(() => {
  const localTimeFormatter = new Intl.DateTimeFormat('de-DE', {
    day: '2-digit',
    month: '2-digit',
    year: 'numeric',
    hour: '2-digit',
    minute: '2-digit',
    hour12: false,
  });
  for (const node of document.querySelectorAll('[data-local-time]')) {
    const unixTime = Number(node.dataset.localTime || 0);
    if (!Number.isFinite(unixTime) || unixTime <= 0) continue;
    node.textContent = localTimeFormatter.format(new Date(unixTime * 1000)).replace(',', ' ·');
  }

  const updateBanner = document.querySelector('[data-software-update-banner]');
  if (updateBanner) {
    const version = updateBanner.dataset.softwareUpdateBanner || 'unknown';
    const storageKey = 'domain-control:update-banner-seen-version';
    try {
      if (window.localStorage.getItem(storageKey) !== version) {
        window.localStorage.setItem(storageKey, version);
        window.requestAnimationFrame(() => updateBanner.classList.add('should-animate'));
      }
    } catch {
      // A blocked storage API must not make the banner flicker on every page.
    }
  }

  const toast = document.querySelector('[data-toast]');
  if (toast) {
    const reducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    const region = toast.closest('.toast-region');
    const duration = toast.classList.contains('toast-error') ? 6500 : 4800;
    let remaining = duration;
    let startedAt = 0;
    let dismissTimer;
    let timerRunning = false;

    const dismiss = () => {
      if (!toast.isConnected || toast.classList.contains('is-leaving')) return;
      window.clearTimeout(dismissTimer);
      timerRunning = false;
      toast.classList.add('is-leaving');
      if (reducedMotion) {
        region?.remove();
        return;
      }
      window.setTimeout(() => region?.remove(), 220);
    };

    const resume = () => {
      if (timerRunning || toast.classList.contains('is-leaving')) return;
      toast.classList.remove('is-paused');
      startedAt = performance.now();
      timerRunning = true;
      dismissTimer = window.setTimeout(dismiss, remaining);
    };

    const pause = () => {
      if (!timerRunning || toast.classList.contains('is-leaving')) return;
      remaining = Math.max(0, remaining - (performance.now() - startedAt));
      window.clearTimeout(dismissTimer);
      timerRunning = false;
      toast.classList.add('is-paused');
    };

    toast.querySelector('[data-toast-close]')?.addEventListener('click', dismiss);
    toast.addEventListener('pointerenter', pause);
    toast.addEventListener('pointerleave', () => {
      if (!toast.contains(document.activeElement)) resume();
    });
    toast.addEventListener('focusin', pause);
    toast.addEventListener('focusout', () => {
      window.requestAnimationFrame(() => {
        if (!toast.matches(':hover') && !toast.contains(document.activeElement)) resume();
      });
    });
    resume();
  }

  const currentURL = new URL(window.location.href);
  if (currentURL.searchParams.has('notice')) {
    currentURL.searchParams.delete('notice');
    currentURL.searchParams.delete('notice_kind');
    const cleanLocation = `${currentURL.pathname}${currentURL.search}${currentURL.hash}`;
    window.history.replaceState(window.history.state, '', cleanLocation);
  }

  const settingsForm = document.querySelector('[data-settings-form]');
  if (settingsForm) {
    const updaterToggle = settingsForm.querySelector('[data-updater-toggle]');
    const ipv6Toggle = settingsForm.querySelector('[data-ipv6-toggle]');
    const ipv6Settings = settingsForm.querySelector('[data-ipv6-settings]');

    const syncToggleCard = (input) => {
      if (!input) return;
      const card = input.closest('.setting-switch-card');
      card?.classList.toggle('is-enabled', input.checked);
      const label = input.closest('.setting-switch')?.querySelector('b');
      if (label) label.textContent = input.checked ? 'Aktiv' : 'Inaktiv';
    };

    const syncIPv6Settings = () => {
      if (!ipv6Toggle || !ipv6Settings) return;
      ipv6Settings.classList.toggle('is-disabled', !ipv6Toggle.checked);
      ipv6Settings.setAttribute('aria-disabled', String(!ipv6Toggle.checked));
      const textarea = ipv6Settings.querySelector('textarea');
      if (textarea) textarea.required = ipv6Toggle.checked;
    };

