app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var bodyParser = require('body-parser');
var fs = require('fs');
// var schedule = require('node-schedule');
var antiSpam = require('socket-anti-spam');
var watchr = require('watchr');
var touch = require("touch")

var routes = require('./routes');
// var topicHandler = require(path.resolve(__dirname, 'lib', 'topic_handler.js'));

var app = express();
var server = require('http').Server(app);
var io = require('socket.io')(server);

// topicsLocation = path.resolve(__dirname, 'lib', 'topics.json');
// manualTopicsLocation = path.resolve(__dirname, 'lib', 'manual-topics.json');
spamStringsLocation = path.resolve(__dirname, 'lib', 'spam-strings');

// currTopic = {
//     "topic": "Loading...",
//     "url": null
// };

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
    extended: false
}));
app.use(express.static(path.join(__dirname, 'public')));

app.get('/', routes.index);

var antiSpam = new antiSpam({
    spamCheckInterval: 3000,
    spamMinusPointsPerInterval: 3,
    spamMaxPointsBeforeKick: 9,
    spamEnableTempBan: true,
    spamKicksBeforeTempBan: 3,
    spamTempBanInMinutes: 120,
    removeKickCountAfter: 1,
});

// Spam strings file management
var spamStrings = [];
// touch.sync(spamStringsLocation);
fs.readFile(spamStringsLocation, function(err, data) {
    if (err) throw err;
    spamStrings = data.toString().split("\n");
});

watchr.watch({
    path: spamStringsLocation,
    listener: function() {
        fs.readFile(spamStringsLocation, function(err, data) {
            if (err) throw err;
            spamStrings = data.toString().split("\n");
        });
    }
});

var recentMessageTimes = {}; // Recent message timestamps by socket ID
var lastMessages = {}; // Last message by user
var greyListStatuses = {}; // Timestamps of too much spamming by socket ID
var connectionsByIP = {}; // Number of connections by IP
var usertags = {}; // Nicknames by socket.id

numOfUsers = 0;
var messageColors = ["#FFFFFF", "#044B7F"];
io.on('connection', function(socket) {
    var userIp = socket.client.request.headers['x-forwarded-for'];

    for (var id in usertags) {
        if (socket.handshake.query.tag.length > 0 && usertags[id] ===
            socket.handshake.query.tag) {
            socket.disconnect();
            return;
        }
    }

    var tag = socket.handshake.query.tag.trim().replace(/\s/g, '');
    tag = tag.substr(0, 10);

    // Creates new number of connections for new users
    if (connectionsByIP[userIp]) {
        connectionsByIP[userIp]++;

        // If user connects 4th time with same IP, disallow
        if (connectionsByIP[userIp] > 3) {
            connectionsByIP[userIp]--;
            socket.disconnect();
            return;
        }
    }
    // Or simply increments number of connections
    else 
        connectionsByIP[userIp] = 1;

    usertags[socket.id] = tag;

    antiSpam.onConnect(socket);
    recentMessageTimes[socket.id] = [];
    greyListStatuses[socket.id] = [];

    numOfUsers++;
    io.emit('user count', numOfUsers);
    console.log("User connected, total: " + numOfUsers);

    socket.on("new message", function(message) {
        if (typeof(message) != 'string') {
            socket.disconnect();
            return;
        }

        var spamCheckMessage = message.toLowerCase().trim();

        if (spamStrings.indexOf(spamCheckMessage) > -1) {
            socket.disconnect();
            return;
        }

        for (i = 0; i < spamStrings.length; i++) {
            if (spamStrings[i].length && spamCheckMessage.indexOf(
                    spamStrings[i]) > -1) {
                socket.disconnect();
                return;
            }
        }

        // Soft anti-spam measures
        var recent = recentMessageTimes[socket.id];
        if (recent.length == 5 && recent[0] > Date.now() - 5000) {
            var greyListStatus = greyListStatuses[socket.id];
            if (greyListStatus.length == 5 && greyListStatus[0] >
                Date.now() - 5000) {
                console.log("Stop spamming");
                delete greyListStatuses[socket.id];
                socket.disconnect();
            } else {
                greyListStatus.push(new Date());
                if (greyListStatus.length > 5)
                    greyListStatus.shift();
            }

            console.log(greyListStatuses)
            return;
        }

        if (lastMessages[socket.id] == message)
            return;
        else
            lastMessages[socket.id] = message;

        // Message validation, randomized styling and broadcasts
        if (message.length > 0 && message.length < 100) {
            var top = getRandomInt(10, 85);
            var left = getRandomInt(2, 90);
            var fontSize = (message.length < 25) ?
                getRandomFloat(1, 2) : getRandomFloat(0.8, 1.3);
            var randomColorInd = getRandomInt(0, 1);
            var color = [messageColors[randomColorInd],
                messageColors[(randomColorInd) ? 0 : 1]
            ];
            var thisUsertag = usertags[socket.id];

            io.emit('new message', {
                "msg": message,
                "cssTop": top,
                "cssLeft": left,
                "cssFontSize": fontSize,
                "cssColor": color,
                "usertag": thisUsertag
            });
            // console.log("New message: " + message);
        }

        recent.push(new Date());
        if (recent.length > 5) {
            recent.shift();
        }
    });

    // On user disconnect
    socket.on('disconnect', function() {
        connectionsByIP[userIp]--;
        numOfUsers--;
        io.emit('user count', numOfUsers);
        console.log("User disconnected, total: " + numOfUsers);
        delete recentMessageTimes[socket.id];
        delete greyListStatuses[socket.id];
        delete lastMessages[socket.id];
        delete usertags[socket.id];
    });
});

// topicHandler.firstTimeSetup();

// topicHandler.topicsScheduler(function() {
//     broadcastTopic(topicHandler.getNextTopic());
// });

// var rule = new schedule.RecurrenceRule();
// rule.minute = [0, 15, 30, 45];
// var j = schedule.scheduleJob(rule, function() {
//     broadcastTopic(topicHandler.getNextTopic());
// });


// Some helper functions
// function broadcastTopic(topicObj) {
//     currTopic = topicObj;
//     io.emit('new topic', currTopic);
//     console.log("New topic: " + currTopic.title);
// }

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

function getRandomFloat(min, max) {
    return (Math.random() * (max - min) + min).toFixed(1);
}


// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});


module.exports = server;