middleware.ts

/**
 * ObjectDocs
 * Copyright (c) 2026-present ObjectStack Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import { createI18nMiddleware } from 'fumadocs-core/i18n/middleware';
import { i18n } from '@/lib/i18n';
import { NextResponse, NextRequest, NextFetchEvent } from 'next/server';

// Create fumadocs middleware
const fumadocsMiddleware = createI18nMiddleware(i18n);

export default function middleware(request: NextRequest, event: NextFetchEvent) {
  const path = request.nextUrl.pathname;
  
  // Handle root path separately with custom language detection
  if (path === '/') {
    const acceptLanguage = request.headers.get('accept-language') || '';
    
    // Simple language detection: check if zh is in Accept-Language
    if (acceptLanguage.toLowerCase().includes('zh')) {
      // Redirect to Chinese docs
      const url = request.nextUrl.clone();
      url.pathname = '/cn/docs';
      return NextResponse.redirect(url);
    } else {
      // Redirect to default language (English)
      const url = request.nextUrl.clone();
      url.pathname = '/en/docs';
      return NextResponse.redirect(url);
    }
  }
  
  // For all other paths, pass through to fumadocs middleware
  return fumadocsMiddleware(request, event);
}

export const config = {
  // Matcher ignoring `/_next/`, `/api/`, LLM routes, OG image routes, and SEO files
  matcher: ['/((?!api|_next/static|_next/image|favicon.ico|logo.svg|llms\\.txt|llms-full\\.txt|llms\\.mdx|og/|sitemap\\.xml|robots\\.txt).*)'],
};