# Small Business Inventory System

A comprehensive inventory management system for small businesses built with Python and FastAPI.

## Features

- **User Management**: Secure authentication with JWT tokens and role-based access control
- **Inventory Management**: Complete CRUD operations for inventory items with SKU and barcode support
- **Category Management**: Organize inventory items by categories
- **Supplier Management**: Track supplier information and relationships
- **Stock Tracking**: Real-time stock levels with low stock alerts
- **Transaction History**: Track all inventory movements (in/out/adjustments)
- **Search & Filter**: Advanced search and filtering capabilities
- **RESTful API**: Well-documented API endpoints with automatic OpenAPI documentation

## Tech Stack

- **Framework**: FastAPI
- **Database**: SQLite with SQLAlchemy ORM
- **Authentication**: JWT tokens with bcrypt password hashing
- **Migrations**: Alembic for database schema management
- **Documentation**: Automatic API documentation with Swagger UI

## Installation & Setup

1. Install dependencies:
   ```bash
   pip install -r requirements.txt
   ```

2. Set up environment variables (optional):
   ```bash
   export SECRET_KEY="your-secret-key-here"
   export ADMIN_EMAIL="admin@yourcompany.com"
   export ADMIN_PASSWORD="secure-admin-password"
   ```

3. Run the application:
   ```bash
   uvicorn main:app --host 0.0.0.0 --port 8000 --reload
   ```

## Environment Variables

The following environment variables can be set:

- `SECRET_KEY`: JWT secret key (defaults to development key - change in production!)
- `ADMIN_EMAIL`: Initial admin user email (default: admin@example.com)
- `ADMIN_PASSWORD`: Initial admin user password (default: admin123)

**⚠️ Important**: Change the `SECRET_KEY`, `ADMIN_EMAIL`, and `ADMIN_PASSWORD` environment variables in production!

## API Documentation

Once the application is running, you can access:

- **Swagger UI**: http://localhost:8000/docs
- **ReDoc**: http://localhost:8000/redoc
- **OpenAPI JSON**: http://localhost:8000/openapi.json
- **Health Check**: http://localhost:8000/health

## API Endpoints

### Authentication
- `POST /api/v1/auth/login` - Login and get access token

### Users
- `GET /api/v1/users/me` - Get current user info
- `GET /api/v1/users/` - List all users (admin only)
- `POST /api/v1/users/` - Create new user (admin only)

### Categories
- `GET /api/v1/categories/` - List all categories
- `POST /api/v1/categories/` - Create new category
- `PUT /api/v1/categories/{id}` - Update category
- `DELETE /api/v1/categories/{id}` - Delete category

### Suppliers
- `GET /api/v1/suppliers/` - List all suppliers
- `POST /api/v1/suppliers/` - Create new supplier
- `PUT /api/v1/suppliers/{id}` - Update supplier
- `DELETE /api/v1/suppliers/{id}` - Delete supplier

### Inventory
- `GET /api/v1/inventory/` - List inventory items (with search/filter options)
- `GET /api/v1/inventory/low-stock` - Get low stock items
- `POST /api/v1/inventory/` - Create new inventory item
- `GET /api/v1/inventory/{id}` - Get inventory item by ID
- `GET /api/v1/inventory/sku/{sku}` - Get inventory item by SKU
- `PUT /api/v1/inventory/{id}` - Update inventory item
- `DELETE /api/v1/inventory/{id}` - Delete inventory item

### Transactions
- `GET /api/v1/transactions/` - List inventory transactions
- `POST /api/v1/transactions/` - Create new transaction (updates stock levels)
- `GET /api/v1/transactions/{id}` - Get transaction by ID

## Database Schema

The system uses SQLite with the following main entities:

- **Users**: System users with authentication
- **Categories**: Item categories for organization
- **Suppliers**: Supplier information and contacts
- **InventoryItems**: Main inventory items with pricing and stock info
- **InventoryTransactions**: Track all stock movements

## Development

- **Linting**: The project uses Ruff for code linting and formatting
- **Database**: SQLite database stored in `/app/storage/db/`
- **Migrations**: Use Alembic for database schema changes

## Default Admin User

The system creates a default admin user on first run:
- **Email**: admin@example.com (or value from `ADMIN_EMAIL` env var)
- **Password**: admin123 (or value from `ADMIN_PASSWORD` env var)

**⚠️ Security Note**: Change the default admin credentials immediately in production!