# Service Template / Template Dịch Vụ

> **EN**: Standard template for creating new microservices in the @goodgo ecosystem.
> **VI**: Template chuẩn để tạo các microservice mới trong hệ sinh thái @goodgo.

## Features / Tính Năng

- **Framework**: Express.js with TypeScript / Express.js với TypeScript.
- **Database**: Prisma ORM with PostgreSQL / Prisma ORM với PostgreSQL.
- **Validation**: Zod for environment & input validation / Zod cho validation biến môi trường và đầu vào.
- **Observability / Khả năng quan sát**:
    - **Metrics**: Prometheus metrics at `/metrics` / Metrics Prometheus tại `/metrics`.
    - **Logging**: Common logger with request tracking / Logger chung với theo dõi request.
    - **Tracing**: OpenTelemetry/Jaeger integration / Tích hợp OpenTelemetry/Jaeger.
- **Resilience / Khả năng phục hồi**:
    - Graceful shutdown / Đóng ứng dụng an toàn.
    - Rate limiting (Distributed via Redis) / Giới hạn tốc độ request (Phân tán qua Redis).
    - Circuit Breaker / Ngắt mạch.
    - Health checks (liveness/readiness) / Kiểm tra sức khỏe hệ thống.
- **Caching**: Redis caching strategy / Chiến lược caching với Redis.
- **Security / Bảo mật**: Helmet & CORS configured / Đã cấu hình Helmet & CORS.

## Project Structure / Cấu trúc Dự án

```
src/
├── config/         # Configuration & Env validation / Cấu hình & Validate biến môi trường
├── middlewares/    # Express middlewares (error, logger, metrics)
├── modules/        # Feature modules (controller, service, repository)
├── routes/         # API route definitions
└── main.ts         # Entry point & App bootstrapping
```

## Getting Started / Bắt đầu

### Prerequisites / Yêu cầu tiên quyết

- Node.js >= 20
- pnpm
- Docker (Redis required)

### Installation / Cài đặt

#### Option 1: Local Development / Phát triển Cục bộ

1.  **Clone & Install dependencies**:
    ```bash
    pnpm install
    ```

2.  **Start infrastructure with Docker**:
    
    For local development, start the platform infrastructure from `deployments/local/`:
    Để phát triển local, khởi động hạ tầng nền tảng từ `deployments/local/`:
    
    ```bash
    # Navigate to deployments directory
    cd deployments/local
    
    # Start platform services (PostgreSQL, Redis, Traefik, etc.)
    docker-compose up -d redis
    
    # Return to service directory
    cd ../../services/_template
    ```
    
    **Note**: For full platform deployment with all services, see "Adding This Service to the Platform" section below.
    **Lưu ý**: Để triển khai nền tảng đầy đủ với tất cả services, xem phần "Thêm Service Vào Nền Tảng" bên dưới.

3.  **Setup database**:
    ```bash
    pnpm prisma migrate dev
    pnpm prisma db seed
    ```

4.  **Start development server**:
    ```bash
    pnpm dev
    ```

2.  **Environment Setup / Thiết lập môi trường**:

    Environment variables are managed at the **platform level**, not per-service:
    Biến môi trường được quản lý ở **cấp độ nền tảng**, không phải mỗi service:

    ```bash
    # EN: Setup shared environment variables (from deployments/local/)
    # VI: Thiết lập biến môi trường chung (từ deployments/local/)
    cd deployments/local
    cp env.local.example .env.local
    # Edit .env.local with your values (JWT_SECRET, DATABASE_URL, etc.)
    ```

    **Environment Variables / Biến Môi trường**:
    
    **Shared Variables** (in `deployments/local/.env.local`):
    - `JWT_SECRET`, `JWT_REFRESH_SECRET` - Must be same across all services
    - `REDIS_HOST`, `REDIS_PORT` - Shared Redis instance
    - `CORS_ORIGIN` - Allowed origins for all services
    - `NODE_ENV`, `LOG_LEVEL` - Common configuration

