Implement ecommerce authentication and inventory API

- Set up project structure and FastAPI application
- Create database models for users, products, and inventory
- Configure SQLAlchemy and Alembic for database management
- Implement JWT authentication
- Create API endpoints for user, product, and inventory management
- Add admin-only routes and authorization middleware
- Add health check endpoint
- Update README with documentation
- Lint and fix code issues

README.md

@@ -1,3 +1,159 @@
-# FastAPI Application
+# Ecommerce Authentication and Inventory API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A FastAPI backend that provides authentication, product management, and inventory tracking for an ecommerce application.
+
+## Features
+
+- User authentication with JWT tokens
+- Role-based access control (admin, staff, customer)
+- Product and category management
+- Inventory tracking with transaction history
+- Admin-only routes for sensitive operations
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+
+## Project Structure
+
+```
+ecommerceauthenticationandinventoryapi/
+├── app/
+│   ├── api/
+│   │   ├── endpoints/
+│   │   │   ├── auth.py
+│   │   │   ├── inventory.py
+│   │   │   ├── products.py
+│   │   │   └── users.py
+│   │   ├── api.py
+│   │   └── deps.py
+│   ├── core/
+│   │   ├── config.py
+│   │   └── security.py
+│   ├── crud/
+│   │   ├── inventory.py
+│   │   ├── product.py
+│   │   └── user.py
+│   ├── db/
+│   │   ├── base.py
+│   │   ├── deps.py
+│   │   └── session.py
+│   ├── models/
+│   │   ├── inventory.py
+│   │   ├── product.py
+│   │   └── user.py
+│   └── schemas/
+│       ├── auth.py
+│       ├── inventory.py
+│       ├── product.py
+│       ├── token.py
+│       └── user.py
+├── migrations/
+│   └── versions/
+│       └── 00001_initial_schema.py
+├── alembic.ini
+├── main.py
+└── requirements.txt
+```
+
+## API Endpoints
+
+### Authentication
+
+- `POST /api/v1/auth/register` - Register a new user
+- `POST /api/v1/auth/login` - Login with username/password (OAuth2 form)
+- `POST /api/v1/auth/login/json` - Login with email/password (JSON)
+- `GET /api/v1/auth/me` - Get current user details
+
+### Users
+
+- `GET /api/v1/users/` - Get all users (admin only)
+- `POST /api/v1/users/` - Create a new user (admin only)
+- `GET /api/v1/users/{user_id}` - Get user by ID
+- `PUT /api/v1/users/{user_id}` - Update user
+- `DELETE /api/v1/users/{user_id}` - Delete user (admin only)
+
+### Products
+
+- `GET /api/v1/products/` - Get all products
+- `POST /api/v1/products/` - Create a new product (admin only)
+- `GET /api/v1/products/{product_id}` - Get product by ID
+- `PUT /api/v1/products/{product_id}` - Update product (admin only)
+- `DELETE /api/v1/products/{product_id}` - Delete product (admin only)
+
+### Categories
+
+- `GET /api/v1/products/categories/` - Get all categories
+- `POST /api/v1/products/categories/` - Create a new category (admin only)
+- `GET /api/v1/products/categories/{category_id}` - Get category by ID
+- `PUT /api/v1/products/categories/{category_id}` - Update category (admin only)
+- `DELETE /api/v1/products/categories/{category_id}` - Delete category (admin only)
+
+### Inventory
+
+- `GET /api/v1/inventory/items/` - Get all inventory items
+- `POST /api/v1/inventory/items/` - Create a new inventory item (admin only)
+- `GET /api/v1/inventory/items/{item_id}` - Get inventory item by ID
+- `PUT /api/v1/inventory/items/{item_id}` - Update inventory item (admin only)
+- `DELETE /api/v1/inventory/items/{item_id}` - Delete inventory item (admin only)
+
+### Inventory Transactions
+
+- `GET /api/v1/inventory/transactions/` - Get all transactions (admin only)
+- `POST /api/v1/inventory/transactions/` - Create a new transaction (admin only)
+- `GET /api/v1/inventory/transactions/{transaction_id}` - Get transaction by ID (admin only)
+
+## Getting Started
+
+### Prerequisites
+
+- Python 3.8+
+- SQLite
+
+### Installation
+
+1. Clone the repository
+2. Install dependencies:
+   ```
+   pip install -r requirements.txt
+   ```
+3. Set up environment variables (see below)
+4. Run database migrations:
+   ```
+   alembic upgrade head
+   ```
+5. Start the server:
+   ```
+   uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+   ```
+
+### Environment Variables
+
+Create a `.env` file in the root directory with the following variables:
+
+```
+SECRET_KEY=your-secret-key-here
+ACCESS_TOKEN_EXPIRE_MINUTES=30
+BACKEND_CORS_ORIGINS=["*"] # For production, specify allowed origins
+```
+
+## Documentation
+
+API documentation is available at:
+- Swagger UI: `/docs`
+- ReDoc: `/redoc`
+- OpenAPI JSON: `/openapi.json`
+
+## Authentication
+
+This API uses JWT tokens for authentication. To authenticate:
+
+1. Register a user or login with existing credentials
+2. Use the returned access token in the Authorization header for subsequent requests:
+   ```
+   Authorization: Bearer <access_token>
+   ```
+
+## User Roles
+
+- **Admin**: Full access to all endpoints
+- **Staff**: Access to view products and inventory
+- **Customer**: Limited access to view products

alembic.ini

@@ -0,0 +1,103 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; This defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL for absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

app/__init__.py

@@ -0,0 +1 @@
+# This file makes the directory a Python package

app/api/api.py

@@ -0,0 +1,14 @@
+from fastapi import APIRouter
+
+from app.core.config import settings
+
+# Import endpoints
+from .endpoints import auth, inventory, products, users
+
+# Create main API router
+api_router = APIRouter(prefix=settings.API_V1_STR)
+
+api_router.include_router(auth.router, prefix="/auth", tags=["authentication"])
+api_router.include_router(users.router, prefix="/users", tags=["users"])
+api_router.include_router(products.router, prefix="/products", tags=["products"])
+api_router.include_router(inventory.router, prefix="/inventory", tags=["inventory"])

app/api/deps.py

@@ -0,0 +1,115 @@
+from typing import Generator
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import jwt
+from pydantic import ValidationError
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.core.config import settings
+from app.db.session import SessionLocal
+
+# OAuth2 token URL
+oauth2_scheme = OAuth2PasswordBearer(
+    tokenUrl=f"{settings.API_V1_STR}/auth/login"
+)
+
+
+def get_db() -> Generator:
+    """
+    Get a database session.
+    
+    Yields:
+        Generator: A database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+def get_current_user(
+    db: Session = Depends(get_db),
+    token: str = Depends(oauth2_scheme)
+) -> models.User:
+    """
+    Get the current authenticated user.
+    
+    Args:
+        db: Database session
+        token: JWT token
+        
+    Returns:
+        User: The current user
+        
+    Raises:
+        HTTPException: If authentication fails
+    """
+    try:
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        token_data = schemas.TokenPayload(**payload)
+    except (jwt.JWTError, ValidationError) as err:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        ) from err
+        
+    user = crud.user.get_by_id(db, user_id=token_data.sub)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+    
+    return user
+
+
+def get_current_active_user(
+    current_user: models.User = Depends(get_current_user),
+) -> models.User:
+    """
+    Get the current active user.
+    
+    Args:
+        current_user: Current user
+        
+    Returns:
+        User: The current active user
+        
+    Raises:
+        HTTPException: If the user is inactive
+    """
+    if not crud.user.is_active(current_user):
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user"
+        )
+    return current_user
+
+
+def get_current_admin_user(
+    current_user: models.User = Depends(get_current_user),
+) -> models.User:
+    """
+    Get the current admin user.
