/**
 * CVMHealthCheck — owner-only status probe for the SkateSpots ContextVM server.
 *
 * Renders NOTHING unless the logged-in user is one of the two platform owners
 * (PLATFORM_OWNER_PUBKEYS). Pings the ContextVM relay for the server's own
 * events and reports online / stale / offline with a last-seen timestamp.
 */

import { useCurrentUser } from '@/hooks/useCurrentUser';
import { PLATFORM_OWNER_PUBKEYS } from '@/hooks/useListingRestrictions';
import {
  useCVMServerHealth,
  CVM_SERVER_PUBKEY,
  CVM_RELAY,
  type CVMHealthStatus,
} from '@/hooks/useCVMServerHealth';
import { cn } from '@/lib/utils';
import {
  Activity,
  CheckCircle2,
  XCircle,
  AlertTriangle,
  Loader2,
  ExternalLink,
} from 'lucide-react';

function timeAgo(unixSeconds: number): string {
  const s = Math.floor(Date.now() / 1000 - unixSeconds);
  if (s < 60) return `${s}s ago`;
  const m = Math.floor(s / 60);
  if (m < 60) return `${m}m ago`;
  const h = Math.floor(m / 60);
  if (h < 24) return `${h}h ago`;
  const d = Math.floor(h / 24);
  return `${d}d ago`;
}

const STATUS_META: Record<
  CVMHealthStatus,
  { label: string; color: string; ring: string; dot: string }
> = {
  idle: { label: 'Not checked', color: 'text-gray-400', ring: 'border-white/10', dot: 'bg-gray-500' },
  checking: { label: 'Checking…', color: 'text-blue-300', ring: 'border-blue-500/30', dot: 'bg-blue-400' },
  online: { label: 'Online', color: 'text-green-400', ring: 'border-green-500/30', dot: 'bg-green-400' },
  stale: { label: 'Stale', color: 'text-amber-400', ring: 'border-amber-500/30', dot: 'bg-amber-400' },
  offline: { label: 'Offline', color: 'text-red-400', ring: 'border-red-500/30', dot: 'bg-red-500' },
  error: { label: 'Unreachable', color: 'text-red-400', ring: 'border-red-500/30', dot: 'bg-red-500' },
};

export function CVMHealthCheck() {
  const { user } = useCurrentUser();
  const health = useCVMServerHealth();

  // Owner-only gate. Never render for anyone else.
  const isOwner = !!user?.pubkey && PLATFORM_OWNER_PUBKEYS.includes(user.pubkey);
  if (!isOwner) return null;

  const meta = STATUS_META[health.status];

  const StatusIcon =
    health.status === 'checking'
      ? Loader2
      : health.status === 'online'
      ? CheckCircle2
      : health.status === 'stale'
      ? AlertTriangle
      : health.status === 'idle'
      ? Activity
      : XCircle;

  return (
    <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">
            <Activity className="h-4 w-4 text-red-400" />
            ContextVM Server
            <span className="text-[9px] font-black uppercase tracking-widest text-red-400/70 bg-red-500/10 px-1.5 py-0.5 rounded">
              Owner
            </span>
          </p>
          <p className="text-xs text-muted-foreground mt-0.5">
            Health probe for the Sasquatch CVM data server
          </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)} />
          {meta.label}
        </span>
      </div>

      <div className="px-4 py-3.5 space-y-3">
        {/* Status detail line */}
        <div className="flex items-start gap-2.5">
          <StatusIcon
            className={cn(
              'h-4 w-4 mt-0.5 shrink-0',
              meta.color,
              health.status === 'checking' && 'animate-spin',
            )}
          />
          <div className="text-xs leading-relaxed">
            {health.status === 'idle' && (
              <span className="text-muted-foreground">
                Tap “Check server” to ping the ContextVM relay for the server’s heartbeat.
              </span>
            )}
            {health.status === 'checking' && (
              <span className="text-blue-300">Querying {CVM_RELAY}…</span>
            )}
            {health.status === 'online' && health.lastSeen && (
              <span className="text-green-400">
                Server is announcing. Last event {timeAgo(health.lastSeen)}.
              </span>
            )}
            {health.status === 'stale' && health.lastSeen && (
              <span className="text-amber-400">
                Server found, but last activity was {timeAgo(health.lastSeen)} — it may be
                down or idle.
              </span>
            )}
            {health.status === 'offline' && (
              <span className="text-red-400">
                No events from the server on the relay. It’s likely not running.
              </span>
            )}
            {health.status === 'error' && (
              <span className="text-red-400">{health.error}</span>
            )}
          </div>
        </div>

        {/* Meta grid */}
        {(health.eventCount > 0 || health.checkedAt) && (
          <div className="grid grid-cols-2 gap-2 text-[11px]">
            <div className="rounded-lg bg-black/30 border border-white/5 px-2.5 py-2">
              <p className="text-gray-500 uppercase tracking-wide font-bold text-[9px]">
                Events found
              </p>
              <p className="text-white font-mono">{health.eventCount}</p>
            </div>
            <div className="rounded-lg bg-black/30 border border-white/5 px-2.5 py-2">
              <p className="text-gray-500 uppercase tracking-wide font-bold text-[9px]">
                Last seen
              </p>
              <p className="text-white font-mono">
                {health.lastSeen ? timeAgo(health.lastSeen) : '—'}
              </p>
            </div>
          </div>
        )}

        {/* Note — Sasquatch does NOT depend on this server. */}
        <p className="text-[11px] text-muted-foreground/70 leading-relaxed">
          Note: Sasquatch queries data relays directly — it keeps working even if this
          server is down. This check is for operations only.
        </p>

        {/* Actions */}
        <div className="flex items-center gap-2 pt-0.5">
          <button
            onClick={health.check}
            disabled={health.status === 'checking'}
            className="flex items-center gap-2 text-sm font-bold text-red-400 hover:text-red-300 disabled:opacity-50 transition-colors"
          >
            {health.status === 'checking' ? (
              <Loader2 className="h-4 w-4 animate-spin" />
            ) : (
              <Activity className="h-4 w-4" />
            )}
            Check server
          </button>
          <a
            href={`https://contextvm.org/s/${CVM_SERVER_PUBKEY}`}
            target="_blank"
            rel="noopener noreferrer"
            className="ml-auto flex items-center gap-1.5 text-xs font-semibold text-gray-400 hover:text-white transition-colors"
          >
            Directory <ExternalLink className="h-3.5 w-3.5" />
          </a>
        </div>
      </div>
    </div>
  );
}