    updaterToggle?.addEventListener('change', () => syncToggleCard(updaterToggle));
    ipv6Toggle?.addEventListener('change', () => {
      syncToggleCard(ipv6Toggle);
      syncIPv6Settings();
    });
    syncToggleCard(updaterToggle);
    syncToggleCard(ipv6Toggle);
    syncIPv6Settings();
  }

  const setupForm = document.querySelector('[data-setup-form]');
  if (setupForm) {
    const password = setupForm.querySelector('[data-setup-password]');
    const confirmation = setupForm.querySelector('[data-setup-confirm]');
    const lengthHint = setupForm.querySelector('[data-password-length]');
    const matchHint = setupForm.querySelector('[data-password-match]');

    const syncPasswordGuidance = () => {
      const length = password ? [...password.value].length : 0;
      const longEnough = length >= 15 && length <= 128;
      const matches = Boolean(confirmation?.value) && confirmation.value === password?.value;
      lengthHint?.classList.toggle('is-valid', longEnough);
      matchHint?.classList.toggle('is-valid', matches);
      lengthHint?.setAttribute('data-state', longEnough ? 'valid' : 'pending');
      matchHint?.setAttribute('data-state', matches ? 'valid' : 'pending');
      password?.classList.toggle('is-valid', longEnough);
      confirmation?.classList.toggle('is-valid', matches);
      setupForm.classList.toggle('is-password-ready', longEnough && matches);
      confirmation?.setCustomValidity(confirmation.value && !matches ? 'Die Passphrasen stimmen nicht überein.' : '');
    };

    password?.addEventListener('input', syncPasswordGuidance);
    confirmation?.addEventListener('input', syncPasswordGuidance);
    syncPasswordGuidance();
  }

  for (const form of document.querySelectorAll('[data-target-form]')) {
    const active = form.querySelector('[data-target-active]');
    const staticFields = form.querySelector('[data-static-ip-fields]');
    const ipv4Toggle = form.querySelector('[name="update_ipv4"]');
    const ipv6Toggle = form.querySelector('[name="update_ipv6"]');
    const staticIPv4 = form.querySelector('[data-static-ipv4]');
    const staticIPv6 = form.querySelector('[data-static-ipv6]');
    const requirement = form.querySelector('[data-target-requirement]');
    const submit = form.querySelector('button[type="submit"]');
    const ipv6Enabled = form.dataset.ipv6Enabled !== 'false';
    const ipv4Selected = () => ipv4Toggle ? ipv4Toggle.checked : form.dataset.updateIpv4 === 'true';
    const ipv6Selected = () => ipv6Enabled && (ipv6Toggle ? ipv6Toggle.checked : form.dataset.updateIpv6 === 'true');

    const syncStaticFields = () => {
      if (!active || !staticFields) return;
      const useIPv4 = ipv4Selected();
      const useIPv6 = ipv6Selected();
      const hasFamily = useIPv4 || useIPv6;
      if (active.checked && !hasFamily) active.checked = false;

      active.disabled = !hasFamily;
      active.closest('.switch')?.classList.toggle('switch-disabled', !hasFamily);

      const useStatic = !active.checked && hasFamily;
      staticFields.hidden = !useStatic;
      staticFields.setAttribute('aria-hidden', String(!useStatic));
      if (staticIPv4) {
        staticIPv4.disabled = !useStatic || !useIPv4;
        staticIPv4.required = useStatic && useIPv4;
      }
      if (staticIPv6) {
        staticIPv6.disabled = !useStatic || !useIPv6;
        staticIPv6.required = useStatic && useIPv6;
      }

      const missingStaticIP = useStatic && (
        (useIPv4 && !staticIPv4?.value.trim()) ||
        (useIPv6 && !staticIPv6?.value.trim())
      );
      if (submit) submit.disabled = missingStaticIP;
      if (requirement) requirement.hidden = !missingStaticIP;
    };

