Implement product catalog API with CRUD operations

- Created FastAPI application with product catalog functionality
- Implemented CRUD operations for products
- Added SQLAlchemy models and Pydantic schemas
- Set up SQLite database with Alembic migrations
- Added health check endpoint
- Updated README with project documentation

generated with BackendIM... (backend.im)

README.md

@@ -1,3 +1,87 @@
-# FastAPI Application
+# Product Catalog API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple product catalog API with CRUD operations built with FastAPI and SQLite.
+
+## Features
+
+- Product management with CRUD operations
+- Product filtering by category
+- Health check endpoint
+- Database migrations using Alembic
+- SQLite database for data storage
+
+## Project Structure
+
+```
+.
+├── app
+│   ├── api
+│   │   ├── api.py            # API router configuration
+│   │   ├── health.py         # Health check endpoint
+│   │   └── products.py       # Product endpoints
+│   ├── crud
+│   │   └── product.py        # CRUD operations for products
+│   ├── db
+│   │   └── database.py       # Database configuration and session
+│   ├── models
+│   │   └── product.py        # SQLAlchemy models
+│   └── schemas
+│       ├── health.py         # Pydantic schemas for health check
+│       └── product.py        # Pydantic schemas for products
+├── migrations                # Alembic migration files
+│   ├── env.py
+│   ├── script.py.mako
+│   └── versions
+│       └── initial_products_table.py
+├── alembic.ini              # Alembic configuration
+├── main.py                  # Application entry point
+└── requirements.txt         # Project dependencies
+```
+
+## Installation
+
+1. Clone the repository
+
+2. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+## Running the Application
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000.
+
+API documentation is available at:
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+### Health Check
+
+- `GET /health` - Get API health status
+
+### Products
+
+- `GET /products` - Get all products (with optional category filter)
+- `POST /products` - Create a new product
+- `GET /products/{product_id}` - Get a specific product
+- `PUT /products/{product_id}` - Update a product
+- `DELETE /products/{product_id}` - Delete a product
+
+## Database
+
+The application uses SQLite as database, stored at `/app/storage/db/db.sqlite`. 
+
+## Database Migrations
+
+Migrations are managed with Alembic.
+
+```bash
+# Apply migrations
+alembic upgrade head
+```

alembic.ini

@@ -0,0 +1,101 @@
+# 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
+
+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/api/api.py

@@ -0,0 +1,7 @@
+from fastapi import APIRouter
+from app.api import products, health
+
+api_router = APIRouter()
+
+api_router.include_router(health.router, prefix="/health", tags=["health"])
+api_router.include_router(products.router, prefix="/products", tags=["products"])

app/api/health.py

@@ -0,0 +1,12 @@
+from fastapi import APIRouter
+from app.schemas.health import HealthCheck
+
+router = APIRouter()
+
+
+@router.get("/", response_model=HealthCheck)
+def health_check():
+    """
+    Health check endpoint.
+    """
+    return HealthCheck(status="ok", version="0.1.0")

app/api/products.py

@@ -0,0 +1,105 @@
+from typing import List, Optional
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from sqlalchemy.orm import Session
+
+from app.db.database import get_db
+from app.models.product import Product as ProductModel
+from app.schemas.product import Product, ProductCreate, ProductUpdate
+from app.crud import product as product_crud
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[Product])
+def get_products(
+    category: Optional[str] = None,
+    skip: int = Query(0, ge=0),
+    limit: int = Query(100, ge=1, le=100),
+    db: Session = Depends(get_db),
+):
+    """
+    Retrieve all products with optional filtering by category.
+    """
+    products = product_crud.get_products(db, skip=skip, limit=limit, category=category)
+    return products
+
+
+@router.post("/", response_model=Product, status_code=status.HTTP_201_CREATED)
+def create_product(
+    product: ProductCreate,
+    db: Session = Depends(get_db),
+):
+    """
+    Create a new product.
+    """
+    db_product = product_crud.get_product_by_sku(db, sku=product.sku)
+    if db_product:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Product with SKU {product.sku} already exists",
+        )
+    return product_crud.create_product(db=db, product=product)
+
+
+@router.get("/{product_id}", response_model=Product)
+def get_product(
+    product_id: int,
+    db: Session = Depends(get_db),
+):
+    """
+    Get a specific product by ID.
+    """
+    db_product = product_crud.get_product(db, product_id=product_id)
+    if db_product is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Product with ID {product_id} not found",
+        )
+    return db_product
+
+
+@router.put("/{product_id}", response_model=Product)
+def update_product(
+    product_id: int,
+    product_update: ProductUpdate,
+    db: Session = Depends(get_db),
+):
+    """
+    Update a product.
+    """
+    db_product = product_crud.get_product(db, product_id=product_id)
+    if db_product is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Product with ID {product_id} not found",
+        )
+        
+    # If SKU is being updated, check if it already exists
+    if product_update.sku is not None and product_update.sku != db_product.sku:
+        existing_product = product_crud.get_product_by_sku(db, sku=product_update.sku)
+        if existing_product:
+            raise HTTPException(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                detail=f"Product with SKU {product_update.sku} already exists",
+            )
+    
+    return product_crud.update_product(db=db, db_product=db_product, product_update=product_update)
+
+
+@router.delete("/{product_id}", status_code=status.HTTP_204_NO_CONTENT)
+def delete_product(
+    product_id: int,
+    db: Session = Depends(get_db),
+):
+    """
+    Delete a product.
+    """
+    db_product = product_crud.get_product(db, product_id=product_id)
+    if db_product is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=f"Product with ID {product_id} not found",
+        )
+    
+    product_crud.delete_product(db=db, db_product=db_product)
+    return None

