Form submit intercepted by auth middleware in laravel 5

I 've been working on a laravel 5.7 blog project. I want to comment an article. I need to achieve this:

• Before logging in, I can type anything in comment textarea.

• I submit comment(of course it would be intercepted by auth middleware),

• then I'm redirected to login page,

• After logging in, **I hope my app could submit previous form data(or comment) automaticlly instead of typing the same comment again.

• I think that's a very common bussiness logic in many websites nowdays, but how am I supposed to achieve this?

My comments controller here:

public function __construct()
{
    $this->middleware('auth');
}

public function store(Post $post){
    $comment = Comment::create([
        'body' => session('comment')?:request('body'),
        'post_id'  => $post->id,
        'user_id' => auth()->user()->id 
    //before logging in, you don't have an user_id yet.
    ]);        
    return back()->with('success', 'Add comment succeeded');
}

web.php Route here:

Route::post('/posts/{post}/comments', 'CommentsController@store')->name('addComment');

Basiclly auth middleware intercepted my form data submit, I want to go across the auth middleware with my form data. Not lost them after logging in.

via Chebli Mohamed