    active?.addEventListener('change', syncStaticFields);
    for (const familyToggle of [ipv4Toggle, ipv6Toggle]) {
      familyToggle?.addEventListener('change', () => {
        if (!familyToggle.checked && active) active.checked = false;
        syncStaticFields();
      });
    }
    staticIPv4?.addEventListener('input', syncStaticFields);
    staticIPv6?.addEventListener('input', syncStaticFields);
    syncStaticFields();
  }

  for (const zone of document.querySelectorAll('[data-access-zone]')) {
    const access = zone.querySelector('[data-zone-access]');
    const manage = zone.querySelector('[data-zone-manage]');
    const create = zone.querySelector('[data-zone-create]');
    access?.addEventListener('change', () => {
      if (!access.checked) {
        if (manage) manage.checked = false;
        if (create) create.checked = false;
      }
    });
    manage?.addEventListener('change', () => {
      if (manage.checked && access) access.checked = true;
      if (!manage.checked && create) create.checked = false;
    });
    create?.addEventListener('change', () => {
      if (create.checked) {
        if (access) access.checked = true;
        if (manage) manage.checked = true;
      }
    });
  }

  for (const target of document.querySelectorAll('[data-access-target]')) {
    const access = target.querySelector('[data-target-access]');
    const manage = target.querySelector('[data-target-manage]');
    access?.addEventListener('change', () => {
      if (!access.checked && manage) manage.checked = false;
    });
    manage?.addEventListener('change', () => {
      if (manage.checked && access) access.checked = true;
    });
  }

  for (const form of document.querySelectorAll('[data-dirty-form]')) {
    const submit = form.querySelector('[data-dirty-submit]');
    if (!submit) continue;
    const state = () => new URLSearchParams(new FormData(form)).toString();
    const initialState = state();
    const syncDirtyState = () => {
      const dirty = state() !== initialState;
      submit.disabled = !dirty;
      submit.setAttribute('aria-disabled', String(!dirty));
    };
    form.addEventListener('input', syncDirtyState);
    form.addEventListener('change', syncDirtyState);
    form.addEventListener('submit', (event) => {
      syncDirtyState();
      if (submit.disabled) event.preventDefault();
    });
    syncDirtyState();
  }

  for (const details of document.querySelectorAll('details[data-scroll-page-end]')) {
    details.addEventListener('toggle', () => {
      if (!details.open) return;
      window.requestAnimationFrame(() => {
        window.scrollTo({
          top: document.documentElement.scrollHeight,
          behavior: window.matchMedia('(prefers-reduced-motion: reduce)').matches ? 'auto' : 'smooth',
        });
      });
    });
  }

  const copyButtons = document.querySelectorAll('[data-copy-target]');
  for (const button of copyButtons) {
    button.addEventListener('click', async () => {
      const target = document.getElementById(button.dataset.copyTarget);
      if (!target) return;
      try {
        await navigator.clipboard.writeText(target.textContent);
        const original = button.textContent;
        button.textContent = 'Kopiert';
        window.setTimeout(() => { button.textContent = original; }, 2000);
      } catch {
        button.textContent = 'Manuell kopieren';
      }
    });
  }

