TechSL Inventory Management System - Backend

This repository contains the backend implementation of the TechSL Inventory Management System, developed as part of a Rapid Application Development (RAD) group assignment using the MERN stack.

📋 Project Overview

TechSL is a comprehensive inventory management system designed to help manage their products, customers, and orders efficiently. This backend provides a robust REST API that handles authentication, inventory tracking, order processing, and customer management.

Key Features

• 🔐 Authentication & Authorization: JWT-based authentication system for employees and managers
• 📦 Product Management: Complete CRUD operations for inventory items with category organization
• 👥 Customer Management: Customer data management and tracking
• 📊 Order Management: Order processing with detailed order tracking
• 🏷️ Category Management: Product categorization system
• 🔒 Secure API: Protected routes with middleware authentication
• 📱 CORS Enabled: Ready for frontend integration

🛠️ Technology Stack

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB with Mongoose ODM
• Authentication: JSON Web Tokens (JWT)
• Password Hashing: bcrypt
• Environment Management: dotenv
• Development: nodemon for hot reloading
• Cross-Origin: CORS enabled for frontend communication

📁 Project Structure

backend/
├── controllers/           # Business logic controllers
│   ├── authController.js     # Authentication logic
│   ├── productController.js  # Product management
│   ├── customerController.js # Customer management
│   ├── orderController.js    # Order processing
│   └── categoryController.js # Category management
├── models/               # MongoDB data models
│   ├── Employee-Manager.js   # User authentication model
│   ├── Products.js          # Product inventory model
│   ├── Customers.js         # Customer data model
│   ├── Order.js            # Order management model
│   ├── Category.js         # Product category model
│   └── middleware/         # Custom middleware
│       └── authMiddleware.js # JWT authentication middleware
├── routes/               # API route definitions
│   ├── Employee-ManagerRoutes.js # Authentication routes
│   ├── productRoutes.js         # Product API routes
│   ├── customerRoutes.js        # Customer API routes
│   ├── orderRoutes.js          # Order API routes
│   └── categoryRoutes.js       # Category API routes
├── index.js              # Main application entry point
├── package.json          # Project dependencies and scripts
└── .env                  # Environment variables (not in repo)

🚀 Getting Started

Prerequisites

• Node.js (v14 or higher)
• npm or yarn
• MongoDB Atlas account or local MongoDB installation

Installation

1. Clone the repository

   git clone https://github.com/MERN-Assignment/backend.git
   cd backend

2. Install dependencies

   npm install

3. Environment Setup Create a .env file in the root directory with the following variables:

   MONGODB_URI=your_mongodb_connection_string
   PORT=3001
   JWT_SECRET=your_jwt_secret_key

4. Start the development server

   npm start

The server will start on http://localhost:3001 (or your specified PORT).

🔌 API Endpoints

Authentication (/api/employees)

• GET / - Get all employees (protected)
• POST / - Create new employee
• POST /verify - Employee login verification
• GET /:id - Get employee by ID (protected)
• PUT /:id - Update employee (protected)
• DELETE /:id - Delete employee (protected)

Products (/api/products)

• GET / - Get all products
• POST / - Create or update product
• POST /add-sellingprice-date - Create inventory entry
• GET /:id - Get product by ID
• PUT /:id - Update product
• DELETE /:id - Delete product
• PUT /update-inventory/:id - Update product inventory
• GET /check/:productName/:quantity - Check product availability

Customers (/api/customers)

• GET / - Get all customers
• POST / - Create new customer
• GET /:id - Get customer by ID
• PUT /:id - Update customer
• DELETE /:id - Delete customer
• GET /by-customID/:customID - Get customer by custom ID

Orders (/api/orders)

• GET / - Get all orders
• POST / - Create new order
• GET /:id - Get order by ID
• PUT /:id - Update order
• DELETE /:id - Delete order
• GET /:id/details - Get order with details
• POST /with-details - Create order with details

Categories (/api/categories)

• Standard CRUD operations for product categories

🔐 Authentication Flow

1. Employee Registration: Create account via POST /api/employees
2. Login: Authenticate via POST /api/employees/verify
3. Token Usage: Include JWT token in Authorization header: Bearer <token>
4. Protected Routes: Most routes require valid JWT token

Example Authentication

// Login
POST /api/employees/verify
{
  "username": "employee_username",
  "password": "employee_password"
}

// Response
{
  "status": "success",
  "message": "Login successful",
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

// Using token in subsequent requests
Headers: {
  "Authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

💾 Database Models

Employee-Manager

• username: Unique employee identifier
• password: Hashed password for authentication

Product

• productID: Unique product identifier
• productName: Product name
• sellingPrice: Current selling price
• quantity: Available stock quantity
• date: Date of inventory entry
• categoryID: Reference to product category

Customer

• customer_ID: Unique customer identifier
• fName: First name
• lName: Last name
• email: Customer email address
• address: Customer address
• contact_number: Contact phone number

Order

• orderID: Unique order identifier
• orderDate: Date of order creation
• totalPrice: Total order amount
• customer_ID: Reference to customer
• orderDetails: Array of order items with product details

Category

• categoryID: Unique category identifier
• categoryName: Category name

🔧 Development

Scripts

• npm start - Start development server with nodemon
• npm test - Run tests (currently not configured)

Code Style

The project follows standard JavaScript conventions with:

• Consistent async/await usage
• Proper error handling with try-catch blocks
• RESTful API design principles
• Modular architecture with separation of concerns

🚀 Deployment

This backend is designed to be deployed with the corresponding frontend React application to complete the full-stack TechSL inventory management system.

Environment Variables for Production

Ensure the following environment variables are set in your production environment:

• MONGODB_URI: Production MongoDB connection string
• PORT: Server port (defaults to 3001)
• JWT_SECRET: Strong secret key for JWT signing

Note: This is the backend repository only. The complete MERN stack application requires the corresponding React frontend for full functionality.