    **Service-Specific Variables** (in `docker-compose.yml`):
    - `PORT` - Unique port for each service
    - `DATABASE_URL` - Service's database connection
    - `SERVICE_NAME` - Service identifier

    **Key Environment Variables / Biến Môi Trường Chính**:

    | Variable / Biến | Description / Mô tả | Default / Mặc định | Required / Bắt buộc |
    |-----------------|---------------------|-------------------|---------------------|
    | `PORT` | Server port / Cổng server | `5000` | No / Không |
    | `NODE_ENV` | Environment mode / Chế độ môi trường | `development` | No / Không |
    | `API_VERSION` | API version prefix / Tiền tố phiên bản API | `v1` | No / Không |
    | `CORS_ORIGIN` | Allowed CORS origins (comma-separated) / Origins CORS được phép | `http://localhost:3000` | No / Không |
    | `SERVICE_NAME` | Service identifier / Mã định danh service | `microservice-template` | No / Không |
    | `DATABASE_URL` | PostgreSQL connection string / Chuỗi kết nối PostgreSQL | - | **Yes / Có** |
    | `REDIS_URL` | Redis connection URL / URL kết nối Redis | `redis://localhost:6379` | No / Không |
    | `JWT_SECRET` | JWT secret key for token signing and verification / Khóa bí mật JWT để ký và xác minh token | - | **Yes / Có** |
    | `TRACING_ENABLED` | Enable Jaeger tracing / Bật tracing Jaeger | `false` | No / Không |
    | `JAEGER_ENDPOINT` | Jaeger collector endpoint / Endpoint collector Jaeger | - | No / Không |

    **Environment Configuration Priority / Ưu tiên Cấu hình Môi trường**:
    1. **Docker Compose environment** (in `deployments/local/docker-compose.yml`) - Highest priority
    2. **Shared `.env.local`** (in `deployments/local/.env.local`) - Platform-level shared configs
    3. **System environment variables** - OS-level environment

3.  **Database Setup / Thiết lập Database**:

    **Prerequisites / Yêu cầu tiên quyết**:
    - PostgreSQL database running / Database PostgreSQL đang chạy
    - `DATABASE_URL` configured in `.env` / `DATABASE_URL` đã được cấu hình trong `.env`

    **Database Workflow / Quy trình Database**:
    ```bash
    # EN: Generate Prisma client / Tạo Prisma client
    pnpm prisma:generate

    # EN: Create and run initial migration / Tạo và chạy migration ban đầu
    pnpm prisma:migrate

    # EN: (Optional) Seed database with initial data / (Tùy chọn) Seed database với dữ liệu ban đầu
    pnpm prisma:seed
    ```

    **Development Workflow / Quy trình Phát triển**:
    ```bash
    # EN: After schema changes, regenerate client / Sau khi thay đổi schema, tạo lại client
    pnpm prisma:generate

    # EN: Create new migration for schema changes / Tạo migration mới cho thay đổi schema
    pnpm prisma:migrate dev --name your-migration-name

    # EN: View database in Prisma Studio / Xem database trong Prisma Studio
    pnpm prisma:studio
    ```

    **Production Deployment / Triển khai Production**:
    ```bash
    # EN: Deploy migrations to production / Triển khai migrations lên production
    pnpm prisma:migrate deploy

    # EN: Reset database (CAUTION: destroys all data) / Reset database (CẨN THẬN: xóa tất cả dữ liệu)
    pnpm prisma:migrate reset
    ```

4.  **Run Development / Chạy môi trường phát triển**:
    ```bash
    pnpm dev
    ```

5.  **Build & Start Production / Build và Chạy Production**:
    ```bash
    pnpm build
    pnpm start
    ```

## Adding This Service to the Platform / Thêm Service Vào Nền Tảng

This template represents a **single microservice**. To deploy it as part of the GoodGo microservices platform:
Template này đại diện cho **một microservice đơn lẻ**. Để triển khai nó như một phần của nền tảng microservices GoodGo:

