import { useState } from "react";
import { useTranslation } from "react-i18next";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import {
  fetchDrawerMovements,
  recordDrawerMovement,
  reviewDrawerMovement,
  type DrawerMovement,
  type MovementStatus,
} from "./api.js";
import { formatMoney, formatRelativeDateTime } from "./lib/format.js";
import { Panel } from "./ui/Panel.js";

// Drawer cash movements. Operators RECORD receipts (Mandat Arkëtimi / cash_in) and
// disbursements (Mandat Pagese / cash_out) freely; admins REVIEW them after the fact
// (authorize/deny — a flag, never a cash reversal). A denial is a judgment about the
// operator, settled outside the app: the drawer balance is untouched. See
// wiki/concepts/shift.md.

const money = (m: number, cur: string | null) => formatMoney(m, cur ?? "");

function StatusBadge({ status }: { status: MovementStatus }) {
  const { t } = useTranslation();
  const cls =
    status === "authorized"
      ? "border-term-green/60 text-term-green"
      : status === "denied"
        ? "border-term-red/60 text-term-red"
        : "border-term-amber/60 text-term-amber";
  return (
    <span className={`rounded border px-1 text-[0.625rem] uppercase tracking-wider ${cls}`}>
      {t(`drawer.status.${status}`)}
    </span>
  );
}

export function DrawerManager({ canCreate, canReview }: { canCreate: boolean; canReview: boolean }) {
  const { t } = useTranslation();
  const qc = useQueryClient();
  // Reviewers can filter the list (the pending queue); operators always see their own, all.
  const [statusFilter, setStatusFilter] = useState<MovementStatus | "">("");
  const q = useQuery({
    queryKey: ["drawer", "movements", canReview ? statusFilter : ""],
    queryFn: () => fetchDrawerMovements(canReview && statusFilter ? statusFilter : undefined),
  });
  const movements = q.data?.movements ?? [];
  const pendingCount = movements.filter((m) => m.status === "pending").length;

  return (
    <div className="flex h-full flex-col gap-3 p-3">
      {canCreate && <RecordPanel onDone={() => void qc.invalidateQueries({ queryKey: ["drawer"] })} />}

      <Panel
        title={canReview ? t("drawer.allTitle") : t("drawer.myTitle")}
        right={
          canReview && pendingCount > 0 ? (
            <span className="rounded border border-term-amber/60 px-1.5 text-[0.625rem] uppercase tracking-wider text-term-amber">
              {t("drawer.pendingCount", { count: pendingCount })}
            </span>
          ) : null
        }
        className="min-h-0 flex-1"
      >
        <div className="flex h-full flex-col">
          {canReview && (
            <div className="mb-2 flex items-center gap-1.5">
              {(["", "pending", "authorized", "denied"] as const).map((s) => (
                <button
                  key={s || "all"}
                  type="button"
                  onClick={() => setStatusFilter(s)}
                  className={statusFilter === s ? "btn btn-primary btn-sm" : "btn btn-sm"}
                >
                  {s === "" ? t("drawer.filterAll") : t(`drawer.status.${s}`)}
                </button>
              ))}
            </div>
          )}

          <div className="min-h-0 flex-1 overflow-y-auto pr-1">
            {q.isLoading ? (
              <div className="text-term-muted">{t("common.loading")}</div>
            ) : movements.length === 0 ? (
              <div className="text-term-muted">{t("drawer.empty")}</div>
            ) : (
              <table className="w-full text-[0.75rem] tabular-nums">
                <thead className="sticky top-0 bg-term-panel-2 text-[0.6875rem] uppercase tracking-wider text-term-muted">
                  <tr>
                    <th className="px-2 py-1.5 text-left font-semibold">{t("drawer.colWhen")}</th>
                    <th className="px-2 py-1.5 text-left font-semibold">{t("drawer.colType")}</th>
                    <th className="px-2 py-1.5 text-right font-semibold">{t("drawer.colAmount")}</th>
                    <th className="px-2 py-1.5 text-left font-semibold">{t("drawer.colReason")}</th>
                    {canReview && <th className="px-2 py-1.5 text-left font-semibold">{t("drawer.colOperator")}</th>}
                    <th className="px-2 py-1.5 text-left font-semibold">{t("drawer.colStatus")}</th>
                    {canReview && <th className="px-2 py-1.5" />}
                  </tr>
                </thead>
                <tbody>
                  {movements.map((m) => (
                    <MovementRow key={m.id} m={m} canReview={canReview} onReviewed={() => void qc.invalidateQueries({ queryKey: ["drawer"] })} />
                  ))}
                </tbody>
              </table>
            )}
          </div>
        </div>
      </Panel>
    </div>
  );
}

