywords];
        }
        if (typeof(events) == 'string') {
            events = events.split(/\,/g);
        }

        for (var e = 0; e < events.length; e++) {
            (function(keywords, test_function) {
                botkit.on(events[e], function(bot, message) {
                    if (test_function && test_function(keywords, message)) {
                        botkit.debug('I HEARD', keywords);
                        botkit.middleware.heard.run(bot, message, function(err, bot, message) {
                            cb.apply(this, [bot, message]);
                            botkit.trigger('heard_trigger', [bot, keywords, message]);
                        });
                        return false;
                    }
                });
            })(keywords, test_function);
        }

        return this;
    };

    botkit.on = function(event, cb) {
        botkit.debug('Setting up a handler for', event);
        var events = (typeof(event) == 'string') ? event.split(/\,/g) : event;

        for (var e in events) {
            if (!this.events[events[e]]) {
                this.events[events[e]] = [];
            }
            this.events[events[e]].push(cb);
        }
        return this;
    };

    botkit.trigger = function(event, data) {
        if (this.events[event]) {
            for (var e = 0; e < this.events[event].length; e++) {
                var res = this.events[event][e].apply(this, data);
                if (res === false) {
                    return;
                }
            }
        }
    };

    botkit.startConversation = function(bot, message, cb) {
        botkit.startTask(bot, message, function(task, convo) {
            cb(null, convo);
        });
    };

    botkit.createConversation = function(bot, message, cb) {

        var task = new Task(bot, message, this);

        task.id = botkit.taskCount++;

        var convo = task.createConversation(message);

        this.tasks.push(task);

        cb(null, convo);

    };


    botkit.defineBot = function(unit) {
        if (typeof(unit) != 'function') {
            throw new Error('Bot definition must be a constructor function');
        }
        this.worker = unit;
    };

    botkit.spawn = function(config, cb) {


        var worker = new this.worker(this, config);
        // mutate the worker so that we can call middleware
        worker.say = function(message, cb) {
            botkit.middleware.send.run(worker, message, function(err, worker, message) {
                if (err) {
                    botkit.log('Error in worker.say: ' + err);
                } else {
                    worker.send(message, cb);
                }
            });
        };
        botkit.middleware.spawn.run(worker, function(err, worker) {
            if (err) {
                botkit.log('Error in middlware.spawn.run: ' + err);
            } else {
                botkit.trigger('spawned', [worker]);

                if (cb) { cb(worker); }
            }
        });

        return worker;
    };

    botkit.startTicking = function() {
        if (!botkit.tickInterval) {
            // set up a once a second tick to process messages
            botkit.tickInterval = setInterval(function() {
                botkit.tick();
            }, 1500);
        }
    };

    botkit.shutdown = function() {
        if (botkit.tickInterval) {
            clearInterval(botkit.tickInterval);
        }
    };

    botkit.startTask = function(bot, message, cb) {


        var task = new Task(bot, message, this);

        task.id = botkit.taskCount++;
        botkit.log('[Start] ', task.id, ' Task for ', message.user, 'in', message.channel);

        var convo = task.startConversation(message);

        this.tasks.push(task);

        if (cb) {
            cb(task, convo);
        } else {
            return task;
        }

    };

    botkit.receiveMessage = function(bot, message) {
        botkit.middleware.receive.run(bot, message, function(err, bot, message) {
            if (err) {
                botkit.log('ERROR IN RECEIVE MIDDLEWARE: ', err);
            } else {
                botkit.debug('RECEIVED MESSAGE');
                bot.findConversation(message, function(convo) {
                    if (convo) {
                        convo.handle(message);
                    } else {
                        botkit.trigger('message_received', [bot, message]);
                    }
                });
            }
        });
    };

    botkit.tick = function() {
        for (var t = 0; t < botkit.tasks.length; t++) {
            botkit.tasks[t].tick();
        }
        for (var t = botkit.tasks.length - 1; t >= 0; t--) {
            if (!botkit.tasks[t].isActive()) {
                botkit.tasks.splice(t, 1);
            }
        }


        this.trigger('tick', []);

