Common Laravel Package

## Technical Evaluation

### **Architecture Fit**
- **DDD Alignment**: The package is purpose-built for DDD, offering standardized implementations for **entities, value objects, aggregates, repositories, and domain events**. This aligns perfectly with Laravel projects aiming for **clean architecture** or **microservices** where bounded contexts are critical. The package’s abstractions (e.g., `AggregateRoot`, `RepositoryInterface`) enforce DDD principles without locking teams into a monolithic framework.
- **Layered Architecture**: Complements Laravel’s **MVC/Service Layer** pattern by:
  - Isolating domain logic in **entities/value objects** (Domain Layer).
  - Delegating persistence to **custom repositories** (Infrastructure Layer), which can wrap Eloquent or other ORMs.
- **Ubiquitous Language**: Encourages alignment between technical and business teams by providing **type-safe domain primitives** (e.g., `Money`, `Email`) that mirror real-world concepts.

### **Integration Feasibility**
- **Laravel Synergy**:
  - **Service Container**: The package’s interfaces (e.g., `RepositoryInterface`) can be bound to Laravel’s container, enabling dependency injection for domain objects.
  - **Events**: Domain events can integrate with Laravel’s **event system** or **queue workers** for async processing.
  - **Testing**: Works seamlessly with Laravel’s **PestPHP/PHPUnit** for unit/integration tests (e.g., testing domain invariants).
- **Incremental Adoption**:
  - Start with **entities/value objects** (low risk, high reward).
  - Gradually introduce **repositories** and **domain events** as confidence grows.
- **ORM Flexibility**:
  - Repositories can abstract **Eloquent, Query Builder, or even external APIs**, making the package adaptable to non-DB use cases (e.g., GraphQL APIs).

### **Technical Risk**
- **Immaturity**: With **0 stars/dependents**, risks include:
  - **Undocumented edge cases** (e.g., event dispatching, repository transactions).
  - **Lack of Laravel-specific optimizations** (e.g., Eloquent integration quirks).
- **Performance Overhead**:
  - Reflection-based DDD patterns (e.g., dynamic event publishing) may introduce latency. **Benchmark critical paths** (e.g., aggregate loading).
- **Design Assumptions**:
  - Potential conflicts with Laravel’s **conventions** (e.g., UUIDs vs. auto-increment IDs, event naming).
  - Unclear support for **CQRS** or **event sourcing** (may require additional packages).
- **Testing Gaps**:
  - Limited test coverage in the package could expose **domain logic bugs** (e.g., invariant violations).

### **Key Questions**
1. **DDD Maturity**: Is the team’s DDD adoption **strategic** (e.g., greenfield project) or **tactical** (e.g., refactoring legacy code)? This impacts integration scope.
2. **Persistence Strategy**:
   - Will repositories use **Eloquent**, **raw queries**, or a **custom ORM**? Clarify mapping strategies (e.g., single-table inheritance for aggregates).
3. **Event Handling**:
   - Does the package support **Laravel’s event system** natively, or will a **custom dispatcher** be needed?
   - How are **domain events** serialized/deserialized (e.g., JSON, custom format)?
4. **Alternatives**:
   - Compare with **Spatie’s Laravel DDD**, **Fruitcake’s DDD**, or **Symfony’s DDD bundles** for maturity and Laravel-specific features.
5. **Long-Term Viability**:
   - What’s the **maintenance roadmap** for the package? Will it evolve alongside Laravel?
6. **Tooling**:
   - Does the package integrate with **Laravel Forge/Sail** for deployment or **Laravel Horizon** for event processing?

---

## Integration Approach

### **Stack Fit**
- **Laravel Ecosystem**:
  - **Composer**: Seamless installation via `composer require dddominio/common`.
  - **Service Container**: Bind package interfaces to Laravel’s container for DI (e.g., repositories, event dispatchers).
  - **Events**: Leverage Laravel’s **event system** or **queue workers** for async domain events.
  - **Testing**: Compatible with **PestPHP**, **PHPUnit**, and **Mockery** for testing domain logic.
- **Architecture Patterns**:
  - **Clean Architecture**: Place domain layer in `app/Domain`; infrastructure (repositories) in `app/Infrastructure`.
  - **Hexagonal Architecture**: Use the package’s ports (e.g., `RepositoryInterface`) to decouple domain from Laravel’s Eloquent.
- **Tooling**:
  - **IDE Support**: PHPStorm’s DDD plugins can enhance navigation for entities/aggregates.
  - **CI/CD**: Add tests for domain invariants to pre-commit hooks.

