"use client";

import {
  LineChart,
  Line,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  ResponsiveContainer,
  Legend,
  ReferenceArea,
} from "recharts";
import { computeOutages, outageLookup, formatOutageDuration } from "@/lib/outage";

export interface TodaySample {
  recordedAt: string;
  localTime: string;
  isOpen: boolean;
  waitMinutes: number | null;
  fastLaneMinutes: number | null;
}

interface Props {
  samples: TodaySample[];
  hasFastLane: boolean;
}

const TIME_FMT = new Intl.DateTimeFormat([], {
  hour: "2-digit",
  minute: "2-digit",
  hour12: false,
});

export default function WaitTimeTodayChart({ samples, hasFastLane }: Props) {
  const outages = computeOutages(samples);
  const outageByTime = outageLookup(samples, outages);

  // Show the Fast Lane line if either the ride metadata flags it as a Fast
  // Lane ride OR we have any actual Fast Lane data in today's samples. The
  // metadata flag can lag (or read false even when SF is reporting waits),
  // so the data-driven check rescues those rides.
  const showFastLane = hasFastLane || samples.some((s) => s.fastLaneMinutes !== null);

  // X-axis time is rendered in the viewer's local timezone (Intl with no
  // tz arg) so an Eastern-time user sees ET regardless of which park.
  // Each point also carries its outage (if any) so the custom tooltip can
  // render "Outage #N — Hh Mm" without re-scanning.
  const data = samples.map((s) => {
    const time = TIME_FMT.format(new Date(s.recordedAt));
    const outage = !s.isOpen ? outageByTime.get(time) ?? null : null;
    return {
      time,
      wait: s.isOpen ? s.waitMinutes : null,
      fl: s.isOpen ? s.fastLaneMinutes : null,
      outageN: outage?.n ?? null,
      outageDurationMin: outage?.durationMin ?? null,
    };
  });

  const tickInterval = Math.max(1, Math.floor(data.length / 8));

  return (
    <div style={{ width: "100%", height: 280 }}>
      <ResponsiveContainer>
        {/* top margin leaves room for outage labels rendered with position="top" */}
        <LineChart data={data} margin={{ top: 24, right: 16, left: 0, bottom: 4 }}>
          <CartesianGrid stroke="#272727" strokeDasharray="3 3" vertical={false} />
          <XAxis
            dataKey="time"
            stroke="#737373"
            tick={{ fontSize: 11, fill: "#737373" }}
            interval={tickInterval}
            tickLine={false}
          />
          <YAxis
            stroke="#737373"
            tick={{ fontSize: 11, fill: "#737373" }}
            tickLine={false}
            axisLine={false}
            domain={[0, "auto"]}
            padding={{ bottom: 6 }}
            label={{ value: "min", position: "insideLeft", angle: -90, offset: 16, style: { fontSize: 10, fill: "#737373" } }}
          />
          {/* Outage markers — render before the lines so they sit underneath. */}
          {outages.map((o) => (
            <ReferenceArea
              key={`outage-${o.n}`}
              x1={o.startTimeLabel}
              x2={o.endTimeLabel}
              fill="#ff4d8d"
              fillOpacity={0.08}
              stroke="#ff4d8d"
              strokeOpacity={0.35}
              strokeDasharray="3 3"
              ifOverflow="extendDomain"
              label={{
                value: `#${o.n} · ${formatOutageDuration(o.durationMin)}`,
                position: "top",
                fill: "#ff4d8d",
                fontSize: 10,
                fontWeight: 600,
                offset: 4,
              }}
            />
          ))}
          <Tooltip content={<RideTooltip hasFastLane={showFastLane} />} />
          <Legend wrapperStyle={{ fontSize: "0.72rem", paddingTop: 4 }} />
          <Line
            name="Wait"
            type="monotone"
            dataKey="wait"
            stroke="#4ade80"
            strokeWidth={2}
            dot={false}
            connectNulls={false}
            isAnimationActive={false}
          />
          {showFastLane && (
            <Line
              name="Fast Lane"
              type="monotone"
              dataKey="fl"
              stroke="#ff4d8d"
              strokeWidth={2}
              dot={false}
              connectNulls={false}
              isAnimationActive={false}
            />
          )}
        </LineChart>
      </ResponsiveContainer>
    </div>
  );
}

// ── Custom tooltip ─────────────────────────────────────────────────────────
// When hovering on an outage span, replace the standard wait/Fast Lane rows
// with a single "Outage #N — duration" line. Otherwise show the per-series
// values, formatting 0 explicitly as "walk-on".

interface TooltipDatum {
  outageN: number | null;
  outageDurationMin: number | null;
}

interface TooltipEntry {
  value?: number | null;
  name?: string | number;
  dataKey?: string | number;
  color?: string;
  payload?: TooltipDatum;
}

interface RideTooltipProps {
  active?: boolean;
  payload?: TooltipEntry[];
  label?: string | number;
  hasFastLane: boolean;
}

function RideTooltip({ active, payload, label, hasFastLane }: RideTooltipProps) {
  if (!active || !payload || payload.length === 0) return null;

  const datum = payload[0]?.payload;
  const cardStyle: React.CSSProperties = {
    background: "#1c1c1c",
    border: "1px solid #333",
    borderRadius: 6,
    fontSize: "0.75rem",
    color: "#f5f5f5",
    padding: "8px 10px",
    lineHeight: 1.4,
  };

  if (datum?.outageN && datum.outageDurationMin !== null) {
    return (
      <div style={cardStyle}>
        <div style={{ color: "#b0b0b0", fontSize: "0.68rem", marginBottom: 2 }}>{label}</div>
        <div style={{ color: "#ff4d8d", fontWeight: 600 }}>
          Outage #{datum.outageN} — {formatOutageDuration(datum.outageDurationMin)}
        </div>
      </div>
    );
  }

  return (
    <div style={cardStyle}>
      <div style={{ color: "#b0b0b0", fontSize: "0.68rem", marginBottom: 4 }}>{label}</div>
      {payload.map((entry, i) => {
        const v = entry.value;
        const display =
          v === null || v === undefined
            ? "—"
            : v === 0
              ? "walk-on"
              : `${v} min`;
        const dotColor = entry.color ?? "#fff";
        return (
          <div key={String(entry.dataKey ?? i)} style={{ display: "flex", alignItems: "center", gap: 6 }}>
            <span style={{ width: 8, height: 2, background: dotColor, borderRadius: 1 }} />
            <span style={{ color: "#b0b0b0", flex: 1 }}>{entry.name}</span>
            <span style={{ fontWeight: 600 }}>{display}</span>
          </div>
        );
      })}
      {!hasFastLane && null}
    </div>
  );
}