import { useState } from 'react';
import {
  Bar,
  BarChart,
  CartesianGrid,
  Cell,
  ComposedChart,
  Line,
  ReferenceLine,
  ResponsiveContainer,
  Tooltip,
  XAxis,
  YAxis,
} from 'recharts';
import { Table2 } from 'lucide-react';
import type { BriefingData, Slice } from '../api/charts';
import { RECOVERY_ORDER } from '../api/charts';
import { useTheme } from '../theme';
import { money, moneyShort, shortDate } from '../format';

/**
 * The briefing charts — four pictures that carry the case.
 *
 * FORM FIRST, COLOUR LAST (the dataviz method):
 *   1. The spike        — one line, the flagged slice's weekly denials, with the
 *                         bulletin date drawn as a reference line. EMPHASIS form:
 *                         weeks after the spike in the accent hue, before in gray.
 *   2. Where it sits    — payer denial rate, baseline vs recent, grouped bar.
 *                         Two series: gray = before, accent = now.
 *   3. The money        — the flagged slice's denied claims by what can still
 *                         happen to them. Stacked horizontal bar, one row.
 *   4. Expiring         — unfiled appeals closing within 14 days, by payer.
 *                         Single hue, sorted; the axis carries identity.
 *
 * COLOURS are the validated reference slots (blue 1, orange 2, green 6, red 8)
 * stepped per theme — run through scripts/validate_palette.js on THIS console's
 * surfaces (#ffffff / #10233a): all checks pass. The brand teal deliberately is
 * NOT used as a data hue — it fails the chroma floor and would read as gray on
 * a chart. Gray is the de-emphasis hue of the emphasis form, never a series.
 *
 * Every chart has a table twin (the ⊞ toggle) so no value lives only in colour
 * or only in a tooltip.
 */

const HUES = {
  light: { accent: '#2a78d6', gray: '#94a3af', good: '#008300', warn: '#eb6834', bad: '#e34948', violet: '#4a3aa7', ink: '#0f2233', muted: '#5a7089', grid: '#e3eef1', ai: '#5b2ca0' },
  dark: { accent: '#3987e5', gray: '#6f8595', good: '#22a422', warn: '#d95926', bad: '#e66767', violet: '#9085e9', ink: '#e7f1f5', muted: '#93b2c0', grid: '#22405c', ai: '#c9b3f2' },
};

const RECOVERY_HUE: Record<string, keyof typeof HUES.light> = {
  recovered: 'good',
  'appeal filed': 'accent',
  'still appealable': 'warn',
  // Violet, not red: red sits beside orange in the stack and the two fail the
  // adjacent-pair check under deutan and even normal vision (ΔE 7.1).
  'lost on appeal': 'violet',
  'window closed': 'gray',
};

export function Briefing({ data, slice }: { data: BriefingData; slice: Slice | null }) {
  const { theme } = useTheme();
  const c = HUES[theme];
  const title = slice ? [slice.payer, slice.department, slice.code].filter(Boolean).join(' · ') : 'the hospital';

  return (
    <section className="space-y-3">
      <div className="grid gap-3 lg:grid-cols-2">
        <SpikeChart data={data} slice={slice} c={c} title={title} />
        <PayerChart data={data} slice={slice} c={c} />
        {data.recovery.length > 0 && <RecoveryChart data={data} c={c} title={title} />}
        {data.expiring.length > 0 && <ExpiringChart data={data} c={c} />}
      </div>
    </section>
  );
}

// ---------------------------------------------------------------------------

function Frame({
  title,
  caption,
  table,
  children,
}: {
  title: string;
  caption: string;
  table: { head: string[]; rows: (string | number)[][] };
  children: React.ReactNode;
}) {
  const [showTable, setShowTable] = useState(false);
  return (
    <figure className="lift rounded-xl border border-line bg-panel px-4 pt-3.5 pb-2">
      <figcaption className="flex items-start gap-2">
        <span className="min-w-0 flex-1">
          <span className="block text-sm font-semibold text-ink">{title}</span>
          <span className="block text-xs text-muted">{caption}</span>
        </span>
        <button
          onClick={() => setShowTable(!showTable)}
          title={showTable ? 'Show chart' : 'Show as table'}
          aria-label={showTable ? 'Show chart' : 'Show as table'}
          className="rounded p-1 text-faint hover:bg-panel2 hover:text-ink"
        >
          <Table2 className="h-3.5 w-3.5" />
        </button>
      </figcaption>
      <div className="mt-2 h-[220px]">
        {showTable ? (
          <div className="h-full overflow-auto">
            <table className="w-full text-xs">
              <thead>
                <tr>
                  {table.head.map((h) => (
                    <th key={h} className="border-b border-line px-2 py-1 text-left font-semibold text-faint">
                      {h}
                    </th>
                  ))}
                </tr>
              </thead>
              <tbody>
                {table.rows.map((r, i) => (
                  <tr key={i}>
                    {r.map((v, j) => (
                      <td key={j} className={`tnum border-b border-line px-2 py-1 ${j ? 'text-right' : ''} text-ink`}>
                        {v}
                      </td>
                    ))}
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        ) : (
          children
        )}
      </div>
    </figure>
  );
}

