import { MetadataRoute } from 'next';
import { getCategories, getProducts, getArticlesResult } from '../lib/cms';

const baseUrl = process.env.NEXT_PUBLIC_SITE_URL || 'http://localhost:3000';

const languages = ['th', 'en', 'ja', 'zh', 'vi', 'ko'];

function createAlternates(path: string) {
  const alternates: Record<string, string> = {};
  for (const lang of languages) {
    alternates[lang] = `${baseUrl}/${lang}${path}`;
  }
  return alternates;
}

export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
  const [categories, products, articlesResult] = await Promise.all([
    getCategories(),
    getProducts('limit=1000'),
    getArticlesResult(),
  ]);

  const staticPages = [
    '',
    '/shop',
    '/scent-guide',
    '/about',
    '/contact',
    '/faq',
  ];

  const routes: MetadataRoute.Sitemap = staticPages.map((route) => ({
    url: `${baseUrl}/th${route}`,
    lastModified: new Date(),
    changeFrequency: 'daily',
    priority: route === '' ? 1 : 0.8,
    alternates: {
      languages: createAlternates(route),
    },
  }));

  const categoryRoutes: MetadataRoute.Sitemap = categories.map((category) => ({
    url: `${baseUrl}/th/category/${category.id}`,
    lastModified: new Date(),
    changeFrequency: 'weekly',
    priority: 0.7,
    alternates: {
      languages: createAlternates(`/category/${category.id}`),
    },
  }));

  const productRoutes: MetadataRoute.Sitemap = products.map((product) => ({
    url: `${baseUrl}/th/products/${product.id}`,
    lastModified: new Date(),
    changeFrequency: 'daily',
    priority: 0.9,
    alternates: {
      languages: createAlternates(`/products/${product.id}`),
    },
  }));

  const articleRoutes: MetadataRoute.Sitemap = [];
  if (articlesResult.ok && articlesResult.data) {
    articlesResult.data.forEach((article) => {
      articleRoutes.push({
        url: `${baseUrl}/th/article/${article.slug}`,
        lastModified: new Date(article.updatedAt || article.createdAt),
        changeFrequency: 'monthly',
        priority: 0.6,
        alternates: {
          languages: createAlternates(`/article/${article.slug}`),
        },
      });
    });
  }

  return [...routes, ...categoryRoutes, ...productRoutes, ...articleRoutes];
}