import { useRef, useState, type ReactNode } from "react";
import { useTranslation } from "react-i18next";
import { useQuery } from "@tanstack/react-query";
import { fetchEvents, fetchOccupancy, type LedgerEvent, type Occupancy } from "./api.js";
import { formatMoney } from "./lib/format.js";
import { qk } from "./lib/query.js";
import { useLiveStore } from "./lib/live-store.js";
import { useShift } from "./lib/use-shift.js";
import { Panel } from "./ui/Panel.js";
import { StatusDot } from "./ui/StatusDot.js";
import { BoothPayModal } from "./BoothPayModal.js";
import { ActiveSessions } from "./ActiveSessions.js";
import { Modal } from "./ui/Modal.js";
import { SnapshotStrip } from "./ui/SnapshotStrip.js";
import { FilterBar, SegGroup, type SegOption } from "./ui/FilterBar.js";
import { renderReason } from "./lib/reason.js";

// The live operator booth view — the real-time heart of the console. Occupancy
// gauge + a streaming entry/exit/payment ticker. Query owns the initial load and
// the authoritative numbers; the WS-fed live store overlays real-time updates so
// the screen reacts the instant a car enters or exits. Dense, dark, glanceable.

/** Per-event-type display: i18n label key + accent colour for the ticker. */
const EVENT_STYLE: Record<string, { labelKey: string; color: string }> = {
  vehicle_entry: { labelKey: "booth.evtEntry", color: "text-term-green" },
  vehicle_exit: { labelKey: "booth.evtExit", color: "text-term-red" },
  payment: { labelKey: "booth.evtPay", color: "text-term-cyan" },
  void: { labelKey: "booth.evtVoid", color: "text-term-amber" },
  barrier_open_command: { labelKey: "booth.evtOpenCmd", color: "text-term-muted" },
  barrier_open_observed: { labelKey: "booth.evtOpenObserved", color: "text-term-muted" },
  shift_open: { labelKey: "booth.evtShiftOpen", color: "text-term-amber" },
  shift_z_report: { labelKey: "booth.evtShiftZ", color: "text-term-amber" },
  cash_movement: { labelKey: "booth.evtCashMovement", color: "text-term-cyan" },
  cash_in: { labelKey: "booth.evtCashIn", color: "text-term-green" },
  cash_out: { labelKey: "booth.evtCashOut", color: "text-term-amber" },
  anomaly: { labelKey: "booth.evtAnomaly", color: "text-term-red" },
};

// Live-feed filter category for an event type. Several ledger types collapse into a
// few operator-meaningful buckets; the rest (barrier/shift/cash) fall outside the
// filter and only show under "all".
type FeedCat = "entry" | "exit" | "pay" | "void" | "anomaly";
function feedCat(type: string): FeedCat | null {
  switch (type) {
    case "vehicle_entry":
      return "entry";
    case "vehicle_exit":
      return "exit";
    case "payment":
      return "pay";
    case "void":
      return "void";
    case "anomaly":
      return "anomaly";
    default:
      return null;
  }
}

function hhmmss(iso: string): string {
  // Local time-of-day, terminal style. Defensive against a bad timestamp.
  const d = new Date(iso);
  return Number.isNaN(d.getTime()) ? "--:--:--" : d.toTimeString().slice(0, 8);
}

function OccupancyGauge({ occ }: { occ: Occupancy }) {
  const { t } = useTranslation();
  const pct = occ.capacity ? Math.min(100, Math.round((occ.count / occ.capacity) * 100)) : null;
  const barColor = occ.full ? "bg-term-red" : pct != null && pct >= 85 ? "bg-term-amber" : "bg-term-green";
  return (
    <div className="flex flex-col gap-3">
      <div className="flex items-end gap-4">
        <div className="text-6xl font-bold leading-none tabular-nums text-term-text">{occ.count}</div>
        <div className="pb-1 text-term-muted">
          <div className="text-[11px] uppercase tracking-wider">{t("booth.inside")}</div>
          <div className="text-sm tabular-nums">
            {occ.capacity == null ? t("booth.uncapped") : `${t("booth.of")} ${occ.capacity}`}
          </div>
        </div>
        <div className="ml-auto text-right">
          <div className="text-[11px] uppercase tracking-wider text-term-muted">{t("booth.free")}</div>
          <div className={`text-3xl font-bold tabular-nums ${occ.full ? "text-term-red" : "text-term-green"}`}>
            {occ.free == null ? "∞" : occ.free}
          </div>
        </div>
      </div>
      {pct != null && (
        <div className="h-2 w-full overflow-hidden rounded-term bg-term-panel-2">
          <div className={`h-full ${barColor} transition-[width] duration-300`} style={{ width: `${pct}%` }} />
        </div>
      )}
      {occ.full && (
        <div className="rounded-term border border-term-red px-2 py-1 text-center text-[11px] font-bold uppercase tracking-widest text-term-red">
          {t("booth.lotFull")}
        </div>
      )}
    </div>
  );
}

