import { useEffect, useState } from 'react';
import {
  AlertTriangle,
  Copy,
  ExternalLink,
  QrCode,
  RefreshCw,
  ScanLine,
  Server,
  Smartphone,
  Trash2,
} from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { QRCodeCanvas } from '@/components/ui/qrcode';
import { QRScannerModal } from '@/components/wallet/QRScannerModal';
import { useCoordinator, useCoordinatorHealth, type CoordinatorHealthStatus } from '@/hooks/useCoordinator';
import { useTranslation } from '@/contexts/language';
import { toast } from '@/hooks/useToast';
import {
  CORDN_APP_URL,
  CORDN_DOCKER_COMMAND,
  CORDN_RELAY_URL,
  coordinatorAddUrl,
  parseCoordinatorInput,
  shortNpub,
  SKATESPOTS_COORDINATOR,
} from '@/lib/coordinator';
import { cn } from '@/lib/utils';

function timeAgo(unixSeconds: number, t: (key: string, params?: Record<string, string | number>) => string): string {
  const s = Math.floor(Date.now() / 1000 - unixSeconds);
  if (s < 60) return t('socialUi.coordinator.secondsAgo', { count: s });
  const m = Math.floor(s / 60);
  if (m < 60) return t('socialUi.coordinator.minutesAgo', { count: m });
  const h = Math.floor(m / 60);
  if (h < 24) return t('socialUi.coordinator.hoursAgo', { count: h });
  return t('socialUi.coordinator.daysAgo', { count: Math.floor(h / 24) });
}

const STATUS_META: Record<
  CoordinatorHealthStatus,
  { label: string; color: string; ring: string; dot: string }
> = {
  idle: { label: 'socialUi.coordinator.statusIdle', color: 'text-gray-400', ring: 'border-white/10', dot: 'bg-gray-500' },
  checking: { label: 'socialUi.coordinator.statusChecking', color: 'text-blue-300', ring: 'border-blue-500/30', dot: 'bg-blue-400' },
  online: { label: 'socialUi.coordinator.statusOnline', color: 'text-green-400', ring: 'border-green-500/30', dot: 'bg-green-400' },
  stale: { label: 'socialUi.coordinator.statusStale', color: 'text-amber-400', ring: 'border-amber-500/30', dot: 'bg-amber-400' },
  offline: { label: 'socialUi.coordinator.statusOffline', color: 'text-red-400', ring: 'border-red-500/30', dot: 'bg-red-500' },
  error: { label: 'socialUi.coordinator.statusError', color: 'text-red-400', ring: 'border-red-500/30', dot: 'bg-red-500' },
};

async function copyText(text: string, copiedText: string, failedTitle: string, failedDesc: string) {
  try {
    await navigator.clipboard.writeText(text);
    toast({ title: copiedText });
  } catch {
    toast({ title: failedTitle, description: failedDesc, variant: 'destructive' });
  }
}

/**
 * Settings → Coordinator.
 *
 * Lets a user point SkateSpots at a Cordn coordinator they've chosen or run
 * themselves — and, crucially, makes "run one on a phone" a hand-off to Cordn
 * rather than something we embed. The connected state is an honest presence
 * probe: a ContextVM server is visible only if it announces.
 */
export function CoordinatorSettingsCard() {
  const { t } = useTranslation();
  const { coordinator, setCoordinator, removeCoordinator } = useCoordinator();
  const { status, lastSeen, eventCount, name, error, check } = useCoordinatorHealth(coordinator);

  const [input, setInput] = useState('');
  const [showQr, setShowQr] = useState(false);
  const [scanOpen, setScanOpen] = useState(false);

  // Probe once when a coordinator is set/changed, so the state is "connected"
  // without the user pressing anything.
  useEffect(() => {
    if (coordinator) void check();
  }, [coordinator, check]);

  const handleAdd = (raw: string) => {
    const parsed = parseCoordinatorInput(raw);
    if (!parsed) {
      toast({
        variant: 'destructive',
        title: t('socialUi.coordinator.notACoordinator'),
        description: t('socialUi.coordinator.notACoordinatorDesc'),
      });
      return;
    }
    setCoordinator({
      pubkey: parsed.pubkey,
      relays: parsed.relays.length ? parsed.relays : [CORDN_RELAY_URL],
    });
    setInput('');
    toast({ title: t('socialUi.coordinator.added'), description: shortNpub(parsed.pubkey) });
  };

  const meta = STATUS_META[status];

