Count down timer in seconds

bw-timer.js

function BWTimer(_delay, _step) {

    var self = this;
    
    /**
     * Delay in seconds
     */
    var delay = _delay;
    
    /**
     * Delay in seconds
     */
    var step = _step;
    
    /**
     * Timeout in seconds
     */
    var timeout = _step * 1000;
    
    
    this.setDelay = function(_delay) {
        delay = _delay;
        return this;
    }
    
    this.getDelay = function() {
        return delay;
    }
    
    this.setStep = function(_step) {
        step = _step;
        timeout = step * 1000;
        return this;
    }
    
    this.getStep = function() {
        return step;
    }
    
    /**
     * Count down
     */
    this.countDown = function(stepCallback, endCallback) {
        if (typeof stepCallback === 'function') {
            stepCallback(delay);
        } else {
            console.log(delay);
        }
        
        setTimeout(function(){
            delay -= step;
            
            if (delay > 0) {
                return self.countDown(stepCallback, endCallback);
            }
            
            if (typeof stepCallback === 'function') {
                stepCallback(delay);
            } else {
                console.log(delay);
            }
            
            if (typeof endCallback === 'function') {
                return endCallback();
            } else {
                alert('Time out!');
            }
        }, timeout);
    }
    
    return this;
}

var timer = new BWTimer(5, 1);
timer.countDown(
    function(delay){
        console.log(delay);
    },
    function(){
        alert("It's over!");
    }
);