import React from 'react';
import { useTranslation } from 'react-i18next';
import { Download, Loader2, Plus, Printer, RotateCcw, Save, UploadCloud } from 'lucide-react';

import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Textarea } from '@/components/ui/textarea';

import type { EventQrInvite, EventQrInviteLayout } from '../../api';
import { authorizedFetch } from '../../auth/tokens';

export type QrLayoutCustomization = {
  layout_id?: string;
  headline?: string;
  subtitle?: string;
  description?: string;
  badge_label?: string;
  instructions_heading?: string;
  instructions?: string[];
  link_heading?: string;
  link_label?: string;
  cta_label?: string;
  accent_color?: string;
  text_color?: string;
  background_color?: string;
  secondary_color?: string;
  badge_color?: string;
  background_gradient?: { angle?: number; stops?: string[] } | null;
  logo_data_url?: string | null;
  logo_url?: string | null;
};

type InviteLayoutCustomizerPanelProps = {
  invite: EventQrInvite | null;
  eventName: string;
  saving: boolean;
  resetting: boolean;
  onSave: (customization: QrLayoutCustomization) => Promise<void>;
  onReset: () => Promise<void>;
  initialCustomization: QrLayoutCustomization | null;
};

const MAX_INSTRUCTIONS = 5;

export function InviteLayoutCustomizerPanel({
  invite,
  eventName,
  saving,
  resetting,
  onSave,
  onReset,
  initialCustomization,
}: InviteLayoutCustomizerPanelProps): JSX.Element {
  const { t } = useTranslation('management');

  const inviteUrl = invite?.url ?? '';
  const defaultInstructions = React.useMemo(() => {
    const value = t('tasks.customizer.defaults.instructions', { returnObjects: true }) as unknown;
    return Array.isArray(value) ? (value as string[]) : ['QR-Code scannen', 'Profil anlegen', 'Fotos teilen'];
  }, [t]);

  const [availableLayouts, setAvailableLayouts] = React.useState<EventQrInviteLayout[]>(invite?.layouts ?? []);
  const [layoutsLoading, setLayoutsLoading] = React.useState(false);
  const [layoutsError, setLayoutsError] = React.useState<string | null>(null);
  const [selectedLayoutId, setSelectedLayoutId] = React.useState<string | undefined>(initialCustomization?.layout_id ?? invite?.layouts?.[0]?.id);
  const [form, setForm] = React.useState<QrLayoutCustomization>({});
  const [instructions, setInstructions] = React.useState<string[]>([]);
  const [error, setError] = React.useState<string | null>(null);
  const formRef = React.useRef<HTMLFormElement | null>(null);

  React.useEffect(() => {
    if (!invite) {
      setAvailableLayouts([]);
      setSelectedLayoutId(undefined);
      return;
    }

    const layouts = invite.layouts ?? [];
    setAvailableLayouts(layouts);
    setLayoutsError(null);
    setSelectedLayoutId((current) => {
      if (current && layouts.some((layout) => layout.id === current)) {
        return current;
      }
      if (initialCustomization?.layout_id && layouts.some((layout) => layout.id === initialCustomization.layout_id)) {
        return initialCustomization.layout_id;
      }
      return layouts[0]?.id;
    });
  }, [invite?.id, initialCustomization?.layout_id]);

  React.useEffect(() => {
    let cancelled = false;

    async function loadLayouts(url: string) {
      try {
        setLayoutsLoading(true);
        setLayoutsError(null);
        const target = (() => {
          try {
            if (url.startsWith('http://') || url.startsWith('https://')) {
              const parsed = new URL(url);
              return parsed.pathname + parsed.search;
            }
          } catch (parseError) {
            console.warn('[Invites] Failed to parse layout URL', parseError);
          }
          return url;
        })();
        console.debug('[Invites] Fetching layouts', target);
        const response = await authorizedFetch(target, {
          method: 'GET',
          headers: { Accept: 'application/json' },
        });

        if (!response.ok) {
          console.error('[Invites] Layout request failed', response.status, response.statusText);
          throw new Error(`Failed with status ${response.status}`);
        }

        const json = await response.json();
        const items = Array.isArray(json?.data) ? (json.data as EventQrInviteLayout[]) : [];
        console.debug('[Invites] Layout response items', items);