function RecordPanel({ onDone }: { onDone: () => void }) {
  const { t } = useTranslation();
  const [amount, setAmount] = useState("");
  const [reason, setReason] = useState("");
  const [msg, setMsg] = useState<{ text: string; ok: boolean } | null>(null);
  const record = useMutation({
    mutationFn: (type: "cash_in" | "cash_out") =>
      recordDrawerMovement({ type, amountMinor: Math.round(Number(amount) * 100), reason: reason.trim() }),
    onSuccess: (r) => {
      setMsg({ ok: true, text: t("drawer.recorded", { no: r.voucherNo, amount: money(r.balanceMinor, null) }) });
      setAmount("");
      setReason("");
      onDone();
    },
    onError: (e) => setMsg({ ok: false, text: (e as Error).message }),
  });

  function submit(type: "cash_in" | "cash_out") {
    setMsg(null);
    const major = Number(amount);
    if (!Number.isFinite(major) || major <= 0) {
      setMsg({ ok: false, text: t("drawer.enterPositive") });
      return;
    }
    record.mutate(type);
  }

  return (
    <Panel title={t("drawer.recordTitle")}>
      <div className="flex flex-col gap-2 text-[0.8125rem]">
        <div className="flex flex-wrap items-center gap-2">
          <input
            className="input w-28"
            value={amount}
            onChange={(e) => setAmount(e.target.value)}
            placeholder={t("drawer.amount")}
            inputMode="decimal"
          />
          <input
            className="input min-w-40 flex-1"
            value={reason}
            onChange={(e) => setReason(e.target.value)}
            placeholder={t("drawer.reasonPlaceholder")}
          />
        </div>
        <div className="text-[0.6875rem] text-term-muted">{t("drawer.recordHint")}</div>
        {msg && (
          <div className={`text-[0.75rem] ${msg.ok ? "text-term-green" : "text-term-red"}`}>{msg.text}</div>
        )}
        <div className="flex justify-end gap-2">
          <button type="button" className="btn btn-go btn-sm" disabled={record.isPending} onClick={() => submit("cash_in")}>
            {t("drawer.mandatArketimi")}
          </button>
          <button type="button" className="btn btn-danger btn-sm" disabled={record.isPending} onClick={() => submit("cash_out")}>
            {t("drawer.mandatPagese")}
          </button>
        </div>
      </div>
    </Panel>
  );
}

function MovementRow({ m, canReview, onReviewed }: { m: DrawerMovement; canReview: boolean; onReviewed: () => void }) {
  const { t } = useTranslation();
  const [note, setNote] = useState("");
  const [noteOpen, setNoteOpen] = useState(false);
  const review = useMutation({
    mutationFn: (decision: "authorize" | "deny") =>
      reviewDrawerMovement({ refId: m.id, decision, note: note.trim() || undefined }),
    onSuccess: onReviewed,
  });
  // Direction sign for display: cash_in is +, cash_out is −.
  const signed = m.type === "cash_in" ? m.amountMinor : -m.amountMinor;
  return (
    <tr className="border-t border-term-border/50 align-top">
      <td className="whitespace-nowrap px-2 py-1.5 text-term-muted">{formatRelativeDateTime(m.at, t)}</td>
      <td className="px-2 py-1.5">
        <span className={m.type === "cash_in" ? "text-term-green" : "text-term-red"}>
          {m.type === "cash_in" ? t("drawer.mandatArketimi") : t("drawer.mandatPagese")}
        </span>
        {m.voucherNo && <span className="ml-1 text-[0.625rem] text-term-muted">{m.voucherNo}</span>}
      </td>
      <td className={`whitespace-nowrap px-2 py-1.5 text-right ${signed < 0 ? "text-term-red" : "text-term-green"}`}>
        {money(signed, m.currency)}
      </td>
      <td className="px-2 py-1.5 text-term-text">{m.reason || "—"}</td>
      {canReview && <td className="px-2 py-1.5 text-term-muted">{m.operator}</td>}
      <td className="px-2 py-1.5">
        <StatusBadge status={m.status} />
        {m.status !== "pending" && m.reviewedBy && (
          <div className="mt-0.5 text-[0.5625rem] text-term-muted">
            {m.reviewedBy}
            {m.reviewNote ? ` · ${m.reviewNote}` : ""}
          </div>
        )}
      </td>
      {canReview && (
        <td className="px-2 py-1.5 text-right">
          {m.status === "pending" ? (
            <div className="flex flex-col items-end gap-1">
              <div className="flex gap-1">
                <button type="button" className="btn btn-go btn-sm" disabled={review.isPending} onClick={() => review.mutate("authorize")}>
                  {t("drawer.authorize")}
                </button>
                <button
                  type="button"
                  className="btn btn-danger btn-sm"
                  disabled={review.isPending}
                  onClick={() => (noteOpen ? review.mutate("deny") : setNoteOpen(true))}
                >
                  {t("drawer.deny")}
                </button>
              </div>
              {noteOpen && (
                <input
                  className="input w-44 text-[0.6875rem]"
                  value={note}
                  onChange={(e) => setNote(e.target.value)}
                  placeholder={t("drawer.denyNotePlaceholder")}
                />
              )}
              {review.isError && <span className="text-[0.625rem] text-term-red">{(review.error as Error).message}</span>}
            </div>
          ) : null}
        </td>
      )}
    </tr>
  );
}