index.js

'use strict';
var q = require('q');
var express = require('express');
var bodyParser = require('body-parser');
var request = require('request');
var fs = require('fs');
var path = require('path');
var chat = require('./chat_utils.js')
var array_utils = require('./utils.js').arrays;

/// import relevant plugins
var minerva_search = require('./plugins').minerva_search;
var help = require('./plugins').help;
var conversation = require('./plugins').conversation;
var showmore = require('./plugins').showmore;
var catalog_search = require('./plugins').catalog_search;
var major_search = require('./plugins').major_search;
var building_search = require('./plugins').building_search;
var uprint_search = require('./plugins').uprint_search;

// set up web server
var app = express();
app.set('port', ( process.env.PORT || process.env.OPENSHIFT_NODEJS_PORT || 5000 ) );
app.set('ip', ( process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1') );

app.use(function(req,res,next){
    var _send = res.send;
    var sent = false;
    res.send = function(data){
        if(sent) return;
        _send.bind(res)(data);
        sent = true;
    };
    next();
});

// Process application/x-www-form-urlencoded
app.use( bodyParser.urlencoded( { extended:false} ) );
app.use( bodyParser.json() );


// context management:
var contexts;
try{
	contexts = JSON.parse(fs.readFileSync(path.resolve( ( process.env.OPENSHIFT_DATA_DIR || './' ), 'history.json'), 'utf8')).contexts || {};
}catch(err){
	contexts = {};
}

function get_or_create_context(user){
	if(!contexts[user]){
		contexts[user] = {extracted:[], fails:0};
	} 
	return contexts[user];
}

chat.menu([
	['postback', 'Help', 'help@'],
	['web_url', 'Source Code (V0.2.1)', 'https://github.com/zafarali/minerva-bot/']
	])
app.get('/', function (req, res) { 

		// storage.push(req.query['to_push']);
		res.send({message:'minerva bot backend!'});

});


app.get('/webhook', function (req, res) {
		//  USED FOR SET UP:
	if(req.query['hub.verify_token'] == process.env['VERIFYTOKEN']) {
		res.send(req.query['hub.challenge']);
	}
	res.send('Error, wrong token');
});


app.post('/webhook/', function (req, res) {
	// handles messages and postbacks

	var messaging_events = req.body.entry[0].messaging;

	for(var i=0; i < messaging_events.length; i++){
		var event = messaging_events[i];
		var sender = event.sender.id;

		// handle explicit text messaging events or postbacks
		if( (event.message && event.message.text ) 
			|| (event.postback && event.postback.payload ) ){

			// set a welcome message
			try{
				chat.welcome();
			}catch(e){
				console.log('Error setting welcome message.')
			}

			chat.set_state(sender, 'mark_seen');

			var query, postback;

			if(event.postback){
				query = '' // if postback is defined, then query must be blank
				postback = event.postback.payload;
			}else{
				query = event.message.text;
				postback = '' // message is defined, then postback must be blank
				if(event.message.quick_reply){
					postback = event.message.quick_reply.payload // handle new payload type
				}
			}

			console.log('query recieved:', query);
			console.log('postback recieved:', postback);

			internals(query, sender, postback).then(function(ctx){

				console.log('response computed.');
				
				chat.set_state(sender, 'typing_on')

				if(ctx.replies.length === 0){
					ctx.history.fails = ctx.history.fails + 1;					
					ctx.replies.push(
						array_utils.random_choice(
							[
							'I don\'t understand what you\'re asking me :(. I\'m always improving.', 
							'Didn\'t get that.', 
							'What was that?', 
							'Hmm.. not sure what you are asking me about...',
							'Ask me something more descriptive?' ]
							)
						);
				}else{
					ctx.history.fails = 0;
				}

				if(ctx.history.fails>1){
					console.log('Person needs help!!')
					ctx.replies.push(
						chat.builders.quick_reply(
							array_utils.random_choice(
								['You seem confused. ', 'Are you confused? ', 'Seems like we aren\'t on the same page. ']
								) + 
							array_utils.random_choice(
								['Try asking me for HELP?', 'Ask me to HELP you?', 'Would you like me to HELP you?', 'Type HELP to see what I can do!']
								),
							[['Help', 'help@'],['Nah', 'negative@']]
						));
				}

				// schedule replies every 200ms
				chat.reply2(sender,ctx.replies)


			}).then(function(){
				chat.set_state(sender, 'typing_off')
				console.log('reply chain complete');

			}).catch(function(err){
				chat.set_state(sender, 'typing_off')
				console.log('error occured:',err)
				chat.reply2(sender, ["Something went wrong... Try again!"]);
				// res.send({error:err});
			});
		}
	}

	res.sendStatus(200);

});


// internal chain logic for the purposes of abstraction
function internals(query, user, postback){

	// plugins to be executed
	var to_execute = [ conversation, help, uprint_search, building_search, showmore, minerva_search, catalog_search, major_search ];

	// obtain a context
	var history = get_or_create_context(user);
	
	var context = {
		history: history,
		current_query: query,
		postback:postback,
		completed: false,
		replies:[]
	}
	
	return to_execute.reduce(q.when, q(context));
}


app.get('/dump_history/', function(req, res){
	// dumps all user contexts to the file system and out
	// only works if the token query is correct
	// for "security" 
	if(req.query['token'] == process.env['VERIFYTOKEN']) {
		// dumps all user contexts to the file system and out
		var contexts_string = JSON.stringify({contexts:contexts});
		try{
			fs.writeFile( ( process.env.OPENSHIFT_DATA_DIR || './' )+'history.json', contexts_string, function (err) {
				if (err) throw err;
				console.log('Saved 1');
			});
		}catch(err){
			fs.writeFile( ( process.env.OPENSHIFT_DATA_DIR +'/' || './' )+'history.json', contexts_string, function (err) {
				if (err) throw err;
				console.log('Saved 2');
			});
		}

		res.send({contexts:contexts});
	}
});

app.listen( app.get('port'), app.get('ip'), function() {
	console.log('listening on', app.get('ip'), ' on port ', app.get('port') );
});