        if (!cancelled) {
          setAvailableLayouts(items);
          setSelectedLayoutId((current) => {
            if (current && items.some((layout) => layout.id === current)) {
              return current;
            }
            if (initialCustomization?.layout_id && items.some((layout) => layout.id === initialCustomization.layout_id)) {
              return initialCustomization.layout_id;
            }
            return items[0]?.id;
          });
        }
      } catch (err) {
        if (!cancelled) {
          console.error('[Invites] Failed to load layouts', err);
          setLayoutsError(t('invites.customizer.loadingError', 'Layouts konnten nicht geladen werden.'));
        }
      } finally {
        if (!cancelled) {
          setLayoutsLoading(false);
        }
      }
    }

    if (!invite || availableLayouts.length > 0 || !invite.layouts_url) {
      return () => {
        cancelled = true;
      };
    }

    void loadLayouts(invite.layouts_url);

    return () => {
      cancelled = true;
    };
  }, [invite, availableLayouts.length, initialCustomization?.layout_id, t]);

  React.useEffect(() => {
    if (!availableLayouts.length) {
      return;
    }

    setSelectedLayoutId((current) => {
      if (current && availableLayouts.some((layout) => layout.id === current)) {
        return current;
      }
      if (initialCustomization?.layout_id && availableLayouts.some((layout) => layout.id === initialCustomization.layout_id)) {
        return initialCustomization.layout_id;
      }
      return availableLayouts[0].id;
    });
  }, [availableLayouts, initialCustomization?.layout_id]);

  const activeLayout = React.useMemo(() => {
    if (!availableLayouts.length) {
      return null;
    }

    if (selectedLayoutId) {
      const match = availableLayouts.find((layout) => layout.id === selectedLayoutId);
      if (match) {
        return match;
      }
    }

    return availableLayouts[0];
  }, [availableLayouts, selectedLayoutId]);

  React.useEffect(() => {
    if (!invite || !activeLayout) {
      setForm({});
      setInstructions([]);
      return;
    }

    const baseInstructions = Array.isArray(initialCustomization?.instructions) && initialCustomization.instructions?.length
      ? [...(initialCustomization.instructions as string[])]
      : [...defaultInstructions];

    setInstructions(baseInstructions);

    setForm({
      layout_id: activeLayout.id,
      headline: initialCustomization?.headline ?? eventName,
      subtitle: initialCustomization?.subtitle ?? activeLayout.subtitle ?? '',
      description: initialCustomization?.description ?? activeLayout.description ?? '',
      badge_label: initialCustomization?.badge_label ?? t('tasks.customizer.defaults.badgeLabel'),
      instructions_heading: initialCustomization?.instructions_heading ?? t('tasks.customizer.defaults.instructionsHeading'),
      link_heading: initialCustomization?.link_heading ?? t('tasks.customizer.defaults.linkHeading'),
      link_label: initialCustomization?.link_label ?? inviteUrl,
      cta_label: initialCustomization?.cta_label ?? t('tasks.customizer.defaults.ctaLabel'),
      accent_color: initialCustomization?.accent_color ?? activeLayout.preview?.accent ?? '#6366F1',
      text_color: initialCustomization?.text_color ?? activeLayout.preview?.text ?? '#111827',
      background_color: initialCustomization?.background_color ?? activeLayout.preview?.background ?? '#FFFFFF',
      secondary_color: initialCustomization?.secondary_color ?? 'rgba(15,23,42,0.08)',
      badge_color: initialCustomization?.badge_color ?? activeLayout.preview?.accent ?? '#2563EB',
      background_gradient: initialCustomization?.background_gradient ?? activeLayout.preview?.background_gradient ?? null,
      logo_data_url: initialCustomization?.logo_data_url ?? initialCustomization?.logo_url ?? null,
    });
    setError(null);
  }, [invite?.id, activeLayout?.id, defaultInstructions, initialCustomization, eventName, inviteUrl, t]);

  const effectiveInstructions = instructions.filter((entry) => entry.trim().length > 0);

  function updateForm<T extends keyof QrLayoutCustomization>(key: T, value: QrLayoutCustomization[T]) {
    setForm((prev) => ({ ...prev, [key]: value }));
  }

