import { useLayoutEffect, useRef, useState, type ComponentProps } from "react"
import { cn } from "cn"
import { Label, LabelList, PolarAngleAxis, PolarGrid, PolarRadiusAxis, RadialBar, RadialBarChart } from "recharts"
import { ChartContainer, ChartTooltip, ChartTooltipContent } from "./chart"
import { CenterText, type HMDonutDatum } from "./donut-chart"
import { seriesColor, seriesToConfig, type ChartSeries } from "./series"
import { fitText } from "./text-fit"

// Radial charts follow the official shadcn/ui examples (chart-radial-simple, -label, -grid, -text, -shape, -stacked): the same
// angle ranges, radii, background tracks, corner rounding, grid and center text. Radii are pixels, as in the official source.
// Adjustments for HM: values come from `value`/`id` rows with HM series colors; the angle axis domain is explicit (0 to the largest
// value or stack total, the same range Recharts picks automatically) so an all-zero data set cannot produce NaN; names and center
// text are shortened to fit.

// Bar thickness is 1.5 times the earlier one (2026-11-06) in every radial chart. Recharts draws a bar over 80% of its band (10%
// margin each side), so a single bar band 1.5 times as wide gives a 1.5 times thicker bar (text, shape, stacked: the outer radius
// stays and the inner one moves in).
// Ring charts with several bars (simple, label, grid) set the bar thickness (`barSize`) and the gap between rings directly: 18px
// bars and 4px gaps (grid 16.5 and 3, the earlier gaps), and keep the earlier center hole (inner band radius 30), so the outer
// radius grows to inner + bars x (bar + gap): 140 for five simple / label bars, 127.5 for five grid bars (2026-11-06, the outer
// radius and chart height limits were lifted for this). Where the box is too narrow (320px screens) the three charts shrink all
// radii, bar thickness and gaps in proportion (`useFitScale`).
// The legend is drawn under the chart box, not inside it: the chart box is a fixed height that holds the largest ring, however
// many lines the legend wraps to.
const RADIAN = Math.PI / 180
/** Height of the chart box of every radial chart (px): the largest ring (outer radius 140) plus the 5px chart margins. */
const CHART_BOX = "aspect-auto h-[300px] w-full"
const EDGE = 6 // px kept free on both sides of a ring (chart margin 5 + 1)
const MIN_SCALE = 0.5
const LABEL_SIZE = 11
const MIN_LABEL_CHARS = 2

type PolarSector = { cx: number; cy: number; innerRadius: number; outerRadius: number; startAngle: number; endAngle: number }

/** Name inside the start of its bar, curved along the arc like the official "insideStart" label, shortened to the bar length. */
function RadialNameLabel({ viewBox, value }: { viewBox?: unknown; value?: unknown }) {
  const sector = viewBox as Partial<PolarSector> | undefined
  if (!sector || sector.innerRadius === undefined || sector.outerRadius === undefined || sector.startAngle === undefined || sector.endAngle === undefined) return null
  const radius = (sector.innerRadius + sector.outerRadius) / 2
  const arcLength = radius * Math.abs(sector.endAngle - sector.startAngle) * RADIAN
  const text = fitText(String(value ?? ""), arcLength - 14, LABEL_SIZE)
  if ([...text].length < MIN_LABEL_CHARS) return null
  return <Label viewBox={viewBox as ComponentProps<typeof Label>["viewBox"]} position="insideStart" value={text} className="hm-radial-name" />
}

/** Legend under the chart box, built from the series (same look as the shadcn legend; it needs no Recharts context). */
function RadialLegend({ series }: { series: readonly ChartSeries[] }) {
  return (
    <div data-slot="chart-legend-content" className="flex flex-wrap items-center justify-center gap-x-4 gap-y-1 pt-3 text-xs">
      {series.map((item, index) => (
        <div key={item.key} className="flex items-center gap-1.5">
          <div className="h-2 w-2 shrink-0 rounded-[2px]" style={{ backgroundColor: seriesColor(index, item.color) }} />
          {item.label}
        </div>
      ))}
    </div>
  )
}

