(function() {
    'use strict';

    var time = function() {
        return moment().format('h:mm:ss a');
    };

    function updateChart() {
        d3.select('#current-seconds')
            .append('li')
            .style('width', function() { return _.random(300, 800) + 'px'; })
            .html('<i class="fa fa-bar-chart"></i> chart updated: ' + time());
    } 


    // have a reference of the current seconds
    console.log('current time in seconds');
    console.log(moment().format('ss'));

    // update chart every minute (from random start) 
    // base source: http://stackoverflow.com/a/14644729/1711570
    function setChartInterval() {
        // have a reference of the current seconds
        var currentDateSeconds = moment().format('ss');
        console.log('current time in seconds: ' + '\n' + currentDateSeconds);
        // PASS if initial page load is within the second half of minute
        if (currentDateSeconds > 30 && currentDateSeconds <= 55) {
            // update chart every 60 seconds
            setInterval(updateChart, 60000);

            console.log('PASSED: so refresh every 60 seconds');
            console.log(moment().format('h:mm:ss a'));

        }
        else {
            setTimeout(function () {
                setChartInterval();
            }, ((_.random(30, 40)) - currentDateSeconds) * 1000);

            console.log('FAIL: so set setTimeout (with some randomness)');
            console.log(moment().format('h:mm:ss a'));
        }
        
    }

    updateChart();
    setChartInterval();


})();