  return (
    <div className="space-y-4">
      {/* ── Current coordinator, or the empty state ─────────────────────── */}
      {coordinator ? (
        <div className={cn('rounded-2xl border overflow-hidden bg-white/2', meta.ring)}>
          <div className="px-4 py-3.5 border-b border-white/5 flex items-center justify-between gap-3">
            <div className="min-w-0">
              <p className="text-sm font-bold text-white flex items-center gap-2">
                <Server className="h-4 w-4 text-cyan-400" />
                <span className="truncate">{name ?? shortNpub(coordinator.pubkey)}</span>
              </p>
              <p className="text-xs text-muted-foreground mt-0.5 truncate">
                {coordinator.relays.length === 1
                  ? t('socialUi.coordinator.relayOne', { count: coordinator.relays.length })
                  : t('socialUi.coordinator.relayMany', { count: coordinator.relays.length })}
                {lastSeen ? ` · ${t('socialUi.coordinator.lastSeen', { time: timeAgo(lastSeen, t) })}` : ''}
              </p>
            </div>
            <span
              className={cn(
                'shrink-0 flex items-center gap-1.5 text-xs font-bold px-2.5 py-1 rounded-full border',
                meta.ring,
                meta.color,
              )}
            >
              <span className={cn('h-1.5 w-1.5 rounded-full', meta.dot)} />
              {t(meta.label)}
            </span>
          </div>

          <div className="px-4 py-3.5 space-y-3">
            <p className="text-xs leading-relaxed text-muted-foreground">
              {status === 'online' && t('socialUi.coordinator.onlineDesc')}
              {status === 'stale' && t('socialUi.coordinator.staleDesc')}
              {status === 'offline' && t('socialUi.coordinator.offlineDesc')}
              {status === 'error' && (error ?? t('socialUi.coordinator.errorDesc'))}
              {status === 'idle' && t('socialUi.coordinator.idleDesc')}
              {status === 'checking' && t('socialUi.coordinator.checkingDesc')}
              {eventCount > 0 &&
                (eventCount === 1
                  ? ` · ${t('socialUi.coordinator.eventFoundOne', { count: eventCount })}`
                  : ` · ${t('socialUi.coordinator.eventFoundMany', { count: eventCount })}`)}
            </p>

            <div className="flex flex-wrap items-center gap-2">
              <Button size="sm" variant="outline" onClick={() => void check()} disabled={status === 'checking'}>
                <RefreshCw className={cn('mr-1.5 h-3.5 w-3.5', status === 'checking' && 'animate-spin')} />
                {t('socialUi.coordinator.check')}
              </Button>
              <Button size="sm" variant="outline" onClick={() => void copyText(coordinatorAddUrl(coordinator), t('socialUi.coordinator.addLinkCopied'), t('socialUi.coordinator.copyFailed'), t('socialUi.coordinator.copyManually'))}>
                <Copy className="mr-1.5 h-3.5 w-3.5" />
                {t('socialUi.coordinator.addLink')}
              </Button>
              <Button size="sm" variant="outline" onClick={() => setShowQr((v) => !v)}>
                <QrCode className="mr-1.5 h-3.5 w-3.5" />
                QR
              </Button>
              <Button
                size="sm"
                variant="ghost"
                className="ml-auto text-muted-foreground hover:text-red-400"
                onClick={() => {
                  if (window.confirm(t('socialUi.coordinator.removeConfirm'))) removeCoordinator();
                }}
              >
                <Trash2 className="h-3.5 w-3.5" />
              </Button>
            </div>

            {showQr && (
              <div className="flex flex-col items-center gap-2 rounded-xl bg-black/30 border border-white/5 p-4">
                <QRCodeCanvas value={coordinatorAddUrl(coordinator)} size={180} level="M" />
                <p className="text-[11px] text-muted-foreground text-center">
                  {t('socialUi.coordinator.scanToJoin')}
                </p>
              </div>
            )}

            <p className="text-[11px] text-muted-foreground/70 font-mono truncate">
              {shortNpub(coordinator.pubkey)}
            </p>
          </div>
        </div>
      ) : (
        <div className="rounded-2xl border border-cyan-500/25 bg-cyan-500/[0.06] p-4 space-y-3">
          <p className="text-sm font-bold text-white flex items-center gap-2">
            <Server className="h-4 w-4 text-cyan-400" />
            {t('socialUi.coordinator.noCoordinator')}
          </p>
          <p className="text-xs leading-relaxed text-muted-foreground">
            {t('socialUi.coordinator.noCoordinatorDescA')}{' '}
            <strong className="text-white">{t('socialUi.coordinator.encryptedWord')}</strong>{' '}
            {t('socialUi.coordinator.noCoordinatorDescB')}
          </p>
        </div>
      )}

