import { useEffect, useState } from "react";
import { useTranslation } from "react-i18next";
import { useQuery } from "@tanstack/react-query";
import {
  closeShift,
  fetchEvents,
  fetchShift,
  fetchShiftReport,
  fetchShifts,
  openShift,
  type ShiftReport,
  type ShiftSummary,
  type SessionUser,
} from "./api.js";
import { formatMoney, formatDuration, formatRelativeDateTime } from "./lib/format.js";
import { CARD_PAYMENTS_ENABLED } from "./lib/features.js";
import { Modal } from "./ui/Modal.js";
import { EventDetailModal, EventRow } from "./ui/event-detail.js";
import type { LedgerEvent } from "@parking/shared";

// Shift hub — a two-pane master/detail. LEFT: the open/CURRENT shift (when any) plus
// completed shifts, filterable by a timeframe preset and (admin) by operator. RIGHT: the
// selected shift's signed activity log (every ledger event in its window). The current
// shift's pane carries the shift ACTIONS (End shift / drawer voucher / takings-so-far),
// each opening a modal. Scope is enforced SERVER-SIDE: an operator sees only their own;
// an admin (shift:cash) sees all. See wiki/concepts/shift.md.

function money(minor: number, currency: string | null): string {
  return currency ? formatMoney(minor, currency) : (minor / 100).toFixed(2);
}

type Preset = "yesterday" | "week" | "month" | "custom" | "all";

/** A preset → an inclusive [from, to] date window (yyyy-mm-dd) over the shift START. */
function presetRange(p: Preset): { from: string; to: string } | null {
  if (p === "all" || p === "custom") return null;
  const now = new Date();
  const iso = (d: Date) => d.toISOString().slice(0, 10);
  if (p === "yesterday") {
    const y = new Date(now);
    y.setDate(y.getDate() - 1);
    return { from: iso(y), to: iso(y) };
  }
  const from = new Date(now);
  from.setDate(from.getDate() - (p === "week" ? 7 : 30));
  return { from: iso(from), to: iso(now) };
}

/** The CURRENT (open) shift, synthesized from the X-report so it lists alongside closed
 *  shifts. `id` is a sentinel; `open` marks it for the badge + the action pane. null when
 *  no shift is open (or not visible to the requester). */
function useCurrentShift(): { current: (ShiftSummary & { open: true }) | null; isMine: boolean; refetch: () => void } {
  const status = useQuery({ queryKey: ["shift", "current"], queryFn: fetchShift });
  const report = useQuery({
    queryKey: ["shift", "xreport"],
    queryFn: fetchShiftReport,
    enabled: status.data?.open != null,
  });
  const refetch = () => {
    void status.refetch();
    void report.refetch();
  };
  if (!status.data?.open || !report.data) return { current: null, isMine: status.data?.isMine ?? false, refetch };
  const x = report.data;
  return {
    isMine: status.data.isMine,
    refetch,
    current: {
      id: "__current__",
      index: Number.MAX_SAFE_INTEGER,
      operator: x.operator,
      startedAt: x.startedAt,
      endedAt: x.asOf,
      cashTotalMinor: x.cashTotalMinor,
      cardTotalMinor: x.cardTotalMinor,
      currency: x.currency,
      paymentCount: x.paymentCount,
      ticketTotalMinor: x.ticketTotalMinor,
      subscriptionTotalMinor: x.subscriptionTotalMinor,
      subscriptionSalesMinor: x.subscriptionSalesMinor,
      subscriptionWindowMinor: x.subscriptionWindowMinor,
      openingFloatMinor: x.openingFloatMinor,
      cashAddedMinor: x.cashAddedMinor,
      cashRemovedMinor: x.cashRemovedMinor,
      expectedDrawerMinor: x.expectedDrawerMinor,
      open: true,
    },
  };
}

