$(function () {
    xmlhttp = new XMLHttpRequest()

    xmlhttp.open("GET", "mysql.php?p=getfullstats", true);
    xmlhttp.send();

    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            var jsontext = xmlhttp.responseText;
            var json = JSON.parse(jsontext);


            if (jsontext == '[]') {
                return false
            } else {

                var newTr = '';


                for (var i = 0; i < json.length; i++) {
                    newTr += (' / ' + json[i].date + ' ' + json[i].price);



                    // parse a date in dd-mm-yyyy
                    function parseDate(input) {
                        var parts = input.match(/(\d+)/g);
                        // new Date(year, month [, date [, hours[, minutes[, seconds[, ms]]]]])
                        return new Date(parts[2], parts[1] - 1, parts[0]); // months are 0-based
                    }



                    // get sum of prices for given month
                    function getSumForMonth(data, month) {
                        var sum = 0;
                        month -= 1; // months are 0-based 
                        $.each(data, function (idx, item) {
                            if (parseDate(item.date).getMonth() == month) {
                                sum += parseFloat(item.price);
                            }
                        });
                        return sum;
                    }


                    var sum = getSumForMonth(json, 9); // sum for september
                    console.log(sum);

                }
            }
        }
    }

});