      {/* ── SkateSpots' provided default ───────────────────────────────── */}
      <div className="rounded-2xl border border-white/8 bg-white/2 p-4 space-y-2.5">
        <p className="flex items-center gap-2 text-sm font-bold text-white">
          <Server className="h-4 w-4 text-cyan-400" />
          {t('socialUi.coordinator.ourDefaultTitle')}
        </p>
        <p className="text-xs leading-relaxed text-muted-foreground">
          {t('socialUi.coordinator.ourDefaultDesc')}
        </p>
        <Button size="sm" variant="outline" onClick={() => setCoordinator(SKATESPOTS_COORDINATOR)}>
          {t('socialUi.coordinator.useOurs')}
        </Button>
      </div>

      {/* ── Add / change ────────────────────────────────────────────────── */}
      <div className="rounded-2xl border border-white/8 bg-white/2 p-4 space-y-3">
        <p className="text-sm font-bold text-white">{coordinator ? t('socialUi.coordinator.change') : t('socialUi.coordinator.addTitle')}</p>
        <div className="flex gap-2">
          <Input
            value={input}
            onChange={(e) => setInput(e.target.value)}
            placeholder={t('socialUi.coordinator.inputPlaceholder')}
            spellCheck={false}
            onKeyDown={(e) => {
              if (e.key === 'Enter' && input.trim()) handleAdd(input);
            }}
          />
          <Button size="sm" onClick={() => handleAdd(input)} disabled={!input.trim()} className="shrink-0">
            {t('socialUi.coordinator.add')}
          </Button>
        </div>
        <Button size="sm" variant="outline" onClick={() => setScanOpen(true)}>
          <ScanLine className="mr-1.5 h-3.5 w-3.5" />
          {t('socialUi.coordinator.scanQR')}
        </Button>
      </div>

      {/* ── Run your own (the hand-off) ─────────────────────────────────── */}
      <div className="rounded-2xl border border-white/8 bg-white/2 overflow-hidden">
        <div className="px-4 py-3.5 border-b border-white/5">
          <p className="text-sm font-bold text-white">{t('socialUi.coordinator.runOwn')}</p>
          <p className="mt-1 text-xs leading-relaxed text-muted-foreground">
            {t('socialUi.coordinator.runOwnDesc')}
          </p>
        </div>

        <div className="px-4 py-3.5 space-y-3 border-b border-white/5">
          <p className="flex items-center gap-2 text-xs font-bold text-white">
            <Smartphone className="h-3.5 w-3.5 text-cyan-400" />
            {t('socialUi.coordinator.onPhone')}
          </p>
          <p className="text-xs text-muted-foreground">
            {t('socialUi.coordinator.onPhoneDesc')}
          </p>
          <div className="flex flex-wrap gap-2">
            <a href={CORDN_APP_URL} target="_blank" rel="noopener noreferrer">
              <Button size="sm" variant="outline">
                {t('socialUi.coordinator.openCordn')}
                <ExternalLink className="ml-1.5 h-3.5 w-3.5" />
              </Button>
            </a>
            <Button size="sm" variant="outline" onClick={() => setScanOpen(true)}>
              <ScanLine className="mr-1.5 h-3.5 w-3.5" />
              {t('socialUi.coordinator.scanItsQR')}
            </Button>
          </div>
        </div>

        <div className="px-4 py-3.5 space-y-3">
          <p className="flex items-center gap-2 text-xs font-bold text-white">
            <Server className="h-3.5 w-3.5 text-cyan-400" />
            {t('socialUi.coordinator.onServer')}
          </p>
          <div className="flex items-center gap-2 rounded-xl bg-black/40 border border-white/5 px-3 py-2">
            <code className="flex-1 min-w-0 truncate text-[11px] font-mono text-gray-300">
              {CORDN_DOCKER_COMMAND}
            </code>
            <button
              type="button"
              onClick={() => void copyText(CORDN_DOCKER_COMMAND, t('socialUi.coordinator.commandCopied'), t('socialUi.coordinator.copyFailed'), t('socialUi.coordinator.copyManually'))}
              className="shrink-0 text-muted-foreground hover:text-white transition-colors"
              aria-label={t('socialUi.coordinator.copyCommand')}
            >
              <Copy className="h-3.5 w-3.5" />
            </button>
          </div>
          <p className="flex items-start gap-2 text-[11px] text-amber-400/90 leading-relaxed">
            <AlertTriangle className="mt-0.5 h-3.5 w-3.5 flex-shrink-0" />
            {t('socialUi.coordinator.androidSleep')}
          </p>
        </div>
      </div>

      <p className="px-1 text-[11px] leading-relaxed text-muted-foreground/70">
        {t('socialUi.coordinator.privacyNote')}
      </p>

      <QRScannerModal
        isOpen={scanOpen}
        onClose={() => setScanOpen(false)}
        onResult={(result) => handleAdd(result.value)}
      />
    </div>
  );
}