import { NextRequest, NextResponse } from "next/server";

const locales = ["ar", "en"];
const defaultLocale = "ar";

function getLocale(request: NextRequest): string {
  const acceptLanguage = request.headers.get("accept-language");
  if (acceptLanguage) {
    const preferred = acceptLanguage
      .split(",")
      .map((lang) => lang.split(";")[0].trim().substring(0, 2))
      .find((lang) => locales.includes(lang));
    if (preferred) return preferred;
  }
  return defaultLocale;
}

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

  if (pathname.startsWith("/api")) {
    return NextResponse.next();
  }

  if (pathname.startsWith("/admin") || pathname.startsWith("/ai.admin")) {
    return NextResponse.next();
  }

  if (pathname.startsWith("/_next") || pathname.startsWith("/favicon")) {
    return NextResponse.next();
  }

  const pathnameHasLocale = locales.some(
    (locale) => pathname.startsWith(`/${locale}/`) || pathname === `/${locale}`
  );

  if (pathnameHasLocale) {
    return NextResponse.next();
  }

  if (pathname === "/sitemap.xml" || pathname === "/robots.txt") {
    return NextResponse.next();
  }

  const locale = getLocale(request);
  return NextResponse.redirect(new URL(`/${locale}${pathname}`, request.url));
}

export const config = {
  matcher: ["/((?!api|_next|favicon.ico|sitemap.xml|robots.txt).*)"],
};