import { notFound, redirect } from 'next/navigation';
import JsonLd from '@/components/JsonLd';
import { SITE_URL } from '@/lib/schema';
import {
  getPostBySlug,
  getAdjacentPosts,
  getReadingTime,
  extractLexicalHeadings,
  getPostSlugs,
} from '@/lib/blog';
import { Metadata } from 'next';
import Link from 'next/link';
import Image from 'next/image';
import PostNavigation from '@/components/blog/PostNavigation';
import PowerCTA from '@/components/blog/PowerCTA';
import TableOfContents from '@/components/blog/TableOfContents';
import { Heading } from '@/components/ui';
import { setRequestLocale } from 'next-intl/server';
import BlogEngagementTracker from '@/components/analytics/BlogEngagementTracker';

// Payload CMS Imports
import PayloadRichText from '@/components/PayloadRichText';

interface BlogPostProps {
  params: Promise<{
    locale: string;
    slug: string;
  }>;
}

export async function generateMetadata({ params }: BlogPostProps): Promise<Metadata> {
  const { locale, slug } = await params;
  const post = await getPostBySlug(slug, locale);

  if (!post) return {};

  const slugs = await getPostSlugs(slug, locale);
  const deSlug = slugs?.de || post.slug;
  const enSlug = slugs?.en || post.slug;

  const description = post.frontmatter.excerpt || '';
  return {
    title: post.frontmatter.title,
    description: description,
    alternates: {
      canonical: `${SITE_URL}/${locale}/blog/${post.slug}`,
      languages: {
        de: `${SITE_URL}/de/blog/${deSlug}`,
        en: `${SITE_URL}/en/blog/${enSlug}`,
        'x-default': `${SITE_URL}/en/blog/${enSlug}`,
      },
    },
    openGraph: {
      title: `${post.frontmatter.title} | KLZ Cables`,
      description: description,
      type: 'article',
      publishedTime: post.frontmatter.date,
      authors: ['KLZ Cables'],
      url: `${SITE_URL}/${locale}/blog/${post.slug}`,
    },
    twitter: {
      card: 'summary_large_image',
      title: `${post.frontmatter.title} | KLZ Cables`,
      description: description,
    },
  };
}

export default async function BlogPost({ params }: BlogPostProps) {
  const { locale, slug } = await params;
  setRequestLocale(locale);
  const post = await getPostBySlug(slug, locale);

  if (!post) {
    notFound();
  }

  // If the user accessed this post using a slug from a different locale
  // (e.g. via the generic language switcher), redirect them to the correct localized slug URL
  if (post.slug && post.slug !== slug) {
    redirect(`/${locale}/blog/${post.slug}`);
  }

  const { prev, next, isPrevRandom, isNextRandom } = await getAdjacentPosts(post.slug, locale);

  // Convert Lexical content into a plain string to estimate reading time roughly
  // Extract headings for TOC
  const headings = extractLexicalHeadings(post.content?.root || post.content);

  // Convert Lexical content into a plain string to estimate reading time roughly
  const rawTextContent = JSON.stringify(post.content);

  return (
    <article className="bg-white min-h-screen font-sans selection:bg-primary/10 selection:text-primary">
      <BlogEngagementTracker
        title={post.frontmatter.title}
        slug={slug}
        category={post.frontmatter.category}
        readingTime={getReadingTime(rawTextContent)}
      />

      {/* Featured Image Header */}
      {post.frontmatter.featuredImage ? (
        <div className="relative w-full h-[70vh] min-h-[500px] overflow-hidden group">
          <div className="absolute inset-0 transition-transform duration-[3s] ease-out scale-110 group-hover:scale-100">
            <Image
              src={post.frontmatter.featuredImage.split('?')[0]}
              alt={post.frontmatter.title}
              fill
              priority
              quality={100}
              className="object-cover"
              sizes="100vw"
              style={{
                objectPosition: `${post.frontmatter.focalX ?? 50}% ${post.frontmatter.focalY ?? 50}%`,
              }}
            />
          </div>
          <div className="absolute inset-0 bg-gradient-to-t from-neutral-dark/90 via-neutral-dark/40 to-transparent" />

