"use client";

import { useState, useMemo, useEffect } from "react";
import { TrendingUp, TrendingDown, LayoutGrid, Sparkles, ChevronRight } from "lucide-react";
import { Sparkline } from "@/components/Sparkline";
import { MONTH_NAMES } from "@/lib/data";
import type { IncomeRow } from "@/lib/rows";
import { ZAR, ZAR2 } from "@/lib/utils";
import { ScrollFade } from "@/components/ScrollFade";

export function IncomeView({
  rows,
  palette,
  title,
}: {
  rows: IncomeRow[];
  palette: { income: string; profit: string; loss: string };
  /** The page heading. Rendered here rather than by the page because the YTD tiles have
   *  to sit beside it, and the tiles can only follow the status filter from in here. */
  title: React.ReactNode;
}) {
  const [view, setView] = useState<"cards" | "grid">("cards");
  const [sort, setSort] = useState<"profit" | "income">("profit");
  const [expanded, setExpanded] = useState<string | null>(null);
  // Machines the client has stood down show nothing but a flat row of zeros — they are
  // out of the fleet, not idle. Hidden by default, reachable behind the filter.
  const [status, setStatus] = useState<"active" | "all" | "inactive">("active");

  const visible = useMemo(
    () =>
      rows.filter((r) =>
        status === "all" ? true : status === "active" ? r.isActive : !r.isActive,
      ),
    [rows, status],
  );

  useEffect(() => {
    // A machine hidden by the filter must not stay stuck expanded.
    if (expanded && !visible.some((r) => r.id === expanded)) setExpanded(null);
  }, [visible, expanded]);

  const activeN = useMemo(() => rows.filter((r) => r.isActive).length, [rows]);
  const inactiveN = rows.length - activeN;

  const sorted = useMemo(() => {
    return [...visible].sort((a, b) =>
      sort === "profit" ? b.ytdProfit - a.ytdProfit : b.income - a.income
    );
  }, [visible, sort]);

  const totals = useMemo(() => {
    // Summed over what is VISIBLE, so the headline never disagrees with the list below it.
    const totalIncome = visible.reduce((s, r) => s + r.income, 0);
    const totalProfit = visible.reduce((s, r) => s + r.ytdProfit, 0);
    const profitable = visible.filter((r) => r.ytdProfit > 0).length;
    // VAT already inside the booked figures — booked amounts are VAT-inclusive, so this
    // is part of the income total and is called out rather than hidden.
    const invoiceVat = visible.reduce((s, r) => s + r.invoiceVat, 0);
    const invoiceIncome = visible.reduce((s, r) => s + r.invoiceIncome, 0);
    return { totalIncome, totalProfit, profitable, invoiceVat, invoiceIncome };
  }, [visible]);

  return (
    <>
      {/* The heading row lives HERE, not in the page. This component returns a fragment,
          so when the page put it inside its own `lg:flex-row` header, the toolbar, these
          tiles and the whole machine list all became flex SIBLINGS of the title and shared
          one line: the tiles were squeezed to ~150px columns whose text-2xl money spilled
          over itself, and the list was pushed off the side. Stacking until lg is what
          hides it — below lg this row is a column, so the mobile pass never saw it. */}
      <div className="flex flex-col lg:flex-row lg:items-end lg:justify-between gap-4 mb-6">
        {title}
        {/* grid, not flex-wrap: a wrapping flex row sizes tiles by CONTENT, which is the
            ragged-left-edge trap AGENTS.md records for /income/invoices.
            Full-width stacked on mobile, two-up from sm — same shape the dashboard
            cards already use there. */}
        <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
          <div className="bg-gradient-to-br from-[#00798C] to-[#003D5B] rounded-2xl px-5 py-3 text-white shadow-lg shadow-teal-500/20">
            <div className="text-xs text-white/80">YTD Income</div>
            <div className="text-2xl font-semibold tabular-nums">{ZAR(totals.totalIncome)}</div>
          </div>
          <div
            className={`bg-gradient-to-br ${
              totals.totalProfit >= 0 ? "from-[#EDAE49] to-[#D1495B]" : "from-[#D1495B] to-[#003D5B]"
            } rounded-2xl px-5 py-3 text-white shadow-lg`}
          >
            <div className="text-xs text-white/80">YTD Profit</div>
            <div className="text-2xl font-semibold tabular-nums">{ZAR(totals.totalProfit)}</div>
          </div>
        </div>
      </div>