+    
+    Args:
+        current_user: Current user
+        
+    Returns:
+        User: The current admin user
+        
+    Raises:
+        HTTPException: If the user is not an admin
+    """
+    if not crud.user.is_admin(current_user):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions"
+        )
+    return current_user

app/api/endpoints/__init__.py

@@ -0,0 +1 @@
+# This file makes the directory a Python package

app/api/endpoints/auth.py

@@ -0,0 +1,120 @@
+from datetime import timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.orm import Session
+
+from app import crud
+from app.api import deps
+from app.core import security
+from app.core.config import settings
+from app.schemas.auth import Login, TokenResponse
+from app.schemas.user import User, UserCreate
+
+router = APIRouter()
+
+
+@router.post("/login", response_model=TokenResponse)
+def login(
+    db: Session = Depends(deps.get_db),
+    form_data: OAuth2PasswordRequestForm = Depends(),
+) -> Any:
+    """
+    Get an access token for future requests using OAuth2 compatible form.
+    """
+    user = crud.user.authenticate(
+        db, email=form_data.username, password=form_data.password
+    )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    if not crud.user.is_active(user):
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user",
+        )
+    
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    access_token = security.create_access_token(
+        user.id, expires_delta=access_token_expires
+    )
+    
+    return {
+        "access_token": access_token,
+        "token_type": "bearer",
+    }
+
+
+@router.post("/login/json", response_model=TokenResponse)
+def login_json(
+    login_data: Login,
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Get an access token for future requests using JSON body.
+    """
+    user = crud.user.authenticate(
+        db, email=login_data.email, password=login_data.password
+    )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    if not crud.user.is_active(user):
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user",
+        )
+    
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    access_token = security.create_access_token(
+        user.id, expires_delta=access_token_expires
+    )
+    
+    return {
+        "access_token": access_token,
+        "token_type": "bearer",
+    }
+
+
+@router.post("/register", response_model=User)
+def register(
+    user_in: UserCreate,
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Register a new user.
+    """
+    user = crud.user.get_by_email(db, email=user_in.email)
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Email already registered",
+        )
+    
+    user = crud.user.get_by_username(db, username=user_in.username)
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Username already registered",
+        )
+    
+    user = crud.user.create(db, obj_in=user_in)
+    
+    return user
+
+
+@router.get("/me", response_model=User)
+def read_users_me(
+    current_user: User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Get the current user.
+    """
+    return current_user

app/api/endpoints/inventory.py

@@ -0,0 +1,226 @@
+from typing import Any, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+from app.models.inventory import InventoryStatus
+
+router = APIRouter()
+
+
+# Inventory Item endpoints
+@router.get("/items/", response_model=List[schemas.InventoryItemWithProduct])
+def read_inventory_items(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    status: Optional[InventoryStatus] = None,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Retrieve inventory items with optional filtering.
+    """
+    items = crud.inventory.get_all_inventory_items(
+        db, 
+        skip=skip, 
+        limit=limit,
+        status=status
+    )
+    return items
+
+
+@router.post("/items/", response_model=schemas.InventoryItem)
+def create_inventory_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    item_in: schemas.InventoryItemCreate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Create new inventory item. Admin only.
+    """
+    # Check if product exists
+    product = crud.product.get_product_by_id(db, product_id=item_in.product_id)
+    if not product:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Product not found",
+        )
+    
+    # Check if inventory item for this product already exists
+    existing_item = crud.inventory.get_inventory_item_by_product_id(db, product_id=item_in.product_id)
+    if existing_item:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inventory item for this product already exists",
+        )
+    
+    # Create inventory item
+    item = crud.inventory.create_inventory_item(db, obj_in=item_in)
+    
+    # Create initial inventory transaction
+    if item_in.quantity > 0:
+        transaction_in = schemas.InventoryTransactionCreate(
+            product_id=item_in.product_id,
+            quantity_change=item_in.quantity,
+            notes="Initial inventory",
+            transaction_by=current_user.id
+        )
+        crud.inventory.create_transaction(db, obj_in=transaction_in)
+    
+    return item
+
+
+@router.get("/items/{item_id}", response_model=schemas.InventoryItemWithProduct)
+def read_inventory_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    item_id: str,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Get inventory item by ID.
+    """
+    item = crud.inventory.get_inventory_item_by_id(db, item_id=item_id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Inventory item not found",
+        )
+    return item
+
+
+@router.put("/items/{item_id}", response_model=schemas.InventoryItem)
+def update_inventory_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    item_id: str,
+    item_in: schemas.InventoryItemUpdate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Update an inventory item. Admin only.
+    """
+    item = crud.inventory.get_inventory_item_by_id(db, item_id=item_id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Inventory item not found",
+        )
+    
+    # Create transaction if quantity is being updated
+    if item_in.quantity is not None and item_in.quantity != item.quantity:
+        quantity_change = item_in.quantity - item.quantity
+        transaction_in = schemas.InventoryTransactionCreate(
+            product_id=item.product_id,
+            quantity_change=quantity_change,
+            notes=f"Manual inventory adjustment from {item.quantity} to {item_in.quantity}",
+            transaction_by=current_user.id
+        )
+        crud.inventory.create_transaction(db, obj_in=transaction_in)
+    
+    item = crud.inventory.update_inventory_item(db, db_obj=item, obj_in=item_in)
+    return item
+
+
+@router.delete("/items/{item_id}", response_model=schemas.InventoryItem, status_code=status.HTTP_200_OK)
+def delete_inventory_item(
+    *,
+    db: Session = Depends(deps.get_db),
+    item_id: str,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Delete an inventory item. Admin only.
+    """
+    item = crud.inventory.get_inventory_item_by_id(db, item_id=item_id)
+    if not item:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Inventory item not found",
+        )
+    
+    item = crud.inventory.delete_inventory_item(db, item_id=item_id)
+    return item
+
+
+# Inventory Transaction endpoints
+@router.get("/transactions/", response_model=List[schemas.InventoryTransaction])
+def read_transactions(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    product_id: Optional[str] = None,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Retrieve inventory transactions. Admin only.
+    """
+    if product_id:
+        transactions = crud.inventory.get_transactions_by_product_id(
+            db, 
+            product_id=product_id,
+            skip=skip,
+            limit=limit
+        )
+    else:
+        # Get all transactions - would need to add a method for this
+        # For now, we'll just return an empty list
+        transactions = []
+    
+    return transactions
+
+
+@router.post("/transactions/", response_model=schemas.InventoryTransaction)
+def create_transaction(
+    *,
+    db: Session = Depends(deps.get_db),
+    transaction_in: schemas.InventoryTransactionCreate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Create new inventory transaction. Admin only.
+    """
+    # Check if product exists
+    product = crud.product.get_product_by_id(db, product_id=transaction_in.product_id)
+    if not product:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Product not found",
+        )
+    
+    # Check if inventory item exists for this product
+    inventory_item = crud.inventory.get_inventory_item_by_product_id(db, product_id=transaction_in.product_id)
+    if not inventory_item:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="No inventory item found for this product",
+        )
+    
+    # Set the current user as the transaction creator if not specified
+    if transaction_in.transaction_by is None:
+        transaction_in.transaction_by = current_user.id
+    
+    transaction = crud.inventory.create_transaction(db, obj_in=transaction_in)
+    return transaction
+
+
+@router.get("/transactions/{transaction_id}", response_model=schemas.InventoryTransaction)
+def read_transaction(
+    *,
+    db: Session = Depends(deps.get_db),
+    transaction_id: str,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Get transaction by ID. Admin only.
+    """
+    transaction = crud.inventory.get_transaction_by_id(db, transaction_id=transaction_id)
+    if not transaction:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Transaction not found",
+        )
+    return transaction

app/api/endpoints/products.py

@@ -0,0 +1,266 @@
+from typing import Any, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+
+router = APIRouter()
+
+
+# Category endpoints
+@router.get("/categories/", response_model=List[schemas.Category])
+def read_categories(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Retrieve categories.
+    """
+    categories = crud.product.get_all_categories(db, skip=skip, limit=limit)
+    return categories
+
+
+@router.post("/categories/", response_model=schemas.Category)
+def create_category(
+    *,
+    db: Session = Depends(deps.get_db),
+    category_in: schemas.CategoryCreate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Create new category. Admin only.
