# Royal Enfield Workflow Management System - Backend

A comprehensive backend API for the Royal Enfield Workflow Management System built with Node.js, TypeScript, Express.js, and PostgreSQL.

## Features

- **Frontend SSO Integration**: Handles user authentication via frontend SSO
- **JWT Authentication**: Secure token-based authentication with refresh tokens
- **User Management**: Create and update users based on SSO data
- **Workflow Management**: Complete workflow request lifecycle
- **Approval System**: Multi-level approval workflow
- **Document Management**: File upload and management
- **Notification System**: Real-time notifications
- **TAT Tracking**: Turnaround time monitoring
- **Audit Logging**: Comprehensive activity tracking
- **RESTful API**: Well-structured API endpoints

## Technology Stack

- **Runtime**: Node.js 22 LTS
- **Language**: TypeScript 5.7
- **Framework**: Express.js 4.21
- **Database**: PostgreSQL 16
- **ORM**: Sequelize 6.37
- **Authentication**: JWT + Frontend SSO
- **Validation**: Zod
- **Logging**: Winston
- **Testing**: Jest + Supertest
- **Process Manager**: PM2

## Quick Start

### Prerequisites

- Node.js 22.x LTS
- PostgreSQL 16.x
- npm 10.x or higher

### Installation

1. **Clone the repository**
   ```bash
   git clone <repository-url>
   cd re-workflow-backend
   ```

2. **Install dependencies**
   ```bash
   npm install
   ```

3. **Setup environment**
   ```bash
   cp env.example .env
   # Edit .env with your configuration
   ```

4. **Setup database**
   ```bash
   # Create database
   createdb re_workflow_db
   
   # Run schema
   psql -U postgres -d re_workflow_db -f database/schema/schema.sql
   ```

5. **Start development server**
   ```bash
   npm run dev
   ```

The API will be available at `http://localhost:5000`

### Docker Setup

```bash
# Copy environment file
cp env.example .env

# Start services
docker-compose up --build -d

# Check logs
docker-compose logs -f
```

## API Endpoints

### Authentication
- `POST /api/v1/auth/sso-callback` - SSO callback from frontend
- `GET /api/v1/auth/me` - Get current user profile
- `POST /api/v1/auth/refresh` - Refresh access token
- `POST /api/v1/auth/logout` - Logout user
- `GET /api/v1/auth/validate` - Validate token

### Health Check
- `GET /health` - API health status
- `GET /api/v1/health` - Detailed health check

## Environment Variables

See `env.example` for all required environment variables.

## Development

```bash
# Run in development mode
npm run dev

# Run tests
npm test

# Run linting
npm run lint

# Run type checking
npm run type-check

# Build for production
npm run build
```

## Project Structure

```
src/
├── app.ts                 # Express app configuration
├── server.ts              # Server entry point
├── config/                # Configuration files
├── controllers/           # Request handlers
├── services/              # Business logic
├── models/                # Sequelize models
├── routes/                # API routes
├── middlewares/           # Express middlewares
├── validators/            # Request validation schemas
├── utils/                 # Utility functions
└── types/                 # TypeScript type definitions
```

## Database Schema

The database schema includes all tables from the ERD:
- `users` - User information
- `workflow_requests` - Main workflow requests
- `approval_levels` - Approval hierarchy
- `participants` - Workflow participants
- `documents` - Document metadata
- `work_notes` - Communication within workflow
- `activities` - Activity log
- `notifications` - User notifications
- `tat_tracking` - TAT monitoring
- And more...

## Authentication Flow

1. Frontend handles SSO authentication
2. Frontend sends user data to `/api/v1/auth/sso-callback`
3. Backend creates/updates user record
4. Backend generates JWT tokens
5. Frontend uses tokens for subsequent API calls

## Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run tests and linting
5. Submit a pull request

## License

This project is proprietary to Royal Enfield.

## Support

For support and questions, please contact the development team.