  const softwareUpdateForms = [...document.querySelectorAll('[data-software-update-form]')];
  if (softwareUpdateForms.length > 0) {
    const overlay = document.querySelector('[data-software-update-overlay]');
    const title = overlay?.querySelector('[data-software-update-title]');
    const message = overlay?.querySelector('[data-software-update-message]');
    const progress = overlay?.querySelector('[data-software-update-progress]');
    const progressTrack = overlay?.querySelector('[data-software-update-progress-track]');
    const progressLabel = overlay?.querySelector('[data-software-update-progress-label]');
    const percent = overlay?.querySelector('[data-software-update-percent]');
    const close = overlay?.querySelector('[data-software-update-close]');
    const phaseNodes = [...(overlay?.querySelectorAll('[data-update-phase]') || [])];
    const phaseOrder = ['pulling', 'restarting', 'verifying'];
    const phasePresentation = {
      queued: {title: 'Update wird vorbereitet', label: 'Vorbereitung', start: 4, end: 9, timeConstant: 10000},
      pulling: {title: 'Image wird sicher geladen', label: 'Image-Download', start: 12, end: 42, timeConstant: 22000},
      restarting: {title: 'Container wird gewechselt', label: 'Containerwechsel', start: 44, end: 51, timeConstant: 6000},
      reconnecting: {title: 'Verbindung wird aufgebaut', label: 'Neustart', start: 52, end: 57, timeConstant: 15000},
      verifying: {title: 'Neue Instanz wird geprüft', label: 'Healthcheck', start: 58, end: 98, timeConstant: 35000},
      complete: {title: 'Update erfolgreich', label: 'Abgeschlossen', start: 100, end: 100, timeConstant: 1},
      failed: {title: 'Update nicht abgeschlossen', label: 'Angehalten'},
    };
    let polling = false;
    let targetVersion = '';
    let startedAt = 0;
    let lastKnownPhase = 'pulling';
    let currentPhase = '';
    let phaseStartedAt = 0;
    let displayedProgress = 0;
    let progressTimer;
    const progressTickInterval = window.matchMedia('(prefers-reduced-motion: reduce)').matches ? 1000 : 500;

    const formatElapsed = (milliseconds) => {
      const seconds = Math.max(0, Math.floor(milliseconds / 1000));
      return `${String(Math.floor(seconds / 60)).padStart(2, '0')}:${String(seconds % 60).padStart(2, '0')}`;
    };

    const stopProgressTimer = () => {
      if (progressTimer) window.clearTimeout(progressTimer);
      progressTimer = undefined;
    };

    const renderProgress = (value) => {
      const bounded = Math.max(0, Math.min(100, value));
      displayedProgress = Math.max(displayedProgress, bounded);
      if (progress) progress.style.width = `${displayedProgress.toFixed(2)}%`;
      if (percent) percent.textContent = `${Math.floor(displayedProgress)}%`;
      progressTrack?.setAttribute('aria-valuenow', String(Math.floor(displayedProgress)));
    };

    const phaseTime = (raw) => {
      const now = Date.now();
      const parsed = Date.parse(String(raw || ''));
      if (Number.isFinite(parsed) && parsed >= now - (12 * 60 * 1000) && parsed <= now + 60000) {
        return Math.min(parsed, now);
      }
      return now;
    };

    const tickProgress = () => {
      progressTimer = undefined;
      const presentation = phasePresentation[currentPhase];
      if (!presentation || typeof presentation.end !== 'number' || presentation.end <= presentation.start) return;
      const elapsed = Math.max(0, Date.now() - phaseStartedAt);
      const distance = presentation.end - presentation.start;
      const next = presentation.start + distance * (1 - Math.exp(-elapsed / presentation.timeConstant));
      renderProgress(next);
      if (progressLabel) {
        progressLabel.textContent = currentPhase === 'verifying' || currentPhase === 'reconnecting'
          ? `${presentation.label} · ${formatElapsed(elapsed)}`
          : presentation.label;
      }
      progressTimer = window.setTimeout(tickProgress, progressTickInterval);
    };

    const setUpdatePhase = (phase, text, updatedAt = '') => {
      if (!overlay) return;
      const phaseChanged = currentPhase !== phase;
      if (phaseChanged) {
        currentPhase = phase;
        phaseStartedAt = phaseTime(updatedAt);
        stopProgressTimer();
      } else if (updatedAt) {
        phaseStartedAt = Math.min(phaseStartedAt, phaseTime(updatedAt));
      }
      overlay.dataset.updateState = phase;
      overlay.setAttribute('aria-busy', String(phase !== 'complete' && phase !== 'failed'));
      const presentation = phasePresentation[phase] || phasePresentation.queued;
      if (title) title.textContent = presentation.title;
      if (progressLabel) progressLabel.textContent = presentation.label;
      if (typeof presentation.start === 'number') renderProgress(presentation.start);
      if (phaseChanged && presentation.end > presentation.start) tickProgress();
      if (message && text) message.textContent = text;
      if (phaseOrder.includes(phase)) lastKnownPhase = phase;
      const visualPhase = phase === 'reconnecting' || phase === 'failed' ? lastKnownPhase : phase;
      const currentIndex = phaseOrder.indexOf(visualPhase);
      for (const node of phaseNodes) {
        const nodeIndex = phaseOrder.indexOf(node.dataset.updatePhase);
        node.classList.toggle('is-active', nodeIndex === currentIndex && phase !== 'complete' && phase !== 'failed');
        node.classList.toggle('is-complete', currentIndex > nodeIndex || phase === 'complete');
      }
    };

