<?php
  
  namespace App\Http\Middleware;
  
  use App\Providers\RouteServiceProvider;
  use Closure;
  use Illuminate\Support\Facades\Auth;
  
  class RedirectIfAuthenticated
  {
      /**
       * Handle an incoming request.
       *
       * @param  \Illuminate\Http\Request  $request
       * @param  \Closure  $next
       * @param  string|null  $guard
       * @return mixed
       */
      public function handle($request, Closure $next, $guard = null)
      {
          if (Auth::guard($guard)->check()) {
              return response()->json(['error' => 'Already authenticated.'], 400);
          }
  
          return $next($request);
      }
  }