### 1. Register in Platform Compose File / Đăng Ký Trong Platform Compose File

Add your service to `deployments/local/docker-compose.yml`:
Thêm service của bạn vào `deployments/local/docker-compose.yml`:

```yaml
services:
  your-service:
    build:
      context: ../..
      dockerfile: services/your-service/Dockerfile
    container_name: your-service-local
    environment:
      - NODE_ENV=development
      - PORT=5002
      - DATABASE_URL=${DATABASE_URL}
      - REDIS_HOST=redis
      - REDIS_PORT=6379
      - JWT_SECRET=${JWT_SECRET}
      - SERVICE_NAME=your-service
      - API_VERSION=v1
      - CORS_ORIGIN=http://localhost:3000,http://localhost:3001
    depends_on:
      redis:
        condition: service_healthy
    networks:
      - microservices-network
    labels:
      # Enable Traefik service discovery
      - "traefik.enable=true"
      # Define routing rule (path-based routing)
      - "traefik.http.routers.your-service.rule=PathPrefix(`/api/v1/your-service`)"
      # Specify the service port
      - "traefik.http.services.your-service.loadbalancer.server.port=5002"
      # Health check configuration
      - "traefik.http.services.your-service.loadbalancer.healthcheck.path=/health/live"
      - "traefik.http.services.your-service.loadbalancer.healthcheck.interval=10s"
```

### 2. Start the Platform / Khởi Động Nền Tảng

```bash
# Navigate to deployments directory
cd deployments/local

# Start all services including your new service
docker-compose up -d

# View logs for your service
docker-compose logs -f your-service
```

### 3. Access Your Service / Truy Cập Service Của Bạn

Once deployed, your service is accessible through Traefik:
Sau khi triển khai, service của bạn có thể truy cập qua Traefik:

- **API**: http://localhost/api/v1/your-service
- **Health Check**: http://localhost/api/v1/your-service/health
- **API Documentation**: http://localhost/api/v1/your-service/api-docs
- **Traefik Dashboard**: http://localhost:8080 (view all registered services)

### 4. Traefik Configuration / Cấu Hình Traefik

Traefik is configured at the platform level in `infra/traefik/`:
Traefik được cấu hình ở cấp độ nền tảng trong `infra/traefik/`:

- **Static Config**: `infra/traefik/traefik.yml` - Entry points, providers, dashboard
- **Dynamic Config**: `infra/traefik/dynamic/` - Middlewares, routes, services
- **Service Discovery**: Automatic via Docker labels (no manual route configuration needed)

For advanced routing or middleware, add to `infra/traefik/dynamic/routes.yml`:
Để định tuyến nâng cao hoặc middleware, thêm vào `infra/traefik/dynamic/routes.yml`:

```yaml
http:
  routers:
    your-service:
      rule: "PathPrefix(`/api/v1/your-service`)"
      service: your-service
      middlewares:
        - secure-headers
        - cors
        - compress
```

## Observability / Khả năng quan sát

When deployed via the platform (`deployments/local/docker-compose.yml`), your service exposes:
Khi triển khai qua nền tảng (`deployments/local/docker-compose.yml`), service của bạn expose:

- **Metrics**: `http://localhost/api/v1/your-service/metrics` (Prometheus format via Traefik)
- **Health Checks**:
    - Liveness: `http://localhost/api/v1/your-service/health/live`
    - Readiness: `http://localhost/api/v1/your-service/health/ready`
- **API Documentation**: `http://localhost/api/v1/your-service/api-docs` (Swagger UI via Traefik)
- **Tracing**: Jaeger integration (when `TRACING_ENABLED=true`)
- **Correlation IDs**: Automatic request tracing with `x-correlation-id` headers
- **Structured Logging**: Request/response logging with correlation context

**Note**: For local development (without platform), replace `/api/v1/your-service` with `http://localhost:5000`.
**Lưu ý**: Để phát triển local (không dùng platform), thay `/api/v1/your-service` bằng `http://localhost:5000`.