/** Translated classification badges derived from a payload's boolean flags. Unlike
 *  `reason` (an immutable English sentence baked into the signed ledger, shown
 *  verbatim), these are computed client-side so they CAN be localized. They give a
 *  glanceable "what kind of anomaly" tag without parsing the free-text reason. */
function eventBadges(p: LedgerEvent["payload"]): string[] {
  if (!p) return [];
  const keys: string[] = [];
  if (p.entryRefused) keys.push("booth.badgeEntryRefused");
  if (p.exitRefused) keys.push("booth.badgeExitRefused");
  if (p.full) keys.push("booth.badgeLotFull");
  if (p.exitOpenFailed) keys.push("booth.badgeBarrierFailed");
  if (p.permitRefused) keys.push("booth.badgeSubRefused");
  if (p.ticketPrinted === false) keys.push("booth.badgeNoTicket");
  if (p.subscriptionSale) keys.push("booth.badgeSubSale");
  // Subscriber entered/exited outside their plan's allowed window → owes a deferred
  // transient charge, collected (gated) at exit. Flag it so the operator KNOWS now.
  if (typeof p.windowOwedMinor === "number" && p.windowOwedMinor > 0) keys.push("booth.badgeWindowCharge");
  if (p.source === "manual" && !p.subscriptionSale) keys.push("booth.badgeManualOpen");
  return keys;
}

/** The i18n key for a subscriber's access medium (`via`), or null. Lets the activity
 *  log show HOW a subscriber entered/left — QR code, RFID card/chip, or plate. */
function viaKey(p: LedgerEvent["payload"]): string | null {
  if (!p) return null;
  if (p.via === "qr") return "booth.viaQr";
  if (p.via === "card") return "booth.viaCard";
  if (p.via === "plate") return "booth.viaPlate";
  return null;
}

/** A short money summary for payment events (e.g. "350.00 ALL"). */
function paymentSummary(p: LedgerEvent["payload"]): string | null {
  if (!p || typeof p.amountMinor !== "number" || !p.currency) return null;
  return formatMoney(p.amountMinor, p.currency);
}

/** What to SHOW for an event's actor. A subscription occurrence has an opaque
 *  `SUBSESS-…` identity; the server resolves the holder's name into `subscriberLabel`,
 *  so we show that (e.g. "Aqif Kopertoni") instead. Otherwise the identity itself. */
function displayIdentity(e: LedgerEvent): string {
  return e.subscriberLabel ?? e.identity ?? "—";
}

function EventRow({ e, onOpen }: { e: LedgerEvent; onOpen: (e: LedgerEvent) => void }) {
  const { t } = useTranslation();
  const style = EVENT_STYLE[e.type];
  const label = style ? t(style.labelKey) : e.type.toUpperCase();
  const isAnomaly = e.type === "anomaly";
  const p = e.payload;
  // Localize the reason from the signed reasonCode (falls back to the English text on
  // legacy events). Anomalies ALWAYS get a detail line so a red flag is never silent.
  const reason = renderReason(p, t);
  const amount = paymentSummary(p);
  const badges = eventBadges(p);
  const via = viaKey(p);
  const detail = reason ?? amount ?? (isAnomaly ? t("booth.evtNoReason") : null);
  const showDetail = detail != null || badges.length > 0 || via != null;

