深入理解MVC分层架构：控制器与仓储层交互的最佳实践

// app/Repositories/UserRepository.php
namespace App\Repositories;

use App\Models\User;

interface UserRepository
{
    public function findById(int $id): ?User;
    public function save(User $user): User;
    public function delete(User $user): void;
    // ... 其他数据访问方法
}

// app/Repositories/EloquentUserRepository.php (基于Laravel Eloquent的实现)
namespace App\Repositories;

use App\Models\User;
use App\Repositories\UserRepository;

class EloquentUserRepository implements UserRepository
{
    public function findById(int $id): ?User
    {
        return User::find($id);
    }

    public function save(User $user): User
    {
        $user->save();
        return $user;
    }

    public function delete(User $user): void
    {
        $user->delete();
    }
}

// app/Services/UserService.php
namespace App\Services;

use App\Models\User;
use App\Repositories\UserRepository;
use Illuminate\Support\Facades\Hash;
use Illuminate\Validation\ValidationException; // 假设业务验证

class UserService
{
    private UserRepository $userRepository;

    public function __construct(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;
    }

    /**
     * 创建一个新用户。
     *
     * @param array $userData 包含用户数据的关联数组
     * @return User
     * @throws ValidationException
     */
    public function createUser(array $userData): User
    {
        // 业务逻辑验证，例如检查邮箱是否已存在
        if ($this->userRepository->findByEmail($userData['email'])) {
            throw ValidationException::withMessages([
                'email' => ['该邮箱已被注册。']
            ]);
        }

        $user = new User();
        $user->name = $userData['name'];
        $user->email = $userData['email'];
        $user->password = Hash::make($userData['password']); // 密码哈希处理

        return $this->userRepository->save($user);
    }

    /**
     * 更新现有用户信息。
     *
     * @param int $id 用户ID
     * @param array $updates 要更新的数据
     * @return User
     * @throws \Exception
     */
    public function updateUser(int $id, array $updates): User
    {
        $user = $this->userRepository->findById($id);

        if (!$user) {
            throw new \Exception('用户未找到。');
        }

        if (isset($updates['name'])) {
            $user->name = $updates['name'];
        }
        if (isset($updates['email'])) {
            // 业务逻辑验证：更新邮箱时，检查新邮箱是否已被其他用户使用
            $existingUser = $this->userRepository->findByEmail($updates['email']);
            if ($existingUser && $existingUser->id !== $user->id) {
                throw ValidationException::withMessages([
                    'email' => ['该邮箱已被其他用户注册。']
                ]);
            }
            $user->email = $updates['email'];
        }
        // ... 其他更新逻辑

        return $this->userRepository->save($user);
    }

    public function getUserById(int $id): ?User
    {
        return $this->userRepository->findById($id);
    }

    // ... 其他业务方法
}

// app/Http/Controllers/UserController.php
namespace App\Http\Controllers;

use App\Services\UserService;
use Illuminate\Http\Request;
use Illuminate\Validation\ValidationException;

class UserController extends Controller
{
    private UserService $userService;

    public function __construct(UserService $userService)
    {
        $this->userService = $userService;
    }

    /**
     * 显示所有用户列表。
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        // 这里的逻辑可能更复杂，例如分页、过滤等，也应由服务层提供
        // 为简化，这里假设直接从服务获取所有用户，实际应有 getAllUsers() 方法
        $users = $this->userService->getAllUsers(); // 假设服务层提供了这个方法
        return view('users.index', compact('users'));
    }

    /**
     * 处理创建新用户的请求。
     *
     * @param Request $request
     * @return \Illuminate\Http\RedirectResponse
     */
    public function store(Request $request)
    {
        try {
            // 1. 验证用户输入 (控制器职责)
            $validatedData = $request->validate([
                'name' => 'required|string|max:255',
                'email' => 'required|string|email|max:255|unique:users',
                'password' => 'required|string|min:8|confirmed',
            ]);

            // 2. 调用服务层处理业务逻辑 (控制器职责：协调)
            $user = $this->userService->createUser($validatedData);

            // 3. 返回响应 (控制器职责)
            return redirect()->route('users.show', $user->id)
                             ->with('success', '用户创建成功！');

        } catch (ValidationException $e) {
            return back()->withErrors($e->errors())->withInput();
        } catch (\Exception $e) {
            return back()->with('error', '创建用户失败：' . $e->getMessage())->withInput();
        }
    }

    /**
     * 显示指定用户。
     *
     * @param int $id
     * @return \Illuminate\Http\Response
     */
    public function show(int $id)
    {
        $user = $this->userService->getUserById($id);

        if (!$user) {
            abort(404, '用户未找到');
        }

        return view('users.show', compact('user'));
    }

    // ... 其他更新、删除等方法
}