### Metrics / Metrics

The service exposes comprehensive Prometheus metrics:

- **Request Duration**: `http_request_duration_seconds` (histogram)
- **Request Count**: `http_requests_total` (counter)
- **Active Requests**: `http_active_requests` (gauge)
- **Request Errors**: `http_request_errors_total` (counter)
- **Payload Sizes**: Request/response payload size histograms
- **Default Metrics**: Memory, CPU, event loop lag

### Correlation IDs / Correlation IDs

Every request gets a correlation ID for tracing across services:

- **Header**: `x-correlation-id` (propagated from upstream or auto-generated)
- **Request ID**: `x-request-id` (unique per request)
- **Logging**: All logs include correlation context
- **Metrics**: Request metrics tagged with correlation ID

### Health Checks / Health Checks

- **Liveness** (`/health/live`): Basic service availability
- **Readiness** (`/health/ready`): Service ready to handle requests (includes DB connectivity)
- **Metrics**: Health check results are tracked in Prometheus metrics

### Logging / Logging

Structured logging with multiple levels:

- **Request/Response**: Automatic logging with correlation IDs
- **Errors**: Detailed error logging with stack traces
- **Business Logic**: Custom logging with context
- **Performance**: Request duration and resource usage

### API Documentation / Tài liệu API

- **Swagger UI**: Interactive API documentation at `/api-docs`
- **OpenAPI 3.0**: Complete API specification
- **Request/Response Examples**: Real examples for all endpoints
- **Authentication**: JWT Bearer token examples

## Authentication / Xác thực

The service uses JWT (JSON Web Tokens) for authentication. Include the token in the `Authorization` header as `Bearer <token>`.

### API Documentation / Tài liệu API

#### Authentication Endpoints / Endpoints Xác thực

**Get Current User Info / Lấy Thông tin Người dùng Hiện tại**
```http
GET /auth/me
Authorization: Bearer <your-jwt-token>
```

#### Feature Management / Quản lý Feature

**Base URL**: `http://localhost/api/v1/features`

#### Create Feature / Tạo Feature
```http
POST /api/v1/features
Authorization: Bearer <admin-jwt-token>
Content-Type: application/json

{
  "name": "example-feature",
  "title": "Example Feature",
  "description": "An example feature for demonstration",
  "config": {
    "enabled": true,
    "priority": 1
  },
  "tags": ["example", "demo"]
}
```
**Required Role:** `admin`

#### Get All Features / Lấy Tất cả Features
```http
GET /api/v1/features
```

#### Get Feature by ID / Lấy Feature theo ID
```http
GET /api/v1/features/{id}
```

#### Update Feature / Cập nhật Feature
```http
PUT /api/v1/features/{id}
Content-Type: application/json

{
  "title": "Updated Title",
  "enabled": false
}
```

#### Delete Feature / Xóa Feature
```http
DELETE /api/v1/features/{id}
```

#### Toggle Feature Status / Chuyển đổi Trạng thái Feature
```http
PATCH /api/v1/features/{id}/toggle
```

### Response Format / Định dạng Response

All API responses follow this structure / Tất cả responses API tuân theo cấu trúc này:

```json
{
  "success": true,
  "data": { ... },
  "message": "Operation completed / Hoạt động hoàn thành",
  "timestamp": "2024-01-01T00:00:00.000Z"
}
```

Error responses / Responses lỗi:
```json
{
  "success": false,
  "error": {
    "code": "FEATURE_001",
    "message": "Error description / Mô tả lỗi"
  },
  "timestamp": "2024-01-01T00:00:00.000Z"
}
```

