import { ScaleBand } from "d3-scale";

import { ExtendedGroupItem } from "../components/Bars/Bars";
import { EGroupedBarLayout, HistogramBar } from "../Histogram";

export type GroupedProps = {
  groupLayout: EGroupedBarLayout;
  stacked?: boolean;
};

export const groupedBarsUseSameXAxisValue = ({
  groupLayout,
  stacked,
}: GroupedProps): boolean => {
  return (
    stacked ||
    groupLayout === EGroupedBarLayout.STACKED ||
    groupLayout === EGroupedBarLayout.OVERLAID
  );
};

/**
 *This is the inner padding between each grouped dataset or single datasets.
 */
export const paddingInner = (bar: HistogramBar): number => {
  const m = bar?.paddingInner ?? 0;
  return m >= 0 && m <= 1 ? m : 0.1;
};

/**
 * Padding for the outside of grouped datasets or single datasets
 *
 */
export const paddingOuter = (bar: HistogramBar): number => {
  const m = bar?.paddingOuter ?? 0;
  return m >= 0 && m <= 1 ? m : 0.1;
};

/**
 * Get the bar width
 * Uses the (grouped)inner/outer padding bar properties.
 * if layout = OVERLAID then offset by the overlayMargin.
 * If the overlayMargin < 1 then use it as a percentage offset of the bar width
 * If its >= 1 then use as a pixel offset
 * @return number min of 1
 */
export const getBarWidth = (
  i: number,
  groupLayout: EGroupedBarLayout,
  bar: HistogramBar,
  innerScaleBand: ScaleBand<string>,
) => {
  const w = innerScaleBand.bandwidth();
  let overlay =
    groupLayout !== EGroupedBarLayout.OVERLAID
      ? 0
      : bar.overlayMargin >= 1
      ? i * bar.overlayMargin * 2
      : Math.round(i * bar.overlayMargin * w);

  if (groupLayout === EGroupedBarLayout.OVERLAID && overlay === 1 && w > 4) {
    overlay = 2;
  }
  return Math.max(1, w - overlay);
};

/**
 * When grouping data this is the spacing between the group's bars.
 */
export const groupedPaddingInner = (bar: HistogramBar): number => {
  const m = bar?.grouped?.paddingInner ?? 0.1;
  return m >= 0 && m <= 1 ? m : 0.1;
};

/**
 * When grouping data this is the spacing to the left of the first and the right of the last bar.
 */
export const groupedPaddingOuter = (bar: HistogramBar): number => {
  const m = bar?.grouped?.paddingOuter ?? 0.1;
  return m >= 0 && m <= 1 ? m : 0.1;
};

export const buildBarDatasets = ({ values, bins, visible }) => {
  const dataSets: ExtendedGroupItem[] = [];

  const binLabels = bins.reduce(
    (p, n) => p.concat(Array.isArray(n) ? n : [n]),
    [] as (number | string)[],
  );

  values.forEach((count, datasetIndex) => {
    const total = count.data.reduce((p, n) => p + n, 0);
    count.data.forEach((value, i) => {
      dataSets.push({
        groupLabel: count.label,
        datasetIndex,
        label: String(binLabels[i]),
        binIndex: i,
        percentage: total === 0 ? "0" : ((value / total) * 100).toFixed(2),
        value:
          visible[binLabels[i]] !== false && visible[count.label] !== false
            ? value
            : 0,
      });
    });
  });
  return { binLabels, dataSets };
};