import { useRef, useState } from "react";
import { useTranslation } from "react-i18next";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { can, fetchEvents, fetchOccupancy, fetchSiteConfig, issueEntryTicket, type LedgerEvent, type Occupancy } from "./api.js";
import { rootRoute } from "./router.js";
import { qk } from "./lib/query.js";
import { useLiveStore } from "./lib/live-store.js";
import { useShift } from "./lib/use-shift.js";
import { useScanner } from "./lib/use-scanner.js";
import { Panel } from "./ui/Panel.js";
import { StatusDot } from "./ui/StatusDot.js";
import { BoothPayModal } from "./BoothPayModal.js";
import { ActiveSessions } from "./ActiveSessions.js";
import { FilterBar, SegGroup, type SegOption } from "./ui/FilterBar.js";
import { EventDetailModal, EventRow } from "./ui/event-detail.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. */
// 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 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-[0.6875rem] 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-[0.6875rem] 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-[0.6875rem] font-bold uppercase tracking-widest text-term-red">
          {t("booth.lotFull")}
        </div>
      )}
    </div>
  );
}


/** 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.openTicket")}
      </button>
    </form>
  );
}

/** One barrier light — a 3-state indicator mirroring the physical button lamp (relay 3):
 *  - radar present + camera NOT busy → BLINK green↔red (~1 Hz): "detected, not yet confirmed"
 *  - camera busy → SOLID red: a vehicle is confirmed at the lane vicinity
 *  - otherwise → SOLID green: free
 *  Advisory only; it gates nothing. On the ENTRY light, when the operator holds `session:create`
 *  and BOTH presence conditions meet (radar present AND camera busy = a real car at the entry),
 *  the light becomes a CLICKABLE issue-ticket control (broken physical button). Same presence
 *  rule as the physical button; the server re-checks it. See operator-issued-entry.md. */
function BarrierLight({
  label,
  busy,
  radar,
  onIssue,
  issuing,
  bypassRadar,
  bypassCamera,
}: {
  label: string;
  busy: boolean;
  radar: boolean;
  /** When set (entry light + permission), clicking issues an entry ticket — enabled when
   *  both presence conditions are satisfied, treating a BYPASSED signal as satisfied. */
  onIssue?: () => void;
  issuing?: boolean;
  /** Admin bypass of a faulty device: a bypassed signal counts as present (server re-checks). */
  bypassRadar?: boolean;
  bypassCamera?: boolean;
}) {
  const { t } = useTranslation();
  // Blink only when the radar sees something the camera hasn't confirmed.
  const blinking = radar && !busy;
  const solid = busy ? "border-term-red bg-term-red/10 text-term-red" : "border-term-green bg-term-green/10 text-term-green";
  // A bypassed signal counts as satisfied (its device is faulty). The SERVER re-checks the
  // effective gate authoritatively; this only governs button affordance.
  const radarOk = radar || !!bypassRadar;
  const cameraOk = busy || !!bypassCamera;
  const canIssue = !!onIssue && radarOk && cameraOk && !issuing;
  const clickable = !!onIssue && radarOk && cameraOk;
  return (
    <div
      className={`flex items-center gap-2 rounded-term border px-3 py-2 ${blinking ? "lane-blink" : solid} ${
        clickable ? "cursor-pointer hover:brightness-125" : ""
      }`}
      title={clickable ? t("booth.issueEntryTitle") : label}
      onClick={canIssue ? onIssue : undefined}
      role={clickable ? "button" : undefined}
    >
      {/* Barrier glyph: a post + an arm. `currentColor` follows the (possibly blinking) state. */}
      <svg viewBox="0 0 24 24" className="h-5 w-5" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
        <line x1="5" y1="21" x2="5" y2="9" />
        <line x1="5" y1="10" x2="21" y2="6" />
        <circle cx="5" cy="7" r="1.6" fill="currentColor" stroke="none" />
      </svg>
      <div className="leading-tight">
        <div className="text-[0.625rem] uppercase tracking-wider text-term-muted">{label}</div>
        <div className="text-xs font-bold">
          {issuing ? "…" : clickable ? t("booth.issueEntry") : busy ? "●" : blinking ? "◐" : "○"}
        </div>
      </div>
    </div>
  );
}