  // The whole row is a button → opens the event-detail modal (full payload + the
  // session's entry/exit snapshots). A grid keeps the time/label/identity/index
  // columns aligned across rows; the detail line lives in its own row, indented to
  // start under the identity column so it never collides with the ticket code.
  return (
    <button
      type="button"
      onClick={() => onOpen(e)}
      className={`grid w-full grid-cols-[auto_5rem_1fr_auto] items-center gap-x-3 gap-y-0.5 border-b border-term-border/50 px-1 py-1 text-left text-[12px] tabular-nums hover:bg-term-panel-2 ${
        isAnomaly ? "bg-term-red/5" : ""
      }`}
    >
      <span className="text-term-muted">{hhmmss(e.occurredAt)}</span>
      <span className={`shrink-0 font-semibold ${style?.color ?? "text-term-text"}`}>{label}</span>
      <span className="flex min-w-0 items-center gap-2">
        <span className="truncate text-term-text">{displayIdentity(e)}</span>
        {e.plate && (
          <span
            className="shrink-0 rounded border border-term-border px-1 text-[11px] font-semibold tracking-wide text-term-amber"
            title={t("booth.plateTitle")}
          >
            {e.plate}
          </span>
        )}
      </span>
      <span className="text-term-muted">#{e.index}</span>
      {showDetail && (
        <div className="col-start-3 col-end-5 flex flex-wrap items-center gap-x-2 gap-y-1">
          {badges.map((k) => (
            <span
              key={k}
              className="rounded-sm bg-term-red/15 px-1.5 py-px text-[10px] font-semibold uppercase tracking-wide text-term-red"
            >
              {t(k)}
            </span>
          ))}
          {via && (
            <span className="rounded-sm bg-term-cyan/15 px-1.5 py-px text-[10px] font-semibold uppercase tracking-wide text-term-cyan">
              {t(via)}
            </span>
          )}
          {detail && (
            <span className={`text-[11px] ${isAnomaly ? "text-term-red/90" : "text-term-muted"}`}>{detail}</span>
          )}
        </div>
      )}
    </button>
  );
}

/** One label/value line in the event-detail modal. */
function DetailRow({ label, children }: { label: string; children: ReactNode }) {
  return (
    <div className="grid grid-cols-[8rem_1fr] gap-3 border-b border-term-border/40 py-1.5 text-[12px]">
      <span className="text-[11px] uppercase tracking-wider text-term-muted">{label}</span>
      <span className="min-w-0 break-words text-term-text">{children}</span>
    </div>
  );
}

/** Full read-only detail for one ledger event: business fields + the human-readable
 *  reason + the session's entry/exit snapshots, then the signed-chain provenance
 *  (signature/prev-hash/key) for an audit trail. Read-only — the ledger is immutable;
 *  this only DISPLAYS the signed record. */
function EventDetailModal({ e, onClose }: { e: LedgerEvent; onClose: () => void }) {
  const { t } = useTranslation();
  const style = EVENT_STYLE[e.type];
  const label = style ? t(style.labelKey) : e.type.toUpperCase();
  const p = e.payload;
  const reason = renderReason(p, t);
  const amount = paymentSummary(p);
  const badges = eventBadges(p);
  const isAnomaly = e.type === "anomaly";

  // Pretty money for any minor-unit amount in the payload.
  const money =
    p && typeof p.amountMinor === "number" && typeof p.currency === "string"
      ? formatMoney(p.amountMinor, p.currency)
      : null;
  // Pull out the business fields worth a labelled row. Everything else (and the raw
  // bytes) lives behind the audit disclosure — the operator sees a clean summary.
  const sessionRef = typeof p?.sessionRef === "string" ? p.sessionRef : null;
  const plate = typeof p?.plate === "string" ? p.plate : null;
  const category = typeof p?.category === "string" ? p.category : null;
  const operator = typeof p?.operator === "string" ? p.operator : null;
  const tariffVersionId = typeof p?.tariffVersionId === "string" ? p.tariffVersionId : null;