const tip = (c: typeof HUES.light) => ({
  contentStyle: { background: 'var(--color-panel)', border: '1px solid var(--color-line)', borderRadius: 8, fontSize: 12, color: c.ink },
  labelStyle: { color: c.muted, fontWeight: 600 },
  itemStyle: { color: c.ink },
  cursor: { stroke: c.grid },
});

const axis = (c: typeof HUES.light) => ({ tick: { fill: c.muted, fontSize: 11 }, axisLine: { stroke: c.grid }, tickLine: false as const });

// 1. The spike ----------------------------------------------------------------
function SpikeChart({ data, slice, c, title }: { data: BriefingData; slice: Slice | null; c: typeof HUES.light; title: string }) {
  const pts = data.weeklySlice.length ? data.weeklySlice : data.weeklyRate;
  const isSlice = data.weeklySlice.length > 0;
  const spike = slice?.spikeStart ?? null;
  const rows = pts.map((p) => ({ ...p, label: shortDate(p.week) }));
  return (
    <Frame
      title={isSlice ? `Denied claims per week — ${title}` : 'Hospital denial rate per week'}
      caption={spike ? `Vertical line: the payer's rule change, ${shortDate(spike)}. Bars after it are the spike.` : 'Six months, one point per week'}
      table={{ head: ['Week', isSlice ? 'Denied' : 'Denial %'], rows: rows.map((r) => [r.label, isSlice ? r.denied : `${r.pct}%`]) }}
    >
      <ResponsiveContainer width="100%" height="100%">
        <ComposedChart data={rows} margin={{ top: 8, right: 8, bottom: 0, left: -18 }}>
          <CartesianGrid vertical={false} stroke={c.grid} />
          <XAxis dataKey="label" {...axis(c)} interval="preserveStartEnd" minTickGap={28} />
          <YAxis {...axis(c)} width={44} tickFormatter={(v) => (isSlice ? String(v) : `${v}%`)} />
          <Tooltip {...tip(c)} formatter={(v: unknown) => (isSlice ? [`${Number(v)} denied`, ''] : [`${Number(v)}%`, 'denial rate'])} />
          {isSlice ? (
            <Bar dataKey="denied" radius={[4, 4, 0, 0]} maxBarSize={18}>
              {rows.map((r) => (
                <Cell key={r.week} fill={spike && r.week >= spike ? c.accent : c.gray} />
              ))}
            </Bar>
          ) : (
            <Line type="monotone" dataKey="pct" stroke={c.accent} strokeWidth={2} dot={false} activeDot={{ r: 4 }} />
          )}
          {spike && (
            <ReferenceLine
              x={shortDate(spike)}
              stroke={c.ai}
              strokeDasharray="4 3"
              label={{ value: 'rule change', position: 'insideTopLeft', fill: c.ai, fontSize: 11 }}
            />
          )}
        </ComposedChart>
      </ResponsiveContainer>
    </Frame>
  );
}

// 2. Where it sits ------------------------------------------------------------
function PayerChart({ data, slice, c }: { data: BriefingData; slice: Slice | null; c: typeof HUES.light }) {
  const rows = data.payers.map((p) => ({ ...p, short: p.payer.replace(' Health Plan', '').replace(' Health', '').replace(' Mutual', '') }));
  return (
    <Frame
      title="Denial rate by insurer — before vs now"
      caption="Gray is the 8-week baseline; blue is the last 6 weeks. One insurer moved."
      table={{ head: ['Insurer', 'Before', 'Now'], rows: rows.map((r) => [r.payer, `${r.rateBase}%`, `${r.rateRecent}%`]) }}
    >
      <ResponsiveContainer width="100%" height="100%">
        <BarChart data={rows} margin={{ top: 8, right: 8, bottom: 0, left: -18 }} barGap={2} barCategoryGap="28%">
          <CartesianGrid vertical={false} stroke={c.grid} />
          <XAxis dataKey="short" {...axis(c)} interval={0} />
          <YAxis {...axis(c)} width={44} tickFormatter={(v) => `${v}%`} />
          <Tooltip {...tip(c)} formatter={(v: unknown, name: unknown) => [`${Number(v)}%`, String(name) === 'rateBase' ? 'before' : 'now']} />
          <Bar dataKey="rateBase" name="rateBase" fill={c.gray} radius={[4, 4, 0, 0]} maxBarSize={22} />
          <Bar dataKey="rateRecent" name="rateRecent" radius={[4, 4, 0, 0]} maxBarSize={22}>
            {rows.map((r) => (
              <Cell key={r.payer} fill={!slice?.payer || r.payer === slice.payer ? c.accent : c.gray} />
            ))}
          </Bar>
        </BarChart>
      </ResponsiveContainer>
    </Frame>
  );
}

