import React, { useMemo, useRef, useState } from "react";

// --- Helpers ---------------------------------------------------------------
const currency = (n: number) =>
  (isFinite(n) ? n : 0).toLocaleString(undefined, {
    style: "currency",
    currency: "USD",
    maximumFractionDigits: 0,
  });

const clamp = (v: number, min: number, max: number) => Math.min(max, Math.max(min, v));

// Map 1..5 to human-friendly week labels
const weekLabel = (w: number) =>
  ({ 1: "1st", 2: "2nd", 3: "3rd", 4: "4th", 5: "5th" } as Record<number, string>)[w] ?? `${w}th`;

const months = [
  "January",
  "February",
  "March",
  "April",
  "May",
  "June",
  "July",
  "August",
  "September",
  "October",
  "November",
  "December",
];

// Approximate how many weeks between (month, week) pairs (inclusive)
function approxWeeksBetween(
  startMonthIdx: number,
  startWeek: number,
  endMonthIdx: number,
  endWeek: number
) {
  const weeksPerMonth = 4.34524; // avg weeks per month
  const start = startMonthIdx + (startWeek - 1) / 5;
  const end = endMonthIdx + (endWeek - 1) / 5;
  const monthsBetween = Math.max(0, end - start);
  return Math.max(0, Math.round(monthsBetween * weeksPerMonth + 1));
}

// File download helper
function downloadText(filename: string, text: string) {
  const blob = new Blob([text], { type: "application/json" });
  const url = URL.createObjectURL(blob);
  const a = document.createElement("a");
  a.href = url;
  a.download = filename;
  a.click();
  URL.revokeObjectURL(url);
}

// Generic labeled number+slider input pair
function NumberSlider({
  label,
  value,
  onChange,
  min = 0,
  max = 100,
  step = 1,
  help,
  id,
}: {
  label: string;
  value: number;
  onChange: (v: number) => void;
  min?: number;
  max?: number;
  step?: number;
  help?: string;
  id?: string;
}) {
  const sliderId = id ?? label.replace(/\s+/g, "-").toLowerCase();
  return (
    <div className="space-y-2">
      <div className="flex items-baseline justify-between">
        <label htmlFor={sliderId} className="text-sm font-medium text-gray-800">
          {label}
        </label>
        <input
          type="number"
          inputMode="decimal"
          className="w-36 rounded-xl border border-gray-300 px-3 py-1 text-right shadow-sm focus:border-blue-500 focus:outline-none"
          value={Number.isFinite(value) ? value : 0}
          min={min}
          max={max}
          step={step}
          onChange={(e) => onChange(clamp(parseFloat(e.target.value || "0"), min, max))}
        />
      </div>
      <input
        id={sliderId}
        type="range"
        min={min}
        max={max}
        step={step}
        className="w-full accent-blue-600"
        value={Number.isFinite(value) ? value : 0}
        onChange={(e) => onChange(clamp(parseFloat(e.target.value || "0"), min, max))}
      />
      {help && <p className="text-xs text-gray-500">{help}</p>}
    </div>
  );
}

// --- Main App --------------------------------------------------------------
export default function BaseballLeagueCostEstimator() {
  // Fixed costs: name + amount
  const [fixedCosts, setFixedCosts] = useState<Array<{ id: string; name: string; amount: number }>>([
    { id: crypto.randomUUID(), name: "Insurance", amount: 1500 },
    { id: crypto.randomUUID(), name: "Commissioner", amount: 2000 },
  ]);

  // Variables
  const [teams, setTeams] = useState(12);
  const [gamesPerTeam, setGamesPerTeam] = useState(10); // number of games per team
  const [umpiresPerGame, setUmpiresPerGame] = useState(2);
  const [costPerUmpPerGame, setCostPerUmpPerGame] = useState(70);
  const [avgTeamSize, setAvgTeamSize] = useState(12);