    const pollSoftwareUpdate = async () => {
      if (!polling) return;
      if (Date.now() - startedAt > 12 * 60 * 1000) {
        polling = false;
        setUpdatePhase('failed', 'Das Update dauert ungewöhnlich lange. Der DNS-Dienst läuft unabhängig davon weiter; prüfe den Status erneut.');
        if (close) close.hidden = false;
        return;
      }
      try {
        const response = await fetch('/api/v1/software-update/status', {headers: {'Accept': 'application/json'}, cache: 'no-store'});
        if (!response.ok) throw new Error('status unavailable');
        const state = await response.json();
        const phase = state.phase || 'queued';
        const messages = {
          queued: 'Update ist eingereiht.',
          pulling: 'Das neue Container-Image wird geladen. Der laufende Dienst bleibt dabei online.',
          restarting: 'Der Dienst wechselt kontrolliert auf die neue Version.',
          verifying: 'Die neue Instanz durchläuft den Healthcheck. Dieser Schritt kann etwas dauern.',
          complete: `Version ${state.target_version || targetVersion} ist bereit.`,
          failed: state.message || 'Update fehlgeschlagen. Die bisherige Version bleibt aktiv.',
        };
        setUpdatePhase(phase, messages[phase] || state.message || 'Update läuft.', state.updated_at);
        if (phase === 'complete') {
          polling = false;
          window.setTimeout(() => window.location.assign('/system'), 1400);
          return;
        }
        if (phase === 'failed') {
          polling = false;
          if (close) close.hidden = false;
          return;
        }
      } catch {
        const recoveryPhase = currentPhase === 'verifying' ? 'verifying' : 'reconnecting';
        const recoveryMessage = recoveryPhase === 'verifying'
          ? 'Der Healthcheck läuft weiter – die Statusverbindung wird automatisch wiederhergestellt.'
          : 'Dienst startet neu – Verbindung wird automatisch wiederhergestellt.';
        setUpdatePhase(recoveryPhase, recoveryMessage);
      }
      window.setTimeout(pollSoftwareUpdate, 1500);
    };

    for (const form of softwareUpdateForms) {
      form.addEventListener('submit', async (event) => {
        event.preventDefault();
        if (polling || !overlay) return;
        const formData = new FormData(form);
        const requestBody = new URLSearchParams();
        for (const [name, value] of formData) {
          if (typeof value === 'string') requestBody.append(name, value);
        }
        targetVersion = String(formData.get('version') || '');
        stopProgressTimer();
        currentPhase = '';
        phaseStartedAt = 0;
        displayedProgress = 0;
        lastKnownPhase = 'pulling';
        if (progress) progress.style.width = '0%';
        if (percent) percent.textContent = '0%';
        progressTrack?.setAttribute('aria-valuenow', '0');
        startedAt = Date.now();
        overlay.hidden = false;
        if (close) close.hidden = true;
        document.body.classList.add('software-update-open');
        setUpdatePhase('queued', `Update auf ${targetVersion} wird vorbereitet.`);
        for (const candidate of softwareUpdateForms) candidate.querySelector('button')?.setAttribute('disabled', '');
        try {
          const response = await fetch(form.action, {method: 'POST', body: requestBody, headers: {'Accept': 'application/json'}, credentials: 'same-origin'});
          const contentType = response.headers.get('content-type') || '';
          let result = {};
          if (contentType.includes('application/json')) {
            result = await response.json().catch(() => ({}));
          } else {
            const responseText = (await response.text()).trim();
            if (responseText && !responseText.startsWith('<')) result.message = responseText.slice(0, 240);
          }
          if (!response.ok || !result.accepted) throw new Error(result.message || 'Update konnte nicht gestartet werden.');
          polling = true;
          window.setTimeout(pollSoftwareUpdate, 400);
        } catch (error) {
          setUpdatePhase('failed', error instanceof Error ? error.message : 'Update konnte nicht gestartet werden.');
          if (close) close.hidden = false;
          for (const candidate of softwareUpdateForms) candidate.querySelector('button')?.removeAttribute('disabled');
        }
      });
    }