  return (
    <Modal open onClose={onClose} title={t("booth.eventDetail")} width="max-w-2xl">
      <div className="flex flex-col gap-3">
        {/* Headline: the type + localized reason, prominent for anomalies. */}
        <div className={`rounded-term border p-3 ${isAnomaly ? "border-term-red/50 bg-term-red/5" : "border-term-border bg-term-panel-2"}`}>
          <div className={`text-sm font-bold uppercase tracking-widest ${style?.color ?? "text-term-text"}`}>{label}</div>
          {(reason || money) && (
            <div className={`mt-1 text-[13px] ${isAnomaly ? "text-term-red/90" : "text-term-text"}`}>
              {reason ?? money}
            </div>
          )}
          {!reason && !money && isAnomaly && (
            <div className="mt-1 text-[13px] text-term-red/90">{t("booth.evtNoReason")}</div>
          )}
          {badges.length > 0 && (
            <div className="mt-2 flex flex-wrap gap-1.5">
              {badges.map((k) => (
                <span
                  key={k}
                  className="rounded-sm bg-term-red/15 px-1.5 py-px text-[10px] font-semibold uppercase tracking-wide text-term-red"
                >
                  {t(k)}
                </span>
              ))}
            </div>
          )}
        </div>

        {/* Humanized fields — labelled rows, not raw JSON. Only what applies renders. */}
        <div>
          <DetailRow label={t("booth.edTime")}>{new Date(e.occurredAt).toLocaleString()}</DetailRow>
          <DetailRow label={t("booth.edIndex")}>#{e.index}</DetailRow>
          {e.direction && <DetailRow label={t("booth.edDirection")}>{e.direction}</DetailRow>}
          {e.source && <DetailRow label={t("booth.edSource")}>{e.source}</DetailRow>}
          <DetailRow label={t("booth.edIdentity")}>{displayIdentity(e)}</DetailRow>
          {/* When we showed a subscriber NAME above, also expose the raw occurrence id
              (the SUBSESS-… session key) for traceability against the ledger. */}
          {e.subscriberLabel && e.identity && (
            <DetailRow label={t("booth.edOccurrence")}>
              <code className="text-[11px] text-term-muted">{e.identity}</code>
            </DetailRow>
          )}
          {money && (
            <DetailRow label={t("booth.edAmount")}>
              <span className="text-term-cyan">{money}</span>
            </DetailRow>
          )}
          {typeof p?.tender === "string" && <DetailRow label={t("booth.edTender")}>{p.tender}</DetailRow>}
          {viaKey(p) && (
            <DetailRow label={t("booth.edVia")}>
              <span className="text-term-cyan">{t(viaKey(p)!)}</span>
            </DetailRow>
          )}
          {category && <DetailRow label={t("booth.edCategory")}>{category}</DetailRow>}
          {plate && <DetailRow label={t("booth.edPlate")}>{plate}</DetailRow>}
          {operator && <DetailRow label={t("booth.edOperator")}>{operator}</DetailRow>}
          {sessionRef && sessionRef !== e.identity && (
            <DetailRow label={t("booth.edSession")}>{sessionRef}</DetailRow>
          )}
          {tariffVersionId && (
            <DetailRow label={t("booth.edTariffVersion")}>
              <code className="text-[11px] text-term-muted">{tariffVersionId}</code>
            </DetailRow>
          )}
        </div>

        {/* The entry/exit evidence images for this session's identity. */}
        {e.identity && (
          <div>
            <div className="mb-1.5 text-[11px] uppercase tracking-wider text-term-muted">{t("booth.edSnapshots")}</div>
            <SnapshotStrip identity={e.identity} />
          </div>
        )}

        {/* Audit data — collapsed by default. The signed-chain provenance (signature,
            key, prev-hash) and the raw payload are an auditor's concern, not the
            operator's; tucking them behind a disclosure keeps the common view clean
            while preserving the tamper-evidence trail on demand. */}
        <details className="rounded-term border border-term-border bg-term-panel-2">
          <summary className="cursor-pointer select-none px-3 py-2 text-[11px] uppercase tracking-wider text-term-muted hover:text-term-text">
            {t("booth.edAuditData")}
          </summary>
          <div className="border-t border-term-border px-3 pb-3 pt-1">
            <DetailRow label={t("booth.edSignature")}>
              <code className="break-all text-[11px] text-term-muted">{e.signature}</code>
            </DetailRow>
            <DetailRow label={t("booth.edKeyId")}>
              <code className="text-[11px] text-term-muted">{e.keyId}</code>
            </DetailRow>
            <DetailRow label={t("booth.edPrevHash")}>
              <code className="break-all text-[11px] text-term-muted">{e.prevHash ?? "—"}</code>
            </DetailRow>
            <div className="mb-1.5 mt-3 text-[11px] uppercase tracking-wider text-term-muted">
              {t("booth.edRawPayload")}
            </div>
            {p && Object.keys(p).length > 0 ? (
              <pre className="overflow-x-auto rounded-term border border-term-border bg-term-bg p-2 text-[11px] text-term-text">
                {JSON.stringify(p, null, 2)}
              </pre>
            ) : (
              <div className="text-[12px] text-term-muted">{t("booth.edNoPayload")}</div>
            )}
          </div>
        </details>
      </div>
    </Modal>
  );
}