/** Scale (at most 1) that makes a ring of `radius` px fit the width of the element behind `ref`; measured, so it follows the layout. */
function useFitScale(radius: number) {
  const ref = useRef<HTMLDivElement | null>(null)
  const [scale, setScale] = useState(1)
  useLayoutEffect(() => {
    const node = ref.current
    if (!node) return
    const update = () => {
      const width = node.getBoundingClientRect().width
      if (width > 0) setScale(Math.min(1, Math.max(MIN_SCALE, Math.floor(((width / 2 - EDGE) / radius) * 100) / 100)))
    }
    update()
    const observer = new ResizeObserver(update)
    observer.observe(node)
    return () => observer.disconnect()
  }, [radius])
  return [ref, scale] as const
}

const px = (value: number) => Math.round(value * 10) / 10

function maxOf(values: readonly number[]) {
  const max = Math.max(0, ...values.filter(Number.isFinite))
  return max > 0 ? max : 1
}

export type HMRadialBarChartProps = {
  data: readonly HMDonutDatum[]
  /** Official `chart-radial-label`: item names inside the start of each bar. */
  labels?: boolean
  /** Official `chart-radial-grid`: circular grid lines, no background track. */
  grid?: boolean
  /** Background track behind each bar (default on, off with `grid`). */
  background?: boolean
  /** Arc range in degrees. Official: simple/grid 0 to 360, label -90 to 380. */
  startAngle?: number
  endAngle?: number
  /** Pixel radius of the innermost bar band (the center hole). Default 30, as before the thickness change. */
  innerRadius?: number
  /** Pixel radius of the outermost bar band. Default: `innerRadius` + one `barSize + ringGap` per item (five items: 140, grid 127.5). */
  outerRadius?: number
  /** Bar thickness in px. Defaults: 18 (grid 16.5), 1.5 times the earlier 12 (grid 11). */
  barSize?: number
  /** Gap between neighboring bars in px. Defaults: 4 (grid 3), the same as before the thickness change. */
  ringGap?: number
  /** Accessible name of the chart. */
  label: string
  className?: string
}

/** Radial bar chart with one bar per item (official simple, label and grid examples). */
export function HMRadialBarChart({
  data,
  labels = false,
  grid = false,
  background,
  startAngle,
  endAngle,
  innerRadius = 30,
  outerRadius,
  barSize = grid ? 16.5 : 18,
  ringGap = grid ? 3 : 4,
  label,
  className,
}: HMRadialBarChartProps) {
  const rows = data.map(item => ({ ...item, fill: `var(--color-${item.id})` }))
  const series = data.map(item => ({ key: item.id, label: item.label, color: item.color }))
  const config = seriesToConfig(series)
  const outer = outerRadius ?? innerRadius + Math.max(data.length, 1) * (barSize + ringGap)
  const [fitRef, scale] = useFitScale(outer)
  return (
    <div ref={fitRef} data-slot="chart-radial" className="flex w-full flex-col">
      <ChartContainer config={config} role="group" aria-label={label} className={cn(CHART_BOX, className)}>
        <RadialBarChart
          accessibilityLayer
          data={rows}
          startAngle={startAngle}
          endAngle={endAngle}
          innerRadius={px(innerRadius * scale)}
          outerRadius={px(outer * scale)}
        >
          <ChartTooltip cursor={false} content={<ChartTooltipContent hideLabel nameKey="id" />} />
          {grid ? <PolarGrid gridType="circle" /> : null}
          <PolarAngleAxis type="number" domain={[0, maxOf(data.map(item => item.value))]} tick={false} axisLine={false} />
          <RadialBar dataKey="value" background={background ?? !grid} barSize={px(barSize * scale)}>
            {labels ? <LabelList dataKey="label" content={<RadialNameLabel />} /> : null}
          </RadialBar>
        </RadialBarChart>
      </ChartContainer>
      <RadialLegend series={series} />
    </div>
  )
}

export type HMRadialMeterChartProps = {
  /** The single value; `label` is the center caption's fallback. */
  item: HMDonutDatum
  /** Caption under the value in the center. Defaults to the item's name. */
  caption?: string
  /** Arc range in degrees. Official text: 0 to 250, shape: 0 to 100. */
  startAngle?: number
  endAngle?: number
  /** Pixel radii of the bar band. Text: 75 and 90, shape: 50 and 95 (official 80 / 90 and 65 / 95 were 1.5 times thinner). */
  innerRadius?: number
  outerRadius?: number
  /**
   * Pixel radii of the two filled circles that form the ring track behind the bar (official `polarRadius`), the outer one first.
   * The track is as thick as the bar and lines up with it: the bar fills 80% of its band, so the radii sit 10% of the band inside
   * it. Text: [88.5, 76.5], shape: [90.5, 54.5].
   */
  trackRadii?: readonly [number, number]
  /** Corner rounding of the bar in px (official text: 10). */
  cornerRadius?: number
  /** Accessible name of the chart. */
  label: string
  className?: string
}