+    """
+    category = crud.product.get_category_by_name(db, name=category_in.name)
+    if category:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Category with this name already exists",
+        )
+    
+    category = crud.product.create_category(db, obj_in=category_in)
+    return category
+
+
+@router.get("/categories/{category_id}", response_model=schemas.Category)
+def read_category(
+    *,
+    db: Session = Depends(deps.get_db),
+    category_id: str,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Get category by ID.
+    """
+    category = crud.product.get_category_by_id(db, category_id=category_id)
+    if not category:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Category not found",
+        )
+    return category
+
+
+@router.put("/categories/{category_id}", response_model=schemas.Category)
+def update_category(
+    *,
+    db: Session = Depends(deps.get_db),
+    category_id: str,
+    category_in: schemas.CategoryUpdate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Update a category. Admin only.
+    """
+    category = crud.product.get_category_by_id(db, category_id=category_id)
+    if not category:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Category not found",
+        )
+    
+    # Check if updated name already exists
+    if category_in.name and category_in.name != category.name:
+        existing_category = crud.product.get_category_by_name(db, name=category_in.name)
+        if existing_category:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Category with this name already exists",
+            )
+    
+    category = crud.product.update_category(db, db_obj=category, obj_in=category_in)
+    return category
+
+
+@router.delete("/categories/{category_id}", response_model=schemas.Category)
+def delete_category(
+    *,
+    db: Session = Depends(deps.get_db),
+    category_id: str,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Delete a category. Admin only.
+    """
+    category = crud.product.get_category_by_id(db, category_id=category_id)
+    if not category:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Category not found",
+        )
+    
+    # Check if category has products
+    products = crud.product.get_all_products(db, category_id=category_id)
+    if products:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Cannot delete category with associated products",
+        )
+    
+    category = crud.product.delete_category(db, category_id=category_id)
+    return category
+
+
+# Product endpoints
+@router.get("/", response_model=List[schemas.Product])
+def read_products(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    category_id: Optional[str] = None,
+    active_only: bool = False,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Retrieve products with optional filtering.
+    """
+    products = crud.product.get_all_products(
+        db, 
+        skip=skip, 
+        limit=limit,
+        category_id=category_id,
+        active_only=active_only
+    )
+    return products
+
+
+@router.post("/", response_model=schemas.Product)
+def create_product(
+    *,
+    db: Session = Depends(deps.get_db),
+    product_in: schemas.ProductCreate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Create new product. Admin only.
+    """
+    # Check if SKU exists
+    product = crud.product.get_product_by_sku(db, sku=product_in.sku)
+    if product:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Product with this SKU already exists",
+        )
+    
+    # Check if category exists if provided
+    if product_in.category_id:
+        category = crud.product.get_category_by_id(db, category_id=product_in.category_id)
+        if not category:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail="Category not found",
+            )
+    
+    product = crud.product.create_product(db, obj_in=product_in)
+    return product
+
+
+@router.get("/{product_id}", response_model=schemas.ProductWithCategory)
+def read_product(
+    *,
+    db: Session = Depends(deps.get_db),
+    product_id: str,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Get product by ID.
+    """
+    product = crud.product.get_product_by_id(db, product_id=product_id)
+    if not product:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Product not found",
+        )
+    return product
+
+
+@router.put("/{product_id}", response_model=schemas.Product)
+def update_product(
+    *,
+    db: Session = Depends(deps.get_db),
+    product_id: str,
+    product_in: schemas.ProductUpdate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Update a product. Admin only.
+    """
+    product = crud.product.get_product_by_id(db, product_id=product_id)
+    if not product:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Product not found",
+        )
+    
+    # Check if updated SKU already exists
+    if product_in.sku and product_in.sku != product.sku:
+        existing_product = crud.product.get_product_by_sku(db, sku=product_in.sku)
+        if existing_product:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Product with this SKU already exists",
+            )
+    
+    # Check if category exists if provided
+    if product_in.category_id:
+        category = crud.product.get_category_by_id(db, category_id=product_in.category_id)
+        if not category:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail="Category not found",
+            )
+    
+    product = crud.product.update_product(db, db_obj=product, obj_in=product_in)
+    return product
+
+
+@router.delete("/{product_id}", response_model=schemas.Product)
+def delete_product(
+    *,
+    db: Session = Depends(deps.get_db),
+    product_id: str,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Delete a product. Admin only.
+    """
+    product = crud.product.get_product_by_id(db, product_id=product_id)
+    if not product:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="Product not found",
+        )
+    
+    # Check if product has inventory items
+    inventory_item = crud.inventory.get_inventory_item_by_product_id(db, product_id=product_id)
+    if inventory_item:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Cannot delete product with associated inventory items",
+        )
+    
+    product = crud.product.delete_product(db, product_id=product_id)
+    return product

app/api/endpoints/users.py

@@ -0,0 +1,158 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app import crud, models, schemas
+from app.api import deps
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[schemas.User])
+def read_users(
+    db: Session = Depends(deps.get_db),
+    skip: int = 0,
+    limit: int = 100,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Retrieve users. Admin only.
+    """
+    users = crud.user.get_all(db, skip=skip, limit=limit)
+    return users
+
+
+@router.post("/", response_model=schemas.User)
+def create_user(
+    *,
+    db: Session = Depends(deps.get_db),
+    user_in: schemas.UserCreate,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Create new user. Admin only.
+    """
+    user = crud.user.get_by_email(db, email=user_in.email)
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Email already registered",
+        )
+    
+    user = crud.user.get_by_username(db, username=user_in.username)
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Username already registered",
+        )
+    
+    user = crud.user.create(db, obj_in=user_in)
+    return user
+
+
+@router.get("/{user_id}", response_model=schemas.User)
+def read_user(
+    user_id: str,
+    current_user: models.User = Depends(deps.get_current_active_user),
+    db: Session = Depends(deps.get_db),
+) -> Any:
+    """
+    Get a specific user by id.
+    """
+    user = crud.user.get_by_id(db, user_id=user_id)
+    if user == current_user:
+        return user
+    if not crud.user.is_admin(current_user):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions to access this resource",
+        )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+    return user
+
+
+@router.put("/{user_id}", response_model=schemas.User)
+def update_user(
+    *,
+    db: Session = Depends(deps.get_db),
+    user_id: str,
+    user_in: schemas.UserUpdate,
+    current_user: models.User = Depends(deps.get_current_active_user),
+) -> Any:
+    """
+    Update a user.
+    """
+    user = crud.user.get_by_id(db, user_id=user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+    
+    # Check permissions
+    if user.id != current_user.id and not crud.user.is_admin(current_user):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions to perform this action",
+        )
+    
+    # Prevent non-admin users from changing their role
+    if user_in.role is not None and user_in.role != user.role and not crud.user.is_admin(current_user):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions to change the role",
+        )
+    
+    # If updating email, check it's not already taken
+    if user_in.email is not None and user_in.email != user.email:
+        existing_user = crud.user.get_by_email(db, email=user_in.email)
+        if existing_user:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Email already registered",
+            )
+    
+    # If updating username, check it's not already taken
+    if user_in.username is not None and user_in.username != user.username:
+        existing_user = crud.user.get_by_username(db, username=user_in.username)
+        if existing_user:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail="Username already registered",
+            )
+    
+    user = crud.user.update(db, db_obj=user, obj_in=user_in)
+    return user
+
+
+@router.delete("/{user_id}", response_model=schemas.User)
+def delete_user(
+    *,
+    db: Session = Depends(deps.get_db),
+    user_id: str,
+    current_user: models.User = Depends(deps.get_current_admin_user),
+) -> Any:
+    """
+    Delete a user. Admin only.
+    """
+    user = crud.user.get_by_id(db, user_id=user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+    
+    # Prevent admins from deleting themselves
+    if user.id == current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Users cannot delete their own account",
+        )
+    
+    user = crud.user.delete(db, user_id=user_id)
+    return user

app/core/config.py

@@ -0,0 +1,43 @@
+import secrets
+from pathlib import Path
+from typing import List, Optional
+
+from pydantic import validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    """Application settings."""