  function handleLayoutSelect(layout: EventQrInviteLayout) {
    setSelectedLayoutId(layout.id);
    updateForm('layout_id', layout.id);
    setForm((prev) => ({
      ...prev,
      accent_color: prev.accent_color ?? layout.preview?.accent ?? '#6366F1',
      text_color: prev.text_color ?? layout.preview?.text ?? '#111827',
      background_color: prev.background_color ?? layout.preview?.background ?? '#FFFFFF',
      background_gradient: prev.background_gradient ?? layout.preview?.background_gradient ?? null,
    }));
  }

  function handleInstructionChange(index: number, value: string) {
    setInstructions((prev) => {
      const next = [...prev];
      next[index] = value;
      return next;
    });
  }

  function handleAddInstruction() {
    setInstructions((prev) => (prev.length < MAX_INSTRUCTIONS ? [...prev, ''] : prev));
  }

  function handleRemoveInstruction(index: number) {
    setInstructions((prev) => prev.filter((_, idx) => idx !== index));
  }

  function handleLogoUpload(event: React.ChangeEvent<HTMLInputElement>) {
    const file = event.target.files?.[0];
    if (!file) {
      return;
    }

    if (file.size > 1024 * 1024) {
      setError(t('tasks.customizer.errors.logoTooLarge', 'Das Logo darf maximal 1 MB groß sein.'));
      return;
    }

    const reader = new FileReader();
    reader.onload = () => {
      updateForm('logo_data_url', typeof reader.result === 'string' ? reader.result : null);
      setError(null);
    };
    reader.readAsDataURL(file);
  }

  function handleLogoRemove() {
    updateForm('logo_data_url', null);
  }

  async function handleSubmit(event: React.FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!invite || !activeLayout) {
      return;
    }

    const payload: QrLayoutCustomization = {
      ...form,
      layout_id: activeLayout.id,
      instructions: effectiveInstructions,
    };

    await onSave(payload);
  }

  async function handleResetClick() {
    await onReset();
  }

  function handleDownload(format: string, url: string) {
    const link = document.createElement('a');
    link.href = url;
    link.download = `${invite?.token ?? 'invite'}-${format.toLowerCase()}`;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
  }

  function handlePrint(preferredUrl?: string | null) {
    const url = preferredUrl ?? activeLayout?.download_urls?.pdf ?? activeLayout?.download_urls?.a4 ?? null;
    if (!url) {
      setError(t('invites.labels.noPrintSource', 'Keine druckbare Version verfügbar.'));
      return;
    }
    const printWindow = window.open(url, '_blank', 'noopener,noreferrer');
    printWindow?.focus();
  }

  const previewStyles = React.useMemo(() => {
    const gradient = form.background_gradient ?? activeLayout?.preview?.background_gradient ?? null;
    if (gradient?.stops && gradient.stops.length > 0) {
      const angle = gradient.angle ?? 180;
      const stops = gradient.stops.join(', ');
      return { backgroundImage: `linear-gradient(${angle}deg, ${stops})` };
    }
    return { backgroundColor: form.background_color ?? activeLayout?.preview?.background ?? '#F8FAFC' };
  }, [form.background_color, form.background_gradient, activeLayout]);

  if (!invite) {
    return (
      <CardPlaceholder
        title={t('invites.customizer.placeholderTitle', 'Kein Layout verfügbar')}
        description={t('invites.customizer.placeholderCopy', 'Erstelle eine Einladung, damit du Texte, Farben und Drucklayouts bearbeiten kannst.')}
      />
    );
  }

  if (!availableLayouts.length) {
    if (layoutsLoading) {
      return (
        <CardPlaceholder
          title={t('invites.customizer.loadingTitle', 'Layouts werden geladen')}
          description={t('invites.customizer.loadingDescription', 'Bitte warte einen Moment, wir bereiten die Drucklayouts vor.')}
        />
      );
    }

    return (
      <CardPlaceholder
        title={layoutsError ?? t('invites.customizer.placeholderTitle', 'Kein Layout verfügbar')}
        description={layoutsError ?? t('invites.customizer.placeholderCopy', 'Erstelle eine Einladung, damit du Texte, Farben und Drucklayouts bearbeiten kannst.')}
      />
    );
  }