          {/* Title overlay on image */}
          <div className="absolute inset-0 flex flex-col justify-end pb-16 md:pb-24">
            <div className="container mx-auto px-4">
              <div className="max-w-4xl">
                {post.frontmatter.category && (
                  <div className="overflow-hidden mb-6">
                    <span className="inline-block px-4 py-1.5 bg-accent text-neutral-dark text-xs font-bold uppercase tracking-[0.2em] rounded-sm">
                      {post.frontmatter.category}
                    </span>
                  </div>
                )}
                <Heading level={1} className="text-white mb-8 drop-shadow-2xl">
                  {post.frontmatter.title}
                </Heading>
                <div className="flex flex-wrap items-center gap-6 text-white/80 text-sm md:text-base font-medium">
                  <time dateTime={post.frontmatter.date} suppressHydrationWarning>
                    {new Date(post.frontmatter.date).toLocaleDateString(locale || 'de', {
                      year: 'numeric',
                      month: 'long',
                      day: 'numeric',
                    })}
                  </time>
                  <span className="w-1 h-1 bg-white/30 rounded-full" />
                  <span>{getReadingTime(rawTextContent)} min read</span>
                  {(new Date(post.frontmatter.date) > new Date() ||
                    post.frontmatter.public === false) && (
                    <>
                      <span className="w-1 h-1 bg-white/30 rounded-full" />
                      <span className="px-2 py-0.5 border border-white/40 text-white/80 rounded uppercase tracking-widest text-[10px] md:text-xs font-bold">
                        Draft Preview
                      </span>
                    </>
                  )}
                </div>
              </div>
            </div>
          </div>
        </div>
      ) : (
        <header className="pt-32 pb-16 bg-neutral-50 border-b border-neutral-100">
          <div className="container mx-auto px-4 max-w-4xl">
            {post.frontmatter.category && (
              <div className="mb-6">
                <span className="inline-block px-4 py-1.5 bg-primary/10 text-primary text-xs font-bold uppercase tracking-[0.2em] rounded-sm">
                  {post.frontmatter.category}
                </span>
              </div>
            )}
            <Heading level={1} className="mb-8">
              {post.frontmatter.title}
            </Heading>
            <div className="flex items-center gap-6 text-text-primary/80 font-medium">
              <time dateTime={post.frontmatter.date} suppressHydrationWarning>
                {new Date(post.frontmatter.date).toLocaleDateString(locale || 'de', {
                  year: 'numeric',
                  month: 'long',
                  day: 'numeric',
                })}
              </time>
              <span className="w-1 h-1 bg-neutral-400 rounded-full" />
              <span>{getReadingTime(rawTextContent)} min read</span>
              {(new Date(post.frontmatter.date) > new Date() ||
                post.frontmatter.public === false) && (
                <>
                  <span className="w-1 h-1 bg-neutral-300 rounded-full" />
                  <span className="px-2 py-0.5 border border-orange-500/50 text-orange-600 rounded uppercase tracking-widest text-[10px] md:text-xs font-bold">
                    Draft Preview
                  </span>
                </>
              )}
            </div>
          </div>
        </header>
      )}

      {/* Main Content Area with Sticky Narrative Layout */}
      <div className="container mx-auto px-4 py-16 md:py-24">
        <div className="sticky-narrative-container">
          {/* Left Column: Content */}
          <div className="sticky-narrative-content">
            {/* Excerpt/Lead paragraph if available */}
            {post.frontmatter.excerpt && (
              <div className="mb-16">
                <p className="text-xl md:text-2xl text-text-primary leading-relaxed font-medium border-l-4 border-primary pl-8 py-2 italic">
                  {post.frontmatter.excerpt}
                </p>
              </div>
            )}