  // Per-game consumables
  const [ballsPerGame, setBallsPerGame] = useState(4);
  const [costPerDozenBalls, setCostPerDozenBalls] = useState(60);

  // Season window
  const [startMonth, setStartMonth] = useState(4); // 0-indexed; May
  const [startWeek, setStartWeek] = useState(1);
  const [endMonth, setEndMonth] = useState(7); // August
  const [endWeek, setEndWeek] = useState(4);

  // Fields table rows: name, pct of games, cost per game (optional)
  const [fields, setFields] = useState<Array<{ id: string; name: string; pct: number; costPerGame: number }>>([
    { id: crypto.randomUUID(), name: "Main Park #1", pct: 60, costPerGame: 40 },
    { id: crypto.randomUUID(), name: "Riverside #2", pct: 40, costPerGame: 25 },
  ]);

  // Derived calculations
  const fixedCostTotal = useMemo(
    () => fixedCosts.reduce((sum, fc) => sum + (Number(fc.amount) || 0), 0),
    [fixedCosts]
  );

  // Total league games, given each game involves exactly two teams
  const totalGames = useMemo(() => (teams || 0) * (gamesPerTeam || 0) / 2, [teams, gamesPerTeam]);

  // Scheduling references (games-per-opponent distribution)
  const opponentsPerTeam = useMemo(() => Math.max(0, (teams || 0) - 1), [teams]);
  const gamesPerOpponentExact = useMemo(() => {
    if (!opponentsPerTeam) return 0;
    return (gamesPerTeam || 0) / opponentsPerTeam;
  }, [gamesPerTeam, opponentsPerTeam]);
  const gamesPerOpponentFloor = useMemo(() => Math.floor(gamesPerOpponentExact), [gamesPerOpponentExact]);
  const remainderOpponents = useMemo(() => {
    if (!opponentsPerTeam) return 0;
    return (gamesPerTeam || 0) % opponentsPerTeam;
  }, [gamesPerTeam, opponentsPerTeam]);

  const gamesVsEachOther = useMemo(() => {
    if (!teams || teams < 2) return 0;
    return (gamesPerTeam || 0) / (teams - 1);
  }, [teams, gamesPerTeam]);

  const umpireCostTotal = useMemo(
    () => (totalGames || 0) * (umpiresPerGame || 0) * (costPerUmpPerGame || 0),
    [totalGames, umpiresPerGame, costPerUmpPerGame]
  );

  const fieldsPctSum = useMemo(() => fields.reduce((s, f) => s + (Number(f.pct) || 0), 0), [fields]);

  const fieldRentalCostTotal = useMemo(() => {
    const totalPct = fieldsPctSum || 100;
    const normalized = fields.map((f) => ({ ...f, w: (Number(f.pct) || 0) / totalPct }));
    return normalized.reduce(
      (sum, f) => sum + (totalGames || 0) * f.w * (Number(f.costPerGame) || 0),
      0
    );
  }, [fields, fieldsPctSum, totalGames]);

  // Per-game baseballs cost
  const perBallCost = useMemo(() => (Number(costPerDozenBalls) || 0) / 12, [costPerDozenBalls]);
  const baseballsCostPerGame = useMemo(() => (Number(ballsPerGame) || 0) * perBallCost, [ballsPerGame, perBallCost]);
  const baseballsCostTotal = useMemo(() => (totalGames || 0) * baseballsCostPerGame, [totalGames, baseballsCostPerGame]);