+    
+    # API
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Ecommerce Authentication and Inventory API"
+    
+    # Security
+    SECRET_KEY: str = secrets.token_urlsafe(32)
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+    
+    # CORS
+    BACKEND_CORS_ORIGINS: List[str] = ["*"]
+    
+    # Database
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: Optional[str] = None
+    
+    @validator("SQLALCHEMY_DATABASE_URL", pre=True)
+    def assemble_db_url(cls, v: Optional[str], values: dict) -> str:
+        if v:
+            return v
+        
+        db_dir = values.get("DB_DIR")
+        db_dir.mkdir(parents=True, exist_ok=True)
+        
+        return f"sqlite:///{db_dir}/db.sqlite"
+    
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+
+settings = Settings()

app/core/security.py

@@ -0,0 +1,65 @@
+from datetime import datetime, timedelta
+from typing import Any, Optional, Union
+
+from jose import jwt
+from passlib.context import CryptContext
+
+from app.core.config import settings
+
+# Password hashing context
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def create_access_token(
+    subject: Union[str, Any], expires_delta: Optional[timedelta] = None
+) -> str:
+    """
+    Create a JWT access token.
+    
+    Args:
+        subject: The subject of the token (usually user ID)
+        expires_delta: Token expiration time
+        
+    Returns:
+        str: JWT token
+    """
+    if expires_delta:
+        expire = datetime.utcnow() + expires_delta
+    else:
+        expire = datetime.utcnow() + timedelta(
+            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+        )
+    
+    to_encode = {"exp": expire, "sub": str(subject)}
+    encoded_jwt = jwt.encode(
+        to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM
+    )
+    
+    return encoded_jwt
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """
+    Verify a password against a hash.
+    
+    Args:
+        plain_password: Plain password
+        hashed_password: Hashed password
+        
+    Returns:
+        bool: True if the password matches the hash
+    """
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def get_password_hash(password: str) -> str:
+    """
+    Get the hash of a password.
+    
+    Args:
+        password: Plain password
+        
+    Returns:
+        str: Hashed password
+    """
+    return pwd_context.hash(password)

app/crud/__init__.py

@@ -0,0 +1,6 @@
+# flake8: noqa
+
+from . import inventory, product, user
+
+# Make all CRUD modules available in this module
+__all__ = ["inventory", "product", "user"]

app/crud/inventory.py

@@ -0,0 +1,228 @@
+from typing import Any, Dict, List, Optional, Union
+
+from sqlalchemy.orm import Session
+
+from app.models.inventory import InventoryItem, InventoryStatus, InventoryTransaction
+from app.schemas.inventory import (
+    InventoryItemCreate,
+    InventoryItemUpdate,
+    InventoryTransactionCreate,
+)
+
+
+# Inventory Item CRUD operations
+def get_inventory_item_by_id(db: Session, item_id: str) -> Optional[InventoryItem]:
+    """
+    Get an inventory item by ID.
+    
+    Args:
+        db: Database session
+        item_id: Inventory item ID
+        
+    Returns:
+        Optional[InventoryItem]: Inventory item if found, None otherwise
+    """
+    return db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+
+
+def get_inventory_item_by_product_id(db: Session, product_id: str) -> Optional[InventoryItem]:
+    """
+    Get an inventory item by product ID.
+    
+    Args:
+        db: Database session
+        product_id: Product ID
+        
+    Returns:
+        Optional[InventoryItem]: Inventory item if found, None otherwise
+    """
+    return db.query(InventoryItem).filter(InventoryItem.product_id == product_id).first()
+
+
+def get_all_inventory_items(
+    db: Session, 
+    skip: int = 0, 
+    limit: int = 100,
+    status: Optional[InventoryStatus] = None
+) -> List[InventoryItem]:
+    """
+    Get all inventory items with optional filtering.
+    
+    Args:
+        db: Database session
+        skip: Number of items to skip
+        limit: Maximum number of items to return
+        status: Optional inventory status filter
+        
+    Returns:
+        List[InventoryItem]: List of inventory items
+    """
+    query = db.query(InventoryItem)
+    
+    if status:
+        query = query.filter(InventoryItem.status == status)
+    
+    return query.offset(skip).limit(limit).all()
+
+
+def create_inventory_item(db: Session, *, obj_in: InventoryItemCreate) -> InventoryItem:
+    """
+    Create a new inventory item.
+    
+    Args:
+        db: Database session
+        obj_in: Inventory item creation data
+        
+    Returns:
+        InventoryItem: Created inventory item
+    """
+    db_obj = InventoryItem(
+        product_id=obj_in.product_id,
+        quantity=obj_in.quantity,
+        status=obj_in.status,
+        location=obj_in.location,
+        notes=obj_in.notes,
+    )
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def update_inventory_item(
+    db: Session, 
+    *, 
+    db_obj: InventoryItem, 
+    obj_in: Union[InventoryItemUpdate, Dict[str, Any]]
+) -> InventoryItem:
+    """
+    Update an inventory item.
+    
+    Args:
+        db: Database session
+        db_obj: Inventory item to update
+        obj_in: Inventory item update data
+        
+    Returns:
+        InventoryItem: Updated inventory item
+    """
+    if isinstance(obj_in, dict):
+        update_data = obj_in
+    else:
+        update_data = obj_in.model_dump(exclude_unset=True)
+        
+    for field in update_data:
+        if hasattr(db_obj, field):
+            setattr(db_obj, field, update_data[field])
+            
+    # Auto-update status based on quantity
+    if "quantity" in update_data:
+        if db_obj.quantity <= 0:
+            db_obj.status = InventoryStatus.OUT_OF_STOCK
+        elif db_obj.quantity < 10:  # Arbitrary threshold for low stock
+            db_obj.status = InventoryStatus.LOW_STOCK
+        else:
+            db_obj.status = InventoryStatus.IN_STOCK
+    
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def delete_inventory_item(db: Session, *, item_id: str) -> InventoryItem:
+    """
+    Delete an inventory item.
+    
+    Args:
+        db: Database session
+        item_id: Inventory item ID
+        
+    Returns:
+        InventoryItem: Deleted inventory item
+    """
+    item = db.query(InventoryItem).filter(InventoryItem.id == item_id).first()
+    db.delete(item)
+    db.commit()
+    return item
+
+
+# Inventory Transaction CRUD operations
+def get_transaction_by_id(db: Session, transaction_id: str) -> Optional[InventoryTransaction]:
+    """
+    Get an inventory transaction by ID.
+    
+    Args:
+        db: Database session
+        transaction_id: Transaction ID
+        
+    Returns:
+        Optional[InventoryTransaction]: Transaction if found, None otherwise
+    """
+    return db.query(InventoryTransaction).filter(InventoryTransaction.id == transaction_id).first()
+
+
+def get_transactions_by_product_id(
+    db: Session, 
+    product_id: str,
+    skip: int = 0,
+    limit: int = 100
+) -> List[InventoryTransaction]:
+    """
+    Get inventory transactions by product ID.
+    
+    Args:
+        db: Database session
+        product_id: Product ID
+        skip: Number of transactions to skip
+        limit: Maximum number of transactions to return
+        
+    Returns:
+        List[InventoryTransaction]: List of inventory transactions
+    """
+    return db.query(InventoryTransaction).filter(
+        InventoryTransaction.product_id == product_id
+    ).order_by(InventoryTransaction.created_at.desc()).offset(skip).limit(limit).all()
+
+
+def create_transaction(
+    db: Session, 
+    *, 
+    obj_in: InventoryTransactionCreate
+) -> InventoryTransaction:
+    """
+    Create a new inventory transaction.