## Troubleshooting / Khắc phục sự cố

### Common Issues / Vấn đề thường gặp

#### Database Connection Issues / Vấn đề kết nối Database

**Problem**: `Error: P1001: Can't reach database server`
```bash
# EN: Check if PostgreSQL is running (from deployments/local/)
# VI: Kiểm tra PostgreSQL có đang chạy (từ deployments/local/)
cd deployments/local
docker-compose ps

# EN: Check database logs
# VI: Kiểm tra logs database
docker-compose logs postgres

# EN: Restart database service
# VI: Khởi động lại database service
docker-compose restart postgres
```

**Problem**: `Error: P2002: Unique constraint failed`
```typescript
// EN: This usually means you're trying to create a duplicate record
// VI: Điều này thường có nghĩa là bạn đang cố tạo record trùng lặp
// EN: Check your seed data or migration scripts
// VI: Kiểm tra seed data hoặc migration scripts
```

#### Authentication Issues / Vấn đề Authentication

**Problem**: `401 Unauthorized`
```bash
# EN: Check JWT token format
# VI: Kiểm tra định dạng JWT token
curl -H "Authorization: Bearer YOUR_TOKEN" http://localhost/auth/me

# EN: Verify JWT secret in environment
# VI: Xác minh JWT secret trong environment
echo $JWT_SECRET

# EN: Check token expiration
# VI: Kiểm tra token hết hạn
# EN: Use https://jwt.io to decode your token
```

#### Port Already in Use / Port đã được sử dụng

**Problem**: `Error: listen EADDRINUSE: address already in use`
```bash
# EN: Find process using the port
# VI: Tìm process đang sử dụng port
lsof -i :5000

# EN: Kill the process
# VI: Kill process
kill -9 <PID>

# EN: Or change port in .env
# VI: Hoặc thay đổi port trong .env
PORT=5001
```

#### Docker Issues / Vấn đề Docker

**Problem**: `ERROR: Couldn't connect to Docker daemon`
```bash
# EN: Start Docker service
# VI: Khởi động Docker service
sudo systemctl start docker

# EN: Add user to docker group (Linux)
# VI: Thêm user vào docker group (Linux)
sudo usermod -aG docker $USER
```

**Problem**: Container won't start
```bash
# EN: Check container logs (from deployments/local/)
# VI: Kiểm tra logs container (từ deployments/local/)
cd deployments/local
docker-compose logs your-service

# EN: Check container health
# VI: Kiểm tra health container
docker-compose ps

# EN: Rebuild without cache
# VI: Rebuild không dùng cache
docker-compose build --no-cache your-service
docker-compose up -d your-service
```

#### Test Failures / Test thất bại

**Problem**: Tests fail with database connection
```bash
# EN: Ensure test database is running
# VI: Đảm bảo test database đang chạy
docker-compose -f docker-compose.test.yml up -d

# EN: Run tests with verbose output
# VI: Chạy tests với output verbose
pnpm test -- --verbose

# EN: Reset test database
# VI: Reset test database
docker-compose -f docker-compose.test.yml down -v
```

### Debug Mode / Chế độ Debug

```bash
# EN: Enable debug logging (local development)
# VI: Bật debug logging (phát triển local)
DEBUG=* pnpm dev

# EN: Check application health (via platform)
# VI: Kiểm tra health ứng dụng (qua platform)
curl http://localhost/api/v1/your-service/health/ready

# EN: View application logs (from deployments/local/)
# VI: Xem logs ứng dụng (từ deployments/local/)
cd deployments/local
docker-compose logs -f your-service

# EN: Monitor metrics (via platform)
# VI: Monitor metrics (qua platform)
curl http://localhost/api/v1/your-service/metrics
```

### Performance Issues / Vấn đề Performance

**Slow Requests**:
- Check database query performance
- Review middleware chain efficiency
- Monitor Redis cache hit rates
- Check for memory leaks

**High Memory Usage**:
```bash
# EN: Check memory usage
# VI: Kiểm tra memory usage
docker stats

# EN: Monitor with Prometheus metrics
# VI: Monitor với Prometheus metrics
curl http://localhost/metrics | grep heap
```

