/**
 * Admin: Kalenderverwaltung (plan.md Abschnitt 13: /admin/calendars/[id]).
 * Bearbeiten, deaktivieren und Mitglieder verwalten.
 */
import { redirect } from 'next/navigation';
import { prisma } from '@/lib/db/client';
import { requireCalendarContext } from '@/lib/api/context';
import { canManageCalendar } from '@/lib/permissions/permissions';
import { displayName } from '@/lib/privacy/display';
import { Card } from '@/components/ui/ui';
import { EditCalendarForm } from '@/components/admin/EditCalendarForm';
import { MemberSection } from '@/components/admin/MemberSection';
import { AppShell } from '@/components/layout/AppShell';

interface PageProps {
  params: Promise<{ id: string }>;
}

export default async function AdminCalendarPage({ params }: PageProps) {
  const { id } = await params;
  const context = await requireCalendarContext(id).catch(() => null);
  if (!context) {
    redirect('/login');
  }
  if (!canManageCalendar(context.user, context.calendar)) {
    redirect('/dashboard');
  }

  const reservations = await prisma.reservation.findMany({
    where: { calendarId: id, status: 'CONFIRMED' },
    orderBy: { startAt: 'desc' },
    take: 50,
    select: {
      id: true,
      title: true,
      startAt: true,
      endAt: true,
      user: { select: { email: true, username: true } },
    },
  });

  return (
    <AppShell role={context.user.role} userEmail={context.user.email} username={context.user.username}>
      <h1 className="text-2xl font-bold">{context.calendar.title} verwalten</h1>

      <EditCalendarForm
        calendarId={id}
        initialTitle={context.calendar.title}
        initialDescription={context.calendar.description ?? ''}
        initialTimezone={context.calendar.timezone}
        initialIsActive={context.calendar.isActive}
      />

      <Card>
        <MemberSection calendarId={id} />
      </Card>

      <Card>
        <h2 className="mb-3 text-lg font-semibold">Letzte Reservierungen</h2>
        {reservations.length === 0 ? (
          <p className="text-sm text-slate-500">Noch keine Reservierungen.</p>
        ) : (
          <ul className="space-y-2 text-sm">
            {reservations.map((reservation) => (
              <li key={reservation.id} className="rounded bg-slate-100 px-3 py-2">
                <span className="font-medium">
                  {reservation.startAt.toLocaleString('de-DE')} –{' '}
                  {reservation.endAt.toLocaleTimeString('de-DE', {
                    hour: '2-digit',
                    minute: '2-digit',
                  })}
                </span>{' '}
                {reservation.title}
                <span className="ml-2 text-xs text-slate-500">
                  {displayName(reservation.user.username, reservation.user.email)}
                </span>
              </li>
            ))}
          </ul>
        )}
      </Card>
    </AppShell>
  );
}