  if (!activeLayout) {
    return (
      <CardPlaceholder
        title={t('invites.customizer.placeholderTitle', 'Kein Layout verfügbar')}
        description={t('invites.customizer.placeholderCopy', 'Erstelle eine Einladung, damit du Texte, Farben und Drucklayouts bearbeiten kannst.')}
      />
    );
  }

  return (
    <div className="space-y-4">
      <div className="flex flex-col gap-4 lg:flex-row lg:items-center lg:justify-between">
        <div>
          <h2 className="text-xl font-semibold text-slate-900">{t('invites.customizer.heading', 'Layout anpassen')}</h2>
          <p className="text-sm text-slate-600">{t('invites.customizer.copy', 'Verleihe der Einladung euren Ton: Texte, Farben und Logo lassen sich live bearbeiten.')}</p>
        </div>
        <div className="flex flex-wrap gap-2">
          <Button variant="outline" onClick={handleResetClick} disabled={resetting || saving}>
            {resetting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <RotateCcw className="mr-2 h-4 w-4" />}
            {t('invites.customizer.actions.reset', 'Zurücksetzen')}
          </Button>
          <Button
            type="button"
            onClick={() => {
              if (formRef.current) {
                if (typeof formRef.current.requestSubmit === 'function') {
                  formRef.current.requestSubmit();
                } else {
                  formRef.current.submit();
                }
              }
            }}
            className="bg-gradient-to-r from-amber-500 via-orange-500 to-rose-500 text-white shadow-lg shadow-rose-500/20"
            disabled={saving || resetting}
          >
            {saving ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Save className="mr-2 h-4 w-4" />}
            {t('invites.customizer.actions.save', 'Layout speichern')}
          </Button>
        </div>
      </div>

      {error ? (
        <div className="rounded-lg border border-rose-200 bg-rose-50 px-4 py-3 text-sm text-rose-700">{error}</div>
      ) : null}

      <div className="grid gap-6 lg:grid-cols-[minmax(0,1.05fr)_minmax(0,1fr)]">
        <form ref={formRef} onSubmit={handleSubmit} className="space-y-6">
          <section className="space-y-4 rounded-2xl border border-slate-100 bg-white/90 p-5 shadow-sm">
            <header>
              <h3 className="text-sm font-semibold uppercase tracking-wide text-slate-500">{t('invites.customizer.sections.layouts', 'Layouts')}</h3>
              <p className="text-xs text-slate-500">{t('invites.customizer.sections.layoutsHint', 'Wähle eine Vorlage als Basis aus. Du kannst jederzeit wechseln.')}</p>
            </header>
            <div className="flex snap-x gap-3 overflow-x-auto pb-2">
              {availableLayouts.map((layout) => (
                <button
                  key={layout.id}
                  type="button"
                  onClick={() => handleLayoutSelect(layout)}
                  className={`min-w-[200px] shrink-0 rounded-xl border p-3 text-left transition-all ${layout.id === selectedLayoutId ? 'border-amber-400 bg-amber-50 shadow' : 'border-slate-200 bg-white hover:border-amber-200'}`}
                >
                  <div className="text-sm font-semibold text-slate-900">{layout.name || t('invites.customizer.layoutFallback', 'Layout')}</div>
                  {layout.description ? <div className="mt-1 text-xs text-slate-500">{layout.description}</div> : null}
                  <div className="mt-3 flex flex-wrap gap-2 text-xs text-slate-500">
                    {layout.formats?.map((format) => (
                      <span key={`${layout.id}-${format}`} className="rounded-full border border-amber-200 px-2 py-0.5 text-amber-600">{String(format).toUpperCase()}</span>
                    ))}
                  </div>
                </button>
              ))}
            </div>
          </section>