  // Split costs: league (fixed + fields + consumables) vs umpires
  const leagueCostsTotal = useMemo(
    () => fixedCostTotal + fieldRentalCostTotal + baseballsCostTotal,
    [fixedCostTotal, fieldRentalCostTotal, baseballsCostTotal]
  );

  const grandTotal = leagueCostsTotal + umpireCostTotal;

  const costPerTeam = useMemo(() => (teams > 0 ? grandTotal / teams : 0), [grandTotal, teams]);
  const costPerTeamLeague = useMemo(() => (teams > 0 ? leagueCostsTotal / teams : 0), [leagueCostsTotal, teams]);
  const costPerTeamUmpires = useMemo(() => (teams > 0 ? umpireCostTotal / teams : 0), [umpireCostTotal, teams]);

  const costPerPlayer = useMemo(
    () => (teams > 0 && avgTeamSize > 0 ? grandTotal / (teams * avgTeamSize) : 0),
    [grandTotal, teams, avgTeamSize]
  );

  const approxWeeks = useMemo(
    () => approxWeeksBetween(startMonth, startWeek, endMonth, endWeek),
    [startMonth, startWeek, endMonth, endWeek]
  );

  const gamesPerWeekPerTeam = useMemo(() => {
    if (!approxWeeks) return 0;
    return (gamesPerTeam || 0) / approxWeeks;
  }, [gamesPerTeam, approxWeeks]);

  const gamesPerWeekLeague = useMemo(() => {
    if (!approxWeeks) return 0;
    return (totalGames || 0) / approxWeeks;
  }, [totalGames, approxWeeks]);

  // Mutators
  const addFixed = () => setFixedCosts((x) => [...x, { id: crypto.randomUUID(), name: "New Fixed Cost", amount: 0 }]);
  const removeFixed = (id: string) => setFixedCosts((x) => x.filter((r) => r.id !== id));

  const addField = () =>
    setFields((x) => [
      ...x,
      { id: crypto.randomUUID(), name: `Field ${x.length + 1}`, pct: 0, costPerGame: 0 },
    ]);
  const removeField = (id: string) => setFields((x) => x.filter((r) => r.id !== id));

  const pctWarning = fieldsPctSum !== 100;

  // --- Import/Export -------------------------------------------------------
  type SaveShape = {
    version: 1;
    data: {
      fixedCosts: Array<{ name: string; amount: number }>;
      teams: number;
      gamesPerTeam: number;
      umpiresPerGame: number;
      costPerUmpPerGame: number;
      avgTeamSize: number;
      ballsPerGame: number;
      costPerDozenBalls: number;
      startMonth: number; startWeek: number; endMonth: number; endWeek: number;
      fields: Array<{ name: string; pct: number; costPerGame: number }>;
    };
  };

  const fileInputRef = useRef<HTMLInputElement>(null);

  const exportJSON = () => {
    const payload: SaveShape = {
      version: 1,
      data: {
        fixedCosts: fixedCosts.map(({ name, amount }) => ({ name, amount })),
        teams,
        gamesPerTeam,
        umpiresPerGame,
        costPerUmpPerGame,
        avgTeamSize,
        ballsPerGame,
        costPerDozenBalls,
        startMonth,
        startWeek,
        endMonth,
        endWeek,
        fields: fields.map(({ name, pct, costPerGame }) => ({ name, pct, costPerGame })),
      },
    };
    const ts = new Date();
    const pad = (n: number) => String(n).padStart(2, "0");
    const fname = `league-cost-estimator-${ts.getFullYear()}${pad(ts.getMonth()+1)}${pad(ts.getDate())}-${pad(ts.getHours())}${pad(ts.getMinutes())}.json`;
    downloadText(fname, JSON.stringify(payload, null, 2));
  };

  const applyImported = (s: SaveShape["data"]) => {
    setFixedCosts((s.fixedCosts || []).map(fc => ({ id: crypto.randomUUID(), ...fc })));
    setTeams(s.teams ?? teams);
    setGamesPerTeam(s.gamesPerTeam ?? gamesPerTeam);
    setUmpiresPerGame(s.umpiresPerGame ?? umpiresPerGame);
    setCostPerUmpPerGame(s.costPerUmpPerGame ?? costPerUmpPerGame);
    setAvgTeamSize(s.avgTeamSize ?? avgTeamSize);
    setBallsPerGame(s.ballsPerGame ?? ballsPerGame);
    setCostPerDozenBalls(s.costPerDozenBalls ?? costPerDozenBalls);
    setStartMonth(s.startMonth ?? startMonth);
    setStartWeek(s.startWeek ?? startWeek);
    setEndMonth(s.endMonth ?? endMonth);
    setEndWeek(s.endWeek ?? endWeek);
    setFields((s.fields || []).map(f => ({ id: crypto.randomUUID(), ...f })));
  };

