middleware.ts

import { NextResponse } from 'next/server'
import type { NextRequest } from 'next/server'

export function middleware(request: NextRequest) {
  // Clone the request headers
  const requestHeaders = new Headers(request.headers)
  
  // Create response
  const response = NextResponse.next({
    request: {
      headers: requestHeaders,
    },
  })

  // Add security headers
  response.headers.set('X-Content-Type-Options', 'nosniff')
  response.headers.set('X-Frame-Options', 'DENY')
  response.headers.set('X-XSS-Protection', '1; mode=block')
  response.headers.set('Referrer-Policy', 'strict-origin-when-cross-origin')
  
  // Add CORS headers for API routes
  if (request.nextUrl.pathname.startsWith('/api/')) {
    // Allow requests from same origin (adjust as needed for your use case)
    const origin = request.headers.get('origin')
    if (origin && (
      origin === process.env.NEXT_PUBLIC_APP_URL ||
      origin.includes('localhost') ||
      origin.includes('127.0.0.1')
    )) {
      response.headers.set('Access-Control-Allow-Origin', origin)
      response.headers.set('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS')
      response.headers.set('Access-Control-Allow-Headers', 'Content-Type, Authorization')
      response.headers.set('Access-Control-Allow-Credentials', 'true')
    }
  }

  return response
}

// Configure which routes the middleware should run on
export const config = {
  matcher: [
    /*
     * Match all request paths except for the ones starting with:
     * - _next/static (static files)
     * - _next/image (image optimization files)
     * - favicon.ico (favicon file)
     * - public folder
     */
    '/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
  ],
}