export function ShiftsHistory({ user, canManage = false }: { user: SessionUser | null; canManage?: boolean }) {
  const { t } = useTranslation();
  const [preset, setPreset] = useState<Preset>("week");
  const [operator, setOperator] = useState("");
  const [customFrom, setCustomFrom] = useState("");
  const [customTo, setCustomTo] = useState("");
  const [selectedId, setSelectedId] = useState<string | null>(null);

  const { current, isMine, refetch: refetchCurrent } = useCurrentShift();

  const range = preset === "custom" ? { from: customFrom, to: customTo } : presetRange(preset);
  const applied = {
    operator: operator.trim() || undefined,
    from: range?.from ? new Date(`${range.from}T00:00:00`).toISOString() : undefined,
    to: range?.to ? new Date(`${range.to}T23:59:59`).toISOString() : undefined,
  };

  const q = useQuery({ queryKey: ["shifts", applied], queryFn: () => fetchShifts(applied) });
  const isAdmin = q.data?.scope === "all";
  const closed = q.data?.shifts ?? [];

  // The current/open shift sits at the TOP of the list (when present + visible to me).
  const list: (ShiftSummary & { open?: boolean })[] = current && (isMine || isAdmin) ? [current, ...closed] : closed;
  const selected = list.find((s) => s.id === selectedId) ?? list[0] ?? null;

  // Default the selection to the current shift (if any), else the newest closed one.
  useEffect(() => {
    if (list.length === 0) setSelectedId(null);
    else if (!list.some((s) => s.id === selectedId)) setSelectedId(list[0]!.id);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [q.data, current?.id]);

  function refreshAll() {
    void q.refetch();
    refetchCurrent();
  }

  const PRESETS: Preset[] = ["yesterday", "week", "month", "all", "custom"];

  // Fill the viewport like the booth: a fixed title + filters, then a two-pane area
  // that takes the remaining height — the shift LIST and the activity LOG each scroll
  // on their own rather than the whole page growing.
  return (
    <div className="flex h-full min-h-0 flex-col">
      <div className="mb-3 flex shrink-0 flex-wrap items-center justify-between gap-2">
        <h1 className="text-sm font-bold uppercase tracking-widest text-term-amber">
          {isAdmin ? t("shifts.title") : t("shifts.myTitle")}
        </h1>
        {/* No shift open → the only action is to start one (gated on shift:create). */}
        {canManage && !current && (
          <StartShiftButton onDone={refreshAll} />
        )}
      </div>

      {/* Filters: timeframe presets (everyone) + operator (admin only). */}
      <div className="card mb-3 flex shrink-0 flex-wrap items-end gap-3 p-3">
        <div className="field">
          <span className="label">{t("shifts.timeframe")}</span>
          <div className="flex flex-wrap gap-1">
            {PRESETS.map((p) => (
              <button key={p} type="button" className={`btn btn-sm ${preset === p ? "btn-primary" : ""}`} onClick={() => setPreset(p)}>
                {t(`shifts.preset_${p}`)}
              </button>
            ))}
          </div>
        </div>
        {preset === "custom" && (
          <>
            <div className="field">
              <span className="label">{t("shifts.filterFrom")}</span>
              <input type="date" className="input w-40" value={customFrom} onChange={(e) => setCustomFrom(e.target.value)} />
            </div>
            <div className="field">
              <span className="label">{t("shifts.filterTo")}</span>
              <input type="date" className="input w-40" value={customTo} onChange={(e) => setCustomTo(e.target.value)} />
            </div>
          </>
        )}
        {isAdmin && (
          <div className="field">
            <span className="label">{t("shifts.operator")}</span>
            <input className="input w-44" value={operator} onChange={(e) => setOperator(e.target.value)} placeholder={t("shifts.allOperators")} />
          </div>
        )}
      </div>

      {q.isError && (
        <div className="mb-2 shrink-0 rounded-term border border-term-red px-3 py-2 text-[0.75rem] text-term-red">{t("shifts.loadFailed")}</div>
      )}