  const importFromFile = async (file: File) => {
    try {
      const text = await file.text();
      const parsed = JSON.parse(text);
      if (!parsed || parsed.version !== 1 || !parsed.data) throw new Error("Invalid or unsupported file format.");
      applyImported(parsed.data);
      alert("Import successful ✅");
    } catch (err: any) {
      console.error(err);
      alert("Import failed: " + (err?.message || String(err)));
    } finally {
      if (fileInputRef.current) fileInputRef.current.value = "";
    }
  };

  const onClickImport = () => fileInputRef.current?.click();

  return (
    <div className="mx-auto max-w-6xl p-6">
      <header className="mb-6 flex items-center justify-between">
        <h1 className="text-2xl font-bold">Baseball League Cost Estimator</h1>
        <div className="flex items-center gap-2">
          <input
            ref={fileInputRef}
            type="file"
            accept="application/json"
            className="hidden"
            onChange={(e) => {
              const f = e.target.files?.[0];
              if (f) importFromFile(f);
            }}
          />
          <button onClick={onClickImport} className="rounded-xl border border-gray-300 bg-white px-3 py-1.5 text-sm shadow hover:bg-gray-50">Import</button>
          <button onClick={exportJSON} className="rounded-xl bg-blue-600 px-3 py-1.5 text-sm font-medium text-white shadow hover:bg-blue-700">Export</button>
        </div>
      </header>

      <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
        {/* Left column: Variables */}
        <section className="lg:col-span-2 space-y-6">
          {/* League Basics */}
          <div className="rounded-2xl border border-gray-200 bg-white p-5 shadow-sm">
            <h2 className="mb-4 text-lg font-semibold">League Basics</h2>
            <div className="grid grid-cols-1 gap-6 sm:grid-cols-2">
              <NumberSlider
                label="Number of teams"
                value={teams}
                onChange={setTeams}
                min={0}
                max={50}
              />

              <NumberSlider
                label="Games per team"
                value={gamesPerTeam}
                onChange={setGamesPerTeam}
                min={0}
                max={100}
                step={1}
                help={`League total games: ${totalGames}`}
              />

              <NumberSlider
                label="Umpires per game"
                value={umpiresPerGame}
                onChange={setUmpiresPerGame}
                min={0}
                max={6}
                step={1}
              />

              <NumberSlider
                label="Cost per umpire per game ($)"
                value={costPerUmpPerGame}
                onChange={setCostPerUmpPerGame}
                min={0}
                max={300}
                step={1}
              />

              <NumberSlider
                label="Average team size (players)"
                value={avgTeamSize}
                onChange={setAvgTeamSize}
                min={1}
                max={30}
                step={1}
                help="Used for per-player cost"
              />

              <NumberSlider
                label="Baseballs used per game"
                value={ballsPerGame}
                onChange={setBallsPerGame}
                min={0}
                max={24}
                step={1}
              />

              <NumberSlider
                label="Cost of baseballs per dozen ($)"
                value={costPerDozenBalls}
                onChange={setCostPerDozenBalls}
                min={0}
                max={200}
                step={1}
                help={`≈ ${currency(perBallCost)} per ball • ${currency(baseballsCostPerGame)} per game`}
              />
            </div>