+    
+    Args:
+        db: Database session
+        obj_in: Transaction creation data
+        
+    Returns:
+        InventoryTransaction: Created transaction
+    """
+    db_obj = InventoryTransaction(
+        product_id=obj_in.product_id,
+        quantity_change=obj_in.quantity_change,
+        notes=obj_in.notes,
+        transaction_by=obj_in.transaction_by,
+    )
+    db.add(db_obj)
+    
+    # Update inventory item quantity
+    inventory_item = get_inventory_item_by_product_id(db, product_id=obj_in.product_id)
+    if inventory_item:
+        inventory_item.quantity += obj_in.quantity_change
+        
+        # Update status based on new quantity
+        if inventory_item.quantity <= 0:
+            inventory_item.status = InventoryStatus.OUT_OF_STOCK
+        elif inventory_item.quantity < 10:  # Arbitrary threshold for low stock
+            inventory_item.status = InventoryStatus.LOW_STOCK
+        else:
+            inventory_item.status = InventoryStatus.IN_STOCK
+            
+        db.add(inventory_item)
+    
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj

app/crud/product.py

@@ -0,0 +1,259 @@
+from typing import Any, Dict, List, Optional, Union
+
+from sqlalchemy.orm import Session
+
+from app.models.product import Category, Product
+from app.schemas.product import (
+    CategoryCreate,
+    CategoryUpdate,
+    ProductCreate,
+    ProductUpdate,
+)
+
+
+# Product CRUD operations
+def get_product_by_id(db: Session, product_id: str) -> Optional[Product]:
+    """
+    Get a product by ID.
+    
+    Args:
+        db: Database session
+        product_id: Product ID
+        
+    Returns:
+        Optional[Product]: Product if found, None otherwise
+    """
+    return db.query(Product).filter(Product.id == product_id).first()
+
+
+def get_product_by_sku(db: Session, sku: str) -> Optional[Product]:
+    """
+    Get a product by SKU.
+    
+    Args:
+        db: Database session
+        sku: Product SKU
+        
+    Returns:
+        Optional[Product]: Product if found, None otherwise
+    """
+    return db.query(Product).filter(Product.sku == sku).first()
+
+
+def get_all_products(
+    db: Session, 
+    skip: int = 0, 
+    limit: int = 100,
+    category_id: Optional[str] = None,
+    active_only: bool = False
+) -> List[Product]:
+    """
+    Get all products with optional filtering.
+    
+    Args:
+        db: Database session
+        skip: Number of products to skip
+        limit: Maximum number of products to return
+        category_id: Optional category ID filter
+        active_only: Only include active products
+        
+    Returns:
+        List[Product]: List of products
+    """
+    query = db.query(Product)
+    
+    if category_id:
+        query = query.filter(Product.category_id == category_id)
+    
+    if active_only:
+        query = query.filter(Product.is_active.is_(True))
+    
+    return query.offset(skip).limit(limit).all()
+
+
+def create_product(db: Session, *, obj_in: ProductCreate) -> Product:
+    """
+    Create a new product.
+    
+    Args:
+        db: Database session
+        obj_in: Product creation data
+        
+    Returns:
+        Product: Created product
+    """
+    db_obj = Product(
+        name=obj_in.name,
+        description=obj_in.description,
+        price=obj_in.price,
+        sku=obj_in.sku,
+        is_active=obj_in.is_active,
+        category_id=obj_in.category_id,
+    )
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def update_product(
+    db: Session, 
+    *, 
+    db_obj: Product, 
+    obj_in: Union[ProductUpdate, Dict[str, Any]]
+) -> Product:
+    """
+    Update a product.
+    
+    Args:
+        db: Database session
+        db_obj: Product to update
+        obj_in: Product update data
+        
+    Returns:
+        Product: Updated product
+    """
+    if isinstance(obj_in, dict):
+        update_data = obj_in
+    else:
+        update_data = obj_in.model_dump(exclude_unset=True)
+        
+    for field in update_data:
+        if hasattr(db_obj, field):
+            setattr(db_obj, field, update_data[field])
+            
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def delete_product(db: Session, *, product_id: str) -> Product:
+    """
+    Delete a product.
+    
+    Args:
+        db: Database session
+        product_id: Product ID
+        
+    Returns:
+        Product: Deleted product
+    """
+    product = db.query(Product).filter(Product.id == product_id).first()
+    db.delete(product)
+    db.commit()
+    return product
+
+
+# Category CRUD operations
+def get_category_by_id(db: Session, category_id: str) -> Optional[Category]:
+    """
+    Get a category by ID.
+    
+    Args:
+        db: Database session
+        category_id: Category ID
+        
+    Returns:
+        Optional[Category]: Category if found, None otherwise
+    """
+    return db.query(Category).filter(Category.id == category_id).first()
+
+
+def get_category_by_name(db: Session, name: str) -> Optional[Category]:
+    """
+    Get a category by name.
+    
+    Args:
+        db: Database session
+        name: Category name
+        
+    Returns:
+        Optional[Category]: Category if found, None otherwise
+    """
+    return db.query(Category).filter(Category.name == name).first()
+
+
+def get_all_categories(db: Session, skip: int = 0, limit: int = 100) -> List[Category]:
+    """
+    Get all categories.
+    
+    Args:
+        db: Database session
+        skip: Number of categories to skip
+        limit: Maximum number of categories to return
+        
+    Returns:
+        List[Category]: List of categories
+    """
+    return db.query(Category).offset(skip).limit(limit).all()
+
+
+def create_category(db: Session, *, obj_in: CategoryCreate) -> Category:
+    """
+    Create a new category.
+    
+    Args:
+        db: Database session
+        obj_in: Category creation data
+        
+    Returns:
+        Category: Created category
+    """
+    db_obj = Category(
+        name=obj_in.name,
+        description=obj_in.description,
+    )
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def update_category(
+    db: Session, 
+    *, 
+    db_obj: Category, 
+    obj_in: Union[CategoryUpdate, Dict[str, Any]]
+) -> Category:
+    """
+    Update a category.
+    
+    Args:
+        db: Database session
+        db_obj: Category to update
+        obj_in: Category update data
+        
+    Returns:
+        Category: Updated category
+    """
+    if isinstance(obj_in, dict):
+        update_data = obj_in
+    else:
+        update_data = obj_in.model_dump(exclude_unset=True)
+        
+    for field in update_data:
+        if hasattr(db_obj, field):
+            setattr(db_obj, field, update_data[field])
+            
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def delete_category(db: Session, *, category_id: str) -> Category:
+    """
+    Delete a category.
+    
+    Args:
+        db: Database session
+        category_id: Category ID
+        
+    Returns:
+        Category: Deleted category
+    """
+    category = db.query(Category).filter(Category.id == category_id).first()
+    db.delete(category)
+    db.commit()
+    return category

app/crud/user.py

@@ -0,0 +1,186 @@
+from typing import Any, Dict, List, Optional, Union
+
+from sqlalchemy.orm import Session
+
+from app.core.security import get_password_hash, verify_password
+from app.models.user import User, UserRole
+from app.schemas.user import UserCreate, UserUpdate
+
+
+def get_by_id(db: Session, user_id: str) -> Optional[User]:
+    """
+    Get a user by ID.
+    
+    Args:
+        db: Database session
+        user_id: User ID
+        
+    Returns:
+        Optional[User]: User if found, None otherwise
+    """
+    return db.query(User).filter(User.id == user_id).first()
+
+
+def get_by_email(db: Session, email: str) -> Optional[User]:
+    """
+    Get a user by email.
+    
+    Args:
+        db: Database session
+        email: User email
+        
+    Returns:
+        Optional[User]: User if found, None otherwise
+    """
+    return db.query(User).filter(User.email == email).first()
+
+
+def get_by_username(db: Session, username: str) -> Optional[User]:
+    """
+    Get a user by username.
+    
+    Args:
+        db: Database session
+        username: Username
+        
+    Returns:
+        Optional[User]: User if found, None otherwise
+    """
+    return db.query(User).filter(User.username == username).first()
+
+
+def get_all(db: Session, skip: int = 0, limit: int = 100) -> List[User]:
+    """
+    Get all users.
