import { useState } from "react";
import { createFileRoute } from "@tanstack/react-router";
import { useQueryClient } from "@tanstack/react-query";
import {
  KeyRound,
  CheckCircle2,
  Smartphone,
  Timer,
  Trash2,
  UserPlus,
  X,
} from "lucide-react";
import {
  useGetNativePairing,
  useArmNativePairing,
  useDisarmNativePairing,
  useListNativeClients,
  useUnpairNativeClient,
  useListPendingDevices,
  useApprovePendingDevice,
  useDenyPendingDevice,
  getGetNativePairingQueryKey,
  getListNativeClientsQueryKey,
  getListPendingDevicesQueryKey,
} from "@/api/gen/native/native";
import {
  useGetPairingStatus,
  useSubmitPairingPin,
  getGetPairingStatusQueryKey,
} from "@/api/gen/pairing/pairing";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { QueryState } from "@/components/query-state";
import { m } from "@/paraglide/messages";
import { useLocale } from "@/lib/i18n";

export const Route = createFileRoute("/pairing")({ component: PairingPage });

/** Seconds → `m:ss`. */
function fmtTime(secs: number): string {
  const s = Math.max(0, Math.floor(secs));
  return `${Math.floor(s / 60)}:${(s % 60).toString().padStart(2, "0")}`;
}

function PairingPage() {
  useLocale();
  return (
    <div className="space-y-6">
      <h1 className="text-2xl font-semibold">{m.pairing_title()}</h1>
      <PendingDevices />
      <NativePairingCard />
      <NativeDevices />
      <MoonlightPairingCard />
    </div>
  );
}

/** Seconds since a knock → a short relative label. */
function fmtAge(secs: number): string {
  if (secs < 10) return m.pairing_pending_age_just_now();
  if (secs < 60) return m.pairing_pending_age_secs({ s: Math.floor(secs) });
  return m.pairing_pending_age_mins({ min: Math.floor(secs / 60) });
}

/**
 * Devices awaiting delegated approval: an unpaired device that tried to connect shows up here,
 * and Approve pairs it on the spot — no PIN fetched out of band. Renders nothing while empty
 * (the common case); polls so a knock appears while the operator is looking at the page.
 */
function PendingDevices() {
  const qc = useQueryClient();
  const pending = useListPendingDevices({ query: { refetchInterval: 3_000 } });
  const approve = useApprovePendingDevice();
  const deny = useDenyPendingDevice();
  const rows = pending.data ?? [];
  // Stay out of the way when there's nothing pending and the fetch is healthy — but DON'T swallow
  // a real error (a 500 etc.); fall through to QueryState below so it surfaces like every other
  // section. (A 401 is handled globally by the fetcher's redirect-to-login.)
  if (rows.length === 0 && !pending.error) return null;

  const refresh = () => {
    qc.invalidateQueries({ queryKey: getListPendingDevicesQueryKey() });
    qc.invalidateQueries({ queryKey: getListNativeClientsQueryKey() });
  };
  const onApprove = (id: number, currentName: string) => {
    const name = prompt(m.pairing_pending_name_prompt(), currentName);
    if (name == null) return; // operator cancelled
    approve.mutate(
      { id, data: { name: name.trim() ? name.trim() : null } },
      { onSuccess: refresh },
    );
  };

  return (
    <div className="space-y-2">
      <h2 className="flex items-center gap-2 text-lg font-medium">
        <UserPlus className="size-4" />
        {m.pairing_pending_title()}
      </h2>
      <p className="text-sm text-muted-foreground">
        {m.pairing_pending_desc()}
      </p>
      <QueryState
        isLoading={pending.isLoading}
        error={pending.error}
        refetch={pending.refetch}
      >
        <Card>
          <CardContent className="p-0">
            <Table>
              <TableBody>
                {rows.map((p) => (
                  <TableRow key={p.id}>
                    <TableCell className="font-medium">{p.name}</TableCell>
                    <TableCell className="font-mono text-xs text-muted-foreground">
                      {p.fingerprint.slice(0, 16)}…
                    </TableCell>
                    <TableCell className="text-xs text-muted-foreground">
                      {fmtAge(p.age_secs)}
                    </TableCell>
                    <TableCell className="text-right">
                      <div className="flex justify-end gap-2">
                        <Button
                          size="sm"
                          disabled={approve.isPending || deny.isPending}
                          onClick={() => onApprove(p.id, p.name)}
                        >
                          {m.pairing_pending_approve()}
                        </Button>
                        <Button
                          size="sm"
                          variant="ghost"
                          aria-label={m.pairing_pending_deny()}
                          disabled={approve.isPending || deny.isPending}
                          onClick={() =>
                            deny.mutate({ id: p.id }, { onSuccess: refresh })
                          }
                        >
                          <X className="size-4" />
                        </Button>
                      </div>
                    </TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          </CardContent>
        </Card>
      </QueryState>
    </div>
  );
}

