public function show($id)
 {
     $activity = Activity::findOrFail($id);
     $activity->load('members.user');
     $activity->load('comments.user');
     $user = [];
     $joined = false;
     $member = null;
     if (Auth::check()) {
         $user = User::findOrFail(Auth::user()->id);
         $joined = ActivityMember::isJoined($id, $user->id);
         $member = ActivityMember::where('activity_id', $id)->where('user_id', $user->id)->first();
         if ($member != null) {
             $member->load('activity');
         }
     }
     $photos = Product::findOrFail($activity->product_id)->photos;
     $members = $activity->members;
     $activities = Activity::where('istop', 1)->orderBy('order_number')->take(5)->get();
     $activities = $activities->filter(function ($item) use($activity) {
         return $item->id != $activity->id;
     });
     $models = compact('activity', 'members', 'photos', 'joined', 'activities');
     if (Auth::check()) {
         $models['user'] = $user;
         $models['member'] = $member;
     }
     return view('activity.show', $models);
 }