          <section className="space-y-4 rounded-2xl border border-slate-100 bg-white/90 p-5 shadow-sm">
            <header>
              <h3 className="text-sm font-semibold uppercase tracking-wide text-slate-500">{t('invites.customizer.sections.text', 'Texte')}</h3>
            </header>
            <div className="grid gap-4">
              <div className="space-y-2">
                <Label htmlFor="invite-headline">{t('invites.customizer.fields.headline', 'Überschrift')}</Label>
                <Input
                  id="invite-headline"
                  value={form.headline ?? ''}
                  onChange={(event) => updateForm('headline', event.target.value)}
                />
              </div>
              <div className="space-y-2">
                <Label htmlFor="invite-subtitle">{t('invites.customizer.fields.subtitle', 'Unterzeile')}</Label>
                <Input
                  id="invite-subtitle"
                  value={form.subtitle ?? ''}
                  onChange={(event) => updateForm('subtitle', event.target.value)}
                />
              </div>
              <div className="space-y-2">
                <Label htmlFor="invite-description">{t('invites.customizer.fields.description', 'Beschreibung')}</Label>
                <Textarea
                  id="invite-description"
                  value={form.description ?? ''}
                  onChange={(event) => updateForm('description', event.target.value)}
                  className="min-h-[96px]"
                />
              </div>
              <div className="grid gap-4 sm:grid-cols-2">
                <div className="space-y-2">
                  <Label htmlFor="invite-badge">{t('invites.customizer.fields.badge', 'Badge-Label')}</Label>
                  <Input
                    id="invite-badge"
                    value={form.badge_label ?? ''}
                    onChange={(event) => updateForm('badge_label', event.target.value)}
                  />
                </div>
                <div className="space-y-2">
                  <Label htmlFor="invite-cta">{t('invites.customizer.fields.cta', 'Call-to-Action')}</Label>
                  <Input
                    id="invite-cta"
                    value={form.cta_label ?? ''}
                    onChange={(event) => updateForm('cta_label', event.target.value)}
                  />
                </div>
              </div>
              <div className="grid gap-4 sm:grid-cols-2">
                <div className="space-y-2">
                  <Label htmlFor="invite-link-heading">{t('invites.customizer.fields.linkHeading', 'Link-Überschrift')}</Label>
                  <Input
                    id="invite-link-heading"
                    value={form.link_heading ?? ''}
                    onChange={(event) => updateForm('link_heading', event.target.value)}
                  />
                </div>
                <div className="space-y-2">
                  <Label htmlFor="invite-link-label">{t('invites.customizer.fields.linkLabel', 'Link/Begleittext')}</Label>
                  <Input
                    id="invite-link-label"
                    value={form.link_label ?? ''}
                    onChange={(event) => updateForm('link_label', event.target.value)}
                  />
                </div>
              </div>
            </div>
          </section>

          <section className="space-y-4 rounded-2xl border border-slate-100 bg-white/90 p-5 shadow-sm">
            <header>
              <div className="flex items-center justify-between">
                <div>
                  <h3 className="text-sm font-semibold uppercase tracking-wide text-slate-500">{t('invites.customizer.sections.instructions', 'Schritt-für-Schritt')}</h3>
                  <p className="text-xs text-slate-500">{t('invites.customizer.sections.instructionsHint', 'Helft euren Gästen mit klaren Aufgaben. Maximal fünf Punkte.')}</p>
                </div>
                <Button type="button" variant="outline" size="sm" onClick={handleAddInstruction} disabled={instructions.length >= MAX_INSTRUCTIONS}>
                  <Plus className="mr-1 h-4 w-4" />
                  {t('invites.customizer.actions.addInstruction', 'Punkt hinzufügen')}
                </Button>
              </div>
            </header>
            <div className="space-y-2">
              <Label htmlFor="invite-instruction-heading">{t('invites.customizer.fields.instructionsHeading', 'Abschnittsüberschrift')}</Label>
              <Input
                id="invite-instruction-heading"
                value={form.instructions_heading ?? ''}
                onChange={(event) => updateForm('instructions_heading', event.target.value)}
              />
            </div>
            <div className="space-y-3">
              {instructions.map((entry, index) => (
                <div key={`instruction-${index}`} className="flex gap-2">
                  <Input
                    value={entry}
                    onChange={(event) => handleInstructionChange(index, event.target.value)}
                    placeholder={t('invites.customizer.fields.instructionPlaceholder', 'Beschreibung des Schritts')}
                  />
                  <Button
                    type="button"
                    variant="ghost"
                    className="text-slate-500 hover:text-rose-500"
                    onClick={() => handleRemoveInstruction(index)}
                  >
                    ×
                  </Button>
                </div>
              ))}
            </div>
          </section>

