canina/frontend/application/app/blog/[slug]/page.tsx

import React from "react";
import { ChevronRight, Calendar, User, Sparkles } from "lucide-react";
import Link from 'next/link';
import Image from 'next/image';
import type { Metadata } from 'next';

const API_URL = process.env.NEXT_PUBLIC_API_URL || 'https://apicanina.parsaaghayi.ir';

async function getBlog(slug: string) {
  try {
    const res = await fetch(`${API_URL}/api/blogs/${slug}`, { next: { revalidate: 60 } });
    if (!res.ok) throw new Error('Failed to fetch blog');
    const b = await res.json();
    return {
      id: b.id,
      slug: b.slug,
      title: b.title,
      excerpt: b.metaDescription || b.content.substring(0, 150).replace(/<[^>]+>/g, '') + '...',
      image: b.imageUrl,
      date: new Date(b.createdAt).toLocaleDateString('fa-IR'),
      author: b.author ? `${b.author.firstName} ${b.author.lastName}` : 'نویسنده کنینا',
      content: b.content
    };
  } catch (error) {
    console.error(error);
    return null;
  }
}

export const revalidate = 60; // ensure SSR dynamic revalidation works correctly

export async function generateMetadata({ params }: { params: Promise<{ slug: string }> }): Promise<Metadata> {
  const { slug } = await params;
  const blog = await getBlog(slug);
  if (!blog) return { title: 'مقاله یافت نشد | کنینا ایران' };
  
  const title = `${blog.title} | مجله سلامت کنینا`;
  const description = blog.excerpt.substring(0, 150).trim();

  return {
    title,
    description,
    alternates: {
      canonical: `/blog/${slug}`,
    },
    openGraph: {
      title,
      description,
      images: [blog.image],
      url: `/blog/${slug}`,
      siteName: "کنینا ایران",
      type: "article",
    }
  };
}

export default async function BlogPostPage({ params }: { params: Promise<{ slug: string }> }) {
  const { slug } = await params;
  const selectedPost = await getBlog(slug);

  if (!selectedPost) {
    return (
      <div className="min-h-[50vh] flex flex-col items-center justify-center font-vazir text-center" dir="rtl">
        <h1 className="text-3xl font-black text-medical-gray-900 mb-4">مقاله‌ای یافت نشد</h1>
        <Link href="/blog" className="text-canina-blue font-bold flex items-center gap-2">
          <ChevronRight className="w-4 h-4" />
          بازگشت به مجله سلامت
        </Link>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-medical-gray-50 pt-8 pb-20 px-4 font-vazir" dir="rtl">
      <div className="max-w-7xl mx-auto">
        <div className="flex items-center gap-2 text-[10px] font-black text-medical-gray-400 uppercase tracking-widest mb-10">
            <Link href="/" className="hover:text-canina-blue transition-colors">خانه</Link>
            <ChevronRight className="w-2.5 h-2.5" />
            <Link href="/blog" className="hover:text-canina-blue transition-colors">مجله سلامت</Link>
            <ChevronRight className="w-2.5 h-2.5" />
            <span className="text-canina-blue">{selectedPost.title}</span>
        </div>

        <div className="grid lg:grid-cols-12 gap-12">
          <div className="lg:col-span-8">
              <div className="bg-white rounded-[3.5rem] border border-medical-gray-200 shadow-2xl overflow-hidden">
                <div className="aspect-video w-full overflow-hidden relative">
                    <Image src={selectedPost.image} alt={selectedPost.title} fill className="w-full h-full object-cover" unoptimized />
                </div>
                <div className="p-12">
                    <div className="flex items-center gap-4 text-xs font-bold text-canina-blue mb-8">
                      <div className="bg-canina-blue/10 px-4 py-1.5 rounded-full uppercase tracking-widest">تحقیق بالینی</div>
                      <div className="flex items-center gap-1">
                          <Calendar className="w-4 h-4" />
                          {selectedPost.date}
                      </div>
                    </div>
                    <h1 className="text-4xl lg:text-5xl font-black text-medical-gray-900 mb-10 leading-tight">
                      {selectedPost.title}
                    </h1>
                    <div className="prose prose-lg max-w-none text-medical-gray-600 leading-[2] text-justify space-y-6">
                      <p className="font-bold text-medical-gray-900 italic text-xl border-r-4 border-canina-blue pr-6 py-2">
                          {selectedPost.excerpt}
                      </p>
                      <div className="whitespace-pre-line" dangerouslySetInnerHTML={{ __html: selectedPost.content }} />
                    </div>

                    <div className="mt-16 pt-10 border-t border-medical-gray-100 flex items-center justify-between">
                      <div className="flex items-center gap-4">
                          <div className="w-14 h-14 bg-medical-gray-100 rounded-full flex items-center justify-center text-medical-gray-400 border-2 border-white shadow-lg">
                            <User className="w-8 h-8" />
                          </div>
                          <div>
                            <div className="font-black text-medical-gray-900 text-lg">{selectedPost.author}</div>
                            <div className="font-bold text-medical-gray-400">نویسنده کنینا</div>
                          </div>
                      </div>
                      <div className="flex gap-4">
                          <button className="p-4 bg-medical-gray-100 rounded-2xl hover:bg-canina-blue hover:text-white transition-all text-medical-gray-400">
                            <Sparkles className="w-6 h-6" />
                          </button>
                      </div>
                    </div>
                </div>
              </div>
          </div>
          
          <div className="lg:col-span-4 space-y-10">
              <div className="bg-canina-blue rounded-[3rem] p-10 text-white shadow-2xl relative overflow-hidden">
                <div className="absolute top-0 left-0 p-8 opacity-10">
                    <Sparkles className="w-20 h-20" />
                </div>
                <h4 className="text-2xl font-black mb-6 italic relative z-10">ارتباط با کارشناسان</h4>
                <div className="space-y-6 relative z-10 text-white/90">
                    برای دریافت مشاوره تخصصی و انتخاب بهترین مکمل برای حیوان خانگی خود، با ما در تماس باشید.
                </div>
              </div>
          </div>
        </div>
      </div>
    </div>
  );
}