import { useParams, Link } from 'react-router';
import { useQuery } from '@tanstack/react-query';
import {
  ArrowLeft,
  Network,
  Wifi,
  WifiOff,
  Cpu,
  MemoryStick,
  HardDrive,
  Server,
  Activity,
} from 'lucide-react';
import { api } from '@/lib/api';
import { formatBytes } from '@/lib/utils';
import { Button } from '@/components/ui/button';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Progress } from '@/components/ui/progress';

interface NodeDetail {
  id: string;
  name: string;
  fqdn: string;
  daemonPort: number;
  grpcPort: number;
  memoryTotal: number;
  diskTotal: number;
  isOnline: boolean;
  daemonVersion: string | null;
  createdAt: string;
}

interface NodeStats {
  cpuPercent: number;
  memoryUsed: number;
  memoryTotal: number;
  diskUsed: number;
  diskTotal: number;
  activeServers: number;
  totalServers: number;
  uptime: number;
}

interface ServerSummary {
  id: string;
  name: string;
  status: string;
  memoryLimit: number;
  cpuLimit: number;
  gameName: string;
}

export function NodeDetailPage() {
  const { orgId, nodeId } = useParams();

  const { data: node } = useQuery({
    queryKey: ['node', orgId, nodeId],
    queryFn: () => api.get<NodeDetail>(`/organizations/${orgId}/nodes/${nodeId}`),
  });

  const { data: stats } = useQuery({
    queryKey: ['node-stats', orgId, nodeId],
    queryFn: () => api.get<NodeStats>(`/organizations/${orgId}/nodes/${nodeId}/stats`),
    refetchInterval: 10_000,
  });

  const { data: serversData } = useQuery({
    queryKey: ['node-servers', orgId, nodeId],
    queryFn: () =>
      api.get<{ data: ServerSummary[] }>(
        `/organizations/${orgId}/nodes/${nodeId}/servers`,
      ),
  });

  const servers = serversData?.data ?? [];

  if (!node) {
    return (
      <div className="flex items-center justify-center py-12">
        <div className="h-8 w-8 animate-spin rounded-full border-2 border-primary border-t-transparent" />
      </div>
    );
  }

  const memPercent = stats
    ? Math.round((stats.memoryUsed / stats.memoryTotal) * 100)
    : 0;
  const diskPercent = stats
    ? Math.round((stats.diskUsed / stats.diskTotal) * 100)
    : 0;

  return (
    <div className="space-y-6">
      <div className="flex items-center gap-3">
        <Link to={`/org/${orgId}/nodes`}>
          <Button variant="ghost" size="sm">
            <ArrowLeft className="h-4 w-4" />
          </Button>
        </Link>
        <div className="flex items-center gap-3">
          <Network className="h-6 w-6 text-primary" />
          <div>
            <h1 className="text-2xl font-bold">{node.name}</h1>
            <p className="text-sm text-muted-foreground">
              {node.fqdn}:{node.daemonPort}
            </p>
          </div>
          <Badge variant={node.isOnline ? 'default' : 'destructive'}>
            {node.isOnline ? (
              <><Wifi className="mr-1 h-3 w-3" /> Online</>
            ) : (
              <><WifiOff className="mr-1 h-3 w-3" /> Offline</>
            )}
          </Badge>
        </div>
      </div>

      {/* Stats Cards */}
      <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-4">
        <Card>
          <CardHeader className="flex flex-row items-center justify-between pb-2">
            <CardTitle className="text-sm font-medium">CPU Usage</CardTitle>
            <Cpu className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats ? `${stats.cpuPercent.toFixed(1)}%` : '—'}
            </div>
            <Progress value={stats?.cpuPercent ?? 0} className="mt-2 h-2" />
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between pb-2">
            <CardTitle className="text-sm font-medium">Memory</CardTitle>
            <MemoryStick className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats
                ? `${formatBytes(stats.memoryUsed)} / ${formatBytes(stats.memoryTotal)}`
                : '—'}
            </div>
            <Progress value={memPercent} className="mt-2 h-2" />
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between pb-2">
            <CardTitle className="text-sm font-medium">Disk</CardTitle>
            <HardDrive className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats
                ? `${formatBytes(stats.diskUsed)} / ${formatBytes(stats.diskTotal)}`
                : '—'}
            </div>
            <Progress value={diskPercent} className="mt-2 h-2" />
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between pb-2">
            <CardTitle className="text-sm font-medium">Servers</CardTitle>
            <Server className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats ? `${stats.activeServers} / ${stats.totalServers}` : servers.length.toString()}
            </div>
            <p className="mt-1 text-xs text-muted-foreground">
              {stats ? 'active / total' : 'total servers'}
            </p>
          </CardContent>
        </Card>
      </div>

      {/* Node Info */}
      <div className="grid gap-4 sm:grid-cols-2">
        <Card>
          <CardHeader>
            <CardTitle>Node Information</CardTitle>
          </CardHeader>
          <CardContent className="space-y-3">
            <InfoRow label="FQDN" value={node.fqdn} />
            <InfoRow label="Daemon Port" value={String(node.daemonPort)} />
            <InfoRow label="gRPC Port" value={String(node.grpcPort)} />
            <InfoRow label="Total Memory" value={formatBytes(node.memoryTotal)} />
            <InfoRow label="Total Disk" value={formatBytes(node.diskTotal)} />
            {node.daemonVersion && (
              <InfoRow label="Daemon Version" value={node.daemonVersion} />
            )}
            <InfoRow label="Created" value={new Date(node.createdAt).toLocaleDateString()} />
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <CardTitle>Servers on this Node</CardTitle>
          </CardHeader>
          <CardContent>
            {servers.length === 0 ? (
              <p className="py-4 text-center text-sm text-muted-foreground">
                No servers on this node
              </p>
            ) : (
              <div className="space-y-2">
                {servers.map((srv) => (
                  <Link
                    key={srv.id}
                    to={`/org/${orgId}/servers/${srv.id}/console`}
                    className="flex items-center justify-between rounded-lg border p-3 transition-colors hover:bg-muted/50"
                  >
                    <div>
                      <p className="font-medium">{srv.name}</p>
                      <p className="text-xs text-muted-foreground">{srv.gameName}</p>
                    </div>
                    <div className="flex items-center gap-2">
                      <Badge
                        variant={srv.status === 'running' ? 'default' : 'outline'}
                      >
                        {srv.status}
                      </Badge>
                      <span className="text-xs text-muted-foreground">
                        {formatBytes(srv.memoryLimit)} RAM
                      </span>
                    </div>
                  </Link>
                ))}
              </div>
            )}
          </CardContent>
        </Card>
      </div>
    </div>
  );
}

function InfoRow({ label, value }: { label: string; value: string }) {
  return (
    <div className="flex items-center justify-between text-sm">
      <span className="text-muted-foreground">{label}</span>
      <span className="font-medium">{value}</span>
    </div>
  );
}