+    
+    Args:
+        db: Database session
+        skip: Number of users to skip
+        limit: Maximum number of users to return
+        
+    Returns:
+        List[User]: List of users
+    """
+    return db.query(User).offset(skip).limit(limit).all()
+
+
+def create(db: Session, *, obj_in: UserCreate) -> User:
+    """
+    Create a new user.
+    
+    Args:
+        db: Database session
+        obj_in: User creation data
+        
+    Returns:
+        User: Created user
+    """
+    db_obj = User(
+        email=obj_in.email,
+        username=obj_in.username,
+        hashed_password=get_password_hash(obj_in.password),
+        full_name=obj_in.full_name,
+        role=obj_in.role,
+        is_active=True,
+    )
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def update(
+    db: Session, *, db_obj: User, obj_in: Union[UserUpdate, Dict[str, Any]]
+) -> User:
+    """
+    Update a user.
+    
+    Args:
+        db: Database session
+        db_obj: User to update
+        obj_in: User update data
+        
+    Returns:
+        User: Updated user
+    """
+    if isinstance(obj_in, dict):
+        update_data = obj_in
+    else:
+        update_data = obj_in.model_dump(exclude_unset=True)
+        
+    if update_data.get("password"):
+        hashed_password = get_password_hash(update_data["password"])
+        del update_data["password"]
+        update_data["hashed_password"] = hashed_password
+        
+    for field in update_data:
+        if hasattr(db_obj, field):
+            setattr(db_obj, field, update_data[field])
+            
+    db.add(db_obj)
+    db.commit()
+    db.refresh(db_obj)
+    return db_obj
+
+
+def delete(db: Session, *, user_id: str) -> User:
+    """
+    Delete a user.
+    
+    Args:
+        db: Database session
+        user_id: User ID
+        
+    Returns:
+        User: Deleted user
+    """
+    user = db.query(User).filter(User.id == user_id).first()
+    db.delete(user)
+    db.commit()
+    return user
+
+
+def authenticate(db: Session, *, email: str, password: str) -> Optional[User]:
+    """
+    Authenticate a user.
+    
+    Args:
+        db: Database session
+        email: User email
+        password: User password
+        
+    Returns:
+        Optional[User]: User if authentication successful, None otherwise
+    """
+    user = get_by_email(db, email=email)
+    if not user:
+        return None
+    if not verify_password(password, user.hashed_password):
+        return None
+    return user
+
+
+def is_active(user: User) -> bool:
+    """
+    Check if a user is active.
+    
+    Args:
+        user: User to check
+        
+    Returns:
+        bool: True if the user is active
+    """
+    return user.is_active
+
+
+def is_admin(user: User) -> bool:
+    """
+    Check if a user is an admin.
+    
+    Args:
+        user: User to check
+        
+    Returns:
+        bool: True if the user is an admin
+    """
+    return user.role == UserRole.ADMIN

app/db/__init__.py

@@ -0,0 +1 @@
+# This file makes the directory a Python package

app/db/base.py

@@ -0,0 +1,4 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+# Base class for all SQLAlchemy models
+Base = declarative_base()

app/db/base_class.py

@@ -0,0 +1,16 @@
+from typing import Any
+
+from sqlalchemy.ext.declarative import declared_attr
+from sqlalchemy.orm import as_declarative
+
+
+@as_declarative()
+class Base:
+    """Base class for all SQLAlchemy models."""
+    id: Any
+    __name__: str
+    
+    # Generate __tablename__ automatically
+    @declared_attr
+    def __tablename__(cls) -> str:
+        return cls.__name__.lower()

app/db/deps.py

@@ -0,0 +1,121 @@
+from typing import Generator
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+from pydantic import ValidationError
+from sqlalchemy.orm import Session
+
+from app.core.config import settings
+from app.db.session import SessionLocal
+from app.models.user import User
+from app.schemas.token import TokenPayload
+
+# OAuth2 token URL
+oauth2_scheme = OAuth2PasswordBearer(
+    tokenUrl=f"{settings.API_V1_STR}/auth/login"
+)
+
+
+def get_db() -> Generator:
+    """
+    Get a database session.
+    
+    Yields:
+        Generator: A database session.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+def get_current_user(
+    db: Session = Depends(get_db),
+    token: str = Depends(oauth2_scheme)
+) -> User:
+    """
+    Get the current authenticated user.
+    
+    Args:
+        db: Database session
+        token: JWT token
+        
+    Returns:
+        User: The current user
+        
+    Raises:
+        HTTPException: If authentication fails
+    """
+    try:
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        token_data = TokenPayload(**payload)
+    except (JWTError, ValidationError) as err:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        ) from err
+        
+    user = db.query(User).filter(User.id == token_data.sub).first()
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found"
+        )
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user"
+        )
+    
+    return user
+
+
+def get_current_active_user(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """
+    Get the current active user.
+    
+    Args:
+        current_user: Current user
+        
+    Returns:
+        User: The current active user
+        
+    Raises:
+        HTTPException: If the user is inactive
+    """
+    if not current_user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Inactive user"
+        )
+    return current_user
+
+
+def get_current_admin_user(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """
+    Get the current admin user.
+    
+    Args:
+        current_user: Current user
+        
+    Returns:
+        User: The current admin user
+        
+    Raises:
+        HTTPException: If the user is not an admin
+    """
+    if current_user.role != "admin":
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions"
+        )
+    return current_user

app/db/session.py

@@ -0,0 +1,25 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+from app.core.config import settings
+
+# Create SQLite engine with check_same_thread=False for SQLite
+engine = create_engine(
+    settings.SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}
+)
+
+# Create SessionLocal class for database sessions
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+
+def get_db():
+    """
+    Dependency for FastAPI endpoints that need a database session.
+    Yields a database session and ensures it is closed after use.
+    """
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1,18 @@
+# Import all models here for Alembic to detect
+# These imports are needed for Alembic to detect the models
+# flake8: noqa
+
+from app.models.inventory import InventoryItem, InventoryStatus, InventoryTransaction
+from app.models.product import Category, Product
+from app.models.user import User, UserRole
+
+# Make all models available in this module
+__all__ = [
+    "InventoryItem",
+    "InventoryStatus", 
+    "InventoryTransaction",
+    "Category",
+    "Product",
+    "User",
+    "UserRole"
+]

app/models/inventory.py

@@ -0,0 +1,59 @@
+import enum
+import uuid
+
+from sqlalchemy import (
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.db.base import Base
+
+
+class InventoryStatus(str, enum.Enum):
+    """Enum for inventory status."""
+    IN_STOCK = "in_stock"
+    LOW_STOCK = "low_stock"
+    OUT_OF_STOCK = "out_of_stock"
+    DISCONTINUED = "discontinued"
+
+
+class InventoryItem(Base):
+    """Inventory item model."""
+    __tablename__ = "inventory_items"
+
+    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    quantity = Column(Integer, default=0, nullable=False)
+    status = Column(Enum(InventoryStatus), default=InventoryStatus.OUT_OF_STOCK, nullable=False)
+    location = Column(String, nullable=True)
+    notes = Column(Text, nullable=True)
+    
+    # Foreign keys
+    product_id = Column(String, ForeignKey("products.id"), nullable=False)
+    
+    # Relationships
+    product = relationship("Product", back_populates="inventory_items")
+    
+    # Audit timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+
+class InventoryTransaction(Base):
+    """Inventory transaction model for tracking inventory changes."""
+    __tablename__ = "inventory_transactions"
+
+    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    product_id = Column(String, ForeignKey("products.id"), nullable=False)
+    quantity_change = Column(Integer, nullable=False)  # Positive for additions, negative for subtractions
+    notes = Column(Text, nullable=True)
+    transaction_by = Column(String, ForeignKey("users.id"), nullable=True)
+    
+    # Audit timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)

app/models/product.py

@@ -0,0 +1,54 @@
+import uuid
+
+from sqlalchemy import (
+    Boolean,
+    Column,
+    DateTime,
+    Float,
+    ForeignKey,
+    String,
+    Text,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.db.base import Base
+
+
+class Category(Base):
+    """Category model for product categorization."""