## Docker / Docker

### Docker Image / Docker Image

This template includes a production-ready Dockerfile with:
Template này bao gồm Dockerfile production-ready với:

```dockerfile
# Multi-stage build for optimized image size
FROM node:20-alpine AS base
# ... dependency installation
FROM base AS builder
# ... build stage
FROM node:20-alpine AS runner
# ... production runtime
```

**Build the image:**
```bash
docker build -t your-service:latest .
```

### Docker Compose for Testing / Docker Compose Cho Testing

- **`docker-compose.test.yml`**: Isolated test environment with test database and Redis

**Run tests in Docker:**
```bash
docker-compose -f docker-compose.test.yml up -d
DATABASE_URL=postgresql://postgres:test_password@localhost:5433/microservice_test pnpm test
docker-compose -f docker-compose.test.yml down -v
```

### Production Deployment / Triển khai Production

For production deployment, services are orchestrated via:
Để triển khai production, các service được điều phối qua:

- **Local/Dev**: `deployments/local/docker-compose.yml`
- **Staging**: `deployments/staging/kubernetes/` (Kubernetes manifests)
- **Production**: `deployments/production/kubernetes/` (Kubernetes manifests)

**Build production image:**
```bash
docker build -t your-service:v1.0.0 .
docker tag your-service:v1.0.0 registry.example.com/your-service:v1.0.0
docker push registry.example.com/your-service:v1.0.0
```

### Docker Image Features / Tính năng Docker Image

- **Multi-stage Build**: Optimized for small production images
- **Security**: Non-root user, minimal attack surface
- **Health Checks**: Built-in health check endpoints
- **Signal Handling**: Proper signal handling with dumb-init
- **Layer Caching**: Efficient Docker layer caching

### Environment Variables for Docker / Biến môi trường cho Docker

When running in Docker, ensure these environment variables are set:

```bash
# EN: Database connection
# VI: Kết nối database
DATABASE_URL=postgresql://postgres:password@postgres:5432/microservice_template

# EN: Redis connection
# VI: Kết nối Redis
REDIS_URL=redis://redis:6379

# EN: JWT secret (change in production!)
# VI: JWT secret (thay đổi trong production!)
JWT_SECRET=your-production-jwt-secret
```

## Testing / Kiểm thử

```bash
# EN: Run all tests / Chạy tất cả tests
pnpm test

# EN: Run unit tests only / Chạy chỉ unit tests
pnpm test:unit

# EN: Run E2E tests only / Chạy chỉ E2E tests
pnpm test:e2e

# EN: Run tests with coverage / Chạy tests với coverage
pnpm test:coverage

# EN: Run tests in watch mode / Chạy tests ở chế độ watch
pnpm test:watch

# EN: Run tests in specific file / Chạy tests trong file cụ thể
pnpm test src/modules/feature/__tests__/feature.service.test.ts

# EN: Run tests matching pattern / Chạy tests khớp pattern
pnpm test -- --testNamePattern="authentication"
```

### Test Structure / Cấu trúc Test

```
src/
├── middlewares/__tests__/          # Middleware unit tests
├── modules/
│   ├── feature/__tests__/          # Feature module tests
│   └── health/__tests__/           # Health module tests
├── __tests__/                      # E2E tests
│   ├── health.e2e.ts              # Health endpoint E2E
│   └── feature.e2e.ts             # Feature endpoint E2E
└── config/__tests__/               # Configuration tests
```

### Writing Tests / Viết Tests

#### Unit Test Example / Ví dụ Unit Test

```typescript
import { FeatureService } from '../feature.service';
import { featureRepository } from '../feature.repository';

jest.mock('../feature.repository');

describe('FeatureService', () => {
  let service: FeatureService;

  beforeEach(() => {
    service = new FeatureService();
  });

  it('should create feature successfully', async () => {
    const mockFeature = { id: '1', name: 'test', enabled: true };
    (featureRepository.create as jest.Mock).mockResolvedValue(mockFeature);

    const result = await service.create({ name: 'test' });
    expect(result).toEqual(mockFeature);
  });
});
```