/** Single-value radial chart with the value and caption in the center (official text and shape examples). */
export function HMRadialMeterChart({
  item,
  caption,
  startAngle = 0,
  endAngle = 250,
  innerRadius = 75,
  outerRadius = 90,
  trackRadii = [88.5, 76.5],
  cornerRadius,
  label,
  className,
}: HMRadialMeterChartProps) {
  const row = { ...item, fill: `var(--color-${item.id})` }
  const config = seriesToConfig([{ key: item.id, label: item.label, color: item.color }])
  return (
    <ChartContainer config={config} role="group" aria-label={label} className={cn(CHART_BOX, className)}>
      <RadialBarChart data={[row]} startAngle={startAngle} endAngle={endAngle} innerRadius={innerRadius} outerRadius={outerRadius}>
        {/* Official: the first circle is the track (official muted, HM --hm-chart-track), the second (smaller) one is the chart surface color that cuts it into a ring. */}
        <PolarGrid
          gridType="circle"
          radialLines={false}
          stroke="none"
          className="first:fill-[var(--hm-chart-track)] last:fill-[var(--hm-chart-surface)]"
          polarRadius={[...trackRadii]}
        />
        <PolarAngleAxis type="number" domain={[0, maxOf([item.value])]} tick={false} axisLine={false} />
        <RadialBar dataKey="value" background cornerRadius={cornerRadius} />
        <PolarRadiusAxis tick={false} tickLine={false} axisLine={false}>
          <Label
            content={({ viewBox }) => {
              if (!viewBox || !("cx" in viewBox) || !("cy" in viewBox)) return null
              return (
                <CenterText
                  cx={Number(viewBox.cx)}
                  cy={Number(viewBox.cy)}
                  innerRadius={Math.min(trackRadii[1], innerRadius)}
                  value={item.value}
                  caption={caption ?? item.label}
                  maxSize={36}
                />
              )
            }}
          />
        </PolarRadiusAxis>
      </RadialBarChart>
    </ChartContainer>
  )
}

export type HMRadialStackedChartProps = {
  /** Stacked from the first series outwards along the arc. Official order: mobile (570) first, then desktop (1260). */
  series: readonly ChartSeries[]
  /** One value per series key. */
  row: Readonly<Record<string, number>>
  /** Caption under the total in the center. */
  totalLabel: string
  /** Arc range in degrees. Official: 0 to 180 (half circle). */
  startAngle?: number
  endAngle?: number
  innerRadius?: number
  outerRadius?: number
  /** Accessible name of the chart. */
  label: string
  className?: string
}

/** Stacked radial chart: one row, each series a segment of the same arc, total in the center (official `chart-radial-stacked`). */
export function HMRadialStackedChart({
  series,
  row,
  totalLabel,
  startAngle = 0,
  endAngle = 180,
  innerRadius = 65,
  outerRadius = 110,
  label,
  className,
}: HMRadialStackedChartProps) {
  const total = series.reduce((sum, item) => sum + (Number(row[item.key]) || 0), 0)
  return (
    <div data-slot="chart-radial" className="flex w-full flex-col">
      <ChartContainer config={seriesToConfig(series)} role="group" aria-label={label} className={cn(CHART_BOX, className)}>
        {/* The official chart sits at the middle of its square box; the half circle (outer radius 110) is moved down so it is centered in the 300px box. */}
        <RadialBarChart accessibilityLayer data={[row]} cy="68%" startAngle={startAngle} endAngle={endAngle} innerRadius={innerRadius} outerRadius={outerRadius}>
          <ChartTooltip cursor={false} content={<ChartTooltipContent hideLabel />} />
          <PolarAngleAxis type="number" domain={[0, total > 0 ? total : 1]} tick={false} axisLine={false} />
          {series.map(item => (
            <RadialBar
              key={item.key}
              dataKey={item.key}
              stackId="a"
              fill={`var(--color-${item.key})`}
              cornerRadius={5}
              stroke="var(--hm-chart-surface)"
              strokeWidth={2}
            />
          ))}
          <PolarRadiusAxis tick={false} tickLine={false} axisLine={false}>
            <Label
              content={({ viewBox }) => {
                if (!viewBox || !("cx" in viewBox) || !("cy" in viewBox)) return null
                return <CenterText cx={Number(viewBox.cx)} cy={Number(viewBox.cy)} innerRadius={innerRadius} value={total} caption={totalLabel} dy={-14} />
              }}
            />
          </PolarRadiusAxis>
        </RadialBarChart>
      </ChartContainer>
      <RadialLegend series={series} />
    </div>
  )
}