    };


    /**
     * Define a default worker bot. This function should be customized outside
     * of Botkit and passed in as a parameter by the developer
     **/
    botkit.worker = function(botkit, config) {
        this.botkit = botkit;
        this.config = config;

        this.say = function(message, cb) {
            botkit.debug('SAY:', message);
        };

        this.replyWithQuestion = function(message, question, cb) {

            botkit.startConversation(message, function(convo) {
                convo.ask(question, cb);
            });

        };

        this.reply = function(src, resp) {
            botkit.debug('REPLY:', resp);
        };


        this.findConversation = function(message, cb) {
            botkit.debug('DEFAULT FIND CONVO');
            cb(null);
        };
    };

    botkit.userAgent = function() {

        if (!botkit.my_user_agent) {
            // set user agent to Botkit
            var ua = 'Botkit/' + botkit.version();

            // add OS info
            ua = ua + ' ' + os.platform() + '/' + os.release();

            // add Node info
            ua = ua + ' ' + 'node/' + process.version.replace('v', '');

            botkit.my_user_agent = ua;
        }

        return botkit.my_user_agent;

    };


    botkit.version = function() {

        if (!botkit.my_version) {
            var pkg = fs.readFileSync(__dirname + '/../package.json');
            try {
                pkg = JSON.parse(pkg);
            } catch (err) {
                throw new Error('Could not determine Botkit version', err);
            }

            botkit.my_version = pkg.version;
        }
        return botkit.my_version;

    };


    botkit.config = configuration;

    /** Default the application to listen to the 0.0.0.0, the default
      * for node's http module. Developers can specify a hostname or IP
      * address to override this.
    **/
    if (!botkit.config.hostname) {
        botkit.config.hostname = '0.0.0.0';
    };


    if (!configuration.logLevel) {
        if (configuration.debug) {
            configuration.logLevel = 'debug';
        } else if (configuration.log === false) {
            configuration.logLevel = 'error';
        } else {
            configuration.logLevel = 'info';
        }
    }

    if (configuration.logger) {
        if (typeof configuration.logger.log === 'function') {
            botkit.logger = configuration.logger;
        } else {
            throw new Error('Logger object does not have a `log` method!');
        }
    } else {
        botkit.logger = ConsoleLogger(console, configuration.logLevel);
    }

    botkit.log = function() {
        botkit.log.info.apply(botkit.log, arguments);
    };
    Object.keys(LogLevels).forEach(function(level) {
        botkit.log[level] = botkit.logger.log.bind(botkit.logger, level);
    });
    botkit.debug = botkit.log.debug;

    console.log('Initializing Botkit v' + botkit.version());

    if (configuration.storage) {
        if (
            configuration.storage.teams &&
            configuration.storage.teams.get &&
            configuration.storage.teams.save &&

            configuration.storage.users &&
            configuration.storage.users.get &&
            configuration.storage.users.save &&

            configuration.storage.channels &&
            configuration.storage.channels.get &&
            configuration.storage.channels.save
        ) {
            botkit.log('** Using custom storage system.');
            botkit.storage = configuration.storage;
        } else {
            throw new Error('Storage object does not have all required methods!');
        }
    } else if (configuration.json_file_store) {
        botkit.log('** Using simple storage. Saving data to ' + configuration.json_file_store);
        botkit.storage = simple_storage({path: configuration.json_file_store});
    } else {
        botkit.log('** No persistent storage method specified! Data may be lost when process shuts down.');
    }

    // set the default set of ears to use the regular expression matching
    botkit.changeEars(botkit.hears_regexp);

    //enable Botkit Studio
    studio(botkit);

    return botkit;
}

module.exports = Botkit;