import { NextResponse, type NextRequest } from "next/server";
import { slugifyFa } from "@/lib/slugify";
import { TENANT_DOMAIN } from "@/lib/meshkee";

const API_BASE = "https://api.meshkee.com/api/v1";

function canonicalProductPath(product: { id: string; nameFa: string }) {
  return `/products/${product.id}/${encodeURIComponent(slugifyFa(product.nameFa))}`;
}

function canonicalBlogPath(post: { id: string; nameFa?: string; titleFa?: string; title?: string }) {
  const title = post.nameFa || post.titleFa || post.title || "post";
  return `/blog/${post.id}/${encodeURIComponent(slugifyFa(title))}`;
}

async function redirectLegacyProduct(slug: string, request: NextRequest) {
  const res = await fetch(
    `${API_BASE}/tenants/${TENANT_DOMAIN}/products/${encodeURIComponent(slug)}`,
    { next: { revalidate: 300 } },
  );
  if (!res.ok) return null;
  const data = (await res.json()) as { product?: { id: string; nameFa: string } };
  const product = data.product;
  if (!product) return null;
  return NextResponse.redirect(new URL(canonicalProductPath(product), request.url), 308);
}

async function redirectLegacyBlog(slug: string, request: NextRequest) {
  const res = await fetch(
    `${API_BASE}/tenants/${TENANT_DOMAIN}/blogs/${encodeURIComponent(slug)}`,
    { next: { revalidate: 300 } },
  );
  if (!res.ok) return null;
  const data = (await res.json()) as {
    blog?: { id: string; nameFa?: string; titleFa?: string; title?: string };
    post?: { id: string; nameFa?: string; titleFa?: string; title?: string };
  };
  const post = data.blog ?? data.post;
  if (!post) return null;
  return NextResponse.redirect(new URL(canonicalBlogPath(post), request.url), 308);
}

export async function middleware(request: NextRequest) {
  const { pathname } = request.nextUrl;

  const productMatch = pathname.match(/^\/products\/([^/]+)$/);
  if (productMatch) {
    const segment = decodeURIComponent(productMatch[1]);
    if (segment !== "category" && !/^\d+$/.test(segment)) {
      const redirect = await redirectLegacyProduct(segment, request);
      if (redirect) return redirect;
    }
  }

  const blogMatch = pathname.match(/^\/blog\/([^/]+)$/);
  if (blogMatch) {
    const segment = decodeURIComponent(blogMatch[1]);
    if (!/^\d+$/.test(segment)) {
      const redirect = await redirectLegacyBlog(segment, request);
      if (redirect) return redirect;
    }
  }

  return NextResponse.next();
}

export const config = {
  matcher: ["/products/:path*", "/blog/:path*"],
};