      {/* Round 4 Part B.1/B.3/B.5: toolbar wraps onto two rows on mobile, controls collapse gracefully */}
      <div className="flex flex-col sm:flex-row sm:flex-wrap sm:items-center sm:justify-between gap-3 mb-5">
        <div className="flex items-center gap-2 text-xs text-gray-500 dark:text-gray-400 flex-wrap">
          <span className="px-2.5 py-1 rounded-md bg-[#00798C]/10 text-[#00798C] font-medium">
            {totals.profitable} profitable
          </span>
          <span className="px-2.5 py-1 rounded-md bg-[#D1495B]/10 text-[#D1495B] font-medium">
            {visible.length - totals.profitable} loss-making
          </span>
          {totals.invoiceVat > 0 && (
            <span className="px-2.5 py-1 rounded-md bg-[#EDAE49]/15 text-[#8a6420] dark:text-[#EDAE49] font-medium">
              includes {ZAR(totals.invoiceVat)} VAT
            </span>
          )}
          <span className="hidden md:inline">· sorted by {sort}</span>
        </div>
        {/* Round 4 Part B.3: Sort collapses to a select on mobile. View toggle stays as buttons. */}
        <div className="flex items-center gap-2 flex-wrap">
          <div className="flex items-center gap-1 p-0.5 rounded-lg bg-white dark:bg-white/5 border border-gray-200 dark:border-border">
            <button
              onClick={() => setView("cards")}
              aria-label="Cards view"
              className={`min-h-[44px] px-3 text-xs font-medium rounded-md transition flex items-center gap-1.5 ${
                view === "cards"
                  ? "bg-[#003D5B] text-white dark:bg-[#00798C]"
                  : "text-gray-500 dark:text-gray-400 hover:text-gray-900 dark:hover:text-white"
              }`}
            >
              <Sparkles className="w-3.5 h-3.5" /> Cards
            </button>
            <button
              onClick={() => setView("grid")}
              aria-label="Grid view"
              className={`min-h-[44px] px-3 text-xs font-medium rounded-md transition flex items-center gap-1.5 ${
                view === "grid"
                  ? "bg-[#003D5B] text-white dark:bg-[#00798C]"
                  : "text-gray-500 dark:text-gray-400 hover:text-gray-900 dark:hover:text-white"
              }`}
            >
              <LayoutGrid className="w-3.5 h-3.5" /> Grid
            </button>
          </div>
          <div className="hidden sm:flex items-center gap-1">
            <span className="text-xs text-gray-400 dark:text-text-soft mr-1">Sort:</span>
            {[
              { id: "profit", label: "Profit" },
              { id: "income", label: "Income" },
            ].map((s) => (
              <button
                key={s.id}
                onClick={() => setSort(s.id as typeof sort)}
                className={`min-h-[44px] px-2 text-xs font-medium rounded transition ${
                  sort === s.id ? "bg-[#EDAE49] text-white" : "text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-white/5"
                }`}
              >
                {s.label}
              </button>
            ))}
          </div>
          {/* Status filter. Stands down machines are hidden by default; this is the only
              way to see them, so the count is stated rather than leaving a silent gap. */}
          <div className="flex items-center gap-1 p-0.5 rounded-lg bg-white dark:bg-white/5 border border-gray-200 dark:border-white/5">
            {([
              { id: "active", label: "Active", n: activeN },
              { id: "all", label: "All", n: rows.length },
              { id: "inactive", label: "Inactive", n: inactiveN },
            ] as const).map((o) => (
              <button
                key={o.id}
                onClick={() => setStatus(o.id)}
                aria-pressed={status === o.id}
                className={`min-h-[44px] px-3 rounded-md text-xs font-medium transition ${
                  status === o.id
                    ? o.id === "inactive"
                      ? "bg-[#D1495B] text-white"
                      : "bg-[#003D5B] text-white dark:bg-[#00798C]"
                    : "text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-white/5"
                }`}
              >
                {o.label} <span className="opacity-60">({o.n})</span>
              </button>
            ))}
          </div>

