// app/blog/[slug]/page.tsx. Prerendered post with metadata and Article JSON-LD. Placeholder values: replace every one.
// Built on next@16.4.0 (route shows as SSG) and passed tsc --noEmit. Assumes lib/posts.ts and lib/site.ts exist.
import type { Metadata } from 'next'
import { notFound } from 'next/navigation'
import { getPost, getPosts } from '@/lib/posts'
import { SITE_URL } from '@/lib/site'
import { jsonLd } from '@/lib/json-ld'

type Props = { params: Promise<{ slug: string }> }

// Prerender every post at build time so the full article is in the HTML response.
export async function generateStaticParams() {
  return (await getPosts()).map((p) => ({ slug: p.slug }))
}

export async function generateMetadata({ params }: Props): Promise<Metadata> {
  const { slug } = await params
  const post = await getPost(slug)
  if (!post) return {}
  return {
    title: post.title,
    description: post.description,
    alternates: { canonical: `/blog/${post.slug}` },
    openGraph: {
      type: 'article',
      title: post.title,
      description: post.description,
      url: `/blog/${post.slug}`,
      publishedTime: post.publishedAt,
      modifiedTime: post.updatedAt ?? post.publishedAt,
    },
  }
}

export default async function Page({ params }: Props) {
  const { slug } = await params
  const post = await getPost(slug)
  if (!post) notFound()

  const article = {
    '@context': 'https://schema.org',
    '@type': 'Article',
    headline: post.title,
    description: post.description,
    datePublished: post.publishedAt,
    dateModified: post.updatedAt ?? post.publishedAt,
    author: { '@type': 'Person', name: post.author },
    publisher: { '@id': `${SITE_URL}/#organization` },
    mainEntityOfPage: `${SITE_URL}/blog/${post.slug}`,
  }

  return (
    <article>
      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: jsonLd(article) }} />
      <h1>{post.title}</h1>
      <p>{post.description}</p>
      <div>{post.body}</div>
    </article>
  )
}