price cuts (fix)

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script>
google.charts.load('current', {'packages':['corechart']});

document.addEventListener("DOMContentLoaded", function () {
    const CHART_WIDTH = 700, CHART_HEIGHT = 200;
    let chartContainer, chart;
    let TD_SPAN = 1;

    function buildChart() {
        // <div id="curve_chart" style="width: 900px; height: 500px"></div>
        chartContainer = document.createElement("tr");
        const td = document.createElement("td");
        td.setAttribute("colspan", TD_SPAN);
        td.setAttribute("align", "right");
        td.setAttribute("style", "position: relative;");
        chartContainer.appendChild(td);

        chart = document.createElement("div");
        chart.setAttribute("id", "curve_chart");
        chart.setAttribute("style", `width: ${CHART_WIDTH}px; height: ${CHART_HEIGHT}px`);
        td.appendChild(chart);

        const close = document.createElement("div");
        close.innerHTML = "&#10060;";
        td.appendChild(close);
        close.setAttribute("style", "position: absolute; top: 5px; right: 5px; cursor: pointer;");
        close.onclick = closeChart;
    }

    function closeChart() {
        chartContainer.parentElement.removeChild(chartContainer);
        chart = null;
    }

    let lastCutLinkClicked;
    const rows = Array.from(document.querySelectorAll("table tr"));
    if (rows.length > 0) TD_SPAN = rows[0].querySelectorAll("td").length;
    rows.forEach(function (row) {
        const cut = row.querySelector(".cutprice");
        cut.onclick = function (event) {
            if (event.target === lastCutLinkClicked) {
                closeChart();
                lastCutLinkClicked = null;
                return;
            }
            lastCutLinkClicked = event.target;

            if (!chart) buildChart();
            const tr = event.target.closest("tr");
            tr.insertAdjacentElement("afterend", chartContainer);

            const link = event.target.closest("a");
            const data = link.getAttribute("history");
            const options = {
                    currency: link.getAttribute("currency")
            }
            setTimeout(function () {
                drawChart(data, options);
            }, 1);

            event.preventDefault();
        };
    });

    function drawChart(dataToPlot, options) {
        var splitData = dataToPlot.split(";");
        var splitData = splitData.filter(function (el) {
            return el !== "";
        });

        var firstDate = new Date(toDate(splitData[0].split(',')[0]));
        var lastDate = new Date(toDate(splitData[splitData.length - 1].split(',')[0]));

        var dateDifference = daysBetween(firstDate, lastDate);

        // console.log(dateDifference);

        var datePeriodArray = [];
        datePeriodArray.push(firstDate);

        for (var i = 1; i <= dateDifference; i++) {
            let nextDate = new Date(firstDate.getFullYear(), firstDate.getMonth(), firstDate.getDate());
            nextDate.setDate(firstDate.getDate() + i);
            datePeriodArray.push(nextDate);
        }

        var DateKeyDataArray = new Object();

        splitData.forEach(function(el, index){
            var elParts = el.split(',');
            DateKeyDataArray[toDate(elParts[0])] = parseInt(elParts[1]) / 100.0;
        });

        var finalDataArray = [['Date', 'Price']];
        var lastStablePricePoint = null;

        for (var i in datePeriodArray) {

            var priceValue = DateKeyDataArray[datePeriodArray[i]];
            if(priceValue == null){
                priceValue = lastStablePricePoint;
            }

            lastStablePricePoint = priceValue;

            var dataPointArray = [datePeriodArray[i], priceValue];
            finalDataArray.push(dataPointArray);
        }

        // console.log(finalDataArray);

        var oneMonthStepprDateArray = [];
        for (var i = 1; i <= 30; i++) {
            let previousDate = new Date();
            previousDate.setDate(previousDate.getDate() - i);
            oneMonthStepprDateArray.unshift(previousDate);
        }

        function _draw(dataArray) {
            const data = google.visualization.arrayToDataTable(dataArray);
            const formatter = new google.visualization.NumberFormat({decimalSymbol: '.', groupingSymbol: ',', prefix: `${options.currency} `});
            formatter.format(data, 1);

            var chartOptions = {
                // title: `Price`,
                curveType: 'none',
                interpolateNulls: true,
                // legend: { position: 'bottom' },
                legend: 'none',
                // width: CHART_WIDTH,
                // height: CHART_HEIGHT,
                // trendlines: {
                //    0: {
                //      type: 'linear',
                //      color: 'green',
                //      lineWidth: 3,
                //      opacity: 0.3,
                //      showR2: false,
                //      visibleInLegend: false
                //    }
                //  },
                /* explorer: {
                    keepInBounds: true,
                    axis: "horizontal",
                }, */
                "chartArea": {
                    "width": "85%",
                    "height": "85%"
                },
                hAxis: {
                //     ticks: oneMonthStepprDateArray,

                    gridlines: {
                        // opacity: 0,
                        color: "white",
                        // count: 0,
                    },
                    format: "yyyy-MM-dd",
                    textStyle: {
                        fontSize : 9,
                    },
                },
                vAxis: {
                    // format: "currency",
                    textStyle: {
                        fontSize : 11,
                    },
                },
            };

            (new google.visualization.LineChart(chart)).draw(data, chartOptions);
        }

        function treatAsUTC(date) {
            var result = new Date(date);
            result.setMinutes(result.getMinutes() - result.getTimezoneOffset());
            return result;
        }

        function daysBetween(startDate, endDate) {
            var millisecondsPerDay = 24 * 60 * 60 * 1000;
            return (treatAsUTC(endDate) - treatAsUTC(startDate)) / millisecondsPerDay;
        }

        function toDate(dateStr) {
            var parts = dateStr.split("-");
            return new Date(parseInt(parts[0]), parseInt(parts[1] - 1), parseInt(parts[2]));
        }

        _draw(finalDataArray);
    }
});
</script>