app.js

var express = require("express");
var app     = express();
var async   = require("async");
var db      = require("mongojs")("mongodb://localhost/datamining", ["tuples", "classifier"]);
var util    = require('util');
var hbs     = require('hbs');
var logger  = require("./lib/logger.js").Logger('app.js', false);



var defaultResponse = {
    hostname: process.env.HOSTNAME || "0.0.0.0",
    port    : process.env.PORT || null
};

logger.info("Starting...");

//set view manager to Handlebar.js
app.set('view engine', 'hbs');
hbs.registerPartials(__dirname + '/views/partials');
hbs.registerHelper('json', function (data) {
    return JSON.stringify(data);
});

//Login for each request.
app.use(require('morgan')('dev'));

//set up public directory to hold assets.
app.use('/public', require('serve-static')('public'));

//Expects attributes to be given in the query field of the request.

app.get("/", function (req, res) {
    res.render('index', defaultResponse);
});

app.get("/index", function (req, res) {
    res.render('index', defaultResponse);
});


app.get("/minedata", function (req, res) {
    res.render('minedata', defaultResponse);
});

app.get("/student", function (req, res) {
    res.render('student', defaultResponse);
});

app.get("/student_done", function (req, res) {
    res.render('student_done', defaultResponse);
});

app.get("/instructor", function (req, res) {
    res.render('instructor', defaultResponse);
});

app.get("/maintenance", function (req, res) {
    res.render('maintenance', {});
});

app.route("/classifier/:id").post(function (req, res) {

    //1. Check that this classifier doesn't exists....
    //    - Not currently implemented.
    //2. Push the entry into the database.

    logger.warn("POST: /classifier/" + req.params.id);

    db.classifier.find(
        {
            "classifier": req.params.id
        },
        function (err, data) {

            if (err) {
                logger.error(err);
                res.status(500);
                return res.send("ERROR!");
            }
            if (data.length > 0) {

                res.status(403);
                return res.send("CLASSIFIER EXISTS");

            }

            db.classifier.insert(
                {
                    "classifier": req.params.id,
                    "attributes": req.query.attr
                },
                function (err, data) {

                    if (err) {
                        logger.error(err);
                        res.status(500);
                        return res.send("ERROR");
                    }

                    res.status(200);
                    return res.send("OK");
                }
            );

        }
    );


});


app.get("/data/:id", function (req, res) {

    logger.warn("GET: /data/" + req.params.id);

    var result = [];
    var flag   = false;
    setTimeout(function () {
        if (!flag) {
            res.status(408);
            res.send("TIMEOUT!");
        }
    }, 3000);

    async.each(
        [req.params.id],
        function (item, callback) {
            db.tuples.find({"classifier": item}, function (err, data) {

                if (data.length <= 0) {

                    //logger.info(util.inspect(data, false, null));

                    result.push([]);
                    return callback(204); //respond with no-data

                } else {

                    result.push(data);
                    return callback(); //indicate we are done to the async library.

                }


            });
        },
        function (err) {

            if (err) {

                flag = true;

                if (err === 204) {

                    res.status(204);
                    return res.send("NO DATA");

                } else {

                    res.status(500);
                    return res.send("ERROR");

                }

            }

            res.status(200);
            flag = true;
            return res.send(JSON.stringify(result));
        }
    );
});


/*
 * Takes in a classifier_id (via url REST) and then a
 * sequence of values via the "query" of the req.
 *
 * 1. Push the data in the into Mongo.tuples using the keys
 *     of the query as the keys into Mongo.
 * 2. Craft response message.
 */
app.post("/data/:id", function (req, res) {

    logger.warn("POST: /data/" + req.params.id);

    var fromClient = "";

    req.on('data', function (d) {

        fromClient += d;

    });

    req.on('end', function () {

        try {

            fromClient = JSON.parse(fromClient);


            async.each(
                fromClient,
                function (item, cb) {

                    db.tuples.insert(
                        {
                            "classifier": req.params.id,
                            "data"      : item,
                        },
                        function (err, data) {

                            if (err) {

                                cb();

                            }
                            ;

                            cb();
                        }
                    );

                }, function (err) {

                    res.status(200);
                    return res.send();

                }
            );


        } catch (e) {

            res.status(400);
            return res.send("COULD NOT PARSE INPUT");

        }

    });


});

var server = app.listen(process.env.PORT || 3000, '0.0.0.0', function () {
    var host = server.address().address;
    var port = server.address().port;
    logger.info("App running at: http://" + host + ":" + port);
});