<?php
// src/App/DTO/RegisterUserCommand.php
final class RegisterUserCommand {
  public function __construct(
    public readonly string $email,
    public readonly string $name
  ) {}
}

// src/Domain/User/UserRules.php
final class UserRules {
  public static function validateEmail(string $email): void {
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
      throw new DomainException("E-mail inválido.");
    }
  }

  public static function validateName(string $name): void {
    $name = trim($name);
    if ($name === "" || mb_strlen($name) < 2) {
      throw new DomainException("Nome deve ter pelo menos 2 caracteres.");
    }
  }
}

// src/Domain/Contracts/UserRepository.php
interface UserRepository {
  public function existsByEmail(string $email): bool;
  public function save(User $user): void;
}

// src/Domain/User/User.php
final class User {
  public function __construct(
    public readonly string $email,
    public string $name
  ) {}

  public function rename(string $name): void {
    UserRules::validateName($name);
    $this->name = trim($name);
  }
}

// src/App/UseCases/RegisterUser.php
final class RegisterUser {
  public function __construct(
    private readonly UserRepository $users
  ) {}

  public function execute(RegisterUserCommand $cmd): void {
    UserRules::validateEmail($cmd->email);
    UserRules::validateName($cmd->name);

    if ($this->users->existsByEmail($cmd->email)) {
      throw new DomainException("Já existe um usuário com este e-mail.");
    }

    $user = new User($cmd->email, trim($cmd->name));
    $this->users->save($user);
  }
}

// src/Http/Controllers/RegisterUserController.php
final class RegisterUserController {
  public function __construct(
    private readonly RegisterUser $useCase
  ) {}

  public function handle(array $request): array {
    // Camada de entrada: validação de formato (ex.: campos presentes)
    if (!isset($request['email'], $request['name'])) {
      return ['status' => 400, 'error' => 'Campos obrigatórios: email e name.'];
    }

    try {
      $cmd = new RegisterUserCommand($request['email'], $request['name']);
      $this->useCase->execute($cmd);
      return ['status' => 201, 'message' => 'Usuário registrado com sucesso.'];
    } catch (DomainException $e) {
      return ['status' => 422, 'error' => $e->getMessage()];
    } catch (Throwable $e) {
      // Erro técnico (infra)
      return ['status' => 500, 'error' => 'Falha interna.'];
    }
  }
}