/** The two lane barrier lights (entry / exit) fed by the live lane-status (camera busy/free)
 *  and lane-presence (radar). The ENTRY light doubles as an operator issue-ticket control when
 *  the physical button is broken (permission + presence gated). */
function LaneIndicators() {
  const { t } = useTranslation();
  const lanes = useLiveStore((s) => s.lanes);
  const radar = useLiveStore((s) => s.radar);
  const { user } = rootRoute.useRouteContext();
  const { isOpen: shiftOpen, isMine } = useShift();
  const qc = useQueryClient();
  const canIssue = can(user, "session:create") && shiftOpen && isMine;
  // Presence-gate bypass flags (admin, for faulty radar/camera). Refetched on interval so a
  // toggle reaches the booth without a reload; the server still re-checks authoritatively.
  const { data: site } = useQuery({
    queryKey: qk.siteConfig,
    queryFn: fetchSiteConfig,
    staleTime: 30_000,
    refetchInterval: 60_000,
  });
  const [msg, setMsg] = useState<{ text: string; ok: boolean } | null>(null);

  const issue = useMutation({
    mutationFn: issueEntryTicket,
    onSuccess: (r) => {
      setMsg({ ok: true, text: t("booth.issueEntryOk", { ticket: r.ticketId }) });
      void qc.invalidateQueries({ queryKey: qk.events });
      void qc.invalidateQueries({ queryKey: qk.occupancy });
      setTimeout(() => setMsg(null), 4000);
    },
    onError: (e) => {
      setMsg({ ok: false, text: (e as Error).message });
      setTimeout(() => setMsg(null), 4000);
    },
  });

  function onIssue() {
    if (window.confirm(t("booth.issueEntryConfirm"))) issue.mutate();
  }

  return (
    <div className="flex items-center gap-2">
      <BarrierLight
        label={t("booth.laneEntry")}
        busy={lanes?.entry ?? false}
        radar={radar?.entry ?? false}
        onIssue={canIssue ? onIssue : undefined}
        issuing={issue.isPending}
        bypassRadar={site?.bypassPresenceRadar ?? false}
        bypassCamera={site?.bypassPresenceCamera ?? false}
      />
      <BarrierLight label={t("booth.laneExit")} busy={lanes?.exit ?? false} radar={radar?.exit ?? false} />
      {msg && (
        <span className={`text-[0.6875rem] ${msg.ok ? "text-term-green" : "text-term-red"}`}>{msg.text}</span>
      )}
    </div>
  );
}

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);

  // A hardware scan opens the pay/exit modal regardless of focus (the operator needn't
  // click the ticket field first). Paused while a modal is already up — a scan must not
  // abandon an in-progress payment (the operator finishes/closes, then scans the next).
  useScanner({ onScan: setActiveTicket, paused: activeTicket != null || detailEvent != null });

  // Live-feed filters: free-text search, event type, and source. (No direction filter —
  // HYRJE/DALJE there just duplicated the entry/exit options already in the Type filter.)
  const [feedSearch, setFeedSearch] = useState("");
  const [feedType, setFeedType] = useState<FeedCat | "">("");
  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 the enriched advisory plate (`e.plate` — the displayed field;
  // the plate is NOT in the signed payload, so `payload.plate` would never match).
  const fq = feedSearch.trim().toLowerCase();
  const events = scoped.filter((e) => {
    if (feedType && feedCat(e.type) !== feedType) 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.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 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.
          The lane barrier lights sit beside it (live vehicle-detection busy/free). */}
      <div className="lg:col-span-2">
        <Panel title={t("booth.processTicket")}>
          <div className="flex flex-wrap items-center gap-3">
            <div className="min-w-[260px] flex-1">
              <TicketInput onSubmit={setActiveTicket} />
            </div>
            <LaneIndicators />
          </div>
        </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-[0.625rem] 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={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>
  );
}