      {/* Two-pane: shift list (left) + selected shift's activity log (right). Both
          panes scroll independently and fill the remaining height (like the booth). */}
      <div className="grid min-h-0 flex-1 gap-3 md:grid-cols-[minmax(0,1fr)_minmax(0,1.6fr)]">
        <div className="flex min-h-0 flex-col gap-1.5 overflow-y-auto pr-1">
          {!q.isLoading && list.length === 0 && (
            <p className="rounded-term border border-term-border px-3 py-3 text-[0.75rem] text-term-muted">{t("shifts.none")}</p>
          )}
          {list.map((s) => (
            <ShiftCard key={s.id} s={s} showOperator={isAdmin} open={!!s.open} selected={selected?.id === s.id} onClick={() => setSelectedId(s.id)} />
          ))}
        </div>

        <div className="min-h-0 overflow-hidden rounded-term border border-term-border">
          {selected ? (
            <ShiftActivityLog
              shift={selected}
              isCurrent={!!selected.open}
              isMine={isMine}
              showOperator={isAdmin}
              canManage={canManage}
              onChanged={refreshAll}
            />
          ) : (
            <p className="px-3 py-6 text-center text-[0.75rem] text-term-muted">{t("shifts.selectAShift")}</p>
          )}
        </div>
      </div>
    </div>
  );
}

function StartShiftButton({ onDone }: { onDone: () => void }) {
  const { t } = useTranslation();
  const [busy, setBusy] = useState(false);
  const [err, setErr] = useState<string | null>(null);
  async function start() {
    setBusy(true);
    setErr(null);
    try {
      await openShift();
      onDone();
    } catch (e) {
      setErr((e as Error).message);
    } finally {
      setBusy(false);
    }
  }
  return (
    <span className="flex items-center gap-2">
      {err && <span className="text-[0.75rem] text-term-red">{err}</span>}
      <button type="button" className="btn btn-go btn-sm" onClick={start} disabled={busy}>
        {busy ? t("shift.starting") : t("shift.startShift")}
      </button>
    </span>
  );
}

function ShiftCard({ s, showOperator, open, selected, onClick }: { s: ShiftSummary; showOperator: boolean; open: boolean; selected: boolean; onClick: () => void }) {
  const { t } = useTranslation();
  const cur = s.currency;
  const when = (iso: string) => formatRelativeDateTime(iso, t);
  return (
    <button
      type="button"
      onClick={onClick}
      className={`card w-full p-2.5 text-left text-[0.75rem] transition-colors ${selected ? "border-term-amber bg-term-panel-2" : "hover:bg-term-panel-2"}`}
    >
      <div className="flex items-center justify-between gap-2">
        <span className="flex items-center gap-2 font-semibold text-term-text">
          {open && <span className="rounded border border-term-green px-1 text-[0.625rem] text-term-green">{t("shifts.current")}</span>}
          {showOperator ? s.operator : when(s.startedAt)}
        </span>
        <span className="text-term-muted">{formatDuration(s.startedAt, s.endedAt)}</span>
      </div>
      {showOperator && <div className="text-term-muted">{when(s.startedAt)}</div>}
      <div className="mt-1 flex flex-wrap gap-x-3 tabular-nums">
        <span className="text-term-muted">{t("shifts.payments")} {s.paymentCount}</span>
        <span className="text-term-green">{money(s.cashTotalMinor, cur)}</span>
        {CARD_PAYMENTS_ENABLED && <span className="text-term-cyan">{money(s.cardTotalMinor, cur)}</span>}
        <span className="ml-auto font-semibold text-term-text" title={t("shifts.expectedDrawer")}>{money(s.expectedDrawerMinor, cur)}</span>
      </div>
    </button>
  );
}

function ShiftActivityLog({
  shift,
  isCurrent,
  isMine,
  showOperator,
  canManage,
  onChanged,
}: {
  shift: ShiftSummary;
  isCurrent: boolean;
  isMine: boolean;
  showOperator: boolean;
  canManage: boolean;
  onChanged: () => void;
}) {
  const { t } = useTranslation();
  const [modal, setModal] = useState<null | "end" | "takings">(null);
  // Click an activity row → the SAME read-only event-detail modal the booth feed opens
  // (full signed payload + snapshots + chain provenance).
  const [detailEvent, setDetailEvent] = useState<LedgerEvent | null>(null);