    close?.addEventListener('click', () => {
      overlay.hidden = true;
      document.body.classList.remove('software-update-open');
      close.hidden = true;
      stopProgressTimer();
      for (const form of softwareUpdateForms) form.querySelector('button')?.removeAttribute('disabled');
    });
  }

  const containerRestartForm = document.querySelector('[data-container-restart-form]');
  if (containerRestartForm) {
    const overlay = document.querySelector('[data-container-restart-overlay]');
    const title = overlay?.querySelector('[data-container-restart-title]');
    const message = overlay?.querySelector('[data-container-restart-message]');
    const close = overlay?.querySelector('[data-container-restart-close]');
    const submit = containerRestartForm.querySelector('button[type="submit"]');
    let polling = false;
    let startedAt = 0;
    let expectedInstance = containerRestartForm.dataset.instanceId || '';
    let consecutiveReady = 0;
    let sawUnavailable = false;

    const setRestartState = (state, heading, text) => {
      if (!overlay) return;
      overlay.dataset.updateState = state;
      overlay.setAttribute('aria-busy', String(state !== 'complete' && state !== 'failed'));
      if (title) title.textContent = heading;
      if (message) message.textContent = text;
    };

    const pollContainerRestart = async () => {
      if (!polling) return;
      if (Date.now() - startedAt > 90 * 1000) {
        polling = false;
        setRestartState('failed', 'Neustart nicht bestätigt', 'Die neue Container-Instanz wurde nicht rechtzeitig erreichbar. Prüfe den Containerstatus am Docker-Host.');
        if (close) close.hidden = false;
        return;
      }
      try {
        const response = await fetch(`/healthz?restart-check=${Date.now()}`, {cache: 'no-store', credentials: 'same-origin'});
        if (!response.ok) throw new Error('healthcheck unavailable');
        const currentInstance = response.headers.get('X-Domain-Control-Instance') || '';
        const isNewInstance = expectedInstance
          ? (currentInstance !== '' && currentInstance !== expectedInstance) || (currentInstance === '' && sawUnavailable)
          : sawUnavailable;
        if (isNewInstance) {
          consecutiveReady += 1;
          setRestartState('restarting', 'Neue Instanz wird geprüft', 'Der Container ist wieder erreichbar. Die Verbindung wird noch einmal bestätigt.');
          if (consecutiveReady >= 2) {
            polling = false;
            setRestartState('complete', 'Container neu gestartet', 'Die neue Container-Instanz ist bereit. Die Seite wird neu geladen.');
            window.setTimeout(() => window.location.assign('/system'), 900);
            return;
          }
        } else {
          consecutiveReady = 0;
          setRestartState('restarting', 'Container wird neu gestartet', 'Die bisherige Instanz wird geordnet beendet.');
        }
      } catch {
        sawUnavailable = true;
        consecutiveReady = 0;
        setRestartState('restarting', 'Verbindung wird aufgebaut', 'Der Container ist kurz nicht erreichbar und startet automatisch neu.');
      }
      window.setTimeout(pollContainerRestart, 700);
    };

    containerRestartForm.addEventListener('submit', async (event) => {
      event.preventDefault();
      if (polling || !overlay) return;
      if (!window.confirm('Den vollständigen DynDNS-Container jetzt neu starten? Der Dienst ist kurz nicht erreichbar.')) return;

      const formData = new FormData(containerRestartForm);
      const requestBody = new URLSearchParams();
      for (const [name, value] of formData) {
        if (typeof value === 'string') requestBody.append(name, value);
      }
      polling = true;
      startedAt = Date.now();
      consecutiveReady = 0;
      sawUnavailable = false;
      overlay.hidden = false;
      if (close) close.hidden = true;
      if (submit) submit.disabled = true;
      document.body.classList.add('software-update-open');
      setRestartState('restarting', 'Neustart wird vorbereitet', 'Die Anwendung wird geordnet beendet und automatisch wieder gestartet.');