          {/* Part B.3: mobile sort dropdown */}
          <div className="sm:hidden">
            <label className="sr-only" htmlFor="income-sort">Sort by</label>
            <select
              id="income-sort"
              value={sort}
              onChange={(e) => setSort(e.target.value as typeof sort)}
              className="min-h-[44px] px-3 text-xs rounded-lg border border-gray-200 dark:border-white/10 bg-white dark:bg-white/5"
            >
              <option value="profit">Sort by Profit</option>
              <option value="income">Sort by Income</option>
            </select>
          </div>
        </div>
      </div>

      {view === "cards" ? (
        <CardsView
          rows={sorted}
          expanded={expanded}
          setExpanded={setExpanded}
          palette={palette}
        />
      ) : (
        <GridView rows={sorted} />
      )}
    </>
  );
}

function CardsView({
  rows, expanded, setExpanded, palette,
}: {
  rows: IncomeRow[];
  expanded: string | null;
  setExpanded: (id: string | null) => void;
  palette: { income: string; profit: string; loss: string };
}) {
  return (
    <div className="space-y-2">
      {rows.map((r) => {
        const isOpen = expanded === r.id;
        const positive = r.ytdProfit >= 0;
        return (
          <div
            key={r.id}
            className="bg-white dark:bg-surface border border-gray-100 dark:border-border rounded-xl overflow-hidden shadow-sm hover:shadow-md transition"
          >
            <button
              onClick={() => setExpanded(isOpen ? null : r.id)}
              className="w-full text-left p-4"
            >
              {/* Row 1: code + name + sparkline + YTD + P/L pill + chevron */}
              <div className="flex items-center gap-3 sm:gap-4 min-h-[44px]">
                <span className="font-mono text-xs px-2 py-1 rounded-md bg-[#00798C]/10 text-[#00798C] font-semibold shrink-0">
                  {r.code}
                </span>
                {/* Round 4 Part B.2: name gets its own line on mobile, never truncated to a single char */}
                <div className="flex-1 min-w-0">
                  <div className="flex items-center gap-2 text-sm font-medium text-[#003D5B] dark:text-white min-w-0">
                    {positive ? (
                      <TrendingUp className="w-3.5 h-3.5 text-[#00798C] shrink-0" />
                    ) : (
                      <TrendingDown className="w-3.5 h-3.5 text-[#D1495B] shrink-0" />
                    )}
                    <span className="truncate">{r.name}</span>
                  </div>
                </div>
                <div className="hidden sm:block shrink-0">
                  <Sparkline data={r.months} color={palette.income} />
                </div>
                <div className="text-right shrink-0 w-32 hidden md:block">
                  <div className="text-xs text-gray-400 dark:text-text-soft uppercase tracking-wider">YTD income</div>
                  <div className="text-sm font-semibold tabular-nums text-[#003D5B] dark:text-white">
                    {ZAR2(r.income)}
                  </div>
                </div>
                <div
                  className={`shrink-0 hidden md:flex items-center gap-1 px-2.5 py-1.5 rounded-lg text-xs font-semibold ${
                    positive
                      ? "bg-[#00798C]/10 text-[#00798C] dark:bg-[#00798C]/20"
                      : "bg-[#D1495B]/10 text-[#D1495B] dark:bg-[#D1495B]/20"
                  }`}
                >
                  {positive ? "+" : ""}{ZAR(r.ytdProfit)}
                </div>
                <ChevronRight
                  className={`w-4 h-4 text-gray-400 shrink-0 transition-transform ${isOpen ? "rotate-90" : ""}`}
                />
              </div>
              {/* Row 2 (mobile only): sparkline + YTD + P/L pill */}
              <div className="flex sm:hidden items-center justify-between gap-3 pt-2 text-xs">
                {/* 72/28, not the 120/36 default: Sparkline's root is a fixed-width
                    shrink-0 box, and the pill beside it is shrink-0 too, so with
                    nothing allowed to give the pill was pushed ~32px outside the
                    card and sat on the viewport edge. /sites already passes 72 here
                    for exactly this reason. */}
                <Sparkline data={r.months} color={palette.income} width={72} height={28} />
                <div className="text-right min-w-0">
                  <div className="text-xs text-gray-400 dark:text-text-soft uppercase tracking-wider">YTD income</div>
                  <div className="text-sm font-semibold tabular-nums text-[#003D5B] dark:text-white">{ZAR2(r.income)}</div>
                </div>
                <div
                  className={`shrink-0 flex items-center gap-1 px-2.5 py-1.5 rounded-lg text-xs font-semibold ${
                    positive
                      ? "bg-[#00798C]/10 text-[#00798C] dark:bg-[#00798C]/20"
                      : "bg-[#D1495B]/10 text-[#D1495B] dark:bg-[#D1495B]/20"
                  }`}
                >
                  {positive ? "+" : ""}{ZAR(r.ytdProfit)}
                </div>
              </div>
            </button>