  // The current shift's log runs entry→now (no upper bound); a closed shift is bounded.
  const q = useQuery({
    queryKey: ["shift-events", shift.id, shift.endedAt],
    queryFn: () => fetchEvents(1000, shift.startedAt, isCurrent ? undefined : shift.endedAt),
    refetchInterval: isCurrent ? 5000 : false,
  });
  const events = q.data?.events ?? [];
  const cur = shift.currency;

  // Fill the pane: a fixed header + a scrollable activity list (matches the booth feed).
  return (
    <div className="flex h-full min-h-0 flex-col">
      <div className="shrink-0 border-b border-term-border bg-term-panel-2 px-3 py-2">
        <div className="flex flex-wrap items-center justify-between gap-2 text-[0.75rem]">
          <span className="flex items-center gap-2 font-semibold text-term-text">
            {isCurrent && <span className="rounded border border-term-green px-1 text-[0.625rem] text-term-green">{t("shifts.current")}</span>}
            {showOperator && `${shift.operator} · `}
            {formatRelativeDateTime(shift.startedAt, t)}
            {!isCurrent && ` → ${formatRelativeDateTime(shift.endedAt, t)}`}
          </span>
          {/* Actions live on the CURRENT shift's pane (when it's mine), each → a modal. */}
          {isCurrent && isMine && canManage && (
            <span className="flex flex-wrap gap-1.5">
              <button type="button" className="btn btn-sm" onClick={() => setModal("takings")}>{t("shift.viewTakings")}</button>
              <button type="button" className="btn btn-sm btn-danger" onClick={() => setModal("end")}>{t("shift.endShift")}</button>
            </span>
          )}
        </div>
        <div className="mt-1 grid grid-cols-2 gap-x-6 gap-y-0.5 text-[0.6875rem] tabular-nums sm:grid-cols-4">
          <Figure label={t("shifts.srcTickets")} value={money(shift.ticketTotalMinor, cur)} />
          <Figure label={t("shifts.srcSubscriptions")} value={money(shift.subscriptionTotalMinor, cur)} />
          {/* Abonime is the subscription TOTAL; only the out-of-window part is broken out. */}
          <Figure label={t("shifts.srcSubWindow")} value={money(shift.subscriptionWindowMinor, cur)} sub />
          <Figure label={t("shifts.openingFloat")} value={money(shift.openingFloatMinor, cur)} />
          <Figure label={t("shifts.cashTaken")} value={money(shift.cashTotalMinor, cur)} />
          <Figure label={t("shifts.cashAdded")} value={money(shift.cashAddedMinor, cur)} />
          <Figure label={t("shifts.cashRemoved")} value={money(shift.cashRemovedMinor, cur)} />
          {CARD_PAYMENTS_ENABLED && <Figure label={t("shifts.card")} value={money(shift.cardTotalMinor, cur)} />}
          <Figure label={t("shifts.expectedDrawer")} value={money(shift.expectedDrawerMinor, cur)} bold />
        </div>
      </div>

      <div className="min-h-0 flex-1 overflow-y-auto px-1">
        {q.isLoading && <p className="px-3 py-3 text-[0.75rem] text-term-muted">{t("common.loading")}</p>}
        {!q.isLoading && events.length === 0 && <p className="px-3 py-3 text-[0.75rem] text-term-muted">{t("shifts.noActivity")}</p>}
        {events.map((e) => (
          <EventRow key={e.id} e={e} onOpen={setDetailEvent} />
        ))}
      </div>

      {detailEvent && <EventDetailModal e={detailEvent} onClose={() => setDetailEvent(null)} />}
      {modal === "end" && <EndShiftModal shift={shift} onClose={() => setModal(null)} onDone={onChanged} />}
      {modal === "takings" && <TakingsModal onClose={() => setModal(null)} />}
    </div>
  );
}

