clean_architecture.php

<?php

declare(strict_types=1);

/**
 * src/
 *   Domain/
 *     Entity/
 *     Factory/
 *     Repository/   // repository interfaces
 *     Service/
 *   Persistence/
 *     Repository/   // concrete repositories
 *   Infra/
 *     Http/
 *       Controller/
 *       Helper/
 *       ViewModel/
 */

// src/Domain/Repository
interface UserRepositoryInterface
{
    public function getAll(): UserList;
}

// src/Domain/Repository
interface AnalyticsRepositoryInterface
{
    public function getUserCount(): int;
    public function getActiveUserCount(): int;
    public function getNewUserCount(): int;
}

// src/Infra/Http/ViewModel
final class UserListViewModel
{
    private UserRepositoryInterface      $user_repository;
    private AnalyticsRepositoryInterface $analytics_repository;

    public function __construct(
        UserRepositoryInterface $user_repository,
        AnalyticsRepositoryInterface $analytics_repository
    ) {
        $this->user_repository      = $user_repository;
        $this->analytics_repository = $analytics_repository;
    }

    public function fetch(): array
    {
        return [
            'users'             => $this->user_repository->getAll(),
            'user_count'        => $this->analytics_repository->getUserCount(),
            'user_active_count' => $this->analytics_repository->getActiveUserCount(),
            'user_new_count'    => $this->analytics_repository->getNewUserCount(),
        ];
    }
}

// src/Infra/Http/Helper
final class JsonResponseHelper
{
    private array $data;

    public function __construct(array $data)
    {
        $this->data = $data;
    }

    public function parse(?ResponseInterface $response = null): ResponseInterface
    {
        $response = $response ?: new Response();

        if (!$response->getHeader('Content-Type')) {
            $response = $response->withHeader('Content-Type', 'application/json');
        }

        $response->getBody()
            ->write(json_encode($this->data, JSON_THROW_ON_ERROR));

        return $response;
    }
}

// src/Infra/Http/Controller
final class UserController
{
    private UserListViewModel $user_list_view_model;

    public function __construct(UserListViewModel $user_list_view_model)
    {
        $this->user_list_view_model = $user_list_view_model;
    }

    public function index(): ResponseInterface
    {
        return (new JsonResponseHelper($user_list_view_model->fetch()))->parse();
    }
}

Using this gist as a way to share ideas about Clean Architecture structure in PHP