Some very tricky bot

bot.js

window.bot = (function() {
    var intervalId = null;
    function start(baseBet) {
        if (!baseBet) throw Error('Usage: bot.start(baseBet)');
        var state = null;
        var nextBetSum = baseBet;
        var betIsMade = false;
        intervalId = setInterval(function() {
            var bannerText = $('#banner').text();
            var balance = Number($('#balance').text());
            var balanceDiff = $('#panel1-7 .mytotal').text();
            
            if (bannerText.match(/^Rolling/) && state !== 'rolling') {
                state = 'rolling';
                if (!betIsMade) {
                    makeBet(nextBetSum);
                    betIsMade = true;
                }   
            } else if (balanceDiff.match(/^[-+]/) && state !== 'rolled') {
                state = 'rolled';
                betIsMade = false;
                
                var balnaceDiffNum = Number(balanceDiff);
                if (balnaceDiffNum > 0) {
                    nextBetSum = baseBet;
                } else if (balnaceDiffNum < 0) {
                    nextBetSum *= 2;
                } else {
                    console.log('Cant be!');
                }   
            }   
        }, 300);
    
        function makeBet(sum) {
            $('#betAmount').val(sum);
            $('.betButton[data-lower="1"]').click();
        }  
    }   

    function stop() {
        clearInterval(intervalId);
        intervalId = null;
    } 
    
    return {start: start, stop: stop};
})();