---
import BaseLayout from "@/layouts/BaseLayout.astro";
import { getCollection } from "astro:content";
import Headline from "@/components/ui/Headline.astro";
import PostItem from "@/components/blog/PostItem.astro";
import Pagination from "@/components/ui/Pagination.astro";
import type { Page } from "astro";
import type { CollectionEntry } from "astro:content";
import {
  categoryMap,
  getCategoryPath,
  type TaxonomyItem,
} from "@/utils/taxonomy";

export async function getStaticPaths() {
  const PAGE_SIZE = 6;
  const allPosts = await getCollection("blog");
  const posts = allPosts.filter((post) => post.data && post.data.pubDate);

  const catSlugs = new Set<string>();
  posts.forEach((post) =>
    post.data.categories?.forEach((c) => catSlugs.add(c)),
  );

  return Array.from(catSlugs).flatMap((slug) => {
    const catPosts = posts
      .filter((post) => post.data.categories?.includes(slug))
      .sort((a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf());

    const fullPath = getCategoryPath(slug);
    const cat = categoryMap.get(slug) ?? ({ slug, name: slug } as TaxonomyItem);
    const totalPages = Math.max(1, Math.ceil(catPosts.length / PAGE_SIZE));

    return Array.from({ length: totalPages }, (_, i) => {
      const pageNum = i + 1;
      return {
        params: { rest: pageNum === 1 ? fullPath : `${fullPath}/${pageNum}` },
        props: {
          cat,
          fullPath,
          posts: catPosts.slice(i * PAGE_SIZE, (i + 1) * PAGE_SIZE),
          currentPage: pageNum,
          lastPage: totalPages,
          total: catPosts.length,
          prevUrl:
            pageNum === 1
              ? undefined
              : pageNum === 2
                ? `/category/${fullPath}`
                : `/category/${fullPath}/${pageNum - 1}`,
          nextUrl:
            pageNum === totalPages
              ? undefined
              : `/category/${fullPath}/${pageNum + 1}`,
        },
      };
    });
  });
}

const { cat, posts, currentPage, lastPage, total, prevUrl, nextUrl } =
  Astro.props;

const page = {
  currentPage,
  lastPage,
  url: { prev: prevUrl, next: nextUrl },
} as unknown as Page<CollectionEntry<"blog">>;

const metadata = {
  title: cat.name,
  description: cat.description ?? `Các bài viết trong danh mục ${cat.name}.`,
};
---

<BaseLayout metadata={metadata}>
  <section class="relative px-4 py-8 sm:px-6 lg:px-8 md:py-12">
    <div class="relative mx-auto max-w-5xl">
      <Headline
        tagline="Category"
        title={cat.name}
        subtitle={cat.description ?? `Hiển thị ${total} bài viết.`}
        classes={{
          container: "mb-12 text-center",
          title:
            "font-heading mb-4 text-4xl font-bold tracking-tight text-foreground md:text-6xl capitalized",
          subtitle: "mx-auto max-w-3xl text-xl text-muted-foreground",
        }}
      />

      <div class="mb-8 text-center">
        <a href="/blog" class="text-primary hover:underline">← Quay lại blog</a>
      </div>

      <div class="grid gap-8 md:grid-cols-2 lg:grid-cols-3">
        {posts.map((post) => <PostItem post={post} />)}
      </div>
      <Pagination page={page} />
    </div>
  </section>
</BaseLayout>