#### E2E Test Example / Ví dụ E2E Test

```typescript
import request from 'supertest';
import express from 'express';
import { createRouter } from '../routes';

describe('Feature Endpoints E2E', () => {
  let app: express.Application;

  beforeAll(() => {
    app = express();
    app.use(express.json());
    app.use(createRouter());
  });

  it('should create feature successfully', async () => {
    const response = await request(app)
      .post('/api/v1/features')
      .send({ name: 'test-feature' })
      .expect(201);

    expect(response.body.success).toBe(true);
  });
});
```

## Creating a New Service / Tạo Service Mới

To create a new microservice from this template / Để tạo microservice mới từ template này:

1.  **Copy Template / Sao chép Template**:
    ```bash
    # EN: Copy template to new service directory / Sao chép template vào thư mục service mới
    cp -r services/_template services/your-service-name
    cd services/your-service-name
    ```

2.  **Update Package Configuration / Cập nhật Cấu hình Package**:
    ```bash
    # EN: Update package.json name and description / Cập nhật tên và mô tả trong package.json
    # VI: Thay đổi "name", "description", và các thông tin khác
    ```

3.  **Configure Environment / Cấu hình Môi trường**:
    ```bash
    # EN: Set up shared environment variables at platform level
    # VI: Thiết lập biến môi trường chung ở cấp độ nền tảng
    cd ../../deployments/local
    cp env.local.example .env.local
    
    # EN: Edit .env.local with shared values (JWT_SECRET, DATABASE_URL, etc.)
    # VI: Chỉnh sửa .env.local với các giá trị chung (JWT_SECRET, DATABASE_URL, etc.)
    nano .env.local
    ```

4.  **Database Setup / Thiết lập Database**:
    ```bash
    # EN: Update Prisma schema with your models / Cập nhật schema Prisma với models của bạn
    # VI: Chỉnh sửa prisma/schema.prisma

    # EN: Generate and run migrations / Tạo và chạy migrations
    pnpm prisma:generate
    pnpm prisma:migrate
    ```

5.  **Implement Business Logic / Triển khai Logic Kinh doanh**:
    - Add your modules in `src/modules/`
    - Update routes in `src/routes/index.ts`
    - Add validation schemas and DTOs

6.  **Testing / Kiểm thử**:
    ```bash
    # EN: Add tests for your new functionality / Thêm tests cho chức năng mới
    pnpm test
    ```

7.  **Documentation / Tài liệu**:
    - Update `README.md` with service-specific information
    - Update `ARCHITECTURE.md` if needed
    - Update OpenAPI documentation in route files

## Extending the Template / Mở rộng Template

### Adding a New Module / Thêm Module Mới

1. **Create Module Structure / Tạo cấu trúc Module**:
   ```bash
   mkdir -p src/modules/your-module/{__tests__}
   touch src/modules/your-module/your-module.{controller,service,repository,dto,module}.ts
   touch src/modules/your-module/__tests__/your-module.{service,controller}.test.ts
   ```

2. **Implement Repository / Triển khai Repository**:
   ```typescript
   // src/modules/your-module/your-module.repository.ts
   import { BaseRepository } from '../common/repository';
   import { prisma } from '../../config/database.config';

   export class YourModuleRepository extends BaseRepository<YourEntity, CreateInput, UpdateInput> {
     constructor() {
       super(prisma, 'yourEntity');
     }

     async findByCustomField(value: string): Promise<YourEntity[]> {
       return this.prisma.yourEntity.findMany({
         where: { customField: value },
       });
     }
   }

   export const yourModuleRepository = new YourModuleRepository();
   ```

3. **Implement Service / Triển khai Service**:
   ```typescript
   // src/modules/your-module/your-module.service.ts
   import { yourModuleRepository } from './your-module.repository';
   import { CreateYourEntityDto, UpdateYourEntityDto } from './your-module.dto';

   export class YourModuleService {
     async create(data: CreateYourEntityDto) {
       // Business logic
       return yourModuleRepository.create(data);
     }

     async findAll() {
       return yourModuleRepository.findAll();
     }
   }
   ```

