Column with Drilldown in JavaScript

// Shared overrides for every drilled-down level: the root is a single-series
// chart, but each drill reveals a 3-series (Online / Retail / Wholesale)
// grouped column breakdown — so drilling explores more data beneath.
var childPlot = {
  bar: {
    horizontal: false,
    distributed: false,
    columnWidth: '70%',
    borderRadius: 3,
    borderRadiusApplication: 'end',
  },
}
var childLegend = { show: true, position: 'top' }

// Each year column is tinted with the base hue of its drilldown palette, so the
// drilled breakdown reads as "shades of that year's colour".
var yearColors = ['#1565C0', '#2E7D32', '#EF6C00', '#6A1B9A']
var bluePalette = ['#1565C0', '#42A5F5', '#90CAF9'] // 2021
var greenPalette = ['#2E7D32', '#66BB6A', '#A5D6A7'] // 2022
var amberPalette = ['#EF6C00', '#FB8C00', '#FFB74D'] // 2023
var purplePalette = ['#6A1B9A', '#AB47BC', '#CE93D8'] // 2024

var options = {
  series: [
    {
      name: 'Total Sales',
      data: [
        { x: '2021', y: 480, drilldown: '2021' },
        { x: '2022', y: 530, drilldown: '2022' },
        { x: '2023', y: 610, drilldown: '2023' },
        { x: '2024', y: 705, drilldown: '2024' },
      ],
    },
  ],
  chart: {
    type: 'bar',
    height: 420,
    toolbar: {
      show: false,
    },
  },
  colors: yearColors,
  plotOptions: {
    bar: {
      horizontal: false,
      columnWidth: '55%',
      borderRadius: 6,
      borderRadiusApplication: 'end',
      distributed: true,
    },
  },
  legend: {
    show: false,
  },
  dataLabels: {
    enabled: false,
  },
  title: {
    text: 'Annual Sales by Channel',
    align: 'left',
  },
  subtitle: {
    text: 'Click a year to drill into its channel breakdown (Online / Retail / Wholesale). Use the breadcrumb to go back.',
    align: 'left',
  },
  yaxis: {
    title: {
      text: 'Sales ($k)',
    },
  },
  drilldown: {
    enabled: true,
    breadcrumb: {
      show: true,
      position: 'top-right',
      rootLabel: 'All Years',
      separator: ' / ',
    },
    series: [
      {
        id: '2021',
        name: '2021 by Channel',
        plotOptions: childPlot,
        legend: childLegend,
        colors: bluePalette,
        series: [
          {
            name: 'Online',
            data: [
              { x: 'Q1', y: 50 },
              { x: 'Q2', y: 55 },
              { x: 'Q3', y: 55 },
              { x: 'Q4', y: 60 },
            ],
          },
          {
            name: 'Retail',
            data: [
              { x: 'Q1', y: 35 },
              { x: 'Q2', y: 38 },
              { x: 'Q3', y: 40 },
              { x: 'Q4', y: 42 },
            ],
          },
          {
            name: 'Wholesale',
            data: [
              { x: 'Q1', y: 22 },
              { x: 'Q2', y: 25 },
              { x: 'Q3', y: 28 },
              { x: 'Q4', y: 30 },
            ],
          },
        ],
      },
      {
        id: '2022',
        name: '2022 by Channel',
        plotOptions: childPlot,
        legend: childLegend,
        colors: greenPalette,
        series: [
          {
            name: 'Online',
            data: [
              { x: 'Q1', y: 55 },
              { x: 'Q2', y: 60 },
              { x: 'Q3', y: 62 },
              { x: 'Q4', y: 68 },
            ],
          },
          {
            name: 'Retail',
            data: [
              { x: 'Q1', y: 40 },
              { x: 'Q2', y: 42 },
              { x: 'Q3', y: 43 },
              { x: 'Q4', y: 45 },
            ],
          },
          {
            name: 'Wholesale',
            data: [
              { x: 'Q1', y: 26 },
              { x: 'Q2', y: 28 },
              { x: 'Q3', y: 30 },
              { x: 'Q4', y: 31 },
            ],
          },
        ],
      },
      {
        id: '2023',
        name: '2023 by Channel',
        plotOptions: childPlot,
        legend: childLegend,
        colors: amberPalette,
        series: [
          {
            name: 'Online',
            data: [
              { x: 'Q1', y: 62 },
              { x: 'Q2', y: 68 },
              { x: 'Q3', y: 72 },
              { x: 'Q4', y: 78 },
            ],
          },
          {
            name: 'Retail',
            data: [
              { x: 'Q1', y: 45 },
              { x: 'Q2', y: 48 },
              { x: 'Q3', y: 50 },
              { x: 'Q4', y: 52 },
            ],
          },
          {
            name: 'Wholesale',
            data: [
              { x: 'Q1', y: 32 },
              { x: 'Q2', y: 33 },
              { x: 'Q3', y: 35 },
              { x: 'Q4', y: 35 },
            ],
          },
        ],
      },
      {
        id: '2024',
        name: '2024 by Channel',
        plotOptions: childPlot,
        legend: childLegend,
        colors: purplePalette,
        series: [
          {
            name: 'Online',
            data: [
              { x: 'Q1', y: 72 },
              { x: 'Q2', y: 78 },
              { x: 'Q3', y: 82 },
              { x: 'Q4', y: 88 },
            ],
          },
          {
            name: 'Retail',
            data: [
              { x: 'Q1', y: 52 },
              { x: 'Q2', y: 55 },
              { x: 'Q3', y: 56 },
              { x: 'Q4', y: 57 },
            ],
          },
          {
            name: 'Wholesale',
            data: [
              { x: 'Q1', y: 40 },
              { x: 'Q2', y: 41 },
              { x: 'Q3', y: 42 },
              { x: 'Q4', y: 42 },
            ],
          },
        ],
      },
    ],
  },
}

var chart = new ApexCharts(document.querySelector('#chart'), options)
chart.render()