+    __tablename__ = "categories"
+
+    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    name = Column(String, unique=True, index=True, nullable=False)
+    description = Column(Text, nullable=True)
+    
+    # Relationships
+    products = relationship("Product", back_populates="category")
+    
+    # Audit timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+
+class Product(Base):
+    """Product model."""
+    __tablename__ = "products"
+
+    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    name = Column(String, index=True, nullable=False)
+    description = Column(Text, nullable=True)
+    price = Column(Float, nullable=False)
+    sku = Column(String, unique=True, index=True, nullable=False)
+    is_active = Column(Boolean, default=True)
+    
+    # Foreign keys
+    category_id = Column(String, ForeignKey("categories.id"), nullable=True)
+    
+    # Relationships
+    category = relationship("Category", back_populates="products")
+    inventory_items = relationship("InventoryItem", back_populates="product")
+    
+    # Audit timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)

app/models/user.py

@@ -0,0 +1,31 @@
+import enum
+import uuid
+
+from sqlalchemy import Boolean, Column, DateTime, Enum, String
+from sqlalchemy.sql import func
+
+from app.db.base import Base
+
+
+class UserRole(str, enum.Enum):
+    """Enum for user roles."""
+    ADMIN = "admin"
+    CUSTOMER = "customer"
+    STAFF = "staff"
+
+
+class User(Base):
+    """User model."""
+    __tablename__ = "users"
+
+    id = Column(String, primary_key=True, index=True, default=lambda: str(uuid.uuid4()))
+    email = Column(String, unique=True, index=True, nullable=False)
+    username = Column(String, unique=True, index=True, nullable=False)
+    hashed_password = Column(String, nullable=False)
+    full_name = Column(String, nullable=True)
+    role = Column(Enum(UserRole), default=UserRole.CUSTOMER, nullable=False)
+    is_active = Column(Boolean, default=True)
+    
+    # Audit timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)

app/schemas/__init__.py

@@ -0,0 +1,31 @@
+# flake8: noqa
+
+from .auth import Login, TokenResponse
+from .inventory import (
+    InventoryItem,
+    InventoryItemCreate,
+    InventoryItemUpdate,
+    InventoryTransaction,
+    InventoryTransactionCreate,
+)
+from .product import (
+    Category,
+    CategoryCreate,
+    CategoryUpdate,
+    Product,
+    ProductCreate,
+    ProductUpdate,
+)
+from .token import Token, TokenPayload
+from .user import User, UserBase, UserCreate, UserInDB, UserUpdate
+
+# Make all schemas available in this module
+__all__ = [
+    "Login", "TokenResponse",
+    "InventoryItem", "InventoryItemCreate", "InventoryItemUpdate",
+    "InventoryTransaction", "InventoryTransactionCreate",
+    "Category", "CategoryCreate", "CategoryUpdate",
+    "Product", "ProductCreate", "ProductUpdate",
+    "Token", "TokenPayload",
+    "User", "UserBase", "UserCreate", "UserInDB", "UserUpdate"
+]

app/schemas/auth.py

@@ -0,0 +1,13 @@
+from pydantic import BaseModel, EmailStr
+
+
+class Login(BaseModel):
+    """Login schema."""
+    email: EmailStr
+    password: str
+
+
+class TokenResponse(BaseModel):
+    """Token response schema."""
+    access_token: str
+    token_type: str

app/schemas/inventory.py

@@ -0,0 +1,74 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+from app.models.inventory import InventoryStatus
+from app.schemas.product import Product
+
+
+# Inventory item schemas
+class InventoryItemBase(BaseModel):
+    """Base inventory item schema."""
+    product_id: str
+    quantity: int = Field(..., ge=0)
+    status: InventoryStatus = InventoryStatus.OUT_OF_STOCK
+    location: Optional[str] = None
+    notes: Optional[str] = None
+
+
+class InventoryItemCreate(InventoryItemBase):
+    """Inventory item creation schema."""
+    pass
+
+
+class InventoryItemUpdate(BaseModel):
+    """Inventory item update schema."""
+    quantity: Optional[int] = Field(None, ge=0)
+    status: Optional[InventoryStatus] = None
+    location: Optional[str] = None
+    notes: Optional[str] = None
+
+
+class InventoryItem(InventoryItemBase):
+    """Inventory item schema to return to client."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True
+
+
+class InventoryItemWithProduct(InventoryItem):
+    """Inventory item schema with product to return to client."""
+    product: Product
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True
+
+
+# Inventory transaction schemas
+class InventoryTransactionBase(BaseModel):
+    """Base inventory transaction schema."""
+    product_id: str
+    quantity_change: int
+    notes: Optional[str] = None
+    transaction_by: Optional[str] = None
+
+
+class InventoryTransactionCreate(InventoryTransactionBase):
+    """Inventory transaction creation schema."""
+    pass
+
+
+class InventoryTransaction(InventoryTransactionBase):
+    """Inventory transaction schema to return to client."""
+    id: str
+    created_at: datetime
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True

app/schemas/product.py

@@ -0,0 +1,82 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, Field
+
+
+# Category schemas
+class CategoryBase(BaseModel):
+    """Base category schema."""
+    name: str
+    description: Optional[str] = None
+
+
+class CategoryCreate(CategoryBase):
+    """Category creation schema."""
+    pass
+
+
+class CategoryUpdate(BaseModel):
+    """Category update schema."""
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+
+class Category(CategoryBase):
+    """Category schema to return to client."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True
+
+
+# Product schemas
+class ProductBase(BaseModel):
+    """Base product schema."""
+    name: str
+    description: Optional[str] = None
+    price: float = Field(..., gt=0)
+    sku: str
+    is_active: bool = True
+    category_id: Optional[str] = None
+
+
+class ProductCreate(ProductBase):
+    """Product creation schema."""
+    pass
+
+
+class ProductUpdate(BaseModel):
+    """Product update schema."""
+    name: Optional[str] = None
+    description: Optional[str] = None
+    price: Optional[float] = Field(None, gt=0)
+    sku: Optional[str] = None
+    is_active: Optional[bool] = None
+    category_id: Optional[str] = None
+
+
+class ProductWithCategory(ProductBase):
+    """Product schema with category to return to client."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+    category: Optional[Category] = None
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True
+
+
+class Product(ProductBase):
+    """Product schema to return to client."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True

app/schemas/token.py

@@ -0,0 +1,15 @@
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+class Token(BaseModel):
+    """Token schema."""
+    access_token: str
+    token_type: str
+
+
+class TokenPayload(BaseModel):
+    """Token payload schema."""
+    sub: Optional[str] = None
+    exp: Optional[int] = None

app/schemas/user.py

@@ -0,0 +1,59 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, EmailStr
+
+from app.models.user import UserRole
+
+
+# Shared properties
+class UserBase(BaseModel):
+    """Base user schema."""
+    email: Optional[EmailStr] = None
+    username: Optional[str] = None
+    full_name: Optional[str] = None
+    is_active: Optional[bool] = True
+    role: Optional[UserRole] = UserRole.CUSTOMER
+
+
+# Properties to receive via API on creation
+class UserCreate(BaseModel):
+    """User creation schema."""
+    email: EmailStr
+    username: str
+    password: str
+    full_name: Optional[str] = None
+    role: Optional[UserRole] = UserRole.CUSTOMER
+
+
+# Properties to receive via API on update
+class UserUpdate(BaseModel):
+    """User update schema."""
+    email: Optional[EmailStr] = None
+    username: Optional[str] = None
+    password: Optional[str] = None
+    full_name: Optional[str] = None
+    is_active: Optional[bool] = None
+    role: Optional[UserRole] = None
+
+
+# Properties to return to client
+class User(UserBase):
+    """User schema to return to client."""
+    id: str
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True
+
+
+# Properties properties stored in DB
+class UserInDB(User):
+    """User schema for database."""
