'use client';

import { useCallback, useEffect, useMemo, useState } from 'react';
import { useTranslations } from 'next-intl';
import Link from 'next/link';
import { PageHeader } from '@/components/layout/page-header';
import { useAuthStore } from '@/lib/stores/auth-store';
import { listServers, pollServer, type ProxmoxServer } from '@/lib/proxmox-api';
import { HealthBar } from '@/components/proxmox/HealthBar';
import { sortServersByHealth, summarizeHealth } from '@/components/proxmox/proxmox-status';
import { ServerCard } from './components/ServerCard';
import { WELL } from '@/components/proxmox/status-styles';

/** Relative Zeitangaben („vor 3 Min.“) bleiben stimmig, ohne neu zu laden. */
const CLOCK_TICK_MS = 60_000;

function RefreshIcon({ spinning }: { spinning: boolean }) {
  return (
    <svg
      aria-hidden="true"
      xmlns="http://www.w3.org/2000/svg"
      width="16"
      height="16"
      viewBox="0 0 24 24"
      fill="none"
      stroke="currentColor"
      strokeWidth="2"
      strokeLinecap="round"
      strokeLinejoin="round"
      className={spinning ? 'animate-spin motion-reduce:animate-none' : ''}
    >
      <path d="M21 12a9 9 0 1 1-2.64-6.36L21 8" />
      <polyline points="21 3 21 8 16 8" />
    </svg>
  );
}

function SkeletonCard() {
  return (
    <div className="rounded-xl bg-card p-4 pl-5 shadow-sm dark:border dark:border-border">
      <div className="flex items-start gap-3">
        <div className="h-8 w-8 rounded-lg bg-muted" />
        <div className="flex-1 space-y-2">
          <div className="h-3.5 w-1/3 rounded bg-muted" />
          <div className="h-3 w-1/2 rounded bg-muted" />
        </div>
        <div className="h-6 w-20 rounded-full bg-muted" />
      </div>
      <div className="mt-4 h-16 rounded-lg bg-muted" />
      <div className="mt-2 h-12 rounded-lg bg-muted" />
    </div>
  );
}

/**
 * Modulseite (quick-260924-h7x, vorher 260923-dhh Aufgabe 6) — liest
 * ausschliesslich aus dem Zwischenlager, das `GET servers` liefert; kein
 * Live-Zugriff bei Proxmox von hier aus (D-05).
 *
 * Aufbau: Kopf, Gesundheitsbalken, Kartenraster sortiert nach Zustand
 * (down, warn, ok, idle, orphan, darin `position`). „Jetzt aktualisieren“
 * loest je Server eine Abfrage aus und laedt danach neu; der Knopf erscheint
 * nur fuer Admins, weil `POST servers/:id/poll` `@Roles(ADMIN, SUPER_ADMIN)`
 * verlangt (260923-le6).
 */
export default function ProxmoxPage() {
  const t = useTranslations('proxmox');
  const user = useAuthStore((s) => s.user);
  const isAdmin = user?.role === 'ADMIN' || user?.role === 'SUPER_ADMIN';

  const [servers, setServers] = useState<ProxmoxServer[] | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [isRefreshing, setIsRefreshing] = useState(false);
  const [now, setNow] = useState(() => Date.now());

  const reload = useCallback(() => {
    listServers()
      .then((list) => {
        setServers(list);
        setNow(Date.now());
      })
      .catch(() => setError(t('loadError')));
  }, [t]);

  useEffect(() => {
    reload();
  }, [reload]);

  useEffect(() => {
    const id = window.setInterval(() => setNow(Date.now()), CLOCK_TICK_MS);
    return () => window.clearInterval(id);
  }, []);

  const handleRefresh = async () => {
    if (!servers || servers.length === 0) return;
    setIsRefreshing(true);
    try {
      await Promise.all(servers.map((server) => pollServer(server.id).catch(() => undefined)));
      reload();
    } finally {
      setIsRefreshing(false);
    }
  };

  const sorted = useMemo(() => (servers ? sortServersByHealth(servers, now) : []), [servers, now]);
  const counts = useMemo(() => summarizeHealth(servers ?? [], now), [servers, now]);

  return (
    <div className="mx-auto max-w-5xl space-y-6 p-3 sm:p-6">
      <PageHeader
        moduleSlug="proxmox"
        title={t('title')}
        description={t('description')}
        actions={
          isAdmin ? (
            <>
              <Link href="/modules/proxmox/settings" className="btn btn-subtle">
                {t('card.settingsNav')}
              </Link>
              {servers !== null && servers.length > 0 && (
                <button
                  type="button"
                  onClick={handleRefresh}
                  disabled={isRefreshing}
                  className="btn btn-primary"
                >
                  <RefreshIcon spinning={isRefreshing} />
                  {isRefreshing ? t('card.refreshing') : t('card.refresh')}
                </button>
              )}
            </>
          ) : undefined
        }
      />

      {error && (
        <p className="rounded-lg border-l-4 border-status-down bg-status-down/8 px-4 py-3 text-sm text-foreground">
          {error}
        </p>
      )}

      {!error && servers === null && (
        <div
          aria-busy="true"
          className="grid animate-pulse gap-4 motion-reduce:animate-none lg:grid-cols-2"
        >
          <span className="sr-only">{t('loading')}</span>
          <SkeletonCard />
          <SkeletonCard />
        </div>
      )}

      {!error && servers !== null && servers.length === 0 && (
        <div className={`${WELL} flex flex-col items-center gap-3 px-6 py-10 text-center`}>
          <svg
            aria-hidden="true"
            xmlns="http://www.w3.org/2000/svg"
            width="28"
            height="28"
            viewBox="0 0 24 24"
            fill="none"
            stroke="currentColor"
            strokeWidth="1.5"
            strokeLinecap="round"
            strokeLinejoin="round"
            className="text-muted-foreground"
          >
            <rect x="3" y="4" width="18" height="7" rx="1.5" />
            <rect x="3" y="13" width="18" height="7" rx="1.5" />
            <line x1="7" y1="7.5" x2="7.01" y2="7.5" />
            <line x1="7" y1="16.5" x2="7.01" y2="16.5" />
          </svg>
          <p className="max-w-md text-sm text-muted-foreground">{t('emptyState')}</p>
          {isAdmin && (
            <Link
              href="/modules/proxmox/settings"
              className="text-sm font-medium text-foreground hover:underline"
            >
              {t('card.settingsLink')}
            </Link>
          )}
        </div>
      )}

      {!error && servers !== null && servers.length > 0 && (
        <>
          <HealthBar counts={counts} />
          {/* Spaltenfluss statt Zeilenraster: eine kurze Karte (z. B. "nicht
              erreichbar") liesse im Raster eine Luecke bis zur hoeheren
              Nachbarkarte; so rueckt die naechste Karte direkt nach. */}
          <ul className="gap-4 lg:columns-2">
            {sorted.map((server) => (
              <li key={server.id} className="mb-4 min-w-0 break-inside-avoid">
                <ServerCard server={server} isAdmin={isAdmin} now={now} />
              </li>
            ))}
          </ul>
        </>
      )}
    </div>
  );
}