            {isOpen && (
              <div className="border-t border-gray-100 dark:border-border px-4 py-4 bg-gray-50/50 dark:bg-white/[0.04]">
                {/* 12-col on md+, 3-col on mobile — Part 3: unreadable at 375px otherwise */}
                <div className="grid grid-cols-3 md:grid-cols-6 lg:grid-cols-12 gap-2 text-xs">
                  {r.months.map((v, i) => (
                    <div key={i} className="text-center">
                      <div className="text-gray-400 dark:text-text-soft text-xs mb-1">{MONTH_NAMES[i]}</div>
                      <div
                        className={`py-1.5 rounded tabular-nums ${
                          (v ?? 0) > 0
                            ? "bg-[#00798C]/5 text-[#00798C] dark:bg-[#00798C]/15"
                            : "text-gray-300 dark:text-text-soft"
                        }`}
                      >
                        {v == null ? "—" : (v > 0 ? ZAR2(v) : "R 0")}
                      </div>
                    </div>
                  ))}
                </div>
                <div className="grid grid-cols-3 gap-4 mt-4 pt-3 border-t border-gray-100 dark:border-border text-xs">
                  <div>
                    <div className="text-gray-400 uppercase tracking-wider text-xs">YTD income</div>
                    <div className="font-semibold tabular-nums text-[#003D5B] dark:text-white">{ZAR(r.income)}</div>
                  </div>
                  <div>
                    <div className="text-gray-400 uppercase tracking-wider text-xs">Fixed + running</div>
                    <div className="font-semibold tabular-nums text-[#003D5B] dark:text-white">
                      {ZAR(r.fixed + r.running)}
                    </div>
                  </div>
                  <div>
                    <div className="text-gray-400 uppercase tracking-wider text-xs">Profit</div>
                    <div className={`font-semibold tabular-nums ${positive ? "text-[#00798C]" : "text-[#D1495B]"}`}>
                      {positive ? "+" : ""}{ZAR(r.ytdProfit)}
                    </div>
                  </div>
                  </div>
              </div>
            )}
          </div>
        );
      })}
    </div>
  );
}