/** Ticket entry: an HID barcode scanner types the id and presses Enter; a manual
 *  operator types it. Either way, submit opens the pay/exit modal for that id. The
 *  input auto-focuses and re-focuses after a scan so the scanner always lands here. */
function TicketInput({ onSubmit }: { onSubmit: (identity: string) => void }) {
  const { t } = useTranslation();
  const [value, setValue] = useState("");
  const ref = useRef<HTMLInputElement>(null);
  return (
    <form
      className="flex items-center gap-2"
      onSubmit={(e) => {
        e.preventDefault();
        const id = value.trim();
        if (id) {
          onSubmit(id);
          setValue("");
          ref.current?.focus();
        }
      }}
    >
      <input
        ref={ref}
        autoFocus
        value={value}
        onChange={(e) => setValue(e.target.value)}
        placeholder={t("booth.scanPlaceholder")}
        inputMode="numeric"
        className="input h-11 flex-1 px-3 text-lg tabular-nums"
      />
      <button type="submit" className="btn btn-primary btn-lg">
        {t("booth.open")}
      </button>
    </form>
  );
}

export function BoothScreen() {
  const { t } = useTranslation();
  // The site-wide shift drives the log scope: the feed shows ONLY the open shift's
  // window (per-shift logs, not all history). When no shift is open, the feed is
  // empty and the operator is prompted to open one.
  const { isOpen: shiftOpen, startedAt: shiftStart } = useShift();

  // Initial load via Query (also the fallback if the WS is briefly down). The events
  // query is scoped to the current shift's start so it never shows prior shifts.
  const occQuery = useQuery({ queryKey: qk.occupancy, queryFn: fetchOccupancy });
  const eventsQuery = useQuery({
    queryKey: [...qk.events, shiftStart ?? "none"],
    queryFn: () => fetchEvents(100, shiftStart ?? undefined),
    enabled: shiftOpen,
  });

  // The ticket currently open in the pay/exit modal (null = no modal).
  const [activeTicket, setActiveTicket] = useState<string | null>(null);
  // The ledger event open in the read-only detail modal (null = closed).
  const [detailEvent, setDetailEvent] = useState<LedgerEvent | null>(null);

  // Live-feed filters: free-text search, event category, and direction/source.
  const [feedSearch, setFeedSearch] = useState("");
  const [feedType, setFeedType] = useState<FeedCat | "">("");
  const [feedDir, setFeedDir] = useState<"entry" | "exit" | "">("");
  const [feedSrc, setFeedSrc] = useState<"booth" | "reader" | "">("");

  // Live overlays from the WS store.
  const liveOcc = useLiveStore((s) => s.occupancy);
  const liveFeed = useLiveStore((s) => s.feed);

  // Prefer the live-pushed occupancy; fall back to the query.
  const occ = liveOcc ?? occQuery.data ?? null;

  // Merge: live events first (newest), then the queried history, de-duped by id —
  // then clip to the current shift window (the live store spans shifts; the feed
  // must not show events from before this shift's start). No shift → no feed.
  const seen = new Set(liveFeed.map((e) => e.id));
  const history = (eventsQuery.data?.events ?? []).filter((e) => !seen.has(e.id));
  const merged = [...liveFeed, ...history].slice(0, 200);
  const scoped =
    shiftOpen && shiftStart
      ? merged.filter((e) => e.occurredAt >= shiftStart)
      : [];