// 3. The money ----------------------------------------------------------------
function RecoveryChart({ data, c, title }: { data: BriefingData; c: typeof HUES.light; title: string }) {
  const total = data.recovery.reduce((t, b) => t + b.billed, 0);
  const one = Object.fromEntries(data.recovery.map((b) => [b.bucket, b.billed])) as Record<string, number>;
  return (
    <Frame
      title={`Where the money stands — ${title}`}
      caption={`${money(total)} denied since the baseline began. Orange is still recoverable if appeals are filed.`}
      table={{ head: ['Status', 'Claims', 'Billed'], rows: data.recovery.map((b) => [b.bucket, b.claims, money(b.billed)]) }}
    >
      <div className="flex h-full flex-col justify-center gap-3">
        <ResponsiveContainer width="100%" height={56}>
          <BarChart data={[one]} layout="vertical" margin={{ top: 0, right: 8, bottom: 0, left: 8 }} barCategoryGap={0}>
            <XAxis type="number" hide />
            <YAxis type="category" hide dataKey={() => ''} />
            <Tooltip {...tip(c)} formatter={(v: unknown, name: unknown) => [money(Number(v)), String(name)]} />
            {RECOVERY_ORDER.filter((b) => one[b]).map((b, i, arr) => (
              <Bar
                key={b}
                dataKey={b}
                stackId="m"
                fill={c[RECOVERY_HUE[b]]}
                stroke="var(--color-panel)"
                strokeWidth={2}
                radius={i === 0 ? [6, 0, 0, 6] : i === arr.length - 1 ? [0, 6, 6, 0] : 0}
              />
            ))}
          </BarChart>
        </ResponsiveContainer>
        <ul className="grid grid-cols-2 gap-x-4 gap-y-1.5 text-xs sm:grid-cols-3">
          {data.recovery.map((b) => (
            <li key={b.bucket} className="flex items-center gap-2">
              <span className="h-2.5 w-2.5 shrink-0 rounded-sm" style={{ background: c[RECOVERY_HUE[b.bucket]] }} />
              <span className="text-muted">{b.bucket}</span>
              <span className="tnum ml-auto font-semibold text-ink">{moneyShort(b.billed)}</span>
            </li>
          ))}
        </ul>
      </div>
    </Frame>
  );
}

// 4. Expiring -------------------------------------------------------------------
function ExpiringChart({ data, c }: { data: BriefingData; c: typeof HUES.light }) {
  const rows = data.expiring.map((e) => ({ ...e, short: e.payer.replace(' Health Plan', '').replace(' Health', '').replace(' Mutual', '') }));
  const total = rows.reduce((t, r) => t + r.billed, 0);
  return (
    <Frame
      title="Appeals about to expire, by insurer"
      caption={`${money(total)} of unfiled appeals close within 14 days. Nobody has to find these — she did.`}
      table={{ head: ['Insurer', 'Claims', 'Billed', 'First deadline'], rows: rows.map((r) => [r.payer, r.claims, money(r.billed), shortDate(r.firstDeadline)]) }}
    >
      <ResponsiveContainer width="100%" height="100%">
        <BarChart data={rows} layout="vertical" margin={{ top: 4, right: 56, bottom: 0, left: 8 }} barCategoryGap="30%">
          <CartesianGrid horizontal={false} stroke={c.grid} />
          <XAxis type="number" hide />
          <YAxis type="category" dataKey="short" {...axis(c)} width={70} />
          <Tooltip {...tip(c)} formatter={(v: unknown) => [money(Number(v)), 'unfiled, expiring']} />
          <Bar dataKey="billed" fill={c.accent} radius={[0, 4, 4, 0]} maxBarSize={18} label={{ position: 'right', fill: c.ink, fontSize: 11, formatter: (v: unknown) => moneyShort(Number(v)) }} />
        </BarChart>
      </ResponsiveContainer>
    </Frame>
  );
}