      let responseReceived = false;
      try {
        const response = await fetch(containerRestartForm.action, {method: 'POST', body: requestBody, headers: {'Accept': 'application/json'}, credentials: 'same-origin'});
        responseReceived = true;
        const contentType = response.headers.get('content-type') || '';
        const result = contentType.includes('application/json')
          ? await response.json().catch(() => ({}))
          : {message: (await response.text()).trim().slice(0, 240)};
        if (!response.ok || !result.accepted) throw new Error(result.message || 'Container-Neustart konnte nicht gestartet werden.');
        expectedInstance = result.instance_id || expectedInstance;
      } catch (error) {
        if (responseReceived) {
          polling = false;
          setRestartState('failed', 'Neustart nicht gestartet', error instanceof Error ? error.message : 'Container-Neustart konnte nicht gestartet werden.');
          if (close) close.hidden = false;
          if (submit) submit.disabled = false;
          return;
        }
        sawUnavailable = true;
      }
      window.setTimeout(pollContainerRestart, 350);
    });

    close?.addEventListener('click', () => {
      polling = false;
      overlay.hidden = true;
      close.hidden = true;
      document.body.classList.remove('software-update-open');
      if (submit) submit.disabled = false;
    });
  }

  const countdowns = [...document.querySelectorAll('[data-countdown]')];
  const currentIPv4Fields = [...document.querySelectorAll('[data-current-ipv4-placeholder]')];
  const dashboardIPv4 = document.querySelector('[data-dashboard-ipv4]');
  const dashboardIPv6 = document.querySelector('[data-dashboard-ipv6]');
  const recentRuns = document.querySelector('[data-recent-runs]');
  const runNowButton = document.querySelector('[data-run-now-button]');
  if (countdowns.length === 0 && currentIPv4Fields.length === 0 && !dashboardIPv4 && !dashboardIPv6 && !recentRuns && !runNowButton) return;

  let nextRun = Number(countdowns[0]?.dataset.countdown || 0);
  let running = countdowns[0]?.dataset.running === 'true';
  let enabled = countdowns[0]?.dataset.enabled !== 'false';
  let lastRefresh = 0;
  let refreshing = false;
  let recentRunsSignature = '';

  const formatRemaining = (seconds) => {
    const hours = Math.floor(seconds / 3600);
    const minutes = Math.floor((seconds % 3600) / 60);
    const rest = seconds % 60;
    if (hours > 0) return `${hours}:${String(minutes).padStart(2, '0')}:${String(rest).padStart(2, '0')}`;
    return `${String(minutes).padStart(2, '0')}:${String(rest).padStart(2, '0')}`;
  };

  const runStatusClass = (value) => {
    const status = String(value || '').toLowerCase();
    if (status.includes('ok') || status.includes('unverändert') || status.includes('aktualisiert') || status.includes('angelegt')) return 'status-good';
    if (status.includes('error') || status.includes('fehler') || status.includes('partial')) return 'status-bad';
    return 'status-warn';
  };

  const formatRunTime = (unixTime) => {
    const date = new Date(Number(unixTime || 0) * 1000);
    if (Number.isNaN(date.getTime())) return '–';
    const day = String(date.getDate()).padStart(2, '0');
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const hours = String(date.getHours()).padStart(2, '0');
    const minutes = String(date.getMinutes()).padStart(2, '0');
    return `${day}.${month}.${date.getFullYear()} · ${hours}:${minutes}`;
  };

  const renderRecentRuns = (runs) => {
    if (!recentRuns || !Array.isArray(runs)) return;
    const signature = JSON.stringify(runs.map((run) => [run.id, run.started_at_unix, run.status, run.summary]));
    if (signature === recentRunsSignature) return;
    recentRunsSignature = signature;