  // Apply the live-feed filters. Source maps to booth (operator-initiated `manual`)
  // vs reader (device-initiated: wiegand/lpr/qr/ticket). Search spans identity,
  // subscriber label, and any advisory plate on the payload.
  const fq = feedSearch.trim().toLowerCase();
  const events = scoped.filter((e) => {
    if (feedType && feedCat(e.type) !== feedType) return false;
    if (feedDir && e.direction !== feedDir) return false;
    if (feedSrc) {
      const isBooth = e.source === "manual";
      if (feedSrc === "booth" ? !isBooth : isBooth) return false;
    }
    if (fq) {
      const hay = `${e.identity ?? ""} ${e.subscriberLabel ?? ""} ${e.payload?.plate ?? ""}`.toLowerCase();
      if (!hay.includes(fq)) return false;
    }
    return true;
  });

  const feedTypeOpts: SegOption<FeedCat>[] = [
    { value: "entry", label: t("booth.fEvtEntry") },
    { value: "exit", label: t("booth.fEvtExit") },
    { value: "pay", label: t("booth.fEvtPay") },
    { value: "void", label: t("booth.fEvtVoid") },
    { value: "anomaly", label: t("booth.fEvtAnomaly") },
  ];
  const feedDirOpts: SegOption<"entry" | "exit">[] = [
    { value: "entry", label: t("booth.fDirEntry") },
    { value: "exit", label: t("booth.fDirExit") },
  ];
  const feedSrcOpts: SegOption<"booth" | "reader">[] = [
    { value: "booth", label: t("booth.fSrcBooth") },
    { value: "reader", label: t("booth.fSrcReader") },
  ];

  return (
    <div className="grid h-full grid-cols-1 gap-3 lg:grid-cols-[minmax(320px,1fr)_2fr] lg:grid-rows-[auto_1fr]">
      {/* Ticket input spans both columns at the top — the operator's primary action. */}
      <div className="lg:col-span-2">
        <Panel title={t("booth.processTicket")}>
          <TicketInput onSubmit={setActiveTicket} />
        </Panel>
      </div>

      {/* Left column: occupancy gauge above the active-sessions list. */}
      <div className="flex min-h-0 flex-col gap-3">
        <Panel title={t("booth.occupancy")} right={<StatusDot />}>
          {occ ? (
            <OccupancyGauge occ={occ} />
          ) : (
            <div className="text-term-muted">{occQuery.isError ? t("booth.occUnavailable") : t("common.loading")}</div>
          )}
        </Panel>
        <div className="flex min-h-0 flex-1 flex-col">
          <ActiveSessions onPick={setActiveTicket} />
        </div>
      </div>

      <Panel
        title={t("booth.liveFeed")}
        right={
          <span className="text-[10px] uppercase tracking-wider text-term-muted">
            {events.length}
            {events.length !== scoped.length ? `/${scoped.length}` : ""} {t("booth.events")}
          </span>
        }
        className="min-h-0"
      >
        <div className="flex h-full flex-col">
          {shiftOpen && (
            <FilterBar search={feedSearch} onSearch={setFeedSearch} searchPlaceholder={t("booth.filterSearchFeed")}>
              <SegGroup
                value={feedType}
                options={feedTypeOpts}
                onChange={setFeedType}
                allLabel={t("booth.filterAll")}
              />
              <SegGroup value={feedDir} options={feedDirOpts} onChange={setFeedDir} allLabel={t("booth.filterAll")} />
              <SegGroup value={feedSrc} options={feedSrcOpts} onChange={setFeedSrc} allLabel={t("booth.filterAll")} />
            </FilterBar>
          )}
          <div className="min-h-0 flex-1 overflow-y-auto pr-1">
            {!shiftOpen ? (
              <div className="text-term-amber">{t("shift.gateTitle")}</div>
            ) : events.length === 0 ? (
              <div className="text-term-muted">
                {eventsQuery.isLoading
                  ? t("common.loading")
                  : scoped.length === 0
                    ? t("booth.noEventsYet")
                    : t("booth.noMatch")}
              </div>
            ) : (
              events.map((e) => <EventRow key={e.id} e={e} onOpen={setDetailEvent} />)
            )}
          </div>
        </div>
      </Panel>

      {activeTicket && <BoothPayModal identity={activeTicket} onClose={() => setActiveTicket(null)} />}
      {detailEvent && <EventDetailModal e={detailEvent} onClose={() => setDetailEvent(null)} />}
    </div>
  );
}