let chart_instance = null;

Chart.defaults.global.defaultFontFamily = "'Varela Round', sans-serif";

const chart_options = {
  elements: {
    line: {
      backgroundColor: "#DEF2D9",
      backgroundColor: "#DEF2D9",
      cubicInterpolationMode: "monotone",
    },
  },
  maintainAspectRatio: false,
  tooltips: {
    intersect: false,
    mode: "index",
  },
};

function update_chart(input_data, possibilities) {
  var ctx = $("#chart");

  datasets = [
    {
      label: i18next.t("output.chart.input"),
      data: input_data.slice(1),
      fill: false,
    },
    {
      label: i18next.t("output.chart.minimum"),
      data: possibilities[0].prices.slice(1).map(day => day.min),
      fill: false,
    },
    {
      label: i18next.t("output.chart.maximum"),
      data: possibilities[0].prices.slice(1).map(day => day.max),
      fill: "-1",
    },
  ];

  if (chart_instance) {
    chart_instance.data.datasets = datasets;
    chart_instance.update();
  } else {
    chart_instance = new Chart(ctx, {
      data: {
        datasets: datasets,
        labels: [i18next.t("weekdays.sunday"), i18next.t("weekdays.abr.monday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.monday") + " " + i18next.t("times.afternoon"), i18next.t("weekdays.abr.tuesday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.tuesday") + " " + i18next.t("times.afternoon"), i18next.t("weekdays.abr.wednesday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.wednesday") + " " + i18next.t("times.afternoon"), i18next.t("weekdays.abr.thursday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.thursday") + " " + i18next.t("times.afternoon"), i18next.t("weekdays.abr.friday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.friday") + " " + i18next.t("times.afternoon"), i18next.t("weekdays.abr.saturday") + " " + i18next.t("times.morning"), i18next.t("weekdays.abr.saturday") + " " + i18next.t("times.afternoon")],
      },
      options: chart_options,
      type: "line",
    });
  }
}