4. **Implement Controller / Triển khai Controller**:
   ```typescript
   // src/modules/your-module/your-module.controller.ts
   import { Request, Response } from 'express';
   import { asyncHandler } from '../../middlewares/error.middleware';
   import { YourModuleService } from './your-module.service';

   export class YourModuleController {
     private service = new YourModuleService();

     create = asyncHandler(async (req: Request, res: Response) => {
       const result = await this.service.create(req.body);
       res.status(201).json({
         success: true,
         data: result,
         message: 'Created successfully',
         timestamp: new Date().toISOString(),
       });
     });

     findAll = asyncHandler(async (req: Request, res: Response) => {
       const result = await this.service.findAll();
       res.json({
         success: true,
         data: result,
         message: 'Retrieved successfully',
         timestamp: new Date().toISOString(),
       });
     });
   }
   ```

5. **Create Routes / Tạo Routes**:
   ```typescript
   // src/modules/your-module/your-module.module.ts
   import { Router } from 'express';
   import { YourModuleController } from './your-module.controller';
   import { validateDto } from '../../middlewares/validation.middleware';

   export const createYourModuleRouter = (): Router => {
     const router = Router();
     const controller = new YourModuleController();

     router.post('/', validateDto(createYourEntitySchema), controller.create);
     router.get('/', controller.findAll);

     return router;
   };
   ```

6. **Register Routes / Đăng ký Routes**:
   ```typescript
   // src/routes/index.ts
   import { createYourModuleRouter } from '../modules/your-module/your-module.module';

   router.use('/api/v1/your-entities', createYourModuleRouter());
   ```

### Adding Environment Variables / Thêm Biến Môi trường

1. **Update config schema / Cập nhật config schema**:
   ```typescript
   // src/config/app.config.ts
   const envSchema = z.object({
     // ... existing fields
     YOUR_NEW_VARIABLE: z.string().default('default-value'),
   });

   export const appConfig = {
     // ... existing config
     yourNewVariable: config.YOUR_NEW_VARIABLE,
   };
   ```

2. **Update .env files / Cập nhật file .env**:
   ```bash
   # .env.example
   YOUR_NEW_VARIABLE=your-default-value

   # .env.local.example
   YOUR_NEW_VARIABLE=your-local-value
   ```

### Security Best Practices / Thực tiễn Bảo mật

- **Input Validation**: Always validate and sanitize user inputs using Zod
- **Authentication**: Use JWT tokens with reasonable expiration times
- **Authorization**: Implement proper RBAC for your endpoints
- **Rate Limiting**: Protect against abuse with distributed rate limiting
- **HTTPS**: Always use HTTPS in production
- **Secrets**: Never commit secrets to version control
- **Dependencies**: Keep dependencies updated and audit regularly

### Performance Considerations / Lưu ý Performance

- **Database Queries**: Use indexes for frequently queried fields
- **Caching**: Implement Redis caching for expensive operations
- **Connection Pooling**: Configure appropriate connection pool sizes
- **Async Operations**: Use proper async/await patterns
- **Memory Management**: Monitor memory usage and implement cleanup
- **Metrics**: Monitor performance with built-in Prometheus metrics

## Development Guidelines / Hướng dẫn Phát triển

### Comments / Comment Code
- Use bilingual comments for all public APIs and complex logic.
- Format: `EN` first, then `VI`.
- See `.cursor/skills/comment-code/SKILL.md` for details.

### Adding a Module / Thêm Module
1.  Create `src/modules/<name>/`.
2.  Implement `Controller`, `Service`.
3.  Register routes in `src/routes/index.ts`.

### Code Style / Phong cách Code
- Follow the established patterns in existing modules
- Use TypeScript strictly with proper type annotations
- Implement proper error handling with custom error classes
- Add comprehensive tests for all new functionality