// --- Action modals ---------------------------------------------------------

function EndShiftModal({ shift, onClose, onDone }: { shift: ShiftSummary; onClose: () => void; onDone: () => void }) {
  const { t } = useTranslation();
  const [busy, setBusy] = useState(false);
  const [report, setReport] = useState<ShiftReport | null>(null);
  const [err, setErr] = useState<string | null>(null);
  const cur = shift.currency;

  async function confirm() {
    setBusy(true);
    setErr(null);
    try {
      setReport(await closeShift());
      onDone();
    } catch (e) {
      setErr((e as Error).message);
    } finally {
      setBusy(false);
    }
  }

  return (
    <Modal open onClose={onClose} title={t("shift.endShift")} width="max-w-md">
      {report ? (
        // Result — the signed Z-report.
        <div className="text-[0.8125rem] tabular-nums">
          <div className="font-semibold text-term-text">{t("shift.zReport")} — {report.operator}</div>
          <div className="mt-1 grid grid-cols-2 gap-x-6 gap-y-0.5">
            <Figure label={t("shift.payments")} value={String(report.paymentCount)} />
            <span />
            <Figure label={t("shift.srcTickets")} value={money(report.ticketTotalMinor, report.currency)} />
            <Figure label={t("shift.srcSubscriptions")} value={money(report.subscriptionTotalMinor, report.currency)} />
            {/* Abonime is the subscription TOTAL; only the out-of-window part is broken out. */}
            <span />
            <Figure label={t("shift.srcSubWindow")} value={money(report.subscriptionWindowMinor, report.currency)} sub />
          </div>
          <div className="mt-1 grid grid-cols-2 gap-x-6 gap-y-0.5 border-t border-term-border pt-1">
            <Figure label={t("shift.cash")} value={money(report.cashTotalMinor, report.currency)} />
            {CARD_PAYMENTS_ENABLED && <Figure label={t("shift.card")} value={money(report.cardTotalMinor, report.currency)} />}
            <Figure label={t("shift.openingFloat")} value={money(report.openingFloatMinor, report.currency)} />
            <Figure label={t("shift.cashAdded")} value={money(report.cashAddedMinor, report.currency)} />
            <Figure label={t("shift.cashRemoved")} value={money(report.cashRemovedMinor, report.currency)} />
            <Figure label={t("shift.expectedDrawer")} value={money(report.expectedDrawerMinor, report.currency)} bold />
          </div>
          <div className={report.printed ? "mt-2 text-term-green" : "mt-2 text-term-amber"}>
            {report.printed ? t("shift.printedToReceipt") : t("shift.recordedNoPrinter")}
          </div>
          <div className="mt-3 flex justify-end">
            <button type="button" className="btn btn-sm" onClick={onClose}>{t("common.close")}</button>
          </div>
        </div>
      ) : (
        // Confirm — show the live takings (split by source) + drawer before closing.
        <div className="text-[0.8125rem] tabular-nums">
          <p className="text-term-muted">{t("shift.endConfirm")}</p>
          <div className="mt-2 grid grid-cols-2 gap-x-6 gap-y-0.5">
            <Figure label={t("shift.srcTickets")} value={money(shift.ticketTotalMinor, cur)} />
            <Figure label={t("shift.srcSubscriptions")} value={money(shift.subscriptionTotalMinor, cur)} />
            {/* Abonime is the subscription TOTAL; only the out-of-window part is broken out. */}
            <span />
            <Figure label={t("shift.srcSubWindow")} value={money(shift.subscriptionWindowMinor, cur)} sub />
          </div>
          <div className="mt-2 grid grid-cols-2 gap-x-6 gap-y-0.5 border-t border-term-border pt-2">
            <Figure label={t("shift.cash")} value={money(shift.cashTotalMinor, cur)} />
            {CARD_PAYMENTS_ENABLED && <Figure label={t("shift.card")} value={money(shift.cardTotalMinor, cur)} />}
            {/* Drawer math made explicit: opening cash + cash taken = expected drawer. */}
            <Figure label={t("shift.openingFloat")} value={money(shift.openingFloatMinor, cur)} />
            <span />
            <Figure label={t("shift.expectedDrawer")} value={money(shift.expectedDrawerMinor, cur)} bold />
          </div>
          {err && <p className="mt-2 text-[0.75rem] text-term-red">{err}</p>}
          <div className="mt-3 flex justify-end gap-2">
            <button type="button" className="btn btn-sm" onClick={onClose}>{t("subs.cancel")}</button>
            <button type="button" className="btn btn-sm btn-danger" onClick={confirm} disabled={busy}>
              {busy ? t("shift.ending") : t("shift.endShift")}
            </button>
          </div>
        </div>
      )}
    </Modal>
  );
}