app/crud/product.py

@@ -0,0 +1,60 @@
+from typing import List, Optional
+from sqlalchemy.orm import Session
+from sqlalchemy import desc
+from app.models.product import Product
+from app.schemas.product import ProductCreate, ProductUpdate
+
+
+def get_product(db: Session, product_id: int) -> Optional[Product]:
+    return db.query(Product).filter(Product.id == product_id).first()
+
+
+def get_product_by_sku(db: Session, sku: str) -> Optional[Product]:
+    return db.query(Product).filter(Product.sku == sku).first()
+
+
+def get_products(
+    db: Session, 
+    skip: int = 0, 
+    limit: int = 100,
+    category: Optional[str] = None
+) -> List[Product]:
+    query = db.query(Product)
+    
+    if category:
+        query = query.filter(Product.category == category)
+        
+    return query.order_by(desc(Product.created_at)).offset(skip).limit(limit).all()
+
+
+def create_product(db: Session, product: ProductCreate) -> Product:
+    db_product = Product(
+        name=product.name,
+        description=product.description,
+        price=product.price,
+        sku=product.sku,
+        stock=product.stock,
+        category=product.category
+    )
+    db.add(db_product)
+    db.commit()
+    db.refresh(db_product)
+    return db_product
+
+
+def update_product(
+    db: Session, db_product: Product, product_update: ProductUpdate
+) -> Product:
+    update_data = product_update.model_dump(exclude_unset=True)
+    
+    for field, value in update_data.items():
+        setattr(db_product, field, value)
+    
+    db.commit()
+    db.refresh(db_product)
+    return db_product
+
+
+def delete_product(db: Session, db_product: Product) -> None:
+    db.delete(db_product)
+    db.commit()

app/db/database.py

@@ -0,0 +1,28 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
+
+def create_db_and_tables():
+    Base.metadata.create_all(bind=engine)
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1 @@
+from app.models.product import Product

app/models/product.py

@@ -0,0 +1,16 @@
+from sqlalchemy import Column, Integer, String, Float, Text, DateTime
+from sqlalchemy.sql import func
+from app.db.database import Base
+
+class Product(Base):
+    __tablename__ = "products"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), nullable=False, index=True)
+    description = Column(Text, nullable=True)
+    price = Column(Float, nullable=False)
+    sku = Column(String(50), unique=True, index=True)
+    stock = Column(Integer, default=0)
+    category = Column(String(50), nullable=True, index=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())

app/schemas/__init__.py

@@ -0,0 +1 @@
+from app.schemas.product import Product, ProductCreate, ProductUpdate, ProductInDB

app/schemas/health.py

@@ -0,0 +1,6 @@
+from pydantic import BaseModel
+
+
+class HealthCheck(BaseModel):
+    status: str = "ok"
+    version: str

app/schemas/product.py

@@ -0,0 +1,38 @@
+from datetime import datetime
+from typing import Optional
+from pydantic import BaseModel, Field
+
+
+class ProductBase(BaseModel):
+    name: str = Field(..., min_length=1, max_length=100, example="Smartphone XYZ")
+    description: Optional[str] = Field(None, example="Latest model with advanced features")
+    price: float = Field(..., gt=0, example=799.99)
+    sku: str = Field(..., min_length=3, max_length=50, example="SM-XYZ-2023")
+    stock: int = Field(0, ge=0, example=25)
+    category: Optional[str] = Field(None, example="Electronics")
+
+
+class ProductCreate(ProductBase):
+    pass
+
+
+class ProductUpdate(BaseModel):
+    name: Optional[str] = Field(None, min_length=1, max_length=100)
+    description: Optional[str] = None
+    price: Optional[float] = Field(None, gt=0)
+    sku: Optional[str] = Field(None, min_length=3, max_length=50)
+    stock: Optional[int] = Field(None, ge=0)
+    category: Optional[str] = None
+
+
+class ProductInDB(ProductBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class Product(ProductInDB):
+    pass

main.py

@@ -0,0 +1,19 @@
+from fastapi import FastAPI
+from app.api.api import api_router
+from app.db.database import create_db_and_tables
+
+app = FastAPI(
+    title="Product Catalog API",
+    description="A simple product catalog API with CRUD operations",
+    version="0.1.0",
+)
+
+@app.on_event("startup")
+def on_startup():
+    create_db_and_tables()
+
+app.include_router(api_router)
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/env.py

@@ -0,0 +1,80 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config, pool
+
+from alembic import context
+
+import sys
+import os
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+# 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.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+from app.models import Product
+from app.db.database import Base
+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():
+    """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"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """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:
+        context.configure(
+            connection=connection, target_metadata=target_metadata
+        )
+
+        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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/initial_products_table.py

@@ -0,0 +1,44 @@
+"""Initial products table
+
+Revision ID: 001
+Revises: 
+Create Date: 2025-05-13
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.create_table(
+        'products',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=100), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('price', sa.Float(), nullable=False),
+        sa.Column('sku', sa.String(length=50), nullable=False),
+        sa.Column('stock', sa.Integer(), nullable=True, default=0),
+        sa.Column('category', sa.String(length=50), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('now()'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('now()'), nullable=True),
+        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)
+    op.create_index(op.f('ix_products_category'), 'products', ['category'], unique=False)
+
+
+def downgrade():
+    op.drop_index(op.f('ix_products_category'), table_name='products')
+    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')

requirements.txt

@@ -0,0 +1,6 @@
+fastapi==0.110.0
+uvicorn==0.27.1
+sqlalchemy==2.0.27
+pydantic==2.5.3
+alembic==1.13.1
+python-dotenv==1.0.0