    if (runs.length === 0) {
      const empty = document.createElement('div');
      empty.className = 'empty-state';
      empty.textContent = 'Noch keine Änderungen oder Fehler protokolliert.';
      recentRuns.replaceChildren(empty);
      return;
    }

    const list = document.createElement('div');
    list.className = 'data-list';
    for (const run of runs) {
      const status = String(run.status || 'unbekannt');
      const statusClass = runStatusClass(status);
      const summary = String(run.summary || '').trim() || (status === 'running' ? 'Aktualisierung läuft' : 'Update-Lauf');
      const row = document.createElement('div');
      row.className = 'data-row';

      const dot = document.createElement('span');
      dot.className = `state-dot ${statusClass}`;
      const details = document.createElement('span');
      const title = document.createElement('strong');
      title.textContent = summary;
      const time = document.createElement('small');
      time.textContent = formatRunTime(run.started_at_unix);
      details.append(title, time);
      const pill = document.createElement('span');
      pill.className = `status-pill ${statusClass}`;
      pill.textContent = status;
      row.append(dot, details, pill);
      list.append(row);
    }
    recentRuns.replaceChildren(list);
  };

  const renderScheduleState = (state) => {
    const lastIPv4 = typeof state.last_ipv4 === 'string' ? state.last_ipv4.trim() : '';
    const lastIPv6 = typeof state.last_ipv6 === 'string' ? state.last_ipv6.trim() : '';
    if (lastIPv4) {
      for (const field of currentIPv4Fields) field.placeholder = lastIPv4;
    }
    if (dashboardIPv4) dashboardIPv4.textContent = lastIPv4 || 'Nicht ermittelt';
    if (dashboardIPv6) dashboardIPv6.textContent = state.ipv6_enabled === false ? 'Deaktiviert' : (lastIPv6 || 'Nicht ermittelt');
    if (runNowButton) {
      runNowButton.disabled = !enabled || running;
      runNowButton.textContent = running ? 'Update läuft' : 'Update jetzt ausführen';
      if (!enabled) runNowButton.title = 'Updater ist deaktiviert';
      else runNowButton.removeAttribute('title');
    }
    if (recentRuns) recentRuns.setAttribute('aria-busy', String(running));
    renderRecentRuns(state.recent_runs);
  };

  const refreshSchedule = async () => {
    if (document.hidden || refreshing) return;
    const now = Date.now();
    if (now - lastRefresh < 2500) return;
    lastRefresh = now;
    refreshing = true;
    try {
      const endpoint = recentRuns ? '/api/v1/scheduler?runs=1' : '/api/v1/scheduler';
      const response = await fetch(endpoint, {headers: {'Accept': 'application/json'}, cache: 'no-store'});
      if (!response.ok) return;
      const state = await response.json();
      nextRun = Number(state.next_run_unix || 0);
      running = Boolean(state.running);
      enabled = state.enabled !== false;
      renderScheduleState(state);
    } catch {
      // Visible scheduler data keeps its last known state when the request fails.
    } finally {
      refreshing = false;
    }
  };

  const tick = () => {
    if (document.hidden) return;
    if (countdowns.length === 0) return;
    if (!enabled) {
      for (const node of countdowns) {
        node.textContent = 'Inaktiv';
        node.setAttribute('aria-label', 'Automatischer Updater ist deaktiviert');
      }
      return;
    }
    const now = Math.floor(Date.now() / 1000);
    const remaining = Math.max(0, nextRun - now);
    const label = running ? 'Update läuft' : (nextRun > 0 ? formatRemaining(remaining) : '--:--');
    for (const node of countdowns) {
      node.textContent = label;
      node.setAttribute('aria-label', running ? 'Update läuft' : `Nächste Aktualisierung in ${remaining} Sekunden`);
    }
    if (running || nextRun === 0 || remaining === 0) refreshSchedule();
  };

  if (countdowns.length > 0) {
    tick();
    window.setInterval(tick, 1000);
  }
  refreshSchedule();
  window.setInterval(refreshSchedule, 30000);
  document.addEventListener('visibilitychange', () => {
    if (document.hidden) return;
    lastRefresh = 0;
    tick();
    refreshSchedule();
  });
})();