/** Native (punktfunk/1) pairing: arm a window → DISPLAY the PIN the user enters on their device. */
function NativePairingCard() {
  const qc = useQueryClient();
  // Poll fast while armed (live countdown), slow otherwise.
  const status = useGetNativePairing({
    query: { refetchInterval: (q) => (q.state.data?.armed ? 1_000 : 4_000) },
  });
  const arm = useArmNativePairing();
  const disarm = useDisarmNativePairing();
  const d = status.data;
  const refresh = () =>
    qc.invalidateQueries({ queryKey: getGetNativePairingQueryKey() });

  return (
    <QueryState
      isLoading={status.isLoading}
      error={status.error}
      refetch={status.refetch}
    >
      <Card className="max-w-md">
        <CardHeader>
          <CardTitle className="flex items-center gap-2">
            <Smartphone className="size-4" />
            {m.pairing_native_title()}
          </CardTitle>
        </CardHeader>
        <CardContent className="space-y-4">
          {!d?.enabled ? (
            <p className="text-sm text-muted-foreground">
              {m.pairing_native_disabled()}
            </p>
          ) : d.armed && d.pin ? (
            <div className="space-y-3">
              <p className="text-sm">{m.pairing_native_enter()}</p>
              <div className="rounded-lg border bg-muted/40 py-5 text-center font-mono text-4xl font-semibold tracking-[0.3em]">
                {d.pin}
              </div>
              {d.expires_in_secs != null && (
                <p className="flex items-center justify-center gap-1.5 text-sm text-muted-foreground">
                  <Timer className="size-4" />
                  {m.pairing_native_expires()} {fmtTime(d.expires_in_secs)}
                </p>
              )}
              <Button
                variant="outline"
                className="w-full"
                disabled={disarm.isPending}
                onClick={() => disarm.mutate(undefined, { onSuccess: refresh })}
              >
                {m.pairing_native_cancel()}
              </Button>
            </div>
          ) : (
            <>
              <p className="text-sm text-muted-foreground">
                {m.pairing_native_desc()}
              </p>
              <Button
                disabled={arm.isPending}
                onClick={() =>
                  arm.mutate(
                    { data: { ttl_secs: 120 } },
                    { onSuccess: refresh },
                  )
                }
              >
                <KeyRound className="size-4" />
                {m.pairing_native_arm()}
              </Button>
            </>
          )}
        </CardContent>
      </Card>
    </QueryState>
  );
}

/** The paired native (punktfunk/1) devices, with unpair. */
function NativeDevices() {
  const qc = useQueryClient();
  const clients = useListNativeClients();
  const unpair = useUnpairNativeClient();
  const rows = clients.data ?? [];

  const onUnpair = (fingerprint: string) => {
    if (!confirm(m.pairing_native_unpair_confirm())) return;
    unpair.mutate(
      { fingerprint },
      {
        onSuccess: () =>
          qc.invalidateQueries({ queryKey: getListNativeClientsQueryKey() }),
      },
    );
  };

  return (
    <div className="space-y-2">
      <h2 className="text-lg font-medium">{m.pairing_native_devices()}</h2>
      <QueryState
        isLoading={clients.isLoading}
        error={clients.error}
        refetch={clients.refetch}
      >
        {rows.length === 0 ? (
          <Card>
            <CardContent className="p-6 text-center text-sm text-muted-foreground">
              {m.pairing_native_empty()}
            </CardContent>
          </Card>
        ) : (
          <Card>
            <CardContent className="p-0">
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>{m.clients_name()}</TableHead>
                    <TableHead>{m.clients_fingerprint()}</TableHead>
                    <TableHead className="w-12" />
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {rows.map((c) => (
                    <TableRow key={c.fingerprint}>
                      <TableCell className="font-medium">
                        {c.name || "—"}
                      </TableCell>
                      <TableCell className="font-mono text-xs text-muted-foreground">
                        {c.fingerprint.slice(0, 16)}…
                      </TableCell>
                      <TableCell>
                        <Button
                          variant="ghost"
                          size="icon"
                          aria-label={m.action_unpair()}
                          disabled={unpair.isPending}
                          onClick={() => onUnpair(c.fingerprint)}
                        >
                          <Trash2 className="size-4 text-destructive" />
                        </Button>
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            </CardContent>
          </Card>
        )}
      </QueryState>
    </div>
  );
}

/** GameStream/Moonlight pairing: the client shows a PIN, the operator submits it here. */
function MoonlightPairingCard() {
  const qc = useQueryClient();
  const [pin, setPin] = useState("");
  const pairing = useGetPairingStatus({ query: { refetchInterval: 2_000 } });
  const submit = useSubmitPairingPin();
  const pending = pairing.data?.pin_pending ?? false;

  const onSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    submit.mutate(
      { data: { pin } },
      {
        onSuccess: () => {
          setPin("");
          qc.invalidateQueries({ queryKey: getGetPairingStatusQueryKey() });
        },
      },
    );
  };

  return (
    <QueryState
      isLoading={pairing.isLoading}
      error={pairing.error}
      refetch={pairing.refetch}
    >
      <Card className="max-w-md">
        <CardHeader>
          <CardTitle className="flex items-center gap-2">
            <KeyRound className="size-4" />
            {m.pairing_moonlight_title()}
          </CardTitle>
        </CardHeader>
        <CardContent>
          {!pending ? (
            <p className="text-sm text-muted-foreground">{m.pairing_idle()}</p>
          ) : (
            <form onSubmit={onSubmit} className="space-y-4">
              <p className="text-sm">{m.pairing_waiting()}</p>
              <div className="space-y-2">
                <Label htmlFor="pin">{m.pairing_pin_label()}</Label>
                <Input
                  id="pin"
                  inputMode="numeric"
                  autoComplete="off"
                  maxLength={8}
                  value={pin}
                  onChange={(e) => setPin(e.target.value.replace(/\D/g, ""))}
                  placeholder="0000"
                  className="font-mono text-lg tracking-widest"
                />
              </div>
              <Button
                type="submit"
                disabled={pin.length < 4 || submit.isPending}
              >
                {m.pairing_submit()}
              </Button>
              {submit.isSuccess && (
                <p className="flex items-center gap-1.5 text-sm text-[var(--success)]">
                  <CheckCircle2 className="size-4" />
                  {m.pairing_success()}
                </p>
              )}
              {submit.isError && (
                <p className="text-sm text-destructive">{m.pairing_failed()}</p>
              )}
            </form>
          )}
        </CardContent>
      </Card>
    </QueryState>
  );
}