          <section className="space-y-4 rounded-2xl border border-slate-100 bg-white/90 p-5 shadow-sm">
            <header>
              <h3 className="text-sm font-semibold uppercase tracking-wide text-slate-500">{t('invites.customizer.sections.branding', 'Branding')}</h3>
            </header>
            <div className="grid gap-4 sm:grid-cols-2">
              <div className="space-y-2">
                <Label htmlFor="invite-accent">{t('invites.customizer.fields.accentColor', 'Akzentfarbe')}</Label>
                <Input
                  id="invite-accent"
                  type="color"
                  value={form.accent_color ?? '#6366F1'}
                  onChange={(event) => updateForm('accent_color', event.target.value)}
                  className="h-11"
                />
              </div>
              <div className="space-y-2">
                <Label htmlFor="invite-text-color">{t('invites.customizer.fields.textColor', 'Textfarbe')}</Label>
                <Input
                  id="invite-text-color"
                  type="color"
                  value={form.text_color ?? '#111827'}
                  onChange={(event) => updateForm('text_color', event.target.value)}
                  className="h-11"
                />
              </div>
              <div className="space-y-2">
                <Label htmlFor="invite-background-color">{t('invites.customizer.fields.backgroundColor', 'Hintergrund')}</Label>
                <Input
                  id="invite-background-color"
                  type="color"
                  value={form.background_color ?? '#FFFFFF'}
                  onChange={(event) => updateForm('background_color', event.target.value)}
                  className="h-11"
                />
              </div>
              <div className="space-y-2">
                <Label htmlFor="invite-badge-color">{t('invites.customizer.fields.badgeColor', 'Badge')}</Label>
                <Input
                  id="invite-badge-color"
                  type="color"
                  value={form.badge_color ?? '#2563EB'}
                  onChange={(event) => updateForm('badge_color', event.target.value)}
                  className="h-11"
                />
              </div>
            </div>

            <div className="space-y-2">
              <Label>{t('invites.customizer.fields.logo', 'Logo')}</Label>
              {form.logo_data_url ? (
                <div className="flex items-center gap-4 rounded-lg border border-slate-200 bg-slate-50 p-3">
                  <img src={form.logo_data_url} alt="Logo" className="h-12 w-12 rounded border border-slate-200 object-contain" />
                  <Button type="button" variant="ghost" onClick={handleLogoRemove} className="text-rose-500 hover:text-rose-600">
                    {t('invites.customizer.actions.removeLogo', 'Logo entfernen')}
                  </Button>
                </div>
              ) : (
                <label className="flex cursor-pointer items-center gap-3 rounded-lg border border-dashed border-slate-300 bg-slate-50/80 px-4 py-3 text-sm text-slate-500 hover:border-amber-200">
                  <UploadCloud className="h-4 w-4" />
                  <span>{t('invites.customizer.actions.uploadLogo', 'Logo hochladen (max. 1 MB)')}</span>
                  <input type="file" accept="image/*" className="hidden" onChange={handleLogoUpload} />
                </label>
              )}
            </div>
          </section>

          <div className="flex justify-end gap-2">
            <Button type="button" variant="outline" onClick={handleResetClick} disabled={resetting || saving}>
              {resetting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <RotateCcw className="mr-2 h-4 w-4" />}
              {t('invites.customizer.actions.reset', 'Zurücksetzen')}
            </Button>
            <Button type="submit" disabled={saving || resetting} className="bg-gradient-to-r from-amber-500 via-orange-500 to-rose-500 text-white">
              {saving ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <Save className="mr-2 h-4 w-4" />}
              {t('invites.customizer.actions.save', 'Layout speichern')}
            </Button>
          </div>
        </form>

        <aside className="space-y-4 rounded-2xl border border-slate-100 bg-white/90 p-5 shadow-sm">
          <div className="flex items-center justify-between">
            <div>
              <h3 className="text-sm font-semibold uppercase tracking-wide text-slate-500">{t('invites.customizer.preview.title', 'Live-Vorschau')}</h3>
              <p className="text-xs text-slate-500">{t('invites.customizer.preview.subtitle', 'So sieht dein Layout beim Export aus.')}</p>
            </div>
            <div className="flex gap-2">
              <Button type="button" variant="outline" size="sm" onClick={() => handlePrint(activeLayout.download_urls?.pdf ?? activeLayout.download_urls?.a4)}>
                <Printer className="mr-1 h-4 w-4" />
                {t('invites.customizer.actions.print', 'Drucken')}
              </Button>
              {activeLayout.formats?.map((format) => {
                const key = String(format ?? '').toLowerCase();
                const url = activeLayout.download_urls?.[key];
                if (!url) return null;
                return (
                  <Button key={`${activeLayout.id}-${key}`} type="button" variant="outline" size="sm" onClick={() => handleDownload(key, url)}>
                    <Download className="mr-1 h-4 w-4" />
                    {key.toUpperCase()}
                  </Button>
                );
              })}
            </div>
          </div>