            {/* Scheduling reference */}
            <div className="mt-4 rounded-xl border border-gray-100 bg-gray-50 p-3 text-sm">
              <div className="flex flex-wrap gap-x-6 gap-y-1">
                <div>Opponents per team: <span className="font-medium">{opponentsPerTeam}</span></div>
                <div>Games per opponent (avg): <span className="font-medium">{gamesPerOpponentExact.toFixed(2)}</span></div>
              </div>
              {opponentsPerTeam > 0 && (
                <div className="mt-1 text-gray-700">
                  Distribution (as even as possible): each team plays <span className="font-medium">{remainderOpponents}</span> opponents <span className="font-medium">{gamesPerOpponentFloor + 1}×</span> and <span className="font-medium">{opponentsPerTeam - remainderOpponents}</span> opponents <span className="font-medium">{gamesPerOpponentFloor}×</span>.
                </div>
              )}
              <div className="mt-1 text-gray-500">Total league games computed as teams × gamesPerTeam ÷ 2.</div>
            </div>
          </div>

          {/* Season Window */}
          <div className="rounded-2xl border border-gray-200 bg-white p-5 shadow-sm">
            <h2 className="mb-4 text-lg font-semibold">Season Window</h2>
            <div className="grid grid-cols-1 items-end gap-4 sm:grid-cols-4">
              <div className="space-y-2">
                <label className="text-sm font-medium text-gray-800">Start month</label>
                <select
                  className="w-full rounded-xl border border-gray-300 px-3 py-2 shadow-sm focus:border-blue-500 focus:outline-none"
                  value={startMonth}
                  onChange={(e) => setStartMonth(parseInt(e.target.value))}
                >
                  {months.map((m, i) => (
                    <option key={m} value={i}>
                      {m}
                    </option>
                  ))}
                </select>
              </div>
              <div className="space-y-2">
                <label className="text-sm font-medium text-gray-800">Start week</label>
                <select
                  className="w-full rounded-xl border border-gray-300 px-3 py-2 shadow-sm focus:border-blue-500 focus:outline-none"
                  value={startWeek}
                  onChange={(e) => setStartWeek(parseInt(e.target.value))}
                >
                  {[1, 2, 3, 4, 5].map((w) => (
                    <option key={w} value={w}>
                      {weekLabel(w)}
                    </option>
                  ))}
                </select>
              </div>

              <div className="space-y-2">
                <label className="text-sm font-medium text-gray-800">End month</label>
                <select
                  className="w-full rounded-xl border border-gray-300 px-3 py-2 shadow-sm focus:border-blue-500 focus:outline-none"
                  value={endMonth}
                  onChange={(e) => setEndMonth(parseInt(e.target.value))}
                >
                  {months.map((m, i) => (
                    <option key={m} value={i}>
                      {m}
                    </option>
                  ))}
                </select>
              </div>
              <div className="space-y-2">
                <label className="text-sm font-medium text-gray-800">End week</label>
                <select
                  className="w-full rounded-xl border border-gray-300 px-3 py-2 shadow-sm focus:border-blue-500 focus:outline-none"
                  value={endWeek}
                  onChange={(e) => setEndWeek(parseInt(e.target.value))}
                >
                  {[1, 2, 3, 4, 5].map((w) => (
                    <option key={w} value={w}>
                      {weekLabel(w)}
                    </option>
                  ))}
                </select>
              </div>
            </div>
            <div className="mt-3 grid grid-cols-1 gap-2 text-sm text-gray-700 sm:grid-cols-2 lg:grid-cols-4">
              <div><span className="text-gray-600">Approx. season length:</span> <span className="font-medium">{approxWeeks} weeks</span></div>
              <div><span className="text-gray-600">Games/week per team:</span> <span className="font-medium">{gamesPerWeekPerTeam.toFixed(2)}</span></div>
              <div><span className="text-gray-600">Games/week league-wide:</span> <span className="font-medium">{gamesPerWeekLeague.toFixed(2)}</span></div>
              <div><span className="text-gray-600">Games vs each opponent/team:</span> <span className="font-medium">{gamesVsEachOther.toFixed(2)}</span></div>
            </div>
          </div>