function TakingsModal({ onClose }: { onClose: () => void }) {
  const { t } = useTranslation();
  const q = useQuery({ queryKey: ["shift", "xreport", "modal"], queryFn: fetchShiftReport });
  const x = q.data;
  return (
    <Modal open onClose={onClose} title={t("shift.xReport")} width="max-w-md">
      {!x ? (
        <p className="text-[0.75rem] text-term-muted">{t("common.loading")}</p>
      ) : (
        <div className="text-[0.8125rem] tabular-nums">
          <div className="text-term-muted">{t("shift.asOf")} {new Date(x.asOf).toLocaleString()}</div>
          <div className="mt-1 grid grid-cols-2 gap-x-6 gap-y-0.5">
            <Figure label={t("shift.payments")} value={String(x.paymentCount)} />
            <span />
            <Figure label={t("shift.srcTickets")} value={money(x.ticketTotalMinor, x.currency)} />
            <Figure label={t("shift.srcSubscriptions")} value={money(x.subscriptionTotalMinor, x.currency)} />
            {/* Abonime is the subscription TOTAL; only the out-of-window part is broken out. */}
            <span />
            <Figure label={t("shift.srcSubWindow")} value={money(x.subscriptionWindowMinor, x.currency)} sub />
          </div>
          <div className="mt-1 grid grid-cols-2 gap-x-6 gap-y-0.5 border-t border-term-border pt-1">
            <Figure label={t("shift.cash")} value={money(x.cashTotalMinor, x.currency)} />
            {CARD_PAYMENTS_ENABLED && <Figure label={t("shift.card")} value={money(x.cardTotalMinor, x.currency)} />}
            <Figure label={t("shift.openingFloat")} value={money(x.openingFloatMinor, x.currency)} />
            <Figure label={t("shift.cashAdded")} value={money(x.cashAddedMinor, x.currency)} />
            <Figure label={t("shift.cashRemoved")} value={money(x.cashRemovedMinor, x.currency)} />
            <Figure label={t("shift.expectedDrawer")} value={money(x.expectedDrawerMinor, x.currency)} bold />
          </div>
          <div className="mt-2 text-[0.6875rem] text-term-muted">{t("shift.xReportHint")}</div>
          <div className="mt-3 flex justify-end">
            <button type="button" className="btn btn-sm" onClick={onClose}>{t("common.close")}</button>
          </div>
        </div>
      )}
    </Modal>
  );
}

function Figure({ label, value, bold, sub }: { label: string; value: string; bold?: boolean; sub?: boolean }) {
  return (
    <div className={`flex justify-between gap-2 ${sub ? "pl-3" : ""}`}>
      <span className={`whitespace-nowrap ${sub ? "text-term-muted/70" : "text-term-muted"}`}>{label}</span>
      {/* The money/number never splits across lines (e.g. "89,650 ALL"). */}
      <span className={`whitespace-nowrap ${bold ? "font-semibold text-term-text" : "text-term-text"}`}>{value}</span>
    </div>
  );
}