function GridView({ rows }: { rows: IncomeRow[] }) {
  return (
    <div className="relative bg-white dark:bg-surface rounded-2xl border border-gray-100 dark:border-border shadow-sm overflow-hidden">
      <div className="overflow-x-auto" style={{ WebkitOverflowScrolling: "touch" }}>
        <table className="w-full text-sm min-w-[720px]">
          <thead>
            <tr className="text-xs text-gray-500 dark:text-gray-400 uppercase tracking-wider border-b border-gray-100 dark:border-border bg-gray-50/50 dark:bg-white/[0.04]">
              <th className="text-left py-3 px-6 font-medium sticky left-0 bg-gray-50/95 dark:bg-surface-muted/95 backdrop-blur z-10">Code</th>
              <th className="text-left py-3 px-3 font-medium">Machine</th>
              {MONTH_NAMES.map((m) => (
                <th key={m} className="text-right py-3 px-2 font-medium min-w-[78px]">{m}</th>
              ))}
              <th className="text-right py-3 px-6 font-medium">YTD</th>
            </tr>
          </thead>
          <tbody>
            {rows.map((r) => {
              const positive = r.ytdProfit >= 0;
              return (
                <tr key={r.id} className="border-b border-gray-50 dark:border-border hover:bg-gray-50/40 dark:hover:bg-white/[0.02]">
                  <td className="py-2.5 px-6 sticky left-0 bg-white dark:bg-surface">
                    <span className="font-mono text-xs px-2 py-1 rounded-md bg-[#00798C]/10 text-[#00798C] font-semibold">
                      {r.code}
                    </span>
                  </td>
                  <td className="py-2.5 px-3 font-medium text-[#003D5B] dark:text-white whitespace-nowrap">
                    <div className="flex items-center gap-2">
                      {positive ? <TrendingUp className="w-3 h-3 text-[#00798C]" /> : <TrendingDown className="w-3 h-3 text-[#D1495B]" />}
                      {r.name}
                    </div>
                  </td>
                  {r.months.map((v, i) => (
                    <td key={i} className={`py-2.5 px-2 text-right tabular-nums ${(v ?? 0) > 0 ? "text-gray-700 dark:text-gray-300" : "text-gray-300 dark:text-text-soft"}`}>
                      {v == null ? "—" : (v > 0 ? ZAR2(v) : "R 0")}
                    </td>
                  ))}
                  <td className={`py-2.5 px-6 text-right tabular-nums font-semibold whitespace-nowrap ${positive ? "text-[#00798C]" : "text-[#D1495B]"}`}>
                    <div className="inline-flex items-center gap-1.5">
                      {positive ? "+" : ""}{ZAR(r.ytdProfit)}
                    </div>
                  </td>
                </tr>
              );
            })}
          </tbody>
          {/* Totals row: the sum of every machine for each month. */}
          <tfoot>
            <tr className="border-t-2 border-gray-200 dark:border-white/15 bg-gray-50/80 dark:bg-white/[0.04]">
              <td className="py-3 px-6 sticky left-0 z-10 bg-gray-50/95 dark:bg-surface-muted/95 backdrop-blur text-sm font-semibold text-[#003D5B] dark:text-white">
                Total
              </td>
              <td className="py-3 px-3 text-sm font-semibold text-[#003D5B] dark:text-white whitespace-nowrap">
                All machines
              </td>
              {MONTH_NAMES.map((m, i) => {
                const sum = rows.reduce((s, r) => s + (r.months[i] ?? 0), 0);
                return (
                  <td
                    key={m}
                    className="py-3 px-2 text-right tabular-nums whitespace-nowrap text-gray-600 dark:text-gray-300"
                  >
                    {sum > 0 ? ZAR(sum) : "—"}
                  </td>
                );
              })}
              <td className="py-3 px-6 text-right tabular-nums font-semibold whitespace-nowrap text-[#003D5B] dark:text-white">
                {ZAR(rows.reduce((s, r) => s + r.income, 0))}
              </td>
            </tr>
          </tfoot>
        </table>
      </div>
      <ScrollFade />
    </div>
  );
}