### **Migration Path**
1. **Phase 1: Domain Primitives (1–2 weeks)**
   - Replace **plain PHP classes** with `DDDominio\Common\Entity` and `DDDominio\Common\ValueObject`.
   - Example:
     ```php
     // Before
     class User {
         public function __construct(public string $id, public string $name) {}
     }

     // After
     use DDDominio\Common\Entity;
     class User extends Entity {
         public function __construct(
             public string $id,
             public string $name
         ) {}
     }
     ```
   - **Validation**: Write unit tests for immutability, identity, and equality.

2. **Phase 2: Repositories (2–3 weeks)**
   - Implement `DDDominio\Common\Repository\RepositoryInterface` for aggregates.
   - Example:
     ```php
     class UserRepository implements RepositoryInterface {
         public function find(string $id): ?User {
             return UserModel::find($id)->toDomain(); // Custom mapper
         }
     }
     ```
   - **Binding**: Register repositories in Laravel’s container:
     ```php
     $this->app->bind(UserRepository::class, function ($app) {
         return new EloquentUserRepository(new UserModel());
     });
     ```
   - **Persistence**: Decide on **ORM strategy** (e.g., Eloquent, raw queries) and create mappers.

3. **Phase 3: Domain Events (1–2 weeks)**
   - Map `DDDominio\Common\Domain\Event` to Laravel events or a custom dispatcher.
   - Example:
     ```php
     use DDDominio\Common\Domain\Event\DomainEvent;

     class OrderCreated implements DomainEvent {
         public function __construct(public string $orderId) {}
     }

     // Dispatch in entity:
     $this->domainEventDispatcher->dispatch(new OrderCreated($orderId));
     ```
   - **Integration**: Use Laravel’s **event listeners** or **queue workers** for async processing.

4. **Phase 4: Domain Services (Ongoing)**
   - Encapsulate **business logic** in services (e.g., `OrderService`) using injected repositories/entities.
   - Example:
     ```php
     class OrderService {
         public function __construct(
             private UserRepository $userRepository,
             private OrderRepository $orderRepository
         ) {}

         public function createOrder(string $userId, array $items) {
             $user = $this->userRepository->find($userId);
             // Business logic...
         }
     }
     ```

### **Compatibility**
- **Laravel Versions**: Test with **Laravel 10.x** (PHP 8.1+). Check for breaking changes in newer Laravel releases.
- **Package Dependencies**:
  - Audit for conflicts with **Eloquent**, **Livewire**, or other ORM/event packages.
  - Example conflict: If the package uses `symfony/event-dispatcher`, ensure Laravel’s event system doesn’t clash.
- **Customization**:
  - Override package defaults (e.g., **UUID generation**, **event naming**) via config or service providers.
  - Example: Publish the package’s config:
    ```bash
    php artisan vendor:publish --provider="DDDominio\Common\CommonServiceProvider"
    ```

### **Sequencing**
- **Pilot Module**: Start with a **low-risk domain** (e.g., `User`, `Product`) to validate integration.
- **Incremental Rollout**:
  1. **Entities/Value Objects**: Replace 1–2 domain models.
  2. **Repositories**: Implement for critical aggregates (e.g., `Order`).
  3. **Events**: Add domain events for **audit logs** or **notifications**.
- **Parallel Development**:
  - Maintain **dual implementations** (e.g., Eloquent + DDDominio) during migration.
  - Use **feature flags** to toggle between old/new domain logic.

---

## Operational Impact

### **Maintenance**
- **Dependency Management**:
  - Monitor the package for **breaking changes** (e.g., interface modifications).
  - Pin versions in `composer.json` to avoid surprises:
    ```json
    "require": {
        "dddominio/common": "^1.0"
    }
    ```
- **Custom Code**:
  - Isolate package-specific logic (e.g., repository implementations) in **separate classes** for easier updates.
  - Example: Use **adapters** to abstract away package changes:
    ```php
    class EloquentUserRepositoryAdapter implements UserRepository {
        public function __construct