Invoice and Daily Sales Report System

This project consists of two microservices:

1. Invoice Service: Handles invoice creation and generates daily sales reports
2. Email Service: Consumes daily sales reports and sends them via email

Prerequisites

• Node.js (v18 or later)
• Docker and Docker Compose
• MongoDB
• RabbitMQ

Project Structure

.
├── docker-compose.yml
├── invoice-service/
│   ├── src/
│   │   ├── invoice/
│   │   ├── report/
│   │   ├── app.module.ts
│   │   └── main.ts
│   ├── Dockerfile
│   ├── package.json
│   └── tsconfig.json
└── email-service/
    ├── src/
    │   ├── email/
    │   ├── app.module.ts
    │   └── main.ts
    ├── Dockerfile
    ├── package.json
    └── tsconfig.json

Setup and Installation

1. Clone the repository:

git clone <repository-url>
cd invoice-service

2. Install dependencies for both services:

cd invoice-service && npm install
cd ../email-service && npm install

3. Configure environment variables:

• Create .env files in both service directories with the following variables:

For invoice-service:

MONGODB_URI=mongodb://root:example@mongodb:27017/invoice?authSource=admin
RABBITMQ_URL=amqp://user:password@rabbitmq:5672

For email-service:

RABBITMQ_URL=amqp://user:password@rabbitmq:5672
SMTP_HOST=smtp.example.com
SMTP_PORT=587
SMTP_USER=[email protected]
SMTP_PASS=password

4. Start the services using Docker Compose:

docker-compose up --build

API Endpoints

Invoice Service (http://localhost:3000)

• POST /invoices - Create a new invoice

  {
    "customer": "John Doe",
    "amount": 100,
    "reference": "INV001",
    "date": "2024-01-01T00:00:00.000Z",
    "items": [
      {
        "sku": "SKU001",
        "qt": 2
      }
    ]
  }

• GET /invoices - Get all invoices

• GET /invoices/:id - Get a specific invoice

• GET /invoices/range?startDate=2024-01-01&endDate=2024-01-02 - Get invoices within a date range

Features

1. Invoice Creation:

   • Create invoices with customer details, amount, and items
   • Store invoices in MongoDB
   • RESTful API for invoice management

2. Daily Sales Report:

   • Automatically generates daily sales reports at 12:00 PM
   • Calculates total sales and item-wise quantities
   • Publishes reports to RabbitMQ queue

3. Email Service:

   • Consumes reports from RabbitMQ queue
   • Sends formatted email reports
   • Configurable email settings

Testing

Run tests for each service:

# In invoice-service directory
npm test

# In email-service directory
npm test

Architecture

The system uses a microservices architecture with:

• NestJS for both services
• MongoDB for invoice storage
• RabbitMQ for message queuing
• Docker for containerization
• Jest for testing

Error Handling

• Both services include comprehensive error handling
• Failed operations are logged
• RabbitMQ ensures message persistence
• Email sending retries on failure

Monitoring

• Console logging for important operations
• RabbitMQ management interface (http://localhost:15672)
• MongoDB logs

Contributing

1. Fork the repository
2. Create your feature branch
3. Commit your changes
4. Push to the branch
5. Create a new Pull Request