import Link from 'next/link';

import {
  CalendarDays,
  ChevronLeft,
  ChevronRight,
  MapPin,
  Plus,
  Users,
} from 'lucide-react';
import { getTranslations } from 'next-intl/server';

import { createEventManagementApi } from '@kit/event-management/api';
import { formatDate } from '@kit/shared/dates';
import { getSupabaseServerClient } from '@kit/supabase/server-client';
import { Badge } from '@kit/ui/badge';
import { Button } from '@kit/ui/button';
import { Card, CardContent, CardHeader, CardTitle } from '@kit/ui/card';

import { AccountNotFound } from '~/components/account-not-found';
import { CmsPageShell } from '~/components/cms-page-shell';
import { EmptyState } from '~/components/empty-state';
import { StatsCard } from '~/components/stats-card';
import { EVENT_STATUS_VARIANT, EVENT_STATUS_LABEL } from '~/lib/status-badges';

interface PageProps {
  params: Promise<{ account: string }>;
  searchParams: Promise<Record<string, string | string[] | undefined>>;
}

export default async function EventsPage({ params, searchParams }: PageProps) {
  const { account } = await params;
  const search = await searchParams;
  const client = getSupabaseServerClient();
  const t = await getTranslations('cms.events');

  const { data: acct } = await client
    .from('accounts')
    .select('id')
    .eq('slug', account)
    .single();

  if (!acct) return <AccountNotFound />;

  const page = Number(search.page) || 1;
  const api = createEventManagementApi(client);
  const events = await api.listEvents(acct.id, { page });

  // Fetch registration counts for all events on this page
  const eventIds = events.data.map((eventItem: Record<string, unknown>) =>
    String(eventItem.id),
  );
  const registrationCounts = await api.getRegistrationCounts(eventIds);

  // Pre-compute stats before rendering
  const uniqueLocationCount = new Set(
    events.data
      .map((eventItem: Record<string, unknown>) => eventItem.location)
      .filter(Boolean),
  ).size;

  const totalCapacity = events.data.reduce(
    (sum: number, eventItem: Record<string, unknown>) =>
      sum + (Number(eventItem.capacity) || 0),
    0,
  );

  return (
    <CmsPageShell account={account} title={t('title')}>
      <div className="flex w-full flex-col gap-6">
        {/* Header */}
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-2xl font-bold">{t('title')}</h1>
            <p className="text-muted-foreground">{t('description')}</p>
          </div>

          <Link href={`/home/${account}/events/new`}>
            <Button data-test="events-new-btn">
              <Plus className="mr-2 h-4 w-4" />
              {t('newEvent')}
            </Button>
          </Link>
        </div>

        {/* Stats */}
        <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
          <StatsCard
            title={t('title')}
            value={events.total}
            icon={<CalendarDays className="h-5 w-5" />}
          />
          <StatsCard
            title={t('locations')}
            value={uniqueLocationCount}
            icon={<MapPin className="h-5 w-5" />}
          />
          <StatsCard
            title={t('totalCapacity')}
            value={totalCapacity}
            icon={<Users className="h-5 w-5" />}
          />
        </div>

        {/* Table or Empty State */}
        {events.data.length === 0 ? (
          <EmptyState
            icon={<CalendarDays className="h-8 w-8" />}
            title={t('noEvents')}
            description={t('noEventsDescription')}
            actionLabel={t('newEvent')}
            actionHref={`/home/${account}/events/new`}
          />
        ) : (
          <Card>
            <CardHeader>
              <CardTitle>
                {t('allEvents')} ({events.total})
              </CardTitle>
            </CardHeader>
            <CardContent>
              <div className="rounded-md border">
                <table className="w-full text-sm">
                  <thead>
                    <tr className="bg-muted/50 border-b">
                      <th className="p-3 text-left font-medium">{t('name')}</th>
                      <th className="p-3 text-left font-medium">
                        {t('eventDate')}
                      </th>
                      <th className="p-3 text-left font-medium">
                        {t('eventLocation')}
                      </th>
                      <th className="p-3 text-right font-medium">
                        {t('capacity')}
                      </th>
                      <th className="p-3 text-left font-medium">
                        {t('status')}
                      </th>
                      <th className="p-3 text-right font-medium">
                        {t('registrations')}
                      </th>
                    </tr>
                  </thead>
                  <tbody>
                    {events.data.map((event: Record<string, unknown>) => {
                      const eventId = String(event.id);
                      const regCount = registrationCounts[eventId] ?? 0;

                      return (
                        <tr
                          key={eventId}
                          className="hover:bg-muted/30 border-b"
                        >
                          <td className="p-3 font-medium">
                            <Link
                              href={`/home/${account}/events/${eventId}`}
                              className="hover:underline"
                            >
                              {String(event.name)}
                            </Link>
                          </td>
                          <td className="p-3">
                            {formatDate(event.event_date as string)}
                          </td>
                          <td className="p-3">
                            {String(event.location ?? '—')}
                          </td>
                          <td className="p-3 text-right">
                            {event.capacity != null
                              ? String(event.capacity)
                              : '—'}
                          </td>
                          <td className="p-3">
                            <Badge
                              variant={
                                EVENT_STATUS_VARIANT[String(event.status)] ??
                                'secondary'
                              }
                            >
                              {EVENT_STATUS_LABEL[String(event.status)] ??
                                String(event.status)}
                            </Badge>
                          </td>
                          <td className="p-3 text-right font-medium">
                            {regCount}
                          </td>
                        </tr>
                      );
                    })}
                  </tbody>
                </table>
              </div>

              {/* Pagination */}
              {events.totalPages > 1 && (
                <div className="flex items-center justify-between pt-4">
                  <span className="text-muted-foreground text-sm">
                    {t('paginationPage', {
                      page: events.page,
                      totalPages: events.totalPages,
                    })}
                  </span>
                  <div className="flex gap-2">
                    {events.page > 1 && (
                      <Link
                        href={`/home/${account}/events?page=${events.page - 1}`}
                      >
                        <Button variant="outline" size="sm">
                          <ChevronLeft className="mr-1 h-4 w-4" />
                          {t('paginationPrevious')}
                        </Button>
                      </Link>
                    )}
                    {events.page < events.totalPages && (
                      <Link
                        href={`/home/${account}/events?page=${events.page + 1}`}
                      >
                        <Button variant="outline" size="sm">
                          {t('paginationNext')}
                          <ChevronRight className="ml-1 h-4 w-4" />
                        </Button>
                      </Link>
                    )}
                  </div>
                </div>
              )}
            </CardContent>
          </Card>
        )}
      </div>
    </CmsPageShell>
  );
}
