{
    "ID": 0 // a number indicating which function to call
    "msg": "{
            // embedded JSON contains the data
            .....
            }"
}

/* Library to add date and time to any console.log */
    require('log-timestamp');
    /* Asynchronous JSON parse library */
    var parseJSON = require('json-parse-async');
    /* Asynchronous JSON stringify library */
    var asyncJSON = require('async-json');
    /* Keymetrics advance metrics */
    var pmx = require('pmx').init({
        http: false, // HTTP routes logging (default: true)
        ignore_routes: [], // Ignore http routes (Default: [])
        errors: true, // Exceptions loggin (default: true)
        custom_probes: false, // Auto expose JS Loop Latency and HTTP req/s
        network: true, // Network monitoring at the application level
        ports: false // Shows which ports your app is listening on (default: false)
    });
    var probe = pmx.probe();
    // The counter will start at 0
    var counter = probe.counter({
        name: 'Current connected players'
    });
    /* Encryption situp */
    var crypto = require('crypto');
    var key = new Buffer([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32]);
    var iv = new Buffer([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
    var cipherAlgorithmUsed = 'aes-256-cbc';
    /* Encrypt buffer */
    function encrypt(textBuffer) {
        try {
            var cipher = crypto.createCipheriv(cipherAlgorithmUsed, key, iv);
            var crypted = Buffer.concat([cipher.update(textBuffer), cipher.final()]);
            return crypted;
        } catch (err) {
            // Handle the error here.
            console.error('Error trying to encrypt, ' + err);
            return '';
        }
        return '';
    }
    /* Decrypt buffer */
    function decrypt(encryptedBuffer) {
        try {
            var decipher = crypto.createDecipheriv(cipherAlgorithmUsed, key, iv);
            var dec = Buffer.concat([decipher.update(encryptedBuffer), decipher.final()]);
            return dec;
        } catch (err) {
            // Handle the error here.
            console.error('Error trying to decrypt, ' + err);
            return '';
        }
        return '';
    }
    /* Database Connection */
    var ConnectionPool = require('tedious-connection-pool');
    var DBTDSConnection = require('tedious').Connection;
    var Request = require('tedious').Request;
    var poolConfig = {
        min: 10, // The minimun of connections there can be in the pool. Default = 10
        max: 1000, //The maximum number of connections there can be in the pool. Default = 50
        log: false
    };
    var dBConnectionconfig = {
        userName: 'kskskhr@939jdn',
        password: 'kwpfnekososken',
        server: 'jjsmcmnxjfhsn.database.windows.net',
        options: {
            requestTimeout: 0,
            debug: {
                packet: false,
                data: false,
                payload: false,
                token: false,
                log: false
            },
            encrypt: true,// If you are on Microsoft Azure, you need this:
            database: 'ylldkgnje_db'
        }
    };
    //create the pool
    var pool = new ConnectionPool(poolConfig, dBConnectionconfig);
    pool.on('error', function(err) {
        console.error('Error when trying to create DB connection pool' + err);
    });
    /* Login Server */
    var net = require('net');
    var HOST = '127.0.0.1';
    var PORT = 4000; // nginx is used infront as a reverse proxy
    var server = net.createServer(); // Create a server instance
    server.listen(PORT, HOST);
    onClientConnected_ServerEvent = function(sock) {
            counter.inc(); // Increment the counter, metrics
            sock.on('data', function(data) { // data from client
                parseJSON(decrypt(data), function(err, content) {
                    if (err) {
                        console.error('Error when trying to parse json received from client, json received is ' + data + ', and the error is ' + err);
                        sock.end();
                    } else {
                        switch (content.reqID) {
                            case 0:
                                setPlayerData(sock, content.msg);
                                break;
                            case 1:
                                getPlayerData(sock, content.msg);
                                break;
                            case 2:
                                createUser(sock, content.msg);
                                break;
                            default:
                                console.log('request id sent doesnt match any of the cases, id sent is ' + content.reqID);
                                return;
                        }
                    }
                });
            });
            sock.on('close', function(data) {
                counter.dec(); // Decrement the counter, metrics
            });
            sock.on('timeout', function(data) {
            });
        }
        /*
        Emitted when an error occurs. The 'close' event will be called directly following this event. See example in discussion of server.listen.
