Dukaan Sahaayak Backend

This is the backend for Dukaan Sahaayak, a smart inventory management system. It provides a robust API to manage products, sales, purchases, customers, vendors, and credit tracking. The application is built with FastAPI and uses a PostgreSQL database. It also integrates with Twilio for sending SMS notifications and Google's Gemini AI for intelligent product extraction from images.

Features

• Product Management: Full CRUD operations for inventory products.
• Transaction Handling: Record and manage sales and purchase transactions.
• User Management: Automatic customer and vendor creation and lookup by phone number.
• Credit Tracking: Udhaar (credit) management for both sales and purchases.
• Financials: Automatic profit and loss calculation for each sale.
• Notifications: Automated SMS bill generation and sending via Twilio.
• AI-Powered Extraction: Intelligent product extraction from bill images using Google Gemini AI.
• API Documentation: Interactive API documentation via Swagger UI.

Technologies Used

• Framework: FastAPI
• Database: PostgreSQL
• ORM: SQLAlchemy
• Data Validation: Pydantic
• SMS Service: Twilio
• AI/ML: Google Gemini
• Server: Uvicorn

Setup and Installation

Follow these steps to get the development environment running.

1. Prerequisites

• Python 3.8+
• PostgreSQL server running.

2. Clone the Repository

git clone <your-repository-url>
cd DukaanSahaayak-server

3. Create and Activate a Virtual Environment

# For macOS/Linux
python3 -m venv venv
source venv/bin/activate

# For Windows
python -m venv venv
venv\Scripts\activate

4. Install Dependencies

First, ensure you have a requirements.txt file. If not, you can create one from your virtual environment once dependencies are installed:

pip freeze > requirements.txt

Then, install the required packages:

pip install -r requirements.txt

5. Set Up Environment Variables

Create a .env file in the root directory of the project and add the following configuration. Replace the placeholder values with your actual credentials.

DATABASE_URL="postgresql://postgres:******@localhost:5432/smartinventory"
TWILIO_ACCOUNT_SID="your_twilio_account_sid"
TWILIO_AUTH_TOKEN="your_twilio_auth_token"
GEMINI_API_KEY="your_gemini_api_key"

6. Run the Application

Start the development server using Uvicorn:

uvicorn app.main:app --reload

The API will be available at http://127.0.0.1:8000.

API Endpoints

The API is structured with the following tags. You can access the interactive API documentation (Swagger UI) at http://127.0.0.1:8000/docs.

• /api/products/: Manage inventory products.
• /api/sales/: Record and retrieve sales data.
• /api/purchases/: Record and retrieve purchase data.
• /api/customers/: Manage customer information.
• /api/vendors/: Manage vendor information.
• /api/udhaar/: Track credit for sales and purchases.
• /api/profit-loss/: View profit and loss records.
• /api/extract-products/: Extract products from an uploaded image.

Database Schema

The application uses SQLAlchemy to define the database models. The main tables are:

• customers: Stores customer details (cust_id, customer_name, phone_no).
• vendors: Stores vendor details (vend_id, vendor_name, phone_no).
• products: Stores product inventory information (product_id, product_name, price_purchase, price_sale, quantity).
• sales_data: Records sales transactions.
• purchase_data: Records purchase transactions.
• profit_loss: Tracks profit or loss for each sale.
• udhar_sales: Manages credit given to customers.
• udhar_purchase: Manages credit received from vendors.
• sale_product & purchase_product: Association tables linking transactions to products.