          {/* Fields Table */}
          <div className="rounded-2xl border border-gray-200 bg-white p-5 shadow-sm">
            <div className="mb-4 flex items-center justify-between">
              <h2 className="text-lg font-semibold">Fields & Game Allocation</h2>
              <button
                onClick={addField}
                className="rounded-xl bg-blue-600 px-3 py-1.5 text-sm font-medium text-white shadow hover:bg-blue-700"
              >
                + Add field
              </button>
            </div>
            <div className="overflow-x-auto">
              <table className="w-full table-auto">
                <thead>
                  <tr className="text-left text-sm text-gray-500">
                    <th className="p-2">Field name</th>
                    <th className="p-2">% of games</th>
                    <th className="p-2">Cost per game ($)</th>
                    <th className="p-2"></th>
                  </tr>
                </thead>
                <tbody>
                  {fields.map((f) => (
                    <tr key={f.id} className="border-t border-gray-100">
                      <td className="p-2">
                        <input
                          className="w-full rounded-lg border border-gray-300 px-3 py-2 text-sm focus:border-blue-500 focus:outline-none"
                          value={f.name}
                          onChange={(e) =>
                            setFields((rows) => rows.map((r) => (r.id === f.id ? { ...r, name: e.target.value } : r)))
                          }
                        />
                      </td>
                      <td className="p-2">
                        <input
                          type="number"
                          className="w-28 rounded-lg border border-gray-300 px-3 py-2 text-right text-sm focus:border-blue-500 focus:outline-none"
                          min={0}
                          max={100}
                          step={1}
                          value={f.pct}
                          onChange={(e) =>
                            setFields((rows) =>
                              rows.map((r) => (r.id === f.id ? { ...r, pct: clamp(parseFloat(e.target.value || "0"), 0, 100) } : r))
                            )
                          }
                        />
                      </td>
                      <td className="p-2">
                        <input
                          type="number"
                          className="w-40 rounded-lg border border-gray-300 px-3 py-2 text-right text-sm focus:border-blue-500 focus:outline-none"
                          min={0}
                          step={1}
                          value={f.costPerGame}
                          onChange={(e) =>
                            setFields((rows) =>
                              rows.map((r) =>
                                r.id === f.id
                                  ? { ...r, costPerGame: clamp(parseFloat(e.target.value || "0"), 0, 10000) }
                                  : r
                              )
                            )
                          }
                        />
                      </td>
                      <td className="p-2 text-right">
                        <button
                          onClick={() => removeField(f.id)}
                          className="text-sm text-red-600 hover:underline"
                        >
                          Remove
                        </button>
                      </td>
                    </tr>
                  ))}
                </tbody>
                <tfoot>
                  <tr className="border-t border-gray-200 text-sm">
                    <td className="p-2 font-medium text-gray-700">Totals</td>
                    <td className="p-2 font-medium {pctWarning ? 'text-red-600' : 'text-gray-700'}">{fieldsPctSum}%</td>
                    <td className="p-2 font-medium text-gray-700">—</td>
                    <td></td>
                  </tr>
                </tfoot>
              </table>
            </div>
            {pctWarning && (
              <div className="mt-3 rounded-xl border border-yellow-300 bg-yellow-50 px-3 py-2 text-sm text-yellow-900">
                Heads up: your field allocation adds to {fieldsPctSum}%. Calculations will normalize
                percentages to 100%.
              </div>
            )}
          </div>
        </section>