        */
    onError_ServerEvent = function(err) {
        // handle errors here
        console.error('onError_ServerEvent occured, ' + err);
        throw err;
    }
    server.on('connection', onClientConnected_ServerEvent);
    server.on('error', onError_ServerEvent);
    var PlayerData = function() {
            this.appVersionAndroid = "2.7",
                this.appVersioniOS = "2.7",
                this.kickStatus = "true",
                this.maxNumOfPlayerInRoom = "10",
                this.userName = "potato",
                this.coin = 2311,
                this.ruby = 22,
                this.rep = 352,
                this.driftMax = 2133,
                this.dailyRepsGiveAway = 132,
                this.equipedProducts = "3-1-2-1,3-6-2-1,2-1-1-1",
                this.boughtProducts = "3-1-2-1,3-6-2-1,2-1-1-1";
        }
        // case 0
    function setPlayerData(sock, dataSent) { // update player data
        // parse json, then update player row in DB
        parseJSON(dataSent, function(err, playerDataSent) {
            if (err) {
                console.error('(setPlayerData) Error when trying to parse json received from switch statment, json received is ' + dataSent + ', and the error is ' + err);
            } else {
                pool.acquire(function(err, connection) { //acquire a db connection from connection pool
                    if (err) {
                        console.error('(setPlayerData) Error when trying to acquire a DB connection from pool,  ' + err);
                        return;
                    }
                    var sqlUpdatePlayerDataQuery = "UPDATE PlayerDataTable  SET rep=" + playerDataSent.rep + ", driftDistance=" + playerDataSent.driftMax + ", coin = " + playerDataSent.coin + ", ruby = " + playerDataSent.ruby + ", dailyReps = " + playerDataSent.dailyRepsGiveAway + ", boughtProducts = '" + playerDataSent.boughtProducts + "', equippedProducts = '" + playerDataSent.equipedProducts + "', lastUpdated = GETDATE() WHERE UserName ='" + playerDataSent.userName + "'";
                    var request = new Request(sqlUpdatePlayerDataQuery, function(err, rowCount) {
                        if (err) {
                            sock.write(encrypt('0'));
                            console.error('(setPlayerData) Error when trying to execute SQL update player data,  ' + err);
                            return;
                        }
                        if (rowCount == 1) {
                            // 1 row updated
                            sock.write(encrypt('1'));
                        } else {
                            sock.write(encrypt('0'));
                        }
                        //release the connection back to the pool when finished
                        connection.release();
                    });
                    connection.execSql(request);
                });
            }
        });
    }
    // case 1
    function getPlayerData(sock, dataSent) { // get player data when game starts
        // dataSent will have the username
        // get all player data, parse, then send
        // acquire a db connection from connection pool
        pool.acquire(function(err, connection) {
            if (err) {
                console.error('(getPlayerData) Error when trying to acquire a DB connection from pool,  ' + err);
                return;
            }
            //use the connection as normal
            var request = new Request("select * from PlayerDataTable  where UserName = '" + dataSent + "'", function(err, rowCount) {
                if (err) {
                    sock.write(encrypt('0'));
                    console.error('(getPlayerData) Error when trying to execute SQL select * from ,  ' + err);
                    return;
                }
                if (rowCount < 1) {
                    // error retrieving user
                    sock.write(encrypt('0'));
                }
                //release the connection back to the pool when finished
                connection.release();
            });
            request.on('row', function(columns) {
                var playerData = new PlayerData();
                columns.forEach(function(column) {
                    if (column.metadata.colName === "UserName") {
                        playerData.userName = column.value;
                    } else if (column.metadata.colName === "rep") {
                        playerData.rep = column.value;
                    } else if (column.metadata.colName === "driftDistance") {
                        playerData.driftMax = column.value;
                    } else if (column.metadata.colName === "coin") {
                        playerData.coin = column.value;
                    } else if (column.metadata.colName === "ruby") {
                        playerData.ruby = column.value;
                    } else if (column.metadata.colName === "boughtProducts") {
                        playerData.boughtProducts = column.value;
                    } else if (column.metadata.colName === "equippedProducts") {
                        playerData.equipedProducts = column.value;
                    } else if (column.metadata.colName === "dailyReps") {
                        playerData.dailyRepsGiveAway = column.value;
                    }
                });

                asyncJSON.stringify(playerData, function(err, jsonValue) {
                    if (err) {
                        console.error('(getPlayerData) Error when trying to stringify json, json is ' + playerData + ', and the error is ' + err);
                    } else {
                        sock.write(encrypt(jsonValue));
                    }
                });
            });
            connection.execSql(request);
        });
    }
    // case 2
    function createUser(sock, dataSent) { // create a new username for a player
        // dataSent will have the username
        // if query succeeded print 1 else 0
        //acquire a db connection from connection pool
        pool.acquire(function(err, connection) {
            if (err) {
                console.error('(createUser) Error when trying to acquire a DB connection from pool,  ' + err);
                sock.write(encrypt('0'));
                return;
            }
            //console.error('name sent is ' + name);
            //use the connection as normal
            var request = new Request("INSERT INTO PlayerDataTable  (username,coin,ruby) VALUES ('" + dataSent + "',150,20)", function(err, rowCount) {
                if (err) {
                    console.error('(createUser) Error when trying to execute SQL INSERT INTO ,  ' + err);
                    sock.write(encrypt('0'));
                } else {
                    sock.write(encrypt('1'));
                }
                //release the connection back to the pool when finished
                connection.release();
            });
            connection.execSql(request);
        });
    }