+    hashed_password: str
+
+    class Config:
+        """Configuration for the schema."""
+        from_attributes = True

main.py

@@ -0,0 +1,64 @@
+
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.openapi.utils import get_openapi
+
+from app.api.api import api_router
+from app.core.config import settings
+
+# Create the app instance
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description="Authentication and Inventory API for ecommerce",
+    version="0.1.0",
+    openapi_url="/openapi.json",
+)
+
+# Configure CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=[origin for origin in settings.BACKEND_CORS_ORIGINS],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Root endpoint
+@app.get("/")
+async def root():
+    """Root endpoint returns basic API information."""
+    return {
+        "title": settings.PROJECT_NAME,
+        "documentation": "/docs",
+        "health_check": "/health"
+    }
+
+# Health check endpoint
+@app.get("/health")
+async def health():
+    """Health check endpoint."""
+    return {"status": "ok"}
+
+# Custom OpenAPI schema
+def custom_openapi():
+    if app.openapi_schema:
+        return app.openapi_schema
+    
+    openapi_schema = get_openapi(
+        title=settings.PROJECT_NAME,
+        version="0.1.0",
+        description="Authentication and Inventory API for ecommerce",
+        routes=app.routes,
+    )
+    
+    app.openapi_schema = openapi_schema
+    return app.openapi_schema
+
+app.openapi = custom_openapi
+
+# Include API router
+app.include_router(api_router)
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/__init__.py

@@ -0,0 +1 @@
+# This file makes the directory a Python package

migrations/env.py

@@ -0,0 +1,81 @@
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+from app.db.base import Base
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        render_as_batch=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        is_sqlite = connection.dialect.name == 'sqlite'
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

migrations/versions/00001_initial_schema.py

@@ -0,0 +1,125 @@
+"""Initial schema
+
+Revision ID: 00001
+Revises: 
+Create Date: 2023-10-01
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '00001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create users table
+    op.create_table(
+        'users',
+        sa.Column('id', sa.String(), nullable=False),
+        sa.Column('email', sa.String(), nullable=False),
+        sa.Column('username', sa.String(), nullable=False),
+        sa.Column('hashed_password', sa.String(), nullable=False),
+        sa.Column('full_name', sa.String(), nullable=True),
+        sa.Column('role', sa.Enum('admin', 'customer', 'staff', name='userrole'), nullable=False),
+        sa.Column('is_active', sa.Boolean(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index(op.f('ix_users_email'), 'users', ['email'], unique=True)
+    op.create_index(op.f('ix_users_id'), 'users', ['id'], unique=False)
+    op.create_index(op.f('ix_users_username'), 'users', ['username'], unique=True)
+
+    # Create categories table
+    op.create_table(
+        'categories',
+        sa.Column('id', sa.String(), nullable=False),
+        sa.Column('name', sa.String(), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index(op.f('ix_categories_id'), 'categories', ['id'], unique=False)
+    op.create_index(op.f('ix_categories_name'), 'categories', ['name'], unique=True)
+
+    # Create products table
+    op.create_table(
+        'products',
+        sa.Column('id', sa.String(), nullable=False),
+        sa.Column('name', sa.String(), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('price', sa.Float(), nullable=False),
+        sa.Column('sku', sa.String(), nullable=False),
+        sa.Column('is_active', sa.Boolean(), nullable=True),
+        sa.Column('category_id', sa.String(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.ForeignKeyConstraint(['category_id'], ['categories.id'], ),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index(op.f('ix_products_id'), 'products', ['id'], unique=False)
+    op.create_index(op.f('ix_products_name'), 'products', ['name'], unique=False)
+    op.create_index(op.f('ix_products_sku'), 'products', ['sku'], unique=True)
+
+    # Create inventory_items table
+    op.create_table(
+        'inventory_items',
+        sa.Column('id', sa.String(), nullable=False),
+        sa.Column('quantity', sa.Integer(), nullable=False),
+        sa.Column('status', sa.Enum('in_stock', 'low_stock', 'out_of_stock', 'discontinued', name='inventorystatus'), nullable=False),
+        sa.Column('location', sa.String(), nullable=True),
+        sa.Column('notes', sa.Text(), nullable=True),
+        sa.Column('product_id', sa.String(), nullable=False),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.ForeignKeyConstraint(['product_id'], ['products.id'], ),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index(op.f('ix_inventory_items_id'), 'inventory_items', ['id'], unique=False)
+
+    # Create inventory_transactions table
+    op.create_table(
+        'inventory_transactions',
+        sa.Column('id', sa.String(), nullable=False),
+        sa.Column('product_id', sa.String(), nullable=False),
+        sa.Column('quantity_change', sa.Integer(), nullable=False),
+        sa.Column('notes', sa.Text(), nullable=True),
+        sa.Column('transaction_by', sa.String(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=False),
+        sa.ForeignKeyConstraint(['product_id'], ['products.id'], ),
+        sa.ForeignKeyConstraint(['transaction_by'], ['users.id'], ),
+        sa.PrimaryKeyConstraint('id'),
+    )
+    op.create_index(op.f('ix_inventory_transactions_id'), 'inventory_transactions', ['id'], unique=False)
+
+
+def downgrade() -> None:
+    # Drop tables in reverse order to handle foreign key constraints
+    op.drop_index(op.f('ix_inventory_transactions_id'), table_name='inventory_transactions')
+    op.drop_table('inventory_transactions')
+    
+    op.drop_index(op.f('ix_inventory_items_id'), table_name='inventory_items')
+    op.drop_table('inventory_items')
+    
+    op.drop_index(op.f('ix_products_sku'), table_name='products')
+    op.drop_index(op.f('ix_products_name'), table_name='products')
+    op.drop_index(op.f('ix_products_id'), table_name='products')
+    op.drop_table('products')
+    
+    op.drop_index(op.f('ix_categories_name'), table_name='categories')
+    op.drop_index(op.f('ix_categories_id'), table_name='categories')
+    op.drop_table('categories')
+    
+    op.drop_index(op.f('ix_users_username'), table_name='users')
+    op.drop_index(op.f('ix_users_id'), table_name='users')
+    op.drop_index(op.f('ix_users_email'), table_name='users')
+    op.drop_table('users')
+    
+    # Drop enum types after tables
+    op.execute('DROP TYPE userrole')
+    op.execute('DROP TYPE inventorystatus')

pyproject.toml

@@ -0,0 +1,48 @@
+[tool.ruff]
+# Enable flake8-bugbear (`B`) rules.
+line-length = 88
+target-version = "py310"
+
+[tool.ruff.lint]
+select = ["E", "F", "B", "I"]
+
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".bzr",
+    ".direnv",
+    ".eggs",
+    ".git",
+    ".git-rewrite",
+    ".hg",
+    ".mypy_cache",
+    ".nox",
+    ".pants.d",
+    ".pytype",
+    ".ruff_cache",
+    ".svn",
+    ".tox",
+    ".venv",
+    "__pypackages__",
+    "_build",
+    "buck-out",
+    "build",
+    "dist",
+    "node_modules",
+    "venv",
+]
+
+# Allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+# Ignore certain errors in migrations
+extend-ignore = [
+    "E501",  # Line too long (migrations can have long lines)
+    "B008",  # Do not perform function call in argument defaults (common in FastAPI)
+]
+
+[tool.ruff.lint.mccabe]
+# Unlike Flake8, default to a complexity level of 10.
+max-complexity = 10
+
+[tool.ruff.lint.isort]
+known-third-party = ["fastapi", "pydantic", "sqlalchemy", "starlette", "uvicorn"]

requirements.txt

@@ -0,0 +1,12 @@
+fastapi>=0.100.0
+uvicorn>=0.23.0
+sqlalchemy>=2.0.0
+alembic>=1.11.0
+pydantic>=2.0.0
+pydantic-settings>=2.0.0
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+python-multipart>=0.0.6
+email-validator>=2.0.0
+python-dotenv>=1.0.0
+ruff>=0.0.282