            {/* Main content with enhanced styling rendering Payload Lexical */}
            <div className="prose prose-lg md:prose-xl max-w-none prose-headings:font-bold prose-headings:text-text-primary prose-p:text-text-secondary prose-p:leading-relaxed prose-a:text-primary prose-a:no-underline hover:prose-a:underline prose-img:rounded-2xl prose-img:shadow-2xl prose-blockquote:border-primary prose-blockquote:bg-primary/5 prose-blockquote:rounded-r-2xl prose-strong:text-primary">
              <PayloadRichText data={post.content} />
            </div>

            {/* Power CTA */}
            <div className="mt-24 animate-slight-fade-in-from-bottom">
              <PowerCTA locale={locale} />
            </div>

            {/* Post Navigation */}
            <div className="mt-16">
              <PostNavigation
                prev={prev}
                next={next}
                isPrevRandom={isPrevRandom}
                isNextRandom={isNextRandom}
                locale={locale}
              />
            </div>

            {/* Back to blog link */}
            <div className="mt-16 pt-10 border-t border-neutral-100">
              <Link
                href={`/${locale}/blog`}
                className="inline-flex items-center gap-3 text-text-secondary hover:text-primary font-bold text-sm uppercase tracking-widest transition-all group"
              >
                <svg
                  className="w-5 h-5 transition-transform group-hover:-translate-x-2"
                  fill="none"
                  stroke="currentColor"
                  viewBox="0 0 24 24"
                >
                  <path
                    strokeLinecap="round"
                    strokeLinejoin="round"
                    strokeWidth={2}
                    d="M15 19l-7-7 7-7"
                  />
                </svg>
                {locale === 'de' ? 'Zurück zur Übersicht' : 'Back to Overview'}
              </Link>
            </div>
          </div>

          {/* Right Column: Sticky Sidebar - TOC */}
          <aside className="sticky-narrative-sidebar hidden lg:block">
            <div className="space-y-12 lg:sticky lg:top-32">
              <TableOfContents headings={headings} locale={locale} />
            </div>
          </aside>
        </div>
      </div>

      {/* Structured Data */}
      <JsonLd
        id={`jsonld-${slug}`}
        data={
          {
            '@context': 'https://schema.org',
            '@type': 'BlogPosting',
            headline: post.frontmatter.title,
            datePublished: post.frontmatter.date,
            dateModified: post.frontmatter.date,
            image: post.frontmatter.featuredImage
              ? `${SITE_URL}${post.frontmatter.featuredImage}`
              : undefined,
            author: {
              '@type': 'Organization',
              name: 'KLZ Cables',
              url: SITE_URL,
              logo: `${SITE_URL}/logo-blue.svg`,
            },
            publisher: {
              '@type': 'Organization',
              name: 'KLZ Cables',
              logo: {
                '@type': 'ImageObject',
                url: `${SITE_URL}/logo-blue.svg`,
              },
            },
            description: post.frontmatter.excerpt,
            mainEntityOfPage: {
              '@type': 'WebPage',
              '@id': `${SITE_URL}/${locale}/blog/${slug}`,
            },
            articleSection: post.frontmatter.category,
            wordCount: rawTextContent.split(/\s+/).length,
            timeRequired: `PT${getReadingTime(rawTextContent)}M`,
          } as any
        }
      />
      <JsonLd
        id={`breadcrumb-${slug}`}
        data={
          {
            '@context': 'https://schema.org',
            '@type': 'BreadcrumbList',
            itemListElement: [
              {
                '@type': 'ListItem',
                position: 1,
                name: 'Blog',
                item: `${SITE_URL}/${locale}/blog`,
              },
              {
                '@type': 'ListItem',
                position: 2,
                name: post.frontmatter.title,
                item: `${SITE_URL}/${locale}/blog/${slug}`,
              },
            ],
          } as any
        }
      />
    </article>
  );
}