---
import { getCollection, render } from 'astro:content';
import type { CollectionEntry } from 'astro:content';
import BlogPost from '../../layouts/BlogPost.astro';

type BlogEntry = CollectionEntry<'blog'>;
type RelatedPost = { title: string; description: string; href: string };

export async function getStaticPaths() {
  const posts = await getCollection('blog');
  const stopWords = new Set(['and', 'for', 'the', 'with', 'worldmonitor', 'world', 'monitor']);
  const tokenize = (value: string | undefined): Set<string> => new Set((value || '')
    .toLowerCase()
    .split(/[^a-z0-9]+/)
    .filter((token) => token.length > 2 && !stopWords.has(token)));
  const relatedByPost = new Map(posts.map((current) => {
    const currentTerms = tokenize(`${current.data.keywords}, ${current.data.audience}, ${current.data.title}`);
    const relatedPosts: RelatedPost[] = posts
      .filter((post) => post.id !== current.id)
      .map((post) => {
        const candidateTerms = tokenize(`${post.data.keywords}, ${post.data.audience}, ${post.data.title}`);
        let score = 0;
        for (const term of candidateTerms) {
          if (currentTerms.has(term)) score += 1;
        }
        if (post.data.audience === current.data.audience) score += 2;
        return { post, score };
      })
      .sort((a, b) => b.score - a.score || b.post.data.pubDate.valueOf() - a.post.data.pubDate.valueOf())
      .slice(0, 3)
      .map(({ post }) => ({
        title: post.data.title,
        description: post.data.description,
        href: `/blog/posts/${post.id}/`,
      }));
    return [current.id, relatedPosts];
  }));
  return posts.map((post) => ({
    params: { id: post.id },
    props: { post, relatedPosts: relatedByPost.get(post.id) ?? [] },
  }));
}

const { post, relatedPosts } = Astro.props as { post: BlogEntry; relatedPosts: RelatedPost[] };
const { Content } = await render(post);
---

<BlogPost
  title={post.data.title}
  description={post.data.description}
  metaTitle={post.data.metaTitle}
  keywords={post.data.keywords}
  pubDate={post.data.pubDate}
  modifiedDate={post.data.modifiedDate}
  author={post.data.author}
  authorUrl={post.data.authorUrl}
  authorBio={post.data.authorBio}
  audience={post.data.audience}
  heroImage={post.data.heroImage}
  slug={post.id}
  rawBody={post.body}
  relatedPosts={relatedPosts}
>
  <Content />
</BlogPost>