import { clerkMiddleware, createRouteMatcher } from "@clerk/nextjs/server";
import { NextResponse } from "next/server";
import createMiddleware from "next-intl/middleware";
import { LOCALIZED_PATHNAMES } from "@/lib/localized-routes";

// Admin routes that require admin role
const isAdminRoute = createRouteMatcher(["/admin(.*)"]);

/**
 * ADMIN CONFIGURATION
 *
 * Admin access is controlled via Clerk publicMetadata.
 * To grant admin access:
 * 1. Go to Clerk Dashboard → Users → Select user
 * 2. Edit "Public metadata" → Set: { "role": "admin" }
 * 3. Save
 *
 * Session token must include metadata (configured in Clerk Dashboard → Sessions):
 * { "metadata": "{{user.public_metadata}}" }
 */

// Create the internationalization middleware
const intlMiddleware = createMiddleware({
  locales: ["ro", "en"],
  defaultLocale: "ro",
  localePrefix: "always", // Both /ro and /en will have explicit prefixes
  pathnames: LOCALIZED_PATHNAMES,
  // The pages declare hreflang themselves; next-intl's Link header disagreed
  // with them (unprefixed x-default, wrong per-locale blog slugs).
  alternateLinks: false,
});

export default clerkMiddleware(async (auth, req) => {
  const pathname = req.nextUrl.pathname;

  // Skip internationalization for admin routes, API routes, referral links
  // (/r/<slug> is a locale-less Route Handler that must not be redirected to
  // /ro/r/<slug>), and static files
  if (
    isAdminRoute(req) ||
    pathname.startsWith("/api/") ||
    pathname.startsWith("/r/") ||
    pathname.startsWith("/_next/") ||
    pathname.includes(".")
  ) {
    // Handle admin routes
    if (isAdminRoute(req)) {
      const { userId, sessionClaims } = await auth();

      // If no user is authenticated, redirect to sign-in
      if (!userId) {
        const homeUrl = new URL("/", req.url);
        return NextResponse.redirect(homeUrl);
      }

      // Check admin role from session claims (set via Clerk publicMetadata)
      const isAdmin = sessionClaims?.metadata?.role === "admin";
      if (!isAdmin) {
        const homeUrl = new URL("/", req.url);
        return NextResponse.redirect(homeUrl);
      }
    }

    return NextResponse.next();
  }

  // Apply internationalization to other routes
  return intlMiddleware(req);
});

export const config = {
  matcher: [
    // Skip Next.js internals and all static files, unless found in search params
    "/((?!_next|[^?]*\\.(?:html?|css|js(?!on)|jpe?g|webp|png|gif|svg|ttf|woff2?|ico|csv|docx?|xlsx?|zip|webmanifest)).*)",
    // Always run for API routes
    "/(api|trpc)(.*)",
  ],
};