import { postBySlugQuery, postSlugsQuery, urlFor } from '@/lib/sanity'
import { sanityFetch } from '@/lib/sanityFetch'
import { PortableTextRenderer } from '@/components/PortableTextRenderer'
import Image from 'next/image'
import Link from 'next/link'
import { notFound } from 'next/navigation'
import type { Metadata } from 'next'

export const revalidate = 60

type Params = { slug: string }

type Post = {
  _id: string
  title: string
  slug: { current: string }
  publishedAt: string
  excerpt: string | null
  mainImage: { asset: object; alt?: string } | null
  body: unknown[]
  seoTitle: string | null
  seoDescription: string | null
  author: { name: string; image?: object; bio?: string } | null
}

export async function generateStaticParams() {
  try {
    const slugs: { slug: string }[] = await sanityFetch<{ slug: string }[]>(postSlugsQuery)
    return slugs.map((s) => ({ slug: s.slug }))
  } catch (err) {
    console.error('[Guides] generateStaticParams fetch failed:', err)
    return []
  }
}

export async function generateMetadata({ params }: { params: Promise<Params> }): Promise<Metadata> {
  const { slug } = await params
  let post: Post | null = null
  try {
    post = await sanityFetch<Post | null>(postBySlugQuery, { slug })
  } catch (err) {
    console.error('[Guides] generateMetadata fetch failed:', err)
  }
  if (!post) return {}

  return {
    title: post.seoTitle ?? post.title,
    description: post.seoDescription ?? post.excerpt ?? undefined,
    openGraph: {
      title: post.seoTitle ?? post.title,
      description: post.seoDescription ?? post.excerpt ?? undefined,
      images: post.mainImage?.asset
        ? [{ url: urlFor(post.mainImage).width(1200).height(630).url() }]
        : [],
    },
  }
}

function formatDate(iso: string) {
  return new Date(iso).toLocaleDateString('en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  })
}

export default async function PostPage({ params }: { params: Promise<Params> }) {
  const { slug } = await params
  let post: Post | null = null
  try {
    post = await sanityFetch<Post | null>(postBySlugQuery, { slug })
  } catch (err) {
    console.error('[Guides] PostPage fetch failed:', err)
  }

  if (!post) notFound()

  return (
    <main className="mx-auto max-w-3xl px-4 py-10">
      {/* Breadcrumb */}
      <nav className="mb-6 text-xs text-zinc-500">
        <Link href="/guides" className="hover:text-zinc-300">
          ← Guides
        </Link>
      </nav>

      {/* Header */}
      <header className="mb-8">
        <div className="mb-3 flex items-center gap-2 text-[0.7rem] text-zinc-500">
          {post.author?.name && <span>{post.author.name}</span>}
          {post.author?.name && <span>·</span>}
          <time dateTime={post.publishedAt}>{formatDate(post.publishedAt)}</time>
        </div>

        <h1 className="text-3xl font-semibold leading-tight tracking-tight text-zinc-100 md:text-4xl">
          {post.title}
        </h1>

        {post.excerpt && (
          <p className="mt-4 text-base text-zinc-400 leading-relaxed">
            {post.excerpt}
          </p>
        )}
      </header>

      {/* Hero image */}
      {post.mainImage?.asset && (
        <div className="relative mb-10 h-64 w-full overflow-hidden rounded-xl md:h-80">
          <Image
            src={urlFor(post.mainImage).width(1200).height(630).url()}
            alt={post.mainImage.alt ?? post.title}
            fill
            priority
            className="object-cover"
            sizes="(max-width: 768px) 100vw, 768px"
          />
        </div>
      )}

      {/* Body */}
      {post.body && (
        <article className="border-b border-zinc-800 pb-10">
          <PortableTextRenderer value={post.body} />
        </article>
      )}

      {/* CTA footer */}
      <div className="mt-10 rounded-xl border border-zinc-800 bg-zinc-950/60 p-6 text-center">
        <p className="text-sm font-medium text-zinc-200">
          Ready to put this into practice?
        </p>
        <p className="mt-1 text-xs text-zinc-500">
          Use the Battl Builder to price out your parts and track your total.
        </p>
        <Link
          href="/builder"
          className="mt-4 inline-block rounded-md bg-amber-400 px-5 py-2.5 text-sm font-semibold text-black hover:bg-amber-300 transition-colors"
        >
          Start Your Build →
        </Link>
      </div>

      {/* Back link */}
      <div className="mt-8 text-center">
        <Link href="/guides" className="text-xs text-zinc-500 hover:text-zinc-300">
          ← Back to all guides
        </Link>
      </div>
    </main>
  )
}