          <div className="space-y-4 rounded-xl border border-slate-200 bg-white p-5 shadow-inner">
            <div className="rounded-xl p-5 text-slate-900" style={previewStyles}>
              <div className="flex items-start justify-between">
                <span
                  className="rounded-full px-3 py-1 text-xs font-semibold uppercase tracking-wide"
                  style={{ backgroundColor: form.badge_color ?? form.accent_color ?? '#2563EB', color: '#ffffff' }}
                >
                  {form.badge_label || t('tasks.customizer.defaults.badgeLabel')}
                </span>
                <div className="flex h-14 w-14 items-center justify-center rounded-full bg-white/80 shadow" style={{ color: form.accent_color ?? '#2563EB' }}>
                  <SmileIcon />
                </div>
              </div>
              <div className="mt-6 space-y-2">
                <h4 className="text-lg font-semibold leading-tight" style={{ color: form.text_color ?? '#111827' }}>
                  {form.headline || eventName}
                </h4>
                {form.subtitle ? (
                  <p className="text-sm" style={{ color: form.text_color ?? '#111827', opacity: 0.75 }}>
                    {form.subtitle}
                  </p>
                ) : null}
              </div>
              {form.description ? (
                <p className="mt-4 text-sm" style={{ color: form.text_color ?? '#111827' }}>
                  {form.description}
                </p>
              ) : null}
              <div className="mt-5 grid gap-3 rounded-xl bg-white/80 p-4">
                <div className="text-xs font-semibold uppercase tracking-wide text-slate-500">{form.instructions_heading}</div>
                <ol className="grid gap-2 text-sm text-slate-700">
                  {effectiveInstructions.slice(0, 4).map((item, index) => (
                    <li key={`preview-instruction-${index}`} className="flex gap-2">
                      <span className="font-semibold" style={{ color: form.accent_color ?? '#2563EB' }}>{index + 1}.</span>
                      <span>{item}</span>
                    </li>
                  ))}
                </ol>
              </div>
              <div className="mt-5 flex flex-col gap-2 rounded-xl bg-white/80 p-4 text-sm text-slate-700">
                <span className="text-xs font-semibold uppercase tracking-wide text-slate-500">{form.link_heading}</span>
                <div className="flex items-center justify-between gap-2">
                  <span className="truncate font-medium" style={{ color: form.accent_color ?? '#2563EB' }}>
                    {form.link_label || inviteUrl}
                  </span>
                <span className="rounded-full bg-slate-900/90 px-3 py-1 text-xs text-white">QR</span>
                </div>
                <Button size="sm" className="w-full bg-gradient-to-r from-amber-500 via-orange-500 to-rose-500 text-white">
                  {form.cta_label || t('tasks.customizer.defaults.ctaLabel')}
                </Button>
              </div>
            </div>
            {form.logo_data_url ? (
              <div className="flex items-center justify-center rounded-lg border border-dashed border-slate-200 bg-slate-50 py-4">
                <img src={form.logo_data_url} alt="Logo preview" className="max-h-16 object-contain" />
              </div>
            ) : null}
          </div>
        </aside>
      </div>
    </div>
  );
}

function CardPlaceholder({ title, description }: { title: string; description: string }) {
  return (
    <div className="rounded-2xl border border-dashed border-slate-200 bg-slate-50/80 p-10 text-center text-sm text-slate-500">
      <h3 className="text-base font-semibold text-slate-700">{title}</h3>
      <p className="mt-2 text-sm text-slate-500">{description}</p>
    </div>
  );
}

function SmileIcon(): JSX.Element {
  return (
    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" className="h-5 w-5">
      <circle cx="12" cy="12" r="10" opacity="0.4" />
      <path d="M8 14s1.5 2 4 2 4-2 4-2" />
      <path d="M9 9h.01M15 9h.01" strokeLinecap="round" strokeLinejoin="round" />
    </svg>
  );
}