middleware.ts

// middleware.ts
import { createServerClient, type CookieOptions } from '@supabase/ssr'
import { NextResponse, type NextRequest } from 'next/server'

export async function middleware(request: NextRequest) {
  let response = NextResponse.next({
    request: {
      headers: request.headers,
    },
  })

  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        get(name: string) {
          return request.cookies.get(name)?.value;
        },
        set(name, value, options) {
          request.cookies.set({ name, value, ...options });
          response = NextResponse.next({
            request: {
              headers: request.headers,
            },
          });
          response.cookies.set({ name, value, ...options });
        },
        remove(name, options) {
          request.cookies.set({ name, value: '', ...options });
          response = NextResponse.next({
            request: {
              headers: request.headers,
            },
          });
          response.cookies.set({ name, value: '', ...options });
        },
      },
    }
  )

  // IMPORTANT: Avoid calling `getSession()` here, as it can lead to an infinite loop.
  // Instead, refresh the session on every request.
  // See https://supabase.com/docs/guides/auth/server-side/nextjs
  await supabase.auth.getUser();

  // If user is not signed in and tries to access a protected route, redirect to login
  const { data: { session } } = await supabase.auth.getSession()

  if (!session && !request.nextUrl.pathname.startsWith('/login') && !request.nextUrl.pathname.startsWith('/signup')) {
    const url = request.nextUrl.clone()
    url.pathname = '/login'
    return NextResponse.redirect(url)
  }

  // If user is signed in and tries to access login/signup, redirect to home
  if (session && (request.nextUrl.pathname.startsWith('/login') || request.nextUrl.pathname.startsWith('/signup'))) {
    const url = request.nextUrl.clone()
    url.pathname = '/dashboard'
    return NextResponse.redirect(url)
  }

  // If user is signed in and on the root path, redirect to the dashboard
  if (session && request.nextUrl.pathname === '/') {
    const url = request.nextUrl.clone()
    url.pathname = '/dashboard'
    return NextResponse.redirect(url)
  }

  return response
}

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)
     * Feel free to modify this pattern to include more paths.
     */
    '/((?!_next/static|_next/image|favicon.ico).*)',
  ],
}