        {/* Right column: Fixed costs + Summary */}
        <section className="space-y-6">
          {/* Fixed costs */}
          <div className="rounded-2xl border border-gray-200 bg-white p-5 shadow-sm">
            <div className="mb-4 flex items-center justify-between">
              <h2 className="text-lg font-semibold">Fixed Costs</h2>
              <button
                onClick={addFixed}
                className="rounded-xl bg-blue-600 px-3 py-1.5 text-sm font-medium text-white shadow hover:bg-blue-700"
              >
                + Add item
              </button>
            </div>
            <div className="space-y-3">
              {fixedCosts.map((fc) => (
                <div key={fc.id} className="grid grid-cols-5 items-center gap-2">
                  <input
                    className="col-span-3 rounded-lg border border-gray-300 px-3 py-2 text-sm focus:border-blue-500 focus:outline-none"
                    value={fc.name}
                    onChange={(e) =>
                      setFixedCosts((rows) => rows.map((r) => (r.id === fc.id ? { ...r, name: e.target.value } : r)))
                    }
                  />
                  <input
                    type="number"
                    className="col-span-2 rounded-lg border border-gray-300 px-3 py-2 text-right text-sm focus:border-blue-500 focus:outline-none"
                    min={0}
                    step={1}
                    value={fc.amount}
                    onChange={(e) =>
                      setFixedCosts((rows) =>
                        rows.map((r) =>
                          r.id === fc.id
                            ? { ...r, amount: clamp(parseFloat(e.target.value || "0"), 0, 1_000_000) }
                            : r
                        )
                      )
                    }
                  />
                  <div className="col-span-5 flex justify-end">
                    <button
                      onClick={() => removeFixed(fc.id)}
                      className="text-sm text-red-600 hover:underline"
                    >
                      Remove
                    </button>
                  </div>
                </div>
              ))}
            </div>
            <div className="mt-4 flex items-center justify-between border-t pt-3 text-sm">
              <div className="font-medium text-gray-700">Fixed cost total</div>
              <div className="font-semibold">{currency(fixedCostTotal)}</div>
            </div>
          </div>

          {/* Summary */}
          <div className="rounded-2xl border border-gray-200 bg-white p-5 shadow-sm">
            <h2 className="mb-4 text-lg font-semibold">Summary</h2>
            <div className="space-y-2 text-sm">
              <div className="flex justify-between"><span>Umpire costs</span><span className="font-medium">{currency(umpireCostTotal)}</span></div>
              <div className="flex justify-between"><span>Field rental costs</span><span className="font-medium">{currency(fieldRentalCostTotal)}</span></div>
              <div className="flex justify-between"><span>Baseballs (per-game consumables)</span><span className="font-medium">{currency(baseballsCostTotal)}</span></div>
              <div className="flex justify-between"><span>Fixed costs</span><span className="font-medium">{currency(fixedCostTotal)}</span></div>
              <div className="flex justify-between border-t pt-2">
                <span>League costs subtotal</span>
                <span className="font-medium">{currency(leagueCostsTotal)}</span>
              </div>
              <div className="flex justify-between border-t pt-2 text-base">
                <span className="font-semibold">Grand total</span>
                <span className="font-bold">{currency(grandTotal)}</span>
              </div>
            </div>
            <div className="mt-4 space-y-2 rounded-xl bg-gray-50 p-3 text-sm">
              <div className="flex justify-between"><span>Per team to league</span><span className="font-semibold">{currency(costPerTeamLeague)}</span></div>
              <div className="flex justify-between"><span>Per team to umpires</span><span className="font-semibold">{currency(costPerTeamUmpires)}</span></div>
              <div className="flex justify-between"><span>Per team (total)</span><span className="font-semibold">{currency(costPerTeam)}</span></div>
              <div className="flex justify-between"><span>Per player (avg team size {avgTeamSize})</span><span className="font-semibold">{currency(costPerPlayer)}</span></div>
            </div>

            <div className="mt-4 text-xs text-gray-500">
              Notes:
              <ul className="list-disc pl-5">
                <li>League total games = teams × games per team ÷ 2.</li>
                <li>Field cost = total games × % allocation × per-field cost per game.</li>
                <li>Percentages are normalized if they don't add up to 100%.</li>
                <li>Season window drives weekly rates only; it doesn't alter totals.</li>
              </ul>
            </div>
          </div>
        </section>
      </div>

      <footer className="mt-8 text-center text-xs text-gray-500">
        Built for quick budgeting. Adjust anything and the math updates instantly.
      </footer>
    </div>
  );
}