import { MetadataRoute } from 'next';

const siteUrl = process.env.NEXT_PUBLIC_SITE_URL || 'https://spanglish.com.py';
const apiUrl = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3001';

interface SitemapEvent {
  id: string;
  status: string;
  startDatetime: string;
  updatedAt: string;
}

/**
 * Fetch all indexable events: published, completed, and cancelled.
 * Sold-out / past events stay in the index (marked as expired, not removed).
 * Only draft and archived events are excluded.
 */
async function getIndexableEvents(): Promise<SitemapEvent[]> {
  try {
    const [publishedRes, completedRes] = await Promise.all([
      fetch(`${apiUrl}/api/events?status=published`, {
        next: { tags: ['events-sitemap'] },
      }),
      fetch(`${apiUrl}/api/events?status=completed`, {
        next: { tags: ['events-sitemap'] },
      }),
    ]);

    const published = publishedRes.ok
      ? ((await publishedRes.json()).events as SitemapEvent[]) || []
      : [];
    const completed = completedRes.ok
      ? ((await completedRes.json()).events as SitemapEvent[]) || []
      : [];

    return [...published, ...completed];
  } catch {
    return [];
  }
}

export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
  const events = await getIndexableEvents();
  const now = new Date();

  // Static pages
  const staticPages: MetadataRoute.Sitemap = [
    {
      url: siteUrl,
      lastModified: now,
      changeFrequency: 'weekly',
      priority: 1,
    },
    {
      url: `${siteUrl}/events`,
      lastModified: now,
      changeFrequency: 'daily',
      priority: 0.9,
    },
    {
      url: `${siteUrl}/community`,
      lastModified: now,
      changeFrequency: 'monthly',
      priority: 0.7,
    },
    {
      url: `${siteUrl}/contact`,
      lastModified: now,
      changeFrequency: 'monthly',
      priority: 0.6,
    },
    {
      url: `${siteUrl}/faq`,
      lastModified: now,
      changeFrequency: 'monthly',
      priority: 0.6,
    },
    // Legal pages
    {
      url: `${siteUrl}/legal/terms-policy`,
      lastModified: now,
      changeFrequency: 'yearly',
      priority: 0.3,
    },
    {
      url: `${siteUrl}/legal/privacy-policy`,
      lastModified: now,
      changeFrequency: 'yearly',
      priority: 0.3,
    },
    {
      url: `${siteUrl}/legal/refund-cancelation-policy`,
      lastModified: now,
      changeFrequency: 'yearly',
      priority: 0.3,
    },
  ];

  // Dynamic event pages — upcoming events get higher priority
  const eventPages: MetadataRoute.Sitemap = events.map((event) => {
    const isUpcoming = new Date(event.startDatetime) > now;
    return {
      url: `${siteUrl}/events/${event.id}`,
      lastModified: new Date(event.updatedAt),
      changeFrequency: isUpcoming ? ('weekly' as const) : ('monthly' as const),
      priority: isUpcoming ? 0.8 : 0.5,
    };
  });

  return [...staticPages, ...eventPages];
}