var express = require('express');
var router = express.Router();

var myDB = require('../db-connection');

function generateSession() {
    var session_id = '';
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for (var i = 0; i < 30; i++) session_id += possible.charAt(Math.floor(Math.random() * possible.length));

    return session_id;
}

router.get('/generateSession', function(req, res){
    var session_id = '';
    var id_is_valid = false;
    while (!id_is_valid){
        session_id = generateSession();

        myDB.query("SELECT * FROM activeUser WHERE session_id = ?", [session_id], function(error, results, field){
            if(error) throw error;
            else{
                if (results.length === 0) is_is_valid = true;
            }
        });
    }

    myDB.query("INSERT INTO activeUser (is_registered, session_id) VALUES (0, ?)", [session_id], function(error, results, fields){
        if (error) res.send('{"success": false}');
        else res.send('{"success": true, "session_id": "' + session_id + '"}');
    });
});