laravel 分类的列表查询

public function index(Request $request, ResponseFactoryContract $response, QuestionModel $questionModel)
{
    $userID = $request->user('api')->id ?? 0;
    $limit = max(1, min(30, $request->query('limit', 15)));
    $offset = max(0, $request->query('offset', 0));
    $subject = $request->query('subject');
    $map = [
        'all' => function ($query) {
            $query->orderBy('id', 'desc');
        },
        'new' => function ($query) {
            $query->where('answers_count', 0)
                ->orderBy('id', 'desc');
        },
        'hot' => function ($query) use ($questionModel) {
            $query->whereBetween('created_at', [
                $questionModel->freshTimestamp()->subMonth(1),
                $questionModel->freshTimestamp(),
            ])->where('answers_count', '!=', 0);
            $query->orderBy('answers_count', 'desc');
        },
        'reward' => function ($query) {
            $query->where('amount', '!=', 0)
                ->orderBy('id', 'desc');
        },
        'excellent' => function ($query) {
            $query->where('excellent', '!=', 0)
                ->orderBy('id', 'desc');
        },
        'follow' => function ($query) use ($userID) {
            $query->whereExists(function ($query) use ($userID) {
                $query->from('question_watcher')
                    ->where('question_watcher.user_id', '=', $userID)
                    ->whereRaw('question_watcher.question_id = questions.id');
            });
        },
    ];
    $type = in_array($type = $request->query('type', 'new'), array_keys($map)) ? $type : 'new';
    call_user_func($map[$type], $query = $questionModel
        ->whereDoesntHave('blacks', function ($query) use ($userID) {
            $query->where('user_id', $userID);
        })
        ->when($subject, function ($query) use ($subject) {
            return $query->where('subject', 'like', '%'.$subject.'%');
        })
        ->limit($limit)
        ->offset($offset));
    $questions = $query->get();
    $questions->load('user');

    return $response->json($questions->map(function (QuestionModel $question) use ($userID) {
        if ($question->anonymity && $question->user_id !== $userID) {
            $question->addHidden('user');
            $question->user_id = 0;
        }

        $question->answer = $question->answers()
            ->whereDoesntHave('blacks', function ($query) use ($userID) {
                $query->where('user_id', $userID);
            })
            ->with('user')
            ->orderBy('id', 'desc')
            ->first();

        if ($question->answer) {
            if ($question->answer->anonymity && $question->answer->user_id !== $userID) {
                $question->answer->addHidden('user');
                $question->answer->user_id = 0;
            }
            $question->answer->liked = (bool) $question->answer->liked($userID);
            $question->answer->collected = (bool) $question->answer->collected($userID);
            $question->answer->rewarded = (bool) $question->answer->rewarders()->where('user_id', $userID)->first();
            $question->look && $question->answer->could = true;

            if ($question->look && $question->answer->invited && (! $question->answer->onlookers()->where('user_id', $userID)->first()) && $question->answer->user_id !== $userID && $question->user_id !== $userID) {
                $question->answer->could = false;
                $question->answer